JP2005352376A - Image forming apparatus and image forming method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus with the technology of efficiently printing in a specific color, the image forming apparatus being capable of a printing operation using toner in a cartridge put in a developing position while selective switching between a plurality of cartridges having toners of the specific color takes place in the developing position. <P>SOLUTION: Information about a printable state for each developing cartridge attached to a developing unit is determined. In the case where at least one of the developing cartridges attached to the developing unit is in a printable state, the printing operation is performed in a mode matching the result of the determination (in a mode in which a printing preparation process is not performed). Thus, after the input of the print request, the printing operation is performed with the developing cartridge in the printable state. Since the time needed to start the printing operation can be shortened, thus, ensuring efficient monochrome printing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus and an image forming method in which one of cartridges mounted in a developing unit is positioned at a developing position and a printing operation of a specific color is performed using toner in the cartridge. Is.

  Conventionally, an image forming apparatus that forms an image using a plurality of developing cartridges is widely known. For example, Patent Document 1 describes a color image forming apparatus including a rotary developing unit in which four developing cartridges are arranged radially around a rotation axis. In this apparatus, one of the four developing cartridges is selectively positioned to face a latent image carrier such as a photosensitive member by rotationally driving the rotation shaft thereof, thereby latent images on the latent image carrier. Is developed and transferred onto an intermediate transfer medium. Then, while switching the developing cartridge, the development and transfer processes are repeated in the same manner as described above to superimpose a plurality of color toner images to form a color image.

  In the color image forming apparatus described above, toners of different colors (yellow, cyan, magenta, and black) are accommodated in the four developing cartridges in order to execute a color image printing operation. For this reason, when a monochrome image is printed using the image forming apparatus, there is a problem that the timing of shortage of black toner is earlier than when a monochrome image is printed by a monochrome-only image forming apparatus. Therefore, in order to solve such a problem, the black developing cartridge is mounted at the position where the developing cartridge for yellow, cyan and / or magenta is installed, and the black toner in the one black developing cartridge is removed. An apparatus that switches to another black developing cartridge when it runs out and executes a monochrome printing operation has been proposed (see, for example, Patent Document 2).

Japanese Patent Laying-Open No. 2003-215862 (5th page, FIG. 1) JP 2002-351190 A (5th and 6th pages, FIG. 4)

  Incidentally, in order to print an image satisfactorily using the toner in the developing cartridge, it is necessary to execute in advance a print preparation process for performing a print preparation operation on the cartridge. As a typical print preparation operation executed during the print preparation process, there is a patch process. For example, in the apparatus described in Patent Document 1, patch processing is executed after warming up of the apparatus or in parallel with the appropriate timing before the printing operation, for example, immediately after the apparatus is turned on. In this patch processing, the optimum values of development bias and exposure power as density control factors that affect image quality are calculated based on the density detection result of a solid image or a halftone image formed as a patch image. Then, when executing the printing operation, the developing bias and the exposure power are set to the optimum values thus obtained. As a result, optimum printing operation conditions can be obtained. Then, by executing the printing operation under the printing operation conditions optimized in this way, an image can be formed with good and stable image quality. Thus, in view of the importance of the print preparation process, various proposals have been made for the print preparation process in the color image forming apparatus.

  On the other hand, in the apparatus described in Patent Document 2, that is, an apparatus in which a plurality of developing cartridges containing black toner are mounted, the print preparation process important for executing a good printing operation is not sufficiently considered. For example, in an apparatus equipped with a plurality of black developing cartridges, a large amount of monochrome printing is continuously performed by performing monochrome printing using toner in the cartridge positioned at the developing position while selectively switching the developing cartridge to the developing position. Can be done automatically. However, at the time of switching the developing cartridge, if the patch processing is not performed on the cartridge to be positioned at the developing position, the patch processing must be executed prior to the printing operation using the cartridge. Printing is temporarily interrupted. As a result, there may be a problem that mass printing cannot be performed efficiently.

  Therefore, for example, as a print preparation process, it is conceivable to apply the patch process described in Patent Document 1 to the cartridge mounted on the developing unit as it is. That is, patch processing is executed on the cartridge positioned at the developing position while sequentially switching the cartridges mounted on the developing unit to the developing position. For this reason, for example, when all black developing cartridges are mounted instead of yellow, cyan and magenta developing cartridges, the patch processing is repeated four times before the printing operation. However, in this case, if the patch processing is completed for one of the developing cartridges attached to the developing unit, the printing operation can be executed by the cartridge, but the patch processing for all the developing cartridges is completed. The printing operation cannot be executed until after the operation is completed. As a result, for example, even when there is a print request from the user during the patch processing, there is a problem that it is necessary to wait for a long time until the apparatus is ready for printing.

  As described above, in spite of the advantages and disadvantages depending on the execution mode of the print preparation process, in the conventional technique, it is possible to execute or not execute the printing operation with each cartridge mounted on the developing unit. Since it was unknown, there was a uniform print preparation operation for all the cartridges as described above, and it was not necessarily efficient.

  The present invention has been made in view of the above problems, and can perform printing operation using toner in a cartridge positioned at the developing position while selectively switching a plurality of cartridges having toner of a specific color to the developing position. An object of the present invention is to provide a technique capable of efficiently printing the specific color in such an image forming apparatus.

  To achieve the above object, the present invention provides a latent image carrier capable of carrying an electrostatic latent image, a development unit in which a plurality of cartridges having toner of a specific color are detachably provided, and the development unit Control means for selectively positioning the formed cartridge at the developing position and executing a printing operation for developing the electrostatic latent image on the latent image carrier using the toner in the cartridge. Determines, for each cartridge mounted on the developing unit, printable information indicating whether the printing operation by the cartridge is feasible or not, and in a manner according to the judgment result, In order to enable the printing operation according to the above, a print preparation process performed before the execution of the printing operation is executed.

  The image forming method according to the present invention includes: a latent image carrier capable of carrying an electrostatic latent image; and a developing unit in which a plurality of cartridges having toner of a specific color are detachably provided. In the image forming method, the cartridge mounted on the cartridge is selectively positioned at the developing position, and the electrostatic latent image on the latent image carrier is developed using the toner in the cartridge. For each cartridge installed in the unit, printable information indicating whether the printing operation by the cartridge is feasible or not is determined, and the printing operation by the cartridge is performed in a manner according to the determination result. In order to make it possible, a print preparation process that is performed before the execution of the printing operation is executed.

In order to develop the electrostatic latent image using the toner contained in the cartridge, that is, to execute the printing operation, a print preparation process is executed to enable the printing operation by the cartridge prior to the printing operation. It is necessary to keep. However, when it is unclear whether the printable information of the cartridge attached to the developing unit, that is, whether the printing operation by the cartridge is feasible or not, for example, the cartridge of the cartridge attached to the developing unit. Even if a part of the print operation is already executable, the uniform print preparation process must be performed as described above, and as a result, the print preparation process is completed before the print operation is performed. It may not be said that the efficiency is necessarily high. Therefore, in the present invention, printable information is determined for each cartridge mounted on the developing unit, and print preparation processing is executed in a manner corresponding to the determination result. That is, by determining the printable information, it becomes clear as a determination result whether or not printing can be performed as it is using each cartridge. Then, according to the determination result, the printing operation is performed without performing the printing preparation process, or the printing preparation process for all or a part of the cartridges is performed prior to the printing operation. In other words, the “execution of the print preparation process in an aspect according to the determination result” of the present invention means the following aspects after grasping the printable / impossible state of each cartridge,
A mode in which print preparation processing is not performed,
A mode in which print preparation processing is performed for some cartridges,
A mode in which print preparation processing is performed for all cartridges
Is meant to run. Therefore, it is possible to efficiently print the specific color.

  Further, the control means permits the execution of the printing operation when at least one of the cartridges mounted on the developing unit is capable of executing the printing operation by performing the printing preparation process. Also good. In the invention configured as described above, if at least one of the cartridges mounted on the developing unit can execute the printing operation by executing the print preparation process, there is another cartridge that cannot execute the printing operation. Even if there is, the printing operation can be executed.

  Further, the control means further includes a first control unit that receives a print request, and a second control unit that executes the print preparation process and the printing operation in response to a control command from the first control unit. Also good. Some image forming apparatuses include a main controller that accepts and analyzes a print request from a host computer or the like, and an engine controller that controls the engine unit such as a developing unit to execute a printing operation, thereby separating the functions of the entire apparatus. Some of them are designed to improve the operation efficiency. In such an image forming apparatus, it is desirable that the main controller functions as the first control unit and the engine controller functions as the second control unit. That is, the main controller accepts a print request from a host computer or the like, and the engine controller executes a print preparation process and a print operation, so that various operations can be processed in parallel, and the above identification can be performed more efficiently. Color printing can be performed.

  If at least one of the cartridges attached to the developing unit is capable of executing a printing operation when the printing request is input, the first control unit performs the printing operation by the cartridge capable of executing the printing operation. It is good also as a structure which gives the said control command which starts to the said 2nd control part. In the invention configured as described above, when at least one of the cartridges mounted on the developing unit is in a state where the printing operation can be performed, the printing operation is immediately performed when a printing request is input. Accordingly, it is possible to shorten the time from when the print request is input to when the printing operation is started.

  When the print request is input, if all of the cartridges attached to the developing unit cannot execute the printing operation, the first control unit is attached to the developing unit as the print preparation process. The control command for performing only a print preparation operation for the priority cartridge before the execution of the print operation in order to enable a print operation by the cartridge as a priority cartridge. May be provided to the second control unit. The second control unit may be configured to execute a printing operation when all of the cartridges mounted on the developing unit cannot be executed when the control command for starting the printing operation is input from the first control unit. As the print preparation process, one of the cartridges installed in the developing unit is set as a priority cartridge, and the cartridge is subjected to the print operation before the execution of the print operation in order to enable the print operation. A configuration may be adopted in which a print preparation processing request signal for requesting permission to execute the print preparation operation for the priority cartridge is output to the first control unit. In the invention configured as described above, even when all of the cartridges attached to the developing unit are in a state where the printing operation cannot be performed, if a print request is input, the cartridges attached to the developing unit By executing the print preparation operation for only one of the cartridges, the print preparation process is completed, and printing is possible with the cartridge subjected to the print preparation operation. That is, when the print preparation operation for one of the cartridges attached to the developing unit is completed, the print preparation is completed. Therefore, since the specific color can be printed in a short time, it is possible to reduce the waiting time until the printing starts after the print request is input.

  If all of the cartridges attached to the developing unit cannot execute the printing operation, the second control unit may perform the printing operation using the cartridge before the execution of the printing operation as the print preparation process. A print preparation process request signal for requesting permission to execute the print preparation operation performed on the cartridge for all the cartridges mounted on the developing unit may be output to the first control unit. In the invention configured as described above, if all of the cartridges attached to the developing unit are in a state where the printing operation cannot be performed, the print preparation operation is collectively performed for all of the plurality of cartridges attached to the developing unit. Done. Therefore, when there is a print request after the completion of the print preparation operation, for example, the toner remaining in the cartridge is displayed while the print operation is being performed using one of the plurality of cartridges attached to the developing unit. Even if the amount decreases and the printing operation cannot be performed, the printing operation can be continued by immediately switching to the next cartridge. In addition, since the print preparation operation is executed in advance for all the cartridges before the print request, the print operation using the toner in each cartridge is continuously executed while selectively switching all the cartridges to the development position. can do. Therefore, the specific color can be printed in a large amount and efficiently.

  In addition, when the control command instructing the start of the printing operation is input from the first control unit while the printing preparation operation is being performed for all the installed cartridges, If at least one of the cartridges attached to the developing unit can execute the printing operation, or after the control command is input from the first control unit, at least one of the cartridges attached to the developing unit. If one can execute the printing operation, the printing preparation operation may be interrupted and the printing operation may be started using a cartridge capable of executing the printing operation. In addition, when the print request is input while the print preparation operation is being executed for all the installed cartridges, the first control unit prints at least one of the cartridges installed in the developing unit. If the operation can be performed, or if at least one of the cartridges attached to the developing unit becomes executable after the print request is input to the first control unit, the print preparation operation The control command for instructing the interruption of the print is given to the second control unit, and after confirming the interruption of the print preparation operation, the control instruction for starting the printing operation using a cartridge capable of executing the printing operation is It is good also as a structure given to a 2nd control part. The second control unit can execute the printing operation by performing the printing preparation operation on one of the mounted cartridges while the printing preparation operation is being executed for all the mounted cartridges. Each time, it is confirmed whether or not the control command for instructing the start of the printing operation is input from the first control unit, and if the control command is input, the print preparation operation is interrupted. The printing operation may be started. In the invention configured as described above, when there is a print request during execution of the print preparation operation for all the cartridges mounted on the developing unit prior to execution of the print operation, the print preparation operation is interrupted. . The printing operation is executed using a cartridge that has been subjected to the print preparation operation and is ready to execute the printing operation among the cartridges mounted on the developing unit. Therefore, it is possible to reduce the waiting time until the start of printing after a print request is input.

  In addition, after confirming the end of the printing operation, the printing preparation operation may be executed for the remaining mounted cartridges that have not been subjected to the printing preparation operation. In the invention configured as described above, after the printing operation is completed, the printing preparation operation is performed for the cartridge that has not been subjected to the printing preparation operation. Therefore, when this print preparation operation is completed, all the cartridges are ready to execute the print operation, and thus the specific color can be printed in a large amount and efficiently.

  In addition, the first control unit selects, as the print preparation process, a cartridge that should be able to execute a printing operation from a cartridge mounted on the developing unit based on the printable information and the print request. In order to enable the printing operation by the cartridge, the control command for performing the print preparation operation for the cartridge before the execution of the printing operation only for the selected cartridge may be given to the second control unit. . In the invention thus configured, a selected cartridge is selected from the cartridges mounted on the developing unit based on printable information of the cartridge and a print request, and a print preparation operation is performed only for the selected cartridge. Therefore, when a large amount of printing is requested, the number of cartridges corresponding to the amount of printing is selected as a selected cartridge, a print preparation operation is executed for the selected cartridge, and printing with the selected cartridge is possible It can be. Further, when only a part of the cartridges mounted on the developing unit is in a state where the printing operation can be performed, the number of cartridges that are insufficient to execute the printing operation based on the printing request is selected as the selection cartridge. It is also possible. As described above, since the print preparation operation is executed for the minimum number of cartridges necessary to execute the printing based on the printable information of the cartridge and the print request, the mass preparation can be efficiently performed and the print preparation operation can be performed. Can prevent the user from waiting more than necessary.

  In addition, the first control unit is configured to be able to select a plurality of different print preparation processes, and based on the printable information and the print request, the plurality of print preparation processes to one print preparation process. It is good also as a structure which gives the said control command which performs this one print preparation process to the said 2nd control part. In the invention configured as described above, prior to execution of the printing operation, one print preparation process is selected and executed from a plurality of different print preparation processes based on the printable information of the cartridge and the print request. . That is, the printing operation by the cartridge can be performed by executing the print preparation process based on the printable information and the print request of the cartridge. Therefore, the printing of the specific color can be efficiently performed according to the printable information of the cartridge and the print request.

  Further, it is desirable that M (M ≧ 2) cartridges are mounted on the developing unit. In the invention configured as described above, even if the remaining amount of toner in one cartridge decreases and the printing operation cannot be performed, the printing operation can be continued by switching to the next cartridge.

  Hereinafter, various embodiments of the image forming apparatus according to the present invention will be described. However, since the apparatus configuration and basic operation of these embodiments are the same and the operation is only partially different, all the embodiments are first described. First, the configuration and operation of the apparatus common to the first embodiment will be described, and then the operation unique to each embodiment will be described.

<Device configuration and basic operation>
Here, an embodiment in which the present invention is embodied in an image forming apparatus (color printer) described in Patent Document 1 will be described with reference to the drawings. In other words, in this embodiment, a description will be given by specifically embodying printing with monochrome toner using black toner accommodated in four developing cartridges, that is, monochrome printing.

  FIG. 1 is a diagram showing the configuration of an image forming apparatus according to the present invention. FIG. 2 is a block diagram showing an electrical configuration of the image forming apparatus of FIG. The apparatus 1 is an image forming apparatus that forms a monochrome image using only black (K) toner. In the image forming apparatus 1, when an image signal is given to the main controller 11 from an external device such as a host computer, the engine controller 10 controls each part of the engine unit EG in accordance with a command from the main controller 11 to obtain a predetermined image. A forming operation is executed, and a monochrome image corresponding to the image signal is formed on the sheet S.

  In the engine unit EG, the photosensitive member 22 is provided to be rotatable in the arrow direction D1 in FIG. Further, a charging unit 23, a rotary developing unit 4 and a cleaning unit 25 are arranged around the photosensitive member 22 along the rotation direction D1. The charging unit 23 is applied with a predetermined charging bias, and uniformly charges the outer peripheral surface of the photoconductor 22 to a predetermined surface potential. The cleaning unit 25 removes toner remaining on the surface of the photosensitive member 22 after primary transfer, which will be described later, and collects it in a waste toner tank provided inside. The photosensitive member 22, the charging unit 23, and the cleaning unit 25 integrally constitute the photosensitive member cartridge 2, and the photosensitive member cartridge 2 is detachably attached to the main body of the apparatus 1 as a whole.

  Then, the light beam L is irradiated from the exposure unit 6 toward the outer peripheral surface of the photosensitive member 22 charged by the charging unit 23. The exposure unit 6 exposes the light beam L onto the photosensitive member 22 in accordance with an image signal given from an external device, and forms an electrostatic latent image corresponding to the image signal. Thus, in this embodiment, the photoconductor 22 corresponds to the “latent image carrier” of the present invention.

  The electrostatic latent image thus formed is developed with toner by the developing unit 4. The developing unit 4 is configured as a support frame 40 that is rotatably provided around a rotation axis that is orthogonal to the paper surface of FIG. To 4Kd, and a rotary drive (not shown) for rotating them integrally. The developing unit 4 is controlled by the engine controller 10. Then, based on a control command given from the main controller 11 to the engine controller 10, the developing unit 4 is driven to rotate, and the developing cartridges 4Ka to 4Kd are selectively brought into contact with the photosensitive member 22 or a predetermined gap. When the toner is positioned at a predetermined developing position facing each other with a gap, toner is applied to the surface of the photosensitive member 22 from the developing roller 44 provided in the developing cartridge. As a result, the electrostatic latent image on the photosensitive member 22 is developed with the toner in the selected developing cartridge (printing operation). The visualization of the electrostatic latent image by the developing cartridge positioned at the developing position in this way corresponds to the “printing operation by the cartridge” of the present invention.

  The toner image developed by the developing unit 4 as described above is primarily transferred onto the intermediate transfer belt 71 of the transfer unit 7 in the primary transfer region TR1. The transfer unit 7 includes an intermediate transfer belt 71 that is stretched around a plurality of rollers 72 to 75, and a drive unit that rotates the roller 73 to rotate the intermediate transfer belt 71 in a predetermined rotation direction D2. Yes. The transfer unit 7 transfers a black toner image formed on the photosensitive member 22 onto the intermediate transfer belt 71 to form a monochrome image, and is taken out from the cassette 8 one by one along the conveyance path F. The monochrome image is secondarily transferred onto the sheet S conveyed to the secondary transfer region TR2.

  At this time, in order to correctly transfer the image on the intermediate transfer belt 71 to a predetermined position on the sheet S, the timing of feeding the sheet S to the secondary transfer region TR2 is managed. Specifically, a gate roller 81 is provided on the transport path F in front of the secondary transfer region TR2, and the gate roller 81 rotates in accordance with the timing of the circumferential movement of the intermediate transfer belt 71. S is sent to the secondary transfer region TR2 at a predetermined timing.

  Further, the sheet S on which the monochrome image is thus formed is conveyed to the discharge tray portion 89 provided on the upper surface portion of the apparatus main body via the fixing unit 9, the pre-discharge roller 82 and the discharge roller 83. Further, when images are formed on both sides of the sheet S, when the rear end portion of the sheet S on which the image is formed on one side as described above is conveyed to the reversal position PR behind the pre-ejection roller 82. The rotation direction of the discharge roller 83 is reversed, whereby the sheet S is conveyed in the direction of the arrow D3 along the reverse conveyance path FR. Then, the sheet is again placed on the transport path F before the gate roller 81. At this time, the image is transferred first on the surface of the sheet S on which the image is transferred in contact with the intermediate transfer belt 71 in the secondary transfer region TR2. It is the opposite surface. In this way, images can be formed on both sides of the sheet S.

  A density sensor 60 is disposed in the vicinity of the roller 75. The density sensor 60 is provided so as to face the surface of the intermediate transfer belt 71 and measures the image density of the toner image formed on the outer peripheral surface of the intermediate transfer belt 71 as necessary. Based on the measurement result, this apparatus adjusts the operating conditions of each part of the apparatus that affects the image quality, for example, the developing bias applied to each developing cartridge, the intensity of the light beam L, and the like.

  The density sensor 60 is configured to output a signal corresponding to the image density of a predetermined area on the intermediate transfer belt 71 using, for example, a reflective photosensor. The CPU 101 can detect the image density of each part of the toner image on the intermediate transfer belt 71 by periodically sampling the output signal from the density sensor 60 while rotating the intermediate transfer belt 71.

  As shown in FIG. 2, each of the developing cartridges 4Ka to 4Kd is provided with memories 91 to 94 for storing data relating to the manufacturing lot and usage history of the developing cartridge, the remaining amount of the built-in toner, and the like. Further, each of the developing cartridges 4Ka to 4Kd is provided with wireless communication devices 49Ka, 49Kb, 49Kc, and 49Kd. Then, if necessary, these selectively communicate with the wireless communication device 109 provided on the main body side in a non-contact manner, and data is transmitted between the CPU 101 and each of the memories 91 to 94 via the interface 105. Various information such as consumable management for the developing cartridge is managed by sending and receiving. In this embodiment, non-contact data transmission / reception is performed using electromagnetic means such as wireless communication. However, a connector is provided on the main body side and each developing cartridge side, and the connector is mechanically fitted. By doing so, you may make it mutually transmit / receive data.

  In FIG. 2, reference numeral 113 denotes an image memory provided in the main controller 11 for storing an image given from an external device such as a host computer via the interface 112, and reference numeral 117 denotes an operation result in the CPU 111 and other results. It is a RAM that temporarily stores data. Reference numeral 106 denotes a ROM for storing a calculation program executed by the CPU 101 and control data for controlling the engine unit EG. Reference numeral 107 denotes a RAM for temporarily storing calculation results in the CPU 101 and other data. is there.

  By the way, in the apparatus configured as described above, a print preparation process for performing a print preparation operation on the developing cartridges 4Ka to 4Kd is executed in advance before the printing operation is performed by the developing cartridges 4Ka to 4Kd. There is a need. In the “print preparation process”, a print preparation operation is performed on the developing cartridges 4Ka to 4Kd in order to enable the printing operation by the developing cartridges 4Ka to 4Kd. In the image forming apparatus according to the present invention, how to execute the print preparation operation for each of the developing cartridges 4Ka to 4Kd (execution mode of “print preparation processing”) is not fixed uniformly. For each of the developing cartridges 4Ka to 4Kd, printable information indicating whether the printing operation by each developing cartridge is feasible or not feasible is determined, and “print preparation processing” is performed according to the determination result. Is configured to run.

  For example, as a result of determining the printable information for each of the developing cartridges 4Ka to 4Kd, (1) all the developing cartridges attached to the developing unit 4 cannot execute the printing operation (2) some developing cartridges execute the printing operation Possible (3) It is possible to know the state of the developing cartridges 4Ka to 4Kd such that all the developing cartridges can execute the printing operation. Therefore, the above-described apparatus is configured to change the execution mode of the “print preparation process” in accordance with the print operation executable state of the developing cartridges 4Ka to 4Kd. Various execution modes of the specific “print preparation process” corresponding to the determination result of the printable information for each of the developing cartridges 4Ka to 4Kd will be described in detail together with the description of the following embodiments.

  This printable information is stored in the RAM 107 of the engine controller 10, and is read by the CPU 101 or updated to new information as necessary. For example, print at an appropriate timing immediately after the device is turned on, when the sleep mode is released, when the device cover that has been opened is closed, or when the replacement operation of the developing cartridge is completed The possible information is read from the RAM 107 by the CPU 101. Then, this printable information is determined, and the print preparation process is executed in a manner corresponding to the determination result. Each of the developing cartridges 4Ka to 4Kd becomes a developing cartridge capable of executing a printing operation by performing a printing preparation operation, and at the same time as the developing cartridge capable of executing the printing operation as described above, or thereafter The printable information stored in the RAM 107 is updated with new information after the print preparation process at an appropriate timing.

  Further, by transferring the printable information about the developing cartridges 4Ka to 4Kd stored in the RAM 107 to the RAM 117 at an appropriate timing, the RAM 107 and the RAM 117 can share the same printable information. In this case, if necessary, the CPU 111 reads out the printable information stored in the RAM 117 and makes a determination, and the CPU 111 gives a control command to the CPU 101 to execute a print preparation process in a mode according to the determination result. Good. Then, the CPU 101 executes print preparation processing in accordance with the control command given from the CPU 111.

  As described above, various configurations for determining printable information can be considered, and specific configurations thereof will be described in detail in the following “Embodiments” section. Further, the timing for transferring the printable information from the RAM 107 to the RAM 117 may be the same as the timing when the printable information stored in the RAM 107 is updated, or may be the timing after that. In short, printable information may be transferred at an optimum timing according to the operation status of the apparatus. In this image forming apparatus, in the “print preparation process”, the following operations and processes are executed as a “print preparation operation”.

(1) Checking operation:
This attachment confirmation operation is an operation for confirming that the developing cartridge is securely attached to the support frame 40 of the developing unit 4. Specifically, the data is transmitted and received between the CPU 101 and each of the memories 91 to 94 by wireless communication performed between the main body side and each developing cartridge side. In this regard, the same applies to the (2) conformity confirmation operation described below. Of course, in addition to the non-contact method such as wireless communication, the attachment confirmation may be performed by a contact method using a limit switch or the like.

(2) Conformity check operation:
This conformity confirmation operation is an operation for confirming that the development cartridge mounted on the support frame 40 of the development unit 4 is a development cartridge that contains black toner. In particular, in this embodiment, a monochrome image forming apparatus is configured by mounting a developing cartridge for black at a position where a developing cartridge for yellow, cyan, and / or magenta used as a color image forming apparatus is installed. Therefore, there is a possibility that a user, an operator, or the like erroneously attaches the developing cartridge. Therefore, the conformity confirmation operation is executed to prevent the development cartridge for yellow, cyan or magenta from being used accidentally.

(3) Life check operation:
This life confirmation operation is an operation for confirming that the toner amount necessary for executing the printing operation remains sufficiently in the developing cartridge mounted on the support frame 40 of the developing unit 4. By executing this life checking operation, problems such as density unevenness and fading of an image formed by the printing operation are prevented in advance.

(4) Stir processing:
This stirring process is a process of rotating the developing roller 44 corresponding to the “toner carrier” of the present invention at least once. The reason for executing this stirring process is as follows. In this type of image forming apparatus, if the printing operation is performed for a long time after the power is off or the operation is stopped without performing the printing operation (image forming operation) even when the power is on, It has been conventionally known that periodic density unevenness may appear. In the present specification, this phenomenon is referred to as “abandoned banding phenomenon”.

  This neglected banding phenomenon is difficult because the toner is left on the developing roller 44 of each developing cartridge for a long time and is not easily separated from the developing roller 44, and the degree is not uniform on the surface of the developing roller 44. It is considered that the toner layer on the developing roller 44 is gradually non-uniform. Therefore, in the image forming apparatus according to this embodiment, when the neglected banding generation requirement such that the period in which the operation is stopped exceeds a predetermined period is satisfied, a signal “stirring is required” is generated to empty the developing roller 44. We are turning. That is, the developing roller 44 is rotated at least once by a rotation drive unit (not shown) on the main body side. As a result, the toner layer on the surface of the developing roller 44 is refreshed and the toner layer in a more uniform state is subjected to the developing process, and therefore, density unevenness due to the neglected banding phenomenon is less likely to occur.

(5) Patch processing (condition control processing):
This patch process is a process for adjusting the printing operation condition when executing the printing operation by the developing cartridge to a predetermined optimum condition. This is a process similar to that conventionally used for stabilizing image quality. In this embodiment, a “patch control required” signal is generated at an appropriate timing immediately after the apparatus is turned on, and patch processing is executed in parallel with warming up of the apparatus. Patch processing is also generated when a “patch control required” signal is generated at the timing when the sleep mode is released, when the device cover that was in the open state is closed, or when the replacement operation of the developing cartridge is completed. Execution request occurs.

  Next, a print preparation process executed prior to the print process in the apparatus shown in FIG. 1 will be described. In the embodiment described below, the execution mode of the print preparation process according to the determination result of the printable information for each of the developing cartridges 4Ka to 4Kd has a feature based on the present invention, and accordingly, the execution mode is slightly different. These differences are mainly described below. In order to facilitate understanding of the content of the invention, a case where four developing cartridges 4Ka to 4Kd are mounted on the developing unit 4 as shown in FIG.

<First Embodiment>
FIG. 3 is a diagram showing an operation in the first embodiment of the image forming apparatus according to the present invention. In the first embodiment, printable information for each of the developing cartridges 4Ka to 4Kd attached to the developing unit 4 is stored in the RAM 107 and the RAM 117. When the main controller 11 determines the printable information stored in the RAM 117, when at least one of the developing cartridges 4Ka to 4Kd attached to the developing unit 4 is in a printable state, The “print preparation process” in a mode corresponding to the determination result is executed. Hereinafter, the operation of the first embodiment will be described in detail.

  When a print request is given from the external device such as a host computer to the main controller 11 via the interface 112, first, the CPU 111 of the main controller 11 reads and determines the printable information for each developing cartridge stored in the RAM 117. To do. As a result of determining the printable information, for example, it may be found that the developing cartridge 4Ka among the developing cartridges 4Ka to 4Kd mounted on the developing unit 4 is in a state capable of executing the printing operation. At this time, in this embodiment, as an aspect of the “print preparation process” according to the determination result, a print preparation process of “an aspect in which the print preparation process is not performed” is executed, and a printing operation is executed as the entire apparatus. Allowed. Thereafter, the main controller 11 immediately gives a print start signal for starting a printing operation using the developing cartridge 4Ka to the engine controller 10 as a control command. Then, in the engine controller 10, the printing operation by the developing unit 4Ka is immediately executed according to the printing start signal. Thus, in this embodiment, the main controller 11 functions as the “first control unit” of the present invention, the engine controller 10 functions as the “second control unit” of the present invention, and the main controller 11 and the engine controller 10 And function as "control means" of the present invention.

  As described above, according to this embodiment, the printable information for each of the developing cartridges 4Ka to 4Kd attached to the developing unit 4 is determined, and the mode according to the determination result (the mode in which the print preparation process is not performed). ) Is executing the print preparation process. Specifically, when a print request is input, the main controller 11 determines printable information about each of the developing cartridges 4Ka to 4Kd stored in the RAM 117, but the developing cartridge mounted on the developing unit 4 Since at least one of the 4Ka to 4Kd (for example, the developing cartridge 4Ka) can execute the printing operation, according to the determination result, the print preparation process is performed in a mode in which the print preparation process is not performed, and the apparatus The engine controller 10 is given a control command for permitting execution of the printing operation and starting the printing operation by the developing cartridge (for example, the developing cartridge 4Ka) that can execute the printing operation. As described above, if at least one of the developing cartridges 4Ka to 4Kd attached to the developing unit 4 is in a state where the printing operation can be executed, the printing operation is immediately executed when a printing request is input. Therefore, after the print request is input, even if there are other development cartridges 4Kb to 4Kd that cannot execute the printing operation, the execution of the printing operation is started by executing the printing operation with the developing cartridge that can execute the printing operation. Time can be shortened, so that monochrome printing can be performed efficiently.

  In this embodiment, the main controller 11 functions as the “first control unit” of the present invention, and the engine controller 10 functions as the “second control unit” of the present invention. That is, the main controller 11 receives a print request from a host computer or the like, and the engine controller 10 executes a print preparation process and a printing operation. As described above, by providing a plurality of control units and assigning various operations to the respective control units and separating the functions, parallel processing of various operations can be performed. Therefore, monochrome printing can be performed more efficiently.

Second Embodiment
FIG. 4 is a diagram showing an operation in the second embodiment of the image forming apparatus according to the present invention. FIG. 5 is a flowchart showing the first print preparation process. The second embodiment is greatly different from the first embodiment described above. When a print request is input to the main controller 11, the printable information stored in the RAM 117 is determined, and as a result, it is attached to the developing unit 4. Since all of the developing cartridges 4Ka to 4Kd cannot execute the printing operation, the print preparation process of “an aspect in which the print preparation process is performed for some cartridges” is executed as the “print preparation process”. Hereinafter, the differences from the first embodiment will be mainly described.

  In the second embodiment, when a print request is given from an external device such as a host computer via the interface 112, the main controller 11 first reads and determines printable information stored in the RAM 117. As a result, it has been found that all the developing cartridges 4Ka to 4Kd attached to the developing unit 4 are in a state in which the printing operation cannot be performed. As an aspect, the print preparation process of “an aspect in which the print preparation process is performed for some cartridges” is executed. Specifically, the main controller 11 sets one developing cartridge among the developing cartridges 4Ka to 4Kd attached to the developing unit 4 as a priority cartridge, and performs a print preparation processing instruction signal for executing a print preparation operation only for the priority cartridge. Is given to the engine controller 10 as a control command (see FIG. 4). Then, the CPU 101 controls each part of the apparatus according to the program stored in the ROM 106, and the first print preparation process shown in FIG. 5 is executed. Hereinafter, the first print preparation process will be described in detail with reference to FIGS.

  First, data is transmitted and received between the CPU 101 and each of the memories 91 to 94 by wireless communication, and various types of information such as consumable management regarding the developing cartridges 4Ka to 4Kd are temporarily stored in the RAM 107. In this embodiment, based on information stored in the memory 107 in accordance with an instruction from the main controller 11, the developing cartridge 4Ka closest to the developing position among the mounted cartridges 4Ka to 4Kd is set as the “priority cartridge” of the present invention. For the developing cartridge 4Ka, the mounting confirmation operation (step S1), the conformity confirmation operation (step S2), and the life confirmation operation (step S3) are executed.

  In step S4, it is determined whether or not a “stirring required” signal is generated. This is a process for preventing the neglected banding phenomenon. Accordingly, when the “stirring required” signal is not generated, the process proceeds to step S6 as it is, whereas when the signal is generated, the stirring process (step S5) shown in FIG. 6 is performed for the developing cartridge 4Ka. Executed.

  FIG. 6 is a flowchart showing the stirring process in the first print preparation process of FIG. In this stirring process, among the four developing cartridges, the cartridge 4Ka is moved to the developing position (step S51). As a result, the developing roller 44 of the developing cartridge 4Ka is mechanically connected to the rotation drive unit on the main body side. Then, the developing roller 44 is rotated at least once by the rotation driving unit to refresh the toner layer on the surface of the developing roller 44, and the developing cartridge 4Ka is stirred (step S52).

  When the stirring process (step S5) is completed in this way, the process proceeds to step S6 to determine whether or not a “patch control required” signal is generated. This is a process for adjusting the printing operation condition to a predetermined optimum condition. Therefore, if the “patch control required” signal is not generated, the development unit 4 is moved to the home position (HP) (step S8), and then the first print preparation process is finished as it is. If the signal is generated, the patch processing (step S7) shown in FIG. 7 is executed for the developing cartridge 4Ka.

  FIG. 7 is a flowchart showing patch processing in the first print preparation processing of FIG. In this patch processing, in order to maintain an image formed by executing a printing operation with a constant image quality, a patch image is formed while changing various printing operation conditions, and the image density is detected. Is a process of adjusting the printing operation condition based on the above. In this patch processing, the development bias and exposure power are adjusted as control factors that affect the image quality among the operation parameters that determine the operation conditions of each part of the apparatus. Various other operating parameters that function as control factors are known, and there are many well-known techniques for the principle and control method of image quality control using them. Briefly described.

  First, for the developing cartridge 4Ka, the optimum developing bias, that is, the optimum value of the developing bias applied to the developing roller 44 during the printing operation is calculated. Specifically, the developing cartridge 4Ka is selectively moved to the developing position (step S70), and a patch image having a predetermined pattern is formed with each bias value while changing the developing bias in multiple stages for the developing cartridge 4Ka. (Step S71). Then, the image density of each patch image is detected by the density sensor 60 (step S72).

  When the image density of each patch image is obtained, the relationship between the development bias and the image density can be found from these values. Based on this relationship, the development bias value that matches the predetermined target density Is calculated. Thereby, the optimum developing bias is obtained (step S73). However, if the optimum value is not within the development bias variable range in the apparatus, the value closest to the optimum value calculated in the variable range is set as the optimum development bias.

  When the optimum developing bias is obtained for the developing cartridge 4Ka in this way, the optimum exposure power for the developing cartridge 4Ka, that is, the intensity of the light beam L when forming an electrostatic latent image corresponding to the cartridge on the photosensitive member 22 is subsequently obtained. Is calculated (steps S74 to S76). The processing here is the same as the above-described optimum development bias calculation processing (steps S70 to S73) except that the control factor is exposure power instead of the development bias, but a patch image to be formed as necessary. These image patterns may be different. In this case, it is preferable to use the optimum value obtained previously as the setting value of the developing bias. In this way, the optimum developing bias and optimum exposure power are respectively obtained for the developing cartridge 4Ka, and the patch processing is ended.

  By executing such a print preparation operation (mounting confirmation operation, conformity confirmation operation, life confirmation operation, agitation processing, patch processing), the developing cartridge 4Ka is in a printable state in which the printing operation can be performed satisfactorily. Returning to FIG. 5, the developing unit 4 is moved to the home position (HP) and waits (step S8). By executing the subsequent printing operation under the optimum conditions, it is possible to form an image with a desired image quality and stably.

  After the first print preparation process is completed in this way, the engine controller 10 outputs a print preparation process end signal indicating the completion of the print preparation process to the main controller 11, and the entire apparatus performs a printing operation. Execution is allowed. After confirming the print preparation process end signal, the main controller 11 executes the printing operation by giving the engine controller 10 a printing start signal for starting the printing operation based on the printing request as a control command.

  As described above, in the second embodiment, printable information about each of the developing cartridges 4Ka to 4Kd is determined prior to the execution of the printing operation, and an aspect corresponding to the determination result (print preparation processing for some cartridges). The print preparation process is executed in the mode of Specifically, as a result of determining the printable information for each of the developing cartridges 4Ka to 4Kd, all the developing cartridges 4Ka to 4Kd attached to the developing unit 4 are in a state where the printing operation cannot be performed. Since the print request has been input, the print preparation process is completed only for the developing cartridge 4Ka, thereby completing the print preparation process, leading to a state in which the printing operation by the developing cartridge 4Ka is possible. That is, when the print preparation operation for one of the developing cartridges 4Ka to 4Kd mounted in the developing unit 4 (corresponding to the “priority cartridge” of the present invention) is completed, the printing preparation is completed. Therefore, since it is possible to print in a short time, it is possible to reduce the waiting time until the start of printing after a print request is input. Therefore, it is possible to prevent the user from waiting more than necessary for the print preparation process, to reduce the waiting time of the user, and to perform monochrome printing efficiently.

<Third Embodiment>
FIG. 8 is a diagram showing an operation in the third embodiment of the image forming apparatus according to the present invention. The third embodiment is greatly different from the second embodiment in that the engine controller 10 reads out and determines printable information about the developing cartridges 4Ka to 4Kd stored in the RAM 107. When a print request is input to the main controller 11, the main controller 11 does not determine printable information for each of the developing cartridges 4Ka to 4Kd and sends a print start signal for starting a printing operation as a control command to the engine controller 10. Give to. Hereinafter, the differences from the second embodiment will be mainly described.

  In the third embodiment, when a print request is input to the main controller 11, the main controller 11 does not determine printable information about each of the developing cartridges 4Ka to 4Kd, and starts printing operation as a control command. A start signal is given to the engine controller 10. Then, the engine controller 10 reads and determines printable information for each of the developing cartridges 4Ka to 4Kd stored in the RAM 107 in response to the control command (print start signal). In this embodiment, since all the developing cartridges 4Ka to 4Kd attached to the developing unit 4 are in a state in which the printing operation cannot be performed, “partial printing preparation processing” according to the determination result is “partial”. The print preparation process of “Aspect for Performing Print Preparation Process for No. of Cartridges” is executed. Specifically, the engine controller 10 sets one of the developing cartridges attached to the developing unit 4 as a priority cartridge, and outputs a print preparation processing request signal for requesting permission to execute a print preparation operation only for the priority cartridge. It outputs to the controller 11 (refer FIG. 8).

  After confirming the print preparation process request signal, the main controller 11 provides the engine controller 10 with a print preparation process instruction signal for executing a print preparation operation for the priority cartridge. In response to the print preparation process instruction signal, the engine controller 10 executes the first print preparation process in which the print preparation operation is performed only for the priority cartridge among the development cartridges 4Ka to 4Kd mounted on the development unit 4, thereby printing the apparatus. Leading to a possible state. Then, the engine controller 10 executes a printing operation after the first print preparation process is completed.

  As described above, in the third embodiment, as a result of determining the printable information for each of the developing cartridges 4Ka to 4Kd, the print preparation operation is necessary for all the developing cartridges 4Ka to 4Kd attached to the developing unit 4. However, among the developing cartridges 4Ka to 4Kd attached to the developing unit 4, only the developing cartridge 4Ka (priority cartridge) is subjected to the print preparation operation to finish the print preparation process, and the developing cartridge 4Ka is used. This leads to a state where a printing operation is possible. That is, when the print preparation operation for the priority cartridge (development cartridge 4Ka) among the development cartridges 4Ka to 4Kd mounted on the development unit 4 is completed, the print preparation is completed. The waiting time until the start can be shortened.

<Fourth embodiment>
FIG. 9 is a diagram showing an operation in the fourth embodiment of the image forming apparatus according to the present invention. This embodiment differs greatly from the third embodiment described above in that a print start signal is not given from the main controller 11 to the engine controller 10, and the “print preparation process for all cartridges” is an example of the “print preparation process”. The printing preparation process of “mode to perform” is executed. Hereinafter, the differences from the third embodiment will be mainly described.

  In the fourth embodiment, the CPU 101 (engine controller) is used at an arbitrary timing (for example, an appropriate timing immediately after the power of the device is turned on) among the timings described in the above section “Configuration and basic operation of the device”. 10) reads out the printable information for each of the developing cartridges 4Ka to 4Kd stored in the RAM 107 and makes a determination. In this embodiment, since all the developing cartridges 4Ka to 4Kd mounted on the developing unit 4 are in a state in which the printing operation cannot be performed, “all printing preparation processing” is set as the “print preparation process” according to the determination result. The print preparation process of “Aspect for Performing Print Preparation Process for No. of Cartridges” is executed. Specifically, the engine controller 10 outputs to the main controller 11 a print preparation process request signal that requests permission to execute the print preparation operation for all of the development cartridges 4Ka to 4Kd attached to the development unit 4 (FIG. 9). reference). After confirming the print preparation process request signal, the main controller 11 gives the engine controller 10 a print preparation process instruction signal for executing a print preparation operation for all the developing cartridges 4Ka to 4Kd as a control command. In response to the print preparation process instruction signal, the engine controller 10 executes a second print preparation process for performing a print preparation operation for all the cartridges 4Ka to 4Kd. The operation of the second print preparation process will be described in detail with reference to FIGS. In addition, about the operation | movement similar to the said 1st thru | or 3rd embodiment, the description of the structure and operation | movement is abbreviate | omitted.

  FIG. 10 is a flowchart showing a second print preparation process executed in the fourth embodiment. In the fourth embodiment, the main controller 11 is at a timing after a print preparation process request signal for requesting execution of a print preparation operation for all the developing cartridges 4Ka to 4Kd is output from the engine controller 10 to the main controller 11. As a control command, a print preparation process instruction signal for executing a print preparation operation for all the developing cartridges 4Ka to 4Kd is given to the engine controller 10 (see FIG. 9). In response to this print preparation processing instruction signal, the engine controller 10 causes the CPU 101 to control each part of the apparatus according to a program stored in the ROM 106 to execute the second print preparation processing shown in FIG.

  In the second print preparation process, first, data is transmitted and received between the CPU 101 and each of the memories 91 to 94 by wireless communication, and various types of information such as consumables management for the developing cartridges 4Ka to 4Kd are temporarily stored in the RAM 107. Remembered. Based on the information stored in the memory 107, the mounting confirmation operation (step S21), the conformity confirmation operation (step S22), and the life confirmation operation (step S23) are executed for all the developing cartridges 4Ka to 4Kd.

  In step S24, it is determined whether or not a “stirring required” signal is generated. If the “stirring required” signal is not generated, the process proceeds to step S26 as it is, while if the signal is generated, the stirring process (step S25) shown in FIG. ) Is executed.

  FIG. 11 is a flowchart showing the stirring process in the second printing preparation process. In this stirring process, the first developing cartridge 4Ka among the four developing cartridges is moved to the developing position (step S251). As a result, the developing roller 44 of the developing cartridge 4Ka is mechanically connected to the rotation drive unit on the main body side. Then, the developing roller 44 is rotated at least once by the rotation driving unit to refresh the toner layer on the surface of the developing roller 44, and the developing cartridge 4Ka is agitated (step S252). The processes in steps S251 and S252 are repeatedly executed while “NO” is determined in step S253. That is, the developing roller 44 is rotated at least once while switching each of the developing cartridges 4Kb to 4Kd to the developing position.

  When the stirring process (step S25) is completed in this way, the process proceeds to step S26, and it is determined whether or not the “patch control required” signal is generated. If the “patch control required” signal is not generated, the second printing preparation process is terminated as it is after the development unit 4 is moved to the home position (HP) (step S28). When the signal is generated, the patch processing (step S27) shown in FIG. 12 is executed for all of the developing cartridges 4Ka to 4Kd.

  FIG. 12 is a flowchart showing patch processing in the second print preparation processing. First, for each of the developing cartridges 4Ka to 4Kd, the optimum developing bias, that is, the optimum value of the developing bias applied to the developing roller 44 during the printing operation is calculated. Specifically, one developing cartridge 4Ka is selectively moved to the developing position (step S270), and a patch image of a predetermined pattern is applied to each developing cartridge 4Ka while changing the developing bias in multiple stages. Form (step S271). The image density of each patch image is detected by the density sensor 60 (step S272).

  When the image density of each patch image is obtained, the relationship between the development bias and the image density can be found from these values. Based on this relationship, the development bias value that matches the predetermined target density Is calculated. As a result, the optimum developing bias is obtained (step S273). However, if the optimum value is not within the development bias variable range in the apparatus, the value closest to the optimum value calculated in the variable range is set as the optimum development bias.

  If the optimum developing bias is obtained for one developing cartridge 4Ka in this way, the above processing S270 to S273 is repeated until the processing for all the developing cartridges is completed (step S274). That is, the optimum developing bias is obtained while switching each of the developing cartridges 4Kb to 4Kd to the developing position. By doing so, the optimum developing bias for each of the developing cartridges 4Ka to 4Kd is obtained.

  Subsequently, for each of the developing cartridges 4Ka to 4Kd, the optimum exposure power, that is, the optimum value of the intensity of the light beam L when the electrostatic latent image corresponding to the cartridge is formed on the photosensitive member 22 is calculated (step S275). ~ S279). The processing here is the same as the above-described optimum development bias calculation processing (steps S270 to S274) except that the control factor is exposure power instead of development bias, but a patch image to be formed as necessary. These image patterns may be different. In this case, it is preferable to use the optimum value obtained previously as the setting value of the developing bias. Thus, the optimum developing bias and the optimum exposure power are obtained for all the developing cartridges, and the patch processing is finished.

  By performing such a print preparation operation (mounting confirmation operation, conformity confirmation operation, life confirmation operation, agitation processing, patch processing), all the developing cartridges 4Ka to 4Kd can perform printing with good printing operation. It becomes a state. Then, returning to FIG. 10, the developing unit 4 is moved to the home position (HP) and stands by (step S28), and the second print preparation process is terminated. Thereafter, a print preparation process end signal is output from the engine controller 10 to the main controller 11 (see FIG. 9). By executing the subsequent printing operation under the optimum conditions, it is possible to form an image with a desired image quality and stably.

  As described above, in the fourth embodiment, since it is determined that all the developing cartridges 4Ka to 4Kd attached to the developing unit 4 are in a state in which the printing operation cannot be performed, the developing cartridges 4Ka to 4Kd attached to the developing unit 4 are determined. The print preparation operation is performed for all of the above. Therefore, when there is a print request after the completion of the second print preparation process, while the printing operation is being executed using one of the developing cartridges 4Ka to 4Kd mounted on the developing unit 4, For example, even if the remaining amount of toner in the developing cartridge 4Ka decreases and the printing operation cannot be performed, the printing operation can be continued by immediately switching to the next developing cartridge 4Kb. In addition, since the print preparation operation is executed for all the developing cartridges 4Ka to 4Kd in advance before the printing request, such a continuation process can be applied to all the developing cartridges 4Ka to 4Kd. It can be done in large quantities and efficiently.

<Fifth Embodiment>
FIG. 13 is a diagram showing an operation in the fifth embodiment of the image forming apparatus according to the present invention. This embodiment is greatly different from the fourth embodiment described above in response to a print request given to the main controller 11 during execution of the second print preparation process for performing the print preparation operation for all the developing cartridges 4Ka to 4Kd. Thus, the engine controller 10 determines printable information of the developing cartridges 4Ka to 4Kd during the second print preparation process. Hereinafter, the differences from the fourth embodiment will be mainly described.

  In the fifth embodiment, the engine controller 10 performs an interface 112 from an external device such as a host computer while executing the second print preparation process for performing the print preparation operation for all the developing cartridges 4Ka to 4Kd as in the fourth embodiment. A print request is given to the main controller 11 via. After the print request is input, the main controller 11 gives the engine controller 10 a print start signal for starting a printing operation based on the print request as a control command. The engine controller 10 executes an interrupt process when a print start signal is input. This interrupt process will be described in detail with reference to FIGS. In addition, about the operation | movement similar to the said 4th Embodiment, the description of the structure and operation | movement is abbreviate | omitted.

  FIG. 14 is a diagram showing interrupt processing in the fifth embodiment. This interrupt process is executed in the engine controller 10 when a print start signal is given as a control command from the main controller 11 to the engine controller 10 while the engine controller 10 is executing the second print preparation process. In this interruption process, first, the engine controller 10 reads the printable information of each of the development cartridges 4Ka to 4Kd stored in the RAM 107, and there is a development cartridge that has already been subjected to the print preparation operation and can be printed. Whether or not (step S2001). Hereinafter, the operation in the case where YES is determined in step S2001 and the operation in the case where NO is determined will be described in detail with reference to FIGS.

  15 is a diagram showing the progress of the print preparation operation in the second print preparation process, FIG. 16 is a flowchart showing the second print preparation process, and FIG. 17 is a flowchart showing the patch process in the second print preparation process of FIG. . When the process proceeds from timing t1 to t3 shown in FIG. 15, the process is completed up to phase PH1 of the second print preparation process shown in FIG. 16, and when the process proceeds from timing t4 to t7, the second print preparation shown in FIG. The processing is completed up to the processing phase PH2. Then, when the process proceeds from timing t8 to t15, the process is completed up to the phase PH3 of the second print preparation process shown in FIG. 16, and the second print preparation process is completed. Note that timings t8 to t11 (phase PH31) and timings t12 to t15 (phase PH32) in FIG. 15 correspond to the phases PH31 and PH32 shown in the patch processing of FIG.

  If NO is determined in step S2001 in the flowchart shown in FIG. 14, there may be timings t1 to t11 (phases PH1, PH2, or PH31) in FIG. 15, and the print start signal is sent to the engine controller at these timings. In the case of the input to 10, the process is executed according to the flowchart shown in FIG. 16 until at least the developing cartridge 4Ka becomes a cartridge (printable cartridge) capable of executing the printing operation at the timing of t12 in FIG. Then, when the developing cartridge 4Ka becomes usable at the timing t12 in FIG. 15, YES is determined in step S2001 of the flowchart in FIG. 14, and the process proceeds to step S2002 to interrupt the second print preparation process.

  On the other hand, if YES is determined in step S2001 of the flowchart shown in FIG. 14, the timing may be t12 to t15 (phase PH32) in FIG. 14 (when there is even one printable cartridge) If a print start signal is input to the engine controller 10 at this timing, even if patch processing (exposure power calculation processing) for the next developing cartridge is being executed, the process proceeds to step S2002 in FIG. Immediately suspend the print preparation process.

  Then, after the interrupt process shown in FIG. 14 is completed and the second print preparation process is interrupted, the process returns to FIG. 13 and the engine controller 10 executes a print operation based on the print request.

  As described above, in the fifth embodiment, when there is a print request during the execution of the print preparation operation for all of the developing cartridges 4Ka to 4Kd attached to the developing unit 4 prior to the execution of the printing operation, the engine controller 10 reads out and determines the printable information for each of the developing cartridges 4Ka to 4Kd stored in the RAM 107. As a result of determining the printable information, if at least one developing cartridge is subjected to the print preparation operation and becomes ready for the print operation, the print preparation operation is interrupted. Then, a printing operation is executed using a developing cartridge that has been subjected to a printing preparation operation and is ready for printing among the developing cartridges 4Ka to 4Kd attached to the developing unit 4. As described above, by determining the printable information of each of the developing cartridges 4Ka to 4Kd during the print preparation process, the execution mode of the print preparation process can be changed as appropriate. The waiting time until the start can be shortened.

<Sixth Embodiment>
FIG. 18 is a diagram showing an operation in the sixth embodiment of the image forming apparatus according to the present invention. The sixth embodiment differs greatly from the fifth embodiment described above in that when the print request is given to the main controller 11 during execution of the print preparation process, the main controller 11 performs the print preparation process. The printable information for each of the developing cartridges 4Ka to 4Kd is determined. As the print preparation process for performing the print preparation operation for all the developing cartridges 4Ka to 4Kd, first, the necessary print preparation operation is executed for one developing cartridge so that the printing operation by the one developing cartridge can be performed. A third print preparation process is executed. In this way, when the printing operation by the one developing cartridge becomes possible, the engine controller 10 can perform printing indicating that the printing operation by the one developing cartridge can be executed by the engine controller 10. Output a signal. The main controller 11 receives this printable signal and updates the printable information for the one developing cartridge in the RAM 117 with new information. Thereafter, the same operation is performed while switching the developing cartridges 4Ka to 4Kd to the developing position until all the developing cartridges 4Ka to 4Kd can be printed. Hereinafter, the differences from the fifth embodiment will be mainly described.

  In the sixth embodiment, while the engine controller 10 executes the third print preparation process for performing the print preparation operation for all cartridges as described above, a print request is sent from the external device such as a host computer via the interface 112. It is given to the controller 11. After the print request is input, the main controller 11 executes a printability determination process, determines printable information about each of the developing cartridges 4Ka to 4Kd stored in the RAM 117, and sends the information to the engine controller 10. Then, a print preparation process interruption instruction signal for interrupting the third print preparation process is output as a control command. The engine controller 10 executes the second interrupt process when the print preparation process interruption instruction signal is input. First, the third print preparation process will be described in detail with reference to FIGS. In addition, about the operation | movement similar to above-mentioned 1st thru | or 5th embodiment, the description of the structure and operation | movement is abbreviate | omitted.

  FIG. 19 is a flowchart showing the third print preparation process. In the sixth embodiment, a print preparation processing request signal for requesting execution of a print preparation operation for all of the developing cartridges 4Ka to 4Kd attached to the developing unit 4 is output from the engine controller 10 to the main controller 11. At this time, no print request is given to the main controller 11 from the external device such as a host computer via the interface 112. Therefore, the main controller 11 gives the engine controller 10 a print preparation processing instruction signal for executing a print preparation operation for all the developing cartridges 4Ka to 4Kd as a control command. In response to the print preparation process instruction signal, the CPU 101 controls each part of the apparatus according to the program stored in the ROM 106, and the third print preparation process shown in FIG. 19 is executed.

  In the third print preparation process, first, data is transmitted and received between the CPU 101 and each of the memories 91 to 94 by wireless communication, and various types of information such as consumables management for the developing cartridges 4Ka to 4Kd are temporarily stored in the RAM 107. Remembered. In this embodiment, in accordance with an instruction from the main controller 11, based on information stored in the memory 107, first, among the mounted cartridges 4Ka to 4Kd, the mounting confirmation operation (step) is performed for the developing cartridge 4Ka closest to the developing position. S30), the conformity confirmation operation (step S31) and the life confirmation operation (step S32) are executed.

  In step S33, it is determined whether or not a “stirring required” signal is generated. This is a process for preventing the neglected banding phenomenon. Therefore, when the “stirring required” signal is not generated, the process proceeds to step S35 as it is, while when the signal is generated, the stirring process (step S34) shown in FIG. 20 is performed for the developing cartridge 4Ka. Executed.

  FIG. 20 is a flowchart showing the stirring process in the third print preparation process of FIG. In this stirring process, among the four developing cartridges, the developing cartridge 4Ka is moved to the developing position (step S341). As a result, the developing roller 44 of the developing cartridge 4Ka is mechanically connected to the rotation drive unit on the main body side. Then, the developing roller 44 is rotated at least once by the rotation driving unit to refresh the toner layer on the surface of the developing roller 44, and the developing cartridge 4Ka is stirred (step S342).

  When the agitation process (step S34) is completed in this way, the process proceeds to step S35, and it is determined whether or not a “patch control required” signal is generated. This is a process for adjusting the printing operation condition to a predetermined optimum condition. Therefore, when the “patch control required” signal is not generated, a process (step S37) of transmitting a printable signal for the developing cartridge 4Ka to the main controller 11 is executed. If it has occurred, the patch processing (step S36) shown in FIG. 21 is executed for the developing cartridge 4Ka.

  FIG. 21 is a flowchart showing patch processing in the third print preparation processing of FIG. In this patch processing, the development bias and exposure power are adjusted as control factors that affect the image quality among the operation parameters that determine the operation conditions of each part of the apparatus. Here, only the flow of processing will be briefly described.

  First, for the developing cartridge 4Ka, the optimum developing bias, that is, the optimum value of the developing bias applied to the developing roller 44 during the printing operation is calculated. Specifically, the developing cartridge 4Ka is selectively moved to the developing position (step S360), and a patch image having a predetermined pattern is formed with each bias value while changing the developing bias in multiple stages for the developing cartridge 4Ka. (Step S361). Then, the image density of each patch image is detected by the density sensor 60 (step S362).

  When the image density of each patch image is obtained, the relationship between the development bias and the image density can be found from these values. Based on this relationship, the development bias value that matches the predetermined target density Is calculated. As a result, the optimum developing bias is obtained (step S363). However, if the optimum value is not within the development bias variable range in the apparatus, the value closest to the optimum value calculated in the variable range is set as the optimum development bias.

  When the optimum developing bias is obtained for the developing cartridge 4Ka in this way, the optimum exposure power for the developing cartridge 4Ka, that is, the intensity of the light beam L when forming an electrostatic latent image corresponding to the cartridge on the photosensitive member 22 is subsequently obtained. Is calculated (steps S364 to S366). The processing here is the same as the optimum development bias calculation processing (steps S360 to S363) described above except that the control factor is exposure power instead of the development bias, but if necessary, a patch image to be formed is formed. These image patterns may be different. In this case, it is preferable to use the optimum value obtained previously as the setting value of the developing bias. In this way, the optimum developing bias and optimum exposure power are respectively obtained for the developing cartridge 4Ka, and the patch processing is ended.

  By executing such a print preparation operation (mounting confirmation operation, conformity confirmation operation, life confirmation operation, agitation processing, patch processing), the developing cartridge 4Ka is in a printable state in which the printing operation can be performed satisfactorily. Then, returning to FIG. 19, a printable signal indicating that the developing cartridge 4Ka can execute the printing operation is transmitted to the main controller 11 (step S37). Thereafter, the same operation is repeated for all of the developing cartridges 4Kb to 4Kd, whereby the processing proceeds until each developing cartridge can execute the printing operation (step S38). Then, after the printing preparation operation is completed for all the developing cartridges 4Ka to 4Kd and all the developing cartridges 4Ka to 4Kd are ready for printing, the developing unit 4 is moved to the home position (HP) and waits (step S39). ). Next, the progress of the third print preparation process will be described in detail with reference to FIG.

  FIG. 22 is a diagram showing the progress of the print preparation operation in the third print preparation process shown in FIG. First, the progress of processing when the print preparation operation is being executed for the developing cartridge 4Ka will be described. First, mounting confirmation is performed at timing t1, conformity confirmation at timing t2, and life confirmation at timing t3 (see steps S30 to S32 in FIG. 19). Thereafter, when a signal indicating that stirring is required is generated in step S33 of FIG. 19, the stirring process is executed at timing t4 (see step S34 of FIG. 19). Subsequently, when a signal requiring patch control is generated in step S35 of FIG. 19, patch processing is executed at timing t5 (see step S36 of FIG. 19). At timing t5 when the patch processing is completed, the developing cartridge 4Ka can execute the printing operation, and a printable signal is transmitted to the main controller 11 (see step S37 in FIG. 19). Thereafter, the same operation is repeated with respect to the developing cartridges 4Kb to 4Kd, but the printing operation by each developing cartridge is executed at timings t10, t15, and t20 when the print preparation operation for each developing cartridge is completed and printing becomes possible. A printable signal indicating that it is possible is transmitted to the main controller 11. Next, the operation of the apparatus when a print request is input to the main controller 11 (see FIG. 18) during execution of the third print preparation process in the engine controller 10 will be described in detail with reference to FIG. 23 and FIG. .

  FIG. 23 is a diagram illustrating a printability determination process executed in the main controller 11 when a print request is input to the main controller 11. In this printability determination process, first, printable information on each of the development cartridges 4Ka to 4Kd is read from the RAM 117, and it is determined whether there is a development cartridge capable of executing a printing operation (S3000). As described above, the printable information stored in the RAM 117 is always updated to the latest information by the printable signal transmitted from the engine controller 10 every time one developer cartridge can be printed. If NO is determined here, the process waits until the printing operation by one developing cartridge can be executed (a printable signal is transmitted from the engine controller 10). If YES is determined, a print preparation process interruption instruction signal for instructing interruption of the third print preparation process is transmitted to the engine controller 10 as a control command (step S3001). Then, after the print preparation process interruption instruction signal is transmitted to the engine controller 10, the print enable determination process is terminated. Next, the operation when the engine controller 10 receives this print preparation process interruption instruction signal will be described in detail with reference to FIGS.

  FIG. 24 is a flowchart showing a second interrupt process executed in the engine controller 10 when the engine controller 10 receives a print preparation process interruption instruction signal as a control command from the main controller 11. In this second interrupt process, it is first determined whether or not a print preparation operation is being executed for one developer cartridge (step S3100). Here, YES is determined when the engine controller 10 has input a print preparation process interruption instruction signal from the main controller 11 at timings t6 to t9, t11 to t14, and t16 to t19 in FIG. The timings t1 to t4 are not included in the print ready determination process of FIG. 23 when the print preparation process interruption instruction signal is transmitted (step S3001), at least one developing cartridge can be printed. This is because it is at least necessary that a printable signal for the developing cartridge 4Ka is transmitted to the main controller 10 at the timing t5 in FIG.

  At these timings, when the print preparation process interruption instruction signal is input to the engine controller 10 and YES is determined in step S3100 in FIG. 24, after waiting for the print preparation operation for the one developing cartridge to be completed, Proceed to the next process (any one of timings t10, t15, and t20 in FIG. 22). On the other hand, if NO is determined, the process proceeds directly to the next process (timing t5, t10, t15, or t20 in FIG. 22). In this way, at the timing when the print preparation operation for one developer cartridge is completed, the engine controller 10 interrupts the third print preparation process (step S3101) and ends the second interrupt process.

  Then, after the second interrupt process shown in FIG. 24 ends and the third print preparation process is interrupted, the process returns to FIG. 18 and a print preparation process stop signal is output from the engine controller 10 to the main controller 11. After confirming the print preparation process stop signal, the main controller 11 gives a print start signal for executing a print operation using the development cartridge that can be printed as a control command to the engine controller 10. A printing operation based on the print request is executed.

  As described above, in the sixth embodiment, prior to the execution of the printing operation, the third print preparation process for performing the print preparation operation on all of the developing cartridges 4Ka to 4Kd attached to the developing unit 4 is being executed. When there is a print request, the main controller 11 reads and determines the printable information for each of the developing cartridges 4Ka to 4Kd stored in the RAM 117. As a result of determining the printable information, if the print preparation operation is completed for at least one developing cartridge and the print operation is possible, the third print preparation process is interrupted. Then, a printing operation is executed using a developing cartridge that has been subjected to a printing preparation operation and is ready for printing among the developing cartridges 4Ka to 4Kd mounted in the developing unit 4. As described above, by determining the printable information of each of the developing cartridges 4Ka to 4Kd during the print preparation process, the execution mode of the print preparation process can be changed as appropriate. The waiting time until the start can be shortened.

<Seventh embodiment>
FIG. 25 is a diagram showing operations in the seventh embodiment of the image forming apparatus according to the present invention. The seventh embodiment differs greatly from the fifth embodiment in that the engine controller 10 is attached to the developing unit 4 during execution of a print preparation process for performing a print preparation operation on all the developing cartridges 4Ka to 4Kd. Each time one of the developed cartridges is subjected to the print preparation operation, the printing operation can be executed (the printable information about the developing cartridge stored in the RAM 107 is updated). It is a point to confirm whether or not a print request is input to the engine controller 10. As the print preparation process for performing the print preparation operation for all the developing cartridges 4Ka to 4Kd, first, the necessary print preparation operation is executed for one developing cartridge so that the printing operation by the one developing cartridge can be performed. The fourth print preparation process is executed. As described above, the engine controller 10 confirms whether or not a print start signal is input as a control command from the main controller 11 to the engine controller 10 when the printing operation by the one developing cartridge becomes possible. . Thereafter, the same operation is performed while switching the developing cartridges 4Ka to 4Kd to the developing position until all the developing cartridges 4Ka to 4Kd can be printed. Hereinafter, the differences from the fifth embodiment will be mainly described.

  In the seventh embodiment, during execution of the fourth print preparation process in which the engine controller 10 performs the print preparation operation as described above for all the developing cartridges 4Ka to 4Kd, the external device such as a host computer via the interface 112 is used. A print request is given to the main controller 11. After the print request is input, the main controller 11 gives the engine controller 10 a control command that instructs execution of a print operation based on the print request. The engine controller 10 checks whether or not a print request is input from the main controller 11 to the engine controller 10 every time one developing cartridge can execute a printing operation during execution of the fourth print preparation process. First, the fourth print preparation process will be described in detail with reference to FIGS. In addition, about the operation | movement similar to the above-mentioned 1st thru | or 6th embodiment, the description of the structure and operation | movement is abbreviate | omitted.

  FIG. 26 is a flowchart showing the fourth print preparation process. In the seventh embodiment, a print preparation process request signal for requesting execution of a print preparation operation for all the developing cartridges 4Ka to 4Kd attached to the developing unit 4 is output from the engine controller 10 to the main controller 11. At this time, no print request is given to the main controller 11 from the external device such as a host computer via the interface 112. Therefore, the main controller 11 gives the engine controller 10 a print preparation processing instruction signal for executing a print preparation operation for all the developing cartridges 4Ka to 4Kd as a control command. In response to the print preparation processing instruction signal, the CPU 101 controls each part of the apparatus according to the program stored in the ROM 106, and the fourth print preparation processing shown in FIG. 26 is executed.

  In the fourth print preparation process, first, data is transmitted and received between the CPU 101 and each of the memories 91 to 94 by wireless communication, and various types of information such as consumables management for each of the developing cartridges 4Ka to 4Kd are temporarily stored in the RAM 107. Remembered. In this embodiment, in accordance with an instruction from the main controller 11, based on information stored in the memory 107, first, among the mounted cartridges 4Ka to 4Kd, the mounting confirmation operation (step S40), the conformity confirmation operation (step S41) and the life confirmation operation (step S42) are executed.

  In step S43, it is determined whether or not a “stirring required” signal is generated. This is a process for preventing the neglected banding phenomenon. Therefore, if the “stirring required” signal is not generated, the process proceeds to step S45 as it is. If the signal is generated, the stirring process (step S44) shown in FIG. 27 is performed for the developing cartridge 4Ka. Executed.

  FIG. 27 is a flowchart showing the stirring process in the fourth print preparation process of FIG. In this stirring process, among the four developing cartridges, the developing cartridge 4Ka is moved to the developing position (step S441). As a result, the developing roller 44 of the developing cartridge 4Ka is mechanically connected to the rotation drive unit on the main body side. Then, the developing roller 44 is rotated at least one turn by the rotation driving unit to refresh the toner layer on the surface of the developing roller 44, and the developing cartridge 4Ka is stirred (step S442).

  When the stirring process (step S44) is completed in this way, the process proceeds to step S45, and it is determined whether or not a “patch control required” signal is generated. This is a process for adjusting the printing operation condition to a predetermined optimum condition. Therefore, when the “patch control required” signal is not generated, a process of confirming whether or not the print start signal is input from the main controller 11 to the engine controller 10 (step S47) is executed. On the other hand, when the signal is generated, the patch processing (step S46) shown in FIG. 28 is executed for the developing cartridge 4Ka.

  FIG. 28 is a flowchart showing patch processing in the fourth print preparation processing of FIG. In this patch processing, the development bias and exposure power are adjusted as control factors that affect the image quality among the operation parameters that determine the operation conditions of each part of the apparatus. Here, only the flow of processing will be briefly described.

  First, for the developing cartridge 4Ka, the optimum developing bias, that is, the optimum value of the developing bias applied to the developing roller 44 during the printing operation is calculated. Specifically, the developing cartridge 4Ka is selectively moved to the developing position (step S460), and a patch image of a predetermined pattern is formed with each bias value while changing the developing bias in multiple stages for the developing cartridge 4Ka. (Step S461). Then, the image density of each patch image is detected by the density sensor 60 (step S462).

  When the image density of each patch image is obtained, the relationship between the development bias and the image density can be found from these values. Based on this relationship, the development bias value that matches the predetermined target density Is calculated. As a result, the optimum developing bias is obtained (step S463). However, if the optimum value is not within the development bias variable range in the apparatus, the value closest to the optimum value calculated in the variable range is set as the optimum development bias.

  When the optimum developing bias is obtained for the developing cartridge 4Ka in this way, the optimum exposure power for the developing cartridge 4Ka, that is, the intensity of the light beam L when forming an electrostatic latent image corresponding to the cartridge on the photosensitive member 22 is subsequently obtained. Is calculated (steps S464 to S466). The processing here is the same as the above-described optimum development bias calculation processing (steps S460 to S463) except that the control factor is exposure power instead of the development bias, but if necessary, a patch image to be formed is formed. These image patterns may be different. In this case, it is preferable to use the optimum value obtained previously as the setting value of the developing bias. In this way, the optimum developing bias and optimum exposure power are obtained for the developing cartridge 4Ka, and the patch processing is terminated.

  By executing such a print preparation operation (mounting confirmation operation, conformity confirmation operation, life confirmation operation, agitation processing, patch processing), the developing cartridge 4Ka enters a printable state in which the printing operation can be performed satisfactorily, and the RAM 107 The printable information on the developing cartridge 4Ka stored in the is updated. Then, it is confirmed whether or not a print start signal is input from the main controller 11 to the engine controller 10 as a control command (step S47). Thereafter, while it is determined NO in step S47, the same operation is repeated for all of the developing cartridges 4Kb to 4Kd, and the process proceeds until each developing cartridge can execute the printing operation (step). S48). Then, after the print preparation operation for all the developing cartridges 4Ka to 4Kd is completed and all the developing cartridges 4Ka to 4Kd can be printed (printable information about all the developing cartridges 4Ka to 4Kd stored in the RAM 107 is stored). The development unit 4 is moved to the home position (HP) and waits (step S49). If YES is determined in step S47, the process proceeds to step S49, and the fourth print preparation process is immediately ended. Next, the progress of the fourth print preparation process will be described in detail with reference to FIG.

  FIG. 29 is a diagram showing the progress of the print preparation operation in the fourth print preparation process shown in FIG. First, the progress of processing when the print preparation operation is being executed for the developing cartridge 4Ka will be described. First, mounting confirmation is performed at timing t1, conformity confirmation at timing t2, and life confirmation at timing t3 (see steps S40 to S42 in FIG. 26). Thereafter, if a signal indicating that stirring is required is generated in step S43 in FIG. 26, the stirring process is executed at timing t4 (see step S44 in FIG. 26). Subsequently, when a signal requiring patch control is generated in step S45 in FIG. 26, patch processing is executed at timing t5 (see step S46 in FIG. 26). At the timing t5 when the patch processing ends, the developing cartridge 4Ka can execute the printing operation, and the printable information on the developing cartridge 4Ka stored in the RAM 107 is updated. Then, it is confirmed whether or not a print start signal is input from the main controller 11 to the engine controller 10 as a control command (see step S47 in FIG. 26). Thereafter, the same operation is repeated for the developing cartridges 4Kb to 4Kd, but at the timings t10, t15, and t20 at which printing preparation operations for the respective developing cartridges are completed and printing is possible, a print start signal is sent from the main controller 11. It is confirmed whether or not a control command is input to the engine controller 10.

  Next, the operation of the apparatus when a print request is input to the main controller 11 during execution of the fourth print preparation process will be described in detail (see FIG. 25). After the print request is input, the main controller 11 gives the engine controller 10 a print start signal for starting a printing operation based on the print request as a control command. In the engine controller 10 in which the fourth print preparation process is executed, is the print start signal input from the main controller 11 to the engine controller 10 as a control command at the timings t5, t10, t15, and t20 in FIG. In this case, if a print start signal is input, the fourth print preparation process is interrupted as described above. Then, a printing operation based on the print request is executed in the engine controller 10 (see FIG. 25).

  As described above, in the seventh embodiment, prior to the execution of the printing operation, the fourth print preparation process for performing the print preparation operation on all of the developing cartridges 4Ka to 4Kd attached to the developing unit 4 is being executed. When the print preparation operation for one developer cartridge is completed and the print operation by the developer cartridge can be executed, and the printable information for the developer cartridge stored in the RAM 107 is updated, the engine controller 10 Whether or not a print request is input from the controller 11 is confirmed. If the print request is input, the fourth print preparation process is interrupted. Then, a printing operation is executed using a developing cartridge that has been subjected to a printing preparation operation and is ready for printing among the developing cartridges attached to the developing unit 4. As described above, the printable information of each of the developing cartridges 4Ka to 4Kd is always determined during the print preparation process, and the execution mode of the print preparation process is appropriately changed. Can be shortened.

<Eighth Embodiment>
FIG. 30 is a diagram showing operations in the eighth embodiment of the image forming apparatus according to the present invention. In the eighth embodiment, after the printing operation is completed, the engine controller 10 reads out and determines the printable information for each of the developing cartridges 4Ka to 4Kd stored in the RAM 107, and the print preparation operation is not performed. The print preparation operation is executed for the developing cartridge. Other configurations and operations are the same as those of the fifth embodiment, and the description of the configurations and operations will be omitted.

  In the eighth embodiment, the engine controller 10 interrupts the second print preparation process in accordance with a control command (print start signal) from the main controller 11. Thereafter, the printing operation is started. After the printing operation is completed, the engine controller 10 reads out and determines the printable information for each developing cartridge stored in the RAM 107, and prepares printing for the remaining developing cartridges that are not subjected to the printing preparing operation. Execute the process. Then, after the print preparation operation for all the developing cartridges is completed, the developing unit 4 is moved to the home position (HP) and waits. By executing the subsequent printing operation under this optimum condition, it is possible to stably form an image with a desired image quality.

  As described above, in the eighth embodiment, after the printing operation is completed, the engine controller 10 reads out and determines the printable information about each of the developing cartridges 4Ka to 4Kd stored in the RAM 107, thereby allowing the developing unit 4 to Among the mounted developing cartridges, the developing cartridges that have not been subjected to the print preparation operation can be seen. Then, according to the determination result, a print preparation operation is executed for a developing cartridge that has not been subjected to the print preparation operation. Therefore, when this print preparation process is completed, all the cartridges are ready for printing, so that a large amount of monochrome printing can be performed efficiently. Further, even if the print preparation process for all the developing cartridges 4Ka to 4Kd is interrupted in the middle, it is interrupted only by re-executing a part of the process afterwards instead of all the processes during the print preparation process. Since all the print preparation processes can be completed, there is no need to perform a wasteful process and the efficiency is high.

<Ninth Embodiment>
FIG. 31 is a diagram showing operations in the ninth embodiment of the image forming apparatus according to the present invention. The ninth embodiment is largely different from the eighth embodiment in that after the printing operation is completed, the main controller 11 reads out the printable information about each of the developing cartridges 4Ka to 4Kd stored in the RAM 117 and determines. However, the printing preparation operation is executed for the remaining developing cartridges that have not been subjected to the printing preparation operation. Other configurations and operations are the same as those in the sixth embodiment, and description of the configurations and operations will be omitted.

  In the ninth embodiment, the engine controller 10 interrupts the third print preparation process in accordance with a control command (print preparation process interruption instruction signal) from the main controller 11. Thereafter, a printing operation is started in accordance with a printing start signal from the main controller 11. Then, after the printing operation is completed, a printing end signal is output to the main controller 11. After confirming this print end signal, the main controller 11 reads out and determines the printable information for each developing cartridge stored in the RAM 117, and performs a print preparation operation as a control command to the engine controller 10. A print preparation processing instruction signal is given to the remaining developing cartridges.

  The engine controller 10 executes the print preparation operation for the development cartridge that has not been subjected to the print preparation operation in accordance with the print preparation processing instruction signal for the remaining development cartridges. Then, after the print preparation operation for all the developing cartridges is completed, the developing unit 4 is moved to the home position (HP) and waits. Thereafter, a print preparation process end signal is output from the engine controller 10 to the main controller 11. By executing the subsequent printing operation under this optimum condition, it is possible to stably form an image with a desired image quality.

  As described above, in the ninth embodiment, after the printing operation is completed, the main controller 11 reads out and determines the printable information about each of the developing cartridges 4Ka to 4Kd stored in the RAM 117, thereby allowing the developing unit 4 to Among the mounted developing cartridges, the developing cartridges that have not been subjected to the print preparation operation can be seen. Then, according to the determination result, a print preparation operation is executed for a developing cartridge that has not been subjected to the print preparation operation. Therefore, when this print preparation process is completed, all the cartridges are ready for printing, so a large amount of monochrome printing can be performed efficiently. Further, even if the print preparation process for all the developing cartridges 4Ka to 4Kd is interrupted in the middle, it is interrupted only by re-executing a part of the process afterwards instead of all the processes during the print preparation process. Since all the print preparation processes can be completed, there is no need to perform a wasteful process and the efficiency is high.

<Tenth Embodiment>
FIG. 32 is a diagram showing the operation in the tenth embodiment of the image forming apparatus according to the present invention. The tenth embodiment differs greatly from the first to ninth embodiments described above in that the main controller 11 can print the print information included in the print request and the developing cartridges 4Ka to 4Kd stored in the RAM 117. The information is judged, and based on the printing amount and the number of developing cartridges that can execute the printing operation, the developing cartridge that should be able to print is selected as the selected cartridge, and the printing preparation operation is executed only for the selected cartridge. . Hereinafter, the differences from the first to ninth embodiments will be mainly described with reference to FIGS. 32 to 36.

  FIG. 33 is a diagram illustrating a print information determination process executed when a print request is input to the main controller 11 (see FIG. 32). In this print information determination process, first, the main controller 11 confirms printable information for each of the developing cartridges 4Ka to 4Kd stored in the RAM 117 (step S5000), and is included in the print request input to the main controller 11. Print information to be confirmed is confirmed (step S5001). Then, based on the printable information and the print information confirmed in steps S5000 and S5001, the optimum number of developing cartridges to be made printable by performing a print preparation operation is determined (step S5002). Finally, it is determined which of the developing cartridges mounted on the developing unit 4 is to be selected, and the print information determination process is terminated (step S5003).

  As described above, in this embodiment, the print preparation process of “an aspect in which the print preparation process is performed for some cartridges” is executed as the aspect of the “print preparation process” according to the determination result of the printable information. Specifically, in step S5000, the printable information for each of the development cartridges 4Ka to 4Kd is determined. In addition, when the print information is determined in step S5001, the number of developing cartridges necessary for the printing operation is two. Therefore, in step S5002, the number of developing cartridges to be printed by performing a print preparation operation is determined to be two. In step S5003, the developing cartridges 4Ka and 4Kb closest to the developing position are selected as selection cartridges.

  Subsequently, a print preparation process instruction signal for executing a print preparation operation based on the content determined by the print information determination process is given as a control command from the main controller 11 to the engine controller 10 (see FIG. 32). In accordance with the print preparation process instruction signal, the engine controller 10 executes the fifth print preparation process for the selected cartridge. The fifth print preparation process will be described in detail with reference to FIGS. In addition, about the structure and operation | movement similar to the said 1st thru | or 9th embodiment, the description of the structure and operation | movement is abbreviate | omitted.

  FIG. 34 is a flowchart showing a fifth print preparation process executed in the tenth embodiment. First, data is transmitted and received between the CPU 101 and each of the memories 91 to 94 by wireless communication, and various types of information such as consumable management regarding the developing cartridges 4Ka to 4Kd are temporarily stored in the RAM 107. Based on the information stored in the memory 107, the developing cartridge 4Ka closest to the developing position and the developing cartridge adjacent to the developing cartridge 4Ka among the mounted cartridges 4Ka to 4Kd in accordance with a control command from the main controller 11. 4Kb is set as the “selected cartridge” of the present invention, and the mounting confirmation operation (step S51), the conformity confirmation operation (step S52) and the life confirmation operation (step S53) are executed for the selected cartridges 4Ka and 4Kb.

  In step S54, it is determined whether or not a “stirring required” signal is generated. If the “stirring required” signal is not generated, the process proceeds to step S56 as it is. If the signal is generated, the selected cartridges 4Ka and 4Kb are stirred (step S55) shown in FIG. ) Is executed.

  FIG. 34 is a flowchart showing the stirring process in the fifth print preparation process. In this stirring process, the first developing cartridge 4Ka of the two selected cartridges is moved to the developing position (step S551). As a result, the developing roller 44 of the developing cartridge 4Ka is mechanically connected to the rotation drive unit on the main body side. Then, the developing roller 44 is rotated at least once by the rotation driving unit to refresh the toner layer on the surface of the developing roller 44, and the developing cartridge 4Ka is agitated (step S552). Note that the processes in steps S551 and S552 are repeatedly executed while “NO” is determined in step S553. That is, after the stirring process for the developing cartridge 4Ka is completed, the developing cartridge 4Kb is moved to the developing position, and the developing roller 44 of the cartridge 4Kb is rotated at least once.

  When the stirring process (step S55) is completed in this way, the process proceeds to step S56 to determine whether or not a “patch control required” signal is generated. This is a process for adjusting the printing operation condition to a predetermined optimum condition. Therefore, if the “patch control required” signal is not generated, the development unit 4 is moved to the home position (HP) (step S58), and then the fifth print preparation process is finished as it is. If the signal is generated, the patch processing (step S57) shown in FIG. 36 is executed for the selected cartridges 4Ka and 4Kb.

  FIG. 36 is a flowchart showing patch processing in the fifth print preparation processing. In this patch processing, the development bias and exposure power are adjusted as control factors that affect the image quality among the operation parameters that determine the operation conditions of each part of the apparatus. Here, only the flow of processing will be briefly described.

  First, for each selected cartridge 4Ka, 4Kb, the optimum developing bias, that is, the optimum value of the developing bias applied to the developing roller 44 during the printing operation is calculated. Specifically, one of the selected cartridges 4Ka and 4Kb is selectively moved to the developing position (step S570), and each bias is set while changing the developing bias for the developing cartridge 4Ka in multiple stages. A patch image of a predetermined pattern is formed with the values (step S571). The image density of each patch image is detected by the density sensor 60 (step S572).

  When the image density of each patch image is obtained, the corresponding relationship between the developing bias and the image density is known from these values, so that the image density matches the predetermined target density based on the relationship (573). However, if the optimum value is not within the development bias variable range in the apparatus, the value closest to the optimum value calculated in the variable range is set as the optimum development bias.

  When the optimum developing bias is obtained for one developing cartridge 4Ka in this way, the above processing S570 to S573 is repeated until the processing for all the selected cartridges is completed (step S574). That is, the optimum developing bias is obtained by switching the developing cartridge 4Kb to the developing position. In this way, the optimum developing bias for each selected cartridge 4Ka, 4Kb is obtained.

  Subsequently, for each selected cartridge 4Ka, 4Kb, the optimum exposure power, that is, the optimum value of the intensity of the light beam L when the electrostatic latent image corresponding to the cartridge is formed on the photosensitive member 22 is calculated (step S575). ~ S579). The processing here is the same as the optimum development bias calculation processing (steps S570 to S573) described above except that the control factor is exposure power instead of the development bias, but if necessary, a patch image to be formed is formed. These image patterns may be different. In this case, it is preferable to use the optimum value obtained previously as the setting value of the developing bias. Thus, the optimum developing bias and the optimum exposure power are obtained for all the selected cartridges 4Ka and 4Kb, and the patch process is terminated.

  By executing such a print preparation operation (mounting confirmation operation, conformity confirmation operation, life confirmation operation, agitation processing, patch processing), all the selected cartridges 4Ka and 4Kb can perform printing with good printing operation. It becomes a state. Then, returning to FIG. 34, the developing unit 4 is moved to the home position (HP), and the fifth print preparation process is ended (step S58).

  Then, returning to FIG. 32, a print preparation process end signal indicating that the fifth print preparation process has ended is output from the engine controller 10 to the main controller 11. After confirming the print preparation process end signal, the main controller 11 gives a print start signal for executing a print operation using the selected cartridge that can execute the print operation as a control command to the engine controller 10. A printing operation based on the print request is executed.

  As described above, in the tenth embodiment, the selected cartridge is selected from the developing cartridges mounted on the developing unit 4 based on the printable information and the print request of the developing cartridges 4Ka to 4Kd, and only the selected cartridge is prepared for printing. Operation is performed. Therefore, when a large amount of printing is requested, the number of developing cartridges corresponding to the amount of printing is selected as a selected cartridge, and a print preparation operation is executed for the selected cartridge so that printing by the selected cartridge is possible. State. As described above, since the print preparation operation is executed for the minimum number of developing cartridges necessary to execute printing based on the printable information and the print request of each developing cartridge, mass printing can be performed efficiently, It is possible to prevent the user from waiting more than necessary for the print preparation operation.

<Eleventh embodiment>
FIG. 37 is a flowchart showing the operation of the image forming apparatus according to the eleventh embodiment of the present invention. In the eleventh embodiment, two different print preparation processes can be executed, and the printable information on the developing cartridges 4Ka to 4Kb stored in the RAM 117 read and determined by the main controller 11 and the main controller On the basis of the print request input to 11, one print preparation process is selected from these two print preparation processes, and the selected print preparation process is executed. Hereinafter, the operation executed in the eleventh embodiment will be described in detail with reference to FIG. 37, focusing on differences from the first to tenth embodiments. In addition, about the structure and operation | movement similar to the said 1st thru | or 10th Embodiment, description of the structure and operation | movement is abbreviate | omitted.

  As shown in FIG. 37, the main controller 11 can select the first print preparation process or the second print preparation process based on the printable information and the print request for each of the developing cartridges 4Ka to 4Kd (step S61). . In the eleventh embodiment, the pre-print process shown in FIG. 37 is executed at an appropriate timing before the print operation is executed, and the print preparation process is selected. Specifically, the printable information for the developing cartridges 4Ka to 4Kd stored in the RAM 117 is read by the main controller 11, and when it is determined that the printing operation cannot be performed for all the developing cartridges 4Ka to 4Kd, When a print request has already been input from the host computer or the like to the main controller 11, the first print preparation process is selected (step S62), and when no print request has been input, the second print preparation process is selected (step S63). Thus, the print preparation process based on the printable information of the developing cartridge and the print request is executed. The first print preparation process is the same as the first print preparation process in the second embodiment shown in FIG. 5, and the second print preparation process is the same process as the second print preparation process in the fourth embodiment shown in FIG. The description of the processing flow is omitted.

  In this way, after the print preparation process based on the printable information and the print request for each of the developing cartridges 4Ka to 4Kd is selected in the main controller 11, the execution of the selected print preparation process is instructed as a control command. A print preparation processing instruction signal is given from the main controller 11 to the engine controller 10. Then, according to the print preparation processing instruction signal, the engine controller 10 executes a print preparation operation for each developing cartridge.

  As described above, in the eleventh embodiment, the main controller 11 performs one printing from two different print preparation processes based on printable information and print requests for the developing cartridges 4Ka to 4Kd stored in the RAM 117. Select the preparation process. Then, by giving the engine controller 10 a control command for executing the selected one print preparation process, the engine controller 10 executes the selected one print preparation process. In other words, by executing the print preparation process based on the printable information and the print request for each developing cartridge, the printing operation by the developing cartridge can be enabled. Therefore, monochrome printing can be efficiently performed according to the printable information and the print request.

<Others>
The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, in the above embodiment, a maximum of four developing cartridges can be mounted on the support frame 40 of the developing unit 4, and the developing cartridges 4Ka to 4Kd are mounted at all mounting positions. The present invention can be applied to an apparatus in which a developing cartridge is mounted only at a position. That is, even in an apparatus in which the developing cartridge 4 having a smaller number M (M ≧ 2) of developing cartridges than the number of mountable developing cartridges is mounted on the developing unit 4, printable information on the developing cartridge mounted on the developing unit 4 is determined. By performing the print preparation operation for these developing cartridges, it is possible to obtain the same effects as those described above. In the above embodiment, the number that can be mounted is four, but this number is arbitrary, and the value of M is arbitrary as long as it is 2 or more and not more than the number that can be mounted. Therefore, for example, the developing unit 4 is configured so that the number of support frames 40 that can be mounted is 5 or more, and the yellow, cyan, and magenta developing cartridges are mounted at the three mounting positions, respectively, and the remaining The present invention can also be applied to an image forming apparatus in which a black developing cartridge is mounted at the mounting position.

  In the above embodiment, the development cartridge closest to the development position is set as the priority cartridge or the selection cartridge, and the print preparation operation is performed on the cartridge. However, the print preparation operation may be performed on other development cartridges. I do not care. For example, as described above, various kinds of information such as consumable management related to the developing cartridge are temporarily stored in the RAM 107 before the print preparation process is executed. Therefore, the print preparation process is performed based on a part of the information. The developing cartridge to be performed, that is, the priority cartridge or the selected cartridge may be determined.

  In the first embodiment, the main controller 11 reads and determines the printable information about the developing cartridges 4Ka to 4Kd stored in the RAM 117. However, the engine controller 10 reads the developing cartridges 4Ka to 4K stored in the RAM 107. A configuration may be adopted in which printable information for 4 Kd is read and determined. In this case, for example, when a print request is input to the main controller 11, the main controller 11 does not determine printable information about each of the developing cartridges 4Ka to 4Kd, but as a control command, a print start signal for starting a printing operation. Is given to the engine controller 10. The engine controller 10 may be configured to read and determine printable information for each of the developing cartridges 4Ka to 4Kd stored in the RAM 107 in accordance with this control command (print start signal).

  In the first embodiment, when the main controller 11 determines printable information for each of the developing cartridges 4Ka to 4Kd, only the developing cartridge 4Ka is in a state in which the printing operation can be performed. Similarly, when part or all of 4Kb to 4Kd can execute the printing operation, the same effect as the above-described effect can be obtained by executing the print preparation process in the “mode in which the print preparation process is not performed”. be able to. In this case, the engine controller 10 may of course determine the printable information for each of the developing cartridges 4Ka to 4Kd.

  In the fourth to ninth embodiments, before the print preparation process for performing the print preparation operation for all the development cartridges 4Ka to 4Kd is first executed, the engine controller 10 performs the process for each of the development cartridges 4Ka to 4Kd. Although the printable information is determined, this determination may be made by the main controller 11 reading out the printable information about the developing cartridges 4Ka to 4Kd stored in the RAM 117.

  In the above-described four embodiments, when it is determined that all the developing cartridges 4Ka to 4Kd attached to the developing unit 4 cannot execute the printing operation, the print preparation is performed in the “mode for performing the print preparation process for all the cartridges”. Although the processing is executed, as a result of determining the printable information for each developing cartridge, some of the developing cartridges 4Ka to 4Kd attached to the developing unit 4 are in a state where the printing operation can be performed. In this case, the print preparation operation may be collectively executed for the remaining development cartridges in a state where the print operation cannot be executed. With this configuration, if the print preparation operation is executed only for the development cartridge that needs the print preparation operation, all the development cartridges can be put into a state where the print operation can be executed. There is no need to perform the operation. In this case, the printable information for each of the developing cartridges 4Ka to 4Kd may be determined by the engine controller 11 as a matter of course.

  In the eighth embodiment, the second print preparation process is executed as the print preparation process for performing the print preparation operation for all the cartridges. However, instead of the second print preparation process, all the cartridges are used. Of course, the fourth print preparation process may be executed as the print preparation process for performing the print preparation operation.

  In the tenth embodiment, the main controller 11 determines printable information and print information for each of the developing cartridges 4Ka to 4Kd. However, the engine controller 10 may make this determination. In this case, for example, when a print request is input to the main controller 11, the main controller 11 does not determine printable information about each of the developing cartridges 4Ka to 4Kd, and performs a printing operation based on the print request as a control command. Is supplied to the engine controller 10. Then, the engine controller 10 may be configured to read and determine the print information included in the control command (print start signal) and the printable information for each of the developing cartridges 4Ka to 4Kd stored in the RAM 107.

  In the tenth embodiment, it is determined that all the developing cartridges 4Ka to 4Kd attached to the developing unit 4 cannot execute the printing operation. However, out of the developing cartridges 4Ka to 4Kd attached to the developing unit 4 When some of the developing operations can be performed, it is also possible to select a number of developing cartridges that are insufficient to execute the printing operation based on the print request as the selection cartridge.

  In the eleventh embodiment, the first and second print preparation processes can be selected as selectable print preparation processes, but other print preparation processes (such as the third and fourth print preparation processes) are selected. Of course, it may be configured as possible. Furthermore, the number of print preparation processes that can be selected is not limited to two, and may be three or more. Of course, the engine controller 10 may perform a process of selecting one print preparation process from a plurality of print preparation processes.

  In the above embodiment, when the main controller 11 or the engine controller 10 determines the printable information for each of the developing cartridges 4Ka to 4Kd, a part of the developing cartridges 4Ka to 4Kd is in a state where the printing operation cannot be performed. However, if all the developing cartridges 4Ka to 4Kd are in a state in which the printing operation can be executed, the print preparation process of “a mode in which no print preparation process is performed” may be executed as the print preparation process. With this configuration, the print preparation process can be completed without performing a useless print preparation operation, so that the time until the start of printing can be shortened and the efficiency is high.

  In the above embodiment, the present invention is applied to an image forming apparatus in which the specific color is black, but the specific color is not limited to this.

  In the above-described embodiment, a rotary developing method in which a plurality of developing cartridges are mounted on the developing unit 4 is employed. Therefore, the toner stored in each developing cartridge as the developing unit 4 rotates is stirred in the cartridge. Thus, the toner can be made uniform. Therefore, the toner agitation may be executed by the rotation operation of the developing unit 4 as the print preparation operation. Further, conventionally, there is a case where a member such as an agitator or an auger bar is arranged in the developing cartridge to stir the toner in the developing cartridge or actively supply the toner to the developing roller side. Therefore, in an apparatus equipped with a member such as an agitator or an auger bar, operations such as toner agitation and toner supply by the member may be executed as a print preparation operation.

  Further, in the above-described embodiment, the configuration in which the toner stored in the developing cartridge is used up is adopted. However, in an apparatus employing a replenishing type developing cartridge that replenishes toner as necessary, a toner replenishing operation is performed as a print preparation operation. May be further executed.

  In the above embodiment, the four developing cartridges 4Ka to 4Kd having the same shape are used. However, developing cartridges having different shapes may be used. In the above embodiment, the present invention is applied to a so-called rotary type image forming apparatus in which the rotary developing unit 4 is arranged for one photoconductor 22. The present invention can also be applied to an elevator type image forming apparatus in which a developing cartridge moves up and down and develops with each developing cartridge, or a so-called tandem type image forming apparatus.

  In the above embodiment, the printable information stored in each of the RAM 117 of the main controller 11 and the RAM 107 of the engine controller 10 is read and determined. For example, each of the memories 91 to 94 of the developing cartridges 4Ka to 4Kd is stored. The printable information may be stored, and the printable information stored in the memories 91 to 94 may be read and determined.

  As the print preparation operation to be executed for the developing cartridge, an appropriate one of the above-described various print preparation operations can be used according to the configuration of the apparatus and the operation status.

  Further, the present invention is not limited to the configuration of the above-described embodiment. For example, an apparatus for forming an image of a specific color by installing a development unit equipped with a plurality of development cartridges having toner of a specific color, or a transfer other than an intermediate transfer belt The present invention can be applied to an apparatus including a medium (transfer drum, transfer sheet, etc.), and also to other image forming apparatuses such as a copying machine and a facsimile apparatus.

1 is a diagram showing a configuration of an image forming apparatus according to the present invention. FIG. 2 is a block diagram showing an electrical configuration of the image forming apparatus in FIG. 1. FIG. 3 is a diagram illustrating an operation in the first embodiment of the image forming apparatus according to the invention. FIG. 10 is a diagram illustrating an operation in the second embodiment of the image forming apparatus according to the present invention. 6 is a flowchart showing first print preparation processing. The flowchart which shows the stirring process in the 1st printing preparation process of FIG. 6 is a flowchart showing patch processing in the first print preparation processing of FIG. 5. FIG. 10 is a diagram illustrating an operation in the third embodiment of the image forming apparatus according to the present invention. FIG. 10 is a diagram illustrating an operation in the fourth embodiment of the image forming apparatus according to the present invention. 10 is a flowchart showing second print preparation processing. 11 is a flowchart showing a stirring process in the second printing preparation process of FIG. 11 is a flowchart showing patch processing in the second print preparation processing of FIG. FIG. 14 is a diagram illustrating an operation in the fifth embodiment of the image forming apparatus according to the invention. The flowchart which shows the interruption process in 5th Embodiment. The figure which shows the progress of the printing preparation operation | movement in a 2nd printing preparation process. 10 is a flowchart showing second print preparation processing. 17 is a flowchart showing patch processing in the second print preparation processing of FIG. The figure which shows operation | movement in 6th Embodiment of the image forming apparatus concerning this invention. 10 is a flowchart showing third print preparation processing. The flowchart which shows the stirring process in the 3rd printing preparation process of FIG. 20 is a flowchart showing patch processing in the third print preparation processing of FIG. 19. The figure which shows the progress of the printing preparation operation | movement in a 3rd printing preparation process. FIG. 10 is a diagram showing printability determination processing in a fifth embodiment. The flowchart which shows the 2nd interruption process in 5th Embodiment. FIG. 16 is a diagram illustrating an operation in the seventh embodiment of the image forming apparatus according to the invention. 10 is a flowchart showing fourth print preparation processing. FIG. 27 is a flowchart showing an agitation process in the fourth print preparation process of FIG. 26. 27 is a flowchart showing patch processing in the fourth print preparation processing of FIG. The figure which shows the progress of the printing preparation operation | movement in a 4th printing preparation process. The figure which shows operation | movement in 8th Embodiment of the image forming apparatus concerning this invention. The figure which shows operation | movement in 9th Embodiment of the image forming apparatus concerning this invention. The figure which shows operation | movement in 10th Embodiment of the image forming apparatus concerning this invention. The figure which shows the printing information determination process in 10th Embodiment. 10 is a flowchart showing fifth print preparation processing. The flowchart which shows the stirring process in the 5th printing preparation process of FIG. 35 is a flowchart showing patch processing in the fifth print preparation processing of FIG. 21 is a flowchart showing the operation of the image forming apparatus according to the eleventh embodiment of the present invention.

Explanation of symbols

  4 ... development unit, 4Ka to 4Kd ... development cartridge, 10 ... engine controller (second control unit), 11 ... main controller (first control unit), 22 ... photosensitive member (latent image carrier), 40 ... support Frame 44. Developing roller (toner carrier)

Claims (15)

A latent image carrier capable of carrying an electrostatic latent image;
A developing unit in which a plurality of cartridges having toner of a specific color are detachably provided;
Control means for selectively positioning a cartridge mounted on the developing unit at a developing position and executing a printing operation for developing an electrostatic latent image on the latent image carrier using toner in the cartridge; Prepared,
The control unit determines printable information on whether or not the printing operation by the cartridge is feasible or not feasible for each cartridge mounted on the developing unit, and the mode according to the judgment result An image forming apparatus that executes a print preparation process that is performed before the execution of the printing operation in order to enable the printing operation by the cartridge.   2. The control unit permits execution of the printing operation when at least one of the cartridges mounted on the developing unit is capable of executing a printing operation by performing the printing preparation process. Image forming apparatus. The control means includes
A first control unit that accepts a print request;
The image forming apparatus according to claim 1, further comprising a second control unit that executes the print preparation process and the printing operation in response to a control command from the first control unit.   If at least one of the cartridges mounted on the developing unit is capable of executing a printing operation when the printing request is input, the first control unit performs the printing operation by the cartridge capable of executing the printing operation. The image forming apparatus according to claim 3, wherein the control command for starting the operation is given to the second control unit.   When the print request is input, if all of the cartridges attached to the developing unit cannot execute the printing operation, the first control unit is attached to the developing unit as the print preparation process. The control command for performing a print preparation operation for the cartridge before the execution of the printing operation only for the priority cartridge, in order to enable a printing operation by the cartridge as a priority cartridge. The image forming apparatus according to claim 3, wherein the second control unit is provided with   When the control command for starting the printing operation is input from the first control unit, if the entire cartridge mounted on the developing unit cannot execute the printing operation, the second control unit As a print preparation process, one of the cartridges mounted in the developing unit is set as a priority cartridge, and a print preparation to be performed on the cartridge before the execution of the print operation to enable the print operation by the cartridge is performed. The image forming apparatus according to claim 3, wherein a print preparation process request signal requesting permission to execute the operation for the priority cartridge is output to the first control unit.   If all of the cartridges attached to the developing unit cannot execute the printing operation, the second control unit may perform the printing operation using the cartridge before the execution of the printing operation as the print preparation process. 4. The image according to claim 3, wherein a print preparation processing request signal for requesting permission to execute a print preparation operation performed on the cartridge for all of the cartridges mounted on the developing unit is output to the first control unit. Forming equipment.   When the control command for instructing the start of the printing operation is input from the first control unit while the printing preparation operation is being executed for all the mounted cartridges, the developing unit If at least one of the cartridges attached to the developing unit can execute a printing operation, or after the control command is input from the first control unit, at least one of the cartridges attached to the developing unit is 8. The image forming apparatus according to claim 7, wherein when the printing operation can be executed, the printing preparation operation is interrupted and the printing operation is started using a cartridge capable of executing the printing operation.   When the print request is input during execution of the print preparation operation for all the mounted cartridges, the first control unit executes the print operation of at least one of the cartridges mounted on the developing unit. If possible, or if at least one of the cartridges attached to the developing unit can execute a printing operation after the print request is input to the first control unit, the print preparation operation is interrupted. The control command for instructing the printing operation is supplied to the second control unit, and after confirming the interruption of the printing preparation operation, the control command for starting the printing operation using a cartridge capable of executing the printing operation is provided. 8. The image forming apparatus according to claim 7, which is given to the control unit.   The second control unit can execute the print operation by performing the print preparation operation on one of the mounted cartridges while the print preparation operation is being performed on all the installed cartridges. Each time, it is confirmed whether or not the control command instructing the start of the printing operation is input from the first control unit, and if the control command is input, the printing preparation operation is interrupted, The image forming apparatus according to claim 7, wherein the printing operation is started.   11. The image forming apparatus according to claim 8, wherein after the completion of the printing operation is confirmed, the printing preparation operation is executed for the remaining mounted cartridges that are not subjected to the printing preparation operation.   Based on the printable information and the print request, the first control unit selects a cartridge that should be able to execute a print operation from a cartridge mounted on the developing unit as a selected cartridge, and uses the cartridge as the print preparation process. 4. The image according to claim 3, wherein the control command for performing a print preparation operation for the cartridge before the execution of the print operation to enable the print operation only for the selected cartridge is given to the second control unit. 5. Forming equipment.   The first control unit is configured to be able to select a plurality of different print preparation processes, and selects one print preparation process from the plurality of print preparation processes based on the printable information and the print request The image forming apparatus according to claim 3, wherein the control command for executing the first print preparation process is given to the second control unit.   The image forming apparatus according to claim 1, wherein M (M ≧ 2) cartridges are attached to the developing unit. A latent image carrier capable of carrying an electrostatic latent image; and a developing unit in which a plurality of cartridges having toner of a specific color are detachably provided, and the cartridge attached to the developing unit is selectively developed at a developing position. In the image forming method of executing the printing operation of developing the electrostatic latent image on the latent image carrier using the toner in the cartridge,
For each cartridge installed in the developing unit, printable information is determined as to whether the printing operation by the cartridge is feasible or not, and printing according to the judgment result is performed. An image forming method comprising: performing a print preparation process that is performed before execution of the printing operation in order to enable the operation.

Images