JP2024002138A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus such as a MFP that can change fixing control of a fuser according to the paper length, paper width, and paper thickness of a sheet actually placed on a manual feed tray, thereby fixing an image to any type of sheet that can be fed in the image forming apparatus.SOLUTION: The present invention comprises: a manual feed tray; a printing unit that executes printing on a sheet fed from the manual feed tray; a fuser that fixes the image on the sheet printed by the printing unit; a measuring unit that measures at least one of the paper width and paper thickness of the sheet while the sheet is fed from the manual feed tray; and a fixing control unit that, when a manual free mode is selected which is for performing printing on the sheet even when a paper size set in paper settings of an image forming apparatus and the paper size of the sheet placed on the manual feed tray are different from each other, changes fixing control of the fuser based on a result of measurement of at least one of the paper width and paper thickness performed by the measuring unit.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image forming apparatus.

A technology (manual feed free mode) has been developed that allows manual printing to be performed even if the paper size set in the machine's paper settings differs from the paper size actually set in the manual feed tray. Patent Document 1 discloses a configuration in which the paper thickness is measured near a registration stop position for the purpose of automatically setting the paper thickness of the paper actually set by the user.

However, in the manual feed free mode, only the paper length is measured when actually feeding the paper set in the manual feed tray, so if long and narrow paper is set in the manual feed tray, the fusing unit (an example of a fuser) The temperature of the end portions increases, which may cause damage to the fixing unit or offset due to excessive heat at the end portions of the fixing unit during the next printing.

The present invention has been made in view of the above, and is capable of forming images on an MFP, etc. by changing the fixing control of a fixing device according to the paper length, paper width, and paper thickness of the paper actually set in the manual feed tray. An object of the present invention is to provide an image forming apparatus that can handle all types of paper that can be passed through the apparatus.

In order to solve the above problems and achieve the objects, the present invention provides a manual feed tray, a printing unit that prints on paper fed from the manual feed tray, and an image printed on the paper by the printing unit. a measuring unit that measures at least one of paper width and paper thickness of the paper when feeding paper from the manual feed tray; and a paper size set in the paper settings of the image forming apparatus; When the manual feed free mode is selected in which printing is performed on paper even if the paper size of the set paper is different, the fixing device A fixing control unit that changes fixing control.

According to the present invention, the fixing control of the fixing device is changed according to the paper length, paper width, and paper thickness of the paper actually set in the manual feed tray, so that it can be applied to any paper that can be passed through an image forming apparatus such as an MFP. This has the effect of being able to respond accordingly.

FIG. 1 is a diagram showing an example of the appearance of a full-color digital copying machine according to this embodiment. FIG. 2 is a diagram showing an example of the mechanism of the color printer according to this embodiment. FIG. 3 is an enlarged view of an example of the cassette of the full-color digital copying machine according to the present embodiment. FIG. 4 is a diagram showing an example of a system configuration of a full-color digital copying machine according to this embodiment. FIG. 5 is a flowchart showing an example of the flow of print processing of the laser printer according to the present embodiment.

Embodiments of an image forming apparatus will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a diagram showing an example of the appearance of a full-color digital copying machine according to this embodiment. The full-color digital copying machine according to this embodiment is an example of an image forming apparatus that can print on paper fed from a manual tray. Further, the full-color digital copying machine according to this embodiment is an example of an image forming apparatus in which a manual feed free mode can be selected. Here, the manual feed free mode is a mode in which printing is performed on paper even if the paper size set in the paper settings of the full-color digital copying machine and the paper size of the paper set in the manual feed tray 37 are different.

This full-color digital copying machine roughly consists of an automatic document feeder (ADF) 30, an operation board 20, a color document scanner 10, a color printer (laser printer) 100, and a paper feed bank 35. It has a unit. Further, a finisher 34 with a stapler and a tray on which images have been formed can be loaded, a duplex drive unit 33, and a large-capacity paper feed tray 36 are installed in the color printer 100.

A system controller 630 (see FIG. 4) in the full-color digital copying machine is connected to a LAN (Local Area Network) to which a PC is connected. The printed paper of the color printer 100 is discharged onto the paper discharge tray 108 or to the finisher 34.

FIG. 2 is a diagram showing an example of the mechanism of the color printer according to this embodiment. Color printer 100 is a laser printer. In this color printer 100, four sets of toner image forming units for forming images of magenta (M), cyan (C), yellow (Y), and black (black: K) move the transfer paper. They are arranged in this order along the direction (from the lower right to the upper left direction y in the figure). That is, it is a four-drum full-color image forming apparatus. In this embodiment, the toner image forming unit functions as an example of a printing unit that prints on paper fed from the manual feed tray 37.

These magenta (M), cyan (C), yellow (Y), and black (K) toner image forming units are photoreceptor units 110M, 110C, and 110Y having photoreceptor drums 111M, 111C, 111Y, and 111K, respectively. , 110K, and developing units 120M, 120C, 120Y, and 120K. In addition, the arrangement of each toner image forming section is such that the rotation axes of the photoconductor drums 111M, 111C, 111Y, and 111K in each photoconductor unit are parallel to the horizontal x-axis (main scanning direction), and the transfer paper They are set to be arranged at a predetermined pitch in the moving direction y (sub-scanning direction).

In addition to the toner image forming unit described above, the laser printer 100 also carries an optical writing unit 102 by laser scanning, cassettes 103 and 104, a pair of registration rollers 105, and a transfer paper that passes through the transfer position of each toner image forming section. The image forming apparatus includes a transfer belt unit 106 having a transfer conveyance belt 160 for conveying the image so as to convey the image, a fixing unit 107 using a belt fixing method, a paper discharge tray 108, a double-sided drive (face reversal) unit 33, and the like. The laser printer 100 also includes a manual feed tray 37, a toner supply container, a waste toner bottle, and the like.

Here, the manual feed tray 37 has a measuring section 37a that measures at least one of the paper width and paper thickness of the paper when the paper is fed from the manual feed tray 37. The measurement unit 37a may be, for example, a reflective optical sensor. Further, the measuring unit 37a can also measure the length of the paper being fed from the manual tray 37.

The optical writing unit 102 includes a light source, a polygon mirror, an f-theta lens, a reflection mirror, etc., and emits a laser beam in the x direction on the surface of each photoreceptor drum 111M, 111C, 111Y, 111K based on image data. Irradiates while scanning. Further, the dashed line in FIG. 2 indicates the transport path of the transfer paper. The transfer paper fed from the cassettes 103 and 104 is conveyed by a conveyance roller while being guided by a conveyance guide, and is sent to a pair of registration rollers 105. The transfer paper sent to the transfer conveyance belt 160 at a predetermined timing by the pair of registration rollers 105 is carried by the transfer conveyance belt 160 and conveyed so as to pass through the transfer position of each toner image forming section.

The toner images formed on the photoreceptor drums 111M, 111C, 111Y, and 111K of each toner image forming section are transferred to the transfer paper carried and conveyed by the transfer conveyance belt 160, and the toner images of each color are superimposed, that is, a color image is created. The formed transfer paper is sent to the fixing unit 107. That is, the transfer is a direct transfer method in which a toner image is directly transferred onto transfer paper. When passing through the fixing unit 107, the toner image is fixed on the transfer paper. That is, the fixing unit 107 is an example of a fixing device that fixes an image on paper. In this embodiment, the fixing unit 107 includes a heater, and fixes the image on the paper by turning on the heater to heat a medium such as paper. The transfer paper with the toner image fixed thereon is discharged or fed to the paper discharge tray 108, the finisher, or the duplex drive unit 33.

An overview of the yellow Y toner image forming unit will be described below. The other toner image forming units also have the same structure as that of yellow Y. The yellow Y toner image forming unit includes the photoreceptor unit 110Y and the developing unit 120Y, as described above. In addition to the photoreceptor drum 111Y, the photoreceptor unit 110Y includes a brush roller that applies lubricant to the photoreceptor drum surface, a swingable blade that cleans the photoreceptor drum surface, and a static elimination lamp that irradiates the photoreceptor drum surface with light. , a non-contact charging roller that uniformly charges the surface of the photoreceptor drum, and the like.

In the photoconductor unit 110Y, a laser beam modulated based on print data and deflected by a polygon mirror is applied to the surface of the photoconductor drum 111Y, which is uniformly charged by a charging roller to which an AC voltage is applied, by an optical writing unit 102. When L is irradiated while being scanned, an electrostatic latent image is formed on the surface of the photoreceptor drum 111Y. The electrostatic latent image on the photoreceptor drum 111Y is developed into a yellow Y toner image by the developing unit 120Y. At the transfer position where the transfer paper on the transfer conveyance belt 160 passes, the toner image on the photosensitive drum 111Y is transferred to the transfer paper. After the toner image has been transferred, the surface of the photosensitive drum 111Y is coated with a predetermined amount of lubricant using a brush roller, then cleaned with a blade, and is neutralized by light irradiated from a static elimination lamp. Provided for the formation of a latent image.

The developing unit 120Y stores a two-component developer containing a magnetic carrier and negatively charged toner. The developing unit 120Y includes a developing roller, a conveying screw, a doctor blade, a toner concentration sensor, a powder pump, etc., which are disposed so as to be partially exposed from the opening on the photosensitive drum side of the developing unit 120Y. The developer housed in the developing case is triboelectrically charged as it is stirred and conveyed by the conveyance screw. A portion of the developer is carried on the surface of the developing roller. The doctor blade uniformly regulates the layer thickness of the developer on the surface of the developing roller, and the toner in the developer on the surface of the developing roller is transferred to the photoreceptor drum, whereby a toner image corresponding to the electrostatic latent image is transferred to the photoreceptor. It appears on the drum 111Y. The toner concentration of the developer in the developing case is detected by a toner concentration sensor. When the toner density is insufficient, the powder pump is driven to replenish toner.

The transfer conveyance belt 160 of the transfer belt unit 106 is hung on four grounded tension rollers so as to pass through each transfer position that contacts and faces the photoreceptor drums 111M, 111C, 111Y, and 111K of each toner image forming section. It's being passed around. One of the tension rollers is 109. Among these tension rollers, an electrostatic adsorption roller to which a predetermined voltage is applied from a power source is disposed so as to face an entrance roller on the upstream side in the direction of movement of the transfer sheet, which is indicated by a two-dot chain arrow. The transfer paper that has passed between these two rollers is electrostatically attracted onto the transfer conveyance belt 160. Further, the exit roller on the downstream side in the transfer paper movement direction is a drive roller that frictionally drives the transfer conveyance belt, and is connected to a drive source. Further, a bias roller to which a predetermined cleaning voltage is applied from a power source is arranged so as to be in contact with the outer peripheral surface of the transfer conveyance belt 160. Foreign matter such as toner adhering to the transfer conveyance belt 160 is removed by this bias roller.

Further, a transfer bias applying member is provided so as to come into contact with the back surface of the transfer conveyance belt 160 forming a contact facing portion that contacts and faces the photoreceptor drums 111M, 111C, 111Y, and 111K. These transfer bias applying members are fixed brushes made of Mylar, and a transfer bias is applied from each transfer bias power source. The transfer bias applied by the transfer bias applying member applies a transfer charge to the transfer conveyance belt 160, and a transfer electric field of a predetermined intensity is formed between the transfer conveyance belt 160 and the surface of the photoreceptor drum at each transfer position. .

The paper is conveyed by the transfer conveyance belt 160, and the toner images of each color formed on the photoreceptor drums 111M, 111C, 111Y, and 111K are transferred to the fixing unit 107, where the toner images are heated and pressed. It is thermally fixed to the paper. After the thermal fixation, the paper is sent to the finisher 34 from the paper discharge port for the finisher 34 in the upper part of the left side plate. Alternatively, the paper is ejected to the paper ejection tray 108 on the top surface of the printer main body.

Paper sensors 112, 113, 114, and 115, which are reflective optical sensors, are arranged in front of the registration roller 105 and in the gaps between the arrays of the image forming units for each color. There is a touch-type paper sensor 116 that is a combination of a microswitch and a microswitch. Paper sensors 113 to 115 that detect sheets of paper with toner transfer are placed at positions that detect margin portions of the paper without toner transfer.

FIG. 3 is an enlarged view of an example of the cassette of the full-color digital copying machine according to the present embodiment. The paper bundle 117 rests on a middle plate, and when it is attached to the main body of the laser printer 100, the middle plate is pushed up and the leading edge of the paper in the paper passing direction is pressed by a separating claw 118 on the side of the cassette. When the paper is fed in the paper passing direction by the feeding roller, the separation claw 118 separates and feeds only the topmost paper from the stack of papers below. After setting the paper bundle 117 in the cassette, the user sets the size by turning the paper size setting dial 119 to a position corresponding to the set paper size.

The back side of the paper size setting dial 119 has a groove and a hole for selectively receiving an operating pin 122 of an angle responsive switch 121 provided in the printer body. The angle response switch 121 has four built-in microswitches, and each of the microswitches is turned on using each of the four working pins 122. By inserting the cassette 103 into the laser printer 100 in the cassette insertion direction, one or more working pins 122 are set on the paper size setting dial 119 in accordance with the rotation angle (each size specified position) of the paper size setting dial 119. It is pressed on the back side and moves backwards to turn the corresponding micro switch from off to on. As a result, the angle responsive switch 121 generates 4-bit paper size data. When the cassette 103 is removed from the installed position of the laser printer 100, all of the working pins 122 of the angle response switch 121 are protruded, all four microswitches are off, and the 4-bit paper size data is It is "0000" which represents the numerical value 0, which means that there is no cassette.

According to the setting position of the paper size setting dial 119, when set to the "Postcard Landscape" position, the paper size data becomes "0001" representing the number 1, and when set to the "A5 Landscape" position, the paper size data becomes "0010" representing the number 2. So, when set to the "B5 landscape" position, the paper size data becomes "0011" representing the number 3, and when set to the "A4 portrait" position, the paper size data becomes "0100" representing the number 4, and so on. When set at a position representing a standard size, the data becomes data representing the standard size.

Although the cassette 104 is larger than the cassette 103, the paper feeding mechanism and paper size setting mechanism are the same as those of the cassette 103, and the printer body has a paper size setting dial that indicates the setting size of the paper size setting dial of the cassette 104. It is equipped with an angle-responsive switch that generates data.

Referring again to FIG. 1, the finisher 34 has a stacker tray, that is, a stacking descending tray 34hs and a sorting tray group 34st, and a stacker paper ejecting unit that discharges paper (printed paper, transferred paper) to the stacking descending tray 34hs. mode, and a sorter paper discharge mode in which paper is discharged to the sort tray group 34st.

The paper sent from the laser printer 100 to the finisher 34 is conveyed in the upper left direction, passes through an upside-down U-shaped conveyance path, changes the conveyance direction downward, and then, depending on the set mode, In the stacker discharge mode, the sheets are discharged from the discharge port onto the stacking descending tray 34hs. In the sorter paper ejection mode, the paper currently being ejected from the sort tray group 34st is ejected to the assigned sorter tray.

When the sorter paper ejection mode is specified, the finisher paper ejection controller drives the sort tray group 34st placed at the lowest stacking retreat position upward to the use position shown by the two-dot chain line in FIG. Increase the distance between. In the sorter paper discharge mode, when copying or printing the set number of sheets at one time (for one person), when the sorter paper discharge mode is set for copy sorting, each transfer paper on which the same original (image) is printed is transferred to the sort tray group 34st. Sort and store in each tray. When the sorter discharge mode is set for page sorting, each tray is assigned to each page (image), and each transfer sheet on which the same page is printed is stacked on one sorting tray.

FIG. 4 is a diagram showing an example of a system configuration of a full-color digital copying machine according to this embodiment. A reading unit 11 of the color document scanner 10 that optically reads a document scans the document with a lamp, and forms a document image on a CCD of an SBU (sensor board unit). The original image, that is, the reflected light from the irradiation on the original, is photoelectrically converted by a CCD to generate R, G, and B image signals, which are converted to RGB image data and shading corrected on the SBU, and output I/F (interface ) 12, the data is sent to an image data processor (IPP) (hereinafter simply referred to as IPP) via the image data bus.

IPP performs separation generation (determining whether an image is a text area or a photo area: image area separation), background removal, scanner gamma conversion, filters, color correction, scaling, image processing, printer gamma conversion, and gradation processing. . IPP is a programmable arithmetic processing means that performs image processing. The image data transferred from the color original scanner 10 to the IPP is corrected for signal deterioration (signal deterioration in the scanner system) caused by the optical system and quantization into digital signals at the IPP, and is written into the frame memory 601.

The system controller 630 has functions of multiple applications such as a scanner application, a facsimile application, a printer application, and a copy application, and controls the entire system. The operation panel control device of the operation board 20 is a device that decodes input from the operation board 20 and displays the settings of this system and its status contents. The image data bus or control command bus is a bus on which image data and control commands are transferred in a time-division manner.

The CPU 605 of the system controller 630 controls the system controller 630. A control program for the system controller 630 is written in the ROM 604. RAM 603 is a working memory used by CPU 605. The NVRAM 602 is a non-volatile memory, and stores information about the entire system, such as sub-scanning magnification adjustment values and main-scanning magnification adjustment values.

The external device communication control unit 606 controls communication with external devices that request image reading, image storage, or image printing (for example, a similar type of copier, image scanner, personal computer, server, printer, facsimile). , controls the physical I/F for connecting to the network. When the network-connected external device communication control unit 606 receives data from the network, it sends only the contents of the communication data to the system I/F 607 using an electrical signal. The system I/F 607 logically converts the received data according to a specified protocol and sends it to the CPU 605. The CPU 605 judges and processes the logically converted received data. Furthermore, when the CPU 605 transmits data to the network, the transmission data is transmitted to the system I/F 607 and the external device communication control unit 606 in the reverse procedure of reception, and is sent out on the network as an electrical signal.

The system I/F 607 controls the transfer of document reading data, facsimile reception data, document data (print commands; drawing information) from a PC or server, which are processed within the system according to instructions from the CPU 605, information) to print image data (image data) and transfer it. The work memory 600 is a work memory for image development (conversion from document data to image data) used in a printer. The frame memory 601 is a working memory that temporarily stores image data of read images and written images that are immediately printed while power continues to be supplied.

The HDDC 650 is a hard disk and its controller that can store image data of read or written images, that is, image data and document data even if the power supply is stopped. Image data and document data may be encoded or dot images. The FIFO buffer memory 609 performs data transfer rate conversion when writing an input image to the frame memory 601. In other words, data is temporarily stored to absorb differences in data sending or receiving timing between the transfer source and the transfer destination, differences in the amount of data in transfer units, differences in transfer speed, etc., and data is accepted at the transfer timing and speed of the transfer source. Send data at the transfer timing and speed of the transfer destination. Similarly, the FIFO buffer memory 608 performs speed conversion when transferring image data in the frame memory 601 as an output image.

The memory controller 610 controls image input/output between the frame memory 601 and the HDDC 650 and the bus. Furthermore, in response to commands received by the input device 614 of the operation board 301, the frame memory 601 is used to edit and process images stored in the HDDC 650. The memory controller 610 reads image information from the HDD of the HDDC 650 to the work memory 600 or the frame memory 601, changes the printing direction of the image on transfer paper, rotates the image, and edits the combination of images mainly by changing the image data address. Various types of processing are possible by performing density conversion by adding, subtracting, multiplying and dividing setting values for image data, image trimming and compositing by logical product and logical sum operations between image data, and writing the thus processed image information to the HDD. Image processing and editing can be performed.

The memory controller 610 further processes the document data (drawing information) received by the external device communication control unit 606 and written into the work memory 600 under the control of the CPU 605 in accordance with the control of the CPU 605 to develop the document data into dot image data. , converted into CMYK image data used by the color printer 100 and developed in the frame memory 601. An expansion processing program for this purpose is installed on the HDD.

The CPU 617 performs input/output control of the operation board 20. That is, it controls input reading and display output of the operation board 20. A control program for the operation board 20 is written in the ROM 616. RAM 618 is a working memory used by CPU 617. The input device 614 is an input device through which the user inputs system settings by operating the input keys and input panel of the operation board 20. The display device 615 is located on the operation board 20 and displays the settings and status of the system to the user, and includes an indicator light and a display panel. The basic magnification adjustment values for main scanning and sub-scanning are determined by measuring the magnification using sample images in the system adjustment process, and are set by the operation panel control device. In addition, the four edgeless magnification adjustment values for main scanning and sub-scanning are determined by the user or maintenance personnel checking the printed image for image defects and margins, and adjusting the magnification adjustment values to suppress them from the operation board. 20.

The color printer 100 includes a write I/F 134 that receives CMYK image data from a system controller 630, an image forming unit 135 that prints an image on paper according to the CMYK image data, and a process controller 131. The image forming unit 135 includes a toner image forming section, a fixing unit 107, and the like. The process controller 131 of the color printer 100 includes a ROM that stores a copying machine control program, a RAM that stores data used by the control program, and a RAM that stores adjustment values, jam data, etc. even after the power is turned off. A backup power source (battery) for the RAM, a CPU that reads the control program from the ROM and executes the command, a reset circuit that outputs a reset signal for a certain period of time to the CPU when the power is turned on and operates the CPU from the beginning of the control program, and a copy. A plurality of timers and the like are provided to generate timings for each control of the machine.

The process controller 131 receives various inputs from various sensors, SWs, thermistors, etc. for determining the status of the copying machine, as well as various motors, various SLs (solenoids), various CLs ( There is an input/output interface (input/output electrical circuit) that generates output signals to the clutch), heater, lamp, etc. An angle responsive switch and paper sensors 112-116 are connected to an input interface of process controller 131.

The CPU of the process controller 131 performs image formation control, that is, process control, in accordance with image formation commands from the system controller 630 in accordance with input from the operation board 20 or input from the PC.

Further, the process controller 131 is an example of a fixing control unit that changes the fixing control of the fixing unit 107 based on the measurement result of at least one of paper width and paper thickness by the measuring unit 37a when the manual feed free mode is selected. . Specifically, when the manual feed free mode is selected, the process controller 131 changes the fixing control of the fixing unit 107 to a fixing control that allows printing regardless of paper width and paper thickness set in the manual feed tray 37. change. Here, fixing control that allows printing regardless of paper width and paper thickness set in the manual feed tray 37 refers to the minimum or maximum paper width that can be printed on the laser printer 100 and the thinnest paper that can be printed on the laser printer 100. Also includes fixing control that allows printing even with the thickest paper thickness combination.

In other words, even if manual feed free mode is selected and paper is fed with a paper width or thickness different from the paper size set in the paper settings of the full-color digital copier, the process controller 131 adjusts the paper feed according to the paper size. The fixing control of the fixing unit 107 is changed. This can prevent the temperature of the end of the fixing unit 107 from rising, and can prevent damage to the fixing unit 107 and occurrence of offset due to an excessive amount of heat at the end of the fixing unit 107 during the next printing. As a result, it is possible to handle all types of paper that can be passed through a full-color digital copying machine.

In this embodiment, the fixing control of the fixing unit 107 includes at least one of controlling the target temperature of the fixing unit 107 and controlling the lighting time of the fixing unit 107. Furthermore, if the measurement of the paper length by the measuring unit 37a of the manual feed tray 37 has not been completed, the process controller 131 changes the fixing control of the fixing unit 107 based on the longest paper length that can be printed by the color digital copying machine. do. Further, when the measuring unit 37a of the manual tray 37 completes measuring the paper length, the process controller 131 changes the fixing control of the fixing unit 107 based on the measured paper length.

Furthermore, in the present embodiment, the process controller 131 is configured based on the combination of paper width and paper length measured by the measurement unit 37a of the manual feed tray 37, or the combination of paper thickness and paper length measured by the measurement unit 37a. It is also possible to change the fixing control of the fixing unit 107.

FIG. 5 is a flowchart showing an example of the flow of print processing of the laser printer according to the present embodiment. When starting printing in the manual feed free mode, the laser printer 100 performs a sheet feeding operation from the manual feed tray 37 (step S501). In this embodiment, the user can operate the operation board 20 to specify whether the manual feed free mode function is turned on or off.

Next, the measuring section 37a of the manual tray 37 measures the thickness and width of the paper fed from the manual tray 37. Then, the process controller 131 determines whether the paper thickness and paper width set in the paper settings of the machine are equal to the paper thickness and paper width measured by the measuring section 37a (step S502). Here, the fact that the paper thickness and paper width set in the paper settings are equal to the measured paper thickness and paper width means that the measured paper thickness and paper width are and that the paper width is within a preset range.

If the paper thickness and paper width set in the paper settings are equal to the paper thickness and paper width measured by the measuring unit 37a (step S502: Yes), the process controller 131 proceeds to step S504. On the other hand, if there is a difference between the paper thickness and paper width set in the paper settings and the paper thickness and paper width measured by the measuring unit 37a (step S502: No), the process controller 131 controls the fixing control of the fixing unit 107. is changed to fixing control such as fixing temperature control and heater lighting control that are optimized based on the paper thickness and paper width measured by the measurement unit 37a (step S503).

Next, the process controller 131 determines whether the actual value of the paper length of the fed paper (the paper length measured by the measuring unit 37a) is equal to the paper length set in the paper settings of the machine. (Step S504). Here, the actual value of the paper length is equal to the paper length set in the paper settings means that the actual value of the paper length is within the preset range based on the paper length set in the paper settings. Including something.

If the actual value of the paper length is equal to the paper length set in the paper settings (step S504: Yes), the process controller 131 continues printing on the paper, ejects the paper, and ends the printing process. . On the other hand, if the actual value of the paper length is longer than the paper length set in the paper settings (step S504: No), the process controller 131 controls the fixing control of the fixing unit 107 to the longest paper length that can be passed by the laser printer 100. The fixing control is changed to fixing temperature control and heat lighting control based on the paper length (step S505).

After that, when the paper length of the paper fed to the manual feed tray 37 is determined, the process controller 131 changes the fixing control of the fixing unit 107 to the fixing control optimized for the determined paper length (step S506). After that, the process controller 131 discharges the printed paper and ends the printing process.

As described above, according to the full-color digital copying machine according to the present embodiment, it is possible to prevent the end portion of the fixing unit 107 from rising in temperature, and prevent damage to the fixing unit 107 and the end portion of the fixing unit 107 during the next printing. It is possible to prevent offset, etc. from occurring due to an excessive amount of heat. As a result, it is possible to handle all types of paper that can be passed through a full-color digital copying machine.

In the above embodiment, an example will be described in which the image forming apparatus of the present invention is applied to a multifunction device having at least two functions among a copy function, a printer function, a scanner function, and a facsimile function. The present invention can be applied to any image forming apparatus such as a printer, a scanner device, a facsimile device, or the like.

37 Manual feed tray 37a Measuring section 100 Laser printer 107 Fixing unit 131 Process controller 135 Image forming unit

Japanese Patent Application Publication No. 2017-211634

Claims (5)

manual feed tray,
a printing unit that prints on paper fed from the manual feed tray;
a fixing device that fixes the image printed on the paper by the printing unit;
a measuring unit that measures at least one of paper width and paper thickness of paper when feeding paper from the manual feed tray;
If the manual feed free mode is selected in which printing is performed on paper even if the paper size set in the image forming device's paper settings and the paper size of the paper set in the manual feed tray are different, the measurement unit a fixing control unit that changes fixing control of the fixing device based on a measurement result of at least one of paper width and paper thickness;
An image forming apparatus comprising: When the manual feed free mode is selected, the fixing control unit controls the fixing of the fixing device based on the measurement results so that printing is possible no matter what paper width and paper thickness paper is set in the manual feed tray. The image forming apparatus according to claim 1, wherein the image forming apparatus changes to a fixing control. The image forming apparatus according to claim 1 , wherein the fixing control of the fixing device includes at least one of controlling a target temperature of the fixing device and controlling a lighting time of a heater included in the fixing device. The measuring unit further measures the paper length of the paper while feeding the paper from the manual feed tray,
If the measurement of the sheet length by the measuring section is not completed, the fixing control section changes the fixing control of the fixing device based on the longest sheet length printable by the image forming apparatus, and controls the measuring section. The image forming apparatus according to claim 1 , wherein when the measurement of the paper length is completed, fixing control of the fixing device is changed based on the measured paper length. The fixing control unit changes the fixing control of the fixing device based on a combination of paper width and paper length measured by the measurement unit, or a combination of paper thickness and paper length measured by the measurement unit. Item 4. The image forming apparatus according to item 4.

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