JP5170142B2 - Image forming apparatus and developing cartridge - Google Patents

Description

  The present invention relates to an image forming apparatus and a developing cartridge configured to be easily attached to and detached from a main body portion in the image forming apparatus.

  As this type of apparatus, for example, those disclosed in Japanese Patent Application Laid-Open No. 2000-221781, Japanese Patent Application Laid-Open No. 2006-243073, Japanese Patent Application Laid-Open No. 2006-267994, and the like are known. These apparatuses are provided with a new article detecting means for detecting whether or not the mounted developing cartridge is new. By detecting the installation of a new developing cartridge by the new article detecting means, it is possible to determine the life of the developing cartridge since the new article was detected.

  In this type of apparatus, it is necessary to acquire various pieces of information other than whether or not the mounted developing cartridge is new. The present invention has been made to cope with such a problem.

<Configuration>
The image forming apparatus of the present invention includes a main body portion and a replaceable developing cartridge that is configured to be easily attached to and detached from the main body portion. The image forming apparatus may further include a developer remaining amount detecting unit that detects the remaining amount of the developer accommodated in the developing cartridge.

  The developing cartridge of the present invention is configured to be easily attached to and detached from the main body. For example, the developing cartridge includes a casing, a developer carrying roller, and a developer supply roller. The casing is a box-shaped member, and is configured to store the developer in a developer storage portion which is a space inside the casing. The developer carrying roller is rotatably supported by the casing, and is configured to carry a thin layer of the developer on a smooth cylindrical surface. The developer supply roller is rotatably supported by the casing. The developer supply roller faces the developer accommodating portion and contacts the peripheral surface in order to carry the developer accommodated in the developer accommodating portion on the peripheral surface of the developer carrying roller. As described above, it is disposed between the developer accommodating portion and the developer carrying roller.

  The main body is provided with driving means for transmitting a driving force for an image forming operation to the developing cartridge. Correspondingly, a driven member is provided in the developing cartridge. The driven member is configured to be driven by a limited predetermined driving range only when the driving force is transmitted from the driving means for the first time after the mounting operation to the main body. More specifically, the driven member is provided only when the driving force is first transmitted from the driving unit after the developing cartridge in the “initialized” state is mounted on the main body. While being driven only within a predetermined drive range, it is configured such that it cannot be driven when the developing cartridge that has not been "initialized" is mounted on the main body. Here, the developing cartridge in the “initialized state” includes, in addition to a new one, a used one restored to a state similar to a new one (for example, a refilled developer). .

  In addition, a moving member is fixed to the driven member in the developing cartridge so as to move as the driven member is driven. Such a moving member is provided corresponding to information relating to the developing cartridge. Correspondingly, the image forming apparatus includes a detection unit and a cartridge information determination unit. The detection means includes an actuator provided so as to be able to come into contact with the moving member, and determines a contact level generated when the moving member contacts the actuator and a non-contact level generated when the moving member does not contact. It is configured to generate a detection signal including. The cartridge information determination means determines the information based on the occurrence state of the contact level and the non-contact level in the detection signal.

  The present invention is characterized in that, in addition to the first moving member serving as the moving member corresponding to whether or not the developing cartridge is in an initialized state being provided in the driven member, The second moving member corresponding to the non-capacity information can be provided as the other moving member (the first moving member is driven by the driven cartridge for initialization determination of the developing cartridge). Although it is always provided in the member, the other moving members can be appropriately provided according to the other information.

  Here, the non-capacity information is the information different from the capacity information. This capacity information is information relating to the amount of developer contained in the developer cartridge or the maximum number of recording media on which an image can be formed according to the amount of developer. For example, the second moving member may be provided corresponding to information regarding characteristics of a roller-like member (such as the developer supply roller) that is rotationally driven during the image forming operation as the non-capacity information. The driven member may be configured such that a third moving member as another moving member corresponding to the capacity information can be provided.

  The second moving member may be provided so as to always contact the actuator in a state where the driven member is driven by the predetermined driving range. Further, when the plurality of moving members are provided at different positions in the predetermined driving range, the first moving member is first applied to the actuator while the driven member is driven by the predetermined driving range. It can be provided so as to abut and pass through the detection means.

<Action and effect>
In this configuration, when the developing cartridge is mounted on the main body portion of the image forming apparatus, the developing cartridge is initialized depending on whether the first moving member is detected by the detecting unit. Is determined (initialization determination). In addition, the second moving member is provided on the driven member according to the non-capacity information, so that the non-capacity information is determined depending on whether or not the second moving member is detected by the detecting means. . In addition, when the third moving member is provided on the driven member according to the capacity information, the capacity information is determined depending on whether or not the third moving member is detected by the detecting means.

  As described above, according to the configuration of the present invention, it is possible to acquire various pieces of information other than whether or not the developing cartridge mounted on the main body is new.

  When the second moving member is provided so that the driven member is always in contact with the actuator while being driven by the predetermined driving range, the developing cartridge is mounted on the main body of the image forming apparatus. The developer cartridge is not in a state of being "initialized" in the main body after being removed from the main body for some reason after being used to some extent The non-capacity information can be reacquired satisfactorily depending on the presence or absence of the second moving member.

  In addition, when the developer remaining amount detecting means is provided, the life of the developer cartridge can be determined more reliably. Specifically, for example, based on the non-capacity information based on the presence / absence of the second moving member, the remaining amount detection condition of the developer by the developer remaining amount detecting means is changed or corrected, so that the remaining amount is detected. The certainty of quantity detection can be improved. Thereby, the determination result of the capacity information by the third moving member can be favorably supplemented.

1 is a side view showing a schematic configuration of a laser printer as an image forming apparatus according to an embodiment of the present invention. FIG. 2 is an enlarged side view of the periphery of a toner case in the process cartridge shown in FIG. 1. FIG. 3 is a partially exploded side view of the process cartridge (toner case) shown in FIG. 2. It is a figure which shows the mode of operation | movement of the detection gear and information detection part which are shown by FIG.2 and FIG.3. It is a figure which shows the mode of operation | movement of the detection gear and information detection part which are shown by FIG.2 and FIG.3. It is a figure which shows the mode of operation | movement of the detection gear and information detection part which are shown by FIG.2 and FIG.3. It is a figure which shows the mode of operation | movement of the detection gear and information detection part which are shown by FIG.2 and FIG.3. It is a figure which shows the mode of operation | movement of the detection gear and information detection part which are shown by FIG.2 and FIG.3. It is a figure which shows the mode of operation | movement of the detection gear and information detection part which are shown by FIG.2 and FIG.3.

<Schematic configuration of laser printer>
FIG. 1 is a side sectional view showing a schematic configuration of a laser printer 1 as an image forming apparatus according to an embodiment of the present invention. The laser printer 1 transports a sheet, which is a sheet-like recording medium, along a paper transport path PP (paper path) inside the laser printer 1 and develops an image (hereinafter, “toner”) on the paper. The toner image is referred to as “toner image”. Specifically, the laser printer 1 includes a paper transport unit 2, a process cartridge 3, a scanner unit 4, a toner remaining amount sensor 5, and a fixing unit 6.

  In the following description, a direction in which a sheet is conveyed along the sheet conveyance path PP in FIG. 1 (that is, a tangential direction at an arbitrary position on the sheet conveyance path PP) is referred to as a “sheet conveyance direction”. Further, the right side in the figure is referred to as “front side”, and the left side in the figure is referred to as “rear side”. Therefore, the left-right direction in FIG. 1 is the front-rear direction of the laser printer 1. Furthermore, the width direction of the laser printer 1 that is perpendicular to the left-right direction (the above-described front-rear direction) and the up-down direction (the height direction of the laser printer 1) in FIG. 1 is referred to as a “paper width direction”. The paper width direction is a direction perpendicular to the paper transport direction and the paper thickness direction.

  The main body 10 includes a main body frame 10 a for supporting the paper transport unit 2, the process cartridge 3, the scanner unit 4, the toner remaining amount sensor 5, and the fixing unit 6. The outer cover 11 is a box-shaped member made of a synthetic resin that constitutes the casing of the main body 10 and is provided so as to cover the main body frame 10a.

  The top cover 12 constituting the top plate of the outer cover 11 is provided with a recess having a shape that becomes deeper toward the rear side. The paper discharge tray 12a is formed by the bottom surface of this recess. In other words, the paper discharge tray 12a forms a slanting surface that faces obliquely downward from the front side to the rear side of the top cover 12 in order to receive and stack a plurality of sheets on which images have been discharged from the paper discharge port 12b. It is provided to do. The paper discharge port 12b is an opening provided above the lower end (rear end) of the paper discharge tray 12a in the outer cover 11, and is formed in a slit shape having a longitudinal direction in the paper width direction. .

  The paper transport unit 2 includes a paper cassette 21, a paper feed roller 22, a transport roller 23, a registration roller 24, a paper discharge drive roller 25, and a paper discharge driven roller 26. The sheet is transported from the sheet cassette 21 to the sheet discharge tray 12a along the path PP.

  The paper cassette 21 is provided below the main body 10 of the laser printer 1 and is configured to be detachable (that is, easily detachable) from the main body frame 10a by sliding in the front-rear direction. Further, the paper cassette 21 is configured so that a large number of sheet-like papers can be accommodated inside in a stacked state. The paper feed roller 22 is rotatably supported at the bottom of the main body 10 and is disposed so as to be in contact with the front end of the paper stored in the paper cassette 21 in a stacked state. The paper feed roller 22 is configured to be driven to rotate so as to pick up paper one by one from the paper cassette 21 and transport the paper toward the transport roller 23.

  The transport roller 23 is provided downstream of the paper feed roller 22 in the paper transport direction, and feeds the paper picked up by the paper feed roller 22 toward the registration roller 24. The registration roller 24 is disposed on the upstream side in the paper transport direction from the transfer position described later so as to face the bottom of the process cartridge 3 with the paper transport path PP interposed therebetween, and adjusts the paper orientation and transport timing. At the same time, the paper is fed toward the transfer position.

  The paper discharge driving roller 25 and the paper discharge driven roller 26 are provided in the vicinity of the paper discharge port 12b so that the paper on which the toner image is formed can be discharged onto the paper discharge tray 12a through the process cartridge 3 and the fixing unit 6. It has been. The paper discharge driven roller 26 is provided so as to face the paper discharge driving roller 25 with the paper conveyance path PP interposed therebetween, and is rotatably supported so as to rotate with the paper discharge driving roller 25. .

  A process cartridge 3 as a developing cartridge of the present invention is detachably accommodated in the main body 10. That is, the process cartridge 3 can be easily attached to and detached from the main body 10 for replacement or maintenance of the laser printer 1. Specifically, the process case 31 forming a part of the casing of the process cartridge 3 is configured to be detachable from the main body frame 10a. The process case 31 includes a photosensitive drum 32 and a charger 33. A transfer roller 34 and a resist roller 35 are mounted.

  The photosensitive drum 32 is a cylindrical member having a photosensitive layer formed on the outer peripheral portion thereof, and is rotatably supported by the process case 31. That is, the photosensitive drum 32 is driven to rotate about an axis parallel to the paper width direction, so that the electrostatic latent image carrying surface, which is the peripheral surface thereof, moves in a direction perpendicular to the paper width direction. Yes. The charger 33 is provided to face the electrostatic latent image carrying surface in order to uniformly charge the electrostatic latent image carrying surface.

  The transfer roller 34 is located at a transfer position on the downstream side in the moving direction of the electrostatic latent image carrying surface due to the rotation of the photosensitive drum 32 relative to the position facing the charger 33, with the electrostatic latent image sandwiched between the paper transport path PP. It is provided so as to face the image carrying surface. The transfer roller 34 rotates in a direction that rotates with the photosensitive drum 32 (that is, a direction opposite to the rotation direction of the photosensitive drum 32) during image formation. The transfer roller 34 transfers a toner image carried on the peripheral surface of the photosensitive drum 32 onto a sheet by a predetermined voltage applied between the transfer roller 34 and the photosensitive drum 32. The registration roller 35 is provided so as to be exposed to the outside at the bottom of the process case 31, and is rotated with the rotational driving of the registration roller 24 at a position facing the registration roller 24 across the paper transport path PP. It is supported rotatably.

  Further, the toner case 36 which forms a part of the casing of the process cartridge 3 (which forms the casing of the process cartridge 3 together with the process case 31) is configured to be detachable from the process case 31. That is, the toner case 36 can be easily attached to and detached from the process case 31 for replacement or maintenance. The toner case 36 as a casing of the present invention is a box-shaped member made of an insulating synthetic resin, and a toner container TA that is a space inside the toner container 36 stores toner that is a powdery dry developer. Has been.

  In the toner case 36, an opening having a longitudinal direction in the paper width direction is formed at a position facing the photosensitive drum 32 when mounted on the process case 31. A developing roller 37 and a supply roller 38 are provided in the toner case 36 at a position near the opening. An agitator 39 is accommodated in the toner accommodating portion TA. The developing roller 37, the supply roller 38, and the agitator 39 are rotatably supported by the toner case 36.

  The developing roller 37 is located downstream of the position where the electrostatic latent image carrying surface and the charger 33 face each other and upstream of the transfer position in the moving direction of the electrostatic latent image carrying surface due to the rotation of the photosensitive drum 32. At the development position, it is arranged in parallel with the photosensitive drum 32 so as to face the electrostatic latent image carrying surface. In the present embodiment, the developing roller 37 includes a metal developing roller shaft 37a and a semiconductive rubber layer 37b formed around the developing roller shaft 37a. The developing roller 37 as the developer carrying roller of the present invention is configured to carry a thin layer of toner on the smooth cylindrical surface of the rubber layer 37b. In order to supply the charged toner to the electrostatic latent image carrying surface, the developing roller 37 moves in the direction opposite to the rotation direction of the photosensitive drum 32 (that is, the moving direction of the peripheral surface of the developing roller 37 at the above-described developing position). Is driven to rotate (in a rotational direction that is the same as the moving direction of the electrostatic latent image carrying surface).

  In the present embodiment, the supply roller 38 includes a metal supply roller shaft 38a and a sponge layer 38b formed around the metal supply roller shaft 38a. The supply roller 38 as the developer supply roller of the present invention has a sponge layer 38b facing the toner storage portion TA in order to carry the toner stored in the toner storage portion TA on the peripheral surface of the development roller 37. The developing roller 37 is disposed between the toner containing portion TA and the developing roller 37 so as to be in contact with the peripheral surface of the rubber layer 37 b in the developing roller 37.

  The agitator 39 includes a metal agitator shaft 39a and a stirring blade 39b fixed to the agitator shaft 39a. The agitator 39 is rotationally driven in the toner accommodating portion TA in order to agitate the toner accommodated in the toner accommodating portion TA by the agitating blade 39b and send a part thereof toward the supply roller 38. It is like that.

  The scanner unit 4 is disposed above the process cartridge 3. The scanner unit 4 generates a laser beam modulated based on the image data, and the laser beam is aligned along the paper width direction on the electrostatic latent image carrying surface uniformly charged by the charger 33. Scanning, the electrostatic latent image is formed on the electrostatic latent image carrying surface.

  The remaining toner sensor 5 is attached to the main body frame 10 a in order to detect the remaining amount of toner stored in the process cartridge 3. The toner remaining amount sensor 5 as the developer remaining amount detecting means of the present invention includes a light emitting element composed of a light emitting diode and a light receiving element composed of a phototransistor. The light emitting element and the light receiving element are arranged in the paper width direction, and are provided on the inner wall surfaces of the main body frame 10a facing each other with the toner case 36 interposed therebetween. The toner remaining amount sensor 5 is configured to emit light for detecting the remaining amount of toner (remaining amount detection light) from the light emitting element toward the light receiving element, and to generate a signal corresponding to the amount of light received by the light receiving element. ing. Specifically, the toner remaining amount sensor 5 is configured to generate a signal by the light receiving element such that the amount of light received by the light receiving element is about 0 V at the maximum and about 5 V at the minimum. The toner remaining amount sensor 5 changes the signal generated by the light receiving element in accordance with the remaining amount of toner in the toner accommodating portion TA provided between the light emitting element and the light receiving element. (See Japanese Patent Laid-Open No. 2000-318661).

  The fixing unit 6 is disposed on the downstream side in the paper transport direction from the above-described transfer position (position where the photosensitive drum 32 and the transfer roller 34 face each other). The fixing unit 6 includes a heating roller 61 and a counter roller 62. The fixing unit 6 is configured to nip the sheet between the heating roller 61 and the counter roller 62 and heat and press the sheet carrying the toner image to thermally fix the toner image on the sheet. ing.

<Details of process cartridge configuration>
FIG. 2 is an enlarged side view of the periphery of the toner case 36 in the process cartridge 3 shown in FIG. FIG. 3 is a partially exploded side view of the process cartridge 3 (toner case 36) shown in FIG. Hereinafter, the configuration of the process cartridge 3 of the present embodiment will be described in detail with reference to FIGS. 2 and 3.

  The toner case 36 includes a bottom plate 361, a top plate 362, and a pair of side plates 363, and the bottom plate 361 and the pair of side plates 363 are joined together seamlessly. The top plate 362 is provided so as to close the space surrounded by the bottom plate 361 and the pair of side plates 363 from above. The pair of side plates 363 are arranged in the paper width direction and are provided in parallel to each other. A toner remaining amount detection window 364 is provided at the bottom of each of the pair of side plates 363. The toner remaining amount detection window 364 is a transparent or translucent portion provided on the side plate 363, and the above-described remaining amount emitted from the light emitting element toward the light receiving element in the toner remaining amount sensor 5 (see FIG. 1). It is formed so that it can transmit the quantity detection light.

  A gear cover 365 is attached to one of the pair of side plates 363. The gear cover 365 is provided so as to cover a gear mechanism 700, which will be described later, provided on the one side plate 363 side from the outside. An input gear opening 365a that is a through hole is provided in the gear cover 365 at a position near the developing roller shaft 37a and the supply roller shaft 38a. The input gear opening 365a is provided so as to expose an input gear 710 included in a gear mechanism 700 described later toward the outside of the gear cover 365 in the paper width direction. Further, an information detection gear cover portion 365b is provided at a position near the agitator shaft 39a in the gear cover 365 so as to cover a detection gear 760 included in a gear mechanism portion 700 described later from the outside. In order to expose a part of the detection gear 760 to the outside of the gear cover 365, an information detection window 365c is provided in the information detection gear cover portion 365b. The information detection window 365c is a through hole, and is formed in a fan shape with a central angle of about 90 degrees so as to expose about a quarter of the detection gear 760 in a side view in the figure.

<< Gear mechanism >>
The gear mechanism 700 described above is configured to transmit the rotational driving force from the motor M provided in the main body frame 10a to the developing roller shaft 37a, the supply roller shaft 38a, and the agitator shaft 39a. In addition to the above-described input gear 710 for receiving the rotational driving force from the motor M, the gear mechanism unit 700 includes a supply roller driving gear 720, a developing roller driving gear 730, an intermediate gear 740, and an agitator driving gear 750. And the detection gear 760 described above.

  The input gear 710 is rotatably supported by an input gear support shaft 711. The input gear support shaft 711 is provided so as to protrude outward in the paper width direction from the one side plate 363 between the developing roller shaft 37a and the agitator shaft 39a. A coupling engaging recess 712 is provided at the shaft center of the input gear 710. When the process cartridge 3 is mounted on the main body frame 10a, the coupling engagement recess 712 engages with the coupling CP provided on the main body frame 10a, so that the driving force is supplied from the motor M as the driving means. It is configured to be input to the input gear 710. That is, the process cartridge 3 receives a driving force for an image forming operation from the main body frame 10 a via the coupling CP and the coupling engaging recess 712 of the input gear 710.

  The supply roller drive gear 720 is attached to the end of the supply roller shaft 38a so as not to be relatively rotatable. The supply roller drive gear 720 is provided on the same plane as the input gear 710 and below the input gear 710 so as to mesh with the input gear 710. The developing roller driving gear 730 is attached to the end of the developing roller shaft 37a so as not to be relatively rotatable. The developing roller drive gear 730 is provided on the same plane as the input gear 710 and obliquely below the input gear 710 so as to mesh with the input gear 710 and not mesh with the supply roller drive gear 720.

  The intermediate gear 740 is rotatably supported by an intermediate gear support shaft 741. The intermediate gear support shaft 741 is provided between the input gear 710 and the agitator shaft 39a so as to protrude outward from the one side plate 363 in the paper width direction. The intermediate gear 740 is a so-called two-stage gear including an intermediate gear external tooth 742 and an intermediate gear internal tooth 743 provided on the inner side in the paper width direction than the intermediate gear external tooth 742, and is integrally formed. Is formed. The intermediate gear external teeth 742 are provided on the same plane as the input gear 710 so as to mesh with the input gear 710. The intermediate gear inner teeth 743 are provided on the same plane as the agitator gear inner teeth 751 so as to mesh with later-described agitator gear inner teeth 751 in the agitator drive gear 750.

  The agitator drive gear 750 is attached to the end of the agitator shaft 39a so as not to be relatively rotatable. The agitator drive gear 750 is a so-called two-stage gear including the above-described agitator gear inner teeth 751 and agitator gear outer teeth 752 provided outside the agitator gear inner teeth 751 in the paper width direction. Are integrally formed. The agitator gear external teeth 752 are provided on the same plane as the detection gear 760 so as to be able to mesh with the detection gear 760 described above.

<<< Configuration for detecting process cartridge information >>>
The detection gear 760 as a driven member of the present invention is rotatably supported by a detection gear support shaft 761. The detection gear support shaft 761 is provided so as to protrude outward from the one side plate 363 in the paper width direction, obliquely above the front side of the agitator drive gear 750. The detection gear 760 is a so-called missing gear in which a tooth portion 763 is provided on a part of the outer periphery of the substantially disc-shaped detection gear main body portion 762. A gear support shaft 761 is inserted so as to be relatively rotatable. The detection gear 760 is held in a stopped state (rotation phase) by frictional resistance with the detection gear support shaft 761 in a state where the process cartridge 3 is detached from the main body frame 10a.

  The tooth portion 763 is provided in a substantially semicircular arc shape at a portion corresponding to a substantially semicircular portion of the outer periphery of the detection gear main body portion 762. A cutout portion 764 is provided at a position of the detection gear main body 762 opposite to the tooth portion 763. The notch portion 764 is formed in a substantially fan shape having a central angle of about 60 degrees that extends radially outward from the rotation center of the detection gear main body portion 762. On the outer peripheral surface of the detection gear main body 762, the missing tooth portion 765, which is a portion other than the portion where the tooth portion 763 is formed, does not mesh with the agitator gear external tooth 752, thereby driving the agitator. The driving force is transmitted from the motor M to the detection gear 760 via the gear 750 is cut off.

  As described above, the detection gear 760 is connected to the tooth portion 763 only when the driving force from the motor M is first transmitted after the process cartridge 3 in the “initialized” state is mounted on the main body frame 10a. It is configured to be driven only in a limited predetermined driving range in which the agitator gear external teeth 752 mesh with each other. On the other hand, when the process cartridge 3 that has not been “initialized” is mounted on the main body frame 10a, it cannot be driven. .

  A contact protrusion 767 as a moving member of the present invention is provided so as to protrude outward from the outer surface of the detection gear main body 762 in the paper width direction. That is, the contact protrusion 767 is fixed to the detection gear main body 762 so as to move as the detection gear 760 is driven (rotates about the detection gear support shaft 761).

  The contact protrusion 767 is provided so as to extend in the radial direction from the center portion through which the detection gear support shaft 761 in the detection gear main body portion 762 is inserted toward the outer peripheral side. The contact protrusion 767 is formed so that the distal end portion on the outer peripheral side is wider than the proximal end portion on the center portion side (detection gear support shaft 761 side). A protruding portion 768 is provided so as to protrude toward the moving direction of the tooth portion 763 (see the arrow in the figure) due to the rotation of 760. That is, the abutting protrusion 767 is formed in a substantially L shape in a side view by projecting a projecting portion 768 which is a tip portion thereof along the circumferential direction of the detection gear main body 762. Note that the tip of the contact protrusion 767 including the protrusion 768 is formed in a curved shape so that a sharp corner is not formed.

  The contact protrusion 767 is provided corresponding to information on the process cartridge 3. Specifically, a first contact protrusion 767a is provided at a position corresponding to the substantially central portion of the tooth portion 763 in the moving direction described above. In FIG. 3, the second position corresponding to the non-capacity information is located at a position adjacent to the notch 764 and corresponding to the rear end in the moving direction of the missing tooth 765 due to the rotation of the detection gear 760. A contact protrusion 767b is provided. Further, in FIG. 3, a third contact protrusion 767c corresponding to the capacity information is provided at a position corresponding to the rear end portion of the tooth portion 763 in the above moving direction. That is, in FIG. 3, the first contact protrusion 767a, the third contact protrusion 767c, and the second contact protrusion 767a from the front end side to the rear end side in the movement direction of the outer periphery of the detection gear 760 due to the rotation of the detection gear 760. The contact protrusion 767b is provided in this order.

  The first abutting protrusion 767a is an abutting protrusion 767 for detecting the initialization cartridge, and is provided in all the detection gears 760. On the other hand, the second contact protrusion 767b for determining the type of the supply roller 38 as non-capacity information is the process cartridge 3 when the type of the supply roller 38 (the foamed state of the sponge layer in FIG. 1) is a specific one. In the detection gear 760. The third contact protrusion 767c is provided on the detection gear 760 in the process cartridge 3 when the toner storage amount is large (for example, the maximum number of images to be formed is 6000).

  As described above, when the second contact protrusion 767b and the third contact protrusion 767c are provided in addition to the first contact protrusion 767a, the plurality of contact protrusions 767 are detected by the detection gear 760 described above. It is provided at a position where it can come into contact with an actuator 810 included in the information detection unit 800 described later while being driven by the driving range. The first contact protrusion 767a is provided so as to first contact the actuator 810 and pass through the actuator 810 while the detection gear 760 is driven by the above-described predetermined drive range. Further, the second contact protrusion 767b is always in contact with the actuator 810 (described later) while the detection gear 760 is driven by the above-described predetermined drive range (when the detection gear 760 has been driven). It is provided to be in the state of

  The main body frame 10a is provided with an information detection unit 800 and a CPU 900. The information detection unit 800 as detection means of the present invention is arranged at a position facing the detection gear 760 on the inner wall surface of the main body frame 10a in order to detect information about the process cartridge 3 mounted on the main body frame 10a. Yes. The information detection unit 800 includes an actuator 810 and an optical sensor 820. The actuator 810 is provided so as to be in contact with the contact protrusion 767 in the detection gear 760 described above. The optical sensor 820 is configured and arranged to generate a detection signal including a contact level that occurs when the contact protrusion 767 contacts the actuator 810 and a non-contact level that occurs when the contact projection 767 does not contact. The CPU 900 as the cartridge information determination unit of the present invention is mounted on the main body frame 10a based on the detection result by the information detection unit 800, that is, the occurrence state of the contact level and the non-contact level in the detection signal described above. Information about the process cartridge 3 is determined.

  The actuator 810 is swingably supported by a swing support shaft 811. The swing support shaft 811 is provided so as to protrude inward in the paper width direction from the inner wall surface of the main body frame 10a. The actuator 810 includes a base portion 812 that is a substantially arc-shaped plate member through which the swing support shaft 811 is inserted, and a contact claw portion 813 that extends from the base portion 812 toward the contact protrusion 767 of the detection gear 760. The light shielding portion 814 extends from the base portion 812 toward the opposite side of the contact protrusion 767 and is integrally formed.

  A light-shielding protrusion 814a having an arc shape in a side view is formed at the front end in the extending direction of the light-shielding portion 814 so as to protrude toward the optical sensor 820 along the paper width direction. The light shielding protrusion 814a is provided between a light emitting element (not shown) provided in the optical sensor 820 and a light receiving element so as to shield the actuator detection light emitted from the light emitting element toward the light receiving element. . In addition, a spring locking portion 814b is formed in the middle portion in the longitudinal direction of the light shielding protrusion 814a. One end of a tension spring 815 is locked to the spring locking portion 814b. The other end of the tension spring 815 is locked to the inner wall surface of the main body frame 10a. The tension spring 815 is in a direction opposite to the direction in which the light shielding portion 814 swings when the contact claw portion 813 of the actuator 810 comes into contact with the protrusion 768 of the contact projection 767 of the detection gear 760 and is pushed down. A light shielding portion 814 is provided to be urged.

  Further, a stopper projection 816 is formed on the base 812 so as to protrude radially outward (upward in the drawing) on the upper side (opposite side to the tension spring 815) on the outer peripheral surface thereof. On the other hand, on the inner wall surface of the main body frame 10a, a stopper abutting portion S that can come into contact with the stopper projecting portion 816 is fixed at the destination of the stopper projecting portion 816 due to the urging force of the tension spring 815. The stopper projection 816 contacts the stopper contact portion S in a state where the contact claw portion 813 of the actuator 810 is not pushed down (a state where it does not contact the projection 768 of the contact projection 767 of the detection gear 760). Thus, the light shielding protrusion 814a is provided so as to be held at the light shielding position facing the optical sensor 820.

<Operation / Effects of Configuration of Embodiment>
4A to 4F are diagrams illustrating the operation of the detection gear 760 and the information detection unit 800 illustrated in FIGS. 2 and 3. Hereinafter, the operations and effects of the configuration of the present embodiment will be described with reference to FIGS. 1 to 3 and FIGS. 4A to 4F.

  As shown in FIGS. 3 and 4A, the initialized process cartridge 3 is in a state where the rotation phase of the detection gear 760 is initialized (when the tooth 763 is mounted on the main body frame 10a, The front end portion in the moving direction is engaged with the agitator gear external teeth 752 while being in contact therewith). Incidentally, the initialized process cartridge 3 includes the following three modes. (1) a new process cartridge 3, (2) a toner case 36 removed from the process case 31 of the used process cartridge 3, and a new toner case 36 attached, (3) a process in the used process cartridge 3 The toner case 36 is removed from the case 31 and the toner case 36 is replenished with toner, and then the toner case 36 is attached to the process case 31 again.

  Before the process cartridge 3 is mounted on the main body frame 10a, as shown in FIG. 4A, the light shielding portion 814 has an elastic urging force by the tension spring 815, and the stopper protrusion 816 and the stopper abutting portion S. Is held at the above-described light blocking position that blocks the actuator detection light in the optical sensor 820. At this time, the optical sensor 820 generates a “non-contact level” signal. When the initialized process cartridge 3 is mounted on the main body frame 10a, the detection gear 760 moves relative to the information detection unit 800 in the direction of arrow A as shown in FIG. 4A.

  When the initialized process cartridge 3 is mounted on the main body frame 10a, as shown in FIG. 4B, the protrusion 768 in the first contact protrusion 767a for detecting the initialization cartridge is in contact with the actuator 810. The nail part 813 is pushed down. Then, the light shielding portion 814 swings (rotates) about the swing support shaft 811 in the direction of arrow B in the figure against the elastic biasing force of the tension spring 815. That is, the light shielding unit 814 moves from the above-described light shielding position to a non-light shielding position where the actuator detection light in the optical sensor 820 is not blocked. As a result, the optical sensor 820 generates a “contact level” signal.

  When the CPU 900 detects a change in the signal level in the optical sensor 820 as described above, the CPU 900 recognizes that the mounting operation of the process cartridge 3 with respect to the main body frame 10a is performed, and starts a warm-up operation. When the mounting operation of the process cartridge 3 on the main body frame 10a is performed while the power is off, the “contact level” signal is continuously generated for a predetermined time or more by the optical sensor 820 from the time when the power is turned on. It will be. Also in this case, the CPU 900 starts a warm-up operation. In this warming-up operation, image formation is not performed, and the toner in the toner container TA is agitated by rotating the agitator 39.

  When the warm-up operation is started, the agitator drive gear 750 is driven to rotate, so that the detection gear 760 rotates in the direction of arrow C shown in FIG. 4C from the state shown in FIG. 4B. When the first contact protrusion 767a moves from the position facing the actuator 810 (contact claw portion 813) and passes through the contact claw portion 813 by the rotation of the detection gear 760, as shown in FIG. 4C. Then, a state in which any contact protrusion 767 is not in contact with the contact claw portion 813 once occurs. At this time, the optical sensor 820 generates a “non-contact level” signal.

  As described above, when the initialized process cartridge 3 is mounted on the main body frame 10a, “contact level” − “non-contact level” at a predetermined timing from the start of driving (the rotation of the detection gear 760). A pulse (initialization detection pulse) is generated. When the generation of such a pulse is detected by the CPU 900, the CPU 900 recognizes that the initialized process cartridge 3 is mounted on the main body frame 10a, and performs recording for determining the life of the process cartridge 3 (toner case 36). Perform initial operations such as resetting the number counter.

  When the detection gear 760 is provided with the third contact protrusion 767c, as shown in FIGS. 4D and 4E, the third contact protrusion 767c contacts the contact claw portion at a predetermined timing from the start of driving. The contact claw portion 813 is pushed down by the protruding portion 768 of the third contact protrusion 767c. Then, as shown in FIG. 4E, the light shielding portion 814 moves to the non-light shielding position, and a signal of “contact level” is generated in the optical sensor 820. Thereafter, when the third contact protrusion 767c passes the contact claw portion 813, the light shielding portion 814 returns to the light shielding position, and a signal of “non-contact level” is generated in the optical sensor 820. That is, when the detection gear 760 is provided with the third contact protrusion 767c, the optical sensor 820 uses the “non-contact level” − “contact level” − “non-contact level” pulse (capacity detection pulse). ) Occurs at a predetermined timing (after the above-described initialization detection pulse) from the start of driving. On the other hand, when the detection gear 760 is not provided with the third contact protrusion 767c, the capacitance detection pulse is not generated. Therefore, the capacity information is determined by the CPU 900 based on whether or not the capacity detection pulse is generated.

  As shown in FIG. 4F, when the detection gear 760 rotates until the tooth portion 763 passes through the agitator gear external teeth 752 and does not mesh, the detection gear 760 does not rotate any more and the detection gear 760 rotates. The phase is held in the state shown in FIG. 4F. In this state, when the detection gear 760 is provided with the second contact protrusion 767b, the contact claw portion 813 contacts the protrusion 768 in the second contact protrusion 767b as shown in FIG. 4F. Will remain depressed. In this case, the “contact level” signal is continuously generated by the optical sensor 820. On the other hand, when the detection gear 760 is not provided with the second contact protrusion 767b, the signal “non-contact level” remains generated in the optical sensor 820. Therefore, the CPU 900 determines the non-capacity information based on the signal generation level of the optical sensor 820 after the detection gear 760 is driven.

  Even if the process cartridge 3 in use is once detached from the main body frame 10a for some reason such as jam processing, the detection gear 760 is stopped (rotation phase) due to frictional resistance with the detection gear support shaft 761. Retained. Therefore, when the process cartridge 3 is remounted, the signal generated by the optical sensor 820 differs depending on whether or not the second contact protrusion 767b is provided on the detection gear 760.

  That is, when the second contact protrusion 767b is provided on the detection gear 760, as shown in FIG. 4F, the contact claw portion 813 contacts the protrusion 768 in the second contact protrusion 767b and pushes down. It will be in the state. If this state continues for a predetermined time, the “contact level” signal is continuously generated in the optical sensor 820 for a predetermined time or more as described above, and the CPU 900 starts a warm-up operation. However, in this case, since the detection gear 760 does not rotate, the signal “contact level” is further continuously generated by the optical sensor 820. For this reason, the initialization detection pulse generated when the initialization cartridge is mounted is not generated. Therefore, the CPU 900 does not perform initialization cartridge mounting determination. Further, the CPU 900 determines the non-capacity information based on the presence of the second contact protrusion 767b.

  On the other hand, when the detection gear 760 is not provided with the second contact protrusion 767b, the contact claw portion 813 does not contact the second contact protrusion 767b, and the optical sensor 820 generates a signal of “non-contact level”. It occurs continuously. In this case, the CPU 900 tries a warm-up operation after a predetermined time has elapsed. At this time, if the process cartridge 3 is mounted on the main body frame 10a, a regular pulse signal corresponding to the remaining amount of toner is generated in the remaining toner sensor 5 as will be described later. As a result, the CPU 900 determines whether or not the process cartridge 3 in use, in which the second contact protrusion 767b is not provided on the detection gear 760, is mounted again. When the process cartridge 3 is not attached to the main body frame 10a, or when only the process case 31 where the toner case 36 is not attached is attached to the main body frame 10a, the toner remaining amount sensor 5 receives light. A continuous signal of about 0 V is generated when the amount of light received by the element is maximum.

  As described above, according to the configuration of the present embodiment, whether or not the mounted process cartridge 3 has been initialized after the mounting operation of the process cartridge 3 on the main body frame 10a, the capacity information, The capacity information is acquired well.

  Incidentally, the remaining amount of toner in the process cartridge 3 (toner case 36) can be detected by the toner remaining amount sensor 5 as follows (see Japanese Patent Laid-Open No. 2000-318661). When the agitator 39 rotates in the toner storage portion TA, the toner is stirred by the stirring blade 39b. At this time, the above-described remaining amount detection light passing between the pair of toner remaining amount detection windows 364 is blocked by the stirring blade 39b and the toner stirred thereby, in synchronization with the rotational phase of the stirring blade 39b. It changes regularly. Then, depending on the remaining amount of toner, the degree of occurrence of “low level” in which the output is 3 V or less and “high level” in which the output is about 5 V changes.

  As the toner amount decreases, the duty ratio, which is the ratio of “low level” in the output signal, changes. Then, when the duty ratio reaches a predetermined ratio, toner empty is determined. Here, the type of the supply roller 38 as the non-capacity information in the present embodiment greatly affects the above-described toner empty determination.

  Specifically, the first type supply roller 38 that absorbs a small amount of toner (when the foaming rate of the sponge layer 38b is low or the foamed state is a single bubble) and the second type that absorbs a large amount of toner. In comparison with the supply roller 38, the amount of toner that is actually stirred in the toner accommodating portion TA is larger in the first type than in the second type if the remaining amount of toner is the same. Therefore, when the first type supply roller 38 is mounted and when the second type supply roller 38 is mounted, the same predetermined toner remaining amount (the remaining amount of toner in the entire toner case 36) Tr [unit: g] When toner empty determination is performed, the duty ratio threshold for toner empty determination is set to be lower for the first type than for the second type.

  Now, if the first type supply roller 38 with a small amount of toner absorption is actually mounted, the threshold value for the second type supply roller 38 with a large amount of toner absorption is erroneously applied. Then, since the toner empty determination is not performed until the duty ratio becomes higher than the original threshold value, the remaining amount of toner in the entire toner case 36 becomes smaller than an appropriate amount (Tr). As a result, the formed image may be disturbed.

  On the contrary, the threshold value for the first type supply roller 38 having a small amount of toner absorption is erroneously applied where the second type supply roller 38 having a large amount of toner absorption is mounted. Then, the toner empty determination is performed earlier with a duty ratio lower than the original threshold. For this reason, the toner empty determination is performed in a state where the remaining amount of toner in the entire toner case 36 is larger than the appropriate amount (Tr), and the process cartridge 3 (toner case 36) that can be used still has a long service life. It will be exchanged without being greeted.

  On the other hand, according to the configuration of the present embodiment, the type of the supply roller 38 is reliably determined based on the presence or absence of the second contact protrusion 767b. Then, based on the determination result, the duty ratio threshold for toner empty determination is reliably set. Therefore, according to the configuration of the present embodiment, the toner empty determination is performed satisfactorily.

  In particular, after a process cartridge 3 in use is once detached, a different process cartridge 3 in use may be remounted. In this case, the remaining amount of toner and the original capacity information (initial capacity) are different between the process cartridges 3 before and after remounting, so that the life determination based on the capacity information based on the presence / absence of the third contact protrusion 767c is appropriate. There is a possibility of disappearing. However, according to the configuration of the present embodiment, since the toner empty determination by the toner remaining amount sensor 5 is performed better (accurate) than the conventional apparatus, the life determination of the process cartridge 3 is always performed well.

<List of examples of modification>
It should be noted that the above-described embodiments are merely examples of typical embodiments of the present invention that the applicant has considered to be the best at the time of filing of the present application. Therefore, the present invention is not limited to the above-described embodiment. Therefore, it goes without saying that various modifications can be made to the above-described embodiment within the scope not changing the essential part of the present invention.

  Hereinafter, some typical modifications will be exemplified. In the following description of the modified examples, the same reference numerals as those in the above-described embodiment can be used for those having the same configuration and function as the components described in the above-described embodiment. And about description of this member, the description in the above-mentioned embodiment shall be used in the range which is not technically consistent. However, it goes without saying that the modifications are not limited to those listed below. In addition, a plurality of modified examples can be applied in a composite manner as appropriate within a technically consistent range.

  The application target of the present invention is not limited to a monochromatic laser printer. For example, the present invention can be suitably applied to a so-called electrophotographic image forming apparatus such as a color laser printer or a monochromatic and color copying machine. At this time, the shape of the photosensitive member may not be a drum shape as in the above-described embodiment. For example, a flat plate shape or an endless belt shape may be used.

  The process case 31 and the toner case 36 in the process cartridge 3 may not be separable. Alternatively, only the toner case 36 may be detachable from the main body frame 10a.

  The third contact protrusion 767c may be provided on the detection gear 760 in the process cartridge 3 when the toner storage amount is small (for example, the maximum number of images to be formed is 3000). Further, there may be four or more types of contact protrusions 767. Further, the second contact protrusion 767b can be provided corresponding to information other than the type of the supply roller 38 (type of toner (color, material, manufacturing method, charging characteristics), type of the developing roller 37, etc.).

  Other modifications not specifically mentioned are naturally included in the technical scope of the present invention without departing from the essential part of the present invention. In addition, in each element constituting the means for solving the problems of the present invention, elements expressed functionally and functionally include the specific structures disclosed in the above-described embodiments and modifications, It includes any structure that can realize this action / function. Furthermore, the contents of other applications and publications cited in this specification (including the specification and drawings) are included in a part of this specification, and are within a scope that is technically consistent as necessary. Can be incorporated by reference.

DESCRIPTION OF SYMBOLS 1 ... Laser printer 10 ... Main body part 10a ... Main body frame 3 ... Process cartridge 31 ... Process case 36 ... Toner case 364 ... Toner residual amount detection window 38 ... Supply roller 38b ... Sponge layer 39 ... Agitator 39b ... Stirring blade 5 ... Toner remaining Quantity sensor 760 ... detection gear 767 ... contact protrusion 767a ... first contact protrusion 767b ... second contact protrusion 767c ... third contact protrusion 800 ... information detection unit 810 ... actuator 820 ... light sensor 900 ... CPU
TA: Toner container

Japanese Patent Laid-Open No. 2000-221781 JP 2006-243073 A JP 2006-267994 A

Claims (8)

In an image forming apparatus comprising a main body and an exchangeable developing cartridge configured to be easily attached to and detached from the main body,
A driving means provided in the main body for transmitting a driving force for an image forming operation to the developing cartridge;
Provided in the developing cartridge and configured to be driven only within a predetermined driving range limited only when the driving force is transmitted from the driving means for the first time after the developing cartridge is mounted on the main body. A driven member,
A plurality of moving members fixed to the driven member so as to move as the driven member is driven, and provided corresponding to information on the plurality of developing cartridges;
An actuator provided so as to be able to come into contact with the moving member, and a detection signal including a contact level generated when the moving member contacts the actuator and a non-contact level generated when the moving member does not contact is generated. Detecting means configured to:
Cartridge information determination means for determining the information based on the occurrence state of the contact level and the non-contact level in the detection signal;
With
The plurality of moving members are
A first moving member corresponding to whether or not the developing cartridge is in an initialized state;
A second moving member corresponding to non-capacity information, which is information different from capacity information relating to the amount of developer contained in the developing cartridge or the maximum number of recording media capable of forming an image depending on the amount of developer;
Only including,
The image forming apparatus, wherein the second moving member is provided so as to always contact the actuator in a state where the driven member is driven by the predetermined driving range . The image forming apparatus according to claim 1 ,
The plurality of moving members are
The image forming apparatus further comprising a third moving member corresponding to the capacity information. The image forming apparatus according to claim 1 , wherein:
2. The image forming apparatus according to claim 1, wherein the second moving member is provided corresponding to information on characteristics of a roller-like member that is rotationally driven during an image forming operation. The image forming apparatus according to claim 3 .
A developer remaining amount detecting means for detecting the remaining amount of the developer stored in the developing cartridge;
The developing cartridge is
A box-shaped casing configured to store the developer in a developer storage portion which is an internal space;
A developer carrying roller supported rotatably by the casing and configured to carry a thin layer of the developer on a smooth cylindrical peripheral surface;
The developer container is rotatably supported by the casing and faces the developer container in order to carry the developer contained in the developer container on the peripheral surface of the developer carrying roller. A developer supply roller disposed between the developer accommodating portion and the developer carrying roller so as to be in contact with a peripheral surface;
With
The image forming apparatus, wherein the second moving member is provided corresponding to information on the developer supply roller. In a replaceable developing cartridge configured to be easily attached to and detached from the main body in the image forming apparatus,
When receiving the driving force from the driving means provided in the main body for transmitting the driving force for the image forming operation to the developing cartridge for the first time after the mounting operation of the developing cartridge to the main body. A driven member configured to be driven only by a limited predetermined driving range; and
A plurality of moving members fixed to the driven member so as to move as the driven member is driven, and provided corresponding to information on the plurality of developing cartridges;
With
The plurality of moving members are
A first moving member corresponding to whether or not the developing cartridge is in an initialized state;
A second moving member corresponding to non-capacity information, which is information different from capacity information relating to the amount of developer contained in the developing cartridge or the maximum number of recording media capable of forming an image depending on the amount of developer;
Only including,
The second moving member is provided in the main body portion in a state where the driven member is driven within the predetermined driving range, and does not contact with the contact level generated when the moving member contacts the actuator. A developing device characterized by being provided so as to protrude toward the actuator so as to always contact the actuator in the detection means configured to generate a detection signal including a non-contact level that sometimes occurs. cartridge. The developing cartridge according to claim 5 ,
The plurality of moving members are
A developing cartridge further comprising a third moving member corresponding to the capacity information. The developing cartridge according to claim 5 or 6 ,
2. The developing cartridge according to claim 1, wherein the second moving member is provided corresponding to information on characteristics of a roller-like member that is rotationally driven during an image forming operation. The developing cartridge according to claim 7 ,
A box-shaped casing configured to store the developer in a developer storage portion which is an internal space;
A developer carrying roller supported rotatably by the casing and configured to carry a thin layer of the developer on a smooth cylindrical peripheral surface;
The developer container is rotatably supported by the casing and faces the developer container in order to carry the developer contained in the developer container on the peripheral surface of the developer carrying roller. A developer supply roller disposed between the developer accommodating portion and the developer carrying roller so as to be in contact with a peripheral surface;
Further comprising
2. The developing cartridge according to claim 1, wherein the second moving member is provided corresponding to information relating to the developer supply roller.

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