JP2005331843A - Photoreceptor unit, processing cartridge, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly maintain a torque margin of a motor driving a photoreceptor when mounting a photoreceptor unit including the photoreceptor and a process cartridge to rotate the photoreceptor inside an image forming apparatus. <P>SOLUTION: The photoreceptor unit 3 comprises the photoreceptor 12 rotated in a sub-scanning direction; a holding case 13 rotatably holding the photoreceptor 12; and a storing part 17 mounted on the holding case 13 and readably storing load torque necessary for rotating the photoreceptor 12 by a reading part. Even when the load torque necessary for rotating the photoreceptor 12 of each photoreceptor unit 3 has irregularity for each photoreceptor unit 3, the motor 22 rotating the photoreceptor 12 can be driven so as to maintain the optimum torque margin in response to the load torque for each photoreceptor unit 3 since the load torque for each photoreceptor 3 can be sensed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photoreceptor unit, a process cartridge, and an image forming apparatus using these photoreceptor unit or process cartridge.

  In recent years, in image forming apparatuses such as laser printers and digital copying machines, photosensitive units such as a photosensitive drum and a photosensitive belt are held in a holding case to form a unit, and the photosensitive drum is a charger and a developing unit. More and more, process cartridges that are integrated with at least one process member such as a cleaning device and housed in a cartridge case are increasing. Further, these photoreceptors are driven to rotate by a motor provided in the image forming apparatus, and stepping motors are widely used as the motors (see Patent Documents 1 and 2).

  In such a photoreceptor unit or process cartridge, variations in part dimensions, assembly positions, etc. occur, and the load torque for rotating the photoreceptor due to these variations is different for each photoreceptor unit, each process cartridge. It is different depending on the process cartridge.

JP 2002-256091 A JP-A-9-281757

  In the inventions disclosed in Patent Documents 1 and 2 described above, the driving torque of the stepping motor is not changed according to the difference in load torque of each process cartridge. For this reason, if the torque margin of the stepping motor with respect to the load (photosensitive member) to be driven is too large, there arises a problem that the vibration of the stepping motor increases and noise increases. On the other hand, if the torque margin of the stepping motor with respect to the load (photosensitive member) to be driven is small, there arises a problem that motor step-out occurs and driving may become impossible.

  An object of the present invention is to properly maintain a torque margin of a motor for driving a photosensitive member when the photosensitive member unit or process cartridge including the photosensitive member is mounted in the image forming apparatus and the photosensitive member is rotationally driven. .

  According to a first aspect of the present invention, there is provided a photoconductor unit that is rotationally driven in a sub-scanning direction, a holding case that rotatably holds the photoconductor, and a rotation case that is attached to the holding case and rotationally drives the photoconductor. And a storage unit that stores a load torque necessary for making the reading unit readable by the reading unit.

  According to a second aspect of the present invention, in the photosensitive member unit according to the first aspect, the passive-side engagement is detachably engaged with a driving-side engaging portion provided on a rotating shaft that transmits a rotational driving force to the photosensitive member. A coupling portion is provided on the photosensitive member, and the photosensitive member and the rotating shaft are detachably connected by engagement / disengagement of the driving side engagement portion and the passive side engagement portion, and the passive side engagement portion And the drive-side engagement portion are engaged and disengaged by sliding the photoreceptor along the main scanning direction of the photoreceptor.

  According to a third aspect of the present invention, in an image forming apparatus for forming a toner image on a photosensitive member rotated in the sub-scanning direction and transferring the formed toner image to a recording medium, the image forming apparatus is detachably mounted in a main body case. A photosensitive unit according to claim 1 or 2, and a reading unit connected to the storage unit of the photosensitive unit mounted in the main body case and reading load torque information stored in the storage unit, A motor that rotationally drives the photosensitive member; and a current value setting unit that sets a drive current value to be applied to the motor according to a reading result of the reading unit.

  According to a fourth aspect of the present invention, there is provided a process cartridge according to the present invention, wherein the photosensitive member is driven to rotate in the sub-scanning direction, at least one process member among a plurality of process members including a charger, a developing device, and a cleaner. And a cartridge case that holds at least one process member, and a storage unit that is attached to the cartridge case and stores a load torque necessary for rotationally driving the photosensitive member so as to be readable by the reading unit; It comprises.

  According to a fifth aspect of the present invention, in the process cartridge according to the first aspect, the passive side engagement is detachably engaged with a driving side engaging portion provided on a rotating shaft that transmits a rotational driving force to the photoconductor. Is provided on the photosensitive member, and the photosensitive member and the rotating shaft are detachably connected by engaging / disengaging the driving side engaging portion and the passive side engaging portion, and the passive side engaging portion Engagement / disengagement with the driving side engaging portion is performed by sliding the photosensitive member along the main scanning direction of the photosensitive member.

  According to a sixth aspect of the present invention, in an image forming apparatus for forming a toner image on a photosensitive member rotated in the sub-scanning direction and transferring the formed toner image to a recording medium, the image forming apparatus is detachably mounted in a main body case. 6. The process cartridge according to claim 4 or 5, a reading unit connected to the storage unit of the process cartridge mounted in the main body case and reading a load torque stored in the storage unit, and the photoconductor And a current value setting means for setting a drive current value to be applied to the motor in accordance with a reading result of the reading unit.

  According to the first aspect of the present invention, even if the load torque necessary for rotationally driving the photoconductor of each photoconductor unit varies for each photoconductor unit, the load torque for each photoconductor unit is detected. It is possible to drive the motor for rotating the photoconductor so as to maintain an optimum torque margin corresponding to the load torque of each photoconductor unit.

  According to the second aspect of the present invention, the photosensitive member unit can be engaged with and disengaged from the rotation shaft provided in the image forming apparatus by sliding the photosensitive member along the main scanning direction of the photosensitive member. The photosensitive unit can be easily attached to and detached from the image forming apparatus.

  According to the third aspect of the present invention, when each photoconductor unit is mounted on the image forming apparatus and used, the load torque necessary for rotationally driving the photoconductor stored in the storage unit is applied to the image forming apparatus. By setting a drive current value to be applied to the motor that drives the photoconductor to rotate according to the read result, the motor of the motor that drives the photoconductor of each photoconductor unit can rotate. The torque margin can be adjusted to an optimum value, and vibrations and noises that occur because the motor torque margin is too large can be suppressed, and motor step-out that occurs because the motor torque margin is small can be prevented.

  According to the fourth aspect of the present invention, even if the load torque necessary for rotationally driving the photosensitive member of each process cartridge varies for each process cartridge, the load torque for each process cartridge can be detected. In addition, the motor for rotating the photosensitive member can be driven so as to maintain an optimum torque margin corresponding to the load torque of each process cartridge.

  According to the fifth aspect of the present invention, the process cartridge can be engaged with and disengaged from the rotation shaft provided in the image forming apparatus by sliding the photoreceptor along the main scanning direction of the photoreceptor. The process cartridge can be easily attached to and detached from the forming apparatus.

  According to the sixth aspect of the present invention, when each process cartridge is mounted on the image forming apparatus and used, the load torque necessary for rotationally driving the photosensitive member stored in the storage unit is provided in the image forming apparatus. By setting the drive current value to be applied to the motor that rotationally drives the photoconductor according to the read result, the torque margin of the motor that rotationally drives the photoconductor is set to the optimum value. It is possible to adjust the vibration and noise generated because the torque margin of the motor is too large, and to prevent motor step-out occurring because the torque margin of the motor is small.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a longitudinal side view showing a schematic structure of a copying machine as an image forming apparatus, FIG. 2 is a longitudinal front view showing a mounting structure of a photosensitive unit, and FIG. 3 is a longitudinal front view explaining a mounting structure of the photosensitive unit. FIG. 4 is a block diagram schematically showing the electrical connection of each part provided in the copying machine, and FIG. 5 is a flowchart for explaining the setting of the drive current value of the stepping motor according to the load torque information.

  As shown in FIG. 1, a photoconductor unit 3, a scanning optical system 4, an imaging optical system 5, a charger 6, a developing device 7, and a transfer device 8 are disposed in a main body case 2 of a copying machine 1 that is an image forming apparatus. A cleaning device 9, a fixing device 10, a paper feed cassette 11 and the like are arranged. The photoconductor unit 3 includes a drum-shaped photoconductor 12 and a holding case 13 that holds the photoconductor 12 so as to be rotatable in the direction around the center line (sub-scanning direction). A contact glass 14 on which a document is placed and a thick plate 15 that covers the top of the contact glass 14 so as to be openable and closable are provided on the upper portion of the main body case 2.

  The charger 6 is a conductive roller member formed in a roller shape, and a charging bias voltage is supplied to the charger 6 from a power supply device (not shown) so that the outer peripheral surface of the photoconductor 12 is made uniform. Charge.

  The scanning optical system 4 optically scans an image of a document placed on the contact glass 14. Scanning light reflected on the document surface is obtained by optical scanning of the scanning optical system 4, and this scanning light is imaged on the outer peripheral surface of the photoconductor 12 by the imaging optical system 5. Thereby, the electrostatic latent image corresponding to the image of the original is written on the outer peripheral surface of the photoconductor 12 uniformly charged by the charger 6.

  Toner is stored in the developing device 7, and this toner is supplied to the photosensitive member 12, and the supplied toner is attached to the electrostatic latent image to visualize the electrostatic latent image on the photosensitive member 12 as a toner image. Let

  The transfer unit 8 is supplied with a transfer bias voltage from the power supply device, and thereby the photoconductor 12 is supplied to the recording medium P fed between the transfer unit 8 and the photoconductor 12 and fed from the paper feed cassette 11. The upper toner image is transferred.

  After the toner image is transferred to the recording medium P, the cleaning device 9 cleans the toner remaining on the photoreceptor 12.

  The fixing device 10 melts the toner by applying heat and pressure to the recording medium P on which the toner image is transferred, and fixes the toner image on the recording medium P.

  In such a configuration, in the copying machine 1, when an original is placed on the contact glass 14 and the copy start key is pressed, the image of the original is read by the scanning optical system 4, and the electrostatic image corresponding to the read image is obtained. A latent image is formed on the photoreceptor 12 by the imaging optical system 5. This electrostatic latent image is visualized as a toner image by the toner supplied from the developing device 7. On the other hand, when the copy start key is pressed, the feeding of the recording medium P from the inside of the paper feeding cassette 11 is started, and the recording medium P is fed to the transfer position between the photosensitive member 12 and the transfer unit 8 to thereby become the photosensitive member. 12 is transferred to the recording medium P. The recording medium P onto which the toner image has been transferred is fixed on the fixing device 10 and then discharged onto the discharge tray 16. The photosensitive member 12 starts to rotate around the center line as the copy start key is pressed. This rotational speed is determined by the scanning speed by the imaging optical system 5 and the transport speed of the recording medium P at the transfer position. Synchronized.

  Under such a configuration, characteristic portions of the present embodiment will be described. As shown in FIG. 2, the photoconductor unit 3 includes a photoconductor 12 and a holding case 13 that rotatably holds the photoconductor 12, and is detachably mounted in the main body case 2. The holding case 13 is provided with a semiconductor storage unit 17 which is a storage unit storing a load torque necessary for rotating the photosensitive member 12. The load torque required for rotationally driving the photoconductor 12 is caused by an error due to variations in the dimensions of the photoconductor 12, the holding case 13, and other components constituting the photoconductor unit 3, assembling variations, and the like. Therefore, there is a variation for each photoconductor unit 3. The load torque stored in the semiconductor storage unit 17 is measured for each photoconductor unit 3 after the photoconductor unit 3 is assembled.

  The semiconductor storage unit 17 has a conductive terminal 18, and the conductive terminal 18 is provided in the main body case 2 in a state where the photosensitive unit 3 is mounted in the main body case 2, and the load in the semiconductor storage unit 17. It is connected to a reading unit 19 (see FIG. 4) that reads torque information.

  In the main body case 2, a rotating shaft 20 is provided for transmitting a rotational driving force to the photoconductor 12 in the photoconductor unit 3 mounted in the main body case 2. One end of the rotary shaft 20 can be inserted into the photoreceptor 12, and a large-diameter gear 21 is fixed to the other end of the rotary shaft 20. The large diameter gear 21 meshes with a motor gear 23 of a stepping motor 22 which is a motor provided in the main body case 2.

  Flange 24 and 25 are fitted to both ends of the rotating shaft 20, and the rotating shaft 20 is fitted to the flanges 24 and 25 so as to be slidable along the center line direction (main scanning direction of the photoconductor 12). ing.

  A plurality of grooves 26 which are passive side engaging portions are formed in the inner peripheral portion of one flange 25 in the circumferential direction. A joint 27 is assembled to the outer peripheral portion of the rotary shaft 20 so as to rotate integrally with the rotary shaft 20, and a plurality of claws 28 as drive side engaging portions are formed on the joint 27. The grooves 26 and the claws 28 are engaged when the photosensitive unit 3 is mounted in the main body case 2 and are disengaged when the photosensitive unit 3 is removed from the main body case 2. Has been. Further, the engagement and disengagement between the grooves 26 and the claws 28 is performed by sliding the photoreceptor unit 3 along the center line direction (main scanning direction) of the photoreceptor 12. The photoreceptor 12 and the rotary shaft 20 are detachably connected by engaging and disengaging these grooves 26 and claws 28.

  As shown in FIG. 4, the copying machine 1 has a controller 30 for controlling each unit. The controller 30 includes a central processing unit (CPU) 31 that centrally controls each unit and various programs executed by the CPU 31. Are connected by a bus line 34. A ROM (Read Only Memory) 32 that stores the data, a RAM (Random Access Memory) 32 that functions as a work area of the CPU 31, and the like are connected. The CPU 31 includes a reading unit 19 that reads load torque information in the semiconductor storage unit 17, a stepping motor 22 through a motor drive unit 22a, an operation panel through an input / output device control unit 35a, an LCD, and the like. An input / output device 35, a power supply device, and other various loads are connected.

  Here, when the copying machine 1 is driven, as shown in the flowchart of FIG. 5, the load torque information stored in the semiconductor storage unit 17 is read by the reading unit 19 (step S1), and according to the read load torque information. Then, a drive current value to be applied to the stepping motor 22 is set (step S2), and current value setting means for setting the drive current value according to the load torque information is executed. Thereafter, the printing operation is started (step S3).

  Here, according to the present embodiment, when the photoconductor unit 3 is mounted in the main body case 2 and the photoconductor 12 is driven to rotate by the stepping motor 22, the load torque necessary for rotating the photoconductor 12 is used. Can be detected for each photoconductor unit 3, and the drive current value to be applied to the stepping motor 22 is set according to the load torque information, so that the torque margin of the stepping motor 22 for rotating the photoconductor 12 is set. Can be adjusted to an optimum value. Thereby, vibration and noise generated because the torque margin of the stepping motor 22 is too large can be suppressed, and motor step-out that occurs because the torque margin of the stepping motor 22 is small can be prevented.

  Further, when the photoreceptor unit 3 is attached to or detached from the main body case 2, a force is applied to the photoreceptor unit 3 so that the photoreceptor 12 is slid along the center line direction of the photoreceptor 12, so that the groove 26 and the claw 28 are formed. Since it can be done by engaging and disengaging, the attaching / detaching operation of the photosensitive unit 3 in the main body case 2 can be easily performed.

  A second embodiment of the present invention will be described with reference to FIGS. In addition, the same part as the part demonstrated in FIG. 1 thru | or FIG. 5 is shown with the same code | symbol, and abbreviate | omits description.

  FIG. 6 is a longitudinal side view showing a schematic structure of a color printer as an image forming apparatus, and FIG. 7 is a longitudinal side view showing a structure of a process cartridge.

  Four process cartridges 42M, 42C, 42Y, and 42B are detachably mounted in the main body case 41 of the color printer 40. The four process cartridges 42M, 42C, 42Y, and 42B are arranged at equal intervals, and the transfer device 43 is disposed below the process cartridges 42M, 42C, 42Y, and 42B. The process cartridges 42M, 42C, 42Y, and 42B form toner images of different colors (M; magenta, C; cyan, Y; yellow, B; black), and are different in the color of the toner used. Are the same. For this reason, in the description in the specification, the subscripts M, C, Y, and B are omitted as necessary. An optical writing device 44 is disposed above the process cartridge 42 in the main body case 41, and the paper feed cassette 11 is detachably mounted below the process cartridge 42 and the transfer device 43 in the main body case 41.

  The optical writing device 44 includes a light source, a polygon mirror, an fθ lens, a reflection mirror, etc., irradiates a laser beam on the surface of a photoconductor described later according to image data, and electrostatic latent images on the outer circumferential surface of the photoconductor. Form.

  As shown in FIG. 7, the process cartridge 42 is constituted by process members such as a cartridge case 45, a photoreceptor 46 accommodated in the cartridge case 45, a charger 47, a developing device 48, and a cleaning device 49. The cleaning device 49 includes a cleaning blade 49a and a cleaning brush 49b.

  The photoconductor 46 is a member having the same function as the photoconductor of the first embodiment, and writing of an electrostatic latent image is performed by irradiating the laser beam emitted from the optical writing device 44. .

  The charger 47 is a member having the same function as the charger 6 of the first embodiment, and uniformly charges the outer peripheral surface of the photoreceptor 46.

  The developing device 48 is a member having the same function as the developing device 7 of the first embodiment. The developing device 48 stores toner, and supplies the toner to the photoconductor 46 to generate an electrostatic latent image on the photoconductor 46. It is visualized as a toner image.

  The cleaning device 49 is a member having the same function as the cleaning device 9 of the first embodiment, and cleans the toner remaining on the photoreceptor 46 after the toner image is transferred to the recording medium P.

  The transfer device 43 includes a conveyance belt 43a, a driving roller 43b, a stretching roller 43c, four transfer rollers 43d, and the like. The conveyor belt 43a is tensioned by the driving roller 43b and the stretching roller 43c, and is rotated in the direction of the arrow (the counterclockwise direction in the figure) by the driving roller 43b that is rotationally driven by a driving system (not shown). A transfer bias is applied to each of the four transfer rollers 43d from a power supply device (not shown). Then, the transfer belt 43a is pressed from the back surface toward the photoconductor 46 to form a transfer nip. In each transfer nip, a transfer electric field is formed between the photoreceptor 46 and the transfer roller 43d due to the influence of the transfer bias. The toner image formed on the photoreceptor 46 is transferred onto the recording medium P conveyed by the conveying belt 43a due to the influence of the transfer electric field and nip pressure. On the recording medium P, toner images of different colors formed by the process cartridges 42 are superimposed and transferred in the order of M, C, Y, and K, and the recording that is conveyed by the conveying belt 43a by the overlapping transfer. A color toner image is formed on the medium P.

  Here, the semiconductor storage unit 17 that stores a load torque necessary for rotationally driving the photosensitive member 46 in each process cartridge 42 is attached to the cartridge case 45 of each process cartridge 42. The semiconductor storage unit 17 has a conductive terminal 18, and the conductive terminal 18 is provided in the main body case 41 in a state where the process cartridge 42 is mounted in the main body case 41, and the load torque in the semiconductor storage unit 17. It is connected to a reading unit (not shown) that reads information.

  In the main body case 41, four rotation shafts (not shown) are provided for transmitting a rotational driving force to the photosensitive member 46 in the process cartridge 42 mounted in the main body case 41. A large-diameter gear is fixed to these rotary shafts in the same manner as the rotary shaft 20 described in the first embodiment, and the large-diameter gear and the motor gear of the stepping motor mesh with each other. Four stepping motors are provided corresponding to each process cartridge 42.

  The photosensitive member 46 and the rotation shaft are rotated by a groove (passive side engaging portion) formed in a flange fitted to the inner peripheral portion of the photosensitive member 46, as described in the first embodiment. It is connected so that it can be engaged and disengaged by engaging and disengaging a claw (drive side engaging portion) formed on a joint assembled to the outer peripheral portion of the shaft. These grooves and claws are performed by sliding the process cartridge 42 along the center line direction (main scanning direction) of the photosensitive member 46 as in the first embodiment.

  Here, according to the present embodiment, when the process cartridge 42 is mounted in the main body case 41 and the photosensitive member 46 is rotationally driven by the stepping motor, the load torque necessary for rotating the photosensitive member 46 is set for each of the load torques. The stepping motor drive current value can be detected for each process cartridge 42 and the stepping motor drive current value is set as shown in FIG. 5 in accordance with the load torque information. Therefore, the torque of the stepping motor for rotationally driving the photosensitive member 46 is set. The margin can be adjusted to an optimum value. As a result, vibration and noise generated because the torque margin of the stepping motor is too large can be suppressed, and motor step-out that occurs because the torque margin of the stepping motor is small can be prevented.

  In addition, the process cartridge 42 is attached to and detached from the main body case 41 by applying a force to the process cartridge 42 so that the photoconductor 46 is slid along the center line direction of the photoconductor 46 to disengage the groove and the claw. Therefore, the process cartridge 42 can be easily attached to and detached from the main body case 41.

1 is a longitudinal side view showing a schematic structure of a copying machine which is an image forming apparatus according to a first embodiment of the present invention. FIG. 6 is a longitudinal front view showing a mounting structure of the photosensitive unit. It is a vertical front view explaining the attachment / detachment structure of a photoreceptor unit. FIG. 3 is a block diagram schematically showing electrical connection of each unit provided in the copying machine. It is a flowchart explaining control of the drive current value of a stepping motor. It is a vertical side view showing a schematic structure of a color printer which is an image forming apparatus according to a second embodiment of the present invention. It is a vertical side view which shows the structure of a process cartridge.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Main body case 3 Photoconductor unit 12 Photoconductor 13 Holding case 17 Memory | storage part 22 Motor 26 Passive side engaging part 28 Drive side engaging part 40 Image forming apparatus 41 Main body case 42 Process cartridge 45 Cartridge case 46 Photoconductor 47 Charger, process member 48 Developer, process member 49 Cleaning device, process member

Claims (6)

A photoreceptor that is rotationally driven in the sub-scanning direction;
A holding case for rotatably holding the photoreceptor;
A storage unit that is attached to the holding case and stores a load torque necessary for rotating the photosensitive member so as to be readable by the reading unit;
A photoreceptor unit. A passive-side engagement portion that is detachably engaged with a drive-side engagement portion that is provided on a rotating shaft that transmits a rotational driving force to the photoconductor;
The photoconductor and the rotating shaft are detachably connected by the engagement / disengagement of the drive side engagement portion and the passive side engagement portion,
2. The photosensitive unit according to claim 1, wherein the passive engagement portion and the driving engagement portion are engaged and disengaged by sliding the photosensitive member along a main scanning direction of the photosensitive member. In an image forming apparatus that forms a toner image on a photoreceptor that is rotationally driven in the sub-scanning direction, and transfers the formed toner image to a recording medium.
The photoconductor unit according to claim 1 or 2 detachably mounted in the main body case;
A reading unit that is connected to the storage unit of the photosensitive unit mounted in the main body case and reads load torque information stored in the storage unit;
A motor for rotating the photoconductor;
Current value setting means for setting a drive current value to be applied to the motor according to a reading result of the reading unit;
An image forming apparatus comprising: A photoreceptor that is rotationally driven in the sub-scanning direction;
At least one process member of the plurality of process members of the charging device, the developing device, and the cleaning device;
A cartridge case for holding the photosensitive member and at least one process member;
A storage unit which is attached to the cartridge case and stores a load torque necessary for rotationally driving the photoconductor so as to be readable by a reading unit;
A process cartridge comprising: A passive-side engagement portion that is detachably engaged with a drive-side engagement portion that is provided on a rotating shaft that transmits a rotational driving force to the photoconductor;
The photoconductor and the rotating shaft are detachably connected by the engagement / disengagement of the drive side engagement portion and the passive side engagement portion,
5. The process cartridge according to claim 4, wherein the engagement and disengagement between the passive side engaging portion and the driving side engaging portion is performed by sliding the photoconductor along a main scanning direction of the photoconductor. In an image forming apparatus that forms a toner image on a photoreceptor that is rotationally driven in the sub-scanning direction, and transfers the formed toner image to a recording medium.
The process cartridge according to claim 4 or 5, which is detachably mounted in the main body case;
A reading unit that is connected to the storage unit of the process cartridge mounted in the main body case and reads load torque information stored in the storage unit;
A motor for rotating the photoconductor;
Current value setting means for setting a drive current value to be applied to the motor according to a reading result of the reading unit;
An image forming apparatus comprising:

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