JP4659496B2 - Electrophotographic image forming apparatus - Google Patents

Description

  The present invention relates to an electrophotographic image forming apparatus and a process cartridge used therefor.

  In an electrophotographic image forming apparatus using an electrophotographic image process, it has been necessary to replace an electrophotographic photosensitive drum, supply a developer, replace or adjust a developing roller, etc., when the electrophotographic image forming apparatus is used for a long time.

  Therefore, in the electrophotographic image forming apparatus, there is a process cartridge system in which the electrophotographic photosensitive member and the process means acting on the electrophotographic photosensitive member are integrated into a cartridge, and the cartridge can be attached to and detached from the main body of the image forming apparatus. It has been adopted. According to this process cartridge system, the apparatus can be maintained by the user himself / herself without depending on the service person, so that the operability can be remarkably improved. Therefore, this process cartridge system is widely used in electrophotographic image forming apparatuses.

  The above-described electrophotographic image forming apparatus employs a technique of detecting the life of a process cartridge and displaying it on an operation panel of the apparatus main body or a display of a computer (see Patent Document 1).

Japanese Patent Laid-Open No. 10-133456

  However, in the life detection as described above, it is not identified whether or not the process cartridge has reached the end of its life. Therefore, if a process cartridge that has reached the end of its life has been removed from the apparatus main body, it is a new process cartridge. It was difficult to distinguish whether the process cartridge reached the end of its service life. For this reason, a used process cartridge may be erroneously remounted in the apparatus main body.

  The present invention has been made in view of the above points, and an object thereof is to provide an electrophotographic image forming apparatus capable of reliably identifying a used process cartridge and a process cartridge used therefor. .

In the electrophotographic image forming apparatus for forming an image on a recording medium, a typical means in the present invention for solving the above-mentioned problem is that the camshaft rotates to rotate the first position and the first position. A cam member capable of taking a second position retracted from a position, and a process cartridge detachably mounted on a main body of the electrophotographic image forming apparatus, the electrophotographic photosensitive drum, and the electrophotographic photosensitive member A developing roller that contacts the drum and develops the electrostatic latent image formed on the electrophotographic photosensitive member, a first frame that supports the electrophotographic photosensitive drum, and the developing roller. A second frame movably coupled to the first frame, wherein the cam member abuts the cam member when the cam member is positioned at the first position, and the electrophotographic photosensitive drum and the With developing roller A process cartridge having a second frame having a cam engaging portion for receiving a separating force from the cam member; a protrusion protruding from the second frame; and the apparatus when the process cartridge has reached the end of its life when the control means provided in the main body is determined, the pre-Symbol protrusions a lever member to plastically deform or break, provided on the cam shaft coaxially, the cam forces the cam member is the separation When the camshaft rotates forward to give to the engaging portion, the camshaft is elastically deformed by contacting the projecting portion, and when rotating reversely, the projecting portion does not elastically deform even if the camshaft contacts the projecting portion. the and having a lever member that is configured to plastically deform or break.

According to the present invention, the lever member that plastically deforms or breaks the protrusion provided on the process cartridge that has reached the end of its life is coaxial with the cam shaft that rotates the cam member for contacting and separating the photosensitive drum and the developing roller. Provided above. As a result, a mechanism for warning the life of the cartridge can be easily configured without significantly increasing the number of parts. In addition, the electrophotographic image forming apparatus can be reduced in size.

  Next, an electrophotographic image forming apparatus (hereinafter referred to as “image forming apparatus”) and a process cartridge (hereinafter referred to as “cartridge”) used therefor according to an embodiment of the present invention will be described with reference to the drawings.

[First Embodiment]
The image forming apparatus and cartridge according to the first embodiment will be described with reference to FIGS.

{Overall configuration of image forming apparatus and cartridge}
First, the overall configuration of the image forming apparatus will be described together with the image forming operation with reference to FIG. FIG. 3 is a schematic cross-sectional explanatory diagram of the image forming apparatus.

  The image forming apparatus of this embodiment conveys a recording medium to the image forming unit. Then, an image is formed on a recording medium by an electrophotographic method by an image forming unit. In the image forming unit, four image forming units are arranged, and developer images of different colors are sequentially transferred from an electrophotographic photosensitive drum (hereinafter referred to as “photosensitive drum”) to a recording medium to obtain a color. The image is recorded.

  The four cartridges 20 (20Y, 20M, 20C, and 20K) form toner images of yellow (Y), magenta (M), cyan (C), and black (K) in order from the bottom. The configuration is the same except that the colors are different. That is, in each of the cartridges 20Y, 20M, 20C, and 20K, the charging unit 2, the developing unit 4, and the cleaning unit 5 are disposed around the photosensitive drum 1. Then, the surface of the rotating photosensitive drum 1 is uniformly charged by the charging roller 2, and an electrostatic latent image is formed by irradiating the exposure apparatus 3 with laser light corresponding to the image signal. The electrostatic latent image formed on the photosensitive drum 1 is visualized by the developing unit 4 using a developer.

  A recording medium conveyance belt 6 is disposed so as to be in contact with each photosensitive drum 1. The conveying belt 6 is an endless belt that is stretched around a driving roller 7a, a driven roller 7b, and a tension roller 7c, and rotates in the direction of an arrow d according to an image forming operation when the driving roller 7a rotates. A transfer roller 8 is disposed at a position facing each photosensitive drum 1 with the conveyance belt 6 interposed therebetween.

  When forming an image, a sheet as a recording medium is fed from a cassette 9 by a feed roller 10 so as to synchronize with the formation of a developer image by the cartridges 20Y, 20M, 20C, and 20K. Then, the sheet is conveyed by being attracted to the conveyance belt 6 that rotates in the direction of arrow d by applying a bias to the adsorption roller 11. Then, the developer image on the photosensitive drum 1 is transferred to the sheet by applying a bias to the transfer roller 8, and the sheet on which the color image is formed by superimposing the color developer images is conveyed to the fixing unit 12 to fix the toner. After that, it is discharged to the discharge unit 13.

  Note that the image forming apparatus according to the present embodiment can form not only the full-color image operation but also a monochrome image. In the case of forming a monochrome image, only the transfer roller 8 of the black cartridge 20K is brought into contact with the conveyance belt 6, and the other transfer rollers 8 of the yellow, magenta, and cyan cartridges 20Y, 20M, and 20C are conveyed to the conveyance belt 6. Separate from. A monochrome image is obtained by transferring only the black image formed by the black cartridge 20K to the sheet conveyed by the conveyance belt 6 onto the sheet.

  In the present embodiment, the cartridges 20Y, 20M, 20C, and 20K are detachable from the apparatus main body 100. When the cartridges 20Y, 20M, 20C, and 20K are detachable from the cartridge mounting portion 104 provided in the apparatus main body 100, when the member such as the photosensitive drum 1 reaches the end of its life or when the toner is used up. It is easy to replace a cartridge that has reached the end of its service life.

  The cartridges 20Y, 20M, 20C and 20K are provided with a developing roller 4a as a developing means 4 for supplying toner to the photosensitive drum 1. The developing roller 4 a has a magnet inside and rotates in contact with the photosensitive drum 1 to supply toner corresponding to the electrostatic latent image formed on the photosensitive drum 1.

Next, the configuration of the cartridge 20 will be described with reference to FIG. Cartridge 20
It comprises a photosensitive drum 1, a charging roller 2, a first frame 61 that supports the cleaning means (5a, 5b), and a second frame 50 that supports the developing means (4a to 4e). Here, the blade 5 a serving as a cleaning unit is for removing the developer remaining on the photosensitive drum 1. Then, the developer removed by the blade 5a is accommodated in the removed developer accommodating portion 5b which is a cleaning means. The developing means includes a developing roller 4a that supplies the developer to the photosensitive drum 1, a blade 4c that regulates the amount of the developer on the peripheral surface of the developing roller 4a, and a supply roller 4b that conveys the developer to the developing roller 4a. The storage unit 4e stores the developer, and the transport member 4d transports the developer from the storage unit 4e to the supply roller 4b.

  The first frame 61 and the second frame 50 are coupled so as to be rotatable (movable) at a rotation center 50b provided in the second frame 50. Further, the second frame 50 has a separation cam (hereinafter referred to as “cam”) 34 provided in the apparatus main body 100 when rotated in the direction of arrow a from the retracted position (second position). It has a cam engaging portion 50a that abuts. At that time, the cam engaging portion 50a abuts on the cam surface 34a of the cam 34, whereby the second frame 50 rotates about the rotation center 50b in the direction of the arrow c. Accordingly, the developing roller 4 a supported by the second frame 50 is separated from the photosensitive drum 1. In the present embodiment, the position of the cam 34 for separating the developing roller 4a and the photosensitive drum 1 is defined as a separation position (first position).

{Developing member separation means}
At the time of image formation, the developing roller 4a is biased so as to contact the photosensitive drum 1 by a biasing spring (not shown). However, if the surface of the photosensitive drum 1 is constantly urged by the developing roller 4a, a load is always applied to the peripheral surface of the photosensitive drum 1, which is not preferable. In view of this, in the image forming apparatus of the present embodiment, a developing member separating unit is provided to enable the developing roller 4a to be separated from the photosensitive drum 1 during non-image formation. Next, the configuration and operation of the developing member separating means will be described.

  In the cartridge 20 in the standby state, the developing roller 4a is separated from the photosensitive drum 1. At that time, the cam 34 is located at the separated position. When the image forming state is changed from the standby state, the developing roller 4a is brought into contact with the photosensitive drum 1 by rotating the cam by 180 ° and moving from the separated position to the retracted position. Then, when the image formation is completed, the state shifts to the standby state, and the cam 34 is rotated again by 180 ° to operate so that the developing roller is separated.

  That is, the photosensitive drum 1 and the developing roller 4a in contact with each other are separated by rotating the cam 34 as a cam member by 180 °. Further, the photosensitive drum 1 and the developing roller 4a in a separated state are configured to contact each other by rotating the cam 34 by 180 °.

  As shown in FIG. 4, the drive transmission control for rotating the cam 34 by 180 ° is controlled by a pair of missing gears and a solenoid. That is, when the image is formed, the input gear 21 that is rotated by the driving force from the driving motor 102 (see FIG. 3) that is a driving means rotates idly facing the missing tooth portion of the missing gear pair that can mesh therewith. The transmission is interrupted there. The toothless gear pair is composed of three parts: a first toothless gear 23, a second toothless gear 22, and a spring 24 (here, a compression spring), and the locking claw 25 is coaxial with the second toothless gear 22. They are arranged in parallel. The second toothless gear 22 is shaft-fitted to the rotating shaft of the first toothless gear 23, and the thrust direction of the second toothless gear 22 is restricted by a locking claw 25.

  The second toothless gear 22 is urged in one direction via the first toothless gear 23 and the spring 24 in the rotational direction, but a predetermined rotational phase is determined. The state of FIG. 5 shows a state where the locking claw 25 in the second toothless gear 22 is regulated by the flapper 26a of the solenoid 26 that is the driving means. Further, the rotation of the first toothless gear 23 is stopped by two bosses 30 installed on the first toothless gear 23, a spring 27 and a cam lever 28 for applying an urging force thereto. At this time, the second toothless gear 22 and the first toothless gear 23 are stationary with the spring force stored in the spring 24 therein.

  When rotating the cam 34, the flapper 26a is operated to release the locking claw 25 from being locked. As a result, the second partial gear 22 starts rotating by the spring force of the spring 24 incorporated between the first partial gear 23 and the second partial gear 22 rotates to cause the first partial gear. Both gears engage at a phase determined to cover the 23 missing teeth. For this reason, the driving of the pair of toothless gears and the input gear 21 is coupled, and the input gear 21 that transmits the driving force from the drive motor 102 meshes with the first toothless gear 23 from the second toothless gear 22. Driving force is transmitted.

When the pair of toothless gears make a round, the flapper 26a is engaged with the locking claw 25, and the rotation drive of the second toothless gear 22 is stopped. At this time, since the first toothless gear 23 meshes with the input gear 21, it continues to be driven, and the spring 24 between the second toothless gear 22 is compressed and the spring force is stored. The last one tooth just before the input gear 21 reaches the missing tooth portion of the first missing gear 23 must rotate against the compressive force of the spring 24 between the second missing gear 22. should not. Therefore, in this embodiment arranged two bosses 30 on the first segment gear 23, it urges the boss 30 coming just before the toothless portion by the cam lever 28 is urged to spring 27 which is separately arranged Then rotate the first toothless gear 23 quickly. As a result, the input gear 21 stops at the center of the missing tooth portion of the missing gear pair, and returns to the state shown in FIG. In this way, the first partial gear 23 is rotated once by driving the flapper 26a.

On the other hand, the first output gear 31 fitted to the first toothless gear 23 and the second output gear fitted to the cam shaft 32 having a double gear ratio to the first output gear 31 and the first output gear 31 driven simultaneously. 33 is driven, the first output gear 31 by one rotation rotates the second output gear 33 is 180 °, the cam 3 4 rotates 180 °, the development separation operation is performed. That is, as shown in the block diagram of FIG. 11, the cam 34 controls the rotation of the cam 34 by operating the drive motor and solenoid 26, which are drive means, by the main body control means 101 provided in the apparatus main body 100. .

{Cartridge life warning means}
The image forming apparatus of the present embodiment is configured to leave a trace on the cartridge itself when the cartridge 20 reaches the end of its life. Next, a configuration for that purpose will be described.

  Here, the life of the cartridge 20 is the state in which the developer in the developer storage portion 4e shown in FIG. 10 is exhausted, the state in which the removed developer storage portion 5b is full, the photosensitive drum 1, the development. The roller 4a, the charging roller 2, the blade 5a and the like are in a worn state. A state in which the developer in the developer storage portion 4e runs out and a state in which the removed developer storage portion 5b is full are detected by a sensor (not shown) that is a life detection means provided in the apparatus main body 100. . Further, the wear of the photosensitive drum 1 and the like is detected by reading information stored in the memory 70 provided in the cartridge 20 by a reading member (not shown) which is a life detecting means. The signal detected by the life detecting means is transmitted to the main body control means 101 as shown in FIG. Then, the main body control means 101 determines whether or not the detected signal has reached a predetermined value as shown in the flowchart of FIG. When the main body control means 101 reaches a predetermined value, the cartridge 20 has reached the end of its life and the lever 35 is operated. In the present embodiment, the lever 35 is operated by the clutch 36. Further, the display unit (not shown) displays that the cartridge 20 has reached the end of its life.

  As shown in FIG. 1, the cartridge 20 of the present embodiment is provided with a rib 38 that is a cantilever projecting member that can be irreversibly deformed by an action portion described later. The rib 38 is composed of a member that is plastically deformed when pressed. FIG. 1 is a view of the cartridge 20 as viewed from the direction of the arrow V in FIG. The rib 38 is provided at a position substantially overlapping with the cam engaging portion 50a in the longitudinal direction of the cartridge 20.

  On the other hand, a trigger lever 35 as a lever member for deforming the rib 38 is provided on the same axis as the cam shaft 32 to which the cam 34 is attached. Further, the driving force of the cam shaft 32 is transmitted to the trigger lever 35 via an electromagnetic clutch 36 as a clutch means. The trigger lever 35 does not rotate when the electromagnetic clutch 36 is OFF, and the trigger lever 35 rotates when the electromagnetic clutch 36 is ON.

  Further, in the image forming apparatus, when the main body control means determines that the cartridge 20 has reached the end of its life by the above-mentioned life detection means, the fact is displayed on the display unit 103 of the apparatus main body 100.

  When the main body control means 101 determines that the cartridge 20 has reached the end of its life based on the signal detected by the cartridge life detection means, it is coaxial with the cam shaft 32 for operating the cam 34 as shown in FIG. The provided trigger lever 35 is operated. Thereby, the trigger lever 35 irreversibly deforms the rib 38.

  Specifically, the electromagnetic clutch 36 is normally OFF and no driving force is transmitted to the trigger lever 35. However, when the main body control means 101 determines that the cartridge 20 has reached the end of its life, the main body control means 101 turns on (excites) the electromagnetic clutch 36 as shown in FIG. As a result, the idle trigger lever 35 rotates in the direction of arrow a shown in FIG. Then, the trigger lever 35 contacts the rib 38 provided on the cartridge 20, and the rib 38 is bent and plastically deformed. For this reason, even if the cartridge is removed from the apparatus main body 100, it can be easily recognized that the cartridge has reached the end of its life because the rib 38 is bent. Therefore, it is possible to prevent erroneous mounting of a cartridge that has reached the end of its life without erroneously checking whether or not the cartridge placed alone has reached the end of its life.

  In addition, as shown in FIG. 1, it is surrounded by the wall 37 so that a user cannot access the rib 38. The wall 37 is provided with a slit 37a having a width that allows the trigger lever 35 to pass therethrough. In other words, the rib 38 is prevented from being deformed by the user by mistake.

  Further, the ribs 38 may have not only a cantilever support shape but also a both-end support shape as shown in FIG. The central part of the rib 38 is thinner or thinner than the other parts. That is, the rib 38 may be ruptured when the trigger lever 35 abuts. In this way, when the trigger lever 35 contacts the rib 38, the drive motor 102 does not need a large load. .

[Second Embodiment]
Next, an apparatus according to the second embodiment will be described with reference to FIG. Note that the basic configuration of the apparatus of the present embodiment is the same as that of the first embodiment described above, and thus a duplicate description is omitted. Only the configuration that is a feature of the present embodiment will be described here. Moreover, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above.

  In the first embodiment described above, the trigger lever 35 is operated by rotating the cam shaft 32 in the same direction as the direction in which the cam 34 is rotated. However, in the second embodiment, the trigger lever 35 is operated by rotating the cam shaft 32 in the direction opposite to the direction in which the cam 34 is operated.

  Specifically, a trigger lever 35 on the camshaft 32 is connected as a clutch means via a one-way clutch 40 that transmits torque to the camshaft 32 only in one direction of rotation.

  When the cam shaft 32 rotates forward in the direction of arrow a, which is the direction in which the cam 34 is operated, the driving force is not transmitted from the one-way clutch 40 to the trigger lever 35. That is, the cam 34 comes into contact with the rib 38 and stops without being deformed. When the main body control means 101 determines that the cartridge 20 has reached the end of its life, the main body control means 101 reversely rotates the cam shaft 32 in the direction of arrow b as shown in the block diagram of FIG. 13 and FIG. . Due to this reverse rotation, the driving force is transmitted to the trigger lever 35 via the one-way clutch 40. Then, the trigger lever 35 comes into contact with the rib 38 provided on the cartridge 20, and the rib 38 is bent and plastically deformed.

  As described above, by using the one-way clutch as the clutch means, it is possible to obtain the same effect as the above-described embodiment while reducing the cost by forward and reverse rotation of the cam shaft 32.

[Third Embodiment]
Next, an apparatus according to a third embodiment will be described with reference to FIG. Note that the basic configuration of the apparatus of the present embodiment is also the same as that of the first embodiment described above, and a duplicate description is omitted. Here, only the configuration that is a feature of the present embodiment will be described. Moreover, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above.

  This embodiment is the same as the second embodiment described above, but uses a ratchet mechanism as a one-way clutch. That is, the trigger lever 35 is connected to the camshaft 32 via a ratchet mechanism. The ratchet mechanism is composed of three parts: a ratchet cam 41, a trigger lever 35, and a cam pressing spring 42.

  The ratchet cam 41 is movable in the thrust direction with respect to the cam shaft 32, and is fixed in the radial direction. That is, the ratchet cam 41 is biased to the trigger lever 35 by the cam pressing spring 42. The trigger lever 35 is fixed to the camshaft 32 in the thrust direction and is rotatably supported in the radial direction.

  When the cam shaft 32 rotates in the forward direction, the inclined cam 43 rotates simultaneously with the cam shaft 32, and the trigger lever 35 rotates at the same time. However, when the trigger lever 35 hits the rib 38, the ratchet cam 41 and the cam surface 43 of the trigger lever 35 slide due to the load, and run on the slope against the spring force of the cam pressing spring 42 and idle. For this reason, the trigger lever 35 stops in a state where it abuts against the rib 38 without plastically deforming or breaking the rib 38.

  When the main body control means 101 determines that the cartridge 20 has reached the end of its life, the main shaft control means 101 causes the cam shaft 32 to reversely rotate in the direction of arrow b as shown in the block diagram of FIG. 13 and FIG. To do. As a result, the ratchet cam 41 and the vertical cam surface 44 of the trigger lever 35 are engaged, and the driving force is transmitted from the ratchet cam 41 to the trigger lever 35. Then, the trigger lever 35 comes into contact with the rib 38 and deforms the rib 38 irreversibly. Even if it does in this way, the effect similar to 2nd Embodiment mentioned above can be acquired.

[Fourth Embodiment]
Next, an apparatus according to a fourth embodiment will be described with reference to FIG. The basic configuration of the apparatus according to the present embodiment is also the same as that of the first embodiment described above, and a duplicate description is omitted. Here, only the configuration that is a feature of the present embodiment will be described. Moreover, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above.

  This embodiment is the same as the second embodiment described above, but uses a tightening spring as a one-way clutch. That is, as shown in FIG. 8, the trigger lever 35 provided on the cam shaft 32 is attached to the cam shaft 32 via the restricting spring 45.

  That is, one end 45 a of the restricting spring 45 is fixed to the cam shaft 32. The inner diameter portion 45 c of the narrowing spring 45 is fitted to the trigger lever 35. The other end side 45 b of the restricting spring 45 is attached to be hooked on the trigger lever 35. Further, the trigger lever 35 is attached to the cam shaft 32 so as to be fixed in the thrust direction and freely rotatable in the radial direction.

  When the cam shaft 32 rotates in the direction a, the constricting spring 45 rotates simultaneously with the cam shaft 32, and the trigger lever 35 rotates at the same time. However, when it comes into contact with the rib 38, the tightening spring 45 spreads to the loose side due to the load, and the camshaft 32 and the trigger lever 35 idle. The trigger lever 35 is stopped in contact with the rib 38 without causing the rib 38 to be plastically deformed or broken.

  Next, when the main body control means 101 determines that the cartridge 20 has reached the end of its life, the main body control means 101 reverses the cam shaft 32 in the direction of arrow b as shown in the block diagram of FIG. 13 and FIG. Rotate. Thereby, when the bent portion of the narrowing spring 45 is caught by the trigger lever 35, the trigger lever 35 rotates in synchronization with the cam shaft 32. When a load is applied, the tightening spring 45 tightens the body of the trigger lever 35 to transmit the torque and transmit the driving force, and the trigger lever 35 rotates in the direction of arrow b. Then, the rib 38 is irreversibly deformed. As described above, when the tightening spring is used as the one-way clutch, the used cartridge can be recognized with a simpler configuration.

[Fifth Embodiment]
Next, an apparatus according to a fifth embodiment will be described with reference to FIG. Note that the basic configuration of the apparatus of the present embodiment is also the same as that of the first embodiment described above, and a duplicate description is omitted. Here, only the configuration that is a feature of the present embodiment will be described. Moreover, the same code | symbol is attached | subjected to the member which has the same function as embodiment mentioned above.

  In the present embodiment, the trigger lever 35 is composed of an elastic member, and this is fixed to the cam 34 shaft 32. The elastic characteristic of the trigger lever 35 is elastically deformed when the cam 34 shaft 32 rotates forward to operate the developing member separating means. On the other hand, when the cam 34 shaft 32 rotates in the reverse direction, the trigger lever 35 is not elastically deformed.

  For this reason, when the camshaft rotates in the direction a, the trigger lever 35 is elastically deformed with the tip end portion 46 contacting the rib 38. Therefore, the rib 38 is not plastically deformed or broken. On the other hand, when the main body control means 101 determines that the cartridge 20 has reached the end of its life, the main body control means 101 reversely rotates the camshaft 32 in the direction of arrow b as shown in the block diagram of FIG. 13 and FIG. Let Then, the distal end portion 46 does not bend, and the end surface of the distal end portion 46 abuts against the rib 38 and is plastically deformed or broken.

  With this configuration, it is possible to issue a cartridge life warning without using a clutch as in the above-described embodiment.

It is the schematic of the cartridge lifetime detection mechanism using an electromagnetic clutch. It is the schematic of the example from which the shape of a lifetime detection member differs. 1 is an overall cross-sectional explanatory diagram of an image forming apparatus. It is a schematic diagram of a development separation mechanism. FIG. 5 is a schematic view of a developing separation mechanism as viewed from the reverse of FIG. 4. It is the schematic of the cartridge lifetime detection mechanism using the one-way clutch which concerns on 2nd Embodiment. It is the schematic of the cartridge lifetime detection mechanism using the ratchet mechanism as a one-way clutch which concerns on 3rd Embodiment. It is the schematic of the cartridge lifetime detection mechanism using the spring clutch mechanism as a one-way clutch which concerns on 4th Embodiment. It is the schematic of the cartridge lifetime detection mechanism which used the elastic characteristic of material for the cam member which concerns on 5th Embodiment. It is sectional drawing of the process cartridge which concerns on embodiment. It is a block diagram concerning a 1st embodiment. It is a flowchart concerning an embodiment. It is a block diagram concerning a 5th embodiment from a 2nd embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Photosensitive drum 2 ... Charging roller 3 ... Exposure apparatus 4 ... Developing means 4a ... Developing roller 5 ... Cleaning means 6 ... Recording medium conveyance belt 7a ... Drive roller 7b ... Drive roller 7c ... Tension roller 8 ... Transfer roller 9 ... Cassette
10 ... Feed roller
11… Suction roller
12… Fixing means
13… discharge section
20Y, 20M, 20C, 20K ... Image forming means
21… Input gear
22 ... 2nd toothless gear
23 ... 1st toothless gear
24… Spring
25… locking claw
26… Solenoid flapper
27… Spring
28… Cam lever
30… Boss
31 ... 1st output gear
32… Cam 34 axis
33 ... 2nd output gear
34… Development separation cam
35… Trigger lever
36… Electromagnetic clutch
37… wall
38… Life warning material
39… Slit shape
40… one-way clutch
41… Ratchet cam
42… Cam pressing spring
44… Cam surface
45… Tightening spring

Claims (2)

In an electrophotographic image forming apparatus for forming an image on a recording medium,
A cam member that rotates by rotation of the camshaft and can take a first position and a second position retracted from the first position;
A process cartridge that is detachably attached to the main body of the electrophotographic image forming apparatus, the electrophotographic photosensitive drum, and an electrostatic formed on the electrophotographic photosensitive member in contact with the electrophotographic photosensitive drum A developing roller for developing a latent image, a first frame that supports the electrophotographic photosensitive drum, and a second frame that supports the developing roller and is movably coupled to the first frame When the cam member is positioned at the first position, the cam engagement receives the force from the cam member that contacts the cam member and separates the electrophotographic photosensitive drum from the developing roller. A process cartridge having a second frame having a portion and a protruding portion protruding from the second frame,
Wherein when the control means process cartridge provided in the apparatus main body has reached its life is determined, the pre-Symbol protrusions a lever member to plastically deform or break, provided on the cam shaft coaxially, The cam member is elastically deformed by coming into contact with the protrusion when the cam shaft rotates in order to apply the separating force to the cam engaging portion, and is brought into contact with the protrusion when rotating in the reverse direction. A lever member configured to plastically deform or break the protrusion without elastically deforming ,
Electrophotographic image forming apparatus characterized by having a. 2. The electrophotographic image forming apparatus according to claim 1, wherein the protrusion is surrounded by a wall having a slit through which the lever member can pass.

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