JP2022084516A - Photoreceptor unit - Google Patents

Abstract

To prevent, in a state in which a photoreceptor and an electrifying roller are separated from each other with the engagement between an engagement part of a separation member and a photoreceptor gear, the separation state between the photoconductor and the electrifying roller from being unintentionally cancelled, even when a force is applied in which the engagement part of the separation member moves in a direction separating from the photoreceptor gear.SOLUTION: A photoreceptor unit comprises: a separation member for separating an electrifying roller and a photoreceptor from each other; a guide unit that, in a state in which an engagement part of the separation member and a gear are engaged with each other, guides an electrifying roller bearing member urged by an urging member to separate the electrifying roller from the photoreceptor, and in a state in which the engagement part and the gear are not engaged with each other, guides the electrifying roller bearing member urged by the urging member to bring the electrifying roller into contact with the photoreceptor; and a frame that supports the photoreceptor. In a state in which the engagement part and the gear are engaged with each other, when the distance between the electrifying roller bearing member urged by the urging member and the frame is A, and the length of the engagement between the engagement part and the gear is B, A<B is satisfied.SELECTED DRAWING: Figure 15

Description

The present invention relates to a photoconductor unit that can be attached to an image forming apparatus using an electrophotographic process.

An electrophotographic image forming apparatus that employs a method of exchanging a photoconductor unit in which a photoconductor and a charging roller that charges the photoconductor is integrated is known in order to facilitate maintenance. Further, in an image forming apparatus that employs such a method, a contact charging method is often adopted in which a charging roller having an elastic layer is brought into contact with a photoconductor by a urging force such as a spring to charge the photoconductor.

In such a contact charging method, if the photoconductor unit is left in contact with the charging roller for a long period of time, the portion of the charging roller that is in contact with the photoconductor is deformed and an image is formed. In some cases, image defects may occur.

In order to suppress such image defects, it is known that the photoconductor unit is shipped by sandwiching a spacer between the photoconductor and the charging roller, the spacer is removed, and then the photoconductor unit is attached to the main body of the image forming apparatus. Has been done.

However, in such a configuration, there is a problem that it takes time and effort for the user to remove the spacer when the photoconductor unit is attached to the main body of the image forming apparatus.

Therefore, in Patent Document 1, when the photoconductor unit is attached to the main body of the image forming apparatus, the user does not remove the spacer, and the charged rollers separated by the rotation of the photoconductor come into contact with the photoconductor. The configuration is disclosed. Specifically, the photoconductor and the charging roller are in a state where the fan-shaped engaging portion provided at the tip of the separating member fitted to the rotating shaft of the charging roller is engaged with the photoconductor gear provided coaxially with the photoconductor. It is configured to separate from. When the separating member is rotated by rotating the photoconductor, the photoconductor gear and the separating member are disengaged, so that the photoconductor and the charging roller come into contact with each other.

However, in the configuration of Patent Document 1, the photoconductor rotates due to vibration applied to the photoconductor unit from the time the photoconductor unit is shipped until it is mounted on the image forming apparatus main body, for example, during transportation. .. As a result, the separating member may come off due to the rotation of the photoconductor, and the photoconductor and the charging roller may unintentionally come into contact with each other.

Therefore, Patent Document 2 describes a configuration in which the engaging portion of the separating member is engaged with the gear of the photoconductor and the engaging portion is pressed against the gear when the photosensitive member and the charging roller are separated from each other. According to this configuration, since the engaging portion is pressed against the gear, the gear is difficult to rotate.

Japanese Unexamined Patent Publication No. 11-9532 Japanese Unexamined Patent Publication No. 2016-133775

However, before the photoconductor unit is attached to the main body of the image forming apparatus, strong vibration may be applied to the photoconductor unit, and the separating member may move together with the charging roller in a direction away from the photoconductor. As a result, in the configuration of Cited Document 2, when a force is applied together with the charging roller to move the separating member in the direction away from the photoconductor, the engaging portion can rotate freely when the engaging portion is separated from the gear of the photoconductor. There was a risk that the separated member would rotate and the separated state would be released.

Therefore, an object of the present invention is a direction in which the engaging portion of the separating member is separated from the photoconductor gear in a state where the photoconductor and the charging roller are separated by the engagement between the engaging portion of the separating member and the photoconductor gear. It is an object of the present invention to provide a photoconductor unit capable of suppressing the unintentional elimination of the separated state between the photoconductor and the charging roller even when a moving force is applied to the photoconductor.

The present invention is a photoconductor unit that can be attached to an image forming apparatus, and is a rotatable photoconductor, a rotatable charging roller that contacts the photoconductor and charges the photoconductor, and rotation of the charging roller. A charging roller bearing member attached to a shaft and rotatably supporting the charging roller, an urging member provided on the charging roller bearing member to urge the charging roller toward the photoconductor, and the photoconductor. It has a gear provided at an end portion in the direction of the rotation axis and an engaging portion provided on the rotation shaft of the charging roller and engaged with the gear, for separating the charging roller and the photoconductor. In a state where the separating member and the engaging portion and the gear are engaged, the charging roller bearing member guided by the urging member so that the charging roller is separated from the photoconductor, and A guide portion for guiding the charged roller bearing member urged by the urging member so that the charging roller comes into contact with the photoconductor in a state where the engaging portion and the gear are not engaged, and the above. A frame that supports the photoconductor is provided, and the distance between the charged roller bearing member urged by the urging member and the frame in a state where the engaging portion and the gear are engaged is A. When the length at which the engaging portion is engaged with the gear is B, it is characterized in that A <B is satisfied.

According to the present invention, in a state where the photoconductor and the charging roller are separated by the engagement between the engaging portion of the separating member and the photoconductor gear, the engaging portion of the separating member moves in the direction away from the photoconductor gear. Even when the force is applied, it is possible to prevent the state of separation between the photoconductor and the charging roller from being unintentionally eliminated.

The schematic block diagram of the image forming apparatus which concerns on 1st Embodiment. Schematic sectional view of the drum unit according to the first embodiment. The partial perspective view which shows the contact state of the drum unit which concerns on 1st Embodiment by omitting the regulation part. The partial perspective view which shows the contact state of the drum unit which concerns on 1st Embodiment by omitting a regulation part, a separation member and a frame. The partial perspective view which shows the separated state of the drum unit which concerns on 1st Embodiment by omitting the regulation part. The partial perspective view which shows the separated state of the drum unit which concerns on 1st Embodiment by omitting a regulation part and a frame. FIG. 3 is a schematic cross-sectional view showing (a) a separated state and (b) a state in which the separated state is released, respectively, of the separating member according to the first embodiment. The partial perspective view which shows the separated state of the drum unit which concerns on 1st Embodiment. A partial perspective view showing (a) a separated state of the drum unit according to the first embodiment without a frame, and (b) a partial perspective view showing a photosensitive drum and a frame. (A) Partial side view showing a separated state of the drum unit according to the first embodiment, (b) XX sectional view of (a). In the first embodiment, when the abutting portion abuts against the abutting portion, (a) the direction of the torque acting is (b) the urging direction acting on the separating member and the normal vector at the abutting portion. The same figure as in FIG. 10 (b) which shows the relationship of each. It is a perspective view which showed the separation holding part which is the structure of this invention in 1st Embodiment. It is a perspective view which showed the separation holding part which is the structure of this invention in 1st Embodiment. It is sectional drawing which showed the modification of this invention. It is sectional drawing which showed the modification of this invention.

<First Embodiment>
The first embodiment of the present invention will be described with reference to FIGS. 1 to 11. First, the schematic configuration of the image forming apparatus of this embodiment will be described with reference to FIG.

[Image forming device]
The image forming apparatus 1 is a tandem type image forming apparatus adopting an intermediate transfer method capable of forming a full-color image by using an electrophotographic method. That is, the image forming apparatus 1 includes an image forming unit 10 of each color of Y (yellow), M (magenta), C (cyan), and K (black), and the image forming unit 10 of each color is attached to the intermediate transfer belt 61. It is a so-called tandem type configuration in which they are arranged side by side in the rotation direction. The configuration and operation of each image forming unit 10 are substantially the same except that the color of the toner used is different.

The image forming unit 10 has a photosensitive drum 11 which is a cylindrical electrophotographic photosensitive member (photoreceptor). The photosensitive drum 11 is rotationally driven at a process speed (peripheral speed) of 100 mm / sec by transmitting a driving force from a driving means (not shown) provided in the apparatus main body 1a. In the image forming unit 10, a charging roller 12, a developing device 14, a primary transfer roller 17, and a drum cleaning device 15 are arranged in order around the photosensitive drum 11 along the rotation direction thereof. An exposure apparatus 16 is arranged below each image forming unit 10. Further, the image forming apparatus 1 has an intermediate transfer belt 61 formed of an endless belt body as an intermediate transfer body so as to be in contact with the photosensitive drum 11 of each image forming unit 10.

The charging roller 12 as a charging means is a rotatable roller-shaped charging member, which is arranged so as to abut on the photosensitive drum 11 to charge the surface of the photosensitive drum 11. The exposure device (laser scanner device) 16 as an exposure means exposes the surface of the charged photosensitive drum 11 to form an electrostatic latent image on the surface of the photosensitive drum 11.

The developing apparatus 14 as a developing means contains toner as a developing agent inside, and develops an electrostatic latent image formed on the photosensitive drum 11 as a toner image using the toner. Such a developing device 14 has a developing sleeve 14a as a developing agent carrier that carries toner and conveys it to a portion (development position) facing the photosensitive drum 11. The developing sleeve 14a is rotationally driven.

The primary transfer roller 17 as the primary transfer means is a roller-shaped primary transfer member, and the toner image formed on the photosensitive drum 11 is primarily transferred to the intermediate transfer belt 61. The drum cleaning device 15 cleans the transfer residual toner and the like remaining on the photosensitive drum 11 after the primary transfer.

The intermediate transfer belt 61 is formed endlessly with a dielectric resin such as polyimide. The intermediate transfer belt 61 is hung around a plurality of support rollers (tension rollers) with a predetermined tension. The above-mentioned primary transfer roller 17 is arranged at a position facing each photosensitive drum 11 on the inner peripheral surface side (back surface side) of the intermediate transfer belt 61. The primary transfer roller 17 is pressed against the photosensitive drum 11 via the intermediate transfer belt 61, and forms a primary transfer portion (primary transfer nip portion) N1 in which the intermediate transfer belt 61 and the photosensitive drum 11 come into contact with each other. The primary transfer roller 17 is driven and rotated as the intermediate transfer belt 61 rotates.

Further, a secondary transfer roller 35, which is a roller-shaped secondary transfer member as a secondary transfer means, is arranged at a position facing the secondary transfer facing roller 62 on the outer peripheral surface side (surface side) of the intermediate transfer belt 61. ing. The secondary transfer roller 35 is pressed against the secondary transfer facing roller 62 via the intermediate transfer belt 61, and the secondary transfer portion (secondary transfer nip portion) in which the intermediate transfer belt 61 and the secondary transfer roller 35 come into contact with each other. ) Forming N2. The toner image transferred to the intermediate transfer belt 61 is secondarily transferred to the recording material P by the secondary transfer unit N2.

Further, a belt cleaning device 70 as an intermediate transfer body cleaning means is arranged at a position facing the tension roller 64 on the outer peripheral surface side of the intermediate transfer belt 61. The belt cleaning device 70 cleans the transfer residual toner and the like remaining on the intermediate transfer belt 61 after the secondary transfer.

Next, the image forming operation will be described. At the time of image formation, the surface of the photosensitive drum 11 that is rotationally driven is uniformly charged to a predetermined potential of a predetermined polarity by the charging roller 12. In the present embodiment, only a DC voltage of -1300V is applied to the charging roller 12 from a high-voltage power supply (charged power supply) (not shown) to generate a discharge on the surface of the photosensitive drum 11, whereby the surface of the photosensitive drum 11 is generated. Is charged to about -700V.

After the surface of the photosensitive drum 11 is uniformly charged, the surface of the photosensitive drum 11 is scanned and exposed by the exposure apparatus 16 based on the signal of the image information, and an electrostatic latent image (electrostatic image) is obtained on the photosensitive drum 11. Is formed. The image forming apparatus 1 of the present embodiment includes an image reading apparatus 2, and the above-mentioned image information includes image information of a document read by the image reading apparatus 2 and a personal computer connected to the image forming apparatus 1. There is image information sent from an external terminal such as a computer.

The electrostatic latent image formed on the photosensitive drum 11 is developed as a toner image by the developing apparatus 14 using toner as a developing agent. In this embodiment, the normal charge polarity of the toner is negative. At the time of development, a predetermined development voltage (development bias) is applied to the development sleeve 14a from a high-voltage power source as a development power source (not shown). As the development voltage, a vibration voltage in which a DC voltage (DC component) and an AC voltage (AC component) are superimposed is used. Further, toner is supplied to the developing device 14 from a toner bottle 19 as a toner container via a toner transport path (not shown).

The toner image formed on the photosensitive drum 11 is transferred (primary transfer) to the surface of the intermediate transfer belt 61 by the action of the primary transfer roller 17 in the primary transfer unit N1. At this time, the primary transfer roller 17 is subjected to a primary transfer voltage (primary) which is a DC voltage having a polarity opposite to the charging polarity of the toner at the time of development (positive electrode property in this embodiment) from a primary transfer power supply (high voltage power supply) (not shown). Transfer bias) is applied. At the time of forming a full-color image, the above-mentioned operation is performed in each image forming unit 10, and the toner images of each color of yellow, magenta, cyan, and black formed on each photosensitive drum 11 are sequentially superimposed in the middle. It is transferred onto the transfer belt 61. After the transfer, a small amount of transfer residual toner remaining on the photosensitive drum 11 is removed by the drum cleaning device 15 and collected by the collection unit.

On the other hand, the recording materials P are fed one by one from the feeding cassette 20 and conveyed to the resist roller pair 23. The recording material P is, for example, a sheet such as paper or a plastic sheet. After that, the resist roller pair 23 transfers the recording material P between the intermediate transfer belt 61 and the secondary transfer roller 35 in synchronization with the toner image on the intermediate transfer belt 61.

The color toner image on the intermediate transfer belt 61 is transferred (secondary transfer) to the surface of the recording material P by the action of the secondary transfer roller 35 in the secondary transfer unit N2. When the recording material P passes through the secondary transfer unit N2, a DC voltage having a polarity opposite to the charging polarity of the toner during development is applied to the secondary transfer roller 35 from a secondary transfer power supply (high voltage power supply) (not shown). The secondary transfer voltage (secondary transfer bias) is applied. After the transfer, a small amount of residual toner remaining on the intermediate transfer belt 61 is removed and recovered by the belt cleaning device 70 to prepare for the next image formation again.

The toner image transferred onto the recording material P is fixed by being heated and pressed by the nip portion of the heating roller 41 and the pressure roller 42 of the fixing device 40, and is discharged onto the discharge tray 51 by the discharge roller pair 50. Will be done.

[Drum cartridge]
Next, the schematic configuration of the drum cartridge 100 as the photoconductor unit will be described with reference to FIGS. 2 to 4. In the case of the present embodiment, the drum cartridge 100 having the photosensitive drum 11 is detachable from the device main body 1a (FIG. 1) so that it can be replaced by maintenance or the like. For example, the drum cartridge 100 is detachable from the device main body 1a by moving it along the longitudinal direction (rotational axis direction of the photosensitive drum 11) with respect to the device main body 1a.

As shown in FIG. 2, the drum cartridge 100 includes a photosensitive drum 11 as a photoconductor, a charging roller 12, a cleaning roller 13 as a cleaning member, a drum cleaning device 15, a resin separating member 200, and the like. And these are integrally held by the drum container 30 as a frame.

In the drum container 30, the photosensitive drum 11 is rotatably held around a rotation axis via a bearing (not shown). That is, as shown in FIG. 3, the drum container 30 has side walls 30a arranged on both sides of the photosensitive drum 11, charging roller 12, and cleaning roller 13 in the direction of the rotation axis, and connecting portions 30b connecting the side walls 30a on both sides. .. Both ends of the photosensitive drum 11 in the rotation axis direction are rotatably supported on the side walls 30a on both sides in the rotation axis direction via bearings.

Further, the photosensitive drum 11 is provided with a coupling 39 (FIG. 4) for receiving a driving force from a motor as a driving source (not shown) provided in the apparatus main body 1a and rotating while the photosensitive drum 11 is attached to the apparatus main body 1a. Has been done. When the drum cartridge 100 is mounted on the device main body 1a, the coupling 39 is coupled to the coupling provided on the device main body 1a side, and the driving force is transmitted from the motor provided on the device main body 1a.

Further, the drum container 30 is provided with a drum cleaning device 15, which has a cleaning blade 15a, a recovery unit 15b, and a toner transfer screw 38. The cleaning blade 15a is fixed to the drum container 30 and abuts on the surface of the photosensitive drum 11 in the counter direction with respect to the rotation direction β of the photosensitive drum 11 at the time of image formation to clean the surface of the photosensitive drum 11.

Further, the recovery unit 15b is provided in the vicinity of the cleaning blade 15a, and recovers the transfer residual toner removed from the surface of the photosensitive drum 11 by the cleaning blade 15a. The toner transfer screw 38 as a transfer unit conveys the collected toner to the collection unit 15b and conveys it to the outside of the drum cartridge 100. The toner conveyed to the outside of the drum cartridge 100 by the toner transfer screw 38 is collected in a waste toner container (not shown) provided in the apparatus main body 1a.

A gear 36 (FIG. 3, FIG. 3; 4) is provided. That is, the gear 36 is provided on the rotation axis of the photosensitive drum 11 so as to rotate together with the photosensitive drum 11. The gear 36 rotates integrally with the photosensitive drum 11 by inputting a driving force to the photosensitive drum 11 via the coupling 39. The rotational force of the gear 36 is transmitted to the toner transfer screw 38. As a result, the toner transfer screw 38 rotates, and the transfer residual toner collected in the collection unit 15b can be transferred to the outside of the drum cartridge 100.

The charging roller 12 as a charging member is a roller-shaped member having a rotating shaft 12a which is a conductive support (core metal, core material) and one or more elastic layers 12b formed around the rotating shaft 12a. Is. The charging roller 12 is brought into contact with the surface of the photosensitive drum 11 with a predetermined pressing force by a pressure spring 32 (FIG. 4) as a first urging member, and is driven by the rotation of the photosensitive drum 11. And rotate.

A more specific explanation will be given. The charging roller 12 is rotatably supported by the rotating shaft 12a being held by the charging roller bearing 31 as a roller holding portion. Further, the charged roller bearing 31 is slidably supported with respect to the drum container 30. Specifically, the charging roller bearing 31 is slidably guided in the direction toward the rotation axis of the photosensitive drum 11 by the slide guide portion 30c provided in the drum container 30. In the illustrated example, the charging roller bearing 31 is formed with a groove 31a along the slide direction, and when the slide guide portion 30c engages with the groove 31a, the charging roller bearing 31 is formed on the photosensitive drum 11. It is guided in the direction toward the rotation axis.

The charging roller 12 supported by the charging roller bearing 31 is movable along the direction toward the rotation axis of the photosensitive drum 11 on the plane perpendicular to the rotation axis of the photosensitive drum 11. As a result, the charging roller 12 is movably provided at a contact position in contact with the surface of the photosensitive drum 11 and a separated position separated from the surface of the photosensitive drum 11. Then, the charging roller 12 charges the surface of the photosensitive drum 11 by applying a voltage at the contact position.

Further, a pressure spring 32 as a first urging member is provided between the drum container 30 and the charging roller bearing 31. The pressure spring 32 urges the charging roller 12 in the direction toward the rotation axis of the photosensitive drum 11 (the urging direction of the pressure spring 32) on the plane perpendicular to the rotation axis of the photosensitive drum 11. That is, the pressure spring 32 urges the charging roller bearing 31 in the same direction as the sliding direction of the charging roller bearing 31. Therefore, the charging roller 12 is pressed against the photosensitive drum 11 and comes into contact with the photosensitive drum 11. That is, the pressure spring 32 urges the charging roller 12 in the direction from the separated position to the contact position.

The cleaning roller 13 as a cleaning member comes into contact with the charging roller 12 to clean the surface of the charging roller 12. The cleaning roller 13 has a rotating shaft 13a which is a rod-shaped support portion (core metal, core material) and an elastic layer 13b formed around the rotating shaft 13a, and its outer peripheral surface comes into contact with the charging roller 12. It is a roller-shaped member. The cleaning roller 13 is brought into contact with the surface of the charging roller 12 with a predetermined pressing force by a pressure spring 34 (FIGS. 3 and 4) as a second urging member, and is brought into contact with the surface of the charging roller 12 as the charging roller 12 rotates. It follows and rotates.

A more specific explanation will be given. The cleaning roller 13 is rotatably supported by the rotating shaft 13a being supported by the cleaning roller bearing 33. Further, the cleaning roller bearing 33 is slidably supported with respect to the charging roller bearing 31. Specifically, the cleaning roller bearing 33 faces the rotation axis of the charging roller 12 so that the cleaning roller 13 can move along the direction toward the rotation axis of the charging roller 12 on the plane perpendicular to the rotation axis of the charging roller 12. It is configured to be slidable in the direction. In this embodiment, the rotation axis of the charging roller 12 and the rotation axis of the separation member 200, which will be described later, are common.

As a result, the cleaning roller 13 is movably provided at a roller contact position in contact with the surface of the charging roller 12 and a roller separation position separated from the surface of the charging roller 12. Then, the cleaning roller 13 cleans the charging roller 12 at the roller contact position.

Further, a pressure spring 34 as a second urging member is provided between the charging roller bearing 31 and the cleaning roller bearing 33. The pressure spring 34 urges the cleaning roller 13 in a direction (biasing direction) toward the rotation axis of the charging roller 12 on a surface perpendicular to the rotation axis of the charging roller 12. Therefore, the cleaning roller 13 is pressed against the charging roller 12 and comes into contact with the charging roller 12. That is, the pressure spring 34 urges the cleaning roller 13 in the direction from the roller separation position to the roller contact position. In other words, the cleaning roller 13 is supported by the cleaning roller bearing 33 so as to be movable along the urging direction of the pressure spring 34. Further, in the present embodiment, the urging direction by the pressure spring 32 and the urging direction by the pressure spring 34 are substantially the same direction.

Further, the cleaning roller 13 is supported by the charging roller bearing 31 via the cleaning roller bearing 33 and the pressure spring 34. Therefore, as described below, when the charging roller 12 is moved away from the photosensitive drum 11 by the separating member 200, the cleaning roller 13 moves in the moving direction of the charging roller 12 in conjunction with this.

With the above configuration, when the photosensitive drum 11 receives a driving force from a driving source such as a motor provided in the apparatus main body 1a and rotates, the charging roller 12 is driven and rotated by the frictional force with the photosensitive drum 11. Further, when the charging roller 12 rotates, the cleaning roller 13 is driven to rotate due to the frictional force with the charging roller 12. Further, the toner transfer screw 38 receives a driving force (rotational force) from the gear 36 and rotates.

[Separation member]
Next, the separation member 200 will be described with reference to FIGS. 3 to 7. In FIGS. 3 to 7, the regulation unit 300, which will be described later, is omitted. First, using FIGS. 5, 6 and 7 (a), a separation holding configuration is used in which the photosensitive drum 11, the charging roller 12, and the charging roller 12 and the cleaning roller 13 are held apart by the separation member 200. Will be explained.

[Structure of separation holding]
The drum cartridge 100 is provided with a separating member 200 for ensuring a clearance by separating the charging roller 12 and the photosensitive drum 11 and the charging roller 12 and the cleaning roller 13 during transportation for distribution. ing.

The separating member 200 is provided swingably on the rotation axis of the charging roller 12. In the present embodiment, the separating member 200 is provided at both ends of the rotating shaft 12a of the charging roller 12 so as to be swingable with the rotating shaft 12a as a swinging shaft. In other words, the separating member 200 is supported by the charging roller 12 so as to be swingable around the rotation axis of the charging roller 12. Therefore, the separating member 200 can move in conjunction with the movement of the charging roller 12. Since the configurations of the separating members 200 at both ends of the charging roller 12 are the same, the following description will be made with reference to a diagram showing only one side.

The separation member 200 has two separation holding portions 210 and 220 and a swing support portion 230. As described above, the swing support portion 230 is swingably fitted to the rotating shaft 12a of the charging roller 12. As a result, the separating member 200 is swingably supported with respect to the rotating shaft 12a. The separation holding portion 210 is arranged between the gear 36 provided on the photosensitive drum 11 and the rotating shaft 12a of the charging roller 12, and separates the photosensitive drum 11 and the charging roller 12 and secures a clearance. The separation holding portion 220 is arranged between the rotating shaft 12a of the charging roller 12 and the rotating shaft 13a of the cleaning roller 13, and separates the charging roller 12 and the cleaning roller 13 and secures a clearance.

Further, the two separation holding portions 210 and 220 and the swing support portion 230 are integrally formed. Therefore, when the separation member 200 is located in the first phase with respect to the swing direction, the separation holding portions 210 and 220 separate the photosensitive drum 11 and the charging roller 12, and the charging roller 12 and the cleaning roller 13, respectively. Hold in the state of being kept (separate holding state). On the other hand, when the separation member 200 swings from the first phase to the second phase with respect to the swing direction, as will be described later, the state in which the photosensitive drum 11 and the charging roller 12 are kept apart, and the charging roller 12 and the cleaning roller 13 are held. The separation holding state of is released at the same time (separation release state).

When the photosensitive drum 11 and the charging roller 12 are held apart from each other, the separation holding portion 210 is provided with the rotating shaft 12a (rotating shaft of the separating member 200) and the gear of the charging roller 12 by the pressing force (urging force) of the pressure spring 32. It is sandwiched between 36. Further, when the separation holding portion 220 is in the separation holding state between the charging roller 12 and the cleaning roller 13, the rotating shaft 13a of the cleaning roller 13 and the rotating shaft 12a of the charging roller 12 are subjected to the pressing force (urging force) of the pressure spring 34. It is sandwiched between them.

Further, as shown in FIG. 7A, the separation holding portion 210 of the separation member 200 has an engagement portion 211 that can be engaged with the gear 36. The engaging portion 211 is formed with gear teeth 211a as an engaging protrusion on the side surface of the separating holding portion 210 on the side facing the gear 36 in the separated holding state. Further, on the outer peripheral surface of the gear 36, an engaging recess 36a that can be engaged with the gear teeth 211a is formed over the entire circumference. That is, it is an engaging recess 36a between the gear teeth of the gear 36. The gear teeth 211a are formed at the same pitch as the pitch of the engaging recess 36a of the gear 36 (the pitch of the gear teeth of the gear 36). When the photosensitive drum 11 and the charging roller 12 are separated from each other, the gear teeth 211a of the engaging portion 211 are engaged with the engaging recess 36a of the gear 36. In the separating member 200, in a state where the engaging portion 211 is engaged with the gear 36 as a rotating member, the charging roller 12 resists the urging force of the pressure spring 32, and the photosensitive drum 11 and the charging roller 12 are held together. Hold in a separated position.

Further, the separation holding portion 220 of the separation member 200 has an engagement portion 221 as a cleaning member engaging portion that can be engaged with the rotating shaft 13a of the cleaning roller 13 as a part of the cleaning member. The engaging portion 221 is provided on the side surface of the separation holding portion 220 on the side facing the rotation shaft 13a in the separation holding state, and has a concave portion having substantially the same radius of curvature as the outer diameter of the outer peripheral surface of the cylindrical rotation shaft 13a. Is. The engaging portion 221 is engaged with the rotating shaft 13a in the separated holding state in which the charging roller 12 and the cleaning roller 13 are separated from each other. In other words, at this time, the separating member 200 makes the cleaning roller 13 resist the urging force of the pressure spring 34 in a state where the engaging portion 221 is engaged with the rotating shaft 13a as a part of the cleaning member. , The charging roller 12 and the cleaning roller 13 are held at a separated position.

The engaging portion 221 of the separation holding portion 220 is formed so as to engage with the rotating shaft 13a of the cleaning roller 13 in a state where the engaging portion 211 of the separation holding portion 210 is engaged with the gear 36. Therefore, in a state where the separating member 200 is located in the first phase with respect to the swing direction, the engaging portion 211 engages with the gear 36 and the engaging portion 221 engages with the rotating shaft 13a, respectively. Then, the charging roller 12 and the cleaning roller 13 are held in a separated state. Thereby, for example, when the drum cartridge 100 is transported, the elastic layer 12b of the charging roller 12 and the photosensitive drum 11 are separated from each other, and further, the charging roller 12 and the cleaning roller 13 are separated from each other to secure mutual clearance.

[Structure of separation release]
Next, using FIGS. 3, 4 and 7 (b), a separation release configuration is used in which the separation member 200 releases the separation holding state of the photosensitive drum 11, the charging roller 12, and the charging roller 12 and the cleaning roller 13. Will be explained. When the new drum cartridge 100 is attached to the apparatus main body 1a (FIG. 1) and the image forming apparatus 1 (FIG. 1) is started, the photosensitive drum 11 is provided with the apparatus main body 1a by the initial operation performed by the image forming apparatus 1. The driving force (rotational force) is input from the motor.

When the drum cartridge 100 is mounted on the apparatus main body 1a, as shown in FIG. 7A, the photosensitive drum 11 and the charging roller 12 and the charging roller 12 and the cleaning roller 13 are separated from each other. It is in a separated holding state. Then, when the rotation of the photosensitive drum 11 is started from this separated holding state, the gear 36 rotates with the rotation of the photosensitive drum 11 as shown in FIG. 7B. Then, the engaging portion 211 engaged with the gear 36 receives the rotational force of the gear 36, and the separating member 200 swings in the predetermined direction α (the direction of the arrow in FIG. 7B).

When the separating member 200 swings in the predetermined direction α in this way, the engaging portion 211 and the gear 36 are disengaged, and the separating holding portion 210 swings the rotating shaft 12a of the charging roller 12 (swinging of the separating member 200). It is released from the state of being sandwiched between the shaft) and the gear 36. As a result, the state in which the charging roller 12 is held at the separated position is automatically released. That is, the charging roller 12 comes into contact with the photosensitive drum 11. When the separating member 200 swings in the direction opposite to the predetermined direction α, the movement of the separating member 200 is restricted so that the engagement portion 211 and the gear 36 are not disengaged. There is.

Further, when the separating member 200 swings in the predetermined direction α, the engaging portion 221 and the rotating shaft 13a of the cleaning roller 13 are disengaged, and the separating holding portion 220 is disengaged from the rotating shaft 12a of the charging roller 12 and the cleaning roller. It is released from the state of being sandwiched between the rotating shafts 13a of 13. As a result, the state in which the cleaning roller 13 is held at the roller separated position is automatically released. That is, in the present embodiment, when the gear 36 is rotated by the initial operation of the image forming apparatus 1 after the drum cartridge 100 is mounted on the apparatus main body 1a, the separating member 200 swings in a predetermined direction α, and the charging roller 12 and the charging roller 12. The separated holding state of the cleaning roller 13 is automatically released at the same time.

[Regulation of movement of separating members]
Next, for example, a configuration capable of suppressing the inadvertent disengagement between the engaging portion 211 of the separating member 200 and the gear 36 even if a strong vibration is applied to the drum cartridge 100 during transportation of the drum cartridge 100. , 8 to 11 will be described. In the present embodiment, the regulating portion 300 as a regulating means suppresses the inadvertent disengagement between the engaging portion 211 of the separating member 200 and the gear 36. That is, the restricting portion 300 shakes the separating member 200 so that the separating member 200 does not disengage the engaging portion 211 and the gear 36 while the engaging portion 211 is engaged with the gear 36. It is restricted to move in the direction in which the distance between the center of motion and the center of rotation of the gear 36 increases (the direction in which the charged roller bearing 31 is guided along the slide guide portion 30c).

In the present embodiment, as shown in FIG. 8, the regulating portion 300 has an abutting portion 302 provided on the separating member 200 and an abutting portion 301 provided on the drum container 30. As shown in FIG. 9A, the abutting portion 302 is provided so as to project from the end surface of the separation holding portion 210 in the rotation axis direction of the photosensitive drum 11. Therefore, the abutting portion 302 is provided outside the photosensitive drum 11 in the direction of the rotation axis.

As shown in FIG. 9B, the abutting portion 301 is provided on the side wall 30a of the drum container 30 facing the end portion in the rotation axis direction of the photosensitive drum 11. Specifically, the portion of the side surface of the side wall 30a on the charging roller 12 side of the portion facing the rotation axis direction end of the photosensitive drum 11 is projected inward (charging roller 12 side) in the rotation axis direction. Therefore, the abutted portion 301 is formed. In such abutting portion 301, in a state where the engaging portion 211 is engaged with the gear 36, the separating member 200 is in a direction in which the distance between the swing center of the separating member 200 and the rotation center of the gear 36 increases. The abutting portion 302 is formed so as to abut when it moves.

That is, the abutted portion 301 has an abutting surface 301a on which the abutting portion 302 abuts. The abutting surface 301a is formed on the side where the separation member 200 is separated from the abutting portion 302 when the separation member 200 is in the separation holding state from the swing center of the separation member 200 and the rotation center of the gear 36. Has been done. Here, the separating member 200 is provided swingably with respect to the rotating shaft 12a of the charging roller 12, and the swing center of the separating member 200 and the rotation center of the charging roller 12 are substantially the same. Further, the charging roller 12 is urged toward the photosensitive drum 11 by the pressure spring 32, and the separation holding portion 210 of the separation member 200 is urged by the urging force of the pressure spring 32 to rotate the shaft of the charging roller 12. It is sandwiched between 12a and the gear 36.

Therefore, in the present embodiment, the separation member 200 is located on the side where the distance between the swing center of the separation member 200 (rotation center of the charging roller 12) and the rotation center of the gear 36 (rotation center of the photosensitive drum 11) is large. The direction is opposite to the urging direction of the pressure spring 32. Therefore, the abutting surface 301a is located in the direction opposite to the urging direction of the pressure spring 32 with respect to the abutting portion 302 when the separating member 200 is in the separated holding state. Therefore, when the abutting portion 302 abuts on the abutting surface 301a, the separating member 200 is restricted from moving in the direction away from the gear 36 against the urging force of the pressure spring 32.

Here, as shown in FIGS. 10A and 10B, the separation member 200 moves in a direction in which the distance between the swing center of the separation member 200 and the rotation center of the gear 36 increases while the separation member 200 is in the separation holding state. Let A be the distance between the abutting portion 302 and the abutted portion 301 in the non-butted state. The distance A is preferably larger than 0. That is, it is preferable that there is a gap between the abutting portion 302 and the abutted portion 301 in this state. The separation holding state is a state in which the separation member 200 holds the charging roller 12 at the separation position. Further, the state in which the separation member 200 does not move in the direction in which the distance between the swing center of the separation member 200 and the rotation center of the gear 36 increases is that the separation holding portion 210 of the separation member 200 is pressed against the gear 36. It is in a state of not being separated from the gear 36. In this state, the distance A is smaller than the length (engagement amount B) at which the gear teeth 211a and the engaging recess 36a overlap with respect to the protruding direction of the gear teeth 211a when viewed from the rotation direction of the gear 36. There is.

That is, as shown in FIGS. 10A and 10B, the relationship between the distance A between the abutting portion 302 and the abutting surface 301a and the engagement amount B between the gear 36 and the engaging portion 211 in the separated holding state is , The distance A is smaller in the slide direction of the charged roller bearing 31 (the direction in which the charged roller bearing 31 is guided along the slide guide portion 30c). That is, A <B. With this configuration, while the engaging portion 211 is engaged with the gear 36, the separating member 200 swings the separating member 200 so that the engaging portion 211 and the gear 36 are not disengaged from each other. It regulates movement in a direction in which the distance between the center and the rotation center of the gear 36 increases.

For example, the charging roller 12 may move away from the photosensitive drum 11 against the urging force of the pressure spring 32 due to vibration or dropping of the drum cartridge 100 during transportation. In this case, the separating member 200 supported on the rotation axis of the charging roller 12 also moves in the direction away from the photosensitive drum 11. However, since the distance A is smaller than the engagement amount B as described above, the abutting portion 302 abuts on the abutted portion 301 before the engagement between the engaging portion 211 and the gear 36 is disengaged, and the separating member The movement of the 200 is restricted, and it is possible to prevent the separation holding state from being released.

When the separation holding state is released, the gear 36 rotates together with the photosensitive drum 11 and the separation member 200 swings, so that the engagement between the engaging portion 211 and the gear 36 is released. At this time, since the separating member 200 is urged toward the photosensitive drum 11 by the pressure spring 32 together with the charging roller 12, the engagement between the engaging portion 211 and the gear 36 is disengaged, and the separating member 200 is moved to the photosensitive drum 11 side. Moving. In other words, while the separating member 200 swings, the abutting portion 302 provided on the separating member 200 moves in a direction away from the abutted portion 301. Therefore, the separation member 200 swings and the separation holding state is released without the abutting portion 302 interfering with the abutting portion 301.

Further, in the case of the present embodiment, the separation member 200 is automatically released from the position in the separation holding state when the abutting portion 302 abuts on the abutting portion 301, which is opposite to the rotation direction (predetermined direction α). It regulates rotation in the direction. Therefore, as shown in FIG. 11A, when the abutting portion 301 abuts against the abutting portion 302, the normal-direction drag force P exerted on the abutting portion 302 determines the separating member 200. It is formed so as to act in a direction of swinging in the direction opposite to the direction α.

In the present embodiment, as shown in FIG. 11B, with respect to the direction in which the abutting surface 301a of the abutted portion 301 is orthogonal to the urging direction S of the pressure spring 32 (FIG. 9A, etc.). It is inclined in the direction opposite to the predetermined direction α. In other words, the abutting surface 301a is composed of a surface inclined with respect to the sliding direction of the charging roller bearing 31.

This will be described in detail. When the abutting surface 301a comes into contact with the abutting portion 302, the drag force P in the normal direction exerted on the abutting portion 302 is opposite to the direction in which the separating member 200 rotates when the separating member 200 is automatically released (predetermined direction α). The inclined surface has a force component that rotates the separating member 200 in the direction. In other words, as shown in FIG. 11A, the drag force P in the normal direction generates a torque T that rotates the separating member 200 in a direction opposite to the predetermined direction α.

In the present embodiment, as shown in FIG. 11B, the normal direction N of the abutting surface 301a is the direction (that is, the urging direction) toward the rotation axis of the photosensitive drum 11 in the sliding direction of the charging roller bearing 31. It is oriented toward the cleaning blade 15a rather than S). As shown in FIG. 2, the cleaning blade 15a abuts in the counter direction with respect to the rotation direction of the photosensitive drum 11. Further, in order to clean the surface of the photosensitive drum 11 before charging the photosensitive drum 11, it is arranged on the upstream side of the charging roller 12 with respect to the rotation direction of the photosensitive drum 11. The separating member 200 swings in a predetermined direction α by rotating the photosensitive drum 11 in the rotation direction β. Therefore, the cleaning blade 15a is located in the direction opposite to the predetermined direction α with respect to the separating member 200. Therefore, in the present embodiment, it is assumed that the normal direction N of the abutting surface 301a faces the cleaning blade 15a side with respect to the urging direction S.

Here, if a large impact is applied to the drum cartridge 100 during transportation of the drum cartridge 100 or the like, the following problems may occur. That is, the relationship between the distance A between the abutting portion 302 and the abutting surface 301a and the engagement amount B between the gear 36 and the engaging portion 211 in the separated holding state due to deformation of the drum container 30 or the like is reversed from the above. There is a risk that it will end up. That is, there is a possibility that A> B.

However, by inclining the abutting surface 301a as described above, even if the gear 36 and the engaging portion 211 are temporarily separated from each other, for example, A> B, the separated holding state is inadvertently released. Can be suppressed. That is, when the separating member 200 moves due to an impact and the abutting portion 302 comes into contact with the abutting surface 301a, the direction in which the separating member 200 rotates at the time of automatic release to the abutting portion 302 is opposite to the direction (predetermined direction α). A drag force P in the normal direction that rotates in the direction is generated. Therefore, it is possible to suppress the rotation of the separation member 200 in the predetermined direction α, and even if A> B, it is possible to suppress the release of the separation holding state.

The feature of the present invention is further separated and maintained in addition to this configuration (a configuration in which the abutting portion 302 is provided on the separating member 200 and the abutting portion 302 of the separating member 200 abuts on the abutting portion 301 of the drum container 30). It is a configuration that suppresses the release of the state. Even if the separation member 200 is not provided with the abutting portion 302, it may be a modified example capable of suppressing the release of the separation holding state by having the configuration described later. In the present embodiment, as shown in FIG. 13, the separating member 200 has a supported portion 212 supported by the core metal of the charging roller and a supported portion extending from the supported portion along the core metal of the charging roller. It is configured to have a connecting portion 213 (stretched portion) for connecting the engaging portion and the engaging portion. If the length of the connecting portion is long, the connecting portion tends to bend starting from the supported portion. When an external force is applied to the photoconductor unit, the connecting portion may bend in the direction in which the engaging portion is separated from the gear. As a result, the engagement between the engaging portion and the gear may be disengaged. In order to prevent this, in the separation holding state, in the urging direction of the pressure spring 32 (first urging member), from the charging roller bearing on the opposite surface (opposite surface) of the gear 36 of the separation holding portion 210. The structure is such that the protruding protrusion 310 is abutted against. The protrusion 310 is a part of the charged roller bearing. In the present embodiment, the structure of the protrusion 310 is such that it protrudes from the charged roller bearing, but the shape is not limited to the protruding shape, and the protrusion 310 is separated even if the protrusion portion is not partially protruded from the charged roller bearing. Any configuration may be used as long as it abuts against the holding portion 210. With this configuration, it is possible to prevent the separation holding portion 210 from being separated from the gear 36 when the separation holding portion 210 is momentarily deformed when vibration or impact is applied to the drum cartridge 100. can. With this configuration, even if the rigidity of the separation holding portion 210 is low, it is possible to prevent the separation holding portion 210 from being separated from the gear 36 when vibration or impact is applied to the drum cartridge 100. ..

Here, the configuration of the protrusion 311 will be described with reference to FIGS. 11 and 12. FIG. 11 is a perspective view of the drum cartridge 100. Since the protrusion 311 constitutes a part of the charging roller bearing 31, it is provided outside the charging roller 12b in the direction of the rotation axis of the charging roller 12b. That is, the protrusion 311 is integrally molded with the charging roller bearing 31. FIG. 12 is a diagram showing the relationship between the protrusion 311 in the distance holding state and the distance holding portion 210. In the present embodiment, when the engaging portion 211 and the gear are engaged and the charging roller is separated from the photoconductor (separation state), the protrusion 311 is in contact with the separation holding portion 210. .. Due to the configuration in which the protrusion 311 presses the separation holding portion 210 by the urging force of the pressure spring 32, even if the engaging portion 211 receives a force in the direction away from the gear 36 when receiving a shock, the engagement is released. It can be suppressed. On the other hand, in the present embodiment, the portion of the protrusion 311 that comes into contact with the separation holding portion 210 has an arc shape. By forming the arc shape, the contact area between the protrusion 311 and the distance holding portion 210 can be reduced when the distance holding member 200 rotates, so that the protrusion 311 loads the rotation of the distance holding portion 210. Can be made smaller. Further, it is preferable that a part of the protrusion 311 overlaps with at least the engaging portion 211 in the direction of the rotation axis of the charging roller 12. With this configuration, it is possible to prevent the engaging portion 211 from being separated from the gear 36. In this embodiment, the distance A is shorter than the distance B.

In the present embodiment, when the engaging portion and the gear are engaged and the charging roller is separated from the photoconductor (separated state), the protrusion 311 is arranged in contact with the separation holding portion 210. Met. As other configurations, the following configurations are also possible. That is, the protrusions 311 are arranged with a distance C (shortest distance) from the distance holding portion 210 in the separated state. The distance C is shorter than the distance B (the amount of engagement between the engaging portion 211 and the gear 36) described above. With this configuration, when a shock is received, even when the engaging portion 211 receives a force in the direction away from the gear 36 and the engaging portion 211 moves in the direction away from the gear 36, the separation holding portion 210 Can be prevented from being disengaged by abutting the protrusion 311. Further, the distance C is shorter than the distance B. Even with such a configuration, the same effect as the above configuration can be obtained.

In the present embodiment, the protrusion 311 has an arc shape, but the shape is not limited to this, and other configurations may be used such that the width becomes smaller as the photosensitive drum 11 approaches.

In the present embodiment, the regulating portion is a plate-shaped protruding portion protruding from the side wall 30a of the drum container 30, but as shown in FIGS. 14 and 15, the side wall 30d of the drum container 30 is the regulating portion. It may be a configuration having the role of. That is, as shown in FIGS. 14 and 15, the end surface 31b of the charged roller bearing 31 has a role as the abutting portion 302, and the side wall 30d of the drum container 30 has a role as the abutting portion 301. It is a configuration having. Then, in a state where the engaging portion 211 is engaged with the gear 36 (separation holding state in FIG. 15), the distance between the separation member 200 and the swing center of the separation member 200 and the rotation center of the gear 36 increases (direction in which the distance between the separation member 200 and the rotation center of the gear 36 increases. When the charged roller bearing 31 moves in the direction of being guided along the slide guide portion 30c), the abutting portion 302 (end surface 31b of the charging roller bearing 31) becomes the abutted portion 301 (side wall 30d of the drum container 30). It is formed so as to hit against. Even with such a configuration, the engagement amount B (the length at which the engagement portion 211 is engaged with the gear 36) between the gear 36 of FIG. 14 and the engagement portion 211 is the separated holding state of FIG. It is desirable to have a relationship larger than the distance A (shortest distance) between the abutting portion 302 (end surface 31b of the charged roller bearing 31) and the abutting portion 301 (side wall 30d of the drum container 30).

As described above, even when vibration or impact is applied to the drum cartridge 100 and a force is applied to move the separation holding portion 210 in the direction away from the gear 36, the engaging portion 211 and the gear 36 are engaged with each other. Can be prevented from coming off. As a result, it is possible to reduce that the state of holding the distance between the photosensitive drum 11 and the charging roller 12 and the state of holding the distance between the charging roller 12 and the cleaning roller 13 unintentionally released.

1 Image forming device 1a Device body 11 Photosensitive drum (photoreceptor)
12 Charging roller 12a Rotating shaft 13 Cleaning roller (cleaning member)
13a Rotating shaft (part of cleaning member)
30 Drum container (frame)
30a, 30d Side wall 30b Connecting part 30c Slide guide part 31, 31A Charged roller bearing (roller holding part)
32 Pressurized spring (first urging member)
34 Pressurized spring (second urging member)
36 gear (rotating member)
36a Engagement recess 100 Drum cartridge (photoreceptor unit)
200, 200A Separation member 210 Separation holding part 211 Engagement part 211a Gear tooth (engagement protrusion)
220 Separation holding part 221 Engaging part (cleaning member engaging part)
300, 300A Restriction part 301, 301A Abutment part 301a, 301Aa Abutment surface 302, 302A Abutment part

Claims (3)

A photoconductor unit that can be attached to an image forming apparatus.
With a rotatable photoconductor,
A rotatable charging roller that comes into contact with the photoconductor and charges the photoconductor,
A charging roller bearing member that is attached to the rotating shaft of the charging roller and rotatably supports the charging roller.
An urging member provided on the charged roller bearing member and urging the charged roller toward the photoconductor, and a urging member.
A gear provided at the end of the photoconductor in the direction of the rotation axis,
A separating member provided on the rotating shaft of the charging roller, having an engaging portion that engages with the gear, and separating the charging roller and the photoconductor.
In a state where the engaging portion and the gear are engaged, the charging roller bearing member urged by the urging member is guided so that the charging roller is separated from the photoconductor, and the engagement is performed. A guide portion that guides the charged roller bearing member urged by the urging member so that the charging roller comes into contact with the photoconductor in a state where the portion and the gear are not engaged.
The frame that supports the photoconductor and
Equipped with
In a state where the engaging portion and the gear are engaged, the distance between the charged roller bearing member urged by the urging member and the frame is set to A, and the engaging portion engages with the gear. If the length is B,
A photoconductor unit characterized in that A <B is satisfied. A rotatable cleaning roller that comes into contact with the charging roller to clean the charging roller,
A cleaning roller bearing member that is attached to the rotating shaft of the cleaning roller and rotatably supports the cleaning roller.
A second urging member provided on the cleaning roller bearing member and urging the cleaning roller toward the charging roller.
In a state where the engaging portion and the gear are engaged, the cleaning roller bearing member guided by the second urging member is guided so that the cleaning roller is separated from the charging roller, and the cleaning roller bearing member is guided and A second guide for the cleaning roller bearing member urged by the second urging member so that the cleaning roller comes into contact with the charging roller when the engaging portion and the gear are not engaged. Information section and
The photoconductor unit according to claim 1, further comprising. Further provided with a driving force receiving portion for receiving a driving force for rotating the photoconductor,
In a state where the engaging portion and the gear are engaged, the engaging portion and the gear are engaged with each other as the driving force receiving portion receives the driving force and the gear rotates. The photoconductor unit according to claim 1 or 2, wherein the engagement portion and the gear are in a non-engaged state.

Images