JP2016206662A - Image carrier unit and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent start-up of an image forming device in a state that a separation member 3 enters between a photoreceptor drum 4 and a charging roller 5.SOLUTION: An image carrier unit comprises: a photoreceptor cartridge 1 having a photoreceptor drum 4 and a charging roller 5, and can be detachably attached to a device body 60A; a protection cover 2 capable of protecting the photoreceptor drum 4, and releasing protection of the photoreceptor drum 4 according to an attachment operation of the photoreceptor cartridge 1 to the device body 60A; and a separation member 3 capable of separating the photoreceptor drum 4 and the charging roller 5, and releasing separation of the photoreceptor drum 4 and the charging roller 5 according to the attachment operation of the photoreceptor cartridge 1 to the device body 60A. The protection cover 2 is moved to a take-out position where it can be taken out with respect to the photoreceptor cartridge 1 and moves the separation member 3 to a take-out position where the separation member can be taken out to the device body 60A, according to a protection release operation to the photoreceptor drum 4.SELECTED DRAWING: Figure 11

Description

  The present invention relates to an image carrier unit having an image carrier and a charged body, and an image forming apparatus that has an image carrier unit and forms an image on a sheet.

  2. Description of the Related Art Conventionally, image forming apparatuses such as copying machines, laser beam printers, and facsimile machines that use an electrophotographic process transfer and fix a toner image on a sheet to form a toner image on the sheet. Then, when transferring the toner image to the sheet, the image forming apparatus forms an electrostatic latent image by irradiating the photosensitive drum (image carrier) charged by the charging roller (charged body) with laser. The electrostatic latent image is developed with toner to form a toner image and then transferred to a sheet. In this case, the charging roller and the photosensitive drum are unitized as a photosensitive cartridge (image forming unit) and are detachably incorporated in the apparatus main body of the image forming apparatus. The charging roller needs to be in pressure contact with the photosensitive drum in order to charge the photosensitive drum.

  However, the photosensitive cartridge may not be used for a long period of time, for example, until it is shipped from the factory and unpacked by the user. In such a case, the outer peripheral surface of the charging roller pressed against the photosensitive drum is deformed, so that the charging roller cannot smoothly contact the photosensitive drum, and charging failure occurs in the photosensitive drum. In this state, the toner image transferred from the photosensitive drum to the sheet has streaks or the like, and the quality of the toner image is deteriorated. Further, when the charging roller is in contact with the photosensitive drum, frictional charging is generated at the contact portion between the charging roller and the photosensitive drum due to vibration during transportation, and a sliding memory in which electric charge is generated on the photosensitive drum 4 is generated. There are things to do. This rubbing memory appears as a streak in the toner image, and degrades the quality of the toner image.

  Therefore, conventionally, in order to cope with such a problem, a separation member (separation means) is detachable between the photosensitive drum and the charging roller until the photosensitive cartridge is mounted on the main body of the image forming apparatus. The photosensitive drum and the charging roller are separated from each other by mounting (Patent Document 1).

JP2013-214106A

  However, the user may forget to remove the separating member from between the photosensitive drum and the charging roller and install the photosensitive cartridge in the apparatus main body. When the image forming apparatus is activated in such a state, the photosensitive drum and the charging roller may be damaged by the separation member.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image carrier unit that prevents an image forming apparatus from being started in a state in which a separation unit is mounted between an image carrier and a charged body.

  An image carrier unit of the present invention has an image carrier that carries a toner image, and a charging member that contacts the image carrier and charges the image carrier, and is detachable from the apparatus main body. And a protection means for releasing the protection of the image carrier in accordance with the mounting operation of the image forming unit to the apparatus main body, the image carrier and the charging body. And a separating means for releasing the separation between the image carrier and the charging body in accordance with the mounting operation of the image forming unit to the apparatus main body, and the protection The means moves to a take-out position where it can be taken out from the image forming unit in accordance with the protection release operation for the image carrier, and the separation means is moved to a take-out position where it can be taken out from the apparatus main body. Thereby moving is characterized by.

  The image carrier unit of the present invention can prevent the image forming apparatus from being started in a state in which the separation unit is mounted between the image carrier and the charged body.

  In the image carrier unit of the present invention, the separation means of the image carrier protection unit is prevented from being used while entering the space between the image carrier and the charged body, and may be damaged by the separation means. Is prevented.

  The image forming apparatus according to the present invention forms an image on the sheet by the image forming unit having the image carrier unit that is prevented from being damaged by the separation unit of the image carrier unit. Can be formed.

2 is a schematic cross-sectional view of the image forming apparatus along a sheet conveying direction. FIG. FIG. 3 is a view in which an open / close door on the left side surface of the image forming apparatus is opened. FIG. 2 is an external perspective view of an image carrier unit, and is a diagram in which a photoconductor protection unit is mounted on a photoconductor cartridge as an image forming unit. FIG. 4 is a view of the photosensitive member cartridge of FIG. 3 as viewed from the rear lower side. FIG. 4 is a view of the photoconductor cartridge of FIG. 3 as viewed from below. FIG. 4 is a cross-sectional view taken along the line CC of FIG. 3 and is a diagram of a photoconductor cartridge with a photoconductor protection unit removed. It is an external appearance perspective view of a photoreceptor protection unit. It is DD sectional view taken on the line of FIG. FIG. 9 is a diagram in which the photoconductor protection unit of FIG. 8 is mounted on the photoconductor cartridge of FIG. 6. FIG. 10 is a diagram in which the photosensitive drum is covered with a protective cover from the state of FIG. 9. FIG. 3 is a view when the photosensitive cartridge is mounted on the apparatus main body of the image forming apparatus. FIG. 2 is a diagram in which a photosensitive cartridge is mounted on an apparatus main body of an image forming apparatus. It is a figure of the separation member of a shape different from the separation member shown in FIG. (A) is a figure of the separation member with a short length. (B) is a figure of the separation member with a long length. It is a figure of the separation member of a shape different from the separation member shown in FIG. (A) is a figure of the separation member with a short long hole. (B) is a figure of the separation member with a long long hole. It is a figure of the separation member of a shape different from the separation member shown in FIG.7, FIG.13, FIG.14.

  Hereinafter, an image forming apparatus equipped with a photosensitive cartridge (image forming unit) according to an embodiment of the present invention will be described with reference to FIG.

(Image forming device)
FIG. 1 is a schematic cross-sectional view of the image forming apparatus 60 along the sheet conveyance direction. The image forming apparatus 60 is configured to transfer and fix the toner image on the sheet P to form the toner image on the sheet. Examples of the image forming apparatus include a copying machine using an electrophotographic process, a laser beam printer, and a facsimile.

  The sheet P in the paper feed cassette 50 provided at the lower part of the apparatus main body 60 </ b> A of the image forming apparatus 60 is sent out by the pickup roller 59 and conveyed to the registration roller pair 53 by the paper feed roller pair 51.

  On the other hand, the photosensitive drum 4 is charged by the charging roller 5 while rotating in the arrow A direction, and a laser L corresponding to the image information is irradiated by the laser scanner 54 to form an electrostatic latent image. The electrostatic latent image is developed with toner by the developing sleeve 7 to become a toner image.

  The registration roller pair 53 straightly corrects the skew of the sheet, and then feeds the sheet to the transfer nip NP between the photosensitive drum 4 and the transfer roller 8 in accordance with the position of the toner image on the photosensitive drum 4. The transfer roller 8 transfers the toner image on the photosensitive drum 4 to the sheet, and sends the sheet to the fixing device 55 with the photosensitive drum 4. The fixing device 55 heats and presses the sheet to fix the toner image on the sheet, and sends the sheet to the paper discharge roller pair 56. The sheet discharge roller pair 56 discharges the sheet to the sheet discharge tray 57. A conveyance guide 52 for guiding the sheet P is provided from the pickup roller 59 to the paper discharge roller pair 56. In the above configuration, the photosensitive cartridge 1 having the photosensitive drum 4 and the charging roller 5, the developing sleeve 7, the transfer roller 8, and the like constitute an image forming portion (image forming means) 62.

(Image carrier unit)
FIG. 2 is a view in which the open / close door 58 on the left side surface of the image forming apparatus of FIG. 1 is opened. FIG. 3 is an external perspective view of the image carrier unit 100, in which the photosensitive member protection unit 70 is mounted on the photosensitive member cartridge 1 as an image forming unit. FIG. 4 is a view of the photoconductor cartridge 1 of FIG. 3 as viewed from the rear lower side. FIG. 5 is a view of the photosensitive cartridge 1 of FIG. 3 as viewed from below. FIG. 6 is a cross-sectional view taken along the line CC of FIG. 3 and is a view of the photosensitive member cartridge 1 with the photosensitive member protection unit 70 removed.

  In the image forming apparatus 60, a photosensitive drum 4 as an image carrier that carries a toner image, and a charging roller that is provided so as to be able to come into contact with and separate from the photosensitive drum 4 and charges the photosensitive drum 4 by contact. 5 and the like are unitized to form the photosensitive member cartridge 1. The photosensitive cartridge 1 is attached to and detached from the apparatus main body 60A of the image forming apparatus 60. The left side wall of the apparatus main body 60A in FIG. 1 is opened and closed by an opening / closing door 58 as shown in FIG. The photosensitive cartridge (image forming unit) 1 is guided by a guide groove described later with the open / close door 58 open, and can move in the directions of arrows B and J, and can be attached to and detached from the apparatus main body 60A. It has become.

  The image carrier unit 100 (FIG. 3) includes a photoreceptor cartridge (image forming unit) 1 and a photoreceptor protection unit 70. The photosensitive cartridge 1 includes a frame 80, a photosensitive drum 4, a charging roller 5, a cleaning blade 6, a pressure spring 9, and the like. Further, the photosensitive member cartridge 1 is provided with a removable photosensitive member protection unit 70 described later.

  The frame 80 is formed of a right side wall 81, a left side wall 82, a top plate 83 that connects the right side wall 81 and the left side wall 82, and the like. The right side wall 81 and the left side wall 82 are provided with handles 81 a and 82 a for holding the photosensitive cartridge 1. In FIG. 6, a residual toner collection box 84 is provided below the top plate 83. In FIG. 6, a cleaning blade 6 extending to the left is provided at the left inlet 84 a of the residual toner collection box 84. The cleaning blade 6 contacts the outer periphery of the photosensitive drum 4, removes toner remaining on the outer periphery of the photosensitive drum 4 rotating in the direction of arrow A from the photosensitive drum 4, and guides it to the residual toner collection box 84. It has become. The residual toner is toner remaining on the outer periphery of the photosensitive drum 4 after the toner image is transferred to the photosensitive drum 4.

  In FIG. 5, on the outside of the right side wall 81 and the left side wall 82, the first guide piece 13 and the second guide piece 14 are directed outward (the second guide piece 14 of the right side wall 81 is not shown). And project. The first guide piece 13 engages with a first guide groove 42 formed in a guide member 40 (FIGS. 2 and 11) provided in the apparatus main body 60A described later. The second guide piece 14 is adapted to engage with a second guide groove 43 formed in the guide member 40 (FIGS. 1 and 11).

  In FIG. 5, the photosensitive drum 4 and the charging roller 5 are rotatably provided on a right side wall 81 and a left side wall 82. The metal shafts 11 at both ends in the longitudinal direction of the charging roller 5 are held by charging roller bearings 10 provided on the right side wall 81 and the left side wall 82. The charging roller bearing 10 (FIG. 10 to be described later) is provided on the right side wall 81 and the left side wall 82 so as to move in a direction approaching and separating from the photosensitive drum 4. It is pressed in a direction approaching the body drum 4. As a result, the charging roller 5 is constantly pressed against the photosensitive drum 4.

  Here, the operation of the photosensitive cartridge 1 mounted on the apparatus main body 60A of the image forming apparatus 60 will be described based on FIG. 1, FIG. 5, and FIG.

  The charging roller 5 in contact with the photosensitive drum 4 by the charging roller pressurizing spring 9 is driven and rotated by the photosensitive drum 4, and the image forming high-pressure board is connected via the charging roller bearing 10 and the charging roller pressing spring 9. A voltage is applied from (not shown). The charging roller 5 to which a high voltage is applied gives a potential to the outer periphery of the photosensitive drum 4. The charged photosensitive drum 4 is irradiated with the laser L from the laser scanner 54, and the electric potential is lowered only in the exposed portion to form an electrostatic latent image. The electrostatic latent image is developed with toner supplied from a developing sleeve 7 disposed at a predetermined interval with respect to the photosensitive drum 4, and becomes a toner image.

  A sheet enters and is conveyed by being transferred to a transfer nip NP where the rotating photosensitive drum 4 and the transfer roller 8 are in contact with each other. A predetermined high voltage is applied to the transfer roller 8. For this reason, the toner image on the photosensitive drum 4 is transferred to the sheet. After the transfer, the residual toner remaining on the photosensitive drum 4 is scraped off by the cleaning blade 6. The photosensitive drum 4 from which the residual toner has been scraped is lowered to the initial state, and is charged by the charging roller 5 to form the next toner image. The charging roller 5 in the photosensitive cartridge 1 described above is driven and rotated by the photosensitive drum 4, but may be rotated by receiving the rotational force of a driving source such as a motor.

(Photoreceptor protection unit 70)
FIG. 7 is an external perspective view of the photoconductor protection unit 70. 8 is a cross-sectional view taken along the arrow D-D in FIG. 7. FIG. 9 is a diagram in which the photoconductor protection unit 70 of FIG. 8 is mounted on the photoconductor cartridge 1 of FIG. FIG. 10 is a diagram in which the photosensitive drum 4 is covered with the protective cover 2 from the state of FIG.

  The photoconductor protection unit 70 mainly includes a protective cover 2 and a separation member 3 and is detachably attached to the photoconductor cartridge 1.

  The protective cover (protective means, protective member) 2 is a long bowl-shaped member curved in a semicircular cross section. As shown in FIG. 10, the protective cover 2 is formed so as to cover a peripheral region where the transfer roller 8 and the developing sleeve 7 of the photosensitive drum 4 shown in FIG. 6 abut, and the photosensitive drum 4 is damaged. A member that protects the photosensitive drum 4 from being exposed to external light. That is, the protective cover 2 can protect the photosensitive drum 4. The area of the photosensitive drum 4 not covered by the protective cover 2 is covered and protected by a top plate 83, a residual toner collection box 84, a cleaning blade 6 and the like as shown in FIG.

  In FIG. 7, protective cover bearings 21 for detachably attaching the protective cover 2 to the photosensitive cartridge 1 are formed integrally with the protective cover 2 at the upper corners of both ends of the protective cover 2. The protective cover bearing portion 21 has a pair of elastic pieces 21a that extend in parallel to each other in the direction intersecting with the longitudinal direction of the protective cover 2 and inward. A slit 27 is formed between the pair of elastic pieces 21a. As shown in FIG. 8, a concave portion 21b is formed in the opposing portion of the tip of the pair of elastic pieces 21a. As shown in FIG. 9, the concave portion 21b receives the shaft 12 projecting in a direction approaching each other on the opposing surfaces of the right side wall 81 and the left side wall 82 of the photosensitive cartridge 1, and receives the shaft 12 of the pair of elastic pieces 21a. It is designed to be held by elasticity. In a state where the pair of elastic pieces 21a are attached to the shaft 12, the direction in which the elastic pieces 21a extend is a direction orthogonal to the direction in which the shaft 12 extends. The protective cover 2 can be attached to and detached from the photoreceptor cartridge 1 by attaching and detaching the pair of elastic pieces 21 a from the shaft 12. As a result, the photoconductor protection unit 70 can be attached to and detached from the photoconductor cartridge 1.

  In FIG. 7, projections 23 projecting in the longitudinal direction from both end portions are provided in the vicinity of the center of the arc portions at both end portions in the longitudinal direction of the protective cover 2. The protruding portion (contacted portion) 23 comes into contact with a stopper portion 41 (described later, FIGS. 11 and 12) formed on the apparatus main body 60A. At the position between the protective cover bearing portion 21 and the protruding portion 23 at both ends in the longitudinal direction of the protective cover 2, there is elasticity extending away from the protective cover 2 toward the protruding portion 23 from the protective cover bearing portion 21. A tongue piece 28 is provided. A protrusion 22 protrudes from the tip of the tongue piece 28 in the same direction as the protrusion 23. When the photosensitive drum 4 is protected by the protective cover 2, the protrusion 22 is engaged with an engaged hole 29 that is a through hole formed in the right side wall 81 and the left side wall 82 (FIG. 6). Yes. On the outer side of the central portion of the protective cover 2 in the longitudinal direction, a flat tab 24 protruding outward is projected. The knob 24 is a portion that is gripped by the user when the protective cover 2 is removed from the photoreceptor cartridge 1. In FIG. 7, a confirmation window 25 for confirming whether or not a later-described spacing member 3 has entered between the photosensitive drum 4 and the charging roller 5 is formed near both lower ends of the protective cover 2. Yes. The confirmation window 25 is a through hole formed in the protective cover 2.

  The separation member (separation means) 3 is provided at both ends of the rotation end 2a of the protective cover 2 in FIG. As shown in FIG. 10, the separating member 3 enters between the photosensitive drum 4 and the metal shaft 11 of the charging roller 5 against the pressure spring 9, and as shown in FIG. The body drum 4 and the charging roller 5 are separated from each other by about 1 mm. 1 mm is a reference value and is not a value that limits the present invention. In FIG. 8, the separation member 3 has a bearing portion 33 supported by a support shaft 71 formed near both corners of the rotation end 2 a of the protective cover 2. The bearing portion 33 is formed so as to surround the support shaft 71 with elasticity, and an opening 33 a is formed so that the separation member 3 can be attached to and detached from the support shaft 71. For this reason, the separation member 3 rotates about the support shaft 71 in the same directions E1 and E2 as the rotation directions E1 and E2 of the protective cover 2. Further, since the bearing portion 33 is loosely fitted to the support shaft 71, the contact force of the separating member 3 to the photosensitive drum 4 when the protective cover 2 and the separating member 3 rotate (protection release) is reduced. Thus, the surface of the photosensitive drum 4 is prevented from being scratched. Concave portions 31 and 32 are formed on the front and rear sides of the rotation direction E1 and E2 of the separating member 3, respectively. The concave portions 31 and 32 are portions that receive the photosensitive drum 4 and the metal shaft 11 when the separating member 3 enters between the photosensitive drum 4 and the metal shaft 11 of the charging roller 5. The concave portion 31 is a portion that receives the photosensitive drum 4, and is formed on an arc surface that matches the outer periphery of the photosensitive drum 4. The concave portion 32 is a portion that receives the metal shaft 11 of the charging roller, and is formed on an arc surface that matches the outer periphery of the metal shaft 11. The recesses 31 and 32 receive the photosensitive drum 4 and the metal shaft 11, and the separation member 3 comes out from between the photosensitive drum 4 and the metal shaft 11 due to vibration during conveyance or handling of the photosensitive cartridge 1. It is formed to prevent Moreover, the elastic force of the pressure spring 9 is applied to the metal drum 11 of the charging roller 5 on the photosensitive drum 4 side, so that the separation member 3 is difficult to come off.

  Next, an operation for mounting the photoconductor protection unit 70 to the photoconductor cartridge 1 will be described.

  First, the shaft 12 shown in FIG. 6 is inserted between the pair of elastic pieces 21a of the protective cover bearing portion 21 shown in FIGS. 7 and 8, and the concave portion 21b is engaged to support the protective cover bearing portion 21. Let As a result, the photoconductor protection unit 70 is supported by the shaft 12 between the right side wall 81 and the left side wall 82, and is rotatable in the directions of arrows E1 and E2 about the shaft 12 as shown in FIG. The photoconductor cartridge 1 is mounted. The shaft 12 protrudes from the right side wall 81 and the left side wall 82 so as to face each other, but the shaft 12 of the right side wall 81 is not shown.

  After that, as shown in FIG. 10, the protective cover 2 is rotated in the direction of the arrow E1 to approach the photosensitive drum 4, and the separating member 3 is also rotated in the direction of the arrow E1, so that the separating member 3 is moved to the photosensitive drum. 4 and the metal shaft 11 are made to enter against the elasticity of the pressure spring 9. The spacing member 3 is disposed between the photosensitive drum 4 and the metal shaft 11 by the elastic force of the pressure spring 9 with the concave portion 31 engaged with the photosensitive drum 4 and the concave portion 32 engaged with the metal shaft 11. It will be sandwiched. For this reason, the separation member 3 is prevented from coming out between the photosensitive drum 4 and the metal shaft 11. Further, when the protective cover 2 rotates in the direction of arrow E1, the protrusion 22 of the tongue piece 28 provided on the protective cover 2 engages with the engaged holes 29 of the right side wall 81 and the left side wall 82, respectively. For this reason, the protective cover 2 is prevented from rotating in the direction of the arrow E <b> 2 away from the photosensitive drum 4. In this way, the separation member 3 is prevented from coming off, and the protective cover 2 is prevented from rotating in the direction of the arrow E2, so that the photosensitive member is protected due to vibration during transportation or handling of the photosensitive cartridge 1. The unit 70 is prevented from leaving the photosensitive drum 4. Whether or not the separating member 3 is securely mounted between the photosensitive drum 4 and the metal shaft 11 can be confirmed through a confirmation window (opening) 25 by visual observation. The confirmation window 25 may be a notch.

  Next, the operation of mounting the photosensitive cartridge 1 mounted with the photosensitive body protection unit 70 on the apparatus main body 60A of the image forming apparatus 60 will be described. FIG. 11 is a view before the photosensitive cartridge 1 is mounted on the apparatus main body 60 </ b> A of the image forming apparatus 60. FIG. 12 is a diagram in which the photosensitive cartridge 1 is mounted on the apparatus main body 60 </ b> A of the image forming apparatus 60.

  In FIG. 5, on the outer side of the right side wall 81 and the left side wall 82 of the photosensitive member cartridge 1, the first guide piece 13 and the second guide piece 14 (the second guide piece of the right side wall 81) are directed outward. 14 is not provided). The guide member 40 (FIGS. 1 and 11) provided in the apparatus main body 60A of the image forming apparatus has a first guide groove 42 and a second guide piece 14 in FIG. It extends from the side to the right side.

  The transfer roller 8 is removed from the apparatus main body 60A before the photosensitive cartridge 1 is attached to the apparatus main body 60A. Then, the user grasps the handles 81 a and 82 a shown in FIG. 3, causes the first guide piece 13 to enter the first guide groove 42, and causes the second guide piece 14 to enter the second guide groove 43. . As shown in FIG. 5, two first guide pieces 13 and two second guide pieces 14 are provided (for convenience, the second guide piece 14 on the right side of FIG. 5 is not shown), and four are provided for convenience. For this reason, the photosensitive member cartridge 1 is pushed in the direction of the arrow B while being supported at four points with respect to the apparatus main body 60A.

  As shown in FIG. 11, in the middle of the photosensitive member cartridge 1 being pushed into the apparatus main body 60 </ b> A in the direction of the arrow B, the protrusion 23 provided on the photosensitive member protection unit 70 is formed on the guide member 40. It abuts against the protruding stopper portion 41.

  When the photosensitive cartridge 1 is further pushed into the apparatus main body 60A while the projection 23 remains in contact with the stopper 41, the protective cover 2 is centered on the shaft 12 as shown by the arrow E2 in FIG. Rotate in the direction. As the protective cover 2 rotates in the direction of arrow E2, the separating member 3 is pulled out from between the photosensitive drum 4 and the metal shaft 11. Here, the metal shaft 11 is constantly pressed toward the photosensitive drum 4 by the pressure spring 9. For this reason, when the separating member 3 is extracted, the charging roller 5 having the metal shaft 11 is pressed against the photosensitive drum 4. Further, when the protective cover 2 rotates in the direction of the arrow E2, the protrusion 22 comes out of the engaged hole 29. As the protective cover 2 rotates in the direction of the arrow E2, the separation member 3 is pulled out from between the photosensitive drum 4 and the metal shaft 11, and the protrusion 22 is pulled out from the engaged hole 29. The cartridge 1 becomes rotatable (rotatable).

  Thereafter, the user pushes the photoreceptor cartridge 1 to the position where the photoreceptor drum 4 approaches the developing sleeve 7 shown in FIG. 6 while grasping the handles 81a and 82a. From this state, when the user picks the knob 24 shown in FIGS. 2 to 4 and pulls it in the direction of the arrow J opposite to the arrow B, the protective cover bearing portion 21 is pulled out from the shaft 12 and the photosensitive member protection unit. 70 is removed from the photoreceptor cartridge 1. At this time, since the front ends of the pair of elastic pieces 21a of the protective cover bearing portion 21 are oriented in the push-in direction B, the photoconductor protection unit 70 can be easily detached from the photoconductor cartridge 1. It has become. Further, in a state before the photoconductor protection unit 70 is removed from the photoconductor cartridge 1, the tip portions of the pair of elastic pieces 21a face the direction intersecting with the pushing direction B. Therefore, when the protective cover 2 rotates, the pair of elastic pieces 21a are not easily detached from the shaft 12. Thereafter, the transfer roller 8 is mounted on the apparatus main body 60A and brought into pressure contact with the photosensitive drum 4, whereby the image forming operation by the image forming apparatus 60 becomes possible.

  When attaching / detaching the photosensitive cartridge 1 to / from the apparatus main body 60A, an adapter (not shown) attached / detached to / from the triangular connecting portion 4a of the photosensitive drum 4 (FIG. 3) as the opening / closing door 58 opens / closes. The rotation is transmitted to the photosensitive drum 4 by being attached to and detached from 4a.

  By the way, in FIG. 7, the separation member 3 is provided opposite to the charging roller 5 at both ends (lower corners of both ends) of the protective cover 2. For this reason, in the above description of the operation, when the separating member 3 comes out from between the metal shaft 11 of the charging roller 5 and the photosensitive drum 4, the charging roller 5 moves in parallel to the photosensitive drum 4 and approaches the charging roller. In many cases, almost all of 5 is in line contact with the photosensitive drum 4 at a time. In such a case, the photosensitive drum 4 may receive an impact depending on the structure of each part.

  In this case, instead of the separating members 3 provided at both ends of the protective cover 2 shown in FIG. 7, the separating members (103A, 103B), (203A, 203B), 303 shown in FIGS. Any one of the separation members can be provided to reduce the impact.

  Of the two spacing members 103A and 103B shown in FIG. 13, one spacing member (for example, FIG. 13A) is provided at one end of the protective cover 2 shown in FIG. For example, FIG. 13B is provided at the other end of the protective cover 2. The left and right spacing members 103A and 103B are also formed with bearings 133a and 133b that fit loosely on the support shaft 71, recesses 131a and 131b that receive the photosensitive drum 4, and recesses 132a and 132b that receive the metal shaft 11 of the charging roller 5. Has been. Furthermore, openings 133aa and 133ba are formed so that the separating members 103A and 103B can be attached to and detached from the support shaft 71. The two spacing members 103A and 103B are characterized in that the length L1 from the center OA to the tip of the recess 132a of one spacing member 103A is shorter than the length L2 from the center OB to the tip of the other spacing member 103B. (L1 <L2).

  As described above, when the left and right separation members 103A and 103B having different lengths come out from between the charging roller 5 and the photosensitive drum 4, the short length separation member 103A comes out first. For this reason, the charging roller 5 whose both ends are urged toward the photosensitive drum 4 by the pressure spring 9 is slightly inclined, and is moved from the end where the short separating member 103A is located to the photosensitive drum 4. Finally, the whole is brought into line contact with the photosensitive drum 4 after being pressed. As described above, the timing at which the left and right separation members 103A and 103B come out from between the charging roller 5 and the photosensitive drum 4 is shifted, thereby preventing the entire charging roller 5 from making line contact with the photosensitive drum 4 at once. can do. Therefore, the impact when the charging roller 5 is pressed against the photosensitive drum 4 can be reduced.

  Further, since the left and right separation members 103A and 103B have different lengths (L1 <L2), they do not enter between the charging roller 5 and the photosensitive drum 4 at the same time, and the long separation member 103B is the first. After entering, the separation member 103A having a short length enters later. For this reason, the left and right spacing members 103A and 103B are moved between the charging roller 5 and the photosensitive drum 4 with a smaller force than when the spacing members 3 having the same length shown in FIG. It can be easily entered.

  The left and right spacing members 203A and 203B shown in FIG. 14 are also configured such that the timing of exiting from between the charging roller 5 and the photosensitive drum 4 is deviated in the same manner as the left and right spacing members 103A and 103B shown in FIG. .

  As for the two spacing members 203A and 203B shown in FIG. 14, one spacing member (for example, FIG. 14A) is provided at one end of the protective cover 2 shown in FIG. FIG. 14B is provided at the other end of the protective cover 2. The left and right spacing members 203A and 203B are also formed with recesses 231a and 231b for receiving the photosensitive drum 4 and recesses 232a and 232b for receiving the metal shaft 11 of the charging roller 5.

  The two separation members 203A and 203B are formed with long holes 233a and 233b which are bearing portions that are loosely fitted to the support shaft 71, and in the direction of entering between the charging roller 5 and the photosensitive drum 4 simultaneously. It is provided so as to be movable with respect to the protective cover 2. The length L3 of the long hole 233a of the separation member 203A is shorter than the length L4 of the long hole of the separation member 203B (L3 <L4). For this reason, the two separation members 203A and 203B have different movement distances with respect to the support shaft 71 and the protective cover 2, and the separation member 203B has a longer movement distance than the separation member 203A. The distance L5 between the long hole 233a and the recess 231a and the distance L6 between the long hole 233b and the recess 231b are the same (L5 = L6). The distance L7 between the long hole 233a and the concave portion 232a and the distance L8 between the long hole 233b and the concave portion 232b are the same (L7 = L8).

  As described above, when the separation members 203A and 203B having the different lengths of the long holes 233a and 233b enter between the charging roller 5 and the photosensitive drum 4, the support shafts 71 corresponding to the left and right separation members 203A and 203B are provided. It enters in contact with the back sides 233aa and 233ba of the long holes. Since the distances (L5 = L6) and (L7 = L8) are satisfied, the left and right separation members 203A and 203B enter between the charging roller 5 and the photosensitive drum 4 simultaneously. However, when the left and right separation members 203A and 203B come out from between the charging roller 5 and the photosensitive drum 4, first, the support shaft 71 corresponding to the separation member 203A is placed on the near side 233ab of the long hole 233a having a short length. Abut. Thereafter, the support shaft 71 corresponding to the separation member 203B comes into contact with the front side 233bb of the long hole 233b having a long length. For this reason, the separation member 203 </ b> A having a short long hole comes out first from between the charging roller 5 and the photosensitive drum 4. Accordingly, the charging roller 5 whose both ends are biased toward the photosensitive drum 4 by the pressure spring 9 is slightly inclined, and is pressed against the photosensitive drum 4 from the end where the short separating member 203A is located. As a result, the entire body comes into line contact with the photosensitive drum 4.

  As described above, the timing at which the left and right separation members 203A and 203B come out from between the charging roller 5 and the photosensitive drum 4 is shifted, thereby preventing the entire charging roller 5 from making a line contact with the photosensitive drum 4 at a time. can do. Therefore, the impact when the charging roller 5 is pressed against the photosensitive drum 4 can be reduced.

  The separation member 303 shown in FIG. 15 is also provided instead of the separation member 3 provided at both ends of the protective cover 2 shown in FIG. The spacing member 303 is also formed with a bearing portion 333 a that is loosely fitted to the support shaft 71, a recess portion 331 that receives the photosensitive drum 4, and a recess portion 332 that receives the metal shaft 11 of the charging roller 5. Further, an opening 333aa that allows the separation member 303 to be attached to and detached from the support shaft 71 is also formed. The feature of the separation member 303 is that the tip portion entering between the photosensitive drum 4 and the charging roller 5 is formed of an elastic member (elastic body) 303c.

  Such a separation member 303 comes out while crushing the elastic member 303 c of the separation member 303 when it comes out of the charging roller 5 and the photosensitive drum 4. Therefore, the charging roller 5 whose both ends are urged toward the photosensitive drum 4 by the pressure spring 9 may reduce the impact when being pressed against the photosensitive drum 4 by the elastic member 303c of the separating member 3 being crushed. it can. Note that the distal ends of the separation members 103A and 103B shown in FIG. 13 and the separation members 203A and 203B shown in FIG. 14 may also be formed of an elastic member.

  As described above, when the photoconductor protection unit 70 is mounted on the photoconductor cartridge 1 and used, the following advantages are produced. Since the photosensitive drum 4 can be covered when the photosensitive cartridge 1 is stored as a part or in the course of being incorporated in the apparatus main body 60A, the photosensitive drum 4 is not damaged. Can be protected. Further, since the photosensitive drum 4 can be covered, the photosensitive drum 4 can be protected so that the photosensitive drum 4 is not unnecessarily exposed to external light. The photosensitive drum 4 and the charging roller 5 are separated from each other by the separation member 3 until the photosensitive cartridge 1 is partly assembled in the apparatus main body 60 </ b> A so that the pressure contact mark of the charging roller 5 does not adhere to the photosensitive drum 4. In addition, the charging roller 5 can be prevented from being deformed.

  Even if the photoconductor protection unit 70 is mounted on the photoconductor cartridge 1 and is mounted on the apparatus main body 60A, the protrusion 23 and the stopper portion 41 come into contact with each other, so that the photoconductor using the protective cover 2 is used. The protection of the drum 4 can be released. Accordingly, the protection of the photosensitive drum 4 by the photosensitive member protection unit 70 can be released along with the mounting operation of the photosensitive member cartridge 1. Further, the separation between the photosensitive drum 4 and the charging roller 5 by the separation member 3 is released along with the protection releasing operation of the photosensitive member protection unit 70. Therefore, the user can release the protection of the photosensitive drum 4 and release the separation between the photosensitive drum 4 and the charging roller 5 with the operation of mounting the photosensitive cartridge 1 to the apparatus main body 60A. With such a configuration, user convenience can be improved. Further, after the protection of the photosensitive drum 4 by the photosensitive member protection unit 70 is released, when the opening / closing door 58 is to be closed without removing the photosensitive member protection unit 70 from the photosensitive member cartridge 1, the opening / closing door is opened. 58 is prevented from being closed. This is because the end surface of the protective cover bearing portion 21 where the pair of elastic pieces 21 a are not provided is in contact with the open / close door 58. Therefore, it is possible to prevent the image forming apparatus 60 from operating while the photoconductor protection unit 70 is not removed. Further, the user knows that the photosensitive member protection unit 70 is still attached to the photosensitive member cartridge 1 due to the contact between the protruding portion 23 and the stopper portion 41. Therefore, at this time, the photosensitive member protection unit 70 may be removed from the photosensitive member cartridge 1 by the user.

  In the photosensitive cartridge 1 described above, the image forming apparatus 60 is prevented from being used in a state in which the separation member 3 of the photosensitive member protection unit 70 has entered between the photosensitive drum 4 and the charging roller 5. Therefore, the image forming apparatus 60 is used in a state in which the photosensitive drum 4 and the charging roller are separated from each other by the separation member 3, and the photosensitive drum 4 is prevented from being damaged.

  The image forming apparatus described above forms an image on the sheet by the image forming unit 62 having the photoconductor cartridge 1 that is prevented from being damaged by the separation member 3 of the photoconductor protection unit 70, so that the sheet has high quality. A toner image can be formed.

  1: Photosensitive cartridge (image forming unit) 2: Protective cover (protecting means, protective member), 3, 103A, 103B, 203A, 203B, 303: Separating member (separating means) 4: Photosensitive drum (image carrier) Body), 5: charging roller (charging body), 9: pressure spring, 10: charging roller bearing, 11: metal shaft of the charging roller, 12: photosensitive cartridge shaft, 13: first guide piece, 14: Second guide piece, 21: protective cover bearing portion, 23: protrusion (contacted portion), 24: knob, 25: confirmation window (opening), 26: protective portion, 27: slit portion, 31: separation Concave portion of member (separating means), 32: concave portion of separating member (separating means), 40: guide member, 41: stopper portion, 42: first guide groove, 43: second guide groove, 60: image forming apparatus 60A: Image forming apparatus main body 62: Image Forming part (image forming means), 70: photoconductor protection unit, 100: image carrier unit, 233a, 233b: long hole, 303c: elastic member (elastic body), P: sheet.

Claims (11)

An image carrier that carries a toner image, and a charging member that contacts the image carrier and charges the image carrier, and is detachable from the apparatus body;
Protecting means capable of protecting the image carrier, and releasing the protection of the image carrier as the image forming unit is attached to the apparatus main body.
The image carrier and the charged body can be separated from each other, and the separation between the image carrier and the charged body is released when the image forming unit is attached to the apparatus main body. Means, and
The protection means moves to a take-out position where the image forming unit can be taken out along with a protection release operation for the image carrier, and the take-out position where the separation means can be taken out from the apparatus main body. Move to
An image carrier unit characterized by that. The image forming unit is capable of forming an image on a sheet by being attached to the apparatus main body,
When the image forming unit is attached to the apparatus main body, the image forming unit further includes a contacted portion that contacts the apparatus main body,
The protection means releases the protection of the image carrier when the contacted portion comes into contact with the apparatus main body;
The image carrier unit according to claim 1, wherein: The protection means is rotatably mounted on the image forming unit,
The separation means releases the separation between the image carrier and the charged body in accordance with the rotation when the protection by the protection means is released.
The image carrier unit according to claim 1, wherein the image carrier unit is an image carrier unit. The separation means is provided rotatably with respect to the protection means,
Releasing the separation between the image carrier and the charged body as the protection means moves when the protection by the protection means is released;
The image carrier unit according to any one of claims 1 to 3, wherein the image carrier unit is provided. The separation means has a recess for receiving the image carrier and the charged body in a state of entering between the image carrier and the charged body.
The image carrier unit according to any one of claims 1 to 4, wherein the image carrier unit is provided. The separation means is provided at both ends of the protection means opposite to the charged body, and the timing of exiting between the image carrier and the charged body is different with the protection release operation.
The image carrier unit according to claim 2, wherein the image carrier unit is an image carrier unit. The separation means is provided at both ends of the protection means facing the charged body, and the lengths of the portions entering between the image carrier and the charged body are different.
The image carrier unit according to claim 2, wherein the image carrier unit is an image carrier unit. The separation means is provided at both ends of the protection means facing the charged body so as to be movable in a direction of entering the protection means in accordance with the protection release operation, and a moving distance with respect to the protection means is set. Different,
The image carrier unit according to claim 2, wherein the image carrier unit is an image carrier unit. In the separation means, a portion entering between the image carrier and the charged body is formed of an elastic body.
The image carrier unit according to any one of claims 1 to 8, wherein the image carrier unit is a unit. The protection means has an opening through which the separation means can be visually observed when entering between the image carrier and the charging body.
The image carrier unit according to any one of claims 1 to 9, wherein the image carrier unit is a unit. The image carrier unit according to any one of claims 1 to 10,
Image forming means for forming an image on a sheet based on a toner image carried on the image carrier released from protection by the protection means,
An image forming apparatus.

Images