JP7573997B2 - Cartridge Unit - Google Patents

Description

The present invention relates to a protective assembly for a cartridge that can be attached to an electrophotographic image forming device.

In image forming devices that form images on recording media using an electrophotographic image forming method, a process cartridge type device configuration is known. That is, to facilitate toner replenishment and maintenance, a process cartridge that detachably attaches to the main body of an image forming device has been put into practical use, with the photoconductor, charging means, developing means, cleaning means, etc., all assembled together in a frame to form a cartridge.

The photoconductor is rotatably supported in the cleaning frame of the process cartridge, with part of the surface of the photoconductor exposed through an opening in the frame. This means that there is a possibility that the user may come into contact with the surface of the photoconductor. If the user comes into contact with the surface of the photoconductor, oils from the user's hands may adhere to the surface of the photoconductor, causing image defects. To prevent the user from coming into contact with the surface of the photoconductor, the surface of the photoconductor may be covered with a cover member. The cover member serves to protect against dust and to prevent contact by the user.

In addition, when performing maintenance such as clearing a jam, a cartridge that was once installed in the main body may be removed and temporarily stored outside the main body. In that case, there is a possibility that the user will have to reattach the cover member. In this case, as in the above case, covering the surface of the photoreceptor with a cover member can prevent dust and user contact. In order to further reduce the risk of the user accidentally touching the surface of the photoreceptor, Patent Document 1 proposes a cover member and a sheet member attached to the cover member.

JP 2017-207731 A

The cover member described in Patent Document 1 can be removed once and then reattached to the cartridge.

The object of the present invention is to provide a technology that can improve the ease of attaching and detaching a cover member to a cartridge.

In order to achieve the above object, the cartridge unit of the present invention comprises:
A cartridge unit including a cartridge that is detachably attached to a main body of an image forming apparatus, and a cover member for protecting the cartridge, the cover member being required to be removed from the cartridge when the cartridge is attached to the main body of the image forming apparatus,
the cartridge includes a photosensitive drum and a frame body that rotatably supports the photosensitive drum, the frame body having an engaged portion and exposing a part of an outer circumferential surface of the photosensitive drum to the outside of the cartridge,
the cover member is integrally formed with an engaging portion that engages with the engaged portion and a cover portion that covers the part of the outer circumferential surface of the photosensitive drum,
The cover member is characterized in that at least the engagement portion and the cover portion have a light transmittance of 40% or more.

This invention improves the ease of attaching and detaching the cover member to the cartridge.

FIG. 1 is a perspective view of a cartridge protection assembly according to a first embodiment of the present invention; 1 is a cross-sectional view of an image forming apparatus according to a first embodiment of the present invention; 1 is a cross-sectional view of a cartridge according to a first embodiment of the present invention; FIG. 1 is an exploded perspective view of a cartridge according to a first embodiment of the present invention; FIG. 1 is an exploded perspective view of a cartridge according to a first embodiment of the present invention; 1 is a cross-sectional view of an image forming apparatus according to a first embodiment of the present invention; 1 is a cross-sectional view of an image forming apparatus according to a first embodiment of the present invention; FIG. 1 is a perspective view and a partial perspective view of an image forming apparatus according to a first embodiment of the present invention; FIG. 1 is a perspective view of a cartridge and a cover member according to a first embodiment of the present invention; FIG. 1 is a front view of a cartridge according to a first embodiment of the present invention; FIG. 1 is a side view of a cartridge according to a first embodiment of the present invention; FIG. 1 is a side view and a partial cross-sectional view of a cartridge according to a first embodiment of the present invention. Transmittance measurement method Relationship between color, thickness and light transmittance of cover material FIG. 11 is a front view of a cartridge according to a second embodiment of the present invention; FIG. 11 is a partial cross-sectional view of a cartridge according to a second embodiment of the present invention.

The following describes in detail the embodiments of the present invention with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the embodiments should be changed as appropriate depending on the configuration and various conditions of the device to which the invention is applied. In other words, it is not intended to limit the scope of the present invention to the embodiments described below.

Example 1
An electrophotographic image forming apparatus is an apparatus that forms an image on a recording medium using an electrophotographic image forming method. Examples of electrophotographic image forming apparatuses include electrophotographic copying machines, electrophotographic printers (LED printers, laser beam printers, etc.), facsimile machines, and word processors. A process cartridge is an apparatus in which an electrophotographic photosensitive member and a process means acting on the electrophotographic photosensitive member are integrated into a cartridge, and the cartridge is detachably mounted on the main body of an electrophotographic image forming apparatus. For example, an electrophotographic photosensitive member and at least one of the process means, that is, a developing means, a charging means, and a cleaning means, are integrated into a cartridge. In some cases, an electrophotographic photosensitive member and a developing means are integrated into a cartridge, and the former is a photosensitive member unit (or a cleaning unit), and the latter is a developing unit. In the following description, the direction of the rotation axis of the electrophotographic photosensitive drum is defined as the longitudinal direction. In addition, in the longitudinal direction, the side where the electrophotographic photosensitive drum receives a driving force from the main body of the image forming apparatus is defined as the driving side, and the opposite side is defined as the non-driving side.

The overall configuration and image forming process will be described with reference to Figures 2 and 3. Figure 2 is a cross-sectional view of the main body (electrophotographic image forming apparatus main body, image forming apparatus main body) A of an electrophotographic image forming apparatus according to one embodiment of the present invention, and a process cartridge (hereinafter, referred to as cartridge) B. Figure 3 is a cross-sectional view of cartridge B. Here, the main body A of the apparatus refers to the portion of the electrophotographic image forming apparatus excluding cartridge B.

<Overall Configuration of Electrophotographic Image Forming Apparatus>
The electrophotographic image forming apparatus (image forming apparatus) shown in Fig. 2 is a laser beam printer utilizing electrophotographic technology in which a cartridge B is detachably attached to an apparatus main body A. When the cartridge B is attached to the apparatus main body A, an exposure device 3 (laser scanner unit) is disposed for forming a latent image on an electrophotographic photosensitive drum 62 serving as an image carrier of the cartridge B. In addition, a sheet tray 4 is disposed below the cartridge B, which stores a recording medium (hereinafter referred to as a sheet material PA) on which an image is to be formed. The electrophotographic photosensitive drum 62 is a photosensitive member (electrophotographic photosensitive member) used for forming an electrophotographic image.

In addition, in the device main body A, a pickup roller 5a, a pair of feeding rollers 5b, a transfer guide 6, a transfer roller 7, a transport guide 8, a fixing device 9, a pair of discharge rollers 10, a discharge tray 11, etc. are arranged in this order along the transport direction D of the sheet material PA. The fixing device 9 is composed of a heating roller 9a and a pressure roller 9b.

<Image Formation Process>
Next, an outline of the image forming process will be described. Based on a print start signal, an electrophotographic photosensitive drum (hereinafter referred to as photosensitive drum 62, or simply photosensitive body 62, or drum 62) is rotated in the direction of arrow R at a predetermined peripheral speed (process speed).

The charging roller (charging member) 66 to which a bias voltage is applied comes into contact with the outer peripheral surface of the drum 62, uniformly charging the outer peripheral surface of the drum 62 (see FIG. 3). The exposure device 3 outputs laser light L corresponding to the image information. The laser light L passes through a laser opening 71h provided in the cleaning frame 71 of the cartridge B, and scans and exposes the outer peripheral surface of the drum 62. As a result, an electrostatic latent image corresponding to the image information is formed on the outer peripheral surface of the drum 62.

On the other hand, as shown in FIG. 3, in the developing unit 20 as a developing device, the toner T in the toner chamber 29 is stirred and transported by the rotation of the transport member (stirring member) 43, and is sent to the toner supply chamber 28.

The toner T is carried on the surface of the developing roller 32 by the magnetic force of the magnet roller 34 (fixed magnet). The developing roller 32 is a developer carrier that carries developer (toner T) on its surface in order to develop the latent image formed on the drum 62. The toner T is frictionally charged by the developing blade 42, while the layer thickness on the peripheral surface of the developing roller 32 as a developer carrier is regulated.

The toner T is supplied to the drum 62 in accordance with the electrostatic latent image, and develops the latent image. This makes the latent image visible as a toner image. The drum 62 is an image carrier that carries the latent image and the image formed with toner (toner image, developer image) on its surface. As shown in FIG. 2, the sheet material PA stored in the lower part of the device main body A is sent out from the sheet tray 4 by the pickup roller 5a and the pair of feeding rollers 5b in synchronization with the output timing of the laser light L. The sheet material PA is then transported via the transfer guide 6 to the transfer position between the drum 62 and the transfer roller 7. At this transfer position, the toner image is transferred sequentially from the drum 62 to the sheet material PA.

The sheet material PA onto which the toner image has been transferred is separated from the drum 62 and transported along the transport guide 8 to the fixing device 9. The sheet material PA then passes through the nip between the heating roller 9a and pressure roller 9b that make up the fixing device 9. In this nip, a pressure and heat fixing process is performed, and the toner image is fixed to the sheet material PA. After the toner image has been fixed, the sheet material PA is transported to the pair of discharge rollers 10 and discharged to the discharge tray 11.

As shown in FIG. 3, the drum 62 after transfer has residual toner removed from its outer peripheral surface by a cleaning member 77, and is used again in the image formation process. The toner removed from the drum 62 is stored in the waste toner chamber 71b of the cleaning unit 60. The cleaning unit 60 is a photosensitive drum unit that has the photosensitive drum 62.

In the above, the charging roller 66, the developing roller 32, the transfer roller 7, and the cleaning member 77 are process means that act on the drum 62.

<Overall Cartridge Configuration>
Next, the overall structure of the cartridge B will be described with reference to Figures 3, 4, and 5. Figure 3 is a cross-sectional view of the cartridge B, and Figures 4 and 5 are exploded perspective views for explaining the structure of the cartridge B. In this embodiment, the screws used to connect the various parts will be omitted from the description.

Cartridge B has a cleaning unit (photoconductor holding unit, drum holding unit, image carrier holding unit, first unit) 60 and a development unit (developer carrier holding unit, second unit) 20.

As shown in FIG. 3, the cleaning unit 60 as the first unit has a drum 62 as the first rotating body, a charging roller 66, a cleaning member 77, and a cleaning frame 71 as the first frame that supports them. On the driving side of the drum 62, a driving side drum flange 63 provided on the driving side is rotatably supported by a hole 73a of a drum bearing 73 (see FIG. 4). In a broad sense, the drum bearing 73 and the cleaning frame 71 can be collectively referred to as the cleaning frame.

On the non-driven side, as shown in FIG. 5, a hole (not shown) in the non-driven side drum flange is rotatably supported by a drum shaft 78 press-fitted into a hole 71c provided in the cleaning frame 71. Each drum flange is a bearing-supported part that is rotatably supported by a bearing part.

As shown in FIG. 3, in the cleaning unit 60, the charging roller 66 and the cleaning member 77 are each arranged in contact with the outer circumferential surface of the drum 62. The cleaning member 77 has a rubber blade 77a, which is a blade-shaped elastic member made of rubber as an elastic material, and a support member 77b that supports the rubber blade. The rubber blade 77a abuts against the drum 62 in a counter direction to the rotation direction of the drum 62. In other words, the rubber blade 77a abuts against the drum 62 so that its tip faces upstream in the rotation direction R of the drum 62.

Waste toner removed from the surface of the drum 62 by the cleaning member 77 is stored in a waste toner chamber 71b formed by the cleaning frame 71 and the cleaning member 77. As shown in FIG. 3, a scoop sheet 65 is provided on the edge of the cleaning frame 71 so as to abut against the drum 62 to prevent waste toner from leaking from the cleaning frame 71.

The charging roller 66 is rotatably attached to the cleaning unit 60 via charging roller bearings 67 at both ends in the longitudinal direction of the cleaning frame 71. The longitudinal direction of the cleaning frame 71 (the longitudinal direction of the cartridge B) is substantially parallel to the direction in which the rotation axis of the drum 62 extends (the axial direction). Therefore, hereinafter, when the term "longitudinal direction" or "axial direction" is used without any particular specification, the axial direction of the drum 62 is intended. The charging roller 66 is pressed against the drum 62 by the charging roller bearings 67 being pressed against the drum 62 by the biasing member 68. The charging roller 66 rotates following the rotation of the drum 62.

As shown in FIG. 3, the developing unit 20 as the second unit has a developing roller 32 as a second rotating body, a developing container 23 as a second frame body that supports the developing roller 32, a developing blade 42, etc. The developing roller 32 is rotatably attached to the developing container 23 by bearing members 26 (FIG. 4) and 27 (FIG. 5) provided at both ends.

A magnet roller 34 is provided inside the developing roller 32. In the developing unit 20, a developing blade 42 is arranged to regulate the toner layer on the developing roller 32. As shown in Figures 4 and 5, spacing members 38 are attached to both ends of the developing roller 32, and the developing roller 32 is held with a small gap between the developing roller 32 and the drum 62 by abutting the spacing members 38.

As shown in FIG. 3, a toner-preventing sheet 33 for preventing toner from leaking from the developing unit 20 is provided on the edge of the developing container 23 so as to abut against the developing roller 32. Furthermore, a transport member 43 is provided in the toner chamber 29 formed by the developing container 23 and the bottom member 22. The transport member 43 agitates the toner contained in the toner chamber 29 and transports the toner to the toner supply chamber 28.

As shown in Figures 4 and 5, the cartridge B is constructed by combining the cleaning unit 60 and the developing unit 20. When combining the developing unit 20 and the cleaning unit 60, first, the center of the first developing support boss 26a of the bearing member 26 is aligned with the first hanging hole 71i on the driving side of the cleaning frame 71, and the center of the second developing support boss 27a of the bearing member 27 is aligned with the second hanging hole 71j on the non-driving side. Specifically, by moving the developing unit 20 in the direction of arrow G, the first developing support boss 26a and the second developing support boss 27a are fitted into the first hanging hole 71i and the second hanging hole 71j. This allows the developing unit 20 to be movably connected to the cleaning unit 60. More specifically, the developing unit 20 is connected to the cleaning unit 60 so as to be rotatable (rotatable). That is, the developing roller 32 is connected to the drum 62 in a state in which it can be moved toward and away from the drum 62. After this, the drum bearing 73 is assembled into the cleaning unit 60 to form the cartridge B.

In this embodiment, the non-driven side biasing member 46L (FIG. 5) and the driven side biasing member 46R (FIG. 4) are formed of compression springs. The biasing force of these springs causes the driven side biasing member 46L and the non-driven side biasing member 46R to bias the developing unit 20 against the cleaning unit 60, thereby reliably pressing the developing roller 32 toward the drum 62. Furthermore, the developing container 23 is equipped with spacing members 38 attached to both ends of the developing roller 32. In other words, the drum 62 and the developing roller 32 come into contact with each other at a predetermined contact pressure via the spacing members 38, so that the developing roller 32 is held at a predetermined distance from the drum 62, and their relative positions are determined.

<Cartridge installation>
Next, the mounting of cartridge B will be specifically described with reference to Figures 6(a), 6(b), 7(a) and 7(b). Figure 6(a) is a cross-sectional view of the driving side guide portion of image forming apparatus A for explaining the mounting of cartridge B, and Figure 6(b) is a cross-sectional view of the non-driving side guide portion of image forming apparatus A for explaining the mounting of cartridge B. Figure 7(a) is a cross-sectional view of the driving side of image forming apparatus A for explaining the positioning of cartridge B. Figure 7(b) is a cross-sectional view of the non-driving side of image forming apparatus A for explaining the positioning of cartridge B.

The mounting of the cartridge B will now be described. As shown in Figures 6(a) and 6(b), the first driving side plate 15 has a guide rail upper portion 15g and a guide rail 15h as guides, and the non-driving side plate 16 has a guide rail upper portion 16d and a guide rail 16e. The drum bearing 73 provided on the driving side of the cartridge B has a rotation-stopped portion 73c. The mounting direction of the cartridge B is a direction (arrow C) that is substantially perpendicular to the axis of the drum 62 (Figure 3).

The cleaning frame 71 also has a positioned portion 71d as a first positioning portion and a rotation-stopped portion 71f as a second positioning portion on the non-driven side in the longitudinal direction. When the cartridge B is mounted through the cartridge insertion opening 17 of the main body A of the apparatus, the driven side of the cartridge B and the rotation-stopped portion 73c of the cartridge B are guided by the guide rail 15h of the main body A of the apparatus. On the non-driven side of the cartridge B, the positioned portion 71d and the rotation-stopped portion 71f of the cartridge B are guided by the guide rail 16d and guide rail 16e of the main body A of the apparatus. In this way, the cartridge B is mounted in the main body A of the apparatus.

Next, the state in which the opening/closing door 13 is closed will be described. As shown in Figures 6(a), 6(b), 7(a), and 7(b), the first driven side plate 15 has an upper positioning portion 15a, a lower positioning portion 15b, and a rotation stop portion 15c for positioning, and the non-driven side plate 16 has a positioning portion 16a and an upper rotation stop portion 16c. The drum bearing 73 has an upper positioned portion (first positioned portion, first protrusion, first overhang) 73d and a lower positioned portion (second positioned portion, second protrusion, second overhang) 73f.

The cartridge pressing members 1 and 2 are rotatably attached to both axial ends of the opening/closing door 13. The cartridge pressing springs 19 and 21 are attached to both longitudinal ends of a front plate provided in the image forming device A. The drum bearing 73 has a pressed portion 73e as a force receiving portion, and the cleaning frame 71 has a pressed portion 71o on the non-driven side (see FIG. 3). By closing the opening/closing door 13, the pressed portions 73e and 71o of the cartridge B are pressed by the cartridge pressing members 1 and 2 which are biased by the cartridge pressing springs 19 and 21 of the device main body A (see FIG. 7).

As a result, on the driving side, the positioned upper portion 73d, the positioned lower portion 73f, and the rotation stop portion 73c of cartridge B are fixed to the positioning upper portion 15a, the positioning lower portion 15b, and the rotation stop portion 15c of the device main body A, respectively. As a result, cartridge B and drum 62 are positioned on the driving side. Also, on the non-driving side, the positioned portion 71d and the rotation stop portion 71f of cartridge B are fixed to the positioning portion 16a and the rotation stop portion 16c of the device main body A, respectively. As a result, cartridge B and drum 62 are positioned on the non-driving side.

The above has been described as an example of a configuration for determining the position of cartridge B relative to the apparatus main body A, but is not intended to limit the means for positioning. A configuration may be used in which the positioning portions are fixed by directly acting on the positioned portion 73d and the rotation-stopped portion 73f on the drive side of cartridge B, and the positioned portion 71d and the rotation-stopped portion 71f on the non-drive side.

Next, the configuration in which cartridge B receives a driving force from the main assembly A of the apparatus will be described with reference to Figures 8(a), 8(b), 8(c), and 8(d). Figure 8(a) is a diagram showing the configuration of the drive section of the main assembly A of the apparatus, and Figure 8(b) is a diagram showing the configuration of the drive section of cartridge B. Figure 8(c) is a diagram showing the state before the drive sections of the main assembly A of the apparatus and cartridge B are engaged. Figure 8(d) is a diagram showing the state when the power of the main assembly A of the apparatus is turned on and the drive sections of the main assembly A of the apparatus and cartridge B are engaged.

As shown in Fig. 8(a), the main assembly A of the apparatus is provided with a drive transmission member 81 which receives a drive force from a drive source (not shown) of the main assembly A of the apparatus and transmits the drive force to the cartridge B. Also, as shown in Fig. 8(b), the cartridge B is provided with a drive receiving portion 63b on the drive side drum flange 63 in order to receive the drive force by engaging with the drive transmission member 81. Here, when the opening and closing door 13 is closed and the power supply of the main assembly A of the apparatus is turned on, the drive transmission member 81 moves in the direction of the arrow E in Fig. 8(c). Then, as shown in Fig. 8(d), the drive transmission portion 81b of the drive transmission member 81 engages with the drive receiving portion 63b of the drive side drum flange 63, and the drum 62 rotates via the drive side drum flange 63.

A gear shape 81g is provided on the outer periphery of the drive transmission member 81. A developing roller gear 90 is coupled to the end of the developing roller 32 of cartridge B. When the drive-receiving portion 63b of the driving side drum flange 63 shown in FIG. 8(d) is engaged, the gear shape 81g provided on the drive transmission member 81 and the developing roller gear 90 are also arranged to mesh with each other. That is, the drive transmission member 81 rotates the drum 62 via the driving side drum flange, and at the same time, the developing roller 32 also rotates via the developing roller gear 90.

<Cover member>
The characteristic cover member in this embodiment will be specifically described with reference to Figures 1 and 9. Figures 1 and 9 show the cartridge B and cover member 1001 in this embodiment. Figure 1 shows the state in which the cover member 1001 is assembled to the cartridge B, and Figure 9 shows the state before the cover member 1001 is assembled to the cartridge B. The configuration in which the cover member 1001 is assembled to the cartridge B in the state in which it is removed from the main assembly A of the apparatus as shown in Figure 1 is called a cartridge protection assembly for protecting the cartridge B.

As described above with regard to the overall cartridge configuration, the lower right in the figure shows the non-driven side having the bearing 27, and the upper left in the figure shows the driven side having the drum bearing 73. The photoconductor 62 is rotatably supported in the cleaning frame 71 of cartridge B, and part of the surface of the photoconductor 62 is exposed from the opening 71a of the frame 71 (see FIG. 3). Therefore, for example, there is a possibility that the user's hand may come into contact with the surface of the photoconductor 62. If the user's hand comes into contact with the surface of the photoconductor 62, hand oils and the like may adhere to the surface of the photoconductor 62, causing image defects.

In order to prevent the user's hand or other part from touching the surface of the photoconductor 62, the surface of the photoconductor 62 is covered with a cover member 1001 at the time of purchase, i.e., the product is shipped in the form of a protective assembly (see Figure 1). The cover member 1001 serves to prevent dust and to prevent the user from touching the photoconductor 62. It also serves to protect the photoconductor 62 from hitting it against any object.

In addition, when performing maintenance such as clearing a jam, cartridge B that has been installed in device main body A may be removed and temporarily stored outside device main body A. In that case, it is conceivable that the user will reattach cover member 1001 to cartridge B (see FIG. 9). In this case, as in the above case, covering the surface of photoconductor 62 with cover member 1001 can prevent dust and user contact.

The cover member 1001 has a shape along the longitudinal direction of the cartridge B (axial direction of the photosensitive member 62), and has recessed portions 1020 and 1030 at both ends, the recessed portions having a shape conforming to the outer diameter shape of the end of the cartridge B. The first recessed portion 1020 provided at one end of the cover member 1001 has a shape conforming to the shape of the non-driving side end of the cleaning frame 71, which is one end of the cartridge B. The first recessed portion 1020 includes a first wall portion 1021 facing the non-driving side end of the cleaning frame 71 in the longitudinal direction and a second wall portion 1022 facing the non-driving side end of the cleaning frame 71 in a direction perpendicular to the longitudinal direction, and is configured to cover a part of the outer shape of the non-driving side end. Similarly, the second recessed portion 1030 provided at the other end of the cover member 1001 has a shape conforming to the shape of the driving side end of the cleaning frame 71, which is the other end of the cartridge B. The second recessed portion 1030 includes a first wall portion 1031 that faces the driving side end of the cleaning frame 71 in the longitudinal direction, and a second wall portion 1032 that faces the driving side end in a direction perpendicular to the longitudinal direction, and is configured to cover a portion of the outer shape of the driving side end.

The positioning of the cover member 1001 on the cartridge B and the procedure for attaching the cover member 1001 to the cartridge B will be described below. The positioning configuration will be described in more detail with reference to Figs. 10, 11, and 12. Fig. 10 is a front view of the cartridge B according to the first embodiment of the present invention, Fig. 11 is a side view of the cartridge B according to the first embodiment of the present invention, and Fig. 12 is a side view and partial cross-sectional view of the cartridge B according to the first embodiment of the present invention. Fig. 10 is a front view of the cartridge B with the cover member 1001 attached, with the right side of the figure indicating the non-driven side and the left side of the figure indicating the driven side.

The installation of the cover member 1001 on the non-driven side to the cartridge B will be described using Figure 11. Figure 11 is a side view of the cartridge B as seen from the non-driven side, taken along the arrow F in Figure 10. Figure 11(a) shows the state before the cover member 1001 is installed, and Figure 11(b) shows the state after the cover member 1001 is installed.

The cartridge B has a cylindrically shaped positioned portion 71d provided on the frame 71, which protrudes in the longitudinal direction of the cartridge B. The cylindrical surface of the positioned portion 71d is provided with an engaged portion 71k and a locked portion 71m. The non-drive side positioning portion 1002 of the cover member 1001 has a cylindrical engaging portion 1002a, a locking arm 1002b, and a triangular claw-shaped locking portion 1002c at the tip of the locking arm 1002b.

To attach the cover member (non-driven side) 1002 to the cartridge B, as shown in FIG. 11(a), the cleaning unit 60 and the developing unit 20 are grasped and separated from each other to open a gap S. Then, the cover member 1001 is assembled in the direction of the arrow K so that the spacer portion 1002d is inserted into the gap S (the spacer portion 1002d is sandwiched between the cleaning unit 60 and the developing unit 20 in the gap S).

At the same time, the cover member (non-driven side) 1002 is assembled to the frame 71 so that the engaged portion 71k fits into the engaging portion 1002a. The cover member (non-driven side) 1002 is provided with guide portions 1002e and 1002f, allowing the user to easily assemble the cover member 1001 to the cartridge B.

During assembly, the locking arm 1002b bends in the direction of the arrow M due to elastic deformation, and the locking portion 1002c climbs over the locked portion 71m. The engaging portion 1002a abuts against the locked portion 71k, completing the assembly of the cover member (non-driving side) 1002. The climbing over locking portion 1002c abuts against the locked portion 71m, and functions as a snap fit portion that prevents the cover member 1001 from coming off in the direction opposite to the arrow K.

In a state in which the cover member (non-driven side) 1002 is assembled to the cartridge B, the engaging portion 1002a of the cover member (non-driven side) 1002 is provided inside the first recessed portion 1020 and is arranged to be hidden by the cover member (non-driven side) 1002. That is, when viewed in the longitudinal direction of the cartridge B, the engaging portion 1002a is in a position hidden by the first wall portion 1021, and a part of the tip portion of the cylindrical positioned portion 71d and the engaged portion 71k are also arranged to be hidden by the first wall portion 1021. The engaging portion 1002a is also in a position hidden by the second wall portion 1022 when viewed from the opposite side to the engaged portion 71k in a direction perpendicular to the longitudinal direction.

The locking portion 1002c also has a convex shape that protrudes in a direction perpendicular to the longitudinal direction of the cartridge B from the tip of the locking arm 1002b, which extends in a direction perpendicular to the longitudinal direction of the cartridge B, and when viewed in the perpendicular direction, it is hidden by the locking arm 1002b depending on the viewing angle. In other words, when viewed in the perpendicular direction, it has an angle such that the locked state between the locking portion 1002c and the locked portion 71m is hidden by the locking arm 1002b.

The cylindrical positioned portion 71d has an engaged portion 71k as part of its outer periphery, and a locked portion 71m is provided on the back side of the engaged portion 71k as part of the outer periphery. In other words, the cover member (non-driven side) 1002 is configured to have a wide range of angles at which the engaged state with the engaged portion 71k and the locked state with the locked portion 71m are hidden by the cover member (non-driven side) 1002 when viewed in a direction perpendicular to the longitudinal direction.

The spacing spacer portion 1002d is also angled so that the contact portion with the cleaning unit 60 is hidden by the first wall portion 1021 when viewed in the longitudinal direction, and is hidden by the second wall portion 1022 when viewed in a direction perpendicular to the longitudinal direction.

Figure 12 is a side view of cartridge B as seen from the drive side, taken along the line G in Figure 10. Figure 12(a) shows the state before the cover member 1001 is attached, and Figure 12(b) shows the state after the cover member 1001 is attached. Also shown for each are partial cross-sectional views H-H and J-J, taken along a horizontal plane that intersects the central axis of the photosensitive member 62.

The cartridge B has a drum bearing 73 as a frame body, a cylindrical (convex curved) upper positioned portion 73d and lower positioned portion 73f, and a concave locked portion 73g. The drive side positioning portion 1003 of the cover member 1001 has a cylindrical upper engaging portion 1003a and lower engaging portion 1003b, and a triangular claw-shaped locking portion 1003d at the tip of the locking arm 1003c (H-H cross section).

To attach the cover member (driving side) 1003 to the cartridge B, as shown in FIG. 12(a), the cleaning unit 60 and the developing unit 20 are grasped and separated from each other to open a gap S. Then, the cover member 1001 is assembled in the direction of the arrow L so that the spacer portion 1003e is inserted into the gap S (the spacer portion 1003e is sandwiched between the cleaning unit 60 and the developing unit 20 in the gap S).

At the same time, the cover member (driving side) 1002 is attached to the drum bearing 73 so that the upper positioned portion 73d and the lower positioned portion 73f fit into the upper engaging portion 1003a and the lower engaging portion 1003b.

During assembly, the locking arm 1003c bends in the direction of the arrow N due to elastic deformation, and the locking portion 1003d climbs over the locked portion 73g. The upper engaging portion 1003a and the upper engaging portion 1003b abut against the upper positioning portion 73d and the lower positioned portion 73f, respectively, completing the assembly of the cover member (driving side) 1003. The climbing over locking portion 1003d comes into contact with the locked portion 73g, thereby functioning as a snap fit portion that prevents the cover member 1001 from coming off in the direction opposite to the arrow L. The direction of elastic deformation of the locking portion 1003d is different from the direction of elastic deformation of the non-driving side locking portion 1002c.

In a state where the cover member (driving side) 1003 is assembled to the cartridge B, the engagement portions 1003a and 1003b of the cover member (driving side) 1003 are engaged with the first concave portion 1030.
and is disposed so as to be hidden by the cover member (driving side) 1003. That is, the engaging portions 1003a, 1003b are located in a position hidden by the first wall portion 1031 when viewed in the longitudinal direction of the cartridge B, and the positioned portions 73d, 73f are also disposed so as to be hidden by the first wall portion 1031. The engaging portions 1003a, 1003b are also located in a position hidden by the second wall portion 1032 when viewed from the opposite side to the positioned portions 73d, 73f in a direction perpendicular to the longitudinal direction.

The locking portion 1003d also has a convex shape that protrudes in the longitudinal direction from the tip of the locking arm 1003c that extends in a direction perpendicular to the longitudinal direction of the cartridge B, and is arranged so that it is hidden by the locking arm 1003c when viewed in the longitudinal direction. The locking portion 1003d is also hidden by other components of the cover member (driving side) 1003 depending on the viewing angle, even in the direction perpendicular to the longitudinal direction. In other words, the locking portion 1003d is arranged at an angle such that the locking state with the locked portion 73g, which has a concave shape recessed in the longitudinal direction, is hidden by the locking arm 1002b and other components of the cover member (driving side) 1003.

The spacing spacer portion 1003e is also angled so that the contact portion with the cleaning unit 60 is hidden by the first wall portion 1031 when viewed in the longitudinal direction, and is hidden by the second wall portion 1032 when viewed in a direction perpendicular to the longitudinal direction.

In this embodiment, the non-driven side uses the cylindrically-shaped protruding positioning portion 71d to form a snap-fit portion in the cross-sectional direction. Since the driven side does not have a protruding shape, a concavely-shaped engaging portion 73g is provided to form a snap-fit portion that elastically deforms in the longitudinal direction. As described above, in relation to other functional shapes, it is possible to adopt a snap-fit configuration in which the non-driven side and the driven side, i.e., one side and the other side in the longitudinal direction, undergo elastic deformation in different directions. Note that, as described above, the position at which the above-mentioned positioning portion is provided is not limited to both ends in the longitudinal direction along the rotation axis direction of the photosensitive body 62 (outside the longitudinal direction of the opening). For example, instead of providing them at both ends, a positioning configuration in which multiple positions are provided along the sides of the long opening edge extending in the longitudinal direction may be used. Alternatively, additional positions may be provided at locations other than both ends.

In addition, a spacer portion 1002d is inserted into the gap S on the non-driven side, and a spacer portion 1003e is inserted into the gap S on the driven side, and is sandwiched between the cleaning unit 60 and the developing unit 20. This creates and maintains a gap between the photoconductor 62 held in the cleaning unit 60 and the developing roller 32 held in the developing unit 20, and prevents the photoconductor 62 and the developing roller 32 from coming into contact with each other due to impact during logistics.

In this embodiment, the cover member 1001 is made of a transparent or semi-transparent material. As a result, as shown in FIG. 9, when assembling the cover member 1001 to the cartridge B, the cover member 1001 can be assembled while visually checking the photosensitive element 62, which the user is not desired to touch. As a result, the risk of the user accidentally touching the surface of the photosensitive element 62 can be reduced. Note that, although the entire cover member 1001 is made of a transparent or semi-transparent material in this embodiment, it may be configured to have transparent or semi-transparent portions only in necessary locations.

In addition, the area around the positioning portion for engaging the cover member 1001 with the cartridge B is made transparent or translucent. This improves the visibility of the shape for engaging the cover member 1001 with the cartridge B, and further reduces the risk that the user will accidentally touch the surface of the photosensitive element 62 while assembling the cover member 1001 with the cartridge B.

In particular, the periphery including the non-driving side positioning portion 1002 and the driving side positioning portion 1003 for engaging the cover member 1001 with the cartridge B is configured to be transparent or semi-transparent. This is because, if the cover member 1001 is somewhat soft, it may be easier to remove the cover member 1001 from the ends by having positioning portions at both longitudinal ends. This allows the user to recognize the engaging portion of the cover member 1001 with the cartridge B, improving the visibility of the shape for engagement and further reducing the risk that the user will accidentally touch the surface of the photosensitive member 62.

<Light transmittance>
13 is a diagram showing a system for measuring the light transmittance. The light transmittance of each portion of the cover member 1001 was measured as follows.

As shown in FIG. 13, a 6 mm diameter window 1104h, which is the light source entrance part, was placed above the box structure to prevent light from leaking from the inside, and the measurement part 1101a of the illuminometer 1101 ("HIOKI 3423 LUX HiTESTER" manufactured by Hioki E.E. Corporation) was placed below the light source entrance part. In addition, a sample fixing part 1102 was installed at the midpoint between the light source entrance part and the measurement part.

The sample fixing section 1102 is composed of a fixing plate 1103 on which the sample 1001a is placed, and a cover plate 1104 which covers the sample 1001a and also serves as the light source entrance section described above. The fixing plate 1103 has a recess 1103a which serves as a blank for placing the sample 1001a, facing the center of the measurement section 1101a. Both the fixing plate 1103 and the cover plate 1104 have windows 1103h and 1104h with a diameter of 6 mm, through which light from the light source passes, which are each placed facing the center of the measurement section 1101a. Using such an evaluation device, the translucency of the sample 1101a was evaluated.

In the detailed measurement method, the light from the light source 1105 is passed through the 6 mm diameter windows 1103h and 1104h of the fixing plate 1103 and the cover plate 1104 (without a sample), and the light from the light source is adjusted so that the reading of the illuminometer 1101 is 2000 lux. Then, the sample 1001a is placed on the blank 1103a of the fixing plate 1103 and covered with the cover plate 1104, so that the sample 1001a is interposed in the middle of the passage path of the light from the light source 1105. The value (U) of the illuminometer 1101 at that time was read. This operation was performed three times for each part, and the average value was taken as the light transmittance. The light transmittance T (%) was calculated by the following formula.
Light transmittance T (%) = U/2000×100

Table 1 in Figure 14 shows the relationship between the thickness and light transmittance of the cover member. The light transmittance of each part of a prior art cover member made of PS (polystyrene) and orange in color, and a cover member made of PP (polypropylene) and natural in color in this embodiment, was measured using the procedure described above. In addition to the light transmittance results, a judgment was also made as to whether the engagement part was visible.

As a result, it was found that if the light transmittance of the periphery of the cover member 1001, including the non-drive side positioning portion 1002 and the drive side positioning portion 1003 for engaging with the cartridge B, is 40% or more, the engaging portion is visible, making it easy to aim and assemble. Therefore, by configuring the periphery of the positioning portion for engaging the cover member 1001 with the cartridge B to be transparent or semi-transparent, the visibility of the shape for engaging the cover member 1001 with the cartridge B is improved. This further reduces the risk that the user will accidentally come into contact with the surface of the photosensitive member 62 while assembling the cover member 1001 to the cartridge B.

In this specification, "transparent" and "semi-transparent" do not require a clear boundary. For example, "transparent" can be used when the light transmittance is a relatively high value close to 100%, and "semi-transparent" can be used when the light transmittance is away from 100% but is at least 40%. That is, "transparent or semi-transparent" refers to a case where the cover member 1001 has a transparency (translucency) that allows the user to visually confirm the engagement portion and the position of the photosensitive member 62 through the cover member 1001 when attaching or detaching the cover member 1001 to the cartridge unit. In this embodiment, PP (polypropylene) is used as the material of the cover member as described above, but PS (polystyrene) may be used as long as it has a similar visibility.

Example 2
Fig. 15 is a front view of a cartridge B according to a second embodiment of the present invention, and Fig. 16 is a partial cross-sectional view of the cartridge B according to the second embodiment of the present invention, showing a partial portion of the cross section taken along line E-E of Fig. 15.

The cover member 1201 has a character-shaped portion 1201b on which characters indicating handling precautions are displayed on the outer surface 1201a covering the photoconductor 62. This character-shaped portion 1201b has a function of, for example, alerting the user not to touch the photoconductor 62 and informing the user of the upward direction of how to remove the cover member 1201. Since the character-shaped portion 1201b is arranged so as to cover the photoconductor 62, it can be emphasized as an alert to the target photoconductor 62. Possible methods for arranging the character-shaped portion 1201b include engraving in which characters are carved into a mold and the characters 1201b are drawn by molding. Other methods are also possible as long as characters and illustrations can be arranged.

It is also desirable to reduce the amount of material used to reduce the cost of the cover member 1201. To achieve this, as shown in FIG. 16, it is considered to reduce the thickness t of the cover member 1201. If the thickness is too thin, the resin may not circulate completely and may cause a short circuit, so a balance must be taken with moldability. Specifically, it is necessary to ensure that the resin flowing in from the gate (part 1201g of the cover member 1201 corresponding to the gate) in the molding die flows to every corner of the cavity of the molding die. To achieve this, it is possible to make the thickness t1 of the part of the cover member 1201 that corresponds to the central flow path of the molding die (central flow path part) 1201c thicker than the thickness t2 of the part of the cover member 1201 that corresponds to the other flow paths of the molding die (other flow path parts) 1201d. This allows sufficient fluidity to be maintained and the amount of resin used to be reduced.

In this case, a thickness difference (t2-t1) occurs between the adjacent central flow passage portion 1201c and the other flow passage portion 1201d, but by smoothly connecting them at the joint 1201e, the step can be made inconspicuous. In other words, the thickness change at the joint 1201e connecting the parts of the cover member 1201 with different thicknesses is configured to gradually change at least in the area that overlaps with the character shaped portion 1201b. As a result, the step at the joint 1201e is made inconspicuous against the outline of the character 1201b drawn on the surface of the transparent or translucent cover member 1201, and the visibility of the character shaped portion 1201b can be maintained. Furthermore, by coloring the engraving, the visibility of the character shaped portion 1201b can be further improved.

<Covering member for developing roller>
In this embodiment, the cover member for the photosensitive body has been described as a rotating body of the cartridge, but the same configuration can be applied to the cover member for the developing roller, and the same effect can be obtained. For example, the present invention is preferably applicable to a case where a developing unit having a developing roller is separated from a photosensitive body unit having a photosensitive body and made into a cartridge, and the developing cartridge is configured to be detachable from the main body of the device alone. That is, the visibility of the shape for engaging the cover member with the developing cartridge is improved, and the risk of the user accidentally touching the surface of the developing roller while assembling the cover member to the developing cartridge can be further reduced.

B... cartridge, 62... photosensitive drum, 71... cleaning frame, 71a... opening, 73... drum bearing, 1001... cover member

Claims (16)

A cartridge unit including a cartridge that is detachably attached to a main body of an image forming apparatus, and a cover member for protecting the cartridge, the cover member being required to be removed from the cartridge when the cartridge is attached to the main body of the image forming apparatus,
the cartridge includes a photosensitive drum and a frame body that rotatably supports the photosensitive drum, the frame body having an engaged portion and exposing a part of an outer circumferential surface of the photosensitive drum to the outside of the cartridge,
the cover member is integrally formed with an engaging portion that engages with the engaged portion and a cover portion that covers the part of the outer circumferential surface of the photosensitive drum,
A cartridge unit, wherein at least the engaging portion and the cover portion of the cover member have a light transmittance of 40% or more. the engaged portion is provided at an end of the frame body in a direction of a rotation axis of the photosensitive drum,
the cover member includes a first wall portion provided outwardly with respect to the end portion in the direction of the rotation axis, the first wall portion overlapping with the end portion when viewed in the direction of the rotation axis, and a second wall portion overlapping with the end portion when viewed in a direction perpendicular to the direction of the rotation axis,
the engagement portion is disposed inside the first wall portion in the direction of the rotation axis,
2. The cartridge unit according to claim 1, wherein the first wall portion and the second wall portion have a light transmittance of 40% or more. the engagement portion overlaps with the first wall portion when viewed in the direction of the rotation axis, and overlaps with the second wall portion when viewed in the perpendicular direction;
3. The cartridge unit according to claim 2. the frame has a positioning portion for determining a position of the cartridge with respect to the main body of the apparatus,
the positioned portion has a cylindrical portion extending in the direction of the rotation axis, includes the engaged portion on an outer circumferential surface of the cylindrical portion, and at least a part of a tip of the cylindrical portion and the engaged portion overlap with the first wall portion when viewed in the direction of the rotation axis.
4. The cartridge unit according to claim 3. The cover member has a locking arm extending in the perpendicular direction, and a locking portion provided at a tip of a free end side of the locking arm and protruding in the perpendicular direction,
the frame body has a locked portion provided on the outer circumferential surface of the cylindrical portion on a radially opposite side to the engaged portion when viewed in the direction of the rotation axis, the locked portion being locked to the locking portion,
the locking portion and the locked portion are provided at positions overlapping the locking arm when viewed in the perpendicular direction,
The light transmittance of the locking arm and the locking portion is 40% or more.
5. The cartridge unit according to claim 4. the cover member has a locking arm extending in the perpendicular direction, and a locking portion provided at a tip of a free end side of the locking arm and protruding in the direction of the rotation axis,
the frame body has a locked portion having a recessed portion recessed in the direction of the rotation axis, the locked portion being locked to the locking portion,
the locking portion and the locked portion are positioned to overlap with the locking arm when viewed in the direction of the rotation axis,
The light transmittance of the locking arm and the locking portion is 40% or more.
5. A cartridge unit according to claim 2, wherein the cartridge unit is a cartridge holder. If the frame body is a first frame body,
The cartridge comprises:
a first unit having the photosensitive drum and the first frame;
a second unit including a developing roller configured to supply toner to the photosensitive drum and a second frame that rotatably supports the developing roller;
Equipped with
the cover member has a spacer portion inserted between the first unit and the second unit,
the spacer portion has a contact portion that contacts the first unit,
the abutment portion is located at a position overlapping the first wall portion when viewed in the direction of the rotation axis, and overlapping the second wall portion when viewed in the perpendicular direction;
7. A cartridge unit according to claim 2, wherein the cartridge unit is a cartridge holder. The entire material of the cover member is polypropylene,
The material color of the cover member is a natural color.
8. A cartridge unit according to claim 1, wherein the cartridge unit is a cartridge holder. A cartridge unit according to any one of claims 1 to 8, characterized in that the overall light transmittance of the cover member is 40% or more. A cartridge unit including a cartridge that is detachably attached to a main body of an image forming apparatus, and a cover member for protecting the cartridge, the cover member being required to be removed from the cartridge when the cartridge is attached to the main body of the image forming apparatus,
the cartridge includes a photosensitive drum and a frame that rotatably supports the photosensitive drum, the frame having an engaged portion and exposing a part of an outer circumferential surface of the photosensitive drum to the outside of the cartridge,
the cover member has an engaging portion that engages with the engaged portion and covers the part of the outer circumferential surface of the photosensitive drum,
The entire material of the cover member is polypropylene,
The overall material color of the cover member is natural color.
A cartridge unit characterized by: the engaged portion is provided at an end of the frame body in a direction of a rotation axis of the photosensitive drum,
the cover member includes a first wall portion provided outwardly of the end portion in the direction of the rotation axis, the first wall portion overlapping the end portion when viewed in the direction of the rotation axis, and a second wall portion overlapping the end portion when viewed in a direction perpendicular to the direction of the rotation axis,
The cartridge unit according to claim 10, wherein the engaging portion is disposed inside the first wall portion in the direction of the rotation axis. the engagement portion overlaps with the first wall portion when viewed in the direction of the rotation axis, and overlaps with the second wall portion when viewed in the perpendicular direction;
12. A cartridge unit according to claim 11. the frame has a positioning portion for determining a position of the cartridge with respect to the main body of the apparatus,
the positioned portion has a cylindrical portion extending in the direction of the rotation axis, includes the engaged portion on an outer circumferential surface of the cylindrical portion, and at least a part of a tip of the cylindrical portion and the engaged portion overlap with the first wall portion when viewed in the direction of the rotation axis.
13. A cartridge unit according to claim 12. The cover member has a locking arm extending in the perpendicular direction, and a locking portion provided at a tip of a free end side of the locking arm and protruding in the perpendicular direction,
the frame body has a locked portion provided on the outer circumferential surface of the cylindrical portion on a radially opposite side to the engaged portion when viewed in the direction of the rotation axis, the locked portion being locked to the locking portion,
The locking portion and the locked portion are provided at positions overlapping the locking arm when viewed in the perpendicular direction.
14. A cartridge unit according to claim 13. the cover member has a locking arm extending in the perpendicular direction, and a locking portion provided at a tip of a free end side of the locking arm and protruding in the direction of the rotation axis,
the frame body has a locked portion having a recessed portion recessed in the direction of the rotation axis, the locked portion being locked to the locking portion,
The locking portion and the locked portion are positioned to overlap with the locking arm when viewed in the direction of the rotation axis.
14. A cartridge unit according to claim 11, wherein the cartridge unit is a cartridge holder. If the frame body is a first frame body,
The cartridge comprises:
a first unit having the photosensitive drum and the first frame;
a second unit including a developing roller configured to supply toner to the photosensitive drum and a second frame that rotatably supports the developing roller;
Equipped with
the cover member has a spacer portion inserted between the first unit and the second unit,
the spacer portion has a contact portion that contacts the first unit,
the abutment portion is located at a position overlapping the first wall portion when viewed in the direction of the rotation axis, and overlapping the second wall portion when viewed in the perpendicular direction;
16. A cartridge unit according to claim 11, wherein the cartridge unit is a cartridge holder.

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