Process unit and image forming apparatus equipped therewith

Abstract

The present invention provides a process unit and an image forming apparatus equipped therewith, which allow for the easy attachment of light diffusing members and toner receiving members with fewer steps. [Solution] A process unit P comprising a static elimination device 25 and a cleaning device 26 provided adjacent to the static elimination device 25 on the downstream side of the rotation direction R of the photoreceptor drum 23, wherein a light diffusing sheet 6 is provided between the light guide member 251 of the static elimination device 25 and the photoreceptor drum 23 to diffuse the light from the light guide member 251, and a toner receiving sheet 7 is provided in the cleaning device 26 on the upstream side of the rotation direction R of the photoreceptor drum 23 from the contact point α between the photoreceptor drum 23 and the cleaning blade 260 (cleaning member), and the light diffusing sheet 6 and the toner receiving sheet 7 are configured as a single continuous sheet member 9 arranged in this order along the rotation direction R of the photoreceptor drum 23.

Description

Technical Field

[0001] The present disclosure relates to a process unit and an image forming apparatus including the same.

Background Art

[0002] Conventionally, as a process unit of an image forming apparatus, there is known one including a charge removing device that removes residual charges on the outer peripheral surface of a photoreceptor drum by irradiating light on the outer peripheral surface (see, for example, Patent Document 1). Such a charge removing device generally has a light source and a light guiding member that guides light from the light source to the photoreceptor drum. Further, as described in Patent Document 1, as one means for suppressing an event (bright spot unevenness) in which light (charge removing light) guided to the photoreceptor drum by the light guiding member is concentrated on a local portion in the axial direction of the photoreceptor drum, it has been proposed to provide a light diffusing member that diffuses light from the light guiding member between the light guiding member and the photoreceptor drum.

[0003] Also conventionally, as a process unit, in order to suppress scattering of residual toner removed from the outer peripheral surface of a photoreceptor drum by a cleaning member, it is known to provide a toner receiving member on the upstream side in the rotation direction of the photoreceptor drum from the contact point between the photoreceptor drum and the cleaning member.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, if both the above-described conventional light diffusing member and the above-described conventional toner receiving member are provided in the process unit, there may occur a problem that the number of parts increases as compared with the case where only one of them is provided, and as a result, the mounting man-hours increase.

[0006] Furthermore, the size of the light-diffusing member only needs to be sufficient to cover localized areas where uneven bright spot formation may occur in the axial direction of the photoreceptor drum; therefore, they tend to be small and difficult to handle. For this reason, the conventional light-diffusing member alone presents a problem in that it is difficult to install.

[0007] This disclosure has been made in view of the above, and aims to provide a process unit and an image forming apparatus equipped therewith that can be easily attached with fewer steps to light diffusing members and toner receiving members. [Means for solving the problem]

[0008] To achieve the above objective, the process unit according to the present disclosure comprises a static elimination device that removes residual charge from the outer surface of a photoreceptor drum by irradiating the outer surface of the photoreceptor drum with light, and a cleaning device provided adjacent to the static elimination device downstream in the rotational direction of the photoreceptor drum, and for collecting residual toner from the outer surface of the photoreceptor drum, wherein the static elimination device comprises a light source and a light guide member that guides light from the light source to the photoreceptor drum, and a light diffusion sheet is provided between the light guide member and the photoreceptor drum to diffuse the light from the light guide member, and the cleaning The cleaning device has a cleaning member that removes the residual toner by contacting the outer surface of the photoreceptor drum, and a toner receiving sheet is provided upstream of the contact point between the photoreceptor drum and the cleaning member in the direction of rotation of the photoreceptor drum in the cleaning device to prevent the residual toner removed by the cleaning member from scattering outside the cleaning device, and the light diffusing sheet and the toner receiving sheet are configured as a single continuous sheet member arranged in this order along the direction of rotation of the photoreceptor drum.

[0009] According to the above configuration, both a light-diffusing sheet that diffuses light from the light-guide member and a toner-receiving sheet that prevents residual toner removed by the cleaning member from scattering outside the cleaning device are provided. Furthermore, since the light-diffusing sheet and the toner-receiving sheet are configured as a single continuous sheet member so that they are aligned in this order along the rotation direction of the photoreceptor drum, the light-diffusing sheet and the toner-receiving sheet can be arranged in this order along the rotation direction of the photoreceptor drum to correspond to the arrangement of the static eliminator and the cleaning device, and integrated. Therefore, the light-diffusing sheet and the toner-receiving sheet can be attached to the process unit as a sheet member at once. This makes it possible to easily attach the light-diffusing member (light-diffusing sheet) and the toner-receiving member (toner-receiving sheet) with fewer steps.

[0010] The above configuration is particularly advantageous when the size of the light-diffusing member is small and therefore difficult to handle on its own, considering that the size of the light-diffusing member only needs to be sufficient to cover localized areas where unevenness in bright spots may occur in the axial direction of the photoreceptor drum.

[0011] Furthermore, the image forming apparatus according to this disclosure includes the process unit described above. This allows the light diffusing member (light diffusing sheet) and the toner receiving member (toner receiving sheet) to be easily attached with fewer steps, similar to the above. [Effects of the Invention]

[0012] According to this disclosure, the light diffusion member and the toner receiving member can be easily attached with fewer steps. [Brief explanation of the drawing]

[0013] [Figure 1] Figure 1 is a schematic cross-sectional view showing an image forming apparatus in one embodiment of the present disclosure. [Figure 2] Figure 2 is a schematic cross-sectional view showing a portion of a process unit in one embodiment of the present disclosure. [Figure 3]Figure 3 is a schematic plan view showing an electrostatic elimination device in one embodiment of the present disclosure. [Figure 4] Figure 4 is a schematic partial side view, as seen from the photoreceptor drum side, showing an example of a sheet member. [Figure 5] Figure 5 is a schematic cross-sectional view showing the sheet member shown in Figure 4. [Figure 6] Figure 6 is a schematic cross-sectional view showing another example of a sheet member. [Modes for carrying out the invention]

[0014] The following describes the forms for implementing this disclosure, with reference to the drawings. (Embodiment 1) <Overall configuration of the image forming apparatus> Figure 1 is a schematic cross-sectional view showing an image forming apparatus 1 in one embodiment of the present disclosure. In this embodiment, the image forming apparatus 1 is described using an electrophotographic color multifunction printer with an intermediate transfer method capable of printing full-color images as an example. However, the image forming apparatus 1 is not limited to this, and various image forming apparatuses, including monochrome printers capable of printing single-color images (monochrome images), can be used.

[0015] First, the configuration of the image forming apparatus 1 will be described. As shown in Figure 1, the image forming apparatus 1 comprises an image reading unit 10 and an image forming apparatus body 11. In this embodiment, yellow (Y), magenta (M), cyan (C), and black (K) toners are used for printing by the image forming apparatus 1.

[0016] The image reading unit 10 reads images from the original document and is located above the main body 11 of the image forming apparatus. The image reading unit 10 includes a document reading device 12, a document placement table 13, and an automatic document processing device 14.

[0017] The original document reading device 12 irradiates light on the original document and reads an image from the original document based on the reflected light thereof. The original document reading device 12 incorporates, for example, a light source that irradiates light on the original document, a lens and an image sensor, and a mirror or the like that guides the reflected light of the original document to the lens. The reflected light of the original document that has entered the image sensor through the lens is photoelectrically converted by the image sensor, thereby generating image data corresponding to the image of the original document. Note that the image data may be generated by the image reading unit 10 or may be supplied from an external device.

[0018] The original document placement table 13 is a portion where the original document is placed by the user and is provided above the original document reading device 12. The original document placement table 13 is composed of transparent glass. The automatic original document processing device 14 automatically and continuously conveys the original document inserted by the user to the original document reading device 12 and is provided above the original document placement table 13. The image of the original document is read by the original document reading device 12 while being placed on the original document placement table 13 or while being conveyed to the original document reading device 12 by the automatic original document processing device 14.

[0019] The image forming apparatus main body 11 includes an image forming unit 20, an intermediate transfer unit 3, a secondary transfer unit 40, a fixing device 42, a sheet storage unit 43, a sheet roller group 5, and a sheet discharge unit 44. The image forming apparatus 1 is provided with a sheet conveyance path S through which the sheet is conveyed.

[0020] The image forming unit 20 forms toner images of respective colors on the outer peripheral surface 230 of the photosensitive drum 23 (on the photosensitive drum 23) based on the image data and has an exposure device 21 and (in this embodiment, four) process units P corresponding to respective colors. Each process unit P includes a developing device 22, a photosensitive drum 23, a charger 24, a discharging device 25, and a cleaning device 26 and is detachable from the image forming apparatus main body 11.

[0021] The exposure apparatus 21 forms electrostatic latent images corresponding to each color on the photoreceptor drum 23 by exposing the outer surface 230 of the photoreceptor drum 23 based on image data. The exposure apparatus 21 incorporates a light source that emits a laser beam, a polygon mirror that scans and reflects the laser beam, and optical elements (such as lenses and mirrors) for guiding the reflected laser light to the photoreceptor drum 23.

[0022] Each developing device 22 visualizes the electrostatic latent image formed on the corresponding photoreceptor drum 23 by using toners of each color (Y, M, C, K) supplied from the cartridge TC to form a toner image. The cartridge TC contains a developer containing toner.

[0023] The photoreceptor drum 23 is driven by a main motor (not shown) to rotate in a rotational direction R (not shown in Figure 1), and an electrostatic latent image can be formed on its outer surface 230. The charger 24 charges the outer surface 230 of the photoreceptor drum 23 to a predetermined potential (for example, about -600V). For the charger 24, for example, a contact type charger (for example, a roller type or brush type) or a charger type charger can be used. The static elimination device 25 and the cleaning device 26 will be described in detail later. Through a series of operations by the various components of the image forming unit 20 described above, toner images of each color are formed on the photoreceptor drum 23.

[0024] The intermediate transfer section 3 is used for so-called primary transfer, in which the toner images of each color formed on each photoreceptor drum 23 are sequentially transferred onto the intermediate transfer belt 30, and is located above the photoreceptor drum 23. The intermediate transfer section 3 includes the intermediate transfer belt 30, a drive roller 31, a driven roller 32, and a primary transfer roller 33. The primary transfer roller 33 is provided according to each color (four in this embodiment).

[0025] The intermediate transfer belt 30 is an endless belt that rotates in a predetermined direction and is suspended by a drive roller 31 and a driven roller 32. The toner images of each color, which are visualized on the photoreceptor drum 23, are sequentially transferred onto the intermediate transfer belt 30 and transported to the secondary transfer section 40 by the rotation of the intermediate transfer belt 30. The intermediate transfer belt 30 is made of, for example, a film with a thickness of about 100 μm to 150 μm. The drive roller 31 is a roller that is driven to rotate in a predetermined direction by a belt motor (not shown) and is provided on one end of the intermediate transfer section 3. The rotational drive of the drive roller 31 rotates the intermediate transfer belt 30. The driven roller 32 is a roller that is rotatably mounted along the intermediate transfer belt 30. The driven roller 32 rotates in accordance with the rotation of the intermediate transfer belt 30. The primary transfer rollers 33 are each provided on the opposite side of the image forming section 20, with the intermediate transfer belt 30 in between, and at positions corresponding to the photoreceptor drum 23. When a primary transfer bias is applied to the primary transfer roller 33, the toner image on the photoreceptor drum 23 is transferred to the intermediate transfer belt 30.

[0026] The secondary transfer section 40 is used for so-called secondary transfer, in which the toner images of each color transferred onto the intermediate transfer belt 30 are transferred to the sheet, and is provided on the sheet transport path S. The secondary transfer section 40 has a secondary transfer roller 41 provided at the transfer area where the sheet and the intermediate transfer belt 30 face each other. A secondary transfer bias is applied to the secondary transfer roller 41 to transfer the toner images of each color on the intermediate transfer belt 30 to the sheet.

[0027] The fixing device 42 fixes the toner image onto the sheet by heating and melting the toner image that has been secondarily transferred onto the sheet, thereby fixing the toner image onto the sheet, and is located downstream of the secondary transfer section 40 in the sheet transport path S.

[0028] The sheet storage section 43 houses the sheets used for image formation and is located at the bottom of the image forming apparatus body 11.

[0029] The sheet roller group 5 includes a pickup roller 5a, transport rollers 5b and 5c, and a registration roller 5d. The pickup roller 5a pulls out the top layer of sheets from the sheet storage section 43 and transports them to the sheet transport path S. The transport rollers 5b and 5c transport the sheets along the sheet transport path S. The registration roller 5d temporarily stops the sheets being transported from the sheet storage section 43 and aligns the leading edges of the sheets. Each of these sheet rollers 5 is rotated by a motor (not shown).

[0030] The sheet ejection unit 44 is located at the top of the image forming apparatus body 11 and is configured to allow printed sheets to be loaded and pulled face down.

[0031] The image forming apparatus 1 described above performs printing on the sheet as follows: First, a toner image based on image data generated by the image reading unit 10 or supplied from an external device is formed on the photoreceptor drum 23 by the image forming unit 20. Next, the toner image on the photoreceptor drum 23 is primary transferred to the intermediate transfer belt 30 of the intermediate transfer unit 3 by the primary transfer roller 33. During this time, the sheet is pulled out from the sheet storage unit 43 by the pickup roller 5a, transported to the register roller 5d by the transport roller 5b, and then transported to the secondary transfer unit 40 by the register roller 5d. Subsequently, the toner image primary transferred onto the intermediate transfer belt 30 is secondary transferred to the sheet by the secondary transfer unit 40. The toner image secondary transferred onto the sheet is fixed to the sheet by the fixing device 42. After that, the sheet is discharged onto the sheet discharge unit 44, and printing on the sheet is completed.

[0032] <Process Unit> The following describes the static elimination device 25 and cleaning device 26 of the process unit P, as well as the surrounding parts of these devices in the process unit P.

[0033] <Static eliminator> Figure 2 is a schematic cross-sectional view showing a part of the process unit P in one embodiment of the present disclosure. The thick arrows in Figure 2 conceptually indicate the direction of travel of the static elimination light. Note that the developing apparatus 22 is not shown in Figure 2. Note that hatching has been omitted in Figure 2 for ease of viewing, and the same applies to the following schematic cross-sectional views. Next, the configuration of the static elimination device 25 will be described. The static elimination device 25 removes residual charge (charge remaining on the photoreceptor drum 23 after primary transfer) from the outer surface 230 of the photoreceptor drum 23 by irradiating the outer surface 230 with light, and is a so-called light irradiation type static elimination device. The static elimination device 25 is provided upstream of the charger 24 in the rotation direction R of the photoreceptor drum 23. By removing the residual charge from the outer surface 230 of the photoreceptor drum 23 in advance by the static elimination device 25, the charger 24 can uniformly charge the outer surface 230.

[0034] Figure 3 is a schematic plan view showing a static elimination device 25 in one embodiment of the present disclosure. As shown in Figures 2 and 3, the static elimination device 25 includes a light source 250 and a light guide member 251. The light source 250 is composed of, for example, an LED lamp. As shown in Figure 3, the light source 250 is positioned outward from the light guide member 251 in the axial direction δ (hereinafter sometimes simply referred to as axial direction δ) toward the light guide member 251, so as to emit light (static elimination light) along the axial direction δ (hereinafter sometimes simply referred to as axial direction δ) of the photoreceptor drum 23.

[0035] The light guide member 251 guides the static-eliminating light emitted from the light source 250 to the photoreceptor drum 23 and is made of a light-transmitting material (for example, acrylic resin). As shown in Figure 3, the light guide member 251 is formed in an elongated shape that extends along the entire length of the photoreceptor drum 23 (the dimension of the outer peripheral surface 230 in the axial direction δ, and the same applies hereinafter), and has an incident surface 252 facing the light source 250, an exit surface 253 facing the photoreceptor drum 23, and a reflecting surface 254 inclined with respect to the incident surface 252 and the exit surface 253. The static-eliminating light emitted from the light source 250 is incident on the light guide member 251 at the incident surface 252, reflected toward the exit surface 253 at the reflecting surface 254, and emitted toward the photoreceptor drum 23 from the exit surface 253. In this way, the static-eliminating light is guided to the photoreceptor drum 23 by the light guide member 251. The light source 250 may be positioned radially outward of the photoreceptor drum 23 relative to the light guide member 251 so as to emit static elimination light along the direction normal to the outer peripheral surface 230 of the photoreceptor drum 23. In this case, the light source 250 may be composed of, for example, a plurality of light-emitting diodes (LEDs) mounted on a substrate so as to be spaced apart from each other in the axial direction δ, and the light guide member 251 may not have a reflective surface 254, but simply have an incident surface 252 and an exit surface 253 opposite to the incident surface 252.

[0036] To suppress the phenomenon (bright spot unevenness) in which the static-eliminating light guided to the photoreceptor drum 23 by the light guide member 251 concentrates in a localized area in the axial direction δ, a light diffusion sheet 6 is provided between the light guide member 251 and the photoreceptor drum 23 to diffuse the static-eliminating light from the light guide member 251. The light diffusion sheet 6 will be described in detail later.

[0037] <Cleaning device> Next, the configuration of the cleaning device 26 will be described. The cleaning device 26 collects residual toner (toner remaining on the photoreceptor drum 23 after primary transfer) from the outer peripheral surface 230 of the photoreceptor drum 23. As shown in Figure 2, the cleaning device 26 is installed adjacent to the static elimination device 25, downstream of the photoreceptor drum 23 in the rotation direction R. In other words, the static elimination device 25 and the cleaning device 26 are installed in this order in the rotation direction R of the photoreceptor drum 23.

[0038] As shown in Figure 2, the cleaning device 26 includes a cleaning blade 260 (cleaning member), a storage tank 261, and a transport member 262. The cleaning blade 260 removes residual toner by contacting the outer circumferential surface 230 of the photoreceptor drum 23, and is made of an elastic material (for example, urethane rubber). The cleaning blade 260 is formed in an elongated shape that extends along the entire length of the photoreceptor drum 23.

[0039] The storage tank 261 collects and stores residual toner removed by the cleaning blade 260, and constitutes part of the housing 8 described later. The transport member 262 transports the toner stored in the storage tank 261 to a waste toner box (not shown), and has a rotating shaft 263 extending in the axial direction δ, and a helical blade 264 provided on the outer circumferential surface of the rotating shaft 263.

[0040] In the cleaning device 26 described above, a toner receiving sheet 7 is provided upstream of the contact point α between the photoreceptor drum 23 and the cleaning blade 260 in the rotational direction R of the photoreceptor drum 23 (i.e., closer to the static eliminator 25) to prevent residual toner removed by the cleaning blade 260 from scattering outside the cleaning device 26. The toner receiving sheet 7 will be described in detail later.

[0041] The static elimination device 25 and cleaning device 26 described above are housed in the housing 8 of each process unit P, along with other components of the process unit P (developing device 22, photoreceptor drum 23, and charger 24, etc.). The housing 8 is made of a flame-retardant synthetic resin material.

[0042] As shown in Figure 2, the housing 8 in this embodiment is provided with an intermediate wall 80 that extends in the axial direction δ of the photoreceptor drum 23 between the static elimination device 25 and the cleaning device 26. The intermediate wall 80 divides the internal space of the housing 8 into a space where the static elimination device 25 is housed and a space where the cleaning device 26 is housed, and also constitutes a part of the housing tank 261 of the cleaning device 26.

[0043] The intermediate wall 80 has an end face portion 81 at the end closest to the photoreceptor drum 23 that extends in the axial direction δ of the photoreceptor drum 23 and faces the photoreceptor drum 23. In other words, the housing 8 is provided with an end face portion 81 that extends in the axial direction δ of the photoreceptor drum 23 and faces the photoreceptor drum 23. The length of the end face portion 81 (the dimension in the axial direction δ, and the same applies hereinafter) is set to be approximately the same as the total length of the photoreceptor drum 23.

[0044] <Sheet material> Figure 4 is a schematic partial side view of an example of the sheet member 9, as seen from the photoreceptor drum 23 side. Figure 5 is a schematic cross-sectional view of the sheet member 9 in Figure 4. In Figure 4, the sheet member 9 is shown with a thick line. In Figures 2 and 5, the thickness of the sheet member 9 is exaggerated for illustrative purposes.

[0045] As shown in Figures 2, 4, and 5, the light diffusion sheet 6 and the toner receiving sheet 7 are arranged in this order along the rotation direction R of the photoreceptor drum 23 and are configured as a single continuous sheet member 9. As shown in Figure 5, the sheet member 9 has a surface 90 facing the photoreceptor drum 23 and a back surface 91 facing the opposite direction from the surface 90. Hereinafter, the side facing the photoreceptor drum 23 may be referred to as the surface side, and the side opposite the surface side may be referred to as the back surface side. The sheet member 9 has a single continuous sheet substrate (reference numerals omitted) made of a synthetic resin material (for example, polyethylene terephthalate resin (PET), polycarbonate resin (PC), polyethylene resin (PE), polypropylene resin (PP), etc.).

[0046] As shown in Figures 2 and 5, the sheet member 9 in this embodiment is attached to the end face portion 81 of the housing 8 along the axial direction δ of the photoreceptor drum 23. Furthermore, as shown in Figures 4 and 5, the sheet member 9 in this embodiment is provided with a light diffusion portion 92 that functions as a light diffusion sheet 6, an adhesive portion 93 that is attached to the end face portion 81, and a toner receiving portion 94 that functions as a toner receiving sheet 7, arranged in this order along the rotation direction R of the photoreceptor drum 23. In other words, the adhesive portion 93 is provided between the light diffusion portion 92 and the toner receiving portion 94. In other words, the adhesive portion 93 is provided in the middle part of the sheet member 9 in the direction along the rotation direction R of the photoreceptor drum 23. The following describes each of these parts of the sheet member 9.

[0047] As shown in Figure 5, the light diffusing section 92 is positioned between the light guide member 251 and the photoreceptor drum 23, with a gap between them. The light diffusing section 92 contains light diffusing particles made of a light-transmitting material (e.g., acrylic resin) and a resin binder in its outer layer 920 on the back side. Specifically, the outer layer 920 of the light diffusing section 92 is formed by adhering the light diffusing particles to the outer surface of the sheet substrate with the resin binder. In Figure 5, the outer surface of the outer layer 920 is exaggerated to conceptually show its roughness. The static-dissipating light from the light guide member 251 is refracted and reflected repeatedly by the light diffusing particles as it passes through the light diffusing section 92, and is uniformly diffused in the axial direction δ. In this way, the light diffusing section 92 functions as a light diffusing sheet 6. This suppresses unevenness in the bright spots of the static-dissipating light guided to the photoreceptor drum 23 by the light guide member 251.

[0048] The length of the light diffusion section 92 is set to be sufficient to cover localized areas where bright spot unevenness may occur in the axial direction δ. As shown in Figure 4, the length of the light diffusion section 92 may be shorter than the total length of the photoreceptor drum 23. If there are multiple areas where bright spot unevenness may occur, the light diffusion section 92 is provided at multiple locations in the axial direction δ (intermittently in the axial direction δ) corresponding to each of those areas.

[0049] As shown in Figure 5, the attachment portion 93 is attached to the end face portion 81 of the housing 8 by an adhesive member T such as double-sided tape. The length of the attachment portion 93 is set to be approximately the same as the total length of the photoreceptor drum 23.

[0050] As conceptually shown in Figure 5, in this embodiment, the outer surface of the adhesive portion 93 attached to the end face portion 81 (i.e., the outer surface 930 on the back side) is smoother than the outer surface (reference numeral omitted) of the outer layer 920 of the light-diffusing portion 92. For example, unlike the light-diffusing portion 92, the adhesive portion 93 does not contain resin particles or the like in its outer layer (i.e., the outer layer (reference numeral omitted) on the back side). Therefore, compared to the case where the roughness of the outer surface 930 of the adhesive portion 93 attached to the end face portion 81 is the same as the roughness of the outer surface of the outer layer 920 of the light-diffusing portion 92, the outer surface 930 of the adhesive portion 93 can more accurately conform to the surface shape of the adhesive member T (or, if the thickness of the adhesive member T is extremely thin, the surface shape of the end face portion 81 to which it is attached). This makes it possible to more reliably adhere the adhesive portion 93 to the end face portion 81.

[0051] The toner receiving portion 94 extends from the attachment portion 93 downstream in the rotational direction R of the photoreceptor drum 23 to its tip, and has a contact portion 940 on the surface side of the tip portion that contacts the outer circumferential surface 230 of the photoreceptor drum 23. By contacting the outer circumferential surface 230 of the photoreceptor drum 23 at the contact portion 940, the toner receiving portion 94 blocks residual toner that would otherwise scatter between the photoreceptor drum 23 and the storage tank 261 of the cleaning device 26. In this way, the toner receiving portion 94 functions as a toner receiving sheet 7. This prevents residual toner removed by the cleaning blade 260 of the cleaning device 26 from scattering outside the cleaning device 26. In order to suppress the scattering of residual toner over the entire area of ​​the photoreceptor drum 23 in the axial direction δ, the length of the toner receiving sheet 7 is set to be approximately the same as the total length of the photoreceptor drum 23.

[0052] As conceptually shown in Figure 5, in this embodiment, the outer surface (not shown in Figure 5) of the contact portion 940 is smoother than the outer surface of the outer layer 920 of the light diffusion portion 92. For example, unlike the light diffusion portion 92, the contact portion 940 does not contain resin particles or the like in its outer layer (not shown in Figure 5). Therefore, compared to the case where the roughness of the outer surface of the contact portion 940 is the same as the roughness of the outer surface of the outer layer 920 of the light diffusion portion 92, gaps between the photoreceptor drum 23 and the toner receiving portion 94 caused by the surface shape are less likely to occur. This makes it possible to more reliably suppress residual toner removed by the cleaning blade 260 (not shown in Figure 5) from scattering outside the cleaning device 26 from between the photoreceptor drum 23 and the toner receiving portion 94.

[0053] The process unit P configured as described above is provided with both a light-diffusing sheet 6 that diffuses light from the light guide member 251 and a toner-receiving sheet 7 that suppresses residual toner removed by the cleaning blade 260 from scattering outside the cleaning device 26. The light-diffusing sheet 6 and the toner-receiving sheet 7 are configured as a single continuous sheet member 9 so that they are aligned in this order along the rotation direction R of the photoreceptor drum 23. As a result, the light-diffusing sheet 6 and the toner-receiving sheet 7 can be arranged in this order along the rotation direction R of the photoreceptor drum 23 to correspond to the arrangement of the static eliminator 25 and the cleaning device 26, and integrated. Therefore, the light-diffusing sheet 6 and the toner-receiving sheet 7 can be attached to the process unit P as a sheet member 9 at once. This makes it possible to easily attach the light-diffusing member (light-diffusing sheet 6) and the toner-receiving member (toner-receiving sheet 7) with fewer steps.

[0054] The above configuration is particularly advantageous when the size of the light diffusion sheet 6 is small and therefore difficult to handle on its own, considering that the size of the light diffusion sheet 6 only needs to be sufficient to cover localized areas where bright spot unevenness may occur in the axial direction δ of the photoreceptor drum 23.

[0055] Furthermore, as described above, since the sheet member 9 extends in the axial direction δ of the photoreceptor drum 23 and is attached along the axial direction δ to the end face portion 81 facing the photoreceptor drum 23, the sheet member 9 can be attached even more easily from the photoreceptor drum 23 side (i.e., from outside the housing 8), and the sheet member 9 can be stably held in the axial direction δ of the photoreceptor drum 23.

[0056] Furthermore, as described above, since the adhesive portion 93 is provided in the middle of the sheet member 9 in the direction along the rotation direction R of the photoreceptor drum 23, the difference between the distance between the adhesive portion 93 and the light diffusion portion 92 and the distance between the adhesive portion 93 and the toner receiving portion 94 can be reduced compared to the case where the adhesive portion 93 is provided at one end in the direction along the rotation direction R of the photoreceptor drum 23. As a result, the positional variation of both the light diffusion portion 92 and the toner receiving portion 94 with respect to the adhesive portion 93 can be reduced compared to the case where the adhesive portion 93 is provided at one end in the direction along the rotation direction R of the photoreceptor drum 23.

[0057] Although one embodiment of the present disclosure has been described above, the invention is not limited to that described above, and the following modifications may be adopted. (Variation 1) Figure 6 is a schematic cross-sectional view showing another example of the sheet member 9. In Figure 6, for illustrative purposes, the thickness of the sheet member 9 is exaggerated, and the surface 90 and back surface 91 of the sheet member 9 are also exaggerated to conceptually show the roughness of the surface 90 and back surface 91.

[0058] As conceptually shown in Figure 6, the roughness of the front surface 90 and back surface 91 of the sheet member 9 may be uniform overall. This allows the sheet member 9 to be easily manufactured using a uniform material. For example, the sheet member 9 may contain light-diffusing particles and a resin binder throughout the outer layer (reference numerals omitted) of the back surface 91. In other words, not only the light-diffusing portion 92, but also the adhesive portion 93 and the toner receiving portion 94 may each contain light-diffusing particles and a resin binder in the outer layer (reference numerals omitted) on the back side.

[0059] In this case, it is preferable that the surface 90 of the sheet member 9 is smoother than the back surface 91. As a result, the outer surface of the contact portion 940, which constitutes a part of the surface 90 of the sheet member 9, is smoother than the back surface 91 of the sheet member 9. This makes it possible to more reliably suppress the scattering of residual toner removed by the cleaning blade 260 (not shown in Figure 6) from between the photoreceptor drum 23 and the toner receiving portion 94 to the outside of the cleaning device 26, similar to the case described above where the outer surface of the contact portion 940 is smoother than the outer surface of the outer layer 920 of the light diffusion portion 92.

[0060] (Other variations) The sheet member 9 is not limited to the above, and may be attached to the end face portion 81 by fastening members such as screws. The sheet member 9 is not limited to the above, and may be attached to the housing 8 upstream of the photoreceptor drum 23 in the rotation direction R, or at both ends in the axial direction δ, depending on the layout (arrangement) of the static elimination device 25 and the cleaning device 26 in the process unit P. The light diffusion portion 92 is not limited to the above, and may contain light diffusion particles and a resin binder in the outer layer (reference numeral omitted) on the surface side.

[0061] The embodiments described above are illustrative in all respects and are not intended to be restrictive. Therefore, the technical scope of this disclosure is not construed solely by the embodiments and examples described above, but is defined by the claims. Furthermore, any modifications or changes within the equivalent scope of the claims are all within the scope of this disclosure. [Explanation of symbols]

[0062] 1. Image forming apparatus P Process Unit 23 Photoconductor drum 230 Outer surface 25 Static eliminator 250 light source 251 Light guide member 26 Cleaning device 260 Cleaning Blade (Cleaning Part) α Contact point 6. Light Diffusion Sheet 7. Toner receiving sheet 8 Housing 80 Intermediate wall 81 End section 9 Sheet members 92 Light Diffusion Section 920 outer layer 93. Attachment area 94 Toner receiving section 940 Contact area R rotation direction δ axis direction

Claims

1. A process unit comprising: an anti-static device that removes residual charge from the outer surface of a photoreceptor drum by irradiating the outer surface of the photoreceptor drum with light; and a cleaning device provided adjacent to the anti-static device downstream in the rotational direction of the photoreceptor drum, for collecting residual toner from the outer surface of the photoreceptor drum, The static elimination device comprises a light source and a light guide member that guides the light from the light source to the photosensitive drum. A light-diffusing sheet is provided between the light-guide member and the photoreceptor drum to diffuse the light from the light-guide member. The cleaning device includes a cleaning member that removes the residual toner by contacting the outer surface of the photoreceptor drum. In the cleaning apparatus, a toner receiving sheet is provided upstream of the contact point between the photoreceptor drum and the cleaning member in the direction of rotation of the photoreceptor drum, to prevent the residual toner removed by the cleaning member from scattering outside the cleaning apparatus. A process unit in which the light-diffusing sheet and the toner receiving sheet are configured as a single continuous sheet member so as to be arranged in this order along the rotation direction of the photoreceptor drum.

2. In the process unit according to claim 1, The static elimination device and the cleaning device are housed in a housing. The housing is provided with an end face portion that extends in the axial direction of the photoreceptor drum and faces the photoreceptor drum. The sheet member is attached to the end face portion along the axial direction in a process unit.

3. In the process unit according to claim 2, The housing is provided with an intermediate wall that extends in the axial direction between the static elimination device and the cleaning device and has an end face portion. A process unit in which the adhesive portion attached to the end face of the sheet member is provided between the light-diffusing portion, which functions as the light-diffusing sheet, and the toner-receiving portion, which functions as the toner-receiving sheet.

4. In the process unit according to claim 2, The light-diffusing portion of the sheet member, which functions as the light-diffusing sheet, contains light-diffusing particles and a resin binder in its outer layer. A process unit in which the outer surface of the adhesive portion attached to the end face of the sheet member is smoother than the outer surface of the outer layer of the light diffusing portion.

5. In the process unit according to claim 2, The light-diffusing portion of the sheet member, which functions as the light-diffusing sheet, contains light-diffusing particles and a resin binder in its outer layer. The toner receiving portion of the sheet member, which functions as the toner receiving sheet, has a contact portion that contacts the outer surface of the photoreceptor drum. A process unit in which the outer surface of the contact portion is smoother than the outer surface of the outer layer of the light diffusion portion.

6. An image forming apparatus comprising the process unit described in claim 1.

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