Image forming apparatus and positioning components used therein

Abstract

To determine the position of image holding means including an image holding body that requires grounding inside an apparatus housing in such a manner that the image holding means is allowed to be grounded and the position of one end of the image holding means is determined relative to a support frame with one component for positioning.SOLUTION: An image forming apparatus comprises: positioning means 5 that is provided at part of an edge of a support opening 4a of a support frame 4, and when image holding means 1 is mounted in an apparatus housing, determines the position of part of a holding frame 3 of the image holding means 1 relative to the support frame 4; and a component for positioning 6 having a mounted part 8 that is formed of an elastically deformable elastic member 7 having conductivity and is removably mounted at one end of the image holding means 1, and an urging part 9 that is integrally formed with the mounted part 8, is provided at a portion for ensuring the conduction between a conductive substrate 2b of an image holding body 2 and the support frame 4, and urges the image holding means 1 in a direction to intersect a rotation shaft 2c of the image holding body 2 to allow the positioning means 5 to perform the positioning.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an image forming apparatus and a positioning component used therefor.

Background Art

[0002] Conventionally, as this type of image forming apparatus, for example, those described in Patent Documents 1 to 3 are already known. Patent Document 1 discloses a transfer device that is grounded and can move freely in the vertical direction by tension applying members provided at both ends of a transferrer and a separation member, and when the transfer device is mounted, both ends abut against positioning members provided on the main body side. Patent Document 2 discloses a process cartridge that uses a bearing cover to hold without play a second ground contact for connecting a drum shaft disposed in a cleaning frame body and a main body side contact point. Patent Document 3 discloses an image forming apparatus having a cylindrical conductive base material, a photosensitive drum rotatably supported with respect to a cartridge case of an image forming cartridge, a conductive resin flange fixed to one end of the photosensitive drum, a rotation transmission means disposed at the other end of the photosensitive drum for generating a thrust force by rotation transmitted from a drive source to the photosensitive drum, a shaft member made of a conductor, extending through the flange and having a contact surface with the flange, and a biasing means that contacts the shaft member, is disposed on a frame of the image forming apparatus and grounded, and biases the shaft member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

[0004] The technical problem that the present invention aims to solve is to position an image holding means, which includes an image holder that requires grounding within the device housing, by positioning one end of the image holding means with respect to a support frame using a single positioning component, and also enabling grounding. [Means for solving the problem]

[0005] The invention according to claim 1 is an image forming apparatus characterized by comprising: an image holding means having an image holder detachably provided to a device housing and having a charge-holding layer provided on a conductive substrate, and a holding frame for rotatably holding the image holder; a support frame provided at one end of the image holding means in the rotation axis direction of the image holder, made of a conductive material and having a support opening capable of supporting one end of the image holding means; a positioning means provided at a part of the edge of the support opening of the support frame for positioning a part of the holding frame of the image holding means with respect to the support frame when the image holding means is mounted on the device housing; a mounting portion made of an elastically deformable conductive elastic material and detachably mounted at one end of the image holding means; and a positioning component integrally formed with the mounting portion and provided at a part that ensures electrical conductivity between the conductive substrate of the image holder and the support frame, and biasing the image holding means in a direction intersecting the rotation axis direction of the image holder so as to enable positioning by the positioning means.

[0006] The invention according to claim 2 includes an image holding means having an image holder detachably mounted to a device housing and having a charge-holding layer provided on a conductive substrate, and a holding frame for rotatably holding the image holder; a support frame provided at one end of the image holding means in the rotation axis direction of the image holder, made of a conductive material, and having a support opening capable of supporting one end of the image holding means; and a positioning means provided at a part of the edge of the support opening of the support frame for positioning a part of the holding frame of the image holding means relative to the support frame when the image holding means is mounted to the device housing. The image forming apparatus is characterized by comprising: a positioning component having an elastic member having elastic deformation properties and being electrically conductive, which is detachably attached to one end of the image holding means; a biasing portion formed integrally with the mounting portion and provided in a portion that ensures electrical conductivity between the conductive base of the image holder and the support frame, which biases the image holding means in a direction intersecting the rotation axis direction of the image holder so as to enable positioning by the positioning means; and another biasing portion formed integrally with the mounting portion or the biasing portion, which biases the image holding means in the rotation axis direction of the image holder.

[0007] The invention according to claim 3 is an image forming apparatus according to claim 1 or 2, characterized in that the positioning component is made of a leaf spring. The invention according to claim 4 is an image forming apparatus according to claim 3, characterized in that the positioning component is configured such that one side region of the leaf spring is bent into a substantially U-shape in cross-section to form the mounting portion, and the other side region is bent into a substantially U-shape in cross-section on the opposite side from the mounting portion to form the biasing portion. The invention according to claim 5 is an image forming apparatus according to claim 1 or 2, characterized in that the mounting portion embraces and holds a portion to be mounted that is pre-formed at one end of the image holding means. The invention according to claim 6 is an image forming apparatus according to claim 5, characterized in that the mounting portion has a structure that can be positioned on a positioning portion that is pre-formed on the portion to be mounted. The invention according to claim 7 is an image forming apparatus according to claim 5, characterized in that the mounting portion has a retaining portion (retaining hole) related to a retaining portion that is formed in advance on the portion to be mounted. The invention according to claim 8 is an image forming apparatus according to claim 5, characterized in that the mounting portion is arranged in a manner that is not in contact with the edge of the support opening of the support frame and the positioning means. The invention according to claim 9 is an image forming apparatus according to claim 1 or 2, characterized in that the biasing portion contacts and compresses between a part of the conductive substrate of the image holder and the edge of the support opening of the support frame located on the opposite side from the positioning means, thereby biasing the image holder toward the positioning means. The invention according to claim 10 is an image forming apparatus according to claim 9, characterized in that the biasing portion is arranged such that the contact portion on the image holding means side and the contact portion on the support frame side coincide in the rotation axis direction of the image holder. The invention according to claim 11 is an image forming apparatus according to claim 9, characterized in that the biasing portion has an elastic biasing force greater than the elastic holding force of the mounting portion. The invention according to claim 12 is an image forming apparatus according to claim 1 or 2, characterized in that the positioning component is a retrofittable leaf spring. The invention according to claim 13 is an image forming apparatus according to claim 12, characterized in that the leaf spring has a covering portion that covers the edge of the support opening of the support frame. The invention according to claim 14 is an image forming apparatus according to claim 12, characterized in that it has an outer cover on the outside of the support opening of the support frame that covers the tip of the leaf spring and the edge of the support opening from the outside. The invention according to claim 15 is, 2 In the image forming apparatus relating to the above, the positioning component is Add-onThe image forming apparatus is characterized by being made of a leaf spring, with the biasing portion and the other biasing portion being integrally formed in a bifurcated manner relative to the mounting portion, the biasing portion being bent into a U-shape in cross-section, and the other biasing portion being straight-extending, and the tip sides of the biasing portion and the other biasing portion being positioned in contact with the edge of the support opening of the support frame.

[0008] The invention according to claim 16 is a positioning component used in an image forming apparatus, comprising: an image holding means detachably mounted to an apparatus housing and having an image holder having a charge-holding layer provided on a conductive substrate, and a holding frame for rotatably holding the image holder; a support frame provided at one end of the image holding means in the rotation axis direction of the image holder, made of a conductive material and having a support opening capable of supporting one end of the image holding means; and a positioning means provided at a part of the edge of the support opening of the support frame for positioning a part of the holding frame of the image holding means with respect to the support frame when the image holding means is mounted to the apparatus housing, wherein the positioning component is made of an elastically deformable conductive elastic material and is located at one end of the image holding means A pre-formed mounting portion A mounting portion that is detachably attached, and a portion formed integrally with the mounting portion, The image holder has a portion that contacts the conductive substrate and the edge of the support opening of the support frame at two locations. Ensuring electrical conductivity between the conductive substrate of the image holder and the support frame. together , so as to enable positioning by the positioning means image holder A positioning component characterized by having a biasing portion that biases the image holding means in a direction intersecting the rotation axis direction. [Effects of the Invention]

[0009] According to the invention of claim 1, when positioning an image holding means that includes an image holder requiring grounding within the device housing, one end of the image holding means can be positioned relative to the support frame with a single positioning component, and grounding can be made possible. According to the invention of claim 2, when positioning an image holding means that includes an image holder requiring grounding within the device housing, one end of the image holding means can be positioned relative to the support frame with a single positioning component, and grounding is possible. In particular, the image holding means can be positioned in two directions: the rotation axis direction and a direction intersecting the rotation axis direction. According to the invention of claim 3, the elements necessary for positioning can be easily constructed compared to the case where an elastic member other than a leaf spring is used. According to the invention of claim 4, the mounting portion and biasing portion necessary as positioning components can be easily constructed. According to the invention of claim 5, a positioning component can be easily attached to one end of the image holding means. According to the invention of claim 6, a positioning component can be easily attached to a predetermined position at one end of the image holding means. According to the invention of claim 7, a positioning component can be attached to one end of the image holding means in a manner that prevents it from coming off. According to the invention of claim 8, a positioning component can be attached to one end of the image holding means without interfering with the support frame and the positioning means. According to the invention of claim 9, positioning one end of the image holding means so that it can be grounded with respect to the support frame can be achieved by devising the configuration of the biasing portion of a single positioning component. According to the invention of claim 10, it is possible to accurately set the biasing direction by the biasing portion of the positioning component. According to the invention of claim 11, it is possible to easily ensure sufficient elastic biasing force by the biasing portion of the positioning component. According to the invention of claim 12, one end of the image holding means can be positioned relative to the support frame without impairing the ease of assembling the image holding means relative to the support frame. According to the invention of claim 13, the leaf spring, which is a positioning component, is provided with a covering function and can be hidden at the edge of the support opening of the support frame. According to the invention according to claim 14, an outer cover can be added to the support frame, and the end of the leaf spring, which is a positioning component exposed on the support opening side, and the edge of the support opening of the support frame can be hidden. According to the invention according to claim 15, when positioning one end of the image holding means with respect to the support frame using one positioning component and making it groundable, one end of the image holding means can be positioned in both the direction of the rotation axis of the image holder and the direction intersecting the rotation axis direction. According to the invention according to claim 16, when positioning the image holding means including an image holder that requires grounding in the apparatus housing, positioning one end of the image holding means with respect to the support frame and making it groundable can be realized with one positioning component.

Brief Description of the Drawings

[0010] [Figure 1] (a) is an explanatory diagram showing an overview of an embodiment of an image forming apparatus to which the present invention is applied, and (b) is an explanatory diagram showing a configuration example of a positioning component. [Figure 2] It is an explanatory diagram showing the overall configuration of the image forming apparatus according to Embodiment 1. [Figure 3] It is an explanatory diagram showing an example of a process cartridge used in Embodiment 1. [Figure 4] It is an explanatory diagram showing an example of an image forming engine used in Embodiment 1. [Figure 5] It is an explanatory diagram showing the positioning structure of the process cartridge used in Embodiment 1. [Figure 6] It is an explanatory diagram showing the positioning component and its mounting part used in FIG. 5. [Figure 7] It is a front explanatory diagram of the positioning structure of the process cartridge shown in FIG. 5. [Figure 8] It is a cross-sectional explanatory diagram of the positioning structure of the process cartridge shown in FIG. 5. [Figure 9] It is an explanatory diagram showing the positioning action and grounding action by the positioning component. [Figure 10](a) is an explanatory diagram showing the end of the process cartridge and the support opening of the support frame before the positioning component according to Embodiment 2 is attached, and (b) is an explanatory diagram showing the state in which the positioning component according to Embodiment 2 is attached to the end of the process cartridge. [Figure 11] This is a cross-sectional explanatory diagram showing the mounting state of the positioning component according to Embodiment 2. [Figure 12] This is a cross-sectional explanatory diagram showing the mounting state of the positioning component according to Embodiment 3. [Figure 13] (a) is an explanatory diagram showing the positioning component according to Example 1 attached to the end of the process cartridge, and (b) is a perspective explanatory diagram showing the positioning component used in (a). [Figure 14] This is an explanatory diagram showing the dimensions of the positioning components used in Example 1. [Figure 15] (a) is an explanatory diagram showing the positioning structure of a process cartridge according to Comparative Example 1, and (b) is an explanatory diagram showing the grounding state by the positioning component. [Modes for carrying out the invention]

[0011] ◎Overview of the Embodiment Figure 1(a) is an explanatory diagram showing an overview of an embodiment of an image forming apparatus to which the present invention is applied, and (b) is an explanatory diagram showing the main part of a positioning component, which is an element of the image forming apparatus. In the figure, the image forming apparatus has an image holding means 1 which is detachably mounted to an apparatus housing (not shown) and has an image holder 2 having a charge holding layer 2a on a conductive substrate 2b, and a holding frame 3 which rotatably holds the image holder 2, and a support frame 4 which is provided at one end of the image holding means 1 in the direction of the rotation axis 2c of the image holder 2, is made of a conductive material and has a support opening 4a that can support one end of the image holding means 1, and is provided at a part of the edge of the support opening 4a of the support frame 4 when the image holding means 1 is mounted to the apparatus housing. The system includes a positioning component 6 which has a positioning means 5 for positioning a part of the holding frame 3 of the image holding means 1 with respect to a support frame 4, a mounting portion 8 made of an elastically deformable conductive elastic member 7 that is detachably attached to one end of the image holding means 1, and a biasing portion 9 which is integrally formed with the mounting portion 8 and provided in a part that ensures electrical conductivity between the conductive base 2b of the image holder 2 and the support frame 4, and biases the image holding means 1 in a direction intersecting the rotation axis 2c direction of the image holder 2 so that it can be positioned by the positioning means 5.

[0012] In this example, another embodiment of the positioning component 6 is an embodiment (see Embodiment 3) which comprises an elastically deformable conductive elastic member 7 and includes a mounting portion 8 that is detachably attached to one end of the image holding means 1, a biasing portion 9 that is integrally formed with the mounting portion 8 and provided in a part that ensures electrical conductivity between the conductive base 2b of the image holder 2 and the support frame 4, and biases the image holding means 1 in a direction intersecting the rotation axis 2c direction of the image holder 2 so as to enable positioning by the positioning means 5, and another biasing portion (not shown) that is integrally formed with the mounting portion 8 or the biasing portion 9 and biases the image holding means 1 in the rotation axis 2c direction of the image holder 2. In the embodiment shown in Figure 1(a), the other end of the image holding means 1 is positioned on the opposite support frame 11, for example, with the holding frame 3 positioned on the opposite side via the opposite positioning means 12, and the rotation axis 2c of the image holder 2 is configured to receive driving force from the drive source 13 via a coupling.

[0013] In such technical means, the image holding means 1 is primarily envisioned as a unitized system of multiple parts such as a photoreceptor, charger, and cleaner, like a process cartridge, but also includes at least an image holder 2 and a holding frame 3. The image holder 2 referred to here is This broadly includes devices having a charge-holding layer 2a (such as a photosensitive layer or dielectric layer) on a conductive substrate 2b. Furthermore, the support frame 4 broadly includes not only the housing frame that constitutes the device housing, but also, for example, the engine frame of an imaging engine that integrates multiple process cartridges, and the module frame of an intermediate transfer module mounted on the device housing. Furthermore, as a specific example of the positioning means 5, a positioning projection is provided on the support frame 4 side, for example, inclined in an inverted V shape, and a positioning portion that contacts the positioning projection is pre-formed on the holding frame 3 of the image holder 2. However, if the positioning is performed in a rotation-preventing state, a structure in which a positioning recess and a positioning protrusion fit together is also acceptable. Furthermore, the positioning component 6 can be appropriately selected as long as it is composed of an elastic member 7. Furthermore, the biasing portion 9 may also serve as a conductive portion (earth structure), and the other biasing portion is not limited to the mounting portion 8, but may be integrated with the biasing portion 9.

[0014] Next, a typical or preferred embodiment of the positioning component 6 in this embodiment will be described. First, a typical example of a positioning component 6 is one in which it is composed of a leaf spring. In this example, the positioning component 6 can be configured such that one side of the leaf spring is bent into a roughly U-shape in cross-section to form the mounting portion 8, and the other side is bent into a roughly U-shape in cross-section on the opposite side from the mounting portion 8 to form the biasing portion 9. Furthermore, a typical embodiment of the mounting portion 8 is one in which it embraces and holds a portion to be mounted that is pre-formed on one end of the image holding means 1. In this example, it is preferable that the mounting portion 8 has a structure that allows it to be positioned on a positioning portion (positioning groove, positioning boss) that is pre-formed on the part to be mounted. It is also preferable that the mounting portion 8 has a retaining portion (retaining hole) that is related to a retaining portion (retaining projection) that is pre-formed on the part to be mounted. Furthermore, it is preferable that the mounting portion 8 is positioned so as not to be in contact with the edge of the support opening 4a of the support frame 4 and the positioning means 5.

[0015] Furthermore, a typical embodiment of the biasing portion 9 is one in which a part of the conductive substrate 2b of the image holder 2 and the edge of the support opening 4a of the support frame 4 located on the opposite side from the positioning means 5 come into contact and compress and deform, thereby biasing the image holder 1 toward the positioning means 5. In a preferred embodiment of this example, the biasing portion 9 is positioned such that the contact point on the image holding means 1 side and the contact point on the support frame 4 side coincide in the direction of the rotation axis 2c of the image holder 2. Furthermore, the biasing portion 9 is preferably elastically biased greater than the elastic holding force of the mounting portion 8.

[0016] Furthermore, a preferred embodiment of the positioning component 6 is a leaf spring that can be added later, from the viewpoint of not impairing the ease of assembling the image holding means 1 with respect to the support frame 4. In this example, if the edge of the support opening 4a of the support frame 4 is structured in a way that makes it easily damaged by the user, the leaf spring may have a covering portion that covers the edge of the support opening 4a of the support frame 4. Furthermore, if the tip of the leaf spring is exposed facing the support opening 4a, it is preferable that the support frame 4 has an outer cover 14 on the outside of the support opening 4a that covers the tip of the leaf spring and the edge of the support opening 4a from the outside. Furthermore, in an embodiment in which another biasing part is provided in addition to the biasing part 9, it is preferable that the positioning component 6 is made of a leaf spring, and that the biasing part 9 and the other biasing part are integrally formed with respect to the mounting part 8 by dividing them into two branches, with the biasing part 9 having a U-shaped cross-section and the other biasing part having a straight-line extension, and that the tip sides of the biasing part 9 and the other biasing part are positioned in contact with the edge of the support opening 4a of the support frame 4.

[0017] The present invention will be described in more detail below based on the embodiments shown in the attached drawings. ◎Embodiment 1 Figure 2 shows the overall configuration of the image forming apparatus according to Embodiment 1. -Overall configuration of the image forming apparatus- In the figure, the image forming apparatus 20 is equipped with an image forming engine 30 that forms images of multiple colors (in this embodiment, four colors: yellow, magenta, cyan, and black) inside the apparatus housing 21. An intermediate transfer module 40 in which a belt-shaped intermediate transfer body 45 circulates is provided above the image forming engine 30, while a media supply device 50 that houses a medium such as paper is provided below the image forming engine 30. A media transport path 51 from the media supply device 50 is arranged in a substantially vertical direction, and a transfer device 60 that transfers the image held by the intermediate transfer body 45 to the medium is installed in the portion of the media transport path 51 facing the intermediate transfer body 45. Furthermore, a fixing device 70 that fixes the image transferred to the medium is installed downstream of the transfer device 60 in the media transport path 51.

[0018] <Image Creation Engine> In this example, the image forming engine 30 is an image forming unit 31 (specifically) that forms an image of multiple colors. In essence, elements 31a to 31d are arranged in a roughly horizontal direction. Here, each image forming unit 31 (31a to 31d) forms toner images in order from the upstream side in the circulation direction of the intermediate transfer body 45, for example, for yellow, magenta, cyan, and black (the order is not necessarily this order), and includes a photoreceptor 32, a charger 33 for pre-charging the photoreceptor 32, an optical writing head 34 for writing electrostatic latent images to each photoreceptor 32 charged by the charger 33, a developer 35 for developing the electrostatic latent images formed on the photoreceptor 32 with the corresponding color component toner (for example, negative polarity in this embodiment), and a cleaner 36 for cleaning residue on the photoreceptor 32. Furthermore, the symbols 37 (specifically 37a to 37d) are toner cartridges for supplying each color component toner to each developer unit 35.

[0019] <Intermediate Transfer Module> Furthermore, in this embodiment, the intermediate transfer module 40 has a belt-shaped intermediate transfer body 45 stretched across a plurality of tension rolls 41 to 44, and for example, the tension roll 41 is used as a driving roll to circulate the intermediate transfer body 45. Furthermore, a primary transfer device (a transfer roll in this example) 46 is provided on the back surface of the intermediate transfer body 45 corresponding to the photoreceptor 32 of each image forming unit 31. By applying a transfer voltage with the opposite polarity to the charging polarity of the toner to this transfer device 46, the toner image on the photoreceptor 32 is electrostatically transferred to the intermediate transfer body 45. Furthermore, an intermediate transfer body cleaner 47 is provided upstream of the uppermost image forming section 31a of the intermediate transfer body 45 to remove any residual toner on the intermediate transfer body 45.

[0020] <Transfer device> Furthermore, in this embodiment, a transfer device 60 is provided in the area corresponding to the tensioned roll 42 downstream of the downstream image forming section 31d of the intermediate transfer body 45, and is configured to transfer the primary transfer image on the intermediate transfer body 45 to a medium. In this example, the transfer apparatus 60 includes a transfer roll 61 that is pressed against the toner image holding surface side of the intermediate transfer body 45, and a backup roll (which also serves as the tensioning roll 42 in this example) that is positioned on the back side of the intermediate transfer body 45 and acts as the counter electrode for the transfer roll 61. For example, the transfer roll 61 is grounded, and a transfer voltage with the same polarity as the charge polarity of the toner is applied to the backup roll (tensioning roll 42). <Fusing device> In this embodiment, the fixing device 70 includes a rotatable heating fixing member (in this example, a heating fixing roll is used) 71 whose surface temperature is heated to a predetermined temperature by a heater as a heat source, and a pressure fixing member (in this example, a pressure fixing roll is used) 72 that contacts and rolls along the axial direction of the heating fixing member 71 with a predetermined contact pressure. The unfixed image is fixed by passing a medium holding the unfixed image through the contact area of ​​both fixing members 71 and 72.

[0021] <Media transport system> In this example, the media supply device 50 is equipped with two media supply units 50a and 50b. The number and layout of the media supply units may be modified as appropriate, and a manual feed type media supply unit may be added if necessary. In this example, a media transport path 51 extending approximately vertically is provided on the left side of the device housing 21. The media supplied from the media supply device 50 is transported along the media transport path 51 by a transport roll 52, aligned by an alignment roll 53 located before the transfer area between the intermediate transfer body 45 and the transfer device 60, and then transported to the transfer area. After undergoing the image transfer process on the intermediate transfer body 45, the media passes through the transfer area of ​​the fixing device 70 to undergo the image fixing process. The media that has undergone the fixing process by the fixing device 70 is then collected in a media discharge receiver 56 formed in the device housing 21 via a discharge roll 55. Furthermore, the media discharge receiver 56 can be appropriately redesigned according to the media discharge position, and although this example employs a media transport system that forms an image on one side of the media, a double-sided transport module can be added, for example, to form an image on both sides of the media.

[0022] -Example of process cartridge configuration- In this embodiment, the image forming unit 31 (31a to 31d) is configured as a process cartridge 100 (corresponding to the "image holding means" in Figure 1) that positions and holds each of the devices, the photoreceptor 32, the charger 33, the optical writing head 34, the developer 35, and the cleaning unit 36, in a single cartridge housing 110 (corresponding to the "holding frame" in Figure 1), as shown in Figure 3. In this example, the process cartridge 100 is positioned below the transfer unit 46 of the intermediate transfer module 40. The photoreceptor 32 is positioned opposite the transfer unit 46, and the charger 33 is positioned approximately directly below the photoreceptor 32. Furthermore, the optical writing head 34 and the developer 35 are positioned along the rotational direction of the photoreceptor 32, while the cleaning unit 36 ​​is positioned upstream of the charger 33 in the rotational direction of the photoreceptor 32. The devices to be unitized as the process cartridge 100 may be selected as appropriate.

[0023] Here, the photoreceptor 32 has a conductive substrate 32b formed in a drum shape from, for example, a conductive material, and a photosensitive layer 32a (corresponding to the "charge holding layer" in Figure 1) is formed on the surface of this conductive substrate 32b, and a rotation axis 32c is provided at the rotation center portion of the conductive substrate 32b. Furthermore, in this example, the charger 33 is one in which a charging voltage is applied from a power supply roll 33b to a charging roll 33a that contact charges the photoreceptor 32. However, it is not limited to this, and a non-contact charging device such as a Corotron or Scorotron may also be used. Furthermore, in this example, the optical writing head 34 is configured to write separately to each photoreceptor 32 using an LED writing head. However, it is not limited to this configuration. Alternatively, a shared laser scanner may be provided to write the electrostatic latent image of each color component to each photoreceptor 32 using the corresponding laser light, or separate laser scanners may be provided for each. However, when using a laser scanner, it is usually installed outside the process cartridge 100. Furthermore, as shown in Figure 3, the developing unit 35 has a developing container 35a that contains a developer including toner and carrier and has an opening facing the photoreceptor 32. A developing roll 35b is placed at the opening of the developing container 35a, and the developing roll 35b holds the developer and supplies the developer to the part facing the photoreceptor 32. Stirring and conveying members 35c and 35d are placed inside the developing container 35a for stirring and charging the developer while conveying it. In addition, a regulating member 35e is placed around the developing roll 35b to regulate the amount of developer supplied to the developing roll 35b. In this example, the cleaning device 36 has a cleaning container 36a that contains residue on the photoreceptor 32 and has an opening facing the photoreceptor 32. A cleaning blade 36b, which serves as a plate-shaped cleaning member for scraping off residue on the photoreceptor 32, is attached to the opening edge of the cleaning container 36a, and an agitation and conveying member 36c is provided inside the cleaning container 36a to convey the contained residue in a leveling manner.

[0024] -Example configuration of a 3D modeling engine- In this embodiment, if the user-operated side of the image forming apparatus 20 is considered the front side and the opposite side the rear side, the image forming engine 30 supports a process cartridge 100, which is a unit comprising each image forming section 31 (31a to 31d), on a pair of front and rear support frames 120 (front support frame 120f, rear support frame 120r), as shown in Figure 4. The support frames 120 are made of conductive material and are grounded. In this example, the front end of the process cartridge 100 (containing the image forming units 31a to 31d) is positioned on the front support frame 120f via a positioning component 122, utilizing a substantially circular support opening 121 provided in the front support frame 120f. Further details on this will be provided later. On the other hand, the rear end of the process cartridge 100 is positioned relative to the rear support frame 120r via a positioning mechanism 123, and the rotation axis 32c of the photoreceptor 32 is connected to the drive source 125 via a coupling (not shown). Here, the positioning mechanism 123 consists of a positioning pin 124 protruding from the rear end of the cartridge housing 110 of the process cartridge 100, a positioning emboss (not shown) formed on the rear support frame 120r, and the positioning pin 124 being fitted into this positioning emboss.

[0025] - Front-side positioning structure of the process cartridge - In this example, the structure of the front end of the process cartridge 100 will be described first. As shown in Figures 5 to 8, a through hole 130 larger than the outer diameter of the rotation axis 32c of the photoreceptor 32 is provided in the front side wall 111 of the cartridge housing 110. A resin protective cover 131 that covers the end of the photoreceptor 32 is fitted into this through hole 130, and the rotation axis 32c of the photoreceptor 32 is rotatably supported by this protective cover 131 via a bearing part (not shown), and is positioned to protrude outward from the front side wall 111 of the cartridge housing 110.

[0026] <Protective cover> In this example, the protective cover 131 has a protruding portion 132 that extends outward from the front side wall 111 of the cartridge housing 110 to cover the upper half of the rotation axis 32c of the photoreceptor 32. The protective cover 131 also has a mounting piece 133 that protrudes downward for fixing to the front side wall 111 of the cartridge housing 110. In this example, the protruding portion 132 has a mountain-shaped enclosure portion 135 that surrounds the upper part of the rotation axis 32c of the photoreceptor 32 in a roughly mountain-shaped manner, without contact with the rotation axis 32c of the photoreceptor 32, a lateral connecting portion 136 that connects the lower part of the protruding end of the mountain-shaped enclosure portion 135, and a vertical connecting portion 137 that connects the center of the mountain-shaped enclosure portion 135 and the center of the lateral connecting portion 136 in the vertical direction. Furthermore, the area near the center of the mountain-shaped enclosure portion 135 is formed as a flat portion 138, and curved portions 139 are formed on both sides of the flat portion 138 of the mountain-shaped enclosure portion 135.

[0027] -Positioning mechanism- In this example, the positioning mechanism 150 at the front end of the process cartridge 100 is formed between the edge of the support opening 121 of the front support frame 120f and the aforementioned protective cover 131, as shown in Figure 7. In this example, the support opening 121 of the front support frame 120f is formed in a substantially circular shape. However, as shown in Figure 7, the edges of the support opening 121 at approximately 45 degrees diagonally upward to the right and approximately 45 degrees diagonally to the left are straight, forming a pair of positioning walls 151 and 152 arranged in an inverted V shape.

[0028] -Positioning parts- <Basic configuration of positioning components> In this example, the positioning component 122 is, as shown in Figures 5 to 10, an elastically deformable conductive elastic member, for example, a leaf spring 160 made of SUS steel. Here, the positioning component 122 must have a mounting portion 161 that can be attached to a part of the front end of the process cartridge 100, and a biasing portion 162 that is integrally formed with the mounting portion 161 and is provided in a part that ensures electrical contact between the conductive substrate 32b of the photoreceptor 32 and the front support frame 120f, and biases the process cartridge 100 in a direction intersecting the rotation axis 32c direction of the photoreceptor 32 (vertically upward in this example) so that it can be positioned by the positioning mechanism 150. Therefore, in this example, as shown in Figure 6, the positioning component 122 is configured by bending one side of the leaf spring 160 into a roughly U-shaped cross-section to form the mounting portion 161, and bending the other side of the leaf spring 160 into a roughly U-shaped cross-section on the opposite side from the mounting portion 161 to form the biasing portion 162.

[0029] -Example of leaf spring configuration- More specifically, the mounting portion 161 of the leaf spring 160 has a straight body portion 611 extending in the vertical direction, an upper hook portion 612 bent at approximately a right angle from the upper end of the straight body portion 611, and an intermediate hook portion 613 bent at an angle greater than a right angle from the lower end of the straight body portion 611. On the other hand, the biasing portion 162 of the leaf spring 160 has a bent body portion 621 that is bent in a roughly U-shape (in this example, a U-shape close to a roughly V-shape) from the middle of the intermediate hook portion 613, a lower hook portion 622 that is bent in a roughly horizontal direction from the lower end of the bent body portion 621, and a hem portion 623 that is folded in at the tip of the lower hook portion 622. In this example, a circular hole 614 is formed near the vertical center of the straight body portion 611. This hole 614 is used when it is necessary to temporarily suspend and store the leaf spring 160 when it is not in use. Additionally, a suitable number of slits 624 are formed in the bent body portion 621. These slits 624 are intended to secure multiple electrical contacts between the rotation axis 32c of the photoreceptor 32 and the front support frame 120f. Increasing the number of electrical contacts in this way is preferable because it ensures conductivity even if some contacts are interrupted due to factors such as separation from the front support frame 120f caused by disturbances.

[0030] In this example, the mounting portion 161 is designed to embrace and hold the mounting portion 140, which is provided on a part of the protective cover 131 of the photoreceptor 32. Here, the mounting portion 140 of the protective cover 131 uses the flat portion 138 of the protruding portion 132 as the upper hook portion, and the lower side surface of the rotation axis 32c of the photoreceptor 32 as the lower hook portion. For this reason, when the mounting portion 161 of the leaf spring 160 embraces and holds the mounting portion 140, it is sufficient that the upper hook portion 612 and the intermediate hook portion 613 of the mounting portion 161 deform in a direction that compresses it.

[0031] Furthermore, in order to improve the ease with which the leaf spring 160 can be attached to the mounting portion 140 of the protective cover 131, in this embodiment, a positioning recess 141 is formed in the area of ​​the flat portion 138 of the protruding end of the mountain-shaped enclosure portion 135, the lateral connecting portion 136, and the vertical connecting portion 137. In addition, a rectangular parallelepiped-shaped retaining projection 142 that protrudes upward is formed at the portion of the flat portion 138 that connects to the vertical connecting portion 137. On the other hand, the width dimension w1 of the straight body portion 611 of the mounting portion 161 of the leaf spring 160 is selected to be approximately equal to the width dimension w2 of the positioning recess 141, and a retaining hole 615 into which the retaining projection 142 can be inserted is formed at the boundary between the straight body portion 611 of the mounting portion 161 and the upper hook portion 612.

[0032] Furthermore, in this example, the biasing portion 162 contacts and compresses between a part of the conductive substrate 32b of the photoreceptor 32 (in this example, the rotation axis 32c of the photoreceptor 32 that is positioned in contact with the conductive substrate 32b) and the edge of the support opening 121 of the front support frame 120f that is located on the opposite side from the positioning walls 151 and 152 of the positioning mechanism 150, thereby biasing the process cartridge 100 toward the positioning walls 151 and 152 of the positioning mechanism 150. In other words, the biasing portion 162 should be such that the part of the bent body portion 621 closer to the intermediate hook portion 613 contacts the lower surface of the rotation axis 32c of the photoreceptor 32, and the lower hook portion 622 contacts the edge located below the support opening 121, thereby compressing the bent body portion 621 and applying a biasing force in the direction that reverses the compressive deformation.

[0033] - How to use positioning components - When using the positioning component 122, as shown in Figures 6 and 8, the mounting portion 161 of the leaf spring 160, which serves as the positioning component 122, is attached to the mounting portion 140 of the protective cover 131 of the photoreceptor 32, and the biasing portion 162 is positioned in contact with the lower surface of the rotation axis 32c of the photoreceptor 32, thereby temporarily holding the positioning component 122 in place on the protective cover 131. Here, when attaching the mounting portion 161 of the leaf spring 160 to the mounting portion 140 of the protective cover 131, the retaining hole 615 of the mounting portion 161 is hooked onto the retaining projection 142 of the mounting portion 140, the straight body portion 611 of the mounting portion 161 is fitted into the recess 141 of the mounting portion 140, and the intermediate hook portion 613 is pushed downward against the biasing force, and after inserting it into the space below the rotation axis 32c of the photoreceptor 32, the intermediate hook portion 613 of the mounting portion 161 is pressed against the lower surface of the rotation axis 32c of the photoreceptor 32. Thus, in this embodiment, the positioning component 122 is composed of a retrofittable leaf spring 160, so that the positioning component 122 can be retrofitted to the process cartridge 100 even during the assembly of the imaging engine 30.

[0034] In this state, the mounting portion 161 of the leaf spring 160 compresses and deforms the mounting portion 140 of the protective cover 131, embracing and holding it in place. Furthermore, the retaining structure provided by the retaining projection 142 and the retaining hole 615 ensures that the positioning component 122 is stably temporarily held in place on the mounting portion 140 of the protective cover 131, effectively preventing the positioning component 122 from unnecessarily detaching from the protective cover 131. Subsequently, when positioning each process cartridge 100 between the pair of support frames 120 (front support frame 120f, rear support frame 120r), as shown in Figures 4 and 8, each process cartridge 100 is first positioned relative to the rear support frame 120r via the positioning mechanism 123. Then, the lower hook portion 622 of the biasing portion 162 of the leaf spring 160, which is a positioning component 122 temporarily held by the protective cover 131, is pressed against the lower edge of the support opening 121 of the front support frame 120f. In this state, the positioning of the front end of the process cartridge 100 with respect to the front support frame 120f is completed.

[0035] -Positioning operation using positioning components- As described above, by inserting the positioning component 122 between the protective cover 131 of the photoreceptor 32 and the support opening 121 of the front support frame 120f, the positioning component 122 biases the front end of the process cartridge 100 against the positioning walls 151 and 152 of the positioning mechanism 150, thereby completing the positioning operation of the process cartridge 100. In this example, the positioning component 122 hooks the lower hook portion 622 of the biasing portion 162 of the leaf spring 160 onto the lower edge of the support opening 121. This causes the bent body portion 621 of the biasing portion 162 to compress and deform between the rotation axis 32c of the photoreceptor 32 and the lower edge of the support opening 121, thereby biasing the front end of the process cartridge 100 vertically via the protective cover 131. In this state, the protective cover 131 of the photoreceptor 32 is biased vertically, and a part of the protruding portion 132 of the protective cover 131, specifically the curved portion 139 of the mountain-shaped enclosure portion 135, abuts against the positioning walls 151 and 152 of the support opening 121. This restricts the upward and rotational movement of the front end of the process cartridge 100, and positions the front end of the process cartridge 100 relative to the edge of the support opening 121.

[0036] Here, since the mounting portion 161 is positioned in non-contact with the edge of the support opening 121 of the front support frame 120f and the positioning walls 151, 152, there is no concern whatsoever that the leaf spring 160, which is the positioning component 122, will interfere with the positioning operation of the process cartridge 100. Furthermore, in this example, the biasing force that biases the process cartridge 100 depends primarily on the amount of compression of the bent body portion 621 that constitutes the biasing portion 162 of the leaf spring 160 when the positioning component 122 is set. By adjusting the amount of compression of the bent body portion 621, it is possible to adjust the elastic biasing force F1 of the biasing portion 162 of the leaf spring 160.

[0037] Furthermore, if, for example, the contact point (contact 1) C1 between the upper end of the bent body portion 621 of the biasing portion 162 (in other words, the connection point with the intermediate hook portion 613 of the mounting portion 161) and the lower side surface of the rotation axis 32c of the photoreceptor 32, and the contact point (contact 2) C2 between the lower hook portion 622 and the lower edge of the support opening 121 of the front support frame 120f are offset in the direction of the rotation axis 32c of the photoreceptor 32, then the elastic biasing force F1 by the biasing portion 162 may act in the direction connecting the two contact points. However, normally the contact point with the lower edge of the support opening 121 is further outward from the rotation axis 32c of the photoreceptor 32 than the contact point with the rotation axis 32c of the photoreceptor 32, so the elastic biasing force F1 by the biasing portion 162 will not act in the direction of disengaging the leaf spring 160. In this example, as mentioned above, the mounting portion 161 is provided with a retaining structure, so even if the elastic biasing force F1 of the biasing portion 162 acts in a direction that would detach the leaf spring 160, there is no concern that the leaf spring 160 will come off unnecessarily.

[0038] However, if the contact points between the two by the biasing portion 162 are arranged to include a position where they coincide in the direction of the rotation axis 32c of the photoreceptor 32, the direction of action of the elastic biasing force F1 by the biasing portion 162 will be approximately vertical, which is preferable because it allows the elastic biasing force F1 directed in the vertical direction to be applied efficiently. Furthermore, when selecting the elastic holding force F3 by the mounting portion 161 of the leaf spring 160 and the elastic biasing force F1 by the biasing portion 162, it is acceptable to select them as appropriate. However, if the elastic holding force F3 by the mounting portion 161 is set too high, the mounting of the leaf spring 160 will be impaired, while if the elastic biasing force F1 by the biasing portion 162 is set too low, the positioning of the process cartridge 100 will become unstable. Therefore, it is preferable to adjust them so that the relationship is elastic biasing force F1 > elastic holding force F3.

[0039] Furthermore, as shown in Figure 8, if, for example, a part of the cartridge housing 110 or an internal device exists as an external protrusion 180 at the front end of the process cartridge 100, and this external protrusion 180 is in a positional relationship with the front support frame 120f, it is preferable to form a relief hole 181 in the front support frame 120f corresponding to the external protrusion 180 that is larger than the outer diameter of the external protrusion 180. In this case, in order to smoothly perform the positioning operation of the process cartridge 100 using the positioning component 122, it is preferable that the external projection 180 has some play with respect to the relief hole 181, and that the front end of the process cartridge 100 is not constrained by the front support frame 120f and is in a floating state before the positioning operation by the positioning component 122 is completed.

[0040] Furthermore, in this embodiment, as shown in Figure 8, the tip of the biasing portion 162 of the leaf spring 160 penetrates the support opening 121 of the front support frame 120f and is positioned to protrude outward from the outer surface of the front support frame 120f. However, since the tip of the biasing portion 162 is treated as a hem portion 623, there is absolutely no concern that the user will be injured even if they touch the tip of the biasing portion 162. Furthermore, if there is a need to avoid exposing the tip of the biasing portion 162 to the outside through the support opening 121, as shown in Figure 8, an outer cover 190, for example made of resin, may be detachably provided on the outer edge of the support opening 121 of the front support frame 120f to cover the tip of the biasing portion 162 of the leaf spring 160.

[0041] Furthermore, in this embodiment, the positioning component 122 biases the front end of the process cartridge 100 in a direction intersecting the rotation axis 32c direction of the photoreceptor 32 (vertical direction in this example) to position it. However, if there is a need to bias and position it in a direction along the rotation axis 32c direction of the photoreceptor 32, for example, as shown by dashed lines in Figure 9, a second spring member 200, such as a compression coil spring, may be interposed between the front end of the process cartridge 100 and the front support frame 120f, separately from the positioning component 122, to bias the front end of the process cartridge 100 toward the rear, thereby positioning it, for example, to a target location in the rotation axis direction pre-provided on the rear support frame 120r side.

[0042] -Also used as a grounding component for positioning parts- In this embodiment, the positioning component 122 biases the front end of the process cartridge 100 toward the support opening 121 of the front support frame 120f in a direction intersecting the rotation axis 32c of the photoreceptor 32 (vertically in this example), thereby performing a positioning function. In this example, the positioning component 122 also functions as a grounding component. Specifically, the positioning component 122 is composed of a leaf spring 160 made of a conductive elastic material. As shown in Figure 8, for example, the bent body portion 621, which is the biasing portion 162, of the leaf spring 160 is in contact with the rotation axis 32c of the photoreceptor 32, and the lower hook portion 622, which is the biasing portion 162, is in contact with the lower edge of the support opening 121 of the front support frame 120f. Thus, the leaf spring 160 acts as an electrical path connecting the rotation axis 32c of the photoreceptor 32 and the lower edge of the support opening 121. As a result, the charge stored in the photosensitive layer 32a of the photoreceptor 32 flows from the conductive substrate 32b through the rotation axis 32c, through the leaf spring 160 which is the positioning component 122, to the front support frame 120f, and is grounded. Thus, in this example, since the positioning component 122 also serves as the grounding component, it is possible to reduce the number of parts compared to a system in which the positioning component 122 and the grounding component are used separately.

[0043] -Removal of positioning parts- For example, when replacing the process cartridge 100, which is one of the imaging engines 30, it is necessary to remove the positioning component 122. In this case, the user should remove the outer cover 190 or the like, then lift the tip of the biasing portion 162 of the leaf spring 160, which is the positioning component 122, from the lower edge of the support opening 121, and pull out the leaf spring 160 diagonally upward.

[0044] ◎Embodiment 2 Figure 10(a) is a diagram illustrating the relationship between the front end of the process cartridge 100 and the support opening 121 of the front support frame 120f before the positioning component 122 is attached. In the figure, at the front end of the process cartridge 100, the protruding portion 132 of the protective cover 131 of the photoreceptor 32 is positioned facing the upper half of the support opening 121. Therefore, the peripheral edge corresponding to the upper half of the support opening 121 is hidden in the area where the protruding portion 132 of the protective cover 131 is located. However, the peripheral edge corresponding to the lower half of the support opening 121 is exposed from the outside of the front support frame 120f. This situation was found to persist even if, for example, a removable outer cover 190 were provided on the outer peripheral edge of the support opening 121 of the front support frame 120f to cover the edge of the support opening 121. When viewing the peripheral edge of the support opening 121 from near the center, the peripheral edge corresponding to the lower half of the support opening 121 remains exposed.

[0045] Therefore, in this embodiment, we focus on the fact that the positioning component 122 is attached to the protective cover 131 of the photoreceptor 32, as shown in Figure 10(b). Thus, the shape of the positioning component 122 has been partially modified from the shape of the first embodiment. In this example, the positioning component 122 is substantially the same as in Embodiment 1, with a mounting portion 161 and a biasing portion 162 attached to a leaf spring 160. In addition, a pair of wing-shaped covering portions 163 are integrally molded on both sides of the mounting portion 161 in the width direction, separated from the biasing portion 162 via a notch 164. The pair of covering portions 163 cover approximately two-thirds of the area of ​​the peripheral edges on both sides of the support opening 121, with the upper and lower portions partially removed. In this example, since a pair of covering portions 163 are integrally molded on both sides of the mounting portion 161, the shape eliminates the recess 141 that was formed in the protruding portion 132 of the protective cover 131 in Embodiment 1. Furthermore, as shown in Figure 11, the upper and lower portions of the peripheral edges on both sides of the support opening 121 that cannot be concealed by the covering portion 163 are covered separately with an outer cover 190, so that substantially the entire inner peripheral edge of the support opening 121 is covered by the covering portion 163 of the positioning component 122 and the outer cover 190.

[0046] Furthermore, in this embodiment, as shown in Figure 11, if the outer surface position of the front support frame 120f is P1, the outer surface position of the leaf spring 160 which is the positioning component 122 is P2, and the outer surface position of the outer cover 190 is P3, then they are arranged in the order P1 → P2 → P3 from the inside out. Therefore, the inner peripheral edge of the support opening 121 of the front support frame 120f is positioned inside the cover portion 163 of the positioning component 122 and the outer cover 190, so the inner peripheral edge of the support opening 121 is covered from the outside by the cover portion 163 and the outer cover 190, effectively concealing it. Furthermore, in this embodiment as well, the mounting portion 161 of the leaf spring 160, which is the positioning component 122, is secured to the protective cover 131 of the photoreceptor 32, and the tip of the biasing portion 162 of the leaf spring 160 is also secured to the outer cover 190. Therefore, in this example, the positioning component 122 cannot be removed unless the outer cover 190 is removed, due to the two securing structures at the top and bottom. Thus, accidental disassembly of the image engine 30 by the user is effectively prevented.

[0047] ◎Embodiment 3 Figure 12 is an explanatory diagram showing the mounting state of the positioning component according to Embodiment 3. In the figure, the positioning component 122 consists of an elastically deformable conductive leaf spring 160 and has a mounting portion 161 that is detachably attached to one end of the process cartridge 100, a biasing portion (first biasing portion) 162 which is integrally formed with the mounting portion 161 and provided in a part that ensures electrical contact between the conductive substrate 32b of the photoreceptor 32 and the front support frame 120f, and biases the process cartridge 100 in a direction intersecting the rotation axis 32c direction of the photoreceptor 32 (vertical direction in this example) so as to enable positioning by the positioning mechanism 150, and another biasing portion (second biasing portion) 165 which is integrally formed with the mounting portion 161 and separate from the biasing portion 162, and biases the process cartridge 100 in the direction of the rotation axis 32c of the photoreceptor 32.

[0048] In particular, in this example, it is preferable to integrally form the biasing portion 162 and another biasing portion 165 with respect to the mounting portion 161 by dividing them into two branches, making the biasing portion 162 bent into a U-shape in cross-section, and the other biasing portion 165 extending in a straight line, with the tip ends of the biasing portion 162 and the other biasing portion 165 in contact with the edge of the support opening 121 of the front support frame 120f. In this example, the positioning component 122 biases the front end of the process cartridge 100 with an elastic biasing force F1 in a direction intersecting the rotation axis 32c direction of the photoreceptor 32 (vertical direction in this example) by the biasing portion 162 of the leaf spring 160, and positions it using the positioning mechanism 150. Furthermore, another biasing portion 165 biases the front end of the process cartridge 100 with an elastic biasing force F2 in the direction of the rotation axis 32c direction of the photoreceptor 32 (direction toward the rear support frame 120r in this example), and positions it at an axial positioning location not shown. Furthermore, similar to Embodiment 1, the biasing portion 162 acts as an electrical circuit that connects the rotation axis 32c of the photoreceptor 32 and the front support frame 120f, and functions as a grounding component. Thus, in this example, the positioning component 122 positions the process cartridge 100 in two intersecting directions and also serves as a grounding component. [Examples]

[0049] ◎Example 1 This embodiment simplifies the shape of the positioning component according to Embodiment 1 and calculates the positioning biasing force relative to the front end of the process cartridge through simulation. In this example, the positioning component uses a leaf spring 160 made of SUS304 steel. As shown in Figures 13(a) and 13(b), the plate width w of the mounting portion 161 and the biasing portion 162 are the same (14 mm in this example), except for the upper hook portion 612 of the mounting portion 161. Furthermore, a leaf spring 160 with a plate thickness of 0.4 mm is used, and the shape and characteristic parameters of the leaf spring 160 are appropriately selected. Now, as shown in Figure 14, in selecting the characteristic value of the biasing portion 162 of the leaf spring 160, a. Dimension D between contact point 1 and 2 When the contact point C1 between the biasing unit 162 and the rotation axis 32c of the photoreceptor 32 is defined as contact point 1, and the contact point C2 between the biasing unit 162 and the lower edge of the support opening 121 is defined as contact point 2, this refers to the vertical distance between contact points 1 and 2. b. Spring length (X direction) This refers to the dimension in the X direction (corresponding to the rotation axis 32c direction of the photoreceptor 32) from the contact point 1 of the bent body portion 621 of the biasing portion 162 to the bending apex. c. Spring length (Y direction) This refers to the dimension in the Y direction (corresponding to the vertical direction) from contact point 1 to contact point 2 of the biasing section 162 before assembly (unloaded). d. Spring load length G after assembly This refers to the Y-direction dimension when a spring load is applied after assembly of the spring length (Y-direction). In this example, when the "distance between contact points 1 and 2" was set to 2 mm, the "spring length (X direction)" to 4.4 mm, the "spring length (Y direction)" to 7 mm, and the "spring load length after assembly" to 6.2 mm, the elastic biasing force F1 exceeded 30 N, which was found to be sufficient for positioning the process cartridge 100.

[0050] ◎Comparative Example 1 Comparative Example 1 involved a type of spring other than a leaf spring (e.g., a wire spring) that biased the process cartridge, and the extent of elastic biasing force that could be obtained was investigated. As shown in Figures 15(a) and 15(b), the rotation axis 32c of the photoreceptor 32 of the process cartridge 100 is biased by a wire spring S, and this wire spring S is grounded via a support frame 300. In this example, the wire spring S biases the process cartridge 100 and also serves as a grounding component. Here, when a wire spring S with a spring width of 4 mm and a wire diameter of 0.8 mm x 5 turns was used, the elastic biasing force F' (measured by contact pressure) due to the wire spring S was 5.8 N. In order to increase the spring force of a wire spring, it is necessary to increase the wire diameter or coil diameter. However, it was found that it is difficult to increase the wire diameter or number of coils of the wire spring due to constraints from other power supply paths (for example, the power supply path E1 to the developing roll of the developing unit, the power supply path E2 to the charging roll of the charging unit, and the waste toner transport path E3 of the cleaning unit). Therefore, in Comparative Example 1, it is difficult to secure a large elastic biasing force F' by the wire spring S, and thus the wire spring S cannot be used as a positioning component as is. Accordingly, in Comparative Example 1, for example, when assembling multiple process cartridges 100 using an assembly jig, the wire spring S is temporarily held on the support frame 300 side, the process cartridges 100 are lifted with the assembly jig and positioned and fastened to the support frame 300 with screws, and then the temporary holding of the wire spring S is released to secure contact with the rotation axis 32c of the photoreceptor 32. [Explanation of Symbols]

[0051] 1…Image holding means, 2…Image holder, 2a…Charge holding layer, 2b…Conductive substrate, 2c…Rotation axis, 3…Holding frame, 4…Support frame, 4a…Support opening, 5…Positioning means, 6…Positioning part, 7…Elastic member, 8…Mounting part, 9…Biasing part, 11…Support frame on the opposite side, 12…Positioning means on the opposite side, 13…Drive source, 14…Outer cover

Claims

1. An image holding means comprising an image holder detachably mounted to the device housing, having an image holder having a charge-holding layer on a conductive substrate, and a holding frame that rotatably holds the image holder, The image holding means includes a support frame provided at one end of the image holder in the rotation axis direction, which is made of a conductive material and has a support opening capable of supporting one end of the image holding means, A positioning means is provided on a part of the edge of the support opening of the support frame, and when the image holding means is mounted on the device housing, a part of the holding frame of the image holding means is positioned relative to the support frame, A positioning component comprising: a mounting portion made of an elastically deformable conductive elastic member, which is detachably attached to one end of the image holding means; and a biasing portion integrally formed with the mounting portion and provided in a portion that ensures electrical conductivity between the conductive base of the image holder and the support frame, which biases the image holding means in a direction intersecting the rotation axis direction of the image holder so as to enable positioning by the positioning means; An image forming apparatus characterized by comprising:

2. An image holding means comprising an image holder detachably mounted to the device housing, having an image holder having a charge-holding layer on a conductive substrate, and a holding frame that rotatably holds the image holder, The image holding means includes a support frame provided at one end of the image holder in the rotation axis direction, which is made of a conductive material and has a support opening capable of supporting one end of the image holding means, A positioning means is provided on a part of the edge of the support opening of the support frame, and when the image holding means is mounted on the device housing, a part of the holding frame of the image holding means is positioned relative to the support frame, A positioning component comprising: a mounting portion made of an elastically deformable conductive elastic member, which is detachably attached to one end of the image holding means; a biasing portion integrally formed with the mounting portion and provided in a portion that ensures electrical conductivity between the conductive base of the image holder and the support frame, which biases the image holding means in a direction intersecting the rotation axis direction of the image holder so as to enable positioning by the positioning means; and another biasing portion integrally formed with the mounting portion or the biasing portion, which biases the image holding means in the rotation axis direction of the image holder. An image forming apparatus characterized by comprising:

3. In the image forming apparatus according to claim 1 or 2, The image forming apparatus is characterized in that the positioning component is made of a leaf spring.

4. In the image forming apparatus according to claim 3, The image forming apparatus is characterized in that the positioning component is configured such that one side of the leaf spring is bent into a substantially U-shape in cross-section to form the mounting portion, and the other side is bent into a substantially U-shape in cross-section on the opposite side from the mounting portion to form the biasing portion.

5. In the image forming apparatus according to claim 1 or 2, The image forming apparatus is characterized in that the mounting portion embraces and holds a portion to be mounted that is pre-formed on one end of the image holding means.

6. In the image forming apparatus according to claim 5, The image forming apparatus is characterized in that the mounting portion has a structure that allows it to be positioned on a positioning portion that is pre-formed on the portion to be mounted.

7. In the image forming apparatus according to claim 5, The image forming apparatus is characterized in that the mounting portion has a retaining portion (retaining hole) related to a retaining portion that is pre-formed on the portion to be mounted.

8. In the image forming apparatus according to claim 5, The image forming apparatus is characterized in that the mounting portion is arranged in a manner that does not come into contact with the edge of the support opening of the support frame and the positioning means.

9. In the image forming apparatus according to claim 1 or 2, The biasing portion is characterized by contacting and compressing the biasing portion between a part of the conductive substrate of the image holder and the edge of the support opening of the support frame located on the opposite side of the positioning means, thereby biasing the image holder toward the positioning means.

10. In the image forming apparatus according to claim 9, The biasing portion is arranged such that the contact point on the image holding means side and the contact point on the support frame side coincide in the rotation axis direction of the image holder, characterized in that it is an image forming apparatus.

11. In the image forming apparatus according to claim 9, The image forming apparatus is characterized in that the biasing portion has an elastic biasing force greater than the elastic holding force of the mounting portion.

12. In the image forming apparatus according to claim 1 or 2, The image forming apparatus is characterized in that the positioning component is a leaf spring that can be added later.

13. In the image forming apparatus according to claim 12, The image forming apparatus is characterized in that the leaf spring has a covering portion that covers the edge of the support opening of the support frame.

14. In the image forming apparatus according to claim 12, An image forming apparatus characterized by having an outer cover on the outside of the support opening of the support frame that covers the tip of the leaf spring and the edge of the support opening from the outside.

15. In the image forming apparatus according to claim 2, The positioning component is made of a leaf spring that can be added later, and the biasing portion and the other biasing portion are integrally formed with respect to the mounting portion by dividing them into two branches, the biasing portion is bent into a U-shape in cross-section, and the other biasing portion is made to extend in a straight line, and the tip sides of the biasing portion and the other biasing portion are positioned in contact with the edge of the support opening of the support frame, characterized in that the image forming apparatus.

16. A positioning component used in an image forming apparatus, comprising: an image holding means having an image holder detachably mounted to the apparatus housing and having a charge-holding layer provided on a conductive substrate, and a holding frame that rotatably holds the image holder; a support frame provided at one end of the image holding means in the rotation axis direction of the image holder, made of a conductive material and having a support opening capable of supporting one end of the image holding means; and a positioning means provided at a part of the edge of the support opening of the support frame, for positioning a part of the holding frame of the image holding means relative to the support frame when the image holding means is mounted to the apparatus housing, wherein It consists of an elastic member that is elastically deformable and has conductivity, A mounting portion is detachably attached to a mounting portion that is pre-formed on one end of the image holding means, A biasing portion is integrally formed with the mounting portion and has a portion that contacts two locations: the conductive base of the image holder and the edge of the support opening of the support frame, and ensures electrical conductivity between the conductive base of the image holder and the support frame, and biases the image holder means in a direction intersecting the rotation axis direction of the image holder so that positioning by the positioning means is possible, A positioning component characterized by having the following features.

Images