Image forming apparatus and intermediate transfer unit

Abstract

To provide an image forming apparatus comprising a belt cleaning device that is removably mounted on a frame unit of an intermediate transfer unit, and to acquire information on the history of use of the frame unit even when the belt cleaning device is replaced.SOLUTION: An image forming apparatus 100 has an image forming section S and an intermediate transfer unit 150. The intermediate transfer unit 150 is configured to be removably mounted on an apparatus body 120 of the image forming apparatus 100 with a cleaning unit 160 attached to a frame unit 200. The intermediate transfer unit 150 has a memory substrate 5 that is provided on the frame unit 200 and includes a storage section 5b storing information.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus such as a copying machine, printer, or facsimile machine using an electrophotographic or electrostatic recording method, or a multifunction machine having two or more of these functions, and to an intermediate transfer unit used in this image forming apparatus. [Background technology]

[0002] Conventionally, some image forming apparatuses, such as electrophotographic copying machines, employ an intermediate transfer method in which a toner image formed on an image carrier is primarily transferred to an intermediate transfer member, and then the toner image is secondarily transferred to a recording material such as paper. An intermediate transfer belt, which is an endless belt stretched over multiple tension rollers, is often used as the intermediate transfer member. Furthermore, in image forming apparatuses employing the intermediate transfer method, a belt cleaning device equipped with a cleaning member is used to remove any toner or other adhering matter remaining on the intermediate transfer belt after the toner image is secondarily transferred from the intermediate transfer belt to the recording material.

[0003] In such an image forming apparatus, an intermediate transfer unit including the intermediate transfer belt and the belt cleaning device may be made detachable from the main body of the image forming apparatus for maintenance of the intermediate transfer belt and the belt cleaning device.

[0004] A configuration has been proposed in which a memory board is provided in the belt cleaning device, and the image forming apparatus main body determines whether the belt cleaning device is new or old based on information stored in the memory (Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2022-48958 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, by collecting used intermediate transfer units from the market and reusing reusable parts, it is possible to provide an image forming apparatus and intermediate transfer unit that are environmentally friendly.

[0007] However, in some intermediate transfer units, the belt cleaning device is detachable from the frame unit equipped with the intermediate transfer belt. This is because the belt cleaning device can be replaced separately if the lifespan of the belt cleaning device is shorter than that of the frame unit, or if the belt cleaning device becomes difficult to remove toner from the intermediate transfer belt. In such a configuration, if a memory board is attached to the belt cleaning device, the usage history of the frame unit becomes obscured when the belt cleaning device is replaced. The frame unit has more components than the belt cleaning device, and reusing these components is advantageous in terms of reducing environmental impact.

[0008] Therefore, the object of the present invention is to make it possible to obtain information regarding the usage history of the frame unit even when the belt cleaning device is replaced in a configuration in which the belt cleaning device is detachable from the frame unit of the intermediate transfer unit.

[0009] Another object of the present invention is to simplify the configuration of the connection between the memory board on the intermediate transfer unit side and the contact member on the main body side of the image forming apparatus. [Means for solving the problem]

[0010] The above object is achieved by an image forming apparatus and an intermediate transfer unit according to the present invention. In summary, according to one aspect of the present invention, there is provided an image forming apparatus comprising: an image forming section that forms a toner image on an image carrier; an intermediate transfer unit to which the toner image formed on the image carrier is transferred and which transfers the transferred toner image onto a recording material, the intermediate transfer unit including: an intermediate transfer belt onto which the toner image is transferred from the image carrier; a plurality of tension rollers that suspend the intermediate transfer belt; and a frame unit having a frame that supports the plurality of tension rollers, and a cleaning unit that is detachable from the frame unit and removes toner from the surface of the intermediate transfer belt, wherein the intermediate transfer unit is configured to be detachable from a main body of the image forming apparatus with the cleaning unit attached to the frame unit, and the intermediate transfer unit is provided in the frame unit and includes a memory board that is provided with a memory unit that stores information.

[0011] According to another aspect of the present invention, there is provided an image forming apparatus comprising: an image forming section that forms a toner image on an image carrier; and an intermediate transfer unit that is detachable from the main body of the image forming apparatus and to which the toner image formed on the image carrier is transferred and which transfers the transferred toner image onto a recording material, wherein the intermediate transfer unit comprises an intermediate transfer belt to which the toner image is transferred from the image carrier; a plurality of tension rollers that tension the intermediate transfer belt; a frame that supports the plurality of tension rollers; and a memory board provided on the frame so as to be positioned outside the intermediate transfer belt in a belt width direction that intersects the direction of movement of the intermediate transfer belt, the memory board having a memory section that stores information and a connection section that can be connected to a contact member provided on the main body of the apparatus.

[0012] According to another aspect of the present invention, there is provided the intermediate transfer unit used in the image forming apparatus of the present invention. [Effects of the Invention]

[0013] According to the present invention, in a configuration in which the belt cleaning device is detachable from the frame unit of the intermediate transfer unit, even if the belt cleaning device is replaced, it is possible to obtain information regarding the usage history of the frame unit.

[0014] In addition, according to the present invention, by providing the memory board on the side of the intermediate transfer unit, it is possible to simplify the configuration of the connection portion between the memory board on the intermediate transfer unit side and the contact member on the main body side of the image forming apparatus. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic cross-sectional view of an image forming apparatus. [Figure 2] FIG. 2 is a schematic perspective view of an intermediate transfer unit. [Figure 3] FIG. 2 is an enlarged perspective view of the vicinity of a tension roller of the intermediate transfer unit. [Figure 4] 2 is a schematic cross-sectional view of the image forming apparatus showing how the intermediate transfer unit is attached to and detached from the apparatus main body. FIG. [Figure 5] FIG. 2 is a schematic perspective view of the intermediate transfer unit, showing a state in which the belt cleaning device is detached from the frame unit. [Figure 6] FIG. 2 is a schematic block diagram illustrating a control configuration of the image forming apparatus. [Figure 7] FIG. 2 is a schematic diagram of the vicinity of the intermediate transfer unit as viewed from above. [Figure 8] FIG. [Figure 9] 5A and 5B are schematic diagrams for explaining the tendency of fluctuation in the position of the intermediate transfer unit. [Figure 10] FIG. 4 is an exploded perspective view of the intermediate transfer unit for explaining the assembly of the intermediate transfer belt to the frame. [Figure 11] FIG. 10 is a schematic diagram of the vicinity of an intermediate transfer unit in another example, as viewed from above. [Figure 12] FIG. 10 is a schematic diagram of the vicinity of an intermediate transfer unit in another example, as viewed from above. [Figure 13]FIG. 10 is a schematic perspective view of an intermediate transfer unit according to another example. [Figure 14] FIG. 10 is a schematic perspective view of an intermediate transfer unit according to another example. [Figure 15] FIG. 10 is a schematic perspective view of an intermediate transfer unit according to another example. DETAILED DESCRIPTION OF THE INVENTION

[0016] The image forming apparatus and intermediate transfer unit according to the present invention will be described in more detail below with reference to the drawings.

[0017] [Example 1] 1. Overall configuration and operation of the image forming apparatus 1 is a schematic cross-sectional view of an image forming apparatus 100 according to this embodiment. The image forming apparatus 100 according to this embodiment is a tandem-type full-color printer that employs an intermediate transfer method and is capable of forming full-color images using an electrophotographic method. The image forming apparatus 100 can form an image on a sheet-like recording material P, such as paper, in response to an image signal (image information) sent from an external device, such as a personal computer.

[0018] Here, with respect to the image forming apparatus 100 and its elements, the front side of the paper in FIG. 1 when the image forming apparatus 100 is operating will be referred to as the "front side (front face side)," and the back side of the paper in FIG. 1 will be referred to as the "rear side (back face side)." The front-to-rear direction (the direction perpendicular to the paper in FIG. 1) connecting the front side and the rear side will be approximately parallel to the rotation axis directions of the photosensitive drum 101 and tension rollers 201-204 of the intermediate transfer belt 1, which will be described later, when the image forming apparatus 100 is operating. Furthermore, with respect to the image forming apparatus 100 and its elements, the left side when viewed from the front side will be referred to as the "left side," and the right side will be referred to as the "right side." Furthermore, with respect to the image forming apparatus 100 and its elements, the terms "up" and "down" refer to the up and down in the direction of gravity (vertical direction), but do not mean only directly above and directly below, respectively, and also include the upper and lower sides of a horizontal plane passing through the element or position of interest.

[0019] The image forming apparatus 100 has four image forming units SY, SM, SC, and SK that form toner images of yellow (Y), magenta (M), cyan (C), and black (K), respectively. Elements having the same or corresponding functions or configurations for each color may be generally described by omitting the Y, M, C, or K suffix to the reference numeral indicating the element for that color. In this embodiment, the image forming unit S includes a photosensitive drum 101, a charging roller 102, an exposure device 103, a developing device 104, a drum cleaning device 105, and other components, which will be described later. In this embodiment, the exposure device 103 is configured as a single unit that exposes the photosensitive drum 101 of each image forming unit S, but may be provided independently for each image forming unit S.

[0020] The photosensitive drum 101, a drum-type (cylindrical) photosensitive member (electrophotographic photosensitive member) serving as an image carrier, is rotated in the direction of arrow R1 (clockwise) in the figure at a predetermined peripheral speed (process speed). The surface (outer periphery) of the rotating photosensitive drum 101 is uniformly charged to a predetermined potential of a predetermined polarity (negative in this embodiment) by a charging roller 102, a roller-type charging member serving as charging means. The charged surface of the photosensitive drum 102 is scanned and exposed by an exposure device (laser scanner) 103 serving as exposure means in accordance with an image signal, and an electrostatic latent image (electrostatic image) is formed on the photosensitive drum 101. The electrostatic latent image formed on the photosensitive drum 101 is developed (visualized) by a developing device 104 serving as developing means, which supplies toner as a developer, and a toner image is formed on the photosensitive drum 101. In this embodiment, toner charged with the same polarity (negative in this embodiment) as the charge polarity of the photosensitive drum 101 adheres to the exposed portion (image portion) on the photosensitive drum 101, which has been uniformly charged and then exposed to light to reduce the absolute value of the potential (reverse development method). In this embodiment, the normal charge polarity of the toner, which is the main charge polarity of the toner during development, is negative.

[0021] An intermediate transfer belt 1, which is an endless belt serving as an intermediate transfer body, is disposed facing the four photosensitive drums 101Y, 101M, 101C, and 101K. The intermediate transfer belt 1 is stretched over and tensioned by a predetermined tension around a plurality of tension rollers, namely, a drive roller 201, a tension roller 202, a first auxiliary roller 203, and a second auxiliary roller 204. The intermediate transfer belt 1 is driven by input of a driving force to the drive roller 201, and rotates (circularly moves) in the direction of arrow R2 (counterclockwise) in the figure at a peripheral speed (process speed) substantially the same as the peripheral speed of the photosensitive drums 101. The tension roller 202 applies a predetermined tension to the intermediate transfer belt 1. The first and second auxiliary rollers 203 and 204 form a substantially flat primary transfer surface on the intermediate transfer belt 1 onto which a toner image is primarily transferred from each photosensitive drum 1. The number of rollers around which the intermediate transfer belt 1 is tensioned is not limited to four. Primary transfer rollers 106Y, 106M, 106C, and 106K, which are roller-type primary transfer members serving as primary transfer means, are arranged on the inner circumferential surface of the intermediate transfer belt 1, corresponding to the photosensitive drums 101Y, 101M, 101C, and 101K, respectively. The primary transfer rollers 106 press the inner circumferential surface of the intermediate transfer belt 1 against the photosensitive drums 101. This forms a primary transfer portion (primary transfer nip portion) T1, which is a contact portion between the photosensitive drums 101 and the intermediate transfer belt 1. The tension rollers other than the drive roller 201 among the multiple tension rollers, and the primary transfer rollers 106, are rotated in accordance with the rotation of the intermediate transfer belt 1.

[0022] The toner image formed on the photosensitive drum 101 is transferred (primary transfer) onto the rotating intermediate transfer belt 1 by applying a predetermined pressure and electrostatic load bias at the primary transfer unit T1. During primary transfer, a primary transfer voltage (primary transfer bias), which is a DC voltage of opposite polarity (positive polarity in this embodiment) to the normal charging polarity of the toner, is applied to the primary transfer roller 106 by a primary transfer power supply (not shown). For example, when forming a full-color image, toner images of yellow, magenta, cyan, and black formed on each photosensitive drum 101 are sequentially transferred onto the intermediate transfer belt 1 so as to be superimposed on each other. The image formation process for each color, which is processed in parallel by each image forming unit S, is performed when a toner image primarily transferred downstream is superimposed on a toner image primarily transferred upstream onto the intermediate transfer belt 1. Note that the number of image forming units S is not limited to four colors, and the arrangement order of the image forming units S for each color is not limited to the order in this embodiment.

[0023] On the outer peripheral surface of the intermediate transfer belt 1, a secondary transfer outer roller (secondary transfer roller) 107, which is a roller-type secondary transfer member serving as a secondary transfer means, is disposed at a position facing the drive roller 201. The drive roller 201 also functions as a secondary transfer inner roller (opposing roller) serving as an opposing member. The secondary transfer outer roller 107 is pressed toward the drive roller 201 and applies an external force to the drive roller 201 via the intermediate transfer belt 1. This forms a secondary transfer portion (secondary transfer nip portion) T2, which is a contact portion between the intermediate transfer belt 1 and the secondary transfer outer roller 107. In this embodiment, the secondary transfer outer roller 107 is rotated in accordance with the rotation of the intermediate transfer belt 1. Note that the image forming apparatus 100 may be configured such that the secondary transfer outer roller 107 is driven to rotate. The toner image formed on the intermediate transfer belt 1 is transferred (secondary transfer) onto the recording material P, which is being sandwiched and conveyed between the intermediate transfer belt 1 and the outer secondary transfer roller 107, by applying a predetermined pressure and an electrostatic load bias at the secondary transfer portion T2. ​​During secondary transfer, a secondary transfer voltage (secondary transfer bias), which is a DC voltage of opposite polarity (positive polarity in this embodiment) to the normal charging polarity of the toner, is applied to the outer secondary transfer roller 107 by a secondary transfer power source (not shown). The drive roller 201 is electrically grounded. Alternatively, the secondary transfer voltage may be applied to an inner secondary transfer roller serving as a secondary transfer member corresponding to the drive roller 201 in this embodiment, and the outer secondary transfer roller serving as an opposing member corresponding to the outer secondary transfer roller 107 in this embodiment may be electrically grounded. In this case, during secondary transfer, a secondary transfer voltage of the same polarity as the normal charging polarity of the toner is applied to the inner secondary transfer roller.

[0024] Recording materials (sheets, transfer materials, recording media) P are stacked and stored in a recording material cassette 108 serving as a recording material storage unit. The recording materials P stored in the recording material cassette 108 are fed out one by one from the recording material cassette 108 by a feed roller 109 or other feeding member serving as a feeding means. The recording material P fed out of the recording material cassette 108 is conveyed through a conveying path 111 by a conveying roller pair 110 or other conveying member serving as a conveying means to a registration roller pair 112 which is a conveying member serving as a conveying means. After skew correction is performed on this recording material P by the registration roller pair 112, the timing is matched with the toner image on the intermediate transfer belt 1 and the recording material P is sent to the secondary transfer unit T2.

[0025] The recording material P onto which the toner image has been transferred is transported to a fixing device 113 serving as a fixing means. The fixing device 113 uses a fixing roller 113a equipped with a heat source and a pressure roller 113b that is in pressure contact with the fixing roller 113a to apply pressure and heat to the recording material P carrying the unfixed toner image while transporting it, thereby fixing (melting and fixing) the toner image to the recording material P. The recording material P onto which the toner image has been fixed is discharged (output) onto a discharge tray 115 provided outside the apparatus main body 120 of the image forming apparatus 100 by a pair of discharge rollers 114 or the like.

[0026] Meanwhile, the toner remaining on the photosensitive drum 101 after the primary transfer process (primary transfer residual toner) is removed from the photosensitive drum 101 and collected by a drum cleaning device 105 serving as a photosensitive body cleaning means. Also, the toner remaining on the intermediate transfer belt 1 after the secondary transfer process (secondary transfer residual toner) and adhering materials such as paper dust are removed from the intermediate transfer belt 1 and collected by a belt cleaning device 160 serving as an intermediate transfer body cleaning means. The collected materials such as the toner and paper dust collected by the drum cleaning device 105 and the belt cleaning device 160 are transported to a waste toner container (not shown) disposed in the device main body 120 via a waste toner transport path (not shown) provided in the device main body 120.

[0027] In this embodiment, in each image forming station S, the photosensitive drum 101, the charging roller 102, the developing device 104, and the drum cleaning device 105 integrally constitute a process cartridge 130 that is detachably mountable to the apparatus main body 120.

[0028] In this embodiment, the intermediate transfer belt 1, the plurality of tension rollers 201 to 204, the primary transfer rollers 106, and the belt cleaning device 160 integrally constitute an intermediate transfer unit 150 that is detachable from the apparatus main body 120. The intermediate transfer unit 150 will be described in further detail later.

[0029] In this embodiment, the apparatus main body 120 of the image forming apparatus 100 corresponds to the parts of the image forming apparatus 100 other than the process cartridges 10 and the intermediate transfer unit 150 .

[0030] In this embodiment, the intermediate transfer unit 150 is detachably disposed at a vertically central position within the device body 120. When the intermediate transfer unit 150 is attached to the device body 120, it is supported by front rails 10F and rear rails 10R (FIGS. 4 and 7), which are rail-shaped attachment portions provided on a frame on both ends of the intermediate transfer belt 1 in the width direction within the device body 120. The width direction (belt width direction) of the intermediate transfer belt 1 is substantially perpendicular to the direction of movement of the surface of the intermediate transfer belt 1 and substantially parallel to the rotation axis direction of the multiple tension rollers 201-204. When the intermediate transfer unit 150 is attached to the device body 120, the belt cleaning device 160 provided in the intermediate transfer unit 150 is connected to a waste toner transport path (not shown) provided within the device body 120. The attachment and detachment of the intermediate transfer unit 150 to and from the device body 120 will be described in more detail later. In this embodiment, four process cartridges 130Y, 130M, 130C, and 130K are arranged below the intermediate transfer unit 150 from upstream to downstream along the direction of movement of the primary transfer surface of the intermediate transfer belt 1. In this embodiment, the arrangement direction of the four image forming units S (photosensitive drums 101) is approximately horizontal. In other words, in this embodiment, the common tangent plane of the four photosensitive drums 101 on the sides that come into contact with the intermediate transfer belt 1 is approximately horizontal.

[0031] 2. Intermediate transfer unit Next, the intermediate transfer unit 150 in this embodiment will be further described with reference to Figures 1 to 3. Figure 2 is a schematic perspective view of the intermediate transfer unit 150 in this embodiment. Figure 3 is a schematic perspective view showing an enlarged view of the vicinity of the tension roller 202 of the intermediate transfer unit 150 in this embodiment.

[0032] The image forming apparatus 100 has an intermediate transfer unit 150 as a belt conveying device disposed to face four photosensitive drums 101Y, 101M, 101C, and 101K. The intermediate transfer unit 150 has a frame 206, multiple tension rollers 201 to 204, primary transfer rollers 106Y, 106M, 106C, and 106K, an intermediate transfer belt 1, and a belt cleaning device (cleaning unit) 160. In this embodiment, the intermediate transfer unit 150 has multiple tension rollers, including a drive roller 201, a tension roller 202, and first and second auxiliary rollers 203 and 204. The frame 206 is a frame body for supporting the multiple tension rollers 201 to 204 and the primary transfer rollers 106Y, 106M, 106C, and 106K. The multiple tension rollers 201-204 and primary transfer rollers 106Y, 106M, 106C, and 106K are rotatably held by a frame 206. The rotation axes of the multiple tension rollers 201-204 and primary transfer rollers 106Y, 106M, 106C, and 106K are substantially parallel to one another. The intermediate transfer belt 1 is stretched over the tension rollers 201-204. The intermediate transfer unit 150 is configured by assembling each of these elements together. The intermediate transfer unit 150, which serves as a replaceable unit, is configured to be removable (attachable and detachable) as a unit with respect to the device main body 120.

[0033] The drive roller 201 forms a secondary transfer portion T2 by sandwiching the intermediate transfer belt 1 between itself and the outer secondary transfer roller 107. The drive roller 201 also functions as an inner secondary transfer roller that faces the outer secondary transfer roller 107 with the intermediate transfer belt 1 interposed therebetween.

[0034] The first and second auxiliary rollers 203 and 204 form a primary transfer surface onto which the toner image on the intermediate transfer belt 1 is primarily transferred. The second auxiliary roller 204 has a crown shape in which the outer diameter is greatest at approximately the center in the direction of its rotation axis and gradually decreases toward both ends. This is to prevent the tension of the intermediate transfer belt 1 from bending the center in the direction of the rotation axis of the second auxiliary roller 204 and causing wrinkles in the center of the intermediate transfer belt 1 in the width direction.

[0035] The tension roller 202 is rotatably supported by bearing members 205 (FIG. 3) at both ends in the direction of its rotation axis. The bearing members 205 are attached to a frame 206 so as to be movable (slidable). The bearing members 205 at both ends of the tension roller 202 are biased (pressurized) from the inner circumferential surface side toward the outer circumferential surface side of the intermediate transfer belt 1 by the biasing force (pressure force, compression force) of tension springs 207, which are biasing members serving as biasing means and are made of compression springs. The bearing members 205 are then moved (slid) from the inner circumferential surface side toward the outer circumferential surface side of the intermediate transfer belt 1 along the biasing direction of the tension springs 207. As a result, the tension roller 202 biases the intermediate transfer belt 1 from the inner circumferential surface side toward the outer circumferential surface side of the intermediate transfer belt 1, thereby applying tension to the intermediate transfer belt 1.

[0036] In addition, regulating collars 208 are provided at both ends of the tension roller 202 in the rotational axis direction as regulating members for regulating the shift of the intermediate transfer belt 1 ( FIG. 3 ). The shift of the intermediate transfer belt 1 refers to the phenomenon in which the intermediate transfer belt 1 moves in the width direction while rotating. Ribs 2 are provided on the inner circumferential surface of both ends of the intermediate transfer belt 1 in the width direction, protruding from the inner circumferential surface as regulated members ( FIG. 3 ). In this embodiment, the rib 2 has a substantially rectangular cross section substantially perpendicular to its extension direction, and is fixed to the inner circumferential surface of the intermediate transfer belt 1 by adhesive. In this embodiment, the rib 6 is provided along substantially the entire circumference of the intermediate transfer belt 1, and both ends of the rib 2 in the extension direction face each other. The shift of the intermediate transfer belt 1 is regulated by the abutment of the rib 2 and the regulating collars 208. In this embodiment, reinforcing tape (reinforcing member) 3 is provided on the outer circumferential surface of both ends of the intermediate transfer belt 1 in the width direction ( FIG. 3 ). In this embodiment, the reinforcing tape 3 is fixed by adhesion to the outer circumferential surface of the intermediate transfer belt 1. In this embodiment, the reinforcing tape 3 is provided over substantially the entire circumference of the intermediate transfer belt 1.

[0037] In this embodiment, the intermediate transfer belt 1 is made of a resin belt having a base layer of polyimide (PI). In this embodiment, the intermediate transfer belt 1 has a tensile elastic modulus E of 18000 N / cm 2 and a thickness of 0.08 mm. The intermediate transfer belt 2 is preferably made of a resin with relatively high rigidity, such as polyvinylidene fluoride (PVDF), polyamide, polyimide resin (PI), polyethylene terephthalate (PET), or polycarbonate (PC). The thickness of the intermediate transfer belt 1 is preferably in the range of 0.02 mm to 0.50 mm. If the intermediate transfer belt 1 is too thin, it may not be durable enough due to wear, while if it is too thick, it may be difficult to bend on the drive roller 201, tension roller 202, and first and second auxiliary rollers 203 and 204, resulting in deformation or creases.

[0038] The belt cleaning device 160 includes a cleaning blade 161 as a cleaning member, a conveying screw 162 as a conveying member, and a cleaning container 163 as a housing (FIG. 1). The cleaning blade 161 is a plate-like member made of an elastic material, having a predetermined length in both a longitudinal direction (which is approximately parallel to a direction substantially perpendicular to the moving direction of the surface of the intermediate transfer belt 1) and a lateral direction (which is approximately perpendicular to the longitudinal direction) and a predetermined thickness. The cleaning blade 161 is disposed opposite the tension roller 202 across the intermediate transfer belt 1 at an angle counter to the moving direction of the surface of the intermediate transfer belt 1. In other words, the cleaning blade 161 is disposed so that its free end in the lateral direction faces upstream in the moving direction of the surface of the intermediate transfer belt 1. The edge of the free end of the cleaning blade 161 in the lateral direction is brought into contact with the surface of the intermediate transfer belt 1, applying an external force to the tension roller 202 via the intermediate transfer belt 1. The cleaning blade 161 has a fixed end in the short direction thereof adhered to a supporting metal plate (not shown) serving as a supporting member, and the supporting metal plate is fixed to the cleaning container 163 with screws or the like, thereby supporting the cleaning blade 161 in the cleaning container 163.

[0039] The collected matter, such as toner collected from the intermediate transfer belt 1 by the cleaning blade 161, is stored in a collected toner storage section 163a formed in the cleaning container 163. A conveying screw 162 is disposed in the collected toner storage section 163a. ​​The conveying screw 162 conveys the collected matter, such as toner, in the collected toner storage section 163a along the longitudinal direction of the belt cleaning device 160 (cleaning blade 161) toward one end (e.g., the front end) of the cleaning container 163. The collected matter, such as toner, conveyed by the conveying screw 162 is discharged from an outlet (not shown) provided at the one end of the cleaning container 163 and sent to a waste toner conveying path (not shown) provided in the device main body 120. The collected matter sent to the waste toner conveying path is conveyed to a waste toner container (not shown) detachably attached to the device main body 120. The waste toner container is replaced when it becomes full.

[0040] The belt cleaning device 160 rubs a cleaning blade 161 against the surface of the intermediate transfer belt 1 to remove and collect adhering matter, such as residual toner after secondary transfer, from the surface of the intermediate transfer belt 1. The cleaning blade 161 is in contact with the area where the intermediate transfer belt 1 is wound around the tension roller 202. As described above, the tip of the cleaning blade 161 faces in the counter direction relative to the moving direction of the surface of the intermediate transfer belt 1. The belt cleaning device 160 brings the tip of the cleaning blade 161 into contact with the surface (outer peripheral surface) of the intermediate transfer belt 1 to collect adhering matter, such as residual toner after secondary transfer. In this embodiment, the cleaning blade 161 is made of urethane rubber. This urethane rubber has a JIS-A hardness of 75 degrees and a thickness of 2 mm. In this embodiment, the cleaning blade 161 has a contact angle of 25° and a contact pressure of 3 N / m (30 gf / cm). However, the configuration of the belt cleaning device 160 is not limited to this.

[0041] The primary transfer roller 106 is pressed (biased) against the inner circumferential surface of the intermediate transfer belt 1 by a pressure mechanism (not shown). As a result, the primary transfer roller 106 presses the intermediate transfer belt 1 toward the photosensitive drum 101, forming a primary transfer portion T1. The intermediate transfer unit 150 has bearing members (not shown) that rotatably support the primary transfer rollers 106Y, 106M, 106C, and 106K and the first and second auxiliary rollers 203 and 204. These bearing members are configured to allow each roller to move toward and away from a common tangent plane on the side of the four photosensitive drums 101Y, 101M, 101C, and 101K that contacts the intermediate transfer belt 1. The intermediate transfer unit 150 also has a movement mechanism (contact / separation mechanism) (not shown) that moves these bearing members.

[0042] In this embodiment, the tension state of the intermediate transfer belt 1 can be changed to the following first, second, and third tension states by the movement mechanism. In the first tension state, all of the primary transfer rollers 106Y, 106M, 106C, and 106K and the first and second auxiliary rollers 203 and 204 are positioned at second positions (separate positions) away from the tangent plane. As a result, the intermediate transfer belt 1 is spaced apart from all of the photosensitive drums 101Y, 101M, 101C, and 101K. In the second tension state, all of the primary transfer rollers 106Y, 106M, 106C, and 106K and the first and second auxiliary rollers 203 and 204 are positioned at first positions (contact positions) closer to the tangent plane than the second positions (separate positions). As a result, the intermediate transfer belt 1 contacts all of the photosensitive drums 101Y, 101M, 101C, and 101K. In the third tension state, the primary transfer rollers 106Y, 106M, and 106C for yellow, magenta, and cyan, and the first auxiliary roller 203 are disposed at the second position (separated position). Meanwhile, the primary transfer roller 106K and the second auxiliary roller 204 for black are disposed at the first position (contact position). As a result, the intermediate transfer belt 1 contacts only the black photosensitive drum 101K among the four photosensitive drums 101Y, 101M, 101C, and 101K. For example, the first tension state is used during standby for printing or when the intermediate transfer unit 150 is attached to or detached from the device main body 120. For example, the second tension state is used during color image printing. For example, the third tension state is used during monochrome image printing (black monochromatic image printing).

[0043] In this embodiment, the intermediate transfer unit 150 is provided with a memory board 5 as a storage device. The memory board 5 provided in the intermediate transfer unit 150 will be described later.

[0044] 3.Replacing the Intermediate Transfer Unit The intermediate transfer unit 150 is detachably attached to the apparatus main body 120 of the image forming apparatus 100. In this embodiment, the intermediate transfer unit 150 is configured to include a belt cleaning device 160 and a frame unit 200, which is another component of the intermediate transfer unit 150 and includes the intermediate transfer belt 1. In this embodiment, the frame unit 200 is configured to include a frame 206, a plurality of tension rollers 201 to 204, the intermediate transfer belt 1, and each primary transfer roller 106. The intermediate transfer unit 150 is detachably attached to the apparatus main body 120 with the belt cleaning device 160 attached to the frame unit 200. FIG. 4 is a schematic cross-sectional view of the image forming apparatus 100 of this embodiment, showing how the intermediate transfer unit 150 is attached to and detached from the apparatus main body 120.

[0045] As shown in FIG. 4, the image forming apparatus 100 has a right door unit 140 on its right side as an opening / closing member that opens the inside of the apparatus main body 120. The right door unit 140 is configured to rotate around a rotation shaft 140a provided at its bottom and extending in the front-to-rear direction. The right door unit 140 is opened by rotating its upper portion downward (in the direction of arrow A1 in FIG. 4) and closed by rotating its upper portion upward (in the direction of arrow A2, which is the opposite direction to arrow A1 in FIG. 4). The right door unit 140 is opened and closed by an operator, such as a user or a service technician, operating a handle provided on the right door unit 140. The right door unit 140 opens at least a portion of the transport path of the recording material P from the recording material cassette 108 through the secondary transfer unit T2 to the fixing device 113, dividing the recording material P into a front side (the side onto which a toner image is transferred) and a back side. The outer secondary transfer roller 107 is attached to the right door unit 140 side.

[0046] When the right door unit 140 is opened, the right door unit 140 is opened so that the outer secondary transfer roller 107 is separated from the intermediate transfer belt 1. When the right door unit 140 is opened, an operator can access the intermediate transfer unit 150 mounted in the apparatus main body 120. Then, by operating a handle or the like provided on the frame 206, the operator can pull the intermediate transfer unit 150 to the right (in the direction of arrow B1 in FIG. 4) and remove it from the apparatus main body 120. Conversely, the operator can insert the intermediate transfer unit 150 to the left (in the direction of arrow B2, which is the opposite direction to the direction of arrow B1 in FIG. 4) to mount it in the apparatus main body 120. The intermediate transfer unit 150 is supported and moved by front rails 10F and rear rails 10R, which are rail-shaped mounting portions provided on a frame within the apparatus main body 120. The intermediate transfer unit 150 is positioned and mounted in a predetermined position (mounting position) on the front rails 10F and rear rails 10R (FIG. 1). In this embodiment, the intermediate transfer unit 150 is moved in a substantially horizontal direction and is attached to and detached from the apparatus main body 120 (inserted and removed).

[0047] In this embodiment, the lifespan of the intermediate transfer belt 1 is shorter than the lifespan of the apparatus main body 120. Therefore, by making the intermediate transfer unit 150 detachable from the apparatus main body 120, the intermediate transfer belt 1 can be replaced with a new one. Note that the intermediate transfer belt 1 may be replaced by replacing only the intermediate transfer belt 1 with respect to the frame unit 200, or the entire frame unit 200 or the entire intermediate transfer unit 150 may be replaced.

[0048] Furthermore, if the lifespan of the belt cleaning device 160 is shorter than that of the frame unit 200, or depending on the method of use in the market, the belt cleaning device 160 may have difficulty removing toner from the intermediate transfer belt 1. In such cases, by replacing only the belt cleaning device 160 rather than replacing the intermediate transfer unit 150, it is possible to replace only the necessary parts. For this reason, in this embodiment, the belt cleaning device 160 is detachable from the frame unit 200 of the intermediate transfer unit 150, so that the belt cleaning device 160 can be replaced with a new one. FIG. 5 is a schematic perspective view of the intermediate transfer unit 150 in this embodiment, showing the belt cleaning device 160 removed from the frame unit 200. As such, in this embodiment, the belt cleaning device 160 is further detachable from the frame unit 200 in the intermediate transfer unit 150. This allows only the minimum necessary components to be replaced, thereby suppressing increases in the running costs of the image forming apparatus 100.

[0049] Furthermore, in this embodiment, if only the belt cleaning device 160 is replaced, rather than replacing the entire intermediate transfer unit 150, the user may be able to input this information through the operation unit 60 ( FIG. 6 ) provided on the apparatus main body 120 of the image forming apparatus 100. That is, if only the belt cleaning device 160 is replaced, the user can manually input information that the belt cleaning device 160 has been replaced through the operation unit 60. The control unit 50 may be configured to perform a predetermined initialization operation before starting image formation when it detects, based on an input signal from the operation unit 60, that only the belt cleaning device 160 has been replaced. This initialization operation may, for example, supply a toner strip as a lubricant to the contact portion between the cleaning blade 161 of the belt cleaning device 160 and the intermediate transfer belt 1. Furthermore, when the intermediate transfer unit 150 is replaced as a whole, the control unit 50 may be configured to detect that the intermediate transfer unit 150 is new based on the information stored in the memory board 5 and then perform the initialization operation. In this way, the image forming apparatus 100 can be configured to have an operation unit 60 provided in the apparatus main body 120, which allows the user to manually input that the belt cleaning device 160 has been replaced, and a control unit 50 configured to execute a predetermined initialization operation when the fact that the belt cleaning device 160 has been replaced is input from the operation unit 60.

[0050] 4.Storage device Next, a description will be given of the memory board 5 as a storage device provided in the intermediate transfer unit 150 in this embodiment. The memory board 5 has a memory contact 5a as a contact portion and a memory 5b as a storage portion (FIG. 6).

[0051] In this embodiment, destination information for the intermediate transfer unit 150 is recorded on the memory board 5. The "destination information" is, for example, information for detecting (determining) which image forming apparatus 100 the intermediate transfer unit 150 equipped with the memory board 5 is compatible with. The destination information is identification information that makes it possible to determine whether the intermediate transfer unit 150 is compatible with the apparatus main body 120. For example, intermediate transfer units 150 with different configurations may be installable in the same apparatus main body 120. As an example, an intermediate transfer unit 150 having multiple primary transfer rollers 106 (e.g., primary transfer rollers 106Y, 106M, 106C, and 106K for yellow, magenta, cyan, and black) and capable of transferring multi-color toner images, and an intermediate transfer unit 150 having only a single primary transfer roller 106 and not capable of transferring multi-color toner images, may be installable in the apparatus main body 120 of the same image forming apparatus 100. In this case, different destination information is input to the former memory board 5 and the latter memory board 5. The destination information is recorded in the memory board 5, for example, during the production process of the intermediate transfer unit 150 or at the time of shipment (inspection) from the factory. Specifically, the destination information may be independent information indicating the destination of the intermediate transfer unit 150, or may be included as part of the model number or individual number of the intermediate transfer unit 150. Furthermore, the main body storage unit 52 (FIG. 6), which is a storage unit of the control unit 50 (FIG. 6) provided in the apparatus main body 120, stores “verification information,” which is information that enables determination of which intermediate transfer unit 150 is compatible with the image forming apparatus 100. The verification information is registered in the main body storage unit 52, for example, during the production process of the image forming apparatus 100 or at the time of shipment (inspection) from the factory. Specifically, the verification information may be independent information to be compared with the destination information, or may be included as part of the model number or individual number of the image forming apparatus 100, or may be included in a program that determines whether specific information is included in the destination information read from the memory board 5. The control unit 50 can compare the destination information held by the intermediate transfer unit 150 with the verification information held by the apparatus main body 120, and determine whether the destinations match.It should be noted that examples of cases where different destination information is recorded on the memory board 5 are not limited to the above examples. For example, an example would be a case where the characteristics of parts such as the intermediate transfer belt differ between an intermediate transfer unit for a predecessor model and an intermediate transfer unit for a successor model, but the intermediate transfer unit can be attached to the device body of either model.

[0052] In this embodiment, characteristic value information is stored in the memory board 5. "Characteristic value information" refers to information related to the inherent characteristics of the elements constituting the intermediate transfer unit 150. The characteristic value information is stored in the memory board 5, for example, during the production process of the intermediate transfer unit 150 or at the time of shipment (inspection) from the factory. For example, the intermediate transfer belt 1 may have a unique belt resistance (electrical resistance) for each product (model, model number), lot, or individual. It may be desirable to set the primary transfer voltage and secondary transfer voltage to match the belt resistance. If it is unclear what belt resistance the intermediate transfer unit 150 installed on the device main body 120 has, the following may be necessary. For example, in order to set the optimal primary transfer voltage and secondary transfer voltage, several stages of adjustment may be required, such as before image formation, to detect the belt resistance and set the optimal primary transfer voltage and secondary transfer voltage. Therefore, if the belt resistance value is recorded in advance as characteristic value information on the memory board 5, the control unit 50 can read the belt resistance value from the memory board 5 when the intermediate transfer unit 150 is attached to the apparatus main body 120. This makes it possible to eliminate or simplify the above-mentioned adjustment operations for setting optimal primary transfer voltages and secondary transfer voltages. The same applies to the electrical resistance values ​​of the primary transfer member and the secondary transfer member. Storing the characteristic value information on the memory board 5 enables optimal operational control and management of the image forming apparatus 100 for each product (model, type number), lot, or individual intermediate transfer unit 150, thereby improving the operational stability and quality of the image forming apparatus 100.

[0053] In this embodiment, the memory board 5 stores usage history information, which is information related to the usage history of the intermediate transfer unit 150 in the image forming apparatus 100. The "usage history information" refers to information such as the number of sheets of recording material P printed using the intermediate transfer unit 150 in the image forming apparatus 100 and the ratio of monochrome images to color images. For example, the control unit 50 can acquire a cumulative value of the number of printed sheets (which may be the number of sheets converted to a predetermined size) as an index value related to the usage amount of the intermediate transfer belt 1 since its initial use (when new), and update and store the index value in the memory board 5. The index value may be any value correlated with the usage amount of the intermediate transfer belt 1 associated with the operation of the image forming apparatus 100. For example, the printing time, the transport distance (or number of rotations), or the transport time (or rotation time) of the intermediate transfer belt 1 may be used. The control unit 50 can acquire the index values ​​related to monochrome image printing and color image printing, respectively, to determine the ratio of monochrome images to color images, and update and store the index value in the memory board 5. The method for acquiring information about the ratio of monochrome images to color images is not limited to the above method. When the intermediate transfer unit 150 is recycled after being collected from the market, it is possible to reuse parts that are used less frequently and replace only parts that are nearing the end of their life with new parts based on this usage history information.

[0054] The control unit 50 may be configured to reset at least a portion of the usage history information (e.g., the number of printed sheets) to an initial value (e.g., zero) when the intermediate transfer belt 1 is replaced with a new one (when it is detected that the intermediate transfer belt 1 is new). The control unit 50 may also be configured to notify (e.g., display) at least a portion of the usage history information (e.g., the number of printed sheets) to serve as a guide for when to replace the intermediate transfer belt 1. This notification can be made by an operation unit 60 (FIG. 6) provided on the device main body 120 or an external device in response to a predetermined operation by an operator, or at a predetermined timing, on the operation unit 60 or an external device. Furthermore, when at least a portion of the usage history information (e.g., the number of printed sheets) exceeds a predetermined threshold, information urging replacement of the intermediate transfer belt 1 may be automatically notified (e.g., displayed).

[0055] 5. Control Configuration 6 is a schematic block diagram showing the control configuration of the image forming apparatus 100 of this embodiment. The apparatus main body 120 of the image forming apparatus 100 is provided with a control unit 50 that controls each unit of the image forming apparatus 100 in an integrated manner. The control unit 50 has a CPU 51, which is a central element that performs arithmetic processing as an arithmetic processing means, and a main body storage unit 52, which is a storage unit (storage medium) such as a ROM or RAM as a storage means. The ROM stores a control program, a pre-determined data table, etc., and the RAM stores information input to the control unit 50, detected information, calculation results, etc. The control unit 50 also has an input / output circuit (input / output unit) (not shown) for sending and receiving signals between the control unit 50 and each unit.

[0056] The control unit 50 is connected to various components of the image forming apparatus 100 (such as the image forming unit S, drive devices for the intermediate transfer belt 1 and conveying members for the recording material P, various power sources, and various sensors). The control unit 50 is also connected to a counter 80 serving as a counting unit for counting the number of printed sheets as usage history information of the intermediate transfer unit 150. The control unit 50 is also connected to a read / write circuit (read / write unit) 80 for reading and writing information from and to a memory board 5 provided in the intermediate transfer unit 150. A contact spring 6a serving as a contact member provided in a contact holder 6 (described later) is connected to the read / write circuit 80. The control unit 50 is also connected to an operation unit (operation panel) 60 provided in the apparatus main body 120. The operation unit 60 has a display unit (display means) for displaying information under the control of the control unit 50, and an input unit (input means) for inputting information to the control unit 50 based on operations by an operator such as a user or a service representative. The operation unit 60 may be configured with a touch panel having the functions of a display unit and an input means. Furthermore, the control unit 50 is connected to an external device (not shown) such as an image reading device (not shown) connected to the image forming apparatus 100 and a personal computer.

[0057] 6. Memory board placement <Overview of memory board layout> Next, the arrangement of the memory board 5 provided in the intermediate transfer unit 150 in this embodiment will be described.

[0058] FIG. 2 is a schematic perspective view of the intermediate transfer unit 150 in this embodiment, and FIG. 5 is a schematic perspective view of the intermediate transfer unit 150 in this embodiment with the belt cleaning device 160 removed from the frame unit 200. As shown in FIG.

[0059] As described above, the intermediate transfer unit 150 is configured to include the belt cleaning device 160 and the frame unit 200. Also, as described above, the intermediate transfer unit 150 is configured so that the belt cleaning device 160 can be detached from the frame unit 200.

[0060] In this embodiment, as shown in FIG. 5, the memory board 5 is provided on the frame unit 200 side of the belt cleaning device 160 and the frame unit 200 that constitute the intermediate transfer unit 150.

[0061] As described above, in the intermediate transfer unit 150 in which the belt cleaning device 160 is detachable, if the memory board 5 is attached to the belt cleaning device 160, the usage history of the frame unit 200 side becomes unknown when the belt cleaning device 160 is replaced. In contrast, by providing the memory board 5 on the frame unit 200 side as in this embodiment, the usage history of the frame unit 200 side can be continuously saved on the memory board 5 even when the belt cleaning device 160 is replaced in the market.

[0062] As shown in FIG. 3 , in this embodiment, the belt cleaning device 160 is attached to the bearing member 205 of the tension roller 202. Therefore, the belt cleaning device 160 slides in conjunction with the bearing member 205, which applies tension to the intermediate transfer belt 1. In this configuration, if the memory board 5 is provided in the belt cleaning device 160, the following problem may arise. That is, when the intermediate transfer unit 150 is set in the apparatus main body 120, the tension applied to the intermediate transfer belt 1 may be weakened by the biasing force from the spring that biases the contact holder and the contact spring that serve as the contact member, which are located on the apparatus main body 120 side. In contrast, by providing the memory board 5 on the frame unit 200 side as in this embodiment, the memory board 5 can be provided in the intermediate transfer unit 150 without affecting the tension applied to the intermediate transfer belt 1.

[0063] As described above, by providing the memory board 5 on the frame unit 200 side, even when the belt cleaning device 160 is replaced, the usage history of the frame unit 200, which has more components than the belt cleaning device 160, can be retained on the memory board 5. This makes it possible, even in such cases, to reuse the components of the frame unit 200 of the intermediate transfer unit 150 that has been collected from the market, by reusing the less frequently used components and replacing only the components that are nearing the end of their life with new ones. In other words, by continuing to use the components that do not need to be replaced, it is possible to provide an environmentally friendly intermediate transfer unit 150.

[0064] <Front-to-back position of memory board> Next, the position in the front-rear direction of the memory board 5 provided in the intermediate transfer unit 150 in this embodiment will be described. Fig. 7 is a schematic diagram of the vicinity of the intermediate transfer unit 150 arranged in a predetermined position (mounting position) in the device main body 120, as seen from above. Fig. 8 is a perspective view of the vicinity of the front rail 10F provided in the device main body 120.

[0065] As shown in FIG. 7, front and rear frames within the apparatus main body 120 are provided with a front rail 10F and a rear rail 10R, which are rail-shaped mounting portions for mounting the intermediate transfer unit 150. Also, as shown in FIG. 7, a drive unit 300 is provided in the rear frame within the apparatus main body 120. The drive unit 300 includes a drive gear 301 as a drive transmission member that transmits a driving force to the drive roller 201, a gear biasing spring 302 as a biasing member that biases the drive gear 301, and a drive motor 303 as a drive source. The drive gear 301 is biased in a direction from the rear side to the front side by the gear biasing spring 302. When the intermediate transfer unit 150 is mounted in the apparatus main body 120, the drive gear 301 is connected to a drive receiving gear (not shown) provided at the rear end of the drive roller 201. In this embodiment, as the intermediate transfer unit 150 moves, the intermediate transfer unit 150 retracts the drive gear 301 against the biasing force of the gear biasing spring 302, and then this state is released, thereby connecting the drive gear 302 to the drive receiving gear. The intermediate transfer unit 150 is biased forward by the drive gear 301 (more specifically, by the gear biasing spring 302 via the drive gear 301 and the drive roller 201). Furthermore, when the drive motor 303 rotates, a driving force is transmitted to the drive roller 201 via the drive gear 301, causing the intermediate transfer belt 1 to rotate.

[0066] As shown in FIG. 8 , a contact holder 6 is provided on the front rail 10F as a contact holding portion that holds a contact member on the device main body 120 side. In this embodiment, the contact holder 6 is integrally formed with the front rail 10F. That is, in this embodiment, the contact holder 6 is fixed to the device main body 120 (front rail 10F) so as not to move relative to the device main body 120 (front rail 10F). The contact holder 6 is provided with a contact spring 6a as a contact member for electrically connecting (establishing conduction) with the memory board 5. The contact spring 6a is provided so as to protrude from the front side to the rear side and to be elastically deformable in the front-rear direction. In this embodiment, a plurality of contact springs 6a are provided and arranged in the vertical direction corresponding to the memory contacts 5a of the memory board 5. The contact holder 6 is provided in a position where the memory contacts 5a and the contact springs 6a come into conductive contact with each other when the intermediate transfer unit 150 is attached to the device main body 120. The contact spring 6a is connected to a read / write circuit 80 (FIG. 6) provided in the device body 120 via an electric cable 7 provided in the device body 120.

[0067] 2 and 7, a memory board 5 is provided on a side structure 261 on the front side of the frame 206 of the frame unit 200 of the intermediate transfer unit 150. Thus, the memory board 5 is provided on a side (end) of the frame unit 200 in a direction intersecting (substantially perpendicular in this embodiment) the insertion direction (mounting direction) of the intermediate transfer unit 150 into the apparatus main body 120. The insertion direction of the intermediate transfer unit 150 into the apparatus main body 120 (the direction of arrow B2 in FIG. 4) is also simply referred to as the "unit insertion direction." In this embodiment, the unit insertion direction is a direction intersecting (substantially perpendicular in this embodiment) the width direction of the intermediate transfer belt 1 (the direction of the rotation axes of the multiple tension rollers 201-204) and is substantially horizontal. In particular, in this embodiment, the memory board 5 is provided on a side of the front side of the frame unit 200 in a direction intersecting (substantially perpendicular in this embodiment) the unit insertion direction. That is, in this embodiment, the memory board 5 is provided on the side of the frame unit 200 opposite the side on which the drive gear 301 (gear biasing spring 302) that biases the intermediate transfer unit 150 is provided, in a direction intersecting (substantially perpendicular in this embodiment) the unit insertion direction. The memory board 5 is fixed to a memory retaining portion 263 that is integrally formed with a front side structure 261 of the frame 206. That is, in this embodiment, the memory board 5 is fixed to the memory retaining portion 263 of the frame 206 so as not to move relative to the frame 206. The memory board 5 is provided with memory contacts 5a as contact portions for electrically connecting (establishing conduction) with the contact springs 6a on the device main body 120 side. The memory contacts 5a of the memory board 5 face forward. The memory contacts 5a are fixed so as not to move on the memory board 5. In this embodiment, a plurality of memory contacts 5a are arranged vertically. By connecting the memory contact 5 a and the contact spring 6 a, the control unit 50 can write and read information to and from the memory board 5 via the read / write circuit 80 .

[0068] 2 and 7, a protrusion 206a is provided on the front side structure 261 of the frame 206 as a positioning portion for the intermediate transfer unit 150 in the front-rear direction. Also, as shown in FIGS. 7 and 8, the front rail 10F is provided with a contact portion 10a as a positioning portion for the intermediate transfer unit 150 in the front-rear direction on the device main body 120, against which the protrusion 206a can abut. When the intermediate transfer unit 150 is attached to the device main body 120, the intermediate transfer unit 150 is urged forward by the drive gear 301. Then, the protrusion 206a abuts against the contact portion 10a, thereby positioning the intermediate transfer unit 150 in the front-rear direction.

[0069] In this way, by providing the memory board 5 on the side of the frame unit 200 in the direction intersecting the unit insertion direction, the structure of the connection between the contact member on the device main body 120 and the memory board 5 on the intermediate transfer unit 150 can be simplified. That is, for example, when providing a memory board in a belt cleaning device provided at the leading end of the intermediate transfer unit in the unit insertion direction, the following configuration may be required. The belt cleaning device may be attached coaxially (e.g., on a bearing member) with the rotation axis of the tension roller of the intermediate transfer belt. For example, if the tension roller is a tension roller or a steering roller, the belt cleaning device moves in conjunction with the movement of the tension roller. To accommodate such movement of the belt cleaning device, it may be necessary to make the contact holder on the device main body movable relative to the frame of the device main body, or to make the memory holding member on the intermediate transfer unit movable relative to the main body of the intermediate transfer unit. Furthermore, it may be necessary to bias the contact holder on the device main body or the memory holding member on the intermediate transfer unit with a spring. In contrast, the side of the frame unit 200, for example, the side structure of the frame 206, does not substantially move when the intermediate transfer unit 150 is attached to the apparatus main body 120. Therefore, when the memory board 5 is provided on the side of the frame unit 200 in the direction intersecting the unit insertion direction, it is possible to simplify the structure of the connection between the contact holder 6 on the apparatus main body 120 side and the memory board 5 on the intermediate transfer unit 150 side. In addition, the urging force from the spring that urges the contact holder on the apparatus main body 120 side or the contact spring as a contact member does not affect the tension applied to the intermediate transfer belt 1.

[0070] In particular, in this embodiment, the intermediate transfer unit 150 is urged forward by the drive gear 301, and is positioned in the front-to-rear direction by the protrusion 206a hitting the abutment portion 10a of the front rail 10F. This allows the memory contacts 5a and the contact spring 6a to be connected while the memory board 5 is urged forward. Therefore, the memory contacts 5a and the contact spring 6a can be connected in a stable position. Furthermore, the memory contacts 5a and the contact spring 6a can be sufficiently connected without providing a configuration for urging the contact holder 6 with a separate spring or the like.

[0071] <Left and right position of memory board> Next, we will explain the left-right position of the memory board 5 provided in the intermediate transfer unit 150 in this embodiment. Figure 9 is a schematic diagram of the vicinity of the intermediate transfer unit 150 arranged inside the device main body 120 viewed from above, and shows the tendency of the intermediate transfer unit 150 to change in posture in an exaggerated manner.

[0072] In this embodiment, as described above, the image forming apparatus 100 includes a drive gear 301 (gear biasing spring 302) as a means for biasing the intermediate transfer unit 150 forward. The drive gear 301 is located upstream (to the right) of the center of the frame unit 200 (more specifically, the frame 206; the same applies below) of the intermediate transfer unit 150, which is located at a predetermined position (mounting position) within the apparatus main body 120, in the unit insertion direction. In other words, the drive roller 201 is located upstream (to the right) of the center of the frame unit 200 in the unit insertion direction. In this embodiment, the image forming apparatus 100 includes the following means for biasing the intermediate transfer unit 150 forward, in addition to the drive gear 301 (gear biasing spring 302): First, there are contact members (not shown) for applying a primary transfer voltage to each primary transfer roller 106; and there is also a movement mechanism drive gear (not shown) for transmitting drive to the movement mechanism that moves the primary transfer roller 106 and other components. The contact members for applying these primary transfer voltages and the movement mechanism drive gear are provided on the side structure 262 (FIG. 2) at the rear side of the frame 206 of the frame unit 200 in the apparatus main body 120. However, in this embodiment, of the urging forces applied to the intermediate transfer unit 150 by each of these means for urging the intermediate transfer unit 150 forward, the urging force applied to the intermediate transfer unit 150 by the drive gear 301 is the largest.

[0073] 9, the right side of the intermediate transfer unit 150 abuts against the front rail 10F. However, the left side of the intermediate transfer unit 150 may not abut against the front rail 10F because the force urging the intermediate transfer unit 150 forward is weak. Therefore, if the memory board 5 is positioned downstream (left side) of the center of the frame unit 200 in the unit insertion direction, the following may occur: In other words, the memory contact 5a and the contact spring 6a may not be able to be connected, or the connection between them may become unstable.

[0074] In contrast, in this embodiment, the memory board 5 is disposed upstream (to the right) of the center of the frame unit 200 in the unit insertion direction. That is, in this embodiment, the memory board 5 is disposed on the same side of the center of the frame unit 200 as the side on which the drive gear 301 is provided in the unit insertion direction. Thus, in this embodiment, the memory board 5 is disposed on the same side of the center of the frame unit 200 as the position where the intermediate transfer unit 150 abuts against the front rail 10F due to the biasing force of the drive gear 301 in the unit insertion direction. Therefore, the memory contact 5a and the contact spring 6a can be connected in a more stable position.

[0075] It is more preferable that the memory board 5 be disposed upstream (to the right) of the rotation axis of the primary transfer roller 106K, which is located at the most upstream position in the unit insertion direction (the most downstream position in the rotation direction of the intermediate transfer belt 1). In this embodiment, the memory board 5 is disposed upstream (to the right) of the rotation axis of the primary transfer roller 106, which is located at the most upstream position, and downstream (to the left) of the rotation axis of the drive roller 201 in the unit insertion direction. This brings the memory board 5 closer to the position where it is biased forward by the drive gear 301, further stabilizing the connection between the memory contact 5a and the contact spring 6a.

[0076] 2 and 9, the front side structure 261 of the frame 206 is provided with an abutment portion 206b as a left-right positioning portion on the intermediate transfer unit 150 side. The abutment portion 206b is provided adjacent to the memory board 5 on the upstream side (right side) of the memory board 5 in the unit insertion direction. Also, as shown in FIGS. 8 and 9, the front rail 10F is provided with a regulating portion 10b as a left-right positioning portion on the device main body 120 side, against which the abutment portion 206b can abut. When the intermediate transfer unit 150 is attached to the device main body 120, the abutment portion 206b abuts against the regulating portion 10b, thereby positioning the intermediate transfer unit 150 in the left-right direction. In this case, it is more preferable that the abutment portion 206b and the memory board 5 be disposed upstream (right side) of the rotation axis of the primary transfer roller 106 located at the most upstream position and downstream (left side) of the rotation axis of the drive roller 201 in the unit insertion direction. As a result, the memory board 5 is disposed near the position where the intermediate transfer unit 150 is positioned in the left-right direction, so that the memory contacts 5a and the contact springs 6a can be connected in a more stable position.

[0077] Note that arranging the memory board 5 upstream (to the right) of the center of the frame unit 200 in the unit insertion direction is also preferable from the following other perspective. That is, by arranging the memory board 5 upstream (to the right) of the center of the frame unit 200 in the unit insertion direction, the movement distance of the memory board 5 within the device body 120 when attaching or detaching the intermediate transfer unit 150 to or from the device body 120 is shorter than when the memory board 5 is arranged downstream (to the left). This makes it possible to reduce the possibility of malfunctions occurring due to the memory board 5 coming into contact with components within the device body 120 when attaching or detaching the intermediate transfer unit 150 to or from the device body 120.

[0078] <Memory board vertical position> Next, the vertical position of the memory board 5 provided in the intermediate transfer unit 150 in this embodiment will be described.

[0079] As described above, when the intermediate transfer unit 150 is attached to or detached from the apparatus main body 120, the intermediate transfer unit 150 is supported and moved by the front rail 10F and the rear rail 10R.

[0080] As shown in FIG. 2, a positioning boss 206c, a guide boss 206d, a positioning surface 206e, and a guide surface 206f are provided on the front side structure 261 of the frame 206. In the unit insertion direction, the guide boss 206d is provided near the downstream end, and the positioning boss 206c is provided adjacent to the upstream side of the guide boss 206d. The guide boss 206d and the positioning boss 206c are provided so as to protrude toward the outside of the intermediate transfer unit 150 in a direction intersecting (substantially perpendicular in this embodiment) the unit insertion direction. Furthermore, in the unit insertion direction, near the upstream end, a positioning surface 206e and a guide surface 206f are provided on the upper and lower sides, respectively, across the rotation axis of the drive roller 201. Furthermore, as shown in FIG. 8, an upper rail portion 10c and a lower rail portion 10d are provided on the side surface of the front rail 10F on the intermediate transfer unit 150 side (rear side) along the unit insertion direction.

[0081] The rear side structure 262 of the frame 206 is also provided with a positioning boss 206c, a guide boss 206d, a positioning surface 206e, and a guide surface 206f, which are configured similarly to those provided on the front side structure 261 (substantially symmetrical with respect to a plane that passes through the center in the width direction of the intermediate transfer belt 1 and is substantially perpendicular to the surface of the intermediate transfer belt 1). The rear rail 10R is also provided with an upper rail portion 10c and a lower rail portion 10d, which are configured similarly to those provided on the front rail 10F (substantially symmetrical with respect to a plane that passes through the center in the width direction of the intermediate transfer belt 1 and is substantially perpendicular to the surface of the intermediate transfer belt 1).

[0082] The intermediate transfer unit 150 is then moved to the left while supported by the front rail 10F and the rear rail 10R, with the guide boss 206d placed on the lower rail portion 10d and the positioning boss 206c placed on the upper rail portion 10c. At the downstream end in the unit insertion direction, the positioning boss 206c falls into the positioning recess 10c1 provided in the upper rail portion 10c, thereby positioning the intermediate transfer unit 150 in the up-down direction. At the upstream end in the unit insertion direction, the intermediate transfer unit 150 is moved to the left while the guide surface 206f is supported by the lower rail portion 10d. As described above, the abutting portion 206b of the frame 206 abuts against the restricting portion 10b of the front rail 10F (and the rear rail 10R), thereby positioning the intermediate transfer unit 150 in the left-right direction. At this time, as described above, the drive gear 301 is connected to the drive receiving gear (not shown) of the drive roller 201, and the intermediate transfer unit 150 is urged forward. As a result, the protrusion 206a of the frame 206 abuts against the abutment portion 10a of the front rail 10F, and the intermediate transfer unit 150 is positioned in the front-to-rear direction. Furthermore, at the upstream end in the unit insertion direction, the intermediate transfer unit 150 is positioned in the up-down direction as follows. That is, when the right door unit 140 is closed, the secondary transfer outer roller 107 abuts against the drive roller 201 via the intermediate transfer belt 1, and the intermediate transfer unit 150 is urged upward. As a result, the positioning surface 206e of the frame 206 abuts against the regulating surface 10e of the front rail 10F (and the rear rail 10R). As a result, the intermediate transfer unit 150 is positioned in the up-down direction.

[0083] In this embodiment, the memory contact 5a is positioned so as to be in contact with the contact spring 6a, or is in contact with the contact spring 6a, just before the abutting portion 206b abuts against the regulating portion 10b and just before the protrusion 206a abuts against the contact portion 10a. When the abutting portion 206b abuts against the regulating portion 10b and the protrusion 206a abuts against the abutting portion 10a, the memory contact 5a and the contact spring 6a are sufficiently connected. Even when the right door unit 140 is closed and the vicinity of the drive roller 201 of the intermediate transfer unit 150 is biased upward, the connection between the memory contact 5a and the contact spring 6a is maintained.

[0084] The operation for removing the intermediate transfer unit 150 from the apparatus main body 120 is the reverse of the operation for inserting it.

[0085] As described above, the intermediate transfer unit 150 has a protruding shape such as the positioning boss 206c. If the memory board 5 is positioned inside the outer shape of the intermediate transfer belt 1, the vertical position of the contact spring 6a provided on the front rail 10F will be inside the outer shape of the intermediate transfer belt 1. In this case, when the intermediate transfer unit 150 is attached to or detached from the device main body 120, the protruding shape such as the positioning boss 206c may catch on the contact spring 6a, potentially deforming the contact spring 6a. The outer shape of the intermediate transfer belt 1 refers to the outer shape of the intermediate transfer belt 1, when viewed approximately parallel to the width direction of the intermediate transfer belt 1, stretched across the multiple tension rollers 201-204 when attaching or detaching the intermediate transfer unit 150 to or from the device main body 120. To facilitate attachment or detachment of the intermediate transfer belt 1 to or from the frame 206, the outer shape of the frame 206, except for the memory retaining portion 263, when viewed approximately parallel to the width direction of the intermediate transfer belt 1, is made the same as the outer shape of the intermediate transfer belt 1.

[0086] Therefore, in this embodiment, the contact spring 6a is arranged outside the locus through which the portions of the frame unit 200 other than the memory holding portion 263 pass when the intermediate transfer unit 150 is attached to or detached from the apparatus main body 120. In particular, in this embodiment, the contact spring 6a is arranged above the locus through which the portions of the frame unit 200 other than the memory holding portion 263 pass when the intermediate transfer unit 150 is attached to or detached from the apparatus main body 120, for reasons that will be described later (FIG. 8). Then, in this embodiment, the memory board 5 is arranged at a position corresponding to the position of the contact spring 6a.

[0087] In order to prevent interference between the contact spring 6a and protruding shapes such as the positioning boss 206c, the contact spring 6a may be disposed outside the movement path of the protruding shapes within the device body 120 when the intermediate transfer unit 150 is attached to or detached from the device body 120. In this embodiment, to more reliably prevent protruding shapes such as the positioning boss 206c from getting caught on the contact spring 6a, the contact spring 6a is disposed outside the outer shape of the intermediate transfer belt 1. In particular, in this embodiment, the contact spring 6a is disposed above the outer shape of the intermediate transfer belt 1 (FIG. 8). In this embodiment, the memory board 5 is disposed outside the outer shape of the intermediate transfer belt 1 in accordance with the position of the contact spring 6a. In particular, in this embodiment, the memory board 5 is disposed above the outer shape of the intermediate transfer belt 1 (FIG. 2). In this embodiment, the entire memory board 5 is disposed outside the outer shape of the intermediate transfer belt 1 (in this embodiment, above the outer shape of the intermediate transfer belt 1). However, in order to sufficiently prevent protruding shapes such as the positioning boss 206c from getting caught on the contact spring 6a, at least a portion of the memory board 5 should be positioned outside the outer shape of the intermediate transfer belt 1 (in this embodiment, above the outer shape of the intermediate transfer belt 1).

[0088] This prevents protruding shapes such as the positioning boss 206c from getting caught on the contact spring 6a when attaching or detaching the intermediate transfer unit 150 to or from the apparatus main body 120. Furthermore, by arranging the memory board 5 above the outer shape of the intermediate transfer belt 1, the memory board 5 can be arranged at a position away from the developing device 104 across the intermediate transfer belt 1 (on the opposite side of the image forming unit S across the intermediate transfer belt 1). In the image forming unit S where the photosensitive drum 101 and the developing device 104 are located, toner scattered from the developing device 104 and the like may be floating around. Therefore, by arranging the memory board 5 above the outer shape of the intermediate transfer belt 1 and at a position away from the developing device 104 across the intermediate transfer belt 1, adhesion of toner to the memory board 5 can be prevented.

[0089] <Relationship between the attachment / detachment direction of the intermediate transfer belt and the position of the memory board> Next, a description will be given of the relationship between the direction in which the intermediate transfer belt 1 is attached to and detached from the frame 206 and the position of the memory board 5. Figure 10 is an exploded perspective view of the intermediate transfer unit 150, showing the state when the intermediate transfer belt 1 is attached to the frame 206.

[0090] When the intermediate transfer belt 1 is assembled to the frame 206, the frame 206 is assembled with the drive roller 201, the first and second auxiliary rollers 203 and 204, and the primary transfer rollers 106Y, 106M, 106C, and 106K. Meanwhile, at this time, the frame 206 is in a state in which the rear bearing member 205 of the tension roller 202, the tension roller 202, the belt cleaning device 160, and the rear handle 210R have been removed. The frame 206 is provided with handles 210F and 210R at the right ends of the front and rear side structures 261 and 262, respectively, for the operator to operate when attaching or detaching the intermediate transfer unit 150 to or from the apparatus main body 120. The handles 210F and 210R are provided so as to protrude upstream (to the right) from the outer shape of the intermediate transfer belt 1 in the unit insertion direction. In order to attach or detach the intermediate transfer belt 1 to or from the frame 206, the rear handle 210R is detachable from the rear side structure 262. The front handle 210F is integrally formed with the front side structure 261. The intermediate transfer belt 1 is moved substantially parallel to its width direction in the direction from the rear to the front, as indicated by the arrow C1 in the figure, and assembled to the frame 206.

[0091] To assemble the endless intermediate transfer belt 1 to the frame 206, the outer periphery of the frame 206 when viewed in the direction of the arrow C1 in the figure, i.e., in a direction substantially parallel to the width direction of the intermediate transfer belt 1, must be shorter than the inner periphery of the intermediate transfer belt 1. Here, as described above, in this embodiment, the memory board 5 is disposed outside the outer shape of the intermediate transfer belt 1.

[0092] Therefore, in this embodiment, the memory board 5 is disposed downstream (front) in the assembly direction (direction of arrow C1 in the figure) of the intermediate transfer belt 1 to the frame 206. This makes it possible to dispose the memory board 5 in the frame unit 200 without affecting the insertion and removal of the intermediate transfer belt 1 into and from the frame 206.

[0093] 10, the intermediate transfer belt 1 is assembled to the frame 206, and then the tension roller 202 (and the rear bearing member 205), the rear handle 210R, and the belt cleaning device 160 are assembled to the frame 206. This completes the intermediate transfer unit 150.

[0094] The operation for removing the intermediate transfer belt 1 from the frame 206 is the reverse of the operation for assembling it.

[0095] Thus, in this embodiment, the image forming apparatus 100 has an image forming section S that forms a toner image on an image carrier (photosensitive drum) 101, an intermediate transfer unit 150 for transferring the toner image formed by the image forming section S onto a recording material P, which includes an intermediate transfer belt 1 onto which the toner image is transferred from the image carrier 101, a plurality of tension rollers 201 to 204 that tension the intermediate transfer belt 1, and a frame unit 200 that has a frame 206 that supports the plurality of tension rollers 201 to 204, a cleaning device (belt cleaning device, cleaning unit) 160 that removes toner from the surface of the intermediate transfer belt 1, the intermediate transfer unit 150 having a memory board 5 having a memory section 5b and a contact section 5a, and a contact member 6a that can be connected to the contact section 5a of the memory board 5. In this embodiment, the intermediate transfer unit 150 is detachable from the apparatus main body 120 of the image forming apparatus 100, the cleaning device 160 is detachable from the frame unit 200, the intermediate transfer unit 150 is configured to be detachable from the apparatus main body 120 with the cleaning device 160 attached to the frame unit 200, and the memory board 5 is provided in the frame unit 200. In this embodiment, the memory board 5 is provided on a side of the frame unit 200 in a direction intersecting the insertion direction of the intermediate transfer unit 150 into the apparatus main body 120. In this embodiment, the memory board 5 is provided so that the contact portion 5a faces outward from the intermediate transfer unit 150 in a direction intersecting the insertion direction. In this embodiment, the image forming apparatus 100 has a biasing means (drive gear) 301 that biases the intermediate transfer unit 150, which is arranged at a predetermined position within the apparatus body, from one side of the frame unit 200 to the other side in a direction intersecting the insertion direction, and the memory board 5 is provided on the side of the frame unit 200 opposite to the side on which the biasing means 301 is provided in the direction intersecting the insertion direction. In this embodiment, the insertion direction is a direction intersecting the width direction of the intermediate transfer belt 1, the multiple tension rollers 201 to 204 include a drive roller 201 that rotates the intermediate transfer belt 1, and the biasing means 301 is a drive transmission member (drive gear) 301 that transmits a drive force to the drive roller 201.In this embodiment, the drive roller 201 is located upstream of the center of the frame unit 200 in the insertion direction, and the memory board 5 is located upstream of the center of the frame unit 200 in the insertion direction.

[0096] In this embodiment, the image forming apparatus 100 includes a plurality of image forming sections S, and the frame unit 200 includes a plurality of primary transfer rollers 106 arranged along the width direction of the intermediate transfer belt 1 to transfer toner images from the image carriers 101 to the intermediate transfer belt 1, corresponding to the plurality of image forming sections S, respectively. The memory board 5 is located upstream of the rotation axis of the primary transfer roller 106K that is located at the most upstream position among the plurality of primary transfer rollers 106, and downstream of the rotation axis of the drive roller 201. In this embodiment, the frame unit 200 includes a positioning section (abutment section) 206b that abuts against the apparatus main body 120 to determine the position of the intermediate transfer unit 200 in the insertion direction within the apparatus main body 120. The positioning section 206b is located upstream of the rotation axis of the primary transfer roller 106K that is located at the most upstream position, and downstream of the rotation axis of the drive roller 201, in the insertion direction. Furthermore, in this embodiment, the frame unit 200 has a protrusion (positioning boss) 206c that protrudes toward the outside of the frame unit 200 and is supported by the apparatus main body 120 when the intermediate transfer unit 150 is inserted into the apparatus main body 120, and the contact member 6a is located outside the movement trajectory of the protrusion 206c within the apparatus main body 120 when the intermediate transfer unit 150 is inserted into the apparatus main body 120. Furthermore, in this embodiment, the memory board 5 is located outside the outer shape of the intermediate transfer belt 1 that is stretched by the multiple stretching rollers 201 to 204. Particularly, in this embodiment, the memory board 5 is located on the opposite side of the image forming unit S with the intermediate transfer belt 1 interposed therebetween within the apparatus main body 120. Furthermore, in this embodiment, the memory board 5 is located downstream in the assembly direction of the intermediate transfer belt 1 to the frame 206.

[0097] As described above, according to this embodiment, by attaching the memory board 5 to the frame unit 200, the usage history of the frame unit 200 can be retained on the memory board 5 even if the belt cleaning device 160 is replaced. This facilitates the reuse of reusable parts in the frame unit 200 collected from the market. Therefore, an environmentally friendly intermediate transfer unit 150 can be provided. Thus, according to this embodiment, in a configuration in which the belt cleaning device is detachable from the frame unit of the intermediate transfer unit, information regarding the usage history of the frame unit can be obtained even if the belt cleaning device is replaced. Furthermore, according to this embodiment, by providing the memory board on the side of the intermediate transfer unit in a direction intersecting the unit insertion direction, the configuration of the connection between the memory board on the intermediate transfer unit and the contact members on the main body of the image forming apparatus can be simplified.

[0098] [Example 2] Next, another embodiment of the present invention will be described. The basic configuration and operation of the image forming apparatus of this embodiment are the same as those of the image forming apparatus of embodiment 1. Therefore, in the image forming apparatus of this embodiment, elements having the same or corresponding functions or configurations as those of the image forming apparatus of embodiment 1 are assigned the same reference numerals as those of embodiment 1, and detailed descriptions thereof will be omitted.

[0099] In this embodiment, several modifications regarding the arrangement of the memory substrate 5 and the like will be described.

[0100] In the first embodiment, a configuration in which the memory board 5 is disposed on the front side has been described, in which the drive gear 301 that biases the intermediate transfer unit 150 forward is disposed on the rear side. Alternatively, a configuration in which the memory board 5 is disposed on the rear side is also possible. FIG. 11 is a schematic diagram of the vicinity of the intermediate transfer unit 150 in such a configuration, viewed from above. In this example, the memory board 5 is disposed on the rear side of the frame unit 200, and the contact holder 6 is disposed on the rear rail 10R. Also, in this example, a contact biasing spring 8, which is a biasing member serving as a contact member biasing means that biases the contact holder 6, is disposed on the rear rail 10R. The contact holder 6 is biased forward by the contact biasing spring 8 and moves toward the frame unit 200. The contact holder 6 may also be configured to abut against the frame unit 200. As a result, even when the intermediate transfer unit 150 is biased forward by the drive gear 301, the contact biasing spring 8 is sufficiently extended, thereby enabling sufficient connection between the memory contact 5a and the contact spring 6a. In this way, the memory board 5 may be provided on the same side of the frame unit 200 as the side on which a biasing means is provided that biases the intermediate transfer unit 150 from one side of the frame unit 200 to the other side in the direction intersecting the unit insertion direction. The image forming apparatus 100 may also have a contact member biasing means (contact biasing spring) 8 that biases the contact member 6a toward the frame unit 200.

[0101] In addition, in the first embodiment, a configuration was described in which the drive gear 301 that urges the intermediate transfer unit 150 forward is provided upstream (to the right) of the center of the frame unit 200 in the unit insertion direction, and the memory board 5 is provided upstream (to the right) of the center of the frame unit 200. Alternatively, a configuration in which the memory board 5 is provided downstream (to the left) of the center of the frame unit 200 in the unit insertion direction may be used. FIG. 12 is a schematic diagram of the vicinity of the intermediate transfer unit 150 in such a configuration, as viewed from above. FIG. 13 is a schematic perspective view of the intermediate transfer unit 150 in this example. In this example, the memory board 5 is provided on the front side of the frame unit 200, and the contact holder 6 is provided on the front rail 10F. In this example, the drive gear 301 that urges the intermediate transfer unit 150 forward is provided upstream (to the right) of the center of the frame unit 200 in the unit insertion direction. In this example, a biasing roller 9 that biases the intermediate transfer unit 150 forward is also provided downstream (left side) of the center of the frame unit 200 in the unit insertion direction. This biasing roller 9 is biased forward by a roller biasing spring 9a. This allows the intermediate transfer unit 150 to abut against the front rail 10F even on the downstream side (left side) in the unit insertion direction. Therefore, with the memory board 5 biased forward, the memory contact 5a and the contact spring 6a can be connected in a stable position.

[0102] In addition, in the first embodiment, the configuration in which the memory substrate 5 is disposed above the outer shape of the intermediate transfer belt 1 has been described. Alternatively, the memory substrate 5 may be disposed below the outer shape of the intermediate transfer belt 1 (on the same side as the image forming unit S relative to the intermediate transfer belt 1). Even with such a configuration, for example, by adjusting the airflow within the image forming apparatus 100 and sufficiently preventing toner leaking from the developing device 104 from moving toward the memory substrate 5, it is possible to prevent toner from adhering to the memory substrate 5. FIG. 14 is a schematic perspective view of the intermediate transfer unit 150 in another example in which the memory substrate 5 is disposed below the outer shape of the intermediate transfer belt 1. In this example, a wall 209 serving as a shielding member is provided near the memory substrate 5. The wall 209 is provided on the front side structure 261 of the frame 206 between the image forming unit S and the memory substrate 5. This configuration makes it possible to prevent toner from adhering to the memory substrate 5, even when the memory substrate 5 is disposed below the outer shape of the intermediate transfer belt 1.

[0103] In the first embodiment, the memory board 5 is disposed above the outer shape of the intermediate transfer belt 1. Alternatively, the memory board 5 may be disposed inside the outer shape of the intermediate transfer belt 1. FIG. 15 is a schematic perspective view of the intermediate transfer unit 150 in such an example. In this example, the memory board 5 is provided on a side surface of the front side structure 261 of the frame 206. Furthermore, in this example, the positioning boss 206c is disposed above the outer shape of the intermediate transfer belt 1. Again, the contact spring 6a is disposed outside the path along which the protruding shape of the positioning boss 206c and other components pass when the intermediate transfer unit 150 is attached to or detached from the device main body 120. The memory board 5 is disposed at a position corresponding to the position of the contact spring 6a. This prevents the positioning boss 206c from getting caught on the contact spring 6a when the intermediate transfer unit 150 is attached to or detached from the device main body 120. In this way, the memory board 5 may be disposed inside the outer shape of the intermediate transfer belt 1, which is tensioned by the tension rollers 201-204. Also in this case, the contact member 6a can be configured to be positioned outside the movement trajectory of the protrusion (positioning boss) 206c supported by the device main body 120 within the device main body 120 when the intermediate transfer unit 150 is inserted into the device main body 120.

[0104] In addition, in the first embodiment, a configuration in which the belt cleaning device 160 is detachably attached to the frame unit 200 and the memory board 5 is provided on the frame unit 200 side has been described. With this configuration, as described in the first embodiment, even when the belt cleaning device 160 is replaced, the advantage of being able to record the usage history of the frame unit 200 on the memory board 5 is obtained. However, the advantage obtained by providing the memory board 5 on the side (end) of the frame unit 200 in the direction intersecting the unit insertion direction, as described in the first embodiment, can also be obtained in a configuration in which the belt cleaning device 160 is not detachably attached to the frame unit 200. In this case, as in the first embodiment, it is preferable that the memory board 5 be provided on the front side of the frame unit 200 in the direction intersecting the unit insertion direction, i.e., on the side opposite to the side on which the drive gear 301 (gear biasing spring 302) that biases the intermediate transfer unit 150 is provided. As in the first embodiment, it is preferable that the memory board 5 be disposed outside the outer shape of the intermediate transfer belt 1. Other configurations may also be similar to those of Example 1. Here, the intermediate transfer unit 150 is configured so that the belt cleaning device 160 cannot be easily removed from the frame unit 200, and the description of Example 1 will be used.

[0105] The technology described in this specification can contribute to the realization of a sustainable society, such as a decarbonized / recycling-based society. [Explanation of symbols]

[0106] 1 Intermediate transfer belt 5 Memory board 5a memory contact 6 Contact holder 6a Contact spring 10F front rail 10R rear rail 100 Image forming device 120 Device body 150 Intermediate transfer unit 160 Belt cleaning device 200 frame units 201 Drive roller 202 Tension roller 206 frames

Claims

1. an image forming unit that forms a toner image on an image carrier; an intermediate transfer unit onto which a toner image formed on the image carrier is transferred and which transfers the transferred toner image onto a recording material, the intermediate transfer unit including: an intermediate transfer belt onto which the toner image is transferred from the image carrier; a plurality of tension rollers which tension the intermediate transfer belt; and a frame unit which has a frame which supports the plurality of tension rollers; and a cleaning unit which is detachable from the frame unit and which removes toner from the surface of the intermediate transfer belt; and the intermediate transfer unit is configured to be detachable from the main body of the image forming apparatus in a state in which the cleaning unit is attached to the frame unit, The image forming apparatus is characterized in that the intermediate transfer unit is provided in the frame unit and has a memory board equipped with a storage section for storing information.

2. 2. The image forming apparatus according to claim 1, wherein the memory board is positioned outside the intermediate transfer belt in a belt width direction that intersects with the moving direction of the intermediate transfer belt.

3. The image forming apparatus according to claim 1, characterized in that the memory board has a contact portion that can be connected to a contact member provided in the device main body, and the contact portion is provided so as to face outward from the intermediate transfer unit in a belt width direction that intersects with the movement direction of the intermediate transfer belt.

4. a biasing means for biasing the intermediate transfer unit disposed at a predetermined position within the device body from one side of the frame unit toward the other side in a belt width direction intersecting with a moving direction of the intermediate transfer belt, 2. The image forming apparatus according to claim 1, wherein the memory board is provided on a side of the frame unit opposite to a side on which the biasing means is provided in the belt width direction.

5. the plurality of tension rollers include a drive roller that rotates the intermediate transfer belt, 5. The image forming apparatus according to claim 4, wherein the biasing means is a drive transmission member that transmits a drive force to the drive roller.

6. the drive roller is located upstream of the center of the frame unit in the insertion direction of the intermediate transfer unit, 6. The image forming apparatus according to claim 5, wherein the memory board is located upstream of the center of the frame unit in the insertion direction.

7. the image forming apparatus has a plurality of the image forming units, the frame unit includes a plurality of primary transfer rollers arranged along the belt width direction in correspondence with the plurality of image forming units, for transferring toner images from the image carriers to the intermediate transfer belt; 7. The image forming apparatus according to claim 6, wherein the memory board is located upstream of the rotation axis of the primary transfer roller that is located most upstream among the plurality of primary transfer rollers, and downstream of the rotation axis of the drive roller, in the insertion direction of the intermediate transfer unit.

8. the frame unit has a positioning portion that abuts against the apparatus main body to determine the position of the intermediate transfer unit in the apparatus main body in the insertion direction, 8. The image forming apparatus according to claim 7, wherein the positioning portion is located upstream of the rotation axis of the primary transfer roller located at the most upstream side in the insertion direction and downstream of the rotation axis of the drive roller.

9. 2. The image forming apparatus according to claim 1, wherein the memory board is located upstream of the center of the frame unit in the insertion direction of the intermediate transfer unit.

10. the frame unit has a protrusion that is supported by the apparatus main body when the intermediate transfer unit is inserted into the apparatus main body, the protrusion being provided so as to protrude outward from the frame unit in a belt width direction that intersects with the moving direction of the intermediate transfer belt, a contact member provided in the device body and connectable to a contact portion of the memory board; 2. The image forming apparatus according to claim 1, wherein the contact member is positioned outside a movement locus of the protrusion within the apparatus body when the intermediate transfer unit is inserted into the apparatus body.

11. 2. The image forming apparatus according to claim 1, wherein, when viewed from a belt width direction intersecting the movement direction of the intermediate transfer belt, the memory board is located outside the outer shape of the intermediate transfer belt stretched by the plurality of tension rollers.

12. 12. The image forming apparatus according to claim 11, wherein, when viewed in the belt width direction, the memory board is located on the opposite side of the intermediate transfer belt from the image forming unit.

13. 2. The image forming apparatus according to claim 1, wherein, when viewed from a belt width direction intersecting the movement direction of the intermediate transfer belt, the memory board is located inside the outer shape of the intermediate transfer belt stretched by the plurality of tension rollers.

14. the frame unit has a protrusion that is supported by the apparatus main body when the intermediate transfer unit is inserted into the apparatus main body, the protrusion being provided so as to protrude outward from the frame unit in the belt width direction, a contact member provided in the device body and connectable to a contact portion of the memory board; 14. The image forming apparatus according to claim 13, wherein the contact member is positioned outside a movement locus of the protrusion within the apparatus body when the intermediate transfer unit is inserted into the apparatus body.

15. 2. The image forming apparatus according to claim 1, wherein the memory board is located downstream in the assembly direction of the intermediate transfer belt relative to the frame.

16. 2. The image forming apparatus according to claim 1, further comprising: an operation unit provided in the apparatus main body, through which a user can manually input information that the cleaning unit has been replaced; and a control unit configured to execute a predetermined initialization operation when information that the cleaning unit has been replaced is input from the operation unit.

17. 17. The image forming apparatus according to claim 16, wherein the control unit is configured to execute a predetermined initialization operation when the intermediate transfer unit is new, based on the information stored in the memory board.

18. an image forming unit that forms a toner image on an image carrier; an intermediate transfer unit that is detachable from the main body of the image forming apparatus, to which a toner image formed on the image carrier is transferred, and which transfers the transferred toner image onto a recording material; and The intermediate transfer unit an intermediate transfer belt onto which a toner image is transferred from the image carrier; a plurality of tension rollers that tension the intermediate transfer belt; a frame supporting the plurality of tension rollers; a memory board provided on the frame so as to be positioned outside the intermediate transfer belt in a belt width direction intersecting with the moving direction of the intermediate transfer belt, the memory board including a storage unit for storing information and a connection unit connectable to a contact member provided on the device main body; An image forming apparatus comprising:

19. a frame unit including an intermediate transfer belt onto which a toner image is transferred, a plurality of tension rollers that tension the intermediate transfer belt, and a frame that supports the plurality of tension rollers; a cleaning unit that is detachable from the frame unit and removes toner from the surface of the intermediate transfer belt; a memory board provided in the frame unit and including a storage unit for storing information; An intermediate transfer unit comprising:

20. an intermediate transfer belt onto which the toner image is transferred; a plurality of tension rollers that tension the intermediate transfer belt; a frame supporting the plurality of tension rollers; a memory board provided on the frame so as to be positioned outside the intermediate transfer belt in a belt width direction intersecting with a moving direction of the intermediate transfer belt, the memory board including a memory unit for storing information and an electrically connectable contact unit; An intermediate transfer unit comprising:

Images