Image forming apparatus

Abstract

To allow replacement of a cleaning device only in an intermediate transfer unit and enable performing appropriate processing according to whether the replacement of the cleaning device only is performed or replacement of the whole intermediate transfer unit is performed.SOLUTION: An image forming apparatus has: an image carrier; and an intermediate transfer unit comprising an intermediate transfer body (intermediate transfer belt) and a cleaning device. The intermediate transfer unit is detachably attached to an apparatus body of the image forming apparatus, and the cleaning device is detachably attached to a unit body of the intermediate transfer unit. The cleaning device is provided with a storage part, and the apparatus body is provided with a control part. The control part is capable of reading, from the storage part, first information about whether the cleaning device is new or not, and second information about whether the intermediate transfer body attached to the intermediate transfer unit is new or not in such a case that the intermediate transfer unit having a new cleaning device attached thereto is attached to the apparatus body.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus, such as a copying machine, a printer, a facsimile machine, or a multifunction machine having a combination of the functions of these machines, which uses an electrophotographic system or an electrostatic recording system. [Background technology]

[0002] Conventionally, as an image forming apparatus such as a copying machine using an electrophotographic method, there is an image forming apparatus that adopts an intermediate transfer method in which a toner image that is primarily transferred from a photoreceptor as an image carrier to an intermediate transfer body is secondarily transferred to a recording material. An intermediate transfer belt that is an endless belt is often used as the intermediate transfer body. In addition, in an image forming apparatus using the intermediate transfer method, after the toner image is secondarily transferred from the intermediate transfer belt to the recording material, deposits such as toner (transfer residual toner) remaining on the intermediate transfer belt are removed by a cleaning device equipped with a cleaning member.

[0003] In an intermediate transfer type image forming apparatus, the lifespan of the intermediate transfer belt and the cleaning device is shorter than the lifespan of the main body of the image forming apparatus (hereinafter, also simply referred to as the "main body"), so it is often necessary to replace the intermediate transfer belt and the cleaning device as consumables. In addition, an intermediate transfer unit equipped with the intermediate transfer belt and the cleaning device may be detachably attached to the main body of the apparatus as a whole.

[0004] Conventionally, when an operator such as a user or a service technician replaces an intermediate transfer unit equipped with an intermediate transfer belt and a cleaning device, the operator inputs information indicating this into a control unit of the image forming device from an operation unit provided on the device body.

[0005] Then, based on this information, for example, the cumulative index value regarding the usage amount of the intermediate transfer unit since it was first used (when it was new), which is accumulated for display on the operation section of the device main body as an indication of when to replace the intermediate transfer unit, is reset.

[0006] Also, based on the information, for example, a predetermined control (herein also referred to as "initial control") may be executed when a new intermediate transfer unit is attached to the device body. For example, a cleaning device having a cleaning blade as a cleaning member that contacts an intermediate transfer belt or other object to be cleaned, and scraping off and removing adhering matter such as transfer residual toner from the surface of the moving object to be cleaned, is widely used. The cleaning blade is made of an elastic body such as rubber, and a frictional force acts on the contact portion between the cleaning blade and the object to be cleaned. If this frictional force is too large, problems such as curling of the cleaning blade may occur. Therefore, a method is known in which toner is supplied to the contact portion between the cleaning blade and the object to be cleaned, and the toner (or its external additive) is used as a lubricant to reduce the frictional force of the contact portion between the cleaning blade and the object to be cleaned. Also, when the cleaning blade is new, the frictional force acting on the contact portion between the cleaning blade and the object to be cleaned may be easily large. Therefore, as an initial control, an operation of supplying the above-mentioned toner (or its external additive) as a lubricant to the contact portion between the cleaning blade and the object to be cleaned may be executed.

[0007] Patent document 1 proposes a configuration in which, when a cartridge equipped with an image carrier and a cleaning blade is new, the amount of toner supplied to the contact point between the cleaning blade and the image carrier is greater than when the cartridge is not new. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2013-11756 A Summary of the Invention [Problem to be solved by the invention]

[0009] Incidentally, an intermediate transfer unit is generally configured so that the intermediate transfer belt and the cleaning device (particularly the cleaning member) reach the end of their life at approximately the same time. However, for example, depending on the recording material used, the difference in life between the intermediate transfer belt and the cleaning device may become large. In such cases, the cleaning device is more susceptible to the influence of the recording material and often has a shorter life. In such cases, image defects do not occur if only the cleaning device is replaced with a new one. However, if these are replaced as an integrated intermediate transfer unit, the intermediate transfer belt must also be replaced as an integrated unit, which leads to an increase in the running costs of the image forming device.

[0010] Therefore, in an intermediate transfer unit having an intermediate transfer belt and a cleaning device, it is conceivable to make the cleaning device detachable from the belt conveying section, which is another component including the intermediate transfer belt. This makes it possible to suppress an increase in the running costs of the image forming apparatus by making it possible to replace only the minimum necessary components. However, in this case, it has been found that there are problems such as the following.

[0011] That is, in this case, if the configuration is such that the operator inputs information indicating that the replacement unit has been replaced as described above, for example, when only the cleaning device is replaced, the operator may mistakenly input information indicating that the intermediate transfer belt has been replaced. In that case, for example, a malfunction may occur, such as a malfunction in which information regarding the usage amount of the intermediate transfer unit corresponding to the usage amount of the intermediate transfer belt cannot be properly displayed. Also, for example, when only the cleaning device is replaced, the operator may forget to input information indicating that fact. In that case, for example, the initial control that needs to be performed when the cleaning device is replaced with a new one may not be performed correctly, which may cause a malfunction such as curling of the cleaning blade.

[0012] Therefore, an object of the present invention is to enable replacement of only the cleaning device in an intermediate transfer unit, and to enable appropriate processing depending on whether only the cleaning device is replaced or the entire intermediate transfer unit is replaced. [Means for solving the problem]

[0013] The above object is achieved by the image forming apparatus according to the present invention. In summary, the present invention is an image forming apparatus having an intermediate transfer unit for transferring the toner image formed on the image carrier to a recording material, the intermediate transfer unit being provided with an intermediate transfer body that can be rotated to transport the toner image transferred from the image carrier to the recording material for secondary transfer, and a cleaning device that cleans the intermediate transfer body, the intermediate transfer unit being detachable from the main body of the image forming apparatus, the cleaning device being provided with a storage unit that is detachable from the main body of the intermediate transfer unit together with the cleaning device, the main body being provided with a control unit that can read information from the storage unit, and the control unit being capable of reading from the storage unit first information on whether the cleaning device is new or not, and second information on whether the intermediate transfer body attached to the intermediate transfer unit is new or not when the intermediate transfer unit with the new cleaning device attached is attached. Effect of the Invention

[0014] According to the present invention, it is possible to replace only the cleaning device in the intermediate transfer unit, and to appropriately perform processing depending on whether only the cleaning device is to be replaced or the entire intermediate transfer unit is to be replaced. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic cross-sectional view of an image forming apparatus. [Diagram 2] FIG. 2 is a schematic perspective view showing an intermediate transfer unit. [Diagram 3] FIG. 2 is a schematic perspective view showing a belt cleaning device. [Figure 4] 11A and 11B are schematic cross-sectional views for explaining a change in the tensioning form of the intermediate transfer belt. [Diagram 5] FIG. 2 is a schematic cross-sectional view of the image forming apparatus when an intermediate transfer unit is being attached or detached. [Figure 6] 2 is a schematic block diagram showing a control configuration of a main part of the image forming apparatus; [Figure 7] FIG. 4 is a flowchart showing a process when an intermediate transfer unit is attached in the first embodiment. [Figure 8] FIG. 11 is a schematic block diagram showing a control configuration of a main part of an image forming apparatus according to another embodiment of the present invention. [Figure 9] FIG. 11 is a flowchart showing a process when an intermediate transfer unit is attached in the second embodiment. [Figure 10] 1A and 1B are diagrams illustrating a mechanism by which horizontal stripe-like image defects occur. [Figure 11] FIG. 11 is a schematic block diagram showing a control configuration of a main part of an image forming apparatus according to another embodiment of the present invention. [Figure 12] FIG. 11 is a flowchart showing a process when an intermediate transfer unit is attached in the third embodiment. [Figure 13] 5 is a schematic diagram showing a stop position of the post-rotation toner band on the photosensitive drum. FIG. [Figure 14] FIG. 13 is a flowchart showing a process when an intermediate transfer unit is attached in the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, the image forming apparatus according to the present invention will be described in more detail 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 1 according to this embodiment. The image forming apparatus 1 according to this embodiment is a tandem type multifunction machine that employs an intermediate transfer method and is capable of forming full-color images using an electrophotographic method, and has the functions of a copier, printer, and facsimile machine. The image forming apparatus 1 can form an image on a sheet-shaped recording material P in response to an image signal sent from an external device such as a personal computer.

[0018] The image forming apparatus 1 has a plurality of image forming units, ie, first, second, third and fourth image forming units SY, SM, SC and SK, which form toner images of yellow (Y), magenta (M), cyan (C) and black (K), respectively. Elements having the same or corresponding functions or configurations provided for each color of yellow, magenta, cyan and black may be generally described by omitting the suffixes Y, M, C and K of the reference numerals indicating that the element is for one of the colors. In this embodiment, the image forming unit S is configured with a photosensitive drum 11, a charging roller 12, an exposure device 13, a developing device 14, a drum cleaning device 15 and the like, which will be described later.

[0019] The photosensitive drum 11, which is 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 circumferential surface) of the rotating photosensitive drum 11 is uniformly charged to a predetermined potential of a predetermined polarity (negative polarity in this embodiment) by a charging roller 12 serving as a charging means. The surface of the charged photosensitive drum 11 is scanned and exposed according to image information by an exposure device (laser scanner) 13 serving as an exposure means, and an electrostatic latent image (electrostatic image) is formed on the photosensitive drum 11. In this embodiment, the exposure device 13 is configured as one unit capable of exposing each of the photosensitive drums 11Y, 11M, 11C, and 11K. The exposure device 13 may be provided independently for each image forming section S. That is, the exposure device 13 receives image signals of each color of yellow, magenta, cyan, and black, and irradiates the surface of each photosensitive drum 11 with laser light in response to these image signals to neutralize the charge and form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 11 is developed (visualized) by the development device 14 as a developing means, which supplies toner as a developer, and a toner image is formed on the photosensitive drum 11. In this embodiment, toner charged with the same polarity as the charge polarity of the photosensitive drum 11 (negative polarity in this embodiment) adheres to the exposed portion (image portion) on the photosensitive drum 11, which has been uniformly charged and then exposed to light to reduce the absolute value of the potential (reverse development). In this embodiment, the normal charge polarity of the toner, which is the charge polarity of the toner during development, is negative polarity.

[0020] An intermediate transfer belt 101, which is an endless belt serving as an intermediate transfer body, is disposed facing the photosensitive drums 11Y, 11M, 11C, and 11K of the image forming units SY, SM, SC, and SK. The intermediate transfer belt 101 is stretched by a plurality of tension rollers. In this embodiment, the plurality of tension rollers include a secondary transfer inner roller 102, a first auxiliary roller 103, a second auxiliary roller 104, and a tension roller 105. The intermediate transfer belt 101 is driven by inputting a driving force to the secondary transfer inner roller 102, which functions as a drive roller, and rotates (moves in a circular motion) in the direction of arrow R2 (counterclockwise) in the figure at a circumferential speed (process speed) set to be substantially the same as the circumferential speed of the photosensitive drum 11. The first and second auxiliary rollers 103 and 104 form a substantially flat image transfer surface of the intermediate transfer belt 101. The tension roller 105 is biased by a tension spring 204 (FIG. 4) which is a biasing member as a biasing means, and applies a predetermined tension to the intermediate transfer belt 101. The number of rollers stretching the intermediate transfer belt 101 is not limited to four. On the inner peripheral surface side of the intermediate transfer belt 101, between the first auxiliary roller 103 and the second auxiliary roller 104, primary transfer rollers 106 as primary transfer members constituting primary transfer means are arranged corresponding to each photosensitive drum 11. The primary transfer rollers 106 press the inner peripheral surface of the intermediate transfer belt 101 toward the photosensitive drum 11. This forms a primary transfer portion (primary transfer nip portion) T1 where the photosensitive drum 11 and the intermediate transfer belt 101 come into contact with each other. The tension rollers other than the secondary transfer inner roller 102 among the plurality of tension rollers and each primary transfer roller 106 are rotated following the rotation of the intermediate transfer belt 101.

[0021] The toner image formed on the photosensitive drum 11 is transferred (primary transfer) onto the rotating intermediate transfer belt 101 by applying a predetermined pressure and an electrostatic load bias at the primary transfer section T1. During the primary transfer process, a primary transfer voltage (primary transfer bias), which is a DC voltage of a polarity opposite to the normal charging polarity of the toner (positive polarity in this embodiment) is applied to the primary transfer roller 106 from a primary transfer power source (not shown). For example, when a full-color image is formed, the toner images of each color of yellow, magenta, cyan, and black formed on each photosensitive drum 11 are transferred sequentially so as to be superimposed on the intermediate transfer belt 101. The image forming process of each color, which is processed in parallel by each image forming section S, is performed at a timing when a toner image which is primarily transferred on the downstream side is superimposed on a toner image which is primarily transferred on the upstream side onto the intermediate transfer belt 101. The number of image forming sections S is not limited to four colors, and the arrangement order of the image forming sections S for each color is not limited to the arrangement order in this embodiment.

[0022] The intermediate transfer belt 101 has a base layer and a surface layer provided on the outer peripheral surface of the base layer. The surface layer is a coating layer formed directly on the base layer to ensure the releasability of the toner. That is, the intermediate transfer belt 101 has a two-layer structure. However, the surface layer may also include a coating layer and an adhesive layer that bonds the coating layer and the base layer. That is, the intermediate transfer belt 101 may have a three-layer structure.

[0023] The base layer of the intermediate transfer belt 101 will be further described. The base layer contains any one of the resins polyimide (PI), polyamide (PA), polyphenylene sulfide (PPS), polyetherimide (PEI), and polyether ether ketone (PEEK). The base layer is made of any one of these resins with an appropriate amount of conductive filler such as carbon or ionic conductive material dispersed therein. The surface resistivity α of the base layer alone is 1.0×10 9 Ω / □≦α≦1.0×10 13 Ω / □, preferably 6.3×10 9 Ω / □≦α≦3.2×10 10The thickness D of the base layer satisfies 30 μm≦D≦100 μm.

[0024] Further description will be given of the surface layer of the intermediate transfer belt 101. The surface layer contains at least a binder resin and perfluoropolyether (PFPE). That is, the surface layer is mainly composed of a binder resin, perfluoropolyether (PFPE), a dispersant, and other additives.

[0025] The binder resin contained in the surface layer is used to disperse PFPE, ensure adhesion with the base layer, and ensure mechanical strength characteristics. Examples of the binder resin in this embodiment include styrene resin, acrylic resin, methacrylic resin, epoxy resin, polyester resin, polyether resin, silicone resin, and polyvinyl butyral resin. Mixtures of these resins can also be used. Among the above binder resins, methacrylic resin or acrylic resin (hereinafter, methacrylic resin and acrylic resin are collectively referred to as acrylic resin) is particularly preferably used.

[0026] Perfluoropolyether is an oligomer or polymer having perfluoroalkylene ether as a repeating unit. Examples of the repeating unit of perfluoroalkylene ether include perfluoromethylene ether, perfluoroethylene ether, and perfluoropropylene ether. The surface layer preferably contains a dispersant for dispersing perfluoropolyether. By containing such a dispersant, the dispersion state of PFPE in the surface layer can be more stabilized. As the dispersant, a compound having a perfluoroalkyl chain and a site having affinity for hydrocarbons (a compound having a part having a high affinity for fluorine and a part having a low affinity for fluorine) is preferably used, and a surfactant, an amphiphilic block copolymer, and an amphiphilic graft copolymer are preferably used. In this embodiment, the intermediate transfer belt 7 having two or more layers is used, but a single-layer intermediate transfer belt 101 may be used.

[0027] On the outer peripheral surface side of the intermediate transfer belt 101, a secondary transfer outer roller 16 as a secondary transfer member constituting a secondary transfer means is disposed at a position facing the secondary transfer inner roller 102 as an opposing member. The secondary transfer outer roller 16 is pressed toward the secondary transfer inner roller 102 and applies an external force to the secondary transfer inner roller 102 via the intermediate transfer belt 101. This forms a secondary transfer portion (secondary transfer nip portion) T2 where the intermediate transfer belt 101 and the secondary transfer outer roller 16 come into contact with each other. The secondary transfer outer roller 16 is rotated by the rotation of the intermediate transfer belt 101. A predetermined pressure force and an electrostatic load bias are applied to the toner image formed on the intermediate transfer belt 101 at the secondary transfer portion T2, so that the toner image is transferred (secondarily transferred) onto the recording material P that is sandwiched and conveyed between the intermediate transfer belt 101 and the secondary transfer outer roller 16. During the secondary transfer process, a secondary transfer voltage (secondary transfer bias), which is a DC voltage of the opposite polarity (positive polarity in this embodiment) to the normal charging polarity of the toner, is applied from a secondary transfer power source (not shown) to the secondary transfer outer roller 16. The secondary transfer inner roller 102 is connected to a ground potential (electrically grounded). Note that a secondary transfer voltage of the same polarity as the normal charging polarity of the toner may be applied to the secondary transfer inner roller 102 as the secondary transfer member, and the secondary transfer outer roller 16 as the opposing member may be electrically grounded.

[0028] Recording materials (sheets, transfer materials, recording media, media) P are stacked and stored in a recording material cassette 21 serving as a recording material storage section. The recording materials P stored in the recording material cassette 21 are sent out one by one from the recording material cassette 21 by a feed roller 22 serving as a feeding means or the like. The recording material P sent out from the recording material cassette 21 is conveyed through a conveying path 23 by a conveying roller pair 24 serving as a conveying means or the like to a registration roller pair 25 serving as a conveying means. After skew correction is performed on this recording material P by the registration roller pair 25, the timing is matched with the toner image on the intermediate transfer belt 101 and the recording material P is sent to the secondary transfer section T2.

[0029] The recording material P onto which the toner image has been transferred is conveyed to a fixing device 30 as a fixing means. The fixing device 30 pressurizes and heats the recording material P carrying the unfixed toner image by a fixing roller 31 equipped with a heat source and a pressure roller 32 that is in pressure contact with the fixing roller 31, thereby fixing (melting and fixing) the toner image onto the recording material P. The fixing device 30 applies a predetermined pressure force and heat quantity to the recording material P between the fixing roller 31 and the pressure roller 32. The recording material P onto which the toner image has been fixed is discharged (output) onto a discharge tray 42 provided outside the device body 2 of the image forming apparatus 1 by a pair of discharge rollers 41 or the like.

[0030] Meanwhile, the toner remaining on the photosensitive drum 11 after the primary transfer process (primary transfer residual toner) is removed from the photosensitive drum 11 and collected by the drum cleaning device 15, which is a cleaning device serving as a photosensitive body cleaning means. The drum cleaning device 15 scrapes off and collects the primary transfer residual toner from the surface of the rotating photosensitive drum 11 using a cleaning blade serving as a cleaning member that contacts the surface of the photosensitive drum 11. In addition, the toner remaining on the intermediate transfer belt 101 after the secondary transfer process (secondary transfer residual toner) and adhesions such as paper powder are removed from the intermediate transfer belt 101 and collected by the belt cleaning device 108, which is a cleaning device serving as an intermediate transfer body cleaning means. The collected materials such as the toner and paper powder collected by the drum cleaning device 15 and the belt cleaning device 108 are transported to a waste toner container (not shown) via a waste toner transport path (not shown).

[0031] In this embodiment, in each image forming station S, the photosensitive drum 11, the charging roller 12, the developing device 14, and the drum cleaning device 15 integrally constitute a process cartridge 10 that is detachably mountable to the apparatus main body 2.

[0032] In this embodiment, the intermediate transfer belt 101, the multiple tension rollers 102 to 105, the primary transfer rollers 106, and the belt cleaning device 108 integrally constitute an intermediate transfer unit 100 that is detachable from the apparatus main body 2. In the intermediate transfer unit 100, the belt cleaning device 108 is further detachable from the other components including the intermediate transfer belt 101. The intermediate transfer unit 100 will be described in more detail later.

[0033] In this embodiment, the apparatus main body 2 corresponds to the portion of the image forming apparatus 1 other than the process cartridge 10 and the intermediate transfer unit 100.

[0034] In this embodiment, an intermediate transfer unit 100 is detachably disposed at a vertically middle position within the apparatus body 2. When the intermediate transfer unit 100 is attached to the apparatus body 2, it is supported on a support frame 2f (FIG. 5) provided within the apparatus body 2. When the intermediate transfer unit 100 is attached to the apparatus body 2, a belt cleaning device 108 provided in the intermediate transfer unit 100 is connected to a waste toner transport path (not shown) provided within the apparatus body 2. In this embodiment, four process cartridges 10Y, 10M, 10C, and 10K are disposed below the intermediate transfer unit 100 from the upstream side to the downstream side along the moving direction of the image transfer surface of the intermediate transfer belt 101.

[0035] 2. Intermediate transfer unit Next, the configuration of the intermediate transfer unit 100 and its periphery in this embodiment will be further described. Here, with respect to the image forming apparatus 1 and its elements, the front side of the paper in FIG. 1 during operation of the image forming apparatus 1 is referred to as the "front side", and the rear side of the paper is referred to as the "rear side". The front-rear direction connecting the "front side" and the "rear side" is assumed to be approximately parallel to the respective rotation axis directions of the photosensitive drum 11 and the tension rollers 102 to 105 of the intermediate transfer belt 101 during operation of the image forming apparatus 1. Furthermore, with respect to the image forming apparatus 1 and its elements, the up-down direction refers to the up-down direction in the direction of gravity (vertical direction), but does not mean only directly above and directly below, but also includes the upper side and the lower side of a horizontal plane passing through the element or position of interest.

[0036] Fig. 2 is a schematic perspective view showing the intermediate transfer unit 100 immediately before being mounted at a predetermined position in the apparatus body 2, and a connecting portion 5 (described later) provided on the apparatus body 2. Fig. 3 is a schematic perspective view showing the belt cleaning device 108 removed from the intermediate transfer unit 100, and a connecting portion 5 (described later) provided on the apparatus body 2. Fig. 4 is a schematic cross-sectional view of the intermediate transfer unit 100 for explaining the tension state of the intermediate transfer belt 101 in this embodiment. Fig. 5 is a schematic cross-sectional view of the image forming apparatus 1 showing how the intermediate transfer unit 100 is attached to and detached from the apparatus body 2.

[0037] The intermediate transfer unit 100 has a unit frame 107 and a plurality of tension rollers 102-105 (FIG. 1) rotatably supported by the unit frame 107. The intermediate transfer unit 100 also has an intermediate transfer belt 101 stretched across the plurality of tension rollers 102-105, primary transfer rollers 106 (FIG. 1), and a belt cleaning device 108.

[0038] As shown in FIG. 1 and FIG. 3, the belt cleaning device 108 has a cleaning blade 181 as a cleaning member and a fixed metal plate 182 as a blade support member. The belt cleaning device 108 also has a conveying screw 183 as a conveying member and a cleaning container 184 as a housing. The cleaning blade 181 is a plate-shaped member formed of an elastic body, having a predetermined length in a longitudinal direction arranged approximately parallel to a direction approximately perpendicular to the moving direction of the surface of the intermediate transfer belt 101 and a lateral direction approximately perpendicular to the longitudinal direction, and having a predetermined thickness. In this embodiment, the cleaning blade 181 is formed of urethane rubber as an elastic body. The cleaning blade 181 is disposed opposite the tension roller 105 via the intermediate transfer belt 101 at an angle that is a counter direction to the moving direction of the surface of the intermediate transfer belt 101. In other words, the cleaning blade 181 is disposed so that a free end in the lateral direction faces the upstream side with respect to the moving direction of the surface of the intermediate transfer belt 101. The cleaning blade 181 applies an external force to the tension roller 105 via the intermediate transfer belt 101 by bringing an edge portion of a free end portion in the short side direction into contact with the surface of the intermediate transfer belt 101. The cleaning blade 181 has a fixed end portion in the short side direction adhered to a fixed metal plate 182. The fixed metal plate 182 to which the cleaning blade 181 is fixed is fixed and held by a cleaning container 184 with screws or the like. Note that, with respect to the belt cleaning device 108 and its components, the direction approximately parallel to the longitudinal direction of the cleaning blade 181 (the direction (width direction) approximately perpendicular to the moving direction of the surface of the intermediate transfer belt 101) is defined as the longitudinal direction.

[0039] The collected matter such as toner collected from the intermediate transfer belt 101 by the cleaning blade 181 is stored in a collected toner storage section 184a formed in the cleaning container 184. A conveying screw 183 (FIG. 1) is disposed in the collected toner storage section 184a. The conveying screw 183 conveys the collected matter such as toner in the collected toner storage section 184a along the longitudinal direction of the belt cleaning device 108 toward one end (for example, the front end) of the cleaning container 184. The collected matter such as toner conveyed by the conveying screw 183 is discharged from an outlet (not shown) provided at the one end of the cleaning container 184 and sent to a waste toner conveying path (not shown) provided in the device main body 2. 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 2. The waste toner container is replaced when it becomes full.

[0040] The intermediate transfer unit 100 is detachably attached to the apparatus main body 2. In the intermediate transfer unit 100, a belt cleaning device (cleaning unit) 108 is further detachably attached to a belt conveying section (belt unit) 109, which is another component including the intermediate transfer belt 101. In this embodiment, the belt conveying section 109 has a unit frame 107, a plurality of tension rollers 102 to 105 (FIG. 1), the intermediate transfer belt 101, and primary transfer rollers 106 (FIG. 1).

[0041] As shown in FIG. 5, the image forming apparatus 1 has a right door unit 3 as an opening / closing member for opening the inside of the apparatus main body 2, on the right side when the apparatus main body 2 is viewed from the front side. The right door unit 3 is configured to rotate the upper part downward (in the direction of the arrow A in FIG. 5) around a rotation shaft 3a provided at the bottom and extending in the front-rear direction to open it, and rotate the upper part upward (in the opposite direction to the direction of the arrow A in FIG. 5) to close it. The right door unit 3 is opened and closed by an operator such as a user or a service person operating a handle provided on the right door unit 3. The right door unit 3 opens at least a part of the conveying path of the recording material P from the recording material cassette 21 through the secondary transfer section T2 to the fixing device 30, so as to divide the front side (the side to which the toner image is transferred) side and the back side side of the recording material P. The secondary transfer outer roller 16 is attached to the right door unit 3 side. When the right door unit 3 is opened, the right door unit 3 is opened so that the secondary transfer outer roller 16 is separated from the intermediate transfer belt 101. When the right door unit 3 is opened, an operator can access the intermediate transfer unit 100 installed in the device main body 2.

[0042] Then, the operator can pull out the intermediate transfer unit 100 to the right side (the direction of the arrow B in FIG. 5) when the device body 2 is viewed from the front side by operating a handle provided on the unit frame 107 or the like, and remove it from the device body 2. Conversely, the operator can insert the intermediate transfer unit 100 to the left side (the direction opposite to the direction of the arrow B in FIG. 5) when the device body 2 is viewed from the front side, and attach it to the device body 2. The operator can also attach and detach the belt cleaning device 108 to and from the belt conveying section 109 of the intermediate transfer unit 100 removed from the device body 2. The intermediate transfer unit 100 is attached and detached to and from the device body 2 with the belt cleaning device 108 attached to the belt conveying section 109. As described above, the intermediate transfer unit 100 is supported and moved by a rail-shaped mounting section 2f provided on a frame body inside the device body 2, and is positioned and attached at a predetermined mounting position (FIG. 1) of the mounting section 2f. In this embodiment, the intermediate transfer unit 100 is moved in a substantially horizontal direction and is attached to and detached from the apparatus main body 2 (inserted and removed).

[0043] Incidentally, the intermediate transfer belt 101 may be configured so that only the intermediate transfer belt 101 can be replaced with respect to the belt conveying unit 109, or the entire belt conveying unit 109 can be replaced. However, in this embodiment, when the belt cleaning device 108 and the intermediate transfer belt 101 are replaced at the same time, the entire intermediate transfer belt unit 100 is replaced.

[0044] The tension form of the intermediate transfer belt 101 in this embodiment will be described with reference to FIG. 4. FIGS. 4(a), (b), and (c) show the tension form of the intermediate transfer belt 101 (position of the tension roller, posture of the belt cleaning device 108) during print standby, during color image printing, and during monochrome image printing, respectively. In this embodiment, the tension form of the intermediate transfer belt 101 is changed during print standby (when the intermediate transfer unit 100 is attached to or detached from the device main body 2), during color image printing, and during monochrome image (black monochromatic image) printing, as shown in FIGS. 4(a), (b), and (c). The intermediate transfer unit 100 has bearing members 201a to 201f that rotatably support the primary transfer rollers 106Y, 106M, 106C, and 106K, and the first and second auxiliary rollers 103 and 104, respectively. Each of the bearing members 201a to 201f is supported by the unit frame 107 so that each roller can be moved toward and away from the photosensitive member tangential plane PL. The photosensitive member tangential plane PL is a common tangential plane of the multiple photosensitive drums 11Y, 11M, 11C, and 11K on the side that contacts the intermediate transfer belt 101. The intermediate transfer unit 100 also has a movement mechanism (contact / separation mechanism) 202 that moves each of the bearing members 201a to 201f.

[0045] As shown in FIG. 4(a), the movement mechanism 202 disposes the bearing members 201a to 201f so that all the primary transfer rollers 106Y, 106M, 106C, and 106K and the first and second auxiliary rollers 103 and 104 are disposed at a second position (separated position) farther from the photosensitive drum tangential plane PL than the first position described later during printing standby (when the intermediate transfer unit 100 is attached to or detached from the device body 2). As a result, the intermediate transfer belt 101 is separated from all the photosensitive drums 11Y, 11M, 11C, and 11K. That is, when the intermediate transfer unit 100 is attached to or detached from the device body 2, a space is provided between the photosensitive drums 11Y, 11M, 11C, and 11K and the intermediate transfer belt 101 so that they can be attached and detached without rubbing against each other. The intermediate transfer unit 100 is attached to or detached from the device body 2 by being moved in a direction along the photosensitive drum tangential plane PL (approximately parallel in this embodiment). As shown in FIG. 4B, the movement mechanism 202 disposes the bearing members 201a-201f so that all the primary transfer rollers 106Y, 106M, 106C, 106K and the first and second auxiliary rollers 103, 104 are disposed at a first position (contact position) closer to the photosensitive drum tangent plane PL than the second position described above during color image printing. This allows the intermediate transfer belt 101 to contact all the photosensitive drums 11Y, 11M, 11C, 11K. As shown in FIG. 4C, the movement mechanism 202 disposes the bearing members 201a-201f so that the primary transfer rollers 106Y, 106M, 106C and the second auxiliary roller 104 for yellow, magenta, and cyan are disposed at the second position (separated position) described above, and the primary transfer roller 106K and the first auxiliary roller 103 for black are disposed at the first position (contact position) described above during monochrome image printing. As a result, the intermediate transfer belt 101 comes into contact with only the black photosensitive drum 11K among the four photosensitive drums 11Y, 11M, 11C, and 11K.

[0046] 3. Overview of Control in this Example In this embodiment, the intermediate transfer belt 101 has a shorter life than the device main body 2. Therefore, the intermediate transfer belt 101 can be replaced with a new one by making the intermediate transfer unit 100 detachable from the device main body 2. In this embodiment, the belt cleaning device 108, and in particular, the cleaning blade 181, are set to have a life that is approximately the same as the life of the intermediate transfer belt 101. Therefore, in this embodiment, it is assumed that the intermediate transfer unit 100, which is normally an integrated intermediate transfer unit 100 including the belt cleaning device 108 and the belt conveying section 109 (including the intermediate transfer belt 101), is replaced as a whole. However, as described above, depending on the recording material P used, the difference in life between the intermediate transfer belt 101 and the belt cleaning device 108 may become large. This may cause toner to accidentally slip through the cleaning blade 181. Therefore, in this embodiment, the belt cleaning device 108 can be replaced with a new one by making it detachable from the belt conveying section 109 of the intermediate transfer unit 100. In this manner, in this embodiment, in the intermediate transfer unit 100, the belt cleaning device 108 is further detachable from the belt conveying section 109. As a result, even if the belt cleaning device 108 in the intermediate transfer unit 100 breaks down, it is possible to continue using the intermediate transfer belt 101 by replacing only the belt cleaning device 108. Therefore, by making it possible to replace only the minimum necessary components, it is possible to suppress an increase in the running costs of the image forming apparatus 1.

[0047] Here, in consideration of general operation, it is preferable that the image forming apparatus is configured to display information on the total usage of the intermediate transfer unit including the cleaning device and the intermediate transfer belt (belt conveying section) as a guide for when to replace the intermediate transfer unit. For example, information on the usage such as the remaining life value of the entire intermediate transfer unit can be displayed. However, in such a configuration, if the operator is configured to input information indicating that the replacement unit has been replaced as in the conventional case, for example, when only the belt cleaning device is replaced, the operator may erroneously input information indicating that the intermediate transfer belt has been replaced. In such a case, for example, a problem may occur such as not being able to properly display information on the usage of the intermediate transfer unit corresponding to the usage of the intermediate transfer belt.

[0048] Therefore, in this embodiment, the belt cleaning device 108 of the intermediate transfer unit 100 is provided with a memory holder (memory holding unit) 4 as a support member having a memory board 4a as a storage unit constituting a storage means. Then, information indicating whether the belt cleaning device 108 is new or not (hereinafter, also simply referred to as "old / new information") is recorded on the memory board 4a. Also, information indicating whether the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) are shipped as an integrated intermediate transfer unit 100 or whether the belt cleaning device 108 is shipped as a single unit (hereinafter, also simply referred to as "unit configuration information") is recorded on the memory board 4a. Also, the "unit configuration information" may indirectly determine whether "the belt cleaning device 108 is shipped as a single unit" by using both the above-mentioned "old / new information" and information indicating whether the intermediate transfer belt 101 attached to the intermediate transfer unit 100 is new or not. That is, the memory board 4a may store information indicating whether the intermediate transfer belt 101 attached to the intermediate transfer unit 100 is new or not, as information for acquiring unit configuration information.

[0049] In addition, in this embodiment, the device main body 2 is provided with a connection part (contact spring holding member, contact holder) 5 equipped with a contact spring 5a for electrically connecting with the memory board 4a provided in the belt cleaning device 108 in order to read the information recorded on the memory board 4a provided in the belt cleaning device 108.

[0050] The memory holder 4 constitutes a support member that supports the memory board 4a having the memory contacts 4b that are electrical connection parts. The connection part 5 holds the contact springs 5a that are electrical connection parts that can come into contact with the memory contacts 4b, and constitutes an engagement member that can engage with the memory holder 4.

[0051] In this embodiment, the memory holder 4 is provided on the outer surface of the cleaning container 184 in the belt cleaning device 108, on the side located at the tip in the mounting direction (insertion direction) of the intermediate transfer unit 100 to the device body 2. On the other hand, the connection part 5 is fixed to a frame (not shown) in the device body 2. As shown in FIG. 2, the connection part 5 is provided at a position where the memory contact 4b of the memory board 4a and the contact spring 5a are in conductive contact with each other in a state where the intermediate transfer unit 100 is mounted on the device body 2. The contact springs 5a, 5a are connected to a detection circuit 6 (FIG. 6) provided in the device body 2 via an electric cable (not shown) provided in the device body 2. The detection circuit 6 is composed of a read / write circuit as a read / write part. And the detection circuit (read / write circuit) 6 as a detection part constituting the detection means is capable of detecting (reading) the new / old information and the unit configuration information from the memory board 4a as a detected part via the contact spring 5a and the memory contact 4b.

[0052] This makes it possible to prevent malfunctions caused by an operator forgetting to input information indicating that the entire intermediate transfer unit 100 has been replaced with a new one, or by an operator erroneously inputting information indicating that only the belt cleaning device 108 has been replaced with a new one in this case. Also, it makes it possible to prevent malfunctions caused by an operator forgetting to input information indicating that the entire intermediate transfer unit 100 has been replaced in this case, or by an operator erroneously inputting information indicating that only the belt cleaning device 108 has been replaced with a new one in this case.

[0053] As described above, when the difference in life span between the intermediate transfer belt 101 and the belt cleaning device 108 becomes large due to factors such as the recording material P used, the belt cleaning device 108 is more susceptible to the effects of the recording material P and often has a shorter life span. For this reason, by providing the memory board 4a to the belt cleaning device 108 out of the belt cleaning device 108 and the belt conveying section 109, good results can be obtained while achieving size reduction and cost reduction.

[0054] 4. Replacement timing In this embodiment, the image forming apparatus 1 is capable of providing (notifying) the operator of the cumulative index value relating to the amount of usage of the intermediate transfer unit 100 since the start of use (when it was new) as a guide for when to replace the intermediate transfer unit 100.

[0055] In this embodiment, the accumulated values ​​of the index values ​​relating to the amount of usage since the start of use (when new) of the belt cleaning device 108 and the intermediate transfer belt 101 are counted separately, and the larger accumulated value is set as the accumulated value of the index value relating to the amount of usage since the start of use (when new) of the intermediate transfer unit 100. Then, this accumulated value of the index value relating to the amount of usage since the start of use (when new) of the intermediate transfer unit 100 can be provided (notified) to the operator as a guide for when to replace the intermediate transfer unit 100.

[0056] That is, in this embodiment, the image forming apparatus 1 is provided with a cleaning counter 71 (FIG. 6) configured with a storage unit as a counting means (counting unit) that counts an index value related to the amount of use of the belt cleaning device 108 since the start of use and stores the count value (count value). Also, in this embodiment, the image forming apparatus 1 is provided with a belt counter 72 (FIG. 6) configured with a storage unit as a counting means (counting unit) that counts an index value related to the amount of use of the intermediate transfer belt 101 since the start of use and stores the count value (count value). In this embodiment, the number of prints (the number of recording materials P on which images are formed) converted to a predetermined size is used as the index value related to the amount of use of the belt cleaning device 108 since the start of use. Also, in this embodiment, the number of prints (the number of recording materials P on which images are formed) converted to a predetermined size is used as the index value related to the amount of use of the intermediate transfer belt 101 since the start of use. However, these index values ​​may be values ​​that correlate with the usage of the belt cleaning device 108 and the intermediate transfer belt 101 accompanying the operation of the image forming apparatus 1. For example, the printing time, the transport distance (or the number of rotations) and the transport time (or the rotation time) of the intermediate transfer belt 101 may be used. In this embodiment, the image forming apparatus 1 is provided with an intermediate transfer unit counter 73 (FIG. 6) that is configured as a memory unit serving as a counting means (counting unit) and that stores the larger of the count value of the cleaning counter 71 and the count value of the belt counter 72 as an index value relating to the usage amount of the intermediate transfer unit 100 since the start of use. In this embodiment, the count value of the intermediate transfer unit counter 73 is provided (notified) to the operator as a guide for the replacement time.

[0057] In this embodiment, the control unit 50 (FIG. 6) of the image forming apparatus 1 updates (increments) and stores the count values ​​(number of prints) of the cleaning counter 71 and the belt counter 72, which are storage units, each time an image is formed on the recording material P. Also, in this embodiment, when the control unit 50 detects that the belt cleaning device 108 is new and detects (determines) that the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were shipped together, it resets the count values ​​(number of prints) of the cleaning counter 71 and the count values ​​(number of prints) of the belt counter 72 to their initial values ​​(zero in this embodiment).

[0058] In addition, in this embodiment, when the control unit 50 detects that the belt cleaning device 108 is new and detects (determines) that the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were not shipped together (i.e., the belt cleaning device 108 was shipped alone), it resets the count value (number of printed sheets) of the cleaning counter 71 to an initial value (zero in this embodiment) and does not reset the count value (number of printed sheets) of the belt counter 72.

[0059] In this embodiment, the control unit 50 can display the count value of the intermediate transfer unit counter 73 on the operation unit 60 in response to a predetermined operation by the operator on the operation unit 60. As described above, the displayed count value of the intermediate transfer unit counter 73 is the larger of the count value of the cleaning counter 71 and the count value of the belt counter 72. This allows the operator to check the count value of the intermediate transfer unit counter 73 on the operation unit 60 as appropriate. If a problem such as image staining due to poor cleaning occurs, the operator can replace the belt cleaning device 108 with a new one. In addition, the operator can check the intermediate transfer unit counter 73 and replace the entire intermediate transfer unit 100 with a new one if the count value exceeds a predetermined life value set in advance. In this embodiment, the estimated life of the belt cleaning device 108, the intermediate transfer belt 101, and the intermediate transfer unit 100 is set to 600,000 printed sheets.

[0060] As a result, even if only the belt cleaning device 108 is replaced before the end of the life of the intermediate transfer unit 100 due to a problem such as image stains caused by poor cleaning, the user can use the remaining life of the intermediate transfer belt 101 that has not been replaced. As a result, an increase in the running costs of the image forming apparatus 1 can be suppressed. Also, for example, when only the belt cleaning device 108 is replaced, it is possible to prevent the operator from erroneously resetting the belt counter 72. As a result, it is possible to prevent the intermediate transfer belt 101 from being used beyond its life.

[0061] The image forming apparatus 1 may automatically notify (display, etc.) information encouraging replacement of the intermediate transfer unit 100 on the operation unit 60 (or a display unit of an external device) based on the intermediate transfer unit counter 73. For example, the control unit 50 can compare the intermediate transfer unit counter 73 with a preset threshold value indicating the life of the intermediate transfer unit 100, and notify the operation unit 60, etc. of the above information when it determines that the count value has exceeded the threshold value.

[0062] In addition, the operations and notifications (displays, etc.) of information that are performed by the operation unit 60 in this embodiment can also be performed by an external device such as a personal computer connected to the image forming apparatus 1, in addition to or instead of this.

[0063] Furthermore, the notification of information is not limited to being by display, but may be by light emitted by a light-emitting element, such as turning on or blinking a warning light, or by sound emitted by a sound-producing element, such as emitting a warning sound.

[0064] In addition, the control unit 50 may be configured to display the count value of the cleaning counter 71 and the count value of the belt counter 72 on the operation unit 60 or an external device, respectively, in response to a predetermined operation by the operator, for example.

[0065] Furthermore, the count value of at least one of the cleaning counter 71, the belt counter 72, and the intermediate transfer unit 73 may be stored in the memory board 4a provided in the belt cleaning device .

[0066] 5. Control Configuration FIG. 6 is a schematic block diagram showing the control configuration of the main parts of the image forming apparatus 1 of this embodiment. The image forming apparatus 1 is provided with a control unit (control circuit) 50 constituting a control means. The control unit 50 is configured to have a CPU 51 as an arithmetic processing unit (arithmetic processing circuit) constituting an arithmetic processing means which is a central element for performing arithmetic processing, a memory (storage medium) 52 such as a ROM or RAM as a storage unit constituting a storage means, an interface unit (input / output circuit) (not shown), and the like. The RAM, which is a rewritable memory, stores information input to the control unit 50, detected information, arithmetic results, and the like, and the ROM stores a control program, a data table obtained in advance, and the like. The CPU 51 and the memory 52 are capable of transferring and reading data to and from each other. The interface unit controls the input / output (communication) of signals between the control unit 50 and devices connected thereto.

[0067] The control unit 50 is connected to each part of the image forming apparatus 1 (image forming unit S, driving devices for members related to the conveyance of the intermediate transfer belt 101 and recording material P, various power sources, various sensors, etc.). In relation to this embodiment, the control unit 50 is connected to a cleaning counter 71, a belt counter 72, and an intermediate transfer unit counter 73. The control unit 50 is also connected to a detection circuit 6 for detecting whether the belt cleaning device 108 is new or not (new / old information) and whether the belt cleaning device 108 and the belt conveyance unit 109 (including the intermediate transfer belt 101) were shipped as a unit or not (unit configuration information). The detection circuit 6 is composed of a read / write circuit as a read / write unit capable of reading information from the memory board 4a provided in the belt cleaning device 108 and writing information to the memory board 4a. The detection circuit 6 is connected to a contact spring 5a held by a connection unit 5 that can be electrically connected to a memory contact 4b of the memory board 4a. The detection circuit 6 inputs information read from the memory board 4a to the control unit 50 via the contact spring 5a and the memory contact 4b. The detection circuit 6 writes information to the memory board 4a via the contact spring 5a and the memory contact 4b under the control of the control unit 50. The memory contact 4b and the contact spring 5a are connected to each other, so that the detection circuit 6 can read and write information from and to the memory board 4a. The control unit 50 is also connected to an operation unit (operation panel, operation screen) 60 provided in the image forming apparatus 1. The operation unit 60 has a display unit (display means) that displays information under the control of the control unit 50, and an input unit (input means) that inputs information to the control unit 50 by operation by an operator such as a user or a service representative. The operation unit 60 may be configured to have a touch panel having the functions of the display means and the input means. The control unit 50 may also be connected to an image reading device (not shown) provided in the image forming apparatus 1 or connected to the image forming apparatus 1, or an external device (not shown) such as a personal computer connected to the image forming apparatus 1.

[0068] Thus, in this embodiment, the intermediate transfer unit 100 is provided with a memory holder 4 having a memory substrate 4a, and the device body 2 is provided with a connection section 5 having a contact spring 5a for reading information from the memory substrate 4a. The memory substrate 4a stores at least information on whether the belt cleaning device 108 is new or not ("new / old information"), and information on whether the belt cleaning device 108 and the belt conveying section 109 (including the intermediate transfer belt 101) were shipped as a unit ("unit configuration information"). The memory substrate 4a may also store information on characteristic values ​​of elements that configure the intermediate transfer unit 100.

[0069] The control unit 50 can detect whether the belt cleaning device 108 is new or not based on information from the memory board 4a (including the absence of predetermined information). The control unit 50 can determine whether the belt cleaning device 108 is new or not by, for example, acquiring predetermined information stored in a predetermined storage area in the memory board 4a or detecting the presence or absence of predetermined information in the predetermined storage area. For example, the control unit 50 can determine that the belt cleaning device 108 is new by acquiring information indicating that the belt cleaning device 108 is new from the memory board 4a. This information is recorded in the memory board 4a during the production process of the intermediate transfer unit 100 or the belt cleaning device 108, at the time of shipment from the factory, or the like. In this case, when the use of the belt cleaning device 108 is started, the information may be erased or updated to information indicating that it is not new. Also, the control unit 50 can determine that the belt cleaning device 108 is not new by acquiring information indicating that the belt cleaning device 108 is not new (use has started) from the memory board 4a. In this case, when use of the belt cleaning device 108 begins, information indicating that the belt cleaning device 108 is not new may be written, or the information indicating that the belt cleaning device 108 is new may be rewritten to information indicating that the belt cleaning device is not new.

[0070] Furthermore, the control unit 50 can detect (determine) whether the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were shipped as a unit based on information (including the absence of predetermined information) from the memory substrate 4a. The control unit 50 can determine whether the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were shipped as a unit by, for example, acquiring predetermined information stored in a predetermined storage area in the memory substrate 4a or detecting the presence or absence of predetermined information in the predetermined storage area. This information is recorded in the memory substrate 4a during the production process of the intermediate transfer unit 100 or the belt cleaning device 108, at the time of shipment from the factory, etc.

[0071] The image forming apparatus 1 executes a job, which is a series of operations that starts with one start instruction and forms and outputs an image on one or multiple recording materials P. A job generally includes an image forming process (image forming operation, print operation, printing operation), a pre-rotation process, a paper-interval process when forming images on multiple recording materials P, and a post-rotation process. The image forming process is a period during which electrostatic image formation, toner image formation, primary transfer of the toner image, and secondary transfer of the toner image are performed for an image that is actually formed on the recording material P and output, and the image formation time (image formation period) refers to this period. More specifically, the timing of the image formation time differs depending on the position where each of the electrostatic image formation, toner image formation, primary transfer of the toner image, and secondary transfer is performed. The pre-rotation process is a period during which a preparatory operation is performed before the image forming process from when a start instruction is input until the image formation actually starts. The paper-interval process is a period corresponding to the period between recording materials P when image formation is performed continuously on multiple recording materials P (continuous image formation). The post-rotation process is a period in which a tidying operation (preparatory operation) is performed after the image forming process. The non-image forming time (non-image forming period) is a period other than the image forming time, and includes the above-mentioned pre-rotation process, the sheet interval process, the post-rotation process, and further the pre-multiple rotation process which is a preparatory operation when the image forming apparatus 1 is turned on or when it returns from a sleep state.

[0072] The control unit 50 controls each unit of the image forming apparatus 1 based on job information to perform an image forming operation. The job information includes a start instruction (start signal) input from the operation unit 60 or an external device, information (command signal) on image forming conditions such as the type of recording material P, and image information (image signal) input from the image reading device or an external device.

[0073] 6. Control Procedure Next, the process when the intermediate transfer unit 100 in this embodiment is attached to the apparatus main body 2 will be further described.

[0074] When replacing the belt cleaning device 108, as shown in FIG. 2 and FIG. 5, the operator removes the intermediate transfer unit 100 with the belt cleaning device 108 attached from the device body 2 as a whole. Then, the operator further removes only the belt cleaning device 108 from the belt conveying section 109 of the removed intermediate transfer unit 100. After that, the operator attaches a new belt cleaning device 108 to the belt conveying section 109. Then, the operator inserts the intermediate transfer unit 100 with the new belt cleaning device 108 attached as a whole into the device body 2. When the intermediate transfer unit 100 is inserted into the device body 2, the intermediate transfer unit 100 reaches a predetermined position in the device body 2 as shown in FIG. 1. Then, the memory board 4a of the memory holder 4 provided in the belt cleaning device 108 and the connection section 5 provided in the device body 2 are electrically connected by contacting the memory contact 4b of the memory board 4a and the contact spring 5a of the connection section 5. The operation for replacing the entire intermediate transfer unit 100 is the same as that described above, except that the belt cleaning device 108 is not attached to or detached from the belt conveying section 109, and a new intermediate transfer unit 100 is attached to the apparatus body 2. In this embodiment, the image forming apparatus 1 is configured so that the power of the image forming apparatus 1 is turned off when the intermediate transfer unit 100 is removed from the apparatus body 2. At this time, the power of the image forming apparatus 1 may be turned off by an operator operating a power switch, or may be turned off by the control unit 50 or the like based on the detection by an opening / closing sensor (not shown) that the right door unit 3 has been opened.

[0075] 7 is a flow chart showing an outline of the procedure of processing when the intermediate transfer unit 100 is attached to the apparatus main body 2. The processing procedure in this embodiment will be described with reference to FIG.

[0076] When the intermediate transfer unit 100 is attached to the apparatus main body 2 and the power supply of the image forming apparatus 1 is turned on (S101), the control unit 50 checks (reads) the information on the memory board 4a by the detection circuit 6 at a predetermined timing before the first printing operation is performed (S102). At this time, the power supply of the image forming apparatus 1 may be turned on by an operator operating a power switch, or may be turned on by the control unit 50 or the like based on the detection of the right door unit 3 being closed by an open / close sensor (not shown). The control unit 50 reads the new / old information in the information acquired from the memory board 4a by the detection circuit 6, and judges whether the belt cleaning device 108 is new or not (S103). If the control unit 50 judges in S103 that the belt cleaning device 108 is new, the control unit 50 next reads the unit configuration information in the information acquired from the memory board 4a by the detection circuit 6, and judges whether the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were shipped as a unit (S104).

[0077] Then, when the control unit 50 determines in S104 that the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were not shipped as a unit, it resets the cleaning counter 71 to an initial value (zero in this embodiment) (S105). When it is determined in S103 that the belt cleaning device 108 is new and it is also determined in S104 that the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were not shipped as a unit, it indicates that the belt cleaning device 108 is new but the belt conveying unit 109 (intermediate transfer belt 101) is not new. After that, the control unit 50 puts the image forming apparatus 1 into a standby state to wait for a job (S106).

[0078] Furthermore, if the control unit 50 determines in S104 that the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were shipped as a unit, it resets the cleaning counter 71 and the belt counter 72 to their initial values ​​(zero in this embodiment) (S107). If the control unit 50 determines in S103 that the belt cleaning device 108 is new and determines in S104 that the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were shipped as a unit, it indicates that both the belt cleaning device 108 and the belt conveying unit 109 (intermediate transfer belt 101) are new. Thereafter, the control unit 50 sets the image forming apparatus 1 to a standby state in which it waits for a job (S106).

[0079] Furthermore, if the control unit 50 determines in S103 that the belt cleaning device 108 is not new, the process proceeds to S106. If the control unit 50 determines in S103 that the belt cleaning device 108 is not new, this indicates that both the belt cleaning device 108 and the belt conveying unit 109 (intermediate transfer belt 101) are not new.

[0080] 7.Effects Thus, in this embodiment, the image forming apparatus 1 has a rotatable image carrier (photosensitive drum) 11 that carries a toner image, and an intermediate transfer unit 100 for transferring the toner image formed on the image carrier 11 to a recording material P, the intermediate transfer unit 100 including a circumferentially movable intermediate transfer body (intermediate transfer belt) 101 that transports the toner image primarily transferred from the image carrier 11 to the recording material P for secondary transfer, and a cleaning device (belt cleaning device) 108 that cleans the intermediate transfer body 101. In this embodiment, the image forming apparatus 1 has the intermediate transfer unit 100 detachable from the apparatus main body 2 of the image forming apparatus 1, and the cleaning device 108 detachable from the unit main body 109 (belt conveying section) of the intermediate transfer unit 100. The cleaning device 108 is provided with a memory section (memory board) 4a which is detachable from the unit main body 109 together with the cleaning device 108. The apparatus main body 2 is provided with a control section 50 capable of reading information from the memory section 4a. The control section 50 is capable of reading, from the memory section 4a, first information (old / new information) regarding whether the cleaning device 108 is new or not, and, when an intermediate transfer unit 100 equipped with a new cleaning device 108 is installed, second information (unit configuration information) regarding whether the intermediate transfer body 101 installed in the intermediate transfer unit 100 is new or not.In this embodiment, the image forming apparatus 1 has a first counting means (cleaning counter) 71 that counts an index value relating to the amount of use of the cleaning device 108 from when it was new, and a second counting means (belt counter) 72 that counts an index value relating to the amount of use of the intermediate transfer body 101 from when it was new, and when the intermediate transfer unit 100 is attached to the apparatus main body 2, the control unit 50 detects whether or not the cleaning device 108 is new and whether or not the intermediate transfer body 101 is new. (b) when the first information indicates that the cleaning device 108 is new and the second information indicates that the intermediate transfer body 101 attached to the intermediate transfer unit 100 is new, the control unit 50 performs control so as to reset the count value by the first counting means 71 to the initial value and not to reset the count value by the second counting means 72 to the initial value. Also, in this embodiment, the control unit 50 performs control so as to execute a process for notifying information regarding the usage amount of the intermediate transfer unit 100 based on the count value by the first counting means 71 and the count value by the second counting means 72. In particular, in this embodiment, the control unit 50 controls the execution of a process for notifying information regarding the usage amount of the intermediate transfer unit 100 based on the larger of the counting value by the first counting means 71 and the counting value by the second counting means 72.

[0081] As described above, according to this embodiment, only the belt cleaning device 108 can be replaced in the intermediate transfer unit 100. Therefore, the intermediate transfer belt 101 in a usable state can be used continuously, and it is possible to suppress an increase in the running cost of the image forming apparatus 1. Furthermore, according to this embodiment, it is possible to automatically detect on the device main body 2 side whether the belt cleaning device 108 and the belt conveying section 109 (including the intermediate transfer belt 101) have been replaced as a whole. Therefore, it is possible to reduce the time and effort required for maintenance without requiring the operator to perform a special operation such as inputting information indicating that the intermediate transfer unit 100 has been replaced. Furthermore, according to this embodiment, it is possible to prevent the operator from erroneously resetting the belt counter 72 when only the belt cleaning device 108 has been replaced. Therefore, it is possible to provide (notify) the operator of an appropriate guide for the replacement time of the intermediate transfer unit 100 as the count value of the intermediate transfer unit counter 73, and it is possible to prevent the intermediate transfer belt 101 from being used beyond its lifespan.

[0082] [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 given the same reference numerals as those of embodiment 1, and detailed explanations are omitted.

[0083] 1. Overview of this embodiment In this embodiment, the image forming apparatus 1 executes a predetermined initial control when the belt cleaning device 108 or the intermediate transfer unit 100 is replaced with a new one.

[0084] The cleaning blade 181 has an edge portion at its free end in contact with the intermediate transfer belt 101. The cleaning blade 181 is made of an elastic body, but depending on the recording material P used, etc., the difference in life span between the intermediate transfer belt 101 and the belt cleaning device 108 may become large. In such a case, the belt cleaning device 108 is more susceptible to the influence of the recording material P and often has a shorter life span. Therefore, an operator such as a user or a service person can check the stains on the image and replace the belt cleaning device 108 as described above. In this embodiment, when the control unit 50 of the image forming apparatus 1 detects that the belt cleaning device 108 has been replaced with a new one based on a signal from the detection circuit 6, the control unit 50 controls the image forming apparatus 1 to execute a predetermined initial control.

[0085] In this embodiment, the control unit 50 executes, as the initial control, a supply control (supply operation) that is a control for supplying toner as a lubricant to the contact portion between the cleaning blade 181 and the intermediate transfer belt 101. Here, the supply operation executed as the initial control is also referred to as "initial supply control." This is because the frictional force acting on the contact portion between the cleaning blade 181 and the intermediate transfer belt 101 may be greater when the cleaning blade 181 is new than when it is not new. If the frictional force acting on the contact portion between the new cleaning blade 181 and the intermediate transfer belt 101 becomes excessively large, there is a possibility that a defect such as the cleaning blade 181 turning over may occur.

[0086] In this embodiment, the initial supply control is performed as follows. When the control unit 50 detects that a new belt cleaning device 108 has been attached to the apparatus main body 2, the control unit 50 performs the initial supply control to supply toner to the contact portion between the cleaning blade 181 and the intermediate transfer belt 101 before the first printing operation is performed. In the initial supply control, a predetermined toner image in the form of a belt or line extending along a direction (main scanning direction) substantially perpendicular to the moving direction of the surface of the photosensitive drum 11 (and the intermediate transfer belt 101) is formed on the photosensitive drum 11 in at least one of the multiple image forming units S. Here, this predetermined toner image is also referred to as a "supply toner image". In this embodiment, the supply toner image is formed through a charging process, an exposure process, and a development process in the same process as that during normal image formation described above. The supply toner image formed on the photosensitive drum 11 is transferred onto the intermediate transfer belt 101 at the primary transfer unit T1. The supply toner image transferred onto the intermediate transfer belt 101 is supplied to the contact portion between the cleaning blade 181 and the intermediate transfer belt 101 by the rotation of the intermediate transfer belt 101. When the supply toner image passes through the secondary transfer portion T2, a voltage of the same polarity as the normal charging polarity of the toner (opposite polarity to that during secondary transfer) is applied to the secondary transfer outer roller 16, so that the supply toner image is prevented from adhering to the secondary transfer outer roller 16. Alternatively, a means for separating the secondary transfer outer roller 16 from the intermediate transfer belt 101 when the supply toner image passes through the secondary transfer portion T2 may be provided. In this embodiment, the supply toner image is a belt-like or line-like toner image that covers substantially the entire image forming area (area that can bear a toner image) in a direction (width direction) substantially perpendicular to the moving direction of the surface of the photosensitive drum 11 (and the intermediate transfer belt 101). However, this toner image may be a single toner image or multiple toner images formed with any length in a direction substantially perpendicular to the moving direction of the surface of the photosensitive drum 11 (and intermediate transfer belt 101). For example, in this embodiment, the supplied toner image is a belt-shaped black toner image whose length in the substantially perpendicular direction covers substantially the entire image forming area and whose length in the direction substantially parallel to the moving direction of the surface of the photosensitive drum 11 (and intermediate transfer belt 101) (sub-scanning direction) is 10 mm.In this embodiment, the density of the supplied toner image is FFH (the highest density level (solid image) among 256 levels from 0 to 255). By utilizing the lubricity of the toner (or its external additive) supplied to the contact portion between the cleaning blade 181 and the intermediate transfer belt 101 in the initial supply control, the frictional force acting on the contact portion between the cleaning blade 181 and the intermediate transfer belt 101 can be reduced. This makes it possible to suppress the occurrence of problems such as curling up of the cleaning blade 181.

[0087] On the other hand, in this embodiment, when the image forming apparatus 1 starts operating (power supply) with the belt cleaning device 108 that is not new attached to the apparatus body 2, the initial supply control is not executed before the first printing operation thereafter. For example, this applies when the belt cleaning device 108 that is not new is reattached to the apparatus body 2, or when the image forming apparatus 1 is powered on with the belt cleaning device 108 that is not new attached to the apparatus body 2.

[0088] Furthermore, in this embodiment, when the control unit 50 detects that the belt cleaning device 108 is new and detects (determines) that the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were shipped as a unit, the control unit 50 executes, as the initial control, the ATVC control, which is an adjustment control (adjustment operation) for correcting the primary transfer bias, in addition to the above-mentioned initial supply control. In this case, since the intermediate transfer belt 101 has been replaced, this is to obtain information on the electrical resistance of the new intermediate transfer belt 101 after replacement. The ATVC control is the following control. When the non-image portion on the photosensitive drum 11 passes through the primary transfer portion T1, a primary transfer voltage that is constant-current controlled at a predetermined current value set in advance is applied to the primary transfer portion T1 (primary transfer roller 106), and the generated voltage value at that time is detected. This makes it possible to obtain information on the electrical resistance of the intermediate transfer belt 101. During image formation (primary transfer), constant voltage control of the primary transfer voltage is performed at the previously generated voltage value or a voltage value determined based on the result of arithmetic processing of the previously generated voltage value. This makes it possible to suppress memory of the photosensitive drum 11 by, for example, suppressing overcurrent from the primary transfer portion T1 to the photosensitive drum 11 even when the intermediate transfer belt 101 is replaced. At the same time, since an appropriate primary transfer voltage can be applied during image formation (primary transfer), it becomes possible to output a stable and good image.

[0089] In this embodiment, the ATVC control is performed synchronously and individually in each image forming unit S. Alternatively, a primary transfer voltage controlled to a constant voltage at a preset predetermined voltage value may be applied to the primary transfer unit T1 (primary transfer roller 106), and the generated current value may be detected to obtain information regarding the electrical resistance of the intermediate transfer belt 101. In this embodiment, the ATVC control for obtaining information regarding the electrical resistance of the intermediate transfer belt at the primary transfer unit T1 has been described, but a similar ATVC control may be performed at the secondary transfer unit T2 to obtain information regarding the electrical resistance of the intermediate transfer belt (to correct the secondary transfer voltage).

[0090] FIG. 8 is a schematic block diagram showing the control configuration of the main parts of the image forming apparatus 1 of this embodiment. The control configuration shown in FIG. 8 is roughly the same as the control configuration shown in FIG. 6 described in the first embodiment. However, the control configuration shown in FIG. 8 includes a current detection unit (current detection circuit) 81 as a current detection means for detecting the output current value of the primary transfer power supply 80, and a voltage detection unit (voltage detection circuit) 82 as a voltage detection means for detecting the output voltage of the primary transfer power supply 80. The current detection unit 81 detects the value of a current flowing through the primary transfer portion T1 (primary transfer roller 106, primary transfer power supply 80) when a voltage is applied to the primary transfer portion T1 (primary transfer roller 106) by the primary transfer power supply 80. The voltage detection unit 82 detects the value of a voltage applied to the primary transfer portion T1 (primary transfer roller 106) by the primary transfer power supply 80 (output by the primary transfer power supply 80). The current detection unit 81 and the voltage detection unit 82 input signals (information) indicating the detection results to the control unit 50. Although not shown in the figure, in this embodiment, the primary transfer power supply 80, the current detection unit 81, and the voltage detection unit 80 are provided independently for each image forming unit S.

[0091] In this embodiment, the control unit 50 executes the above-mentioned initial supply control as initial control during non-image formation when a new belt cleaning device 108 is attached to the apparatus main body 2. Furthermore, in this embodiment, the control unit 50 executes the above-mentioned initial supply control and ATVC control as initial control during non-image formation when a new intermediate transfer unit 100 is entirely attached to the apparatus main body 2.

[0092] Thus, in this embodiment, the image forming apparatus 1 performs a predetermined initial control when the belt cleaning device 108 or the intermediate transfer unit 100 is replaced with a new one. At this time, if the operator inputs information indicating that the replacement unit has been replaced as in the conventional configuration, the operator may forget to input the information when only the belt cleaning device 108 is replaced in the intermediate transfer unit 100. In that case, the initial control that needs to be performed when the belt cleaning device 108 is replaced with a new one may not be performed correctly, which may cause problems such as turning over of the cleaning blade 181. Also, when only the belt cleaning device 108 is replaced, information indicating that the intermediate transfer unit 100 has been replaced may be erroneously input. In that case, the initial control that needs to be performed when the intermediate transfer belt 101 is replaced may be performed in vain, which may cause problems such as an increase in downtime.

[0093] 2. Control Procedure 9 is a flow chart showing an outline of the procedure of processing when the intermediate transfer unit 100 in this embodiment is attached to the apparatus main body 2. The processing procedure in this embodiment will be described with reference to FIG.

[0094] When the intermediate transfer unit 100 is attached to the apparatus main body 2 and the power supply of the image forming apparatus 1 is turned ON (S201), the control unit 50 checks (reads) the information on the memory board 4a by the detection circuit 6 at a predetermined timing before the first printing operation (S202). The control unit 50 reads the new / old information in the information acquired from the memory board 4a by the detection circuit 6, and judges whether the belt cleaning device 108 is new or not (S203). If the control unit 50 judges in S203 that the belt cleaning device 108 is new, it next reads the unit configuration information in the information acquired from the memory board 4a by the detection circuit 6, and judges whether the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were shipped as a unit (S204).

[0095] Then, when the control unit 50 determines in S204 that the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were not shipped as a unit, it resets the cleaning counter 71 to an initial value (zero in this embodiment) (S205). The control unit 50 also executes the above-mentioned initial supply control as the initial control (S206). Thereafter, the control unit 50 puts the image forming apparatus 1 into a standby state to wait for a job (S207).

[0096] Furthermore, when the control unit 50 determines in S204 that the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were shipped as a single unit, it resets the cleaning counter 71 and the belt counter 72 to their initial values ​​(zero in this embodiment) (S208). Furthermore, the control unit 50 executes the above-mentioned initial supply control as the initial control, and then executes the above-mentioned ATVC control as the initial control (S209). Thereafter, the control unit 50 puts the image forming apparatus 1 into a standby state to wait for a job (S207).

[0097] Moreover, if the control unit 50 determines in S203 that the belt cleaning device 108 is not new, the process proceeds to S207.

[0098] 3.Effects Thus, in this embodiment, when the intermediate transfer unit 100 is attached to the apparatus main body 2, the control unit 50 performs control based on the first information (old / new information) and the second information (unit configuration information) to execute a predetermined control before forming the first image using the intermediate transfer unit 100. In this embodiment, when the intermediate transfer unit 100 is attached to the apparatus main body 2, if the first information indicates that the cleaning device 108 is new, the control unit 50 performs control to supply a predetermined toner image transferred from the image carrier 11 to the intermediate transfer body 101 to a contact portion between the cleaning member 181 provided in the cleaning device 108 and the surface of the intermediate transfer body 101, as the predetermined control. In this embodiment, when the intermediate transfer unit 100 is attached to the apparatus main body 2, (a) if the first information indicates that the cleaning device 108 is new and the second information indicates that the intermediate transfer body 101 attached to the intermediate transfer unit 100 is not new, the control unit 50 executes a predetermined first control before forming a first image using the intermediate transfer unit 100, and (b) if the first information indicates that the cleaning device 108 is new and the second information indicates that the intermediate transfer body 101 attached to the intermediate transfer unit 100 is new, the control unit 50 executes a predetermined second control before forming a first image using the intermediate transfer unit 100. In this embodiment, the first control is a control to supply a predetermined toner image transferred from the image carrier 11 to the intermediate transfer body 101 to a contact portion between a cleaning member 181 provided in the cleaning device 108 and the surface of the intermediate transfer body 101. In this embodiment, the second control is a control for applying a voltage to the intermediate transfer body 101 to obtain information on the electrical resistance of the intermediate transfer body 101. In this embodiment, when the control unit 50 executes the second control, the control unit 50 also executes the first control.

[0099] As described above, according to this embodiment, the apparatus main body 2 can automatically detect that the belt cleaning device 108 has been replaced with a new one. Therefore, the operator does not need to perform a special operation such as inputting information indicating that the belt cleaning device 108 has been replaced. Therefore, it is possible to prevent the initial control required when the belt cleaning device 108 is replaced from not being performed properly due to the operator forgetting to input information. It is also possible to reduce the time and effort required for maintenance. Furthermore, according to this embodiment, the apparatus main body 2 can automatically detect whether the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) have been replaced as a whole. Therefore, it is possible to automatically perform the initial control required when the intermediate transfer belt 101 is replaced. Furthermore, according to this embodiment, it is possible to prevent the operator from erroneously resetting the belt counter 72 when only the belt cleaning device 108 is replaced. Therefore, it is possible to prevent the initial control required when the intermediate transfer belt 101 is replaced from being performed in vain.

[0100] [Example 3] 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 given the same reference numerals as those of embodiment 1, and detailed explanations are omitted.

[0101] 1. Horizontal stripe image defect When the intermediate transfer belt 101 and the belt cleaning device 108 in this embodiment are used, if a certain number of images are output, particularly in a high-temperature environment, and then the image is formed again after being left for a certain period of time, horizontal stripe-like image defects (in the main scanning direction) may occur. As a result of extensive research by the present inventors, it is believed that the horizontal stripe-like image defects occur due to the following mechanism.

[0102] FIG. 10 is a schematic diagram for explaining the mechanism of occurrence of horizontal stripe-like image defects. First, as shown in FIG. 10(a), the components of the surface layer of the intermediate transfer belt 101 are activated especially in a high temperature environment and exude onto the surface of the intermediate transfer belt 101. Next, as shown in FIG. 10(b), the cleaning blade 181 of the belt cleaning device 108 scrapes up the exuded components (herein also referred to as "exuded components"). Then, if left in that state for a certain period of time, as shown in FIG. 10(c), the exuded components are fixed and cannot be scraped off by the cleaning blade 181, and pass through the cleaning portion CL, which is the contact portion between the cleaning blade 181 and the intermediate transfer belt 101. In this way, the exuded components fixed on the intermediate transfer belt 101 reach the contact portion (primary transfer portion) T1 between the photosensitive drum 11 and the intermediate transfer belt 101 during the next image formation, as shown in FIG. 10(d) and FIG. 10(e). Then, as shown in FIG. 10(f), transfer failure of the toner image from the photosensitive drum 11 to the intermediate transfer belt 101 occurs at the portion where the exuded component adheres, resulting in a horizontal streak-like image defect.

[0103] 2. Relationship between horizontal streak-like image defects and temperature As described above, when the temperature of the intermediate transfer belt 101 increases due to an increase in the ambient temperature, the components of the surface layer of the intermediate transfer belt 101 are activated and tend to seep out onto the surface of the intermediate transfer belt 101, which tends to cause image defects in the form of horizontal stripes. The results of an experiment investigating the relationship between the ambient temperature T and the occurrence of image defects in the form of horizontal stripes are shown in Table 1. The occurrence of image defects was confirmed by continuously forming 500 sheets of A4 size paper in an environment of 30° C. using the image forming apparatus 1 having the configuration of this embodiment, and outputting black solid images on 5 sheets of A3 size paper after leaving the image for 1 hour. Here, “◯” indicates that no image defects occurred, and “×” indicates that an image defect occurred. The method of confirming the occurrence of image defects is the same in the experiments that obtained the results in Tables 2 and 3 described later (however, the temperature was changed in the experiment that obtained the results in Table 1).

[0104] [Table 1]

[0105] From Table 1, it can be seen that when the ambient temperature is high, particularly when the ambient temperature is 25° C. or higher, horizontal streak-like image defects are more likely to occur.

[0106] 3. Relationship between horizontal streak-like image defects and intermediate transfer belt usage The occurrence of horizontal streak-like image defects correlates with the usage amount of the intermediate transfer belt 101. Table 2 shows the results of an experiment investigating the relationship between the usage amount of the intermediate transfer belt 101 (count value of the belt counter 72) and the surface roughness of the intermediate transfer belt 101, and the occurrence of horizontal streak-like image defects. The method of confirming the occurrence of image defects was the same as in the experiment that obtained the results in Table 1. Table 2 shows the results at 25°C. Here, the surface roughness of the intermediate transfer belt 101 was measured by measuring the ten-point average roughness Rz (compliant standard: JIS B0601 1994) of the surface of the intermediate transfer belt 101 (the surface that carries the toner image). The ten-point average roughness Rz is calculated by taking a reference length from the roughness curve in the direction of the average line, and measuring from the average line of the taken portion in the direction of the longitudinal magnification, and calculating the sum of the average of the absolute values ​​of the elevations (Yp) of the five highest peaks and the average of the absolute values ​​of the elevations (Yv) of the five lowest valleys, and expressing this value in micrometers (μm). The ten-point average roughness Rz can be measured using a surface roughness measuring instrument, Surfcom (model: 1400D, manufactured by Tokyo Seimitsu) or a measuring instrument that has been correlated with the measuring instrument. The measuring conditions are as follows: Magnification: Vertical 10000, Horizontal 50 Evaluation length: 4mm Measuring head: 2μm (spherical) Feed speed: 0.15mm / sec Cutoff value: 0.8mm Cutoff filter: Gaussian

[0107] [Table 2]

[0108] It can be seen from Table 2 that there is a correlation between the horizontal streak-like image defect and the ten-point mean roughness Rz of the surface of the intermediate transfer belt 101 and the usage amount of the intermediate transfer belt 101 (count value of the belt counter 72). It can also be seen from Table 2 that if the ten-point mean roughness Rz of the surface of the intermediate transfer belt 101 is equal to or greater than a predetermined threshold value, the horizontal streak-like image defect does not occur. In other words, it can be seen that if the usage amount of the intermediate transfer belt 101 (count value of the belt counter 72) is equal to or greater than a predetermined threshold value, the horizontal streak-like image defect does not occur.

[0109] This is believed to be due to the following reason: That is, as the count value of the belt counter 72 of the intermediate transfer belt 101 increases, the surface roughness (ten-point mean roughness Rz) of the intermediate transfer belt 101 increases due to friction with the toner at the contact portion with the belt cleaning device 108 and the photosensitive drum 11. If the surface roughness (ten-point mean roughness Rz) of the intermediate transfer belt 101 is greater than a certain level, the exuded components become more likely to slip through the cleaning unit CL (i.e., are less likely to be scraped up).

[0110] In the image forming apparatus 1 of this embodiment, the relationship that the surface roughness (ten-point average roughness Rz) of the intermediate transfer belt 101 increases with an increase in the count value of the belt counter 72 is substantially always the same. Therefore, the surface roughness (ten-point average roughness Rz) of the intermediate transfer belt 101 and the likelihood of occurrence of horizontal streak-like image defects can be estimated from the count value of the belt counter 72 of the intermediate transfer belt 101.

[0111] 4. Supply control In this embodiment, the image forming apparatus 1 executes a supply control (supply operation) that supplies toner as a lubricant to the contact portion between the cleaning blade 181 and the intermediate transfer belt 101 at a predetermined execution frequency in accordance with the use of the intermediate transfer belt 101. In the supply control, a predetermined belt-shaped toner image ("supply toner image") that extends along a direction (main scanning direction) that is substantially perpendicular to the moving direction of the surface of the photosensitive drum 11 (and the intermediate transfer belt 101) is formed on the photosensitive drum 11 in at least one of the multiple image forming units S. In this embodiment, the supply toner image is formed through a charging process, an exposure process, and a development process in the same process as in the normal image formation described above. The supply toner image formed on the photosensitive drum 11 by this supply control is supplied to the cleaning unit CL that is the contact portion between the cleaning blade 181 and the intermediate transfer belt 101, in the same manner as the supply toner image formed on the photosensitive drum 11 by the initial supply control described in the second embodiment. In this embodiment, in this supply control, a 50 mm black solid image in the circumferential direction of the intermediate transfer belt 101 is supplied to the cleaning unit CL as the supply toner image without being transferred to the recording material S. Also, in this embodiment, this supply toner image has a length that covers almost the entire image forming area (area capable of carrying a toner image) in the longitudinal direction of the photosensitive drum 11 (width direction of the intermediate transfer belt 101). That is, in this embodiment, the supply toner image is a belt-shaped image that extends in the width direction of the intermediate transfer belt 101. This allows toner to be supplied to almost the entire longitudinal area of ​​the cleaning blade 181 of the belt cleaning device 108. Note that the supply toner image formed by this supply control may have other forms, as in the initial supply control described in the second embodiment.

[0112] In this embodiment, the control unit 50 executes the supply control during non-image formation at a predetermined timing (execution frequency) described later. When no image formation is occurring, the supply control can be executed at any timing, such as the pre-multiple rotation process, the pre-rotation process, the sheet interval process, or the post-rotation process. For example, when the supply control is executed during the sheet interval process, the sheet interval (the interval between the preceding recording material P and the next recording material P in the conveying direction of the recording material P) can be increased as necessary to execute the supply control.

[0113] Table 3 shows the results of investigating the relationship between the usage amount of the intermediate transfer belt 101 (count value of the belt counter 72) and the occurrence of horizontal streak-like image defects when the execution frequency of the supply control is changed. In this embodiment, the execution frequency of the supply control is represented by the number of executions per unit number of printed sheets as a predetermined period that correlates with the usage amount of the intermediate transfer belt 101. The method of confirming the occurrence of image defects is the same as the experiment that obtained the results of Tables 1 and 2 above. Table 3 shows the results at 25°C.

[0114] [Table 3]

[0115] From Table 3, it can be seen that the more frequently the supply control is executed, in other words, the more the amount of toner supplied to the cleaning unit CL per predetermined period (unit number of printed sheets in this embodiment) that correlates with the usage amount of the intermediate transfer belt 101, the less likely the image defects are to occur. This is believed to be because, by supplying toner to the cleaning unit CL, the toner and external additives mix with the seeping components, making it difficult for the seeping components to adhere to the intermediate transfer belt 101.

[0116] Also, from Table 3, it can be seen that as the belt counter 72 of the intermediate transfer belt 101 increases, that is, as the surface roughness (ten-point mean roughness Rz) of the intermediate transfer belt 101 increases, the amount of toner supplied to the cleaning unit CL required to suppress horizontal stripe-like image defects decreases. This is thought to be because, as described above, the surface roughness (ten-point mean roughness Rz) of the intermediate transfer belt 101 increases, making it easier for the exuded components to slip through the cleaning unit CL (i.e., harder to scrape up). From Table 3, it can be seen that in the configuration of this embodiment, when the count value of the belt counter 72 is, for example, 50,000 sheets or more, horizontal stripe-like image defects due to the exuded components are unlikely to occur even without executing supply control.

[0117] Therefore, in this embodiment, the control unit 50 controls so as to change the execution frequency of the supply control based on the count value of the belt counter 72. For example, based on the result of Table 3, it is possible to control so as to change the execution frequency of the supply control as shown in Table 4. This makes it possible to suppress an increase in toner consumption and downtime.

[0118] [Table 4]

[0119] Also, as described above, when the ambient temperature is low, horizontal stripe-like image defects due to the seeping component are less likely to occur compared to when the ambient temperature is high. Therefore, the control unit 50 may control to change the execution frequency of the supply control based on the ambient temperature. For example, when the ambient temperature is 25° C. or higher, the supply control is executed at the execution frequency described above. And, when the ambient temperature is less than 25° C., for example, the execution frequency of the supply control in each division of the count value of the belt counter 72 in the above-mentioned case of 25° C. can be made less than that in the above-mentioned case of 25° C. When the ambient temperature is less than 25° C., the supply control may not be executed. FIG. 11 is a schematic block diagram showing the control configuration of the main parts of the image forming apparatus 1 in this case. The control configuration shown in FIG. 11 is roughly the same as the control configuration shown in FIG. 6 described in the first embodiment. However, the control configuration shown in FIG. 11 is provided with an environmental sensor 7 as an environmental detection means. The environmental sensor 7 detects the environment, which is at least one of the temperature and humidity inside or outside the image forming apparatus 1. In this embodiment, the environment sensor 7 includes a temperature sensor as a temperature detection means for detecting at least the temperature inside the image forming apparatus 1, and inputs information (signals) indicating the detection results to the control unit 50.

[0120] 5. Control Procedure 12 is a flow chart showing an outline of the procedure of processing when the intermediate transfer unit 100 in this embodiment is attached to the apparatus main body 2. The processing procedure in this embodiment will be described with reference to FIG.

[0121] When the intermediate transfer unit 100 is attached to the apparatus main body 2 and the power supply of the image forming apparatus 1 is turned ON (S301), the control unit 50 checks (reads) the information on the memory board 4a by the detection circuit 6 at a predetermined timing before the first printing operation (S302). The control unit 50 reads the new / old information in the information acquired from the memory board 4a by the detection circuit 6, and judges whether the belt cleaning device 108 is new or not (S303). If the control unit 50 judges in S303 that the belt cleaning device 108 is new, it next reads the unit configuration information in the information acquired from the memory board 4a by the detection circuit 6, and judges whether the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were shipped as a unit (S304).

[0122] Then, if the control unit 50 determines in S304 that the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were not shipped as a unit, it resets the cleaning counter 71 to the initial value (zero in this embodiment) (S305). On the other hand, if the control unit 50 determines in S304 that the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were shipped as a unit, it resets the cleaning counter 71 and the belt counter 72 to their initial values ​​(zero in this embodiment) (S308).

[0123] The control unit 50 then sets the execution frequency of the supply control based on the count value of the belt counter 72 that was maintained without being reset in S305 or that was reset in S308 (S306). That is, if the count value of the belt counter 72 was maintained without being reset in S305, the control unit 50 does not change the execution frequency of the supply control. On the other hand, if the count value of the belt counter 72 was reset in S308, the control unit 50 changes the execution frequency of the supply control in accordance with the newly updated count value of the belt counter 72.

[0124] Thereafter, the control unit 50 puts the image forming apparatus 1 into a standby state to wait for a job (S307). If the control unit 50 determines in S303 that the belt cleaning device 108 is not new, the process proceeds to S307.

[0125] 6.Effects Thus, in this embodiment, the control unit 50 can control the control unit 50 to execute a supply control for supplying a predetermined toner image transferred from the image carrier 11 to the intermediate transfer body 101 to the contact portion between the cleaning member 181 of the cleaning device 108 and the surface of the intermediate transfer body 101 during non-image formation, and controls the amount of toner supplied to the contact portion by the supply control per predetermined period that correlates with the usage amount of the intermediate transfer body 101 based on the count value by the second counting means (belt counter) 72. In addition, the image forming apparatus 1 may have an environment detection means (environment sensor) 7 that detects the environment, and in this case, the control unit 50 can control the amount of toner supplied to the contact portion by the supply control per predetermined period that correlates with the usage amount of the intermediate transfer body 101 based on the count value by the second counting means 72 and the detection result by the environment detection means 7.

[0126] As described above, according to this embodiment, the apparatus main body 2 can automatically detect whether the belt cleaning device 108 and the belt conveying section 109 (including the intermediate transfer belt 101) have been replaced as a unit. Therefore, when the intermediate transfer belt 101 is replaced, the belt counter 72 can be appropriately reset, and the supply operation can be performed at an appropriate execution frequency according to the amount of use of the intermediate transfer belt 101. Furthermore, according to this embodiment, it is possible to prevent the operator from erroneously resetting the belt counter 72 when only the belt cleaning device 108 is replaced. Therefore, it is possible to prevent the supply operation from being performed unnecessarily frequently. In this way, according to this embodiment, an appropriate amount of supply toner can be supplied to the cleaning section CL according to the amount of use of the intermediate transfer belt 101, and the occurrence of a horizontal stripe-like image defect can be suppressed, and a good image can be formed. Furthermore, according to this embodiment, the supply control is not performed excessively frequently, so that an increase in toner consumption and downtime can be suppressed.

[0127] In this embodiment, the frequency of supply control is set based on the count value of the number of printed sheets by the belt counter 72, but this is not limiting. As long as the index value correlates with the usage amount of the intermediate transfer belt 101, it may be set based on any of predetermined counter information, predetermined conveying distance information, and predetermined period usage information.

[0128] In this embodiment, the amount of toner supplied to the cleaning unit CL is changed by changing the frequency of execution of the supply control, but this is not limiting. The amount of toner supplied to the cleaning unit CL may be changed by changing the size of the supplied toner image in one supply control (the width of the toner band in the transport direction or the width in the direction substantially perpendicular to the transport direction), the concentration of the supplied toner, etc.

[0129] [Example 4] 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 given the same reference numerals as those of embodiment 1, and detailed explanations are omitted.

[0130] 1. Post-rotation toner belt In the case of the intermediate transfer belt 101 having a coating layer for ensuring the releasability of the toner as in this embodiment, the components of the surface layer of the intermediate transfer belt 101 may adhere to the photosensitive drum 11, causing a horizontal stripe-like image defect. That is, after the image formation is completed, the intermediate transfer belt 101 and the photosensitive drum 11 are maintained in contact with each other. At this time, when the intermediate transfer belt 101 is new or in the early stages of use, the components of the surface layer of the intermediate transfer belt 101 may adhere to the photosensitive drum 11, which may hinder the formation of a toner image, causing a horizontal stripe-like image defect. Such horizontal stripe-like image defects due to chemical attack are likely to occur in the black image forming unit S when the intermediate transfer belt 101 is stretched in the above-mentioned monochrome image printing form (FIG. 4(c)) during print standby in order to shorten the time from the start instruction of the monochrome image to the output of the image. In the other image forming units S as well, when the photosensitive drum 11 and the intermediate transfer belt 101 are stopped in contact with each other, the above-mentioned horizontal stripe-like image defect may occur.

[0131] Therefore, a predetermined toner image is interposed between the photosensitive drum 11, which is in contact with the intermediate transfer belt 101 while the image forming apparatus 1 is stopped, and the intermediate transfer belt 101. This makes it possible to suppress adhesion of exuded components to the surface of the photosensitive drum 11, which occurs when the photosensitive drum 11 and the intermediate transfer belt 101 are left in direct contact with each other for a long period of time. For example, before stopping the photosensitive drum 11 and the intermediate transfer belt 101 after the post-rotation process, a band-shaped halftone image or solid image is formed on the photosensitive drum 11, which is in contact with the intermediate transfer belt 101 while the image forming apparatus 1 is stopped. This image is formed along the width direction of the intermediate transfer belt 101 (the direction of the rotation axis of the photosensitive drum 11), for example, in substantially the entire area (substantially the entire area where the photosensitive drum 11 and the intermediate transfer belt 101 are in contact with each other) of the image forming area (area capable of carrying a toner image). Then, the photosensitive drum 11 and the intermediate transfer belt 101 are stopped so that this image is interposed between the photosensitive drum 11 and the intermediate transfer belt 101 at the contact portion between the photosensitive drum 11 and the intermediate transfer belt 101. Here, this image is referred to as a "post-rotation toner band." In this embodiment, a post-rotation toner band (spacer image) is formed between the black photosensitive drum 11 and the intermediate transfer belt 101. Note that this post-rotation toner band may adhere to the surface of either the photosensitive drum 11 or the intermediate transfer belt 101, but is removed by the drum cleaning device 15 and the belt cleaning device 108 in the pre-rotation process when image formation is performed thereafter.

[0132] Fig. 13 is a schematic diagram showing a stop position of the post-rotation toner band on the photosensitive drum 11. As shown in Fig. 13, in order to suppress the occurrence of image defects in the form of horizontal streaks, the operation of the image forming apparatus 1 is stopped so that the post-rotation toner band remains on the photosensitive drum 11 after the end of image formation. Specifically, the primary transfer roller 106 is in contact with the photosensitive drum 11 via the intermediate transfer belt 101, and the post-rotation toner band is disposed on the photosensitive drum 11 between a position facing the primary transfer roller 106 and a position facing the cleaning blade 15a of the drum cleaning device 15.

[0133] However, the phenomenon in which the components of the surface layer of the intermediate transfer belt 101 adhere to the photosensitive drum 11 is likely to occur during a certain period in which the intermediate transfer belt 101 has been used relatively little since its start of use. Therefore, it is preferable to execute the formation of the post-rotation toner band according to the amount of use of the intermediate transfer belt 101 (the count value of the belt counter 72). This makes it possible to suppress the occurrence of the above-mentioned horizontal streak-like image defects while suppressing an increase in toner consumption.

[0134] In this embodiment, whether or not to execute control to form a post-rotation toner band is changed based on the count value of the belt counter 72. That is, in this embodiment, as shown in Table 5, when the count value of the belt counter 72 is less than 50,000 sheets, the post-rotation toner band is formed because there is a possibility that a horizontal streak-like image defect due to the above-mentioned chemical attack will occur. On the other hand, in this embodiment, as shown in Table 5, when the count value of the belt counter 72 is 50,000 sheets or more, the possibility that a horizontal streak-like image defect due to the above-mentioned chemical attack will occur is sufficiently low, so the post-rotation toner band is not formed.

[0135] [Table 5]

[0136] In this manner, in this embodiment, for example, when both the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) are new, control to form the post-rotation toner band is executed. On the other hand, when the belt cleaning device 108 is new and the belt conveying unit 109 is not new, for example, when the amount of usage of the intermediate transfer belt 101 since the beginning of use (when it was new) is greater than a predetermined amount of usage, control to form the post-rotation toner band is not executed. In this manner, the post-rotation toner band can be formed at an appropriate time according to the amount of usage of the intermediate transfer belt 101. This makes it possible to suppress the wasteful formation of the post-rotation toner band and suppress the amount of toner consumption.

[0137] 2. Control Procedure 14 is a flow chart showing an outline of the procedure of processing when the intermediate transfer unit 100 in this embodiment is attached to the apparatus main body 2. The procedure of processing in this embodiment will be described with reference to FIG.

[0138] When the intermediate transfer unit 100 is attached to the apparatus main body 2 and the power supply of the image forming apparatus 1 is turned ON (S401), the control unit 50 checks (reads) the information on the memory board 4a by the detection circuit 6 at a predetermined timing before the first printing operation (S402). The control unit 50 reads the new / old information in the information acquired from the memory board 4a by the detection circuit 6, and judges whether the belt cleaning device 108 is new or not (S403). If the control unit 50 judges in S403 that the belt cleaning device 108 is new, the control unit 50 next reads the unit configuration information in the information acquired from the memory board 4a by the detection circuit 6, and judges whether the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were shipped as a unit (S404).

[0139] Then, if the control unit 50 determines in S404 that the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were not shipped as a unit, it resets the cleaning counter 71 to the initial value (zero in this embodiment) (S405). On the other hand, if the control unit 50 determines in S404 that the belt cleaning device 108 and the belt conveying unit 109 (including the intermediate transfer belt 101) were shipped as a unit, it resets the cleaning counter 71 and the belt counter 72 to their initial values ​​(zero in this embodiment) (S408).

[0140] Then, the control unit 50 sets whether or not to execute control to form the post-rotating toner band based on the count value of the belt counter 72 that was maintained without being reset in S405 or reset in S408 (S406). In other words, if the count value of the belt counter 72 was maintained without being reset in S405, the control unit 50 does not change the setting of whether or not to execute control to form the post-rotating toner band. Also, if the count value of the belt counter 72 was reset in S408, the control unit 50 changes whether or not to execute control to form the post-rotating toner band in accordance with the newly updated count value of the belt counter 72.

[0141] Thereafter, the control unit 50 puts the image forming apparatus 1 into a standby state to wait for a job (S407). If the control unit 50 determines in S403 that the belt cleaning device 108 is not new, the process proceeds to S407.

[0142] 3.Effects Thus, in this embodiment, when stopping the image carrier 11 and intermediate transfer body 101 after image formation, the control unit 50 can control the image carrier 11 and intermediate transfer body 101 to be stopped in a state in which the specified toner image formed on the image carrier is placed between the image carrier 11 and the intermediate transfer body 101 and the intermediate transfer body 101 is abutted against the image carrier 11 via the specified toner image, and performs control to change whether or not the specified toner image is formed based on the count value by the second counting means (belt counter) 72.

[0143] As described above, according to this embodiment, the apparatus main body 2 can automatically detect whether the belt cleaning device 108 and the belt conveying section 109 (including the intermediate transfer belt 101) have been replaced as a unit. Therefore, when the intermediate transfer belt 101 is replaced, the belt counter 72 can be appropriately reset, and control for forming the post-rotation toner band can be executed at an appropriate time according to the usage amount of the intermediate transfer belt 101. Furthermore, according to this embodiment, it is possible to prevent the operator from erroneously resetting the belt counter 72 when only the belt cleaning device 108 is replaced. Therefore, it is possible to prevent the control for forming the post-rotation toner band from being executed in vain. Thus, according to this embodiment, the post-rotation toner band can be formed at an appropriate time according to the usage amount of the intermediate transfer belt 101, and the occurrence of a horizontal stripe-like image defect can be suppressed, and a good image can be formed. Furthermore, according to this embodiment, the post-rotation toner band is not formed at a time when it is less necessary, so that an increase in toner consumption can be suppressed.

[0144] In this embodiment, the presence or absence of the formation of the post-rotation toner band is set based on the count value of the number of printed sheets by the belt counter 72, but this is not limited to this. As long as it is an index value that correlates with the usage amount of the intermediate transfer belt 101, it may be set based on any of predetermined counter information, predetermined conveying distance information, and predetermined period usage information.

[0145] [others] Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above-mentioned embodiments.

[0146] The above-mentioned embodiments can be implemented in any combination of part or all. For example, the control for providing (reporting) information on the usage amount of the intermediate transfer unit in the first embodiment, the initial control in the second embodiment, the supply control in the third embodiment, and the control for forming the post-rotation toner zone in the fourth embodiment may be implemented in whole or in part.

[0147] In the above embodiment, the initial supply control when the belt cleaning device is replaced, and the initial supply control and ATVC control when the intermediate transfer unit is replaced are exemplified as the initial control, but the initial control is not limited to these. The initial control may be any control that is desired to be performed when the belt cleaning device or the intermediate transfer unit is replaced, typically before the first image formation is performed. For example, when the intermediate transfer unit is replaced, the initial control may be a control that measures characteristics such as the surface property and circumference in addition to the electrical resistance value of the intermediate transfer belt.

[0148] In the above embodiment, the memory holder is provided at the leading end of the belt cleaning device when the intermediate transfer unit is attached to the device body, but this is not limited to this. The memory holder may be provided at any position that is detachable from the belt conveying section together with the belt cleaning device.

[0149] The photoconductor is not limited to a drum-shaped member, but may be an endless belt-shaped member. The intermediate transfer body is not limited to an endless belt-shaped member, but may be, for example, a drum-shaped member formed by stretching a sheet over a frame. [Explanation of symbols]

[0150] 1. Image forming device 2. Device body 4 Memory Holder 4a Memory board 5 Connection 5a Contact spring 6 Detection circuit 50 Control section 71 Cleaning counter 72 Belt Counter 73 Intermediate transfer unit counter 100 Intermediate transfer unit 101 Intermediate transfer belt 108 Belt cleaning device

Claims

1. a rotatable image carrier that carries a toner image; an intermediate transfer unit for transferring a toner image formed on the image carrier onto a recording material, the intermediate transfer unit including: an intermediate transfer body capable of circulating and transporting the toner image, which has been primarily transferred from the image carrier, onto the recording material for secondary transfer; and a cleaning device for cleaning the intermediate transfer body; In an image forming apparatus having the intermediate transfer unit is detachable from a main body of the image forming apparatus, and the cleaning device is detachable from the main body of the intermediate transfer unit; the cleaning device is provided with a storage unit that is detachable from the unit body together with the cleaning device; The device body is provided with a control unit capable of reading information from the storage unit, An image forming apparatus characterized in that the control unit is capable of reading from the memory unit first information regarding whether the cleaning device is new or not, and second information regarding whether the intermediate transfer body attached to the intermediate transfer unit is new or not when the intermediate transfer unit equipped with the new cleaning device is attached.

2. a first counting means for counting an index value relating to an amount of use of the cleaning device from when it was new; a second counting means for counting an index value relating to an amount of usage of the intermediate transfer body from when it is new; having 2. The image forming apparatus according to claim 1, wherein the control unit performs control such that, when the intermediate transfer unit is attached to the apparatus main body, (a) if the first information indicates that the cleaning device is new and the second information indicates that the intermediate transfer body attached to the intermediate transfer unit is not new, the control unit resets the counted value by the first counting means to an initial value and does not reset the counted value by the second counting means, and (b) if the first information indicates that the cleaning device is new and the second information indicates that the intermediate transfer body attached to the intermediate transfer unit is new, the control unit resets the counted value by the first counting means to an initial value and also resets the counted value by the second counting means to an initial value.

3. 3. The image forming apparatus according to claim 2, wherein the control unit controls to execute a process for notifying information regarding the usage amount of the intermediate transfer unit based on the count value by the first counting means and the count value by the second counting means.

4. 4. The image forming apparatus according to claim 3, wherein the control unit controls to execute a process for notifying information regarding the usage amount of the intermediate transfer unit based on the larger of the count value of the first counting means and the count value of the second counting means.

5. The image forming apparatus according to claim 1, characterized in that, when the intermediate transfer unit is attached to the device main body, the control unit performs control based on the first information and the second information to execute a predetermined control before forming a first image using the intermediate transfer unit.

6. The image forming apparatus according to claim 5, characterized in that, when the intermediate transfer unit is attached to the apparatus main body and the first information indicates that the cleaning device is new, the control unit performs the specified control such that a specified toner image transferred from the image carrier to the intermediate transfer body is supplied to a contact portion between a cleaning member provided in the cleaning device and the surface of the intermediate transfer body.

7. The image forming apparatus according to claim 1, wherein the control unit, when the intermediate transfer unit is attached to the apparatus main body, (a) if the first information indicates that the cleaning device is new and the second information indicates that the intermediate transfer body attached to the intermediate transfer unit is not new, executes a predetermined first control before forming a first image using the intermediate transfer unit, and (b) if the first information indicates that the cleaning device is new and the second information indicates that the intermediate transfer body attached to the intermediate transfer unit is new, executes a predetermined second control before forming a first image using the intermediate transfer unit.

8. The image forming apparatus according to claim 7, characterized in that the first control is a control for supplying a predetermined toner image transferred from the image carrier to the intermediate transfer body to a contact portion between a cleaning member provided in the cleaning device and the surface of the intermediate transfer body.

9. 8. The image forming apparatus according to claim 7, wherein the second control is a control for applying a voltage to the intermediate transfer body to obtain information regarding an electric resistance of the intermediate transfer body.

10. 8. The image forming apparatus according to claim 7, wherein the control unit performs control so as to also perform the first control when performing the second control.

11. The image forming apparatus according to claim 2, characterized in that the control unit is capable of executing supply control to supply a specified toner image transferred from the image carrier to the intermediate transfer body to a contact portion between a cleaning member provided in the cleaning device and the surface of the intermediate transfer body during non-image formation, and controls to change the amount of toner supplied to the contact portion by the supply control per specified period correlated with the usage amount of the intermediate transfer body based on the counted value by the second counting means.

12. An environment detection means for detecting an environment, The image forming apparatus according to claim 11, characterized in that the control unit performs control so as to change the amount of toner supplied to the contact portion by the supply control per predetermined period correlated with the usage amount of the intermediate transfer body, based on the count value by the second counting means and the detection result by the environment detection means.

13. The image forming apparatus according to claim 2, characterized in that, when stopping the image carrier and the intermediate transfer body after image formation, the control unit is capable of controlling the image carrier and the intermediate transfer body to be stopped in a state in which a predetermined toner image formed on the image carrier is placed between the image carrier and the intermediate transfer body and the intermediate transfer body is abutted against the image carrier via the predetermined toner image, and controls to change whether or not the predetermined toner image is formed based on the count value by the second counting means.

Images