Image forming apparatus and image forming system

Abstract

To provide a new form of an image forming apparatus having a replaceable process cartridge.SOLUTION: An image forming apparatus has: an apparatus main body; a first process cartridge that has a first image carrier and a first developing roller for supplying a first toner to the first image carrier, and is removably attached to the apparatus main body; a toner cartridge that is removably attached to the apparatus main body independently of the first process cartridge, and stores the first toner; and a second process cartridge that has a second image carrier and a second developing roller for supplying a second toner to the second image carrier, is removably attached to the apparatus main body, and does not receive supply of the second toner in a state in which it is attached to the apparatus main body.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus and an image forming system for forming an image on a sheet. [Background technology]

[0002] Image forming devices such as printers, copiers, and multifunction devices use a process cartridge that is detachable from the image forming device body and contains a photosensitive drum and components that act on the photosensitive drum to perform an electrophotographic process. Patent Document 1 describes a process cartridge that integrates a photosensitive drum with a developing unit that includes a developing roller and a developing container. While this system makes it easy to replace the cartridge, it tends to increase running costs because the entire cartridge must be replaced when the toner runs out.

[0003] Meanwhile, Patent Document 2 describes a configuration in which a toner cartridge containing toner (developer) to be replenished to the developing unit is provided detachably to the image forming apparatus main body, separate from a process cartridge equipped with a photosensitive drum and a developing unit. The system using a toner cartridge is superior in terms of running costs when performing mass printing compared to an all-in-one process cartridge, because the toner cartridge can be replaced alone when the toner runs out. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-280242 [Patent Document 2] Japanese Patent Application Publication No. 04-51259 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention is a further development of the technology described in the above document, and has an object to provide a new form of image forming apparatus having a replaceable process cartridge. [Means for solving the problem]

[0006] One aspect of the present disclosure is an image forming apparatus comprising: a process cartridge detachably attached to the device main body, the process cartridge having an apparatus main body, an image carrier, and a developing roller that supplies toner to the image carrier; a toner cartridge detachably attached to the device main body independently of the process cartridge and that contains toner to be replenished to the process cartridge; a movable endless belt whose outer surface contacts the image carrier and onto which a toner image is transferred from the image carrier; a transfer member that contacts the outer surface of the belt to form a transfer section and that transfers the toner image transferred to the belt to a recording material at the transfer section; and a tension roller that contacts the inner surface of the belt downstream of the transfer section and upstream of the image carrier in the rotation direction of the belt and tensions the belt, wherein the toner cartridge is located in a position that overlaps the process cartridge when viewed in the direction of movement of the belt between the tension roller and the image carrier.

[0007] Another aspect of the present disclosure includes a first process cartridge detachably attached to the device main body, the first process cartridge having a first image carrier, a first developing roller that supplies a first toner to the first image carrier, the first process cartridge being detachable from the device main body, a second process cartridge detachably attached to the device main body independently of the first process cartridge, the first toner cartridge containing the first toner, a second image carrier, and a second developing roller that supplies a second toner to the second image carrier, the second toner cartridge detachably attached to the device main body independently of the second process cartridge, the second toner cartridge containing the second toner, the second toner cartridge having an outer surface in contact with the first image carrier and the second image carrier, and a developing roller that is detachable from the first image carrier and the first toner cartridge, the developing roller being detachable from the first image carrier and the first toner cartridge, and the developing roller being ... and the developing roller being detachable from the first image carrier and the first toner cartridge, and the developing roller being detachable from the second image carrier. The image forming device comprises a movable endless belt onto which a toner image is transferred from the second image carrier; a transfer member that contacts the outer surface of the belt to form a transfer section and transfers the toner image transferred to the belt to a recording material at the transfer section; and a tension roller that contacts the inner surface of the belt downstream of the transfer section and upstream of the first image carrier and the second image carrier in the rotation direction of the belt and stretches the belt, wherein each of the first toner cartridge and the second toner cartridge is mounted in a position that overlaps with the first process cartridge and the second process cartridge when viewed in the direction of movement of the belt between the tension roller and the first image carrier. [Effects of the Invention]

[0008] According to the present invention, a new form of image forming apparatus having a replaceable process cartridge can be provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of an image forming system according to a first embodiment. [Figure 2] FIG. 3 is a diagram showing a toner layer transferred onto a sheet in the first embodiment. [Figure 3] FIG. 2 is a rear perspective view of the refill type process cartridge according to the first embodiment. [Figure 4]FIG. 2 is a diagram for explaining a toner supply path according to the first embodiment. [Figure 5] 10A and 10B are diagrams illustrating a modified example of the toner cartridge according to the first embodiment. [Figure 6] 1 is a schematic view of a binding processing device according to a first embodiment. [Figure 7] FIG. 3 is a diagram showing the transfer position of the powder adhesive on the sheet according to the first embodiment. [Figure 8] 5A to 5D are diagrams for explaining the operation of the binding processing device according to the first embodiment. [Figure 9] FIG. 4 is a schematic diagram showing a modified example of the configuration of the device main body according to the first embodiment. [Figure 10] 1A is a schematic diagram of an image forming apparatus according to Example 2, and FIG. 1B is a schematic diagram of an image forming apparatus according to a comparative example. [Figure 11] 10A and 10B are schematic diagrams showing modified cartridge arrangements according to the second embodiment. [Figure 12] FIG. 10 is a schematic diagram of an image forming apparatus according to a third embodiment. [Figure 13] 10A and 10B are schematic diagrams of an image forming apparatus according to a fourth embodiment. [Figure 14] FIG. 10 is a diagram for explaining a toner supply path according to a fourth embodiment. [Figure 15] FIG. 10 is a diagram illustrating a modified example of the toner cartridge according to the fourth embodiment. [Figure 16] FIG. 10 is a schematic diagram of an image forming apparatus according to a modified example of the fourth embodiment. [Figure 17] 13A and 13B are diagrams for explaining a toner supply path according to a modified example of the fourth embodiment. [Figure 18] FIG. 10 is a schematic diagram of an image forming apparatus according to a fifth embodiment. [Figure 19] FIG. 10 is a diagram illustrating a toner supply path according to a fifth embodiment. [Figure 20] 13A and 13B are diagrams illustrating a toner replacement operation and a scanner unit according to a fifth embodiment. [Figure 21] FIG. 10 is a schematic diagram of an image forming apparatus according to a sixth embodiment. [Figure 22] FIG. 13 is a diagram for explaining a toner supply path according to a sixth embodiment. [Figure 23]13A and 13B are diagrams illustrating a toner replacement operation and a scanner unit according to a sixth embodiment. [Figure 24] FIG. 10 is a schematic diagram of an image forming apparatus according to a modified example of the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. [Example]

[0011] FIG. 1 is a schematic diagram of an image forming system 1S according to a first embodiment. The image forming system 1S is composed of an image forming apparatus 1 and a post-processing apparatus 6. In the image forming system 1S, an image is formed on a sheet, which is a recording material, by the image forming apparatus 1, and the image is processed by the post-processing apparatus as necessary and output as a finished product. Note that the sheet S can be a variety of sheet materials of different sizes and materials, such as paper such as plain paper and cardboard, sheet materials with surface treatments such as plastic film, cloth, and coated paper, and sheet materials with special shapes such as envelopes and index paper.

[0012] (Outline of image forming device) The image forming apparatus 1 is an electrophotographic apparatus equipped with an electrophotographic image forming unit 1B inside the apparatus main body 1A. The image forming unit 1B includes an intermediate transfer belt 8 as an intermediate transfer member and process cartridges 30s, 30k arranged along the intermediate transfer belt 8. Each process cartridge 30s, 30k includes a photosensitive drum 2s, 2k as an image carrier (electrophotographic photosensitive member), a charging device 3s, 3k, and a developing unit 5s, 5k, and is detachably attached to the apparatus main body 1A. The developing unit 5s, 5k includes a container 5s2, 5k2 that contains toner as a developer, and a developing roller 5s1, 5k1 as a developer carrier that is rotatably held in the container and rotates while carrying the toner.

[0013] The process cartridge 30k is a first process cartridge (first cartridge) that forms an image using a first toner. The photosensitive drum 2k is a first image carrier in this embodiment, and the developing roller 5k1 is a first developing roller in this embodiment. The process cartridge 30s is a second process cartridge (second cartridge) that forms an image using a second toner. The photosensitive drum 2s is a second image carrier in this embodiment, and the developing roller 5s1 is a second developing roller in this embodiment. Note that the "device main body 1A" of the image forming apparatus 1 refers to the portion of the image forming apparatus 1 excluding the process cartridges 30s, 30k and the toner cartridge 31. The device main body 1A includes frame members such as a metal frame that form the frame of the image forming apparatus 1 and members fixed to the frame, and forms an installation space into which the process cartridges 30s, 30k and the toner cartridge 31 are installed.

[0014] The process cartridge 30k uses black toner to create a toner image (hereinafter referred to as a toner image) for recording an image on the sheet S. The process cartridge 30s applies a transparent toner (hereinafter referred to as adhesive toner) that is a powder adhesive to the sheet S to create an adhesive toner image. That is, in this embodiment, black toner is used as the first toner, and adhesive toner is used as the second toner. The adhesive toner can be toner particles that are made of the same ingredients and manufactured using the same method as black toner, except that it does not contain a coloring component. For example, toner with a lower melting point than black toner by increasing the wax content can be preferably used. Note that in this embodiment, a transparent toner is used as the adhesive toner contained in the process cartridge 30s, but a white toner, for example, can also be used as the powder adhesive. Furthermore, because the adhesive toner image is transparent, it differs from a normal toner image for recording an image on the sheet S. However, unless otherwise specified, the term "toner image" in the following description includes an adhesive toner toner image unless otherwise specified.

[0015] A toner cartridge 31 containing black toner to be replenished to the process cartridge 30k is detachably mounted on the apparatus main body 1A and is connected to the process cartridge 30k via a toner transport pipe 33. The toner replenishment path from the toner cartridge 31 to the process cartridge 30k will be described later.

[0016] A scanner unit 4 serving as an exposure means (exposure unit) is disposed below the process cartridges 30s, 30k within the apparatus main body 1A. A cassette 13 (also called a sheet tray or storage) serving as a stacking section on which sheets S to be used for image formation are stacked is inserted into the apparatus main body 1A so as to be removable below the scanner unit 4. Furthermore, an optional sheet feeding device 60 including the cassette 13 can be connected below the apparatus main body 1A.

[0017] The intermediate transfer belt 8 is a movable (rotatable) endless belt stretched around a drive roller 9a, a tension roller 9b, and a tension roller 10, which rotate about parallel axes. The intermediate transfer belt 8 moves (rotates, conveys) counterclockwise in the figure as the drive roller 9 rotates. Primary transfer rollers 7k and 7s, serving as primary transfer members, are disposed on the inner periphery of the intermediate transfer belt 8, facing the photosensitive drums 2k and 2s, respectively, with the intermediate transfer belt 8 interposed therebetween. A secondary transfer roller 11, serving as a transfer member (secondary transfer member), is disposed on the outer periphery of the intermediate transfer belt 8, facing the drive roller 9 with the intermediate transfer belt 8 interposed therebetween. In other words, the tension roller 10 contacts the inner surface of the intermediate transfer belt 8 downstream of the transfer portion and upstream of the image carriers (photosensitive drums 2k and 2s) in the rotation direction of the intermediate transfer belt 8, and stretches the intermediate transfer belt 8. A secondary transfer portion, serving as a transfer portion, is formed as a nip between the intermediate transfer belt 8 and the secondary transfer roller 11. The intermediate transfer belt 8, the primary transfer rollers 7k and 7s, and the secondary transfer roller 11 constitute a transfer unit for transferring toner images formed on the photosensitive drums 2k and 2s, which are image carriers, onto the sheet S.

[0018] A belt cleaner 12 serving as cleaning means for cleaning the intermediate transfer belt 8 is provided at a position facing the tension roller 10 across the intermediate transfer belt 8. The belt cleaner 12 includes a cleaning member 12a such as a blade or brush that is disposed in contact with the intermediate transfer belt 8 and removes deposits such as residual toner from the intermediate transfer belt 8, and a waste toner container 35 that serves as a collection container for collecting the deposits removed by the cleaning member 12a.

[0019] A fixing device 18 serving as fixing means is disposed above the secondary transfer unit within the apparatus main body 1A. The fixing device 18 has a thermal fixing configuration that fixes a toner image by heating, and includes, for example, a fixing roller and a pressure roller that sandwich and transport the sheet S, and a heat source (e.g., a halogen lamp) that heats the toner image on the sheet S via the fixing roller.

[0020] (Image formation operation) When the image forming apparatus 1 performs an image forming operation, a sheet S is fed from a cassette 13 at the bottom of the apparatus main body 1A or from a cassette 13 of the sheet feeding device 60 by a feed roller 14 serving as a feeding means, and is separated and conveyed one by one by a separation roller pair 15. The sheet S is conveyed by a pull-out roller 16 toward a registration roller pair 17, and any skew of the sheet S is corrected when the leading edge of the sheet S hits the nip portion of the registration roller pair 17, which is in a stopped state. The registration roller pair 17 sends the sheet S to a secondary transfer unit at a timing synchronized with the progress of the toner image creation process by the image forming unit 1B.

[0021] Meanwhile, in the image forming unit 1B, the photosensitive drums 2s and 2k rotate, and the charging devices 3s and 3k uniformly charge the surfaces of the photosensitive drums 2s and 2k. The scanner unit 4 writes an electrostatic latent image by irradiating the photosensitive drum 2k with laser light based on image information representing an image to be recorded on the sheet S. The developing unit 5k develops this electrostatic latent image with black toner, making it visible as a black toner image. When the post-processing device 6 performs the binding process described below, the scanner unit 4 writes an electrostatic latent image by irradiating the photosensitive drum 2s with laser light based on information indicating the bonding position of the sheet S. The developing unit 5s develops this electrostatic latent image with adhesive toner, forming a toner image of adhesive toner in the area on the photosensitive drum 2s corresponding to the bonding position on the sheet S.

[0022] The toner images formed on the photosensitive drums 2s and 2k (image carriers) are transferred (primary transfer) onto the intermediate transfer belt 8 by the primary transfer rollers 7s and 7k, and are then transported toward the secondary transfer section by the rotation of the intermediate transfer belt 8. Then, at the secondary transfer section, a voltage is applied to the secondary transfer roller 11, so that the toner image is transferred (secondary transfer) onto the sheet S fed from a pair of registration rollers 17. The sheet S that has passed through the secondary transfer section is sent to the fixing device 18, and the toner image is heated and pressurized as it passes through the nip between the fixing roller and the pressure roller, softening the toner, and then fixing the image to the sheet S.

[0023] After passing through the fixing device 18, the conveying path of the sheet S is switched by a switching unit 19. In the case of single-sided printing, the sheet S is guided to a discharge path 20 by the switching unit 19 and is discharged from the apparatus main body 1A by a pair of discharge rollers 21. In this embodiment, the image forming apparatus 1 is connected to the post-processing device 6 via a relay conveying unit 22, and the sheet S discharged from the pair of discharge rollers 21 is delivered to the post-processing device 6 via pairs of conveying rollers 23 and 24 of the relay conveying unit 22. Furthermore, when the relay conveying unit 22 and the post-processing device 6 are not connected, the pair of discharge rollers 21 discharges the sheet S as a product onto a stacking tray 26 provided on the top of the apparatus main body 1A.

[0024] In the case of double-sided printing, the sheet S with an image formed on its first side is guided to the pair of reversing rollers r1 by the switching unit 19, and after being reverse-conveyed (switchback-conveyed) by the pair of reversing rollers r1, is conveyed via the double-sided conveying path r2 toward the pair of registration rollers 17. Then, after passing through the secondary transfer unit and the fixing device 18, an image is formed on the second side opposite to the first side, and the sheet is discharged from the apparatus main body 1A by the pair of discharge rollers 21.

[0025] (Post-treatment device) The post-processing device 6 has a binding device 25 that binds (adheses) the sheets S, and is a sheet processing device that binds a plurality of sheets S on which images are formed by the image forming device 1 and discharges them as a sheet bundle. The post-processing device 6 can also simply discharge the sheets S on which images are formed by the image forming device 1 without binding them.

[0026] The post-processing device 6 receives the sheets S from the relay conveyance unit 22 via an inlet roller pair 40 and discharges them via a conveyance roller pair 41 to a discharge roller pair 42. When binding is not performed, the sheets S are discharged to an upper discharge tray 43 by the discharge roller pair 42. When binding is performed, the discharge roller pair 42 reverses and conveys the sheets S, and a switching member 44 guides the sheets S to a conveyance path toward the binding device 25. The sheets S are sequentially conveyed via conveyance roller pairs 45, 46, and 47 on the conveyance path, and when a predetermined number of sheets S are stacked in the binding device 25, the binding device 25 performs an operation described below to bind the sheets S. The bound sheet bundle is discharged from the binding device 25 and further discharged to the outside of the post-processing device 6 by a bundle discharge roller pair 48 and stacked on a lower discharge tray 49.

[0027] (Process cartridges and toner cartridges) The following describes the cartridges mounted in the image forming apparatus 1 of this embodiment. As described above, the apparatus main body 1A of the image forming apparatus 1 is detachably mounted with the process cartridge 30k that uses black toner, the process cartridge 30s that uses glue toner, and the toner cartridge 31 that contains replenishment toner.

[0028] When the black toner in the developing unit 5k of the process cartridge 30k becomes low due to repeated image forming operations, toner is replenished from the toner cartridge 31 to the developing unit 5k via a replenishment path described below. To replenish black toner in the image forming apparatus 1, the toner cartridge 31 can be replaced while the process cartridge 30k remains installed. On the other hand, when the adhesive toner in the process cartridge 30s becomes low, the entire process cartridge 30s must be replaced, along with the photosensitive drum 2s and developing unit 5s. When the photosensitive drum 2k of the process cartridge 30k or the like reaches the end of its life, the process cartridge 30k can be replaced.

[0029] Incidentally, adhesive toner is generally used more slowly than black toner. Even when adhesive toner is used, the amount used per image forming operation is often less than that of black toner. This is because binding is not always performed when performing image forming operations, and even when binding is performed, adhesive toner often only needs to be transferred to a limited area. Therefore, for black toner, which is consumed relatively quickly, allowing the process cartridge 30k to receive toner replenishment from the toner cartridge 31 reduces the frequency of replacement of the process cartridge 30k and reduces running costs.

[0030] On the other hand, since glue toner is consumed more slowly than black toner, it is unlikely that the process cartridge 30s will need to be replaced frequently. Therefore, by configuring the process cartridge 30s as an integrated (standalone) type in which the entire cartridge is replaced rather than adopting a toner cartridge system, users can easily perform the replacement work. Also, since one toner cartridge can be omitted compared to when the process cartridge 30s is a toner cartridge system, the toner cartridge 31 can be made larger in capacity. In this way, the configuration of this embodiment can be suitably applied when the rate at which toner is consumed varies greatly depending on the type of toner.

[0031] (Modified Cartridge) In this embodiment, the process cartridge 30s contains adhesive toner, but customized color toner (color toner other than black or transparent toner) such as gold, silver, or clear can also be used depending on the user's usage pattern. In other words, the process cartridge 30s can be suitably used as a custom process cartridge that uses a toner different from the toner mainly used to record an image on a sheet. Also, the process cartridge 30k and the toner cartridge 31 may contain color toner other than black. In other words, the first toner and the second toner can be changed depending on the specific configuration of the image forming apparatus 1.

[0032] Furthermore, in this embodiment, the image forming apparatus 1 is described as having two process cartridges 30s, 30k and one toner cartridge 31, but the number of process cartridges and toner cartridges may be changed. For example, the configuration may include three process cartridges and two toner cartridges. When the number of cartridges is changed, some of the multiple process cartridges are of a replenishment type that receives toner from a toner cartridge, and the remaining process cartridges are of an integrated type (independent type) that does not receive toner from a toner cartridge.

[0033] In this embodiment, the process cartridge 30k, which receives toner replenishment from the toner cartridge 31, and the integrated (independent) process cartridge 30s, which does not receive toner replenishment, are described as having a basically common configuration. However, the integrated (independent) process cartridge 30s may have a different configuration from the process cartridge 30k, which receives toner replenishment. For example, the volume of the developing unit 5s of the process cartridge 30s may be made larger than the volume of the developing unit 5s of the process cartridge 30k to ensure an initial filling amount of glue toner. Furthermore, the process cartridge 30s may have a common configuration with the process cartridge 30k, but with an additional toner container for replenishing the developing unit 5s with glue toner.

[0034] (Cartridge placement) Next, we will explain the arrangement of the process cartridges 30s, 30k and the toner cartridge 31. As shown in Fig. 1, the process cartridges 30s, 30k are arranged along the transport direction of the intermediate transfer belt 8. Specifically, the process cartridges 30s, 30k are lined up in the left-right direction in the figure below the intermediate transfer belt 8 so that the photosensitive drums 2s, 2k abut against the outer surface of the intermediate transfer belt 8, which runs in the left-right direction in the figure between the tension roller 10 and the tension roller 9b.

[0035] The direction in which the intermediate transfer belt 8 moves from the tension roller 10, which serves as the first roller that stretches the intermediate transfer belt 8, to the tension roller 9b, which serves as the second roller, is hereinafter referred to as the conveyance direction D1 of the intermediate transfer belt 8. In this embodiment, the process cartridges 30s, 30k are arranged side by side and substantially parallel to the conveyance direction D1 of the intermediate transfer belt 8. When viewed in the conveyance direction D1 of the intermediate transfer belt 8, the rotation axes of the two photosensitive drums 2s, 2k are in a positional relationship in which they substantially overlap, and the developing units 5s, 5k also overlap each other. In other words, when viewed in the conveyance direction D1 of the intermediate transfer belt 8, the areas occupied by the two process cartridges 30s, 30k at least partially overlap, and preferably substantially coincide.

[0036] Here, the process cartridge 30k that uses black toner is disposed downstream in the transport direction D1 of the intermediate transfer belt 8 relative to the process cartridge 30s that uses glue toner. In other words, the position of the primary transfer unit where the toner image of black toner is transferred from the photosensitive drum 2k to the intermediate transfer belt 8 is closer to the secondary transfer unit than the position of the primary transfer unit where the toner image of glue toner is transferred from the photosensitive drum 2s to the intermediate transfer belt 8. In other words, this embodiment is configured such that the second process cartridge, the first process cartridge, and the transfer unit are lined up in this order in the movement direction of the intermediate transfer belt 8. With this configuration, for an execution instruction (job) of an image forming operation that does not use glue toner, the waiting time (first print-out time) from when the job is input until the image is formed on the first sheet S and it is discharged from the image forming system 1S is shortened.

[0037] The reason why the arrangement of this embodiment shortens FPOT will be specifically explained. When a job that does not use adhesive toner is input, the waiting time from when the scanner unit 4 starts writing an electrostatic latent image on the photosensitive drum 2k in the image forming operation described above until the black toner image reaches the secondary transfer unit is defined as T. The waiting time T includes the time it takes for the photosensitive drum 2k to rotate from the exposure position of the scanner unit 4 to the contact position with the intermediate transfer belt 8 (primary transfer unit) and the time it takes for the intermediate transfer belt 8 to be transported from the contact position with the photosensitive drum 2k to the secondary transfer unit. In contrast, if the arrangement of the process cartridges 30s and 30k were reversed, the position of the photosensitive drum 2k would move upstream in the transport direction D1 of the intermediate transfer belt 8 to the position of the photosensitive drum 2s in FIG. 1. As a result, the distance the toner image travels to the secondary transfer unit by the intermediate transfer belt 8 becomes longer, thereby lengthening the waiting time T. The registration roller pair 17 of the image forming apparatus 1 transports the sheet to the secondary transfer unit in time with the timing at which the toner image reaches the secondary transfer unit, so if the waiting time T is long, the start of transfer of the toner image to the sheet is delayed, and FPOT becomes longer than in this embodiment. In other words, with the arrangement of this embodiment, the black toner image reaches the secondary transfer unit earlier, making it possible to shorten FPOT.

[0038] Furthermore, according to the arrangement of this embodiment, the toner image of black toner is transferred onto the intermediate transfer belt 8 after the toner image of adhesive toner is transferred onto the intermediate transfer belt 8. Therefore, when the image areas of the toner images of black toner and adhesive toner overlap each other, the black toner overlaps the adhesive toner on the intermediate transfer belt 8. Then, when the black toner and adhesive toner are secondarily transferred onto the sheet S at the secondary transfer portion, the adhesive toner Ts overlaps the black toner Tk on the sheet S, as shown in FIG. 2, and the adhesive toner Ts is located in the outermost layer. By exposing the adhesive toner Ts, which bonds the sheets S together, at the outermost layer, adhesiveness is improved compared to when the adhesive toner Ts is covered by layers of other toners.

[0039] The toner cartridge 31 is also arranged alongside the process cartridges 30s and 30k in the transport direction D1 of the intermediate transfer belt 8. In other words, this embodiment has a configuration in which the toner cartridge, second process cartridge, first process cartridge, and transfer unit are arranged in this order in the movement direction of the intermediate transfer belt 8. The toner cartridge 31 is arranged upstream of the process cartridges 30s and 30k in the transport direction D1 of the intermediate transfer belt 8, below the belt cleaner 12. When viewed in the transport direction D1 of the intermediate transfer belt 8, at least a portion of the toner cartridge 31 overlaps with the process cartridges 30s and 30k.

[0040] To shorten the supply path from toner cartridge 31 to process cartridge 30k, it is also possible to position toner cartridge 31 adjacent to process cartridge 30k and move it between process cartridges 30s and 30k. However, in this modification, the primary transfer unit of process cartridge 30s moves upstream in the transport direction D1 and away from the secondary transfer unit compared to this embodiment, which would likely increase the FPOT for jobs using adhesive toner Ts. Furthermore, separating process cartridges 30s and 30k would require a longer circumferential length of intermediate transfer belt 8 compared to this embodiment, which would require a larger scanner unit 4. Positioning process cartridges 30s and 30k adjacent to each other and toner cartridge 31 upstream of them, as in this embodiment, would shorten the FPOT and reduce the device's size. The arrangement of toner cartridge 31 and process cartridges 30s and 30k can be modified as needed, and their order in the transport direction D1 may be reversed, or an arrangement other than one substantially parallel to the transport direction D1 may be adopted.

[0041] (Toner supply path) Next, the toner supply configuration of the process cartridge 30k will be described with reference to Figures 3 and 4. Figure 3 is a perspective view of the process cartridge 30k having a supply port 32 for supplying toner. Figure 4 is a diagram for explaining the toner supply path. Both Figures 3 and 4 show the image forming apparatus 1 as viewed from the rear side (the back side of Figure 1).

[0042] As shown in FIG. 3, a supply port 32 is provided on the rear side of the process cartridge 30k. The supply port 32 is in communication with the space inside the developing unit 5k of the process cartridge 30k. As shown in FIG. 4, the supply port 32 is connected to the discharge port of the toner cartridge 31 via a toner transport pipe 33 provided in the apparatus main body 1A. A screw (not shown) is disposed inside the toner transport pipe 33. When the screw is driven by the drive unit 33D, toner is transported from the toner cartridge 31 to the process cartridge 30k, and the toner is replenished to the process cartridge 30k.

[0043] On the other hand, the process cartridge 30s that uses glue toner does not have a supply port that communicates with the outside, or if it does have a supply port, it is blocked by a cover member, and is configured so that toner is not replenished from the toner cartridge when it is attached to the apparatus main body 1A. Therefore, when the amount of glue toner remaining in the process cartridge 30s becomes low, the entire process cartridge 30s is removed from the apparatus main body 1A and replaced with a process cartridge 30s filled with glue toner.

[0044] In this embodiment, the toner cartridge 31 is attached to and detached from the apparatus main body 1A independently of the belt cleaner 12. However, as a modified example, the toner cartridge 31 and the waste toner container 35 of the belt cleaner 12 may be configured as an integrated unit 34, as shown in FIG. 5. In this case, when the toner level in the toner cartridge 31 becomes low, the toner cartridge 31 and the waste toner container 35 are replaced with new ones by replacing the unit 34. This reduces the number and frequency of replacements compared to replacing the toner cartridge 31 and the waste toner container 35, which are consumables, separately, thereby improving convenience. Regarding the extent to which the toner cartridge 31 is integrated, only the waste toner container 35 may be integrated with the toner cartridge 31, or the entire belt cleaner 12, including the cleaning member 12a, may be integrated with the toner cartridge 31.

[0045] In addition, in this embodiment, the toner cartridge 31 and the process cartridge 30k are described as being connected via the toner transport pipe 33 provided in the apparatus main body 1A. However, the present invention is not limited to this, and the toner cartridge 31 may be configured so that the discharge port of the toner cartridge 31 and the supply port 32 of the process cartridge 30k are directly connected when the toner cartridge 31 is attached to the apparatus main body 1A.

[0046] (Binding processing device) The following describes the detailed configuration of the binding device 25. Fig. 6 is a perspective view of the binding device 25 according to this embodiment. The binding device 25 includes an alignment mechanism 57 and an adhesive mechanism 58.

[0047] The alignment mechanism 57 includes an alignment tray 50, leading edge alignment portions 51f, 51r, side edge reference plates 52L, 52L, an alignment plate 53, and a bundle discharge guide 54. The alignment tray 50 is a stacking portion (sheet support portion) on which a plurality of sheets to be bound (adhesive) are stacked. The sheets conveyed to the binding processing device 25 by the conveying roller pair 47 (FIG. 1) of the post-processing device 6 are sequentially stacked on the alignment tray 50.

[0048] The leading edge alignment portions 51f, 51r are alignment members (alignment references) against which the leading edge of the sheet strikes in the sheet conveying direction by the conveying roller pair 47 to align the sheet position in the first direction X. In this embodiment, the leading edge alignment portions 51f, 51r align the sheets due to the weight of the sheets stacked on the alignment tray 50. For this reason, the alignment tray 50 is arranged at an incline so that the position in the direction of gravity decreases as the sheet approaches the leading edge alignment portions 51f, 51r in the first direction X (see FIG. 1). However, the sheet may also be aligned by moving the sheet in the first direction X using a moving member such as a roller member or knurled belt arranged above the alignment tray 50 and striking the sheet against the leading edge alignment portions 51f, 51r.

[0049] The side edge reference plates 52L, 52R are members (alignment references) that serve as references for the sheet position in a second direction Y perpendicular to the first direction X, and are provided on one side of the alignment tray 50 in the second direction Y. The alignment plate 53 is a member that moves in the second direction Y to align the sheet position in the second direction Y. After sheets are loaded on the alignment tray 50, the alignment plate 53 moves in the second direction Y to approach the side edge reference plates 52L, 52R, causing the side edges of the sheets to abut against the side edge reference plates 52L, 52R, thereby aligning the sheet position in the second direction Y.

[0050] The bundle discharge guide 54 has a claw portion that protrudes upward from the stacking surface of the alignment tray 50, and is a pushing member that moves along the first direction X to push the sheet bundle out of the alignment tray 50. After the sheets stacked on the alignment tray 50 are bound by the adhesive mechanism 58, the bundle discharge guide 54 moves in the discharge direction (here, the direction opposite to the first direction X) while pressing the sheet bundle with the claw portion, thereby pushing out the sheet bundle. The bundle discharge guide 54 moves to a position where it delivers the sheet bundle to the pair of bundle discharge rollers 48 (FIG. 1), and then returns to the position shown in FIG. 6.

[0051] The bonding mechanism 58 includes a heating device 55 with a built-in heater, a motor 59 that raises and lowers the heating device 55 relative to the alignment tray 50, and a pressure spring 56 that urges the heating device 55 toward the alignment tray 50.

[0052] The operation of the binding process will be described with reference to Figures 7 and 8(a-d). Figure 7 is a diagram showing an example of the transfer position of glue toner on a sheet. Figure 8 is a diagram for explaining the binding process operation by the binding device 25. When binding a sheet after image formation for the purpose of creating a booklet or the like, the sheet S on which an image has been formed by the image forming apparatus 1 is handed over to the post-processing device 6 and conveyed to the binding device 25. At this time, as shown in Figure 7, a toner image of black toner created by the process cartridge 30k and a toner image 36 of glue toner created by the process cartridge 30s are formed on the sheet S.

[0053] The binding device 25 of this embodiment has the function of binding sheets S of A4 size or the like along their long edges. That is, the sheets S shown in FIG. 7 are stacked on the alignment tray 50 with the long edge on which the toner image 36 of adhesive toner is formed positioned at the rear side in FIG. 6 . In this embodiment, the heating device 55 is disposed on the rear side of the post-processing device 6 (the rear side in FIG. 1 ) to further improve safety during jam clearance. That is, if a sheet jam occurs in the binding device 25, the user opens a door provided on the front side of the post-processing device 6, accesses the binding device 25 from the front side, and removes the sheet. In this case, the heating device 55 is disposed on the rear side of the post-processing device 6, reducing the possibility of the user coming into contact with the heating device 55. However, depending on the specific configuration of the post-processing device 6, the heating device 55 may be disposed on the front side of the post-processing device 6 or on the lower right side in FIG. 1 . Furthermore, since the position at which the sheet can be adhered is determined by the location of the heating device 55, the number and combination of heating devices 55 may be changed.

[0054] 8(a), when the sheet S is discharged onto the alignment tray 50, the sheet S moves in the first direction X along the inclination of the alignment tray 50 due to its own weight and comes into contact with the leading edge alignment portions 51f, 51r, thereby aligning the sheet position in the first direction X. Subsequently, as shown in FIG. 8(b), the alignment plate 53 is driven by a drive unit (not shown) to move in the second direction Y, whereby the sheet S comes into contact with the side edge reference plates 52L, 52R, thereby aligning the sheet position in the second direction Y.

[0055] When multiple sheets S, including the sheet S to which the adhesive toner has been transferred, are aligned on the alignment tray 50, as shown in FIG. 8(c), the heater of the heating device 55 is heated and the motor 59 lowers the heating device 55. As a result, the heating device 55 is pressed against the sheet stack by the biasing force of the pressure spring 56. At this time, the heating device 55 contacts the sheet stack at a position corresponding to the area of ​​the sheet S to which the adhesive toner has been transferred. The adhesive toner on the sheet S is softened by the heat and pressure applied by the heating device 55, and the sheet S comes into close contact with the opposing sheet S, and then the sheets S are fixed together, thereby adhering the sheets S to each other via the adhesive toner.

[0056] The above operation is repeated until the predetermined number of sheets S specified in the job including the request for binding processing are stacked on the alignment tray 50, thereby forming a sheet bundle in which the predetermined number of sheets S are adhered to each other with adhesive toner. Thereafter, as shown in FIG. 8(d), the bound sheet bundle is conveyed by the bundle discharge guide 54 to the pair of bundle discharge rollers 48 and discharged onto the lower discharge tray 49.

[0057] As described above, in this embodiment, the process cartridge 30k that receives toner replenishment from the toner cartridge 31 and the process cartridge 30s that does not receive toner replenishment are arranged along the intermediate transfer belt 8. This makes it possible to achieve both reduced running costs due to the toner cartridge 31 and the convenience of an integrated process cartridge in a configuration that uses multiple types of toner.

[0058] In this embodiment, the process cartridges 30s, 30k and the toner cartridge 31 are disposed below the intermediate transfer belt 8, but as shown in FIG. 9, these cartridges may also be disposed above the intermediate transfer belt 8. In this case, the process cartridges 30s, 30k are disposed approximately parallel to the transport direction D1 of the intermediate transfer belt 8, which is the opposite direction compared to this embodiment. In addition, it is preferable that the process cartridge 30k be disposed downstream of the process cartridge 30s in the transport direction D1. Furthermore, it is preferable that the toner cartridge 31 be disposed so as to be aligned with the process cartridges 30s, 30k in the transport direction D1, and be disposed downstream of the process cartridges 30s, 30k in the transport direction D1.

[0059] Furthermore, the tension direction of the intermediate transfer belt 8 is not limited to the substantially horizontal direction, but may be a direction obliquely intersecting the horizontal direction or a substantially vertical direction when viewed in the main scanning direction during image formation. Therefore, the transport direction D1 of the intermediate transfer belt 8 is not limited to the direction shown in Figures 1, 8, etc. Furthermore, for example, the process cartridges 30s, 30k may be arranged on one side below or above the intermediate transfer belt 8, and the toner cartridge 31 may be arranged on the other side of the intermediate transfer belt 8. [Example]

[0060] Next, an image forming apparatus according to a second embodiment will be described. The image forming apparatus of this embodiment has a configuration in which the image forming apparatus 1 using four process cartridges is partially modified. Furthermore, the image forming apparatus of this embodiment can be combined with a post-processing device 6 to form an image forming system 1S, just like the image forming apparatus 1 of the first embodiment. Hereinafter, elements with the same reference numerals as those of the first embodiment will be described as having substantially the same configuration and function as those of the first embodiment.

[0061] FIG. 10(a) is a schematic diagram of the image forming apparatus of this embodiment configured as a monochrome image forming apparatus 1M having the function of transferring (applying) adhesive toner to a sheet. Like the image forming apparatus 1 of Embodiment 1, the monochrome image forming apparatus 1M has a process cartridge 30k that receives toner replenishment from a toner cartridge 31 and an integrated (independent) process cartridge 30s that does not receive toner replenishment. The process cartridges 30s and 30k are arranged along the intermediate transfer belt 8, with the toner cartridge 31, process cartridges 30s, and 30k lined up in this order along the conveying direction D1 of the intermediate transfer belt 8. The process cartridge 30k creates a toner image using black toner, and the process cartridge 30s creates a toner image using adhesive toner to be transferred to the adhesive position of the sheet.

[0062] 10(b) is a schematic diagram of a comparative example of a color image forming apparatus 1C that includes an apparatus main body 1A having the same basic configuration as the present embodiment and forms full-color images using four color toners. The color image forming apparatus 1C does not include a toner cartridge 31 or a process cartridge 30s, but includes process cartridges 30y, 30m, and 30c that create toner images using yellow, magenta, and cyan toners. The four process cartridges 30y, 30m, 30c, and 30k are disposed below the intermediate transfer belt 8 and are aligned in this order along the conveyance direction D1 of the intermediate transfer belt 8.

[0063] The monochrome image forming apparatus 1M and the color image forming apparatus 1C basically have the same configuration except for the process cartridges 30s, 30k, 30y, 30m, and 30c and the toner cartridge 31. For example, the monochrome image forming apparatus 1M and the color image forming apparatus 1C can use the same intermediate transfer belt 8 and scanner unit 4.

[0064] However, among the elements constituting the color image forming apparatus 1C, there is no need to provide in the monochrome image forming apparatus 1M those for the process cartridges 30y, 30m that do not exist in the monochrome image forming apparatus 1M. For example, the primary transfer rollers 7y, 7m (FIG. 10(b)) corresponding to the process cartridges 30y, 30m and the polygon motor in the scanner unit 4 can be omitted. Also, the drive motors that drive the photosensitive drums 2y, 2m of the process cartridges 30y, 30m and the high-voltage boards that apply voltage to the charging devices 3y, 3m and developing units 5y, 5m of the process cartridges 30y, 30m can be omitted.

[0065] 10(a) and 10(b), at least a part of the space in which process cartridges 30y, 30m, and 30c are installed in color image forming apparatus 1C is utilized to install toner cartridge 31 in monochrome image forming apparatus 1M. Therefore, when viewed in the direction of gravity (vertical direction), toner cartridge 31 at least partially overlaps intermediate transfer belt 8 and scanner unit 4. Furthermore, at least a part of the space in which process cartridges 30y, 30m, and 30c for creating color images are installed in color image forming apparatus 1C is utilized to install process cartridge 30s that uses glue toner in monochrome image forming apparatus 1M.

[0066] To mount the toner cartridge 31 in the mounting space, in this embodiment, the toner cartridge 31 and the process cartridges 30s and 30k are arranged side by side along the intermediate transfer belt 8. That is, as shown in FIG. 10(a), the toner cartridge 31 is mounted at a position overlapping the process cartridges 30s and 30k when viewed in the transport direction D1 of the intermediate transfer belt 8 between the tension roller 10 and the photosensitive drum 2s. Note that the transport direction D1 is substantially the same as the transport direction D1 of the intermediate transfer belt 8 between the tension roller 10 and the stretching roller 9b. In other words, the toner cartridge in this embodiment is mounted at a position overlapping the first process cartridge and the second process cartridge when viewed in the belt movement direction (D1) between the tension roller and the first image carrier.

[0067] In terms of its position relative to the scanner unit 4, the toner cartridge 31 is mounted between the scanner unit 4 and the intermediate transfer belt 8 in the orthogonal direction Dv of the intermediate transfer belt 8. When viewed in the orthogonal direction Dv, the toner cartridge 31 at least partially overlaps the intermediate transfer belt 8 and the scanner unit 4. The orthogonal direction Dv is a direction orthogonal to the conveying direction D1 of the intermediate transfer belt 8 (particularly, a direction orthogonal to the conveying direction D1 at the contact position with the photosensitive drum 2k) when viewed in the main scanning direction (the direction of the rotation axis of the photosensitive drum 2k) during image formation. In the drawing, the intermediate transfer belt 8 is stretched approximately horizontally, and the orthogonal direction Dv is substantially parallel to the vertical direction, but the orthogonal direction Dv may be inclined with respect to the vertical direction depending on the stretching direction of the intermediate transfer belt 8.

[0068] That is, when viewed in the direction of the rotation axis of the first image carrier (photosensitive drum 2k), the exposure unit of this embodiment is disposed at a position where the first process cartridge and the second process cartridge are sandwiched between the exposure unit and the belt in the orthogonal direction (Dv) perpendicular to the belt movement direction (D1) at the contact portion with the first image carrier. Furthermore, when viewed in the direction of the rotation axis of the first image carrier, the toner cartridge of this embodiment is disposed on the same side of the belt as the first process cartridge and the second process cartridge in the orthogonal direction (Dv), and on the same side of the exposure unit as the first process cartridge and the second process cartridge in the orthogonal direction (Dv). This configuration makes it possible to realize the configuration of a monochrome image forming apparatus 1M that utilizes a device main body common to the color image forming apparatus 1C.

[0069] 10(a) in the conveying direction D1. Also, when an LED exposure unit is used as the exposure unit, for example, the toner cartridge 31 does not need to be disposed between the exposure unit and the intermediate transfer belt 8 in the orthogonal direction Dv. Even in this case, the same advantages as those of this embodiment can be obtained by disposing the toner cartridge 31 along the intermediate transfer belt 8 so that it overlaps with the process cartridges 30s and 30k when viewed in the conveying direction D1.

[0070] In this way, the monochrome image forming apparatus 1M can be provided according to the user's purpose, and the space previously occupied by the process cartridges 30y, 30m, and 30c in the color image forming apparatus 1C can be effectively utilized to accommodate the large-capacity toner cartridge 31. This reduces the running costs of the image forming apparatus. Furthermore, by combining the monochrome image forming apparatus 1M with an all-in-one process cartridge 30s that uses special toner such as glue toner, the monochrome image forming apparatus can be endowed with a variety of functions. In particular, by using glue toner in the all-in-one process cartridge 30s, sheets can be bound using the same binding device 25 as in the first embodiment.

[0071] (Variation) In this embodiment, the arrangement of cartridges in the monochrome image forming apparatus 1M can be modified as needed. For example, as shown in FIG. 11(a), the toner cartridge 31 may be installed between the process cartridges 30s and 30k in the transport direction D1 of the intermediate transfer belt 8. This modification is an example of a configuration in which the second process cartridge, the toner cartridge, the first process cartridge, and the transfer unit are arranged in this order in the movement direction of the intermediate transfer belt 8. Also, as shown in FIG. 11(b), the toner cartridge 31 may be installed downstream of the process cartridges 30s and 30k in the transport direction D1 of the intermediate transfer belt 8. This modification is an example of a configuration in which the second process cartridge, the first process cartridge, the toner cartridge, and the transfer unit are arranged in this order in the movement direction of the intermediate transfer belt 8. Furthermore, a configuration in which the first process cartridge, the second process cartridge, and the transfer unit are arranged in this order in the movement direction of the intermediate transfer belt 8 (including a configuration in which the toner cartridge, the first process cartridge, the second process cartridge, and the transfer unit are arranged in this order) may be used.

[0072] Furthermore, in the monochrome image forming apparatus 1M according to this embodiment, the three process cartridges 30y, 30m, and 30c in the color image forming apparatus 1C are replaced with one process cartridge 30s and one toner cartridge 31. However, for example, one of the process cartridges in the color image forming apparatus 1C may be replaced with a toner cartridge 31, and toner may be replenished from the toner cartridge 31 to any one of the process cartridges. For example, the monochrome image forming apparatus 1M may be configured to have a process cartridge 30k that uses black toner, two process cartridges that use the other two color toners or clear toner, and a toner cartridge 31 that replenishes black toner to the process cartridge 30k. [Example]

[0073] Next, an image forming apparatus 100 according to a third embodiment will be described. Fig. 12 is a schematic diagram of the image forming apparatus 100 according to this embodiment. This embodiment employs a direct transfer method in which a toner image is transferred from an image carrier (electrophotographic photosensitive member) to a recording material without passing through an intermediate transfer member.

[0074] 12, the image forming apparatus 100 has an image forming unit 100B including process cartridges 130k and 130s arranged along an electrostatic attraction belt 108, and a toner cartridge 131. The process cartridge 130k as a first process cartridge, the process cartridge 130s as a second process cartridge, and the toner cartridge 131 are each independently detachable from the apparatus main body 100A of the image forming apparatus 100.

[0075] The process cartridges 130k and 130s each include a photosensitive drum 102 or 102s serving as an image carrier, a charging device 103k or 103s, and a developing unit 105k or 105s having a developing roller and a toner container. The developing unit 105k of the process cartridge 130k contains black toner, and the developing unit 105s of the process cartridge 130s contains glue toner. The toner cartridge 131 contains black toner to be replenished to the process cartridge 130k, and the discharge port of the toner cartridge 131 is connected to the replenishment port of the process cartridge 130k via a toner transport pipe 133. A scanner unit 104 is disposed above the process cartridges 130k and 130s.

[0076] The process cartridge 130k is the first process cartridge (first cartridge) in this embodiment, the photosensitive drum 102k is the first image carrier in this embodiment, and the developing roller of the developing unit 105k is the first developing roller in this embodiment. The process cartridge 130s is the second process cartridge (second cartridge) in this embodiment, the photosensitive drum 102s is the second image carrier in this embodiment, and the developing roller of the developing unit 105s is the second developing roller in this embodiment.

[0077] The electrostatic attraction belt 108 is an endless conveyor belt that conveys the sheet S through a transfer unit where a toner image is transferred. The electrostatic attraction belt 108 is stretched between a drive roller 109 and a tension roller 110, and is driven in a clockwise direction in the figure by the rotation of the drive roller 109. Hereinafter, the direction in which the electrostatic attraction belt 108 is conveyed from the tension roller 110, which serves as a first roller, to the drive roller 109, which serves as a second roller (the direction in which the surface of the electrostatic attraction belt 108 that contacts the sheet S moves) is referred to as a conveyance direction D2 of the electrostatic attraction belt 108. A thermal fixing type fixing device 118 is disposed downstream of the electrostatic attraction belt 108 in the conveyance direction D2.

[0078] The photosensitive drums 102k, 102s of the process cartridges 130k, 130s are in contact with the upper surface of the electrostatic attraction belt 108. Transfer rollers 107k, 107s as transfer members are arranged inside the electrostatic attraction belt 108 at positions facing the photosensitive drums 102, 102s. A transfer unit where a toner image is transferred is formed as a nip between the transfer rollers 107k, 107s and the photosensitive drums 102k, 102s. A sheet feeding unit including a cassette 113 as a stacking unit and a feeding roller 114 as a feeding means is provided below the electrostatic attraction belt 108.

[0079] (Cartridge placement) Here, the arrangement of the process cartridges 130k, 130s and the toner cartridge 131 will be described. In this embodiment, the toner cartridge 131, process cartridge 130k, and process cartridge 130s are arranged in this order from upstream to downstream in the transport direction D2, substantially parallel to the transport direction D2 of the electrostatic attraction belt 108. When viewed in the transport direction D1 of the intermediate transfer belt 8, the areas occupied by the two process cartridges 130s, 130k at least partially overlap, and preferably substantially coincide. Furthermore, when viewed in the transport direction D1 of the intermediate transfer belt 8, at least a portion of the toner cartridge 131 overlaps with the process cartridges 130s, 130k.

[0080] Unlike in the first embodiment, the process cartridge 130k using black toner is disposed upstream in the transport direction D2 relative to the process cartridge 130s using glue toner. This is because, in a direct transfer type configuration, the toner image transferred further downstream in the transport direction D2 is positioned closer to the front side of the sheet S, and therefore, disposing the process cartridge 130s using glue toner downstream is advantageous in terms of adhesion during binding. Also, because the process cartridge 130k using black toner is adjacent to the toner cartridge 131, the length of the toner transport pipe 133 can be shortened.

[0081] (Image formation operation) When the image forming apparatus 1 performs an image forming operation, a sheet S is fed from a cassette 113 by a feeding roller 114, and is separated and conveyed one by one by a separation roller pair 115. The sheet S is subjected to skew correction and timing adjustment by a registration roller pair 117, and then delivered to the electrostatic adsorption belt 108.

[0082] Meanwhile, in the image forming unit 100B, the photosensitive drums 102k and 102s rotate, and the charging devices 103 and 103s uniformly charge the surfaces of the photosensitive drums 102k and 102s. The scanner unit 104 irradiates the photosensitive drums 102k and 102s with laser light to write an electrostatic latent image. This electrostatic latent image is developed with black toner or glue toner supplied from the developing units 105k and 105s, forming a toner image on the photosensitive drums 102k and 102s.

[0083] The toner images formed on the photosensitive drums 102k, 102s are transferred by transfer rollers 107k, 107s onto a sheet S being transported by an electrostatic adsorption belt 108. After passing through the transfer section, the sheet S is sent to a fixing device 118, where the toner on the sheet S is heated and pressurized, thereby fixing the image to the sheet S. After passing through the fixing device 118, the sheet S is discharged from the apparatus main body 1A by a pair of discharge rollers 121. In the case of double-sided printing, the sheet S is sent to a double-sided transport path r2 by reversal transport by a pair of reversing rollers r1, and after an image is formed on the second side, it is discharged from the apparatus main body 1A by the pair of discharge rollers 121.

[0084] As in the first embodiment, the image forming apparatus 100 of this embodiment can also be used in combination with a post-processing device 6 (FIG. 1) that performs binding processing on sheets S. In this case, the sheets S discharged from the pair of discharge rollers 121 are delivered to the post-processing device 6, temporarily stacked in the binding device 25 in the post-processing device 6, subjected to binding processing, and then discharged as a sheet bundle to the discharge tray of the post-processing device 6.

[0085] As described above, in this embodiment, a configuration has been described in which the process cartridge 130k, which receives toner replenishment from the toner cartridge 131, and the process cartridge 130s, which does not receive toner replenishment, are arranged along the electrostatic adsorption belt 108. This makes it possible to achieve both reduced running costs due to the toner cartridge 131 and the convenience of the integrated process cartridge 130s in a configuration using multiple types of toner. Furthermore, by using glue toner in the integrated process cartridge 130s, it is possible to perform binding processing on sheets using the binding device 25 similar to that of the first embodiment. [Example]

[0086] Next, an image forming apparatus according to Example 4 will be described. In the following, elements with the same reference numerals as those in Example 1 will be described as having substantially the same configurations and functions as those in Example 1.

[0087] FIG. 13(a) is a schematic diagram of the image forming apparatus of this embodiment configured as a monochrome image forming apparatus 200. The monochrome image forming apparatus 200 has a process cartridge 30k that receives toner replenishment from a toner cartridge 31. The process cartridge 30k is arranged along the intermediate transfer belt 8, with the toner cartridge 31 and the process cartridge 30k lined up in this order along the conveying direction D1 of the intermediate transfer belt 8. The process cartridge 30k creates a toner image using black toner. In other words, the monochrome image forming apparatus 200 forms a black monochrome image on a sheet S using an image forming unit including the process cartridge 30k.

[0088] As with the second embodiment, the image forming apparatus of this embodiment can also be configured as a color image forming apparatus by replacing the process cartridge. That is, the configuration of the monochrome image forming apparatus 200 according to this embodiment and the color image forming apparatus 1C (FIG. 10(b)) can be basically the same, except for the process cartridges 30k, 30y, 30m, and 30c and the toner cartridge 31. Furthermore, among the components constituting the color image forming apparatus 1C (FIG. 10(b)), there is no need to provide components for the process cartridges 30c, 30y, and 30m that do not exist in the monochrome image forming apparatus 200 in the monochrome image forming apparatus 200. For example, the primary transfer rollers 7c, 7y, and 7m (FIG. 10(b)) corresponding to the process cartridges 30c, 30y, and 30m and the polygon motor in the scanner unit 4 can be omitted. In addition, it is possible to omit the drive motors that drive the photosensitive drums 2c, 2y, 2m of the process cartridges 30c, 30y, 30m, and the high-voltage boards that apply voltage to the charging devices 3c, 3y, 3m and developing units 5c, 5y, 5m of the process cartridges 30c, 30y, 30m.

[0089] As in the second embodiment, in this embodiment, the toner cartridge 31 and the process cartridge 30k are arranged side by side along the intermediate transfer belt 8. That is, as shown in Fig. 13(a), the toner cartridge 31 is mounted at a position overlapping the process cartridge 30k when viewed in the conveying direction D1 of the intermediate transfer belt 8 between the tension roller 10 and the photosensitive drum 2k. In other words, the toner cartridge in this embodiment is mounted at a position overlapping the process cartridge when viewed in the moving direction (D1) of the belt between the tension roller that stretches the belt and the image carrier.

[0090] In terms of its positional relationship with the scanner unit 4, the toner cartridge 31 is mounted between the scanner unit 4 and the intermediate transfer belt 8 in the orthogonal direction Dv of the intermediate transfer belt 8. The orthogonal direction Dv is a direction orthogonal to the conveying direction D1 of the intermediate transfer belt 8 when viewed in the main scanning direction (the direction of the rotation axis of the photosensitive drum 2k) during image formation (particularly, a direction orthogonal to the conveying direction D1 at the contact position with the photosensitive drum 2k).

[0091] That is, when viewed in the direction of the rotation axis of the image carrier (photosensitive drum 2k), the exposure unit of this embodiment is disposed at a position where the process cartridge is sandwiched between the exposure unit and the belt in the orthogonal direction (Dv) perpendicular to the belt movement direction (D1) at the contact portion with the image carrier. Furthermore, when viewed in the direction of the rotation axis of the image carrier, the toner cartridge of this embodiment is disposed on the same side of the belt as the process cartridge in the orthogonal direction (Dv), and on the same side of the exposure unit as the process cartridge in the orthogonal direction (Dv). This configuration makes it possible to realize a monochrome image forming apparatus that utilizes a device main body common to a color image forming apparatus.

[0092] Note that, for example, when an LED exposure unit is used as the exposure unit, the toner cartridge 31 does not have to be disposed between the exposure unit and the intermediate transfer belt 8 in the orthogonal direction Dv. Even in this case, the same advantages as those of this embodiment can be obtained by disposing the toner cartridge 31 along the intermediate transfer belt 8 so that it overlaps with the process cartridge 30k when viewed in the transport direction D1.

[0093] Next, the toner supply configuration of the process cartridge 30k will be described with reference to Figures 3 and 14. Figure 14 is a diagram for explaining the toner supply path. Figures 3 and 14 both show the image forming apparatus as viewed from the rear side (the back side of Figure 1).

[0094] As shown in FIG. 3, similar to the first embodiment, a supply port 32 is provided on the rear side of the process cartridge 30k. The supply port 32 is in communication with the space inside the developing unit 5k of the process cartridge 30k. As shown in FIG. 14, the supply port 32 is connected to the discharge port of the toner cartridge 31 via a toner transport pipe 33 provided in the main body of the apparatus. A screw (not shown) is disposed inside the toner transport pipe 33. The screw is driven by a drive unit 33D to transport toner from the toner cartridge 31 to the process cartridge 30k, and the toner is replenished to the process cartridge 30k in a similar configuration to the first embodiment.

[0095] As shown in FIG. 13(a), the toner cartridge 31 is installed by effectively utilizing part of the space where the process cartridges 30y, 30m, and 30c were installed in the color image forming apparatus 1C (FIG. 10(b)). Therefore, when viewed in the direction of gravity (vertical direction), the toner cartridge 31 at least partially overlaps the intermediate transfer belt 8. Furthermore, when viewed in the direction Dv perpendicular to the intermediate transfer belt 8, the toner cartridge 31 at least partially overlaps the intermediate transfer belt 8 and the scanner unit 4.

[0096] Furthermore, as shown in FIG. 13(b), the space previously occupied by process cartridges 30y, 30m, and 30c in color image forming apparatus 1C can be utilized to increase the toner cartridge capacity. For example, if the width of the process cartridge in the transport direction D1 of intermediate transfer belt 8 is L1, the width of the toner cartridge in the D1 direction can be increased to the width of the installation space in which process cartridges 30y, 30m, and 30c are installed (three times L1). In other words, in this embodiment, when viewed in the direction of the rotation axis of the image carrier, the width of the toner cartridge in the belt movement direction is greater than the width of the process cartridge in the belt movement direction, but is no more than three times the width of the process cartridge. In this way, the image forming apparatus according to this embodiment can also be configured as a monochrome image forming apparatus 200L equipped with a toner cartridge with a larger capacity than the configuration example shown in FIG. 13(a). This significantly reduces running costs.

[0097] Furthermore, multiple types of toner cartridges with different toner capacities can be prepared as long as they can be installed in the space in the color image forming apparatus 1C where the process cartridges 30y, 30m, and 30c are installed. In this case, the user can select the toner cartridge with the optimal toner capacity depending on the application, improving usability.

[0098] In this embodiment, the arrangement of cartridges in the monochrome image forming apparatus 200 can be changed as needed, and it is also possible to arrange the process cartridges first and then the toner cartridges in the direction of belt movement. As in the first embodiment, the toner cartridge 31L and the waste toner container 35 of the belt cleaner 12 may be configured as an integrated unit 34L as shown in FIG. 15. In this case, the number and frequency of replacements can be reduced compared to when the toner cartridge 31 and the waste toner container 35, which are consumables, are replaced separately, improving convenience. Regarding the extent to which the toner cartridge 31 is integrated, only the waste toner container 35 may be integrated with the toner cartridge 31, or the entire belt cleaner 12, including the cleaning member 12a, may be integrated with the toner cartridge 31.

[0099] (Variation 1) The arrangement and configuration of the toner cartridges in the image forming apparatus according to this embodiment can be modified as appropriate. For example, in the color image forming apparatus 1C (FIG. 10(b)), multiple toner cartridges 31 can be installed to utilize the space for installing the process cartridges 30y, 30m, and 30c. FIG. 16 shows an example of the configuration of a monochrome image forming apparatus 200B in which two toner cartridges 31A and 31B are installed within the apparatus main body. The apparatus main body includes a process cartridge 30k and multiple toner cartridges, i.e., toner cartridges 31A and 31B. The process cartridge 30k is arranged along the intermediate transfer belt 8, with the toner cartridge 31A, toner cartridge 31B, and process cartridge 30k lined up in this order along the transport direction D1 of the intermediate transfer belt 8. The process cartridge 30k receives black toner from both toner cartridges 31A and 31B and uses the black toner to create a toner image.

[0100] In other words, toner cartridge 31B is an example of another toner cartridge that contains the same toner as toner cartridge 31A and is detachable from the apparatus main body independently of process cartridge 30k and toner cartridge 31A. Toner cartridge 31B is mounted in a position that overlaps process cartridge 30k and toner cartridge 31A when viewed in the direction of movement (D1) of intermediate transfer belt 8 between tension roller 10 and image carrier (photosensitive drum 2k).

[0101] The toner transport unit in this modified example will be described with reference to Figures 17(a) and (b). As in the first embodiment, a supply port 32 is provided on the rear side of the process cartridge 30k, and the supply port 32 communicates with the space within the developing unit 5k of the process cartridge 30k. The toner cartridges 31A and 31B are driven by drive units 33DA and 33DB, respectively.

[0102] Next, the toner transport configuration from the two toner cartridges 31A and 31B to the process cartridge 30k will be described. The toner cartridges 31A and 31B are each provided with a discharge port. As shown in FIG. 17(a), the device main body is provided with buffer units 222A and 222B, each having a toner receiving port 221A and 221B, which are driven by drive units 33DA and 33DB, respectively. Each buffer unit 222A and 222B is connected to a common toner transport pipe 220.

[0103] 17(b), when the toner cartridges 31A, 31B are installed in the apparatus main body, the discharge ports of the toner cartridges 31A, 31B are connected (communicated) with the receiving ports 221A, 221B. The buffer units 222A, 222B convey the toner received from the toner cartridges 31A, 31B via the receiving ports 221A, 221B to the toner conveying pipe 220 using a screw (not shown). The toner conveyed from the buffer units 222A, 222B joins together inside the toner conveying pipe 220, and the toner is conveyed to the supply port 32 of the process cartridge 30k.

[0104] In this way, the discharge ports of the multiple toner cartridges 31A, 31B are connected to the supply port 32 of the process cartridge 30k via the buffer units 222A, 222B of the apparatus main body and the toner transport pipe 220. This makes it possible to increase the substantial capacity of the toner cartridges by mounting multiple toner cartridges 31A, 31B in the apparatus main body, even if multiple types of toner cartridges with different toner capacities are not prepared.

[0105] (Variation 2) In the fourth embodiment, a configuration example was shown in which the scanner unit 4 and intermediate transfer belt 8 are arranged with the same dimensions as those of the color image forming apparatus 1C (FIG. 10(b)). However, the scanner unit 4 or the intermediate transfer belt 8 may be arranged to be smaller than those of the fourth embodiment. For example, as shown in FIG. 24, the width of the scanner unit 4S in the transport direction D1 of the intermediate transfer belt 8 may be arranged to be shorter than that of the fourth embodiment. This is because the monochrome image forming apparatus of this modified example is required to have a scanner unit 4S capable of exposing one photosensitive drum 2k, and therefore some elements of the scanner unit 4 are unnecessary compared to the color image forming apparatus 1C (FIG. 10(b)). When the dimensions of the scanner unit or intermediate transfer belt are reduced in this way, the toner cartridge 31 may be arranged so as not to overlap with the scanner unit 4 and the intermediate transfer belt 8 when viewed in the orthogonal direction Dv.

[0106] As described above, as the fourth embodiment and its modified examples, configuration examples in which the toner cartridge 31 and the process cartridge 30k are arranged along the intermediate transfer belt 8 have been described. Also, a configuration example in which a large-capacity toner cartridge (FIG. 13(b)) or multiple toner cartridges (FIG. 16) are arranged by utilizing the space in which the process cartridges 30y, 30m, and 30c are installed in the color image forming apparatus 1C (FIG. 10(b)). This makes it possible to further reduce the running costs of the image forming apparatus. [Example]

[0107] An image forming apparatus 300 according to a fifth embodiment will be described. Fig. 18 is a schematic diagram of the image forming apparatus 300 according to this embodiment. Hereinafter, elements with the same reference numerals as those in the first embodiment will be described as having substantially the same configurations and functions as those in the first embodiment.

[0108] Like the image forming apparatus 1 of the first embodiment, the image forming apparatus 300 of this embodiment can also be combined with a post-processing device 6 (FIG. 1) that performs binding processing on sheets S to form an image forming system 1S. In this case, the sheets S discharged from the pair of discharge rollers 21 are delivered to the post-processing device 6, temporarily stacked in a binding device 25 in the post-processing device 6, subjected to binding processing, and then discharged as a sheet bundle to a discharge tray of the post-processing device 6.

[0109] (Outline of image forming device) The image forming apparatus 300 is an electrophotographic apparatus equipped with an electrophotographic image forming unit 1B inside an apparatus main body 300A. The image forming unit 1B includes an intermediate transfer belt 8 as an intermediate transfer member, and process cartridges 30r and 30k arranged along the intermediate transfer belt 8. Each of the process cartridges 30r and 30k is detachably attached to the apparatus main body 300A. The process cartridge 30k has a photosensitive drum 2k as a first image carrier and is a first process cartridge (first cartridge) that forms an image using a first toner. The process cartridge 30r has a photosensitive drum 2r as a second image carrier and is a second process cartridge (second cartridge) that forms an image using a second toner.

[0110] Here, the process cartridge 30k receives toner supply from the toner cartridge 331k, and the process cartridge 30r receives toner supply from the toner cartridge 331r.

[0111] (Cartridge placement) The process cartridges 30r and 30k are arranged along the intermediate transfer belt 8. The toner cartridge 331r, process cartridge 30r, toner cartridge 331k, and process cartridge 30k are lined up in this order along the transport direction D1 of the intermediate transfer belt 8. In other words, this embodiment has a configuration in which the second toner cartridge, second process cartridge, first toner cartridge, first process cartridge, and transfer unit are lined up in this order in the movement direction of the intermediate transfer belt 8.

[0112] The process cartridge 30k creates a toner image using black toner, while the process cartridge 30r creates a toner image using customized toner. The customized toner is a toner of a customized color such as red, blue, or clear (a colored toner other than black or a transparent toner), and is changed as appropriate depending on the user's usage pattern. Furthermore, by using adhesive toner, the process cartridge 30r and the toner cartridge 331r can bind sheets using the same binding device 25 as in the first embodiment. In other words, the process cartridge 30r can also be suitably used as a custom process cartridge that uses a toner different from the toner mainly used to record images on sheets.

[0113] Here, the "device main body 300A" of the image forming device 300 refers to the portion of the image forming device 300 excluding the process cartridges 30r, 30k and the toner cartridges 331k, 331r. The device main body 300A includes frame members such as a metal frame that constitute the frame of the image forming device 300 and members fixed to the frame, and forms an installation space into which the process cartridges 30r, 30k and the toner cartridges 331r, 331k are installed.

[0114] As described above, in this embodiment, the toner cartridges 331r, 331k and the process cartridges 30r, 30k are arranged side by side along the intermediate transfer belt 8. That is, as shown in Fig. 18, each of the toner cartridges 331r, 331k is mounted at a position where it overlaps with the process cartridges 30r, 30k when viewed in the transport direction D1 of the intermediate transfer belt 8 between the tension roller 10 and the photosensitive drum 2k. In other words, each of the first toner cartridge and the second toner cartridge in this embodiment is mounted at a position where it overlaps with the first process cartridge and the second process cartridge when viewed in the belt movement direction (D1) between the tension roller and the first image carrier.

[0115] In terms of their positional relationship with the scanner unit 4, the toner cartridges 331r and 331k are mounted between the scanner unit 4 and the intermediate transfer belt 8 in the orthogonal direction Dv of the intermediate transfer belt 8. When viewed in the orthogonal direction Dv, the toner cartridges 331r and 331k at least partially overlap the intermediate transfer belt 8 and the scanner unit 4. The orthogonal direction Dv is a direction orthogonal to the transport direction D1 of the intermediate transfer belt 8 when viewed in the main scanning direction (the direction of the rotation axis of the photosensitive drum 2k) during image formation (particularly, a direction orthogonal to the transport direction D1 at the contact position with the photosensitive drum 2k).

[0116] That is, when viewed in the direction of the rotation axis of the first image carrier (photosensitive drum 2k), the exposure unit of this embodiment is disposed at a position where the first process cartridge and the second process cartridge are sandwiched between the exposure unit and the belt in the orthogonal direction (Dv) perpendicular to the belt movement direction (D1) at the contact portion with the first image carrier. Furthermore, when viewed in the direction of the rotation axis of the first image carrier, the first toner cartridge and the second toner cartridge of this embodiment are disposed on the same side of the belt as the first process cartridge and the second process cartridge in the orthogonal direction (Dv), and on the same side of the exposure unit as the first process cartridge and the second process cartridge in the orthogonal direction (Dv). This configuration makes it possible to realize the configuration of an image forming apparatus 300 that utilizes a device main body common to the color image forming apparatus 1C.

[0117] 18 in relation to the conveying direction D1. In other words, the toner cartridges 331r and 331k may be arranged so as not to overlap the scanner unit 4 and the intermediate transfer belt 8 when viewed in the orthogonal direction Dv. Furthermore, when an LED exposure unit is used as the exposure unit, for example, the toner cartridge 31 does not have to be arranged between the exposure unit and the intermediate transfer belt 8 in relation to the orthogonal direction Dv.

[0118] (Toner supply path) Next, the toner supply configuration of the process cartridges 30r and 30k will be described with reference to Figure 19. Figure 19 is a perspective view for explaining the toner supply path, showing the state as seen from the rear side of the image forming apparatus 300 (the far side in Figure 18).

[0119] The supply port 32k of the process cartridge 30k is connected to the discharge port of the toner cartridge 331k via a toner transport pipe 333k provided in the apparatus main body 300A. A screw (not shown) is disposed inside the toner transport pipe 333k, and the screw is driven by a drive unit 334k. At this time, the screw transports toner from the toner cartridge 331k toward the process cartridge 30k in the direction D3, thereby replenishing the toner to the process cartridge 30k. The direction D3 is the direction from the toner cartridge 331k located upstream of the intermediate transfer belt 8 in the transport direction D1 toward the process cartridge 30k located downstream, and is preferably substantially parallel to the transport direction D1.

[0120] Similarly, the supply port 32r of the process cartridge 30r is connected to the discharge port of the toner cartridge 331r via a toner transport pipe 333r provided in the apparatus main body 300A. A screw (not shown) is disposed inside the toner transport pipe 333r, and the screw is driven by a drive unit 334r. At this time, the screw transports toner from the toner cartridge 331r toward the process cartridge 30r in the direction D3, thereby replenishing the toner into the process cartridge 30r.

[0121] Here, toner transport pipes 333r and 333k are set to have approximately the same transport distance and are preferably made of the same parts. Similarly, drive units 334r and 334k, and supply ports 32r and 32k are also preferably made of the same parts. Standardizing parts is expected to reduce costs and improve quality.

[0122] Furthermore, in this embodiment, when arranging the two process cartridges 30k, 30r and the two toner cartridges 331k, 331r along the intermediate transfer belt 8, the replenishment source toner cartridge and the replenishment destination process cartridge are arranged adjacent to each other. In other words, in terms of the transport direction D1 of the intermediate transfer belt 8, the black process cartridge 30k and the black toner cartridge 331k are adjacent to each other, and the customized color process cartridge 30r and the customized color toner cartridge 331r are adjacent to each other. This shortens the toner replenishment path compared to other arrangements, making it possible to reduce costs by miniaturizing parts and to make effective use of the space below the intermediate transfer belt 8.

[0123] The toner transport pipe 333k for transporting black toner extends from the upstream side to the downstream side in the belt movement direction (D1) and functions as a first transport pipe for transporting the first toner from the first toner cartridge to the first process cartridge. The toner transport pipe 333r for transporting customized toner extends from the upstream side to the downstream side in the belt movement direction (D1) and functions as a second transport pipe for transporting the second toner from the second toner cartridge to the second process cartridge.

[0124] When viewed in the belt movement direction (D1), the toner transport pipes 333r and 333k overlap each other. This arrangement allows the toner supply configuration to be compactly arranged when two sets of toner cartridges and process cartridges are arranged adjacent to each other.

[0125] (Toner replacement and scanner unit) 20 is a diagram illustrating the toner replacement procedure and the arrangement of the scanner unit in this embodiment. The toner cartridge 331k is positioned relative to the apparatus main body 300A by a cartridge rail 336k, and during toner replacement, it is inserted or removed in the direction D4 along the cartridge rail 336k. Similarly, the toner cartridge 331r is inserted or removed in the direction D4 along the cartridge rail 336r. The D4 direction is a direction intersecting the transport direction D1 of the intermediate transfer belt 8, and preferably is a direction approximately parallel to the main scanning direction (the direction of the rotation axis of the photosensitive drum) during image formation, which is perpendicular to the transport direction D1.

[0126] The scanner unit 4 irradiates the process cartridges 30r and 30k with laser light to write electrostatic latent images on the surfaces of the photosensitive drums. At this time, the laser light is irradiated onto the process cartridge 30r through the dustproof glass 304r, and onto the process cartridge 30k through the dustproof glass 304k. Therefore, the scanner unit 4 is disposed so as to straddle the process cartridges 30r and 30k and the toner cartridges 331r and 331k. Therefore, the scanner unit 4 can be the same as the scanner unit 4 (equipped with four dustproof glasses 304k) in the color image forming apparatus 1C (FIG. 10(b)), for example.

[0127] In this embodiment, the scanner unit 4 is disposed below the process cartridges 30r and 30k, and the process cartridges 30r, 30k, and the transfer unit are disposed in this order along the transport direction D1 of the intermediate transfer belt 8. Therefore, compared to when the scanner unit is disposed above the process cartridges, the distance over which the toner images of the process cartridges 30r and 30k reach the transfer unit can be shortened. In other words, in a configuration in which the process cartridges 30r and 30k and the scanner unit 4 are disposed above the intermediate transfer belt 8 (see, for example, FIG. 9 ), the toner image transferred to the upper tensioning portion of the intermediate transfer belt 8 reaches the transfer unit via the lower tensioning portion. The upper tensioning portion is a portion stretched above at least two rollers that stretch the intermediate transfer belt 8, and the lower tensioning portion is a portion stretched below at least two rollers. Compared to the configuration in FIG. 9 , in this embodiment, the toner image transferred to the lower tensioning portion of the intermediate transfer belt 8 reaches the transfer unit directly. In other words, the toner image reaches the transfer unit more quickly, which allows for a shorter FPOT.

[0128] The above-described advantage of a shorter FPOT also applies to other embodiments (FIGS. 1, 10, etc.) in which the process cartridges 30r, 30k and the scanner unit 4 are disposed below the intermediate transfer belt 8. Furthermore, in this embodiment, an image forming apparatus is used that is configured so that the sheet S is transported from below to above in the transfer section (so-called vertical transport type), but if the configuration of the transport path within the image forming apparatus is different, the arrangement of the process cartridges and scanner unit will also be changed. [Example]

[0129] An image forming apparatus 300 according to Example 6 will be described. Fig. 21 is a schematic diagram of the image forming apparatus 300 according to this example. Hereinafter, elements with the same reference numerals as those in Example 1 will be described as having substantially the same configurations and functions as those in Example 1.

[0130] Like the image forming apparatus 1 of the first embodiment, the image forming apparatus 300 of this embodiment can also be combined with a post-processing device 6 (FIG. 1) that performs binding processing on sheets S to configure an image forming system 1S. In this case, the sheets S discharged from the pair of discharge rollers 21 are delivered to the post-processing device 6, temporarily stacked in the binding device 25 in the post-processing device 6, subjected to binding processing, and then discharged as a sheet bundle to the discharge tray of the post-processing device 6.

[0131] (Outline of image forming device) The image forming apparatus 300 is an electrophotographic apparatus equipped with an electrophotographic image forming unit 1B inside an apparatus main body 300A. The image forming unit 1B includes an intermediate transfer belt 8 as an intermediate transfer member, and process cartridges 30r and 30k arranged along the intermediate transfer belt 8. Each of the process cartridges 30r and 30k is detachably attached to the apparatus main body 300A. The process cartridge 30k is a first process cartridge (first cartridge) that forms an image using a first toner, and the process cartridge 30r is a second process cartridge (second cartridge) that forms an image using a second toner.

[0132] Here, the process cartridge 30k receives toner supply from the toner cartridge 331k, and the process cartridge 30r receives toner supply from the toner cartridge 331r.

[0133] (Cartridge placement) The process cartridges 30r and 30k are arranged along the intermediate transfer belt 8. The toner cartridge 331r, the toner cartridge 331k, the process cartridge 30r, and the process cartridge 30k are lined up in this order along the transport direction D1 of the intermediate transfer belt 8. In other words, this embodiment has a configuration in which the second toner cartridge, the first toner cartridge, the second process cartridge, the first process cartridge, and the transfer unit are lined up in this order in the movement direction of the intermediate transfer belt 8.

[0134] The process cartridge 30k creates a toner image using black toner, while the process cartridge 30r creates a toner image using customized toner. The customized toner is a toner of a customized color such as red, blue, or clear (a colored toner other than black or a transparent toner), and is changed as appropriate depending on the user's usage pattern. Furthermore, by using adhesive toner, the process cartridge 30r and the toner cartridge 331r can bind sheets using the same binding device 25 as in the first embodiment. In other words, the process cartridge 30r can also be suitably used as a custom process cartridge that uses a toner different from the toner mainly used to record images on sheets.

[0135] Here, the "device main body 300A" of the image forming device 300 refers to the portion of the image forming device 300 excluding the process cartridges 30r, 30k and the toner cartridges 331r, 331k. The device main body 300A includes frame members such as a metal frame that constitute the frame of the image forming device 300 and members fixed to the frame, and forms an installation space into which the process cartridges 30r, 30k and the toner cartridges 331r, 331k are installed.

[0136] As described above, in this embodiment as well, the toner cartridges 331r, 331k and the process cartridges 30r, 30k are arranged side by side along the intermediate transfer belt 8. That is, as shown in Fig. 21, the toner cartridges 331r, 331k are each mounted at a position overlapping the process cartridges 30r, 30k when viewed in the transport direction D1 of the intermediate transfer belt 8 between the tension roller 10 and the photosensitive drum 2k. In other words, the first toner cartridge and the second toner cartridge in this embodiment are each mounted at a position overlapping the first process cartridge and the second process cartridge when viewed in the belt movement direction between the tension roller and the first image carrier.

[0137] In terms of their positional relationship with the scanner unit 4, the toner cartridges 331r and 331k are mounted between the scanner unit 4 and the intermediate transfer belt 8 in the orthogonal direction Dv of the intermediate transfer belt 8. When viewed in the orthogonal direction Dv, the toner cartridges 331r and 331k at least partially overlap the intermediate transfer belt 8 and the scanner unit 4. The orthogonal direction Dv is a direction orthogonal to the transport direction D1 of the intermediate transfer belt 8 when viewed in the main scanning direction (the direction of the rotation axis of the photosensitive drum 2k) during image formation (particularly, a direction orthogonal to the transport direction D1 at the contact position with the photosensitive drum 2k).

[0138] That is, when viewed in the direction of the rotation axis of the first image carrier (photosensitive drum 2k), the exposure unit of this embodiment is disposed at a position where the first process cartridge and the second process cartridge are sandwiched between the exposure unit and the belt in the orthogonal direction (Dv) perpendicular to the belt movement direction (D1) at the contact portion with the first image carrier. Furthermore, when viewed in the direction of the rotation axis of the first image carrier, the first toner cartridge and the second toner cartridge of this embodiment are disposed on the same side of the belt as the first process cartridge and the second process cartridge in the orthogonal direction (Dv), and on the same side of the exposure unit as the first process cartridge and the second process cartridge in the orthogonal direction (Dv). This configuration makes it possible to realize the configuration of an image forming apparatus 300 that utilizes a device main body common to the color image forming apparatus 1C.

[0139] 21 in relation to the conveying direction D1. In other words, the toner cartridges 331r and 331k may be arranged so that they do not necessarily overlap with the scanner unit 4 and the intermediate transfer belt 8 when viewed in the orthogonal direction Dv. Furthermore, when an LED exposure unit is used as the exposure unit, for example, the toner cartridge 31 does not need to be arranged between the exposure unit and the intermediate transfer belt 8 in relation to the orthogonal direction Dv.

[0140] (Toner supply path) Next, the toner supply configuration of the process cartridges 30r and 30k will be described with reference to Figure 22. Figure 22 is a perspective view for explaining the toner supply path, showing the state as seen from the rear side of the image forming apparatus 300 (the far side in Figure 21).

[0141] The supply port 32k of the process cartridge 30k is connected to the discharge port of the toner cartridge 331k via a toner transport pipe 333k provided in the apparatus main body 300A. A screw (not shown) is disposed inside the toner transport pipe 333k, and the screw is driven by a drive unit 334k. At this time, the screw transports toner from the toner cartridge 331k toward the process cartridge 30k in the direction D3, thereby replenishing the toner to the process cartridge 30k. The direction D3 is the direction from the upstream side to the downstream side of the transport direction D1 of the intermediate transfer belt 8, and is preferably substantially parallel to the transport direction D1.

[0142] Similarly, the supply port 32r of the process cartridge 30r is connected to the discharge port of the toner cartridge 331r via a toner transport pipe 333r provided in the apparatus main body 300A. A screw (not shown) is disposed inside the toner transport pipe 333r, and the screw is driven by a drive unit 334r. At this time, the screw transports toner from the toner cartridge 331r toward the process cartridge 30r in the direction D3, thereby replenishing the toner into the process cartridge 30r.

[0143] Note that toner transport pipe 333r is located behind toner transport pipe 333k (at the rear in FIG. 33) and is disposed substantially parallel to toner transport pipe 333k. Therefore, toner transported in the D3 direction changes direction upward and is then transported in the D5 direction to reach supply port 32r. The D5 direction intersects with the D3 direction and the up-down direction (vertical direction), and is preferably substantially parallel to the main scanning direction (the direction of the rotation axis of the photosensitive drum) during image formation.

[0144] (Toner replacement and scanner unit) 23 is a diagram illustrating the toner replacement procedure and the arrangement of the scanner unit in this embodiment. The toner cartridge 331k is positioned relative to the apparatus main body 300A by a cartridge rail 336k, and during toner replacement, it is inserted or removed in the direction D4 along the cartridge rail 336k. Similarly, the toner cartridge 331r is inserted or removed in the direction D4 along the cartridge rail 336r. The D4 direction is a direction intersecting the transport direction D1 of the intermediate transfer belt 8, and preferably is a direction approximately parallel to the main scanning direction (the direction of the rotation axis of the photosensitive drum) during image formation, which is perpendicular to the transport direction D1.

[0145] The scanner unit 4 irradiates the process cartridges 30r and 30k with laser light to write electrostatic latent images on the surfaces of the photosensitive drums. At this time, the laser light is irradiated onto the process cartridge 30r from the dustproof glass 304r, and onto the process cartridge 30k from the dustproof glass 304k. Therefore, the scanner unit 4 can be the same as the scanner unit 4 (equipped with four dustproof glasses 304k) in the color image forming apparatus 1C (FIG. 10(b)), for example.

[0146] In this embodiment, the two toner cartridges 331r, 331k are disposed upstream of the two process cartridges 30k, 30r in the transport direction D1 of the intermediate transfer belt 8, and are therefore farther away from the transfer unit and the fixing device 18. For example, compared to the embodiment of FIG. 18, the distance between the toner cartridge 331k and the fixing device 18 is greater. This makes it possible to reduce the effect of heat generated by the fixing device 18, which is a heat source, on the toner contained in the toner cartridges 331r, 331k, and to suppress a decrease in productivity due to an increase in temperature inside the machine, for example.

[0147] The toner transport pipe 333k for transporting black toner extends from the upstream side to the downstream side in the belt movement direction (D1) and functions as a first transport pipe for transporting the first toner from the first toner cartridge to the first process cartridge. The toner transport pipe 333r for transporting customized toner extends from the upstream side to the downstream side in the belt movement direction (D1) and functions as a second transport pipe for transporting the second toner from the second toner cartridge to the second process cartridge.

[0148] When viewed in the main scanning direction Dm (the direction of the rotation axis of the photosensitive drum 2k) during image formation, the toner conveying pipes 333r and 333k overlap each other. This allows customized toner (second toner) discharged from the toner cartridge 331r to be replenished to the process cartridge 30r located across the toner cartridge 331k containing black toner (first toner) in the belt movement direction (D1). Also, black toner (first toner) discharged from the toner cartridge 331k can be replenished to the process cartridge 30k located across the process cartridge 30r containing customized toner (second toner) in the belt movement direction (D1).

[0149] (Other embodiments) In the above-mentioned Examples 1 to 6, an image forming system was described in which the binding processing device 25 was arranged outside the image forming device 1,100, but the image forming system may also be in a form in which the binding processing device 25 is incorporated into the image forming device 1,100. [Explanation of symbols]

[0150] 1S...image forming system / 1,100...image forming apparatus / 1A,100A...apparatus main body / 2k,102k...first image carrier (photosensitive drum) / 2s,102s...second image carrier (photosensitive drum) / 8...intermediate transfer belt / 11...transfer member (secondary transfer roller) / 30k,130k...first process cartridge / 30s,30r,130s...second process cartridge / 31,131...toner cartridge / 32...supply port / 107k,107s...transfer member (transfer roller) / 108...conveyor belt (electrostatic adsorption belt) / 331k...first toner cartridge / 331r...second toner cartridge

Claims

1. A device body, a process cartridge detachably attached to the main body of the apparatus, the process cartridge having an image carrier and a developing roller for supplying toner to the image carrier; a toner cartridge that is detachably mounted to the apparatus main body independently of the process cartridge and that contains toner to be replenished to the process cartridge; a movable endless belt whose outer surface is in contact with the image carrier and onto which a toner image is transferred from the image carrier; a transfer member that contacts the outer surface of the belt to form a transfer portion and transfers the toner image transferred to the belt onto a recording material at the transfer portion; a tension roller that contacts the inner surface of the belt downstream of the transfer unit and upstream of the image carrier in the rotation direction of the belt and stretches the belt; and The image forming apparatus is characterized in that the toner cartridge is located at a position overlapping the process cartridge when viewed in the direction of movement of the belt between the tension roller and the image carrier.

2. 2. The image forming apparatus according to claim 1, wherein the toner cartridge, the process cartridge, and the transfer unit are arranged in this order in the direction of movement of the belt.

3. An image forming apparatus as described in claim 1 or 2, characterized in that, when viewed in the direction of the rotation axis of the image carrier, the width of the toner cartridge in the direction of movement of the belt is larger than the width of the process cartridge in the direction of movement of the belt, and is less than three times the width of the process cartridge.

4. the toner cartridge further includes another toner cartridge that contains the same toner as the toner cartridge, is detachable from the device main body independently of the process cartridge and the toner cartridge, and replenishes the toner to the process cartridge; 3. An image forming apparatus according to claim 1, wherein the other toner cartridge is mounted in a position overlapping the process cartridge and the toner cartridge when viewed in the direction of movement of the belt between the tension roller and the image carrier.

5. an exposure unit that exposes the image carrier; the exposure unit is disposed so that the process cartridge is located between the exposure unit and the belt in a direction perpendicular to both the moving direction of the belt and the direction of the rotation axis of the developing roller; 5. An image forming apparatus according to claim 1, wherein the toner cartridge is arranged on the same side of the belt as the process cartridge in the perpendicular direction, and on the same side of the exposure unit as the process cartridge in the perpendicular direction.

6. 6. The image forming apparatus according to claim 5, wherein the toner cartridge is disposed at a position overlapping the belt and the exposure unit when viewed in the orthogonal direction.

7. 7. The image forming apparatus according to claim 1, wherein the toner cartridge has a collection container for collecting waste toner removed from the belt.

8. 8. The image forming apparatus according to claim 7, wherein the toner cartridge includes a cleaning member that removes waste toner from the belt and collects the waste toner in the collection container.

9. A device body, a first process cartridge detachably mounted to the main body of the apparatus, the first process cartridge having a first image carrier and a first developing roller for supplying a first toner to the first image carrier; a first toner cartridge that is detachably mountable to the apparatus main body independently of the first process cartridge and that contains the first toner; a second process cartridge detachably mounted to the main body of the apparatus, the second process cartridge having a second image carrier and a second developing roller for supplying a second toner to the second image carrier; a second toner cartridge that is detachably mountable to the apparatus main body independently of the second process cartridge and that contains the second toner; a movable endless belt whose outer surface is in contact with the first image carrier and the second image carrier, and onto which the toner images are transferred from the first image carrier and the second image carrier; a transfer member that contacts the outer surface of the belt to form a transfer portion and transfers the toner image transferred to the belt onto a recording material at the transfer portion; a tension roller that contacts the inner surface of the belt downstream of the transfer portion and upstream of the first image carrier and the second image carrier in the rotation direction of the belt and stretches the belt; and An image forming apparatus characterized in that each of the first toner cartridge and the second toner cartridge is installed in a position that overlaps with the first process cartridge and the second process cartridge when viewed in the direction of movement of the belt between the tension roller and the first image carrier.

10. 10. The image forming apparatus according to claim 9, wherein the second toner cartridge, the second process cartridge, the first toner cartridge, the first process cartridge, and the transfer unit are arranged in this order in the direction of movement of the belt.

11. a first conveying pipe extending from an upstream side to a downstream side in the moving direction of the belt and conveying the first toner from the first toner cartridge to the first process cartridge; a second conveying pipe extending from the upstream side to the downstream side in the moving direction of the belt to convey the second toner from the second toner cartridge to the second process cartridge; and 11. The image forming apparatus according to claim 10, wherein the first conveying pipe and the second conveying pipe overlap each other when viewed in the moving direction of the belt.

12. 10. The image forming apparatus according to claim 9, wherein the second toner cartridge, the first toner cartridge, the second process cartridge, the first process cartridge, and the transfer unit are arranged in this order in the direction of movement of the belt.

13. a first conveying pipe extending from an upstream side to a downstream side in the moving direction of the belt and conveying the first toner from the first toner cartridge to the first process cartridge; a second conveying pipe extending from the upstream side to the downstream side in the moving direction of the belt to convey the second toner from the second toner cartridge to the second process cartridge; and 13. The image forming apparatus according to claim 12, wherein the first conveying pipe and the second conveying pipe overlap each other when viewed in the direction of the rotation axis of the first image carrier.

14. the first toner is a color toner, and the second toner is a powder adhesive; 14. The image forming apparatus according to claim 9, wherein the image forming apparatus is a recording medium.

15. the first toner is a black toner, and the second toner is a color toner other than black or a transparent toner; 14. The image forming apparatus according to claim 9, wherein the image forming apparatus is a recording medium.

16. an image forming apparatus according to claim 14 or 15; a binding processing device that binds a plurality of sheets on which images have been formed by the image forming device using the second toner by heating the sheets; An image forming system comprising:

Images