Image forming apparatus

Abstract

To carry out a change from a full specification state to a specific specification state or a change from the specific specification state to the full specification state.SOLUTION: An inner cover 50 for full specifications allows air supply from all of a plurality of air inlets C1-C4 to all of a plurality of stations X1-X4, and allows removable attachment of a plurality of image forming units 10Y, 10M, 10C, 10K to the plurality of stations X1-X4, and is installed in the body of an image forming apparatus 1 when image formation is performed in a full specification state. An inner cover 51 for specific specifications allows air supply only from an inlets C4 corresponding to a use station X4 to the use station X4, and allows removable attachment of only an image forming units 10K to the use station X4, and is installed in the body of an image forming apparatus 1 when image formation is performed in a specific specification state.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile machine, or a combination machine thereof. [Background technology]

[0002] Conventionally, there have been known image forming devices such as copiers and printers that can perform image formation (printing) by installing only one imaging unit in a space where multiple imaging units can be installed, with no other imaging units installed (see, for example, Patent Document 1).

[0003] On the other hand, Patent Document 1 discloses a technology in which only one imaging unit for black is installed in a space that can accommodate four imaging units (image-making units), and when printing, a shielding member is installed between the space and the cooling fan, and air is exhausted from between the cooling fan and the shielding member through an air passage that is provided to communicate with the lower part of the space. Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional technology, when changing from a full specification state in which multiple imaging units are all installed in multiple stations to a specific specification state in which some of the multiple stations are used stations with imaging units installed and some are unused stations without imaging units installed, it is necessary to make modifications deep inside the image forming apparatus body, which is not an easy task.

[0005] To solve the above-mentioned problems, the present invention provides an image forming apparatus that can easily change from a full-spec state to a specific-spec state and from a specific-spec state to a full-spec state. [Means for solving the problem]

[0006] The image forming apparatus of this invention comprises a plurality of stations to which a plurality of imaging units can be attached or detached, a plurality of air inlets that allow air to be supplied to each of the plurality of stations, an air inlet duct that allows air taken in from outside the image forming apparatus body to flow toward the plurality of air inlets, a full-spec inner cover that is installed on the image forming apparatus body when image formation is performed in a full-spec state in which all of the plurality of imaging units are installed in the plurality of stations, and allows air to be supplied to all of the plurality of stations from all of the plurality of air inlets and allows each of the plurality of imaging units to be attached or detached to the plurality of stations, and a specific-spec inner cover that is installed on the image forming apparatus body when image formation is performed in a specific-spec state in which there are used stations in which the imaging units are installed and unused stations in which the imaging units are not installed, and allows air to be supplied to the used stations from the air inlets of the plurality of air inlets that correspond to the used stations, and prevents air from being supplied to the unused stations through other air inlets, and allows only the imaging units to be attached or detached to the used stations. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an image forming apparatus that can easily change from a full specification state to a specific specification state and from a specific specification state to a full specification state. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an overall configuration diagram showing an image forming apparatus according to an embodiment of the present invention; [Figure 2] FIG. 2 is a diagram illustrating the configuration of an imaging unit. [Figure 3]1A is a top view showing the air flow in an image forming apparatus in a full-spec state, and FIG. 1B is a top view showing the air flow in an image forming apparatus in a specific-spec state. [Figure 4] 1A is a perspective view showing an image forming apparatus in a full specification state with the exterior cover open, and FIG. 1B is a perspective view showing an image forming apparatus in a specific specification state with the exterior cover open. [Figure 5] FIG. 10 is a top view showing the air flow in an image forming apparatus in a specific specification state as a comparative example. [Figure 6] FIG. 10 is a side view showing the air flow in the image forming apparatus in a specific specification state. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals, and redundant explanations will be appropriately simplified or omitted.

[0010] First, the overall configuration and operation of an image forming apparatus 1 will be described with reference to FIG. In Figure 1, 1 indicates a color copier as an image forming device, 3 indicates a document transport unit that transports a document to a document reading unit 4, 4 indicates a document reading unit that reads image information of the document, and 6 indicates a writing unit (exposure unit) that emits laser light based on input image information. Also, 7 denotes a paper feed device in which sheets P such as paper are stored, 10Y, 10M, 10C, and 10K denote image-forming units corresponding to each color (yellow, magenta, cyan, and black), 17 denotes an intermediate transfer belt onto which toner images of multiple colors are transferred in layers, and 18 denotes a secondary transfer roller that transfers the toner image formed on the intermediate transfer belt 17 onto the sheet P. Also, 20 indicates a fixing device that fixes unfixed images on sheet P, 28 indicates a toner container for replenishing toner of each color to the developing devices of each image-forming unit 10Y, 10M, 10C, and 10K (process cartridge), and 30 indicates a waste toner collection container in which waste toner is collected.

[0011] Here, each of the imaging units 10Y, 10M, 10C, and 10K (process cartridges) integrates a photosensitive drum 11 as an image carrier, a charging device 12, a developing device 13, and a cleaning device 15 (see FIG. 2). When each of the imaging units 10Y, 10M, 10C, and 10K reaches the end of its life, it is replaced with a new one. On the photosensitive drums 11 (image carriers) of the imaging units 10Y, 10M, 10C, and 10K, toner images of the respective colors (yellow, magenta, cyan, and black) are formed.

[0012] Hereinafter, the operation of the image forming apparatus during normal color image formation will be described. First, the document is transported from the document table by the transport rollers of the document transport unit 3 and placed on the contact glass of the document reading unit 4. Then, the document reading unit 4 optically reads the image information of the document placed on the contact glass. The image information for each color, yellow, magenta, cyan, and black, is then sent to the writing unit 6. Then, laser light (exposure light) based on the image information for each color is emitted from the writing unit 6 toward the photosensitive drums 11 of the corresponding imaging units 10Y, 10M, 10C, and 10K.

[0013] Meanwhile, each of the four photosensitive drums 11 rotates clockwise in FIGS. 1 and 2. Referring to FIG. 2, first, the surface of each photosensitive drum 11 is uniformly charged at a position facing the charging device 12 (charging roller) (charging process). In this way, a charging potential is formed on each photosensitive drum 11. Thereafter, the charged surface of each photosensitive drum 11 reaches the irradiation position of the respective laser beam. In the writing unit 6, a laser beam L corresponding to each color of an image signal is emitted from a light source. After being incident on and reflected by a polygon mirror, the laser beam L passes through multiple lenses. After passing through the multiple lenses, the laser beam passes through separate optical paths for each color component: yellow, magenta, cyan, and black (this is the exposure process).

[0014] The laser light corresponding to the yellow component is irradiated onto the surface of the photosensitive drum 11 of the first imaging unit 10Y from the left side of the drawing. In this way, an electrostatic latent image corresponding to the yellow component is formed on the photosensitive drum 11 after it has been charged by the charging device 12. Similarly, the cyan laser beam is irradiated onto the surface of the photosensitive drum 11 of the imaging unit 10C, which is the second from the left, to form an electrostatic latent image of the cyan component. The magenta laser beam is irradiated onto the surface of the photosensitive drum 11 of the imaging unit 10M, which is the third from the left, to form an electrostatic latent image of the magenta component. The black laser beam is irradiated onto the surface of the photosensitive drum 11 of the imaging unit 10K, which is the fourth from the left, to form an electrostatic latent image of the black component.

[0015] Thereafter, the surface of the photosensitive drum 11 on which the electrostatic latent image of each color is formed reaches a position facing the developing device 13 (see FIG. 2). Then, toner of each color is supplied from each developing device 13 onto the photosensitive drum 11, and the latent image on the photosensitive drum 11 is developed (this is the developing process). Thereafter, the surfaces of the photosensitive drums 11 after the development process reach positions facing an intermediate transfer belt 17 (intermediate transfer body) serving as an image carrier. Here, primary transfer rollers 14 are installed at each facing position so as to abut against the inner circumferential surface of the intermediate transfer belt 17. Then, at the positions of the primary transfer rollers 14, the toner images of each color formed on the photosensitive drums 11 are transferred onto the intermediate transfer belt 17 in order, superimposed on top of each other (this is the primary transfer process).

[0016] After the primary transfer step, the surfaces of the photosensitive drums 11 reach a position facing the cleaning devices 15 (see FIG. 2). The cleaning devices 15 then collect untransferred toner remaining on the photosensitive drums 11 (this is the cleaning step). Thereafter, the surface of the photosensitive drum 11 passes the position of the charge eliminating device, and a series of image forming processes on the photosensitive drum 11 is completed.

[0017] Meanwhile, the surface of the intermediate transfer belt 17 onto which the images of each color on the photosensitive drum 11 are transferred and superimposed runs in the direction of the arrow in Fig. 1 and reaches the position of the secondary transfer roller 18. Then, at the position of the secondary transfer roller 18, the full-color image on the intermediate transfer belt 17 is secondarily transferred onto the sheet P (secondary transfer process). Thereafter, the surface of the intermediate transfer belt 17 reaches the position of the intermediate transfer belt cleaning device 9 (cleaning device). Then, the untransferred toner on the intermediate transfer belt 17 is collected by the intermediate transfer belt cleaning device 9, and the series of transfer processes on the intermediate transfer belt 17 is completed.

[0018] Here, the sheet P at the position of the secondary transfer roller 18 is conveyed from the paper feeder 7 via a conveyance guide, registration rollers 19, and the like. More specifically, the sheet P fed by the sheet feed roller 8 from the sheet feed device 7 storing the sheet P passes through a conveyance guide and is then guided to the registration roller 19. The sheet P that has reached the registration roller 19 is conveyed toward the position of the secondary transfer roller 18 in synchronization with the toner image on the intermediate transfer belt 17.

[0019] Thereafter, the sheet P onto which the full-color image has been transferred is guided to the fixing device 20. In the fixing device 20, the color image is fixed onto the sheet P at the nip between a fixing roller and a pressure roller. After the fixing process, the sheet P is discharged as an output image outside the apparatus main body 1 by a discharge roller 29, and then stacked on the discharge section 5, completing a series of image forming processes.

[0020] Next, the image forming unit of the image forming apparatus will be described in detail with reference to FIG. 2 is a configuration diagram showing the black imaging unit 10K. The other three imaging units 10Y, 10M, and 10C are configured almost identically to the black imaging unit 10K, except for the different colors of toner used in the image creation process, and therefore will not be shown or described here.

[0021] As shown in FIG. 2, the imaging unit 10K includes a photosensitive drum 11 as an image carrier, a charging device 12 that charges the photosensitive drum 11, a developing device 13 that develops the electrostatic latent image formed on the photosensitive drum 11, and a cleaning device 15 that collects untransferred toner on the photosensitive drum 11, all housed in a case.

[0022] Here, the photosensitive drum 11 is a negatively charged organic photosensitive body, and is formed by providing a photosensitive layer on a drum-shaped conductive support. The charging device 12 is a charging roller made of a conductive core metal and a medium-resistance elastic layer coated on the outer periphery thereof. A predetermined voltage is applied to the charging device 12 (charging roller) from a power supply unit, thereby uniformly charging the surface of the opposing photosensitive drum 11.

[0023] The developing device 13 is mainly composed of a developing roller 13a facing the photosensitive drum 11, a first transport screw 13b1 facing the developing roller 13a, a second transport screw 13b2 facing the first transport screw 13b1 via a partition member, and a doctor blade 13c facing the developing roller 13a. The developing roller 13a is composed of a magnet that is fixed inside and forms magnetic poles on the roller's circumferential surface, and a sleeve that rotates around the magnet. The magnet forms multiple magnetic poles on the developing roller 13a (sleeve), and developer is carried on the developing roller 13a. The developing device 13 contains a two-component developer made up of a carrier and a toner.

[0024] The cleaning device 15 is equipped with a cleaning blade 15a that contacts the photosensitive drum 11, a transport screw 15b (transport pipe 16) that transports the untransferred toner collected in the cleaning device 15 as waste toner toward a waste toner transport device (not shown), and other components. The cleaning blade 15a is made of a rubber material such as urethane rubber and contacts the surface of the photosensitive drum 11 at a predetermined angle and with a predetermined pressure. This mechanically scrapes off untransferred toner and other deposits adhering to the photosensitive drum 11 and collects them in the cleaning device 15. The untransferred toner collected in the cleaning device 15 is then transported to the waste toner transport device (not shown) via the transport pipe 16 (in which the transport screw 15b is installed), and is further transported by the waste toner transport device to the waste toner collection container 30, where it is collected as waste toner. In addition to untransferred toner, other deposits that may adhere to the photosensitive drum 11 or intermediate transfer belt 17 include paper dust generated from the sheet P (paper), discharge products generated on the photosensitive drum 11 when the charging device 12 discharges, additives added to the toner, etc., but in this application these will be collectively referred to as "untransferred toner."

[0025] FIG. 2 illustrates the imaging process described above in more detail. Developing roller 13a rotates in the direction of the arrow (counterclockwise) in Fig. 2. Due to the rotation of first transport screw 13b1 and second transport screw 13b2, which are arranged with a partition member interposed therebetween, the developer in developing device 13 is circulated in the longitudinal direction (the direction perpendicular to the plane of Fig. 2) while being stirred and mixed with toner replenished from toner container 28 by a toner replenishment device (not shown).

[0026] The toner that has been frictionally charged and attracted to the carrier is then carried on the developing roller 13a together with the carrier. The developer carried on the developing roller 13a then reaches the position of the doctor blade 13c. The amount of developer on the developing roller 13a is adjusted to an appropriate amount at the position of the doctor blade 13c, and then reaches a position facing the photosensitive drum 11 (the developing area). Thereafter, in the development area, the toner in the developer adheres to the electrostatic latent image formed on the surface of the photosensitive drum 11. More specifically, the toner adheres to the latent image (a toner image is formed) due to an electric field formed by a potential difference (development potential) between the latent image potential (exposure potential) of the image portion irradiated with the laser light L and the development bias applied to the development roller 13a. Thereafter, in the developing process, most of the toner adhering to the photosensitive drum 11 is transferred onto the intermediate transfer belt 17. Then, the untransferred toner remaining on the photosensitive drum 11 is collected into the cleaning device 15 by the cleaning blade 15a.

[0027] The characteristic configuration and operation of the image forming apparatus 1 according to this embodiment will be described in detail below. 1 and the like, a plurality of imaging units 10Y, 10M, 10C, and 10K are detachably installed in the image forming apparatus 1. Specifically, the plurality of imaging units is four in total: one black imaging unit 10K and three color imaging units 10Y, 10M, and 10C. 3(A), 4(A), etc., image forming apparatus 1 is provided with a plurality of stations X1 to X4 (installation sections) to which a plurality of imaging units 10Y, 10M, 10C, and 10K can be attached or detached. Specifically, four imaging units 10Y, 10M, 10C, and 10K are attached or detached to or from the four stations X1 to X4, respectively. When imaging units 10Y, 10M, 10C, and 10K are not installed in these four stations X1 to X4, the corresponding areas become completely open spaces.

[0028] 3(A), the image forming apparatus 1 is formed with a flow path that allows air (outside air) taken in from the outside through an inlet A to flow into the image forming apparatus main body 1 and then discharges the air to the outside of the image forming apparatus main body 1 through an outlet B. That is, an air (gas) flow path is formed in the image forming apparatus 1 as shown by the black arrow in FIG. This flow path is mainly for cooling the imaging units 10Y, 10M, 10C, and 10K.

[0029] The image forming apparatus 1 (flow path) is provided with a plurality of (four) air intake ports C1 to C4, an air intake duct 41, an air intake fan 45, and the like. The plurality of air supply ports C1 to C4 enable air to be supplied to the plurality of stations X1 to X4, respectively. Air supply duct 41 is for allowing air taken in from the outside of image forming apparatus main body 1 through inlet A to flow toward the plurality of air supply ports C1 to C4. Specifically, in this embodiment, four air intake ports C1 to C4 are formed in the air intake duct 41 at positions facing the front side (the lower side in Figure 3(A), the front side in the direction perpendicular to the paper surface of Figure 1) of the four imaging units 10Y, 10M, 10C, and 10K. Additionally, air supply duct 41 is provided with air supply fan 45 on the upstream side (on the right side in FIG. 3(A)) of the air flow direction relative to the multiple air supply ports C1 to C4. When air supply fan 45 is driven, outside air is actively taken into air supply duct 41 from inlet port A.

[0030] Now, referring to FIG. 4(A), in this embodiment, an exterior cover 60 (opening / closing cover) that can open the inside of the image forming apparatus 1 is provided on the front side of the image forming apparatus main body 1 (the front side where an operator such as a user performs main operations). When the exterior cover 60 is in an open state (the state shown in FIG. 4A), the full-spec inner cover 50 (inner cover) is exposed, and has insertion openings 50Y, 50M, 50C, and 50K formed therein for attaching and detaching the imaging units 10Y, 10M, 10C, and 10K. In this embodiment, an air intake duct 41 (which moves as the exterior cover 60 is opened and closed) is provided inside the exterior cover 60. When the exterior cover 60 is closed, the multiple air intake openings C1 to C4 of the air intake duct 41 face the openings of the imaging units 10Y, 10M, 10C, and 10K via the insertion openings 50Y, 50M, 50C, and 50K of the full-spec inner cover 50. The positional relationship between the inner cover 50, the air supply duct 41, and the stations X1 to X4 is not limited to that shown in FIG. 3(A) and the like.

[0031] 3A, the plurality of exhaust ports D1 to D4 enable exhaust from each of the imaging units 10Y, 10M, 10C, and 10K installed in the plurality of stations X1 to X4. The air exhausted from the plurality of exhaust ports D1 to D4 is discharged to the outside of the image forming apparatus main body 1 through the outlet B. Specifically, in this embodiment, four exhaust ports D1 to D4 are formed on the rear side (upper side in Figure 3(A), and on the back side in the direction perpendicular to the paper surface of Figure 1) of the four imaging units 10Y, 10M, 10C, and 10K, respectively.

[0032] In this embodiment, air that flows into stations X1 to X4 from air intake ports C1 to C4 passes through the interiors of imaging units 10Y, 10M, 10C, and 10K installed in stations X1 to X4 (mainly the space W surrounded by the dashed line in FIG. 2) and is exhausted from exhaust ports D1 to D4. That is, air escapes from the front side to the rear side within imaging units 10Y, 10M, 10C, and 10K. With this configuration, the cooling performance of the imaging units 10Y, 10M, 10C, and 10K can be improved.

[0033] Here, the image forming apparatus 1 in this embodiment is configured to be able to switch between performing image formation (printing) in a "full specification state" in which multiple (four) imaging units 10Y, 10M, 10C, and 10K are all installed in multiple (four) stations X1 to X4, as shown in Figures 1, 3(A), and 4(A), and performing image formation (printing) in a "specific specification state" in which, among the multiple (four) stations X1 to X4, there is a used station X4 in which imaging unit 10K is installed, and unused stations X1 to X3 in which imaging units 10Y, 10M, and 10C are not installed, as shown in Figures 3(B) and 4(B). In this embodiment, the "specific specification state" is a state in which monochrome image formation (monochrome printing) can be performed using only the black imaging unit 10K. Therefore, the image forming apparatus 1 of the present embodiment can be used by users as a full-color image forming apparatus using four colors (YMCK), or as a monochrome image forming apparatus using only black. This configuration reduces design and manufacturing costs compared to manufacturing a full-color image forming apparatus and a monochrome image forming apparatus separately. Furthermore, even if a user wishes to change from a full-color image forming apparatus to a monochrome image forming apparatus, or from a monochrome image forming apparatus to a full-color image forming apparatus, this can be accommodated without significant cost.

[0034] In this embodiment, as shown in FIG. 3(A), when image formation is performed in the "full spec state" (when used as a full-color image forming apparatus 1), air is supplied to all of the multiple stations X1 to X4 from all of the multiple air intakes C1 to C4. Furthermore, when image formation is performed in the "full spec state" (when used as a full-color image forming apparatus 1), the apparatus is configured so that exhaust is conducted from all of the multiple stations X1 to X4 to the exhaust duct 42 via multiple exhaust ports C1 to C4. That is, in the full-spec state, an air flow is formed as shown by the black arrows in Fig. 3(A), which, as explained above, improves the cooling performance (temperature rise prevention performance) of the imaging units 10Y, 10M, 10C, and 10K.

[0035] Here, referring to Figures 3(A), 4(A), etc., when image formation is performed in the "full-spec state" (when used as a full-color image forming apparatus 1), a full-spec inner cover 50 is installed inside the outer cover 60. This full-spec inner cover 50 is configured to allow air to be supplied to all of the multiple stations from all of the multiple air intakes C1 to C4, and to allow each of the multiple imaging units 10Y, 10M, 10C, and 10K to be attached and detached to the multiple stations X1 to X4. As explained above, the full-spec inner cover 50 has insertion openings 50Y, 50M, 50C, and 50K for attaching and detaching the imaging units 10Y, 10M, 10C, and 10K formed in such a way as not to interfere with the supply of air to the imaging units 10Y, 10M, 10C, and 10K from the air intake ports C1 to C4 of the air intake duct 41. The full-spec inner cover 50 is detachably installed on the housing of the image forming apparatus main body 1 by a relatively simple fixing method such as screwing, and can be attached and detached with the exterior cover 60 open.

[0036] In contrast, as shown in Figure 3(B), when image formation is performed in a "specific specification state" (when used as a monochrome image forming apparatus 1), air is supplied to the used station X4 (black imaging unit 10K) from the air intake C4 corresponding to the used station X4 out of the multiple (four) air intakes C1 to C4, and air is not supplied to the unused stations X1 to X3 (color imaging units 10Y, 10M, 10C) through the other air intakes C1 to C3.

[0037] Specifically, in the “special specification state” (when used as the monochrome image forming apparatus 1), the inner cover 51 for the special specification is installed inside the outer cover 60. That is, when the image forming apparatus 1 is changed from the full specification state to the specific specification state, the full specification inner cover 50 is removed and the specific specification inner cover 51 is attached. On the other hand, when the image forming apparatus 1 is changed from the specific specification state to the full specification state, the specific specification inner cover 51 is removed and the full specification inner cover 50 is attached.

[0038] This inner cover 51 for specific specifications allows air to be supplied to the used station X4 (black imaging unit 10K) from the air intake C4 corresponding to the used station X4 (black imaging unit 10K) among the multiple air intakes C1 to C4, prevents air from being supplied to the unused stations X1 to X3 through the other air intakes C1 to C4, and allows only the color imaging units 10Y, 10M, and 10C to be attached and detached to the unused stations X1 to X3. More specifically, in the specific specification state, insertion openings for attaching and detaching the color imaging units 10Y, 10M, and 10C are not necessary, and therefore only an insertion opening 51K for attaching and detaching the black imaging unit 10K is formed in the specific specification inner cover 51. Also, as explained above, the air intake duct 41 is installed inside the exterior cover 60, and when the exterior cover 60 is closed, one air intake port C4 (the air intake port corresponding to the use station X4) in the air intake duct 41 faces the opening of the black imaging unit 10K via the insertion opening 51K in the specific specification inner cover 51. The air intake duct 41 is used in common in both the full specification state and the specific specification state. Furthermore, by installing the specific specification inner cover 51 configured in this manner, it is possible to prevent the imaging units 10Y, 10M, and 10C from being mistakenly set in the unused stations X1 to X3 when in the specific specification state. In addition, the inner cover 51 for specific specifications is removably installed on the housing of the image forming apparatus main body 1 using a relatively simple fixing method such as screwing, and can be attached and removed with the outer cover 60 open.

[0039] Here, as shown in Figure 3(B), the inner cover 51 for specific specifications is provided with a partition portion 51a that functions as a blocking means for separating the unused stations X1 to X3 from the three air intake ports C1 to C3 of the air intake duct 41 by leaving a gap between them. This partition portion 51a (shielding means) is formed so that one end side (the right side in Figure 3(B)) contacts the black imaging unit 10K with almost no gap, and the upper end portion also contacts the intermediate transfer inner cover 55 (see Figures 4 and 6(A)) with almost no gap, isolating part or all of the spaces X1 to X3 in which the three color imaging units 10Y, 10M, and 10C can be installed when viewed from the front side (the side of the air intake duct 41). By configuring in this manner, of the four stations X1 to X4, air is supplied from the air intake duct 41 only to station X4 (used station) corresponding to the black imaging unit 10K, and air is not supplied from the air intake duct 41 to the other stations X1 to X3 (unused stations).

[0040] Here, in this embodiment, the partition section 51a (blocking means) is configured to allow air that has flowed into the air intake duct 41 from outside the image forming apparatus main body 1 but has not been supplied to the use station X4 (black imaging unit 10K) from the air intake port C4 corresponding to the use station X4 (black imaging unit 10K) to be exhausted directly to the side away from the multiple stations X1 to X4 (which may be outside the image forming apparatus main body 1). Therefore, when the specific specifications are met, an air flow is formed as shown by the black arrows in Figure 3(B), which improves the cooling performance (temperature rise prevention performance) of the black imaging unit 10K, as explained above.

[0041] In this way, in this embodiment, changing from the full specification state to the specific specification state, or from the specific specification state to the full specification state, can be achieved by the simple task of replacing the full specification inner cover 50 with the specific specification inner cover 51 from the front side where the operator performs operations (the lower side in Figure 3, the side where the outer cover 60 is installed).

[0042] Furthermore, as shown in FIG. 3(A), in the full specification state, a flow path is formed for each of the four imaging units 10Y, 10M, 10C, and 10K such that air passes through from the front side to the rear side, thereby enabling almost uniform cooling performance for all of the imaging units 10Y, 10M, 10C, and 10K.

[0043] As shown in Figure 3(B), in a specific specification state, a flow path is formed only for the black imaging unit 10K (used station X4) that allows air to pass from the front side to the rear side, and no such flow path is formed for the other unused stations X1 to X3.Therefore, the cooling performance for the black imaging unit 10K (used station X4) can be improved compared to when such a flow path is formed for the unused stations X1 to X3, as in the image forming apparatus 100 shown in Figure 5(A) as a comparative example.

[0044] 3B, in the specific specification state, by providing the partition 51a as described above, a portion of the outside air flowing into the air intake duct 41 is discharged to the outside of the air intake duct 41 without flowing into the three air intake ports C1 to C3. Therefore, compared to the comparative example of the image forming apparatus 200 shown in FIG. 5B, in which only the air intake port C4 corresponding to the black imaging unit 10K (used station X4) is open and the air intake ports C1 to C3 of the unused stations X1 to X3 are sealed with the sealing member 71, the amount of air supplied to the black imaging unit 10K (used station X4) is not too large but is kept appropriate. Therefore, problems such as scattering of toner generated in the developing device 13 due to an excessive amount of air are less likely to occur.

[0045] Referring to Figure 3, both the full-spec inner cover 50 and the specific-spec inner cover 51 are installed with a gap on the inner side (inside, the upper side in Figure 3) of the outer cover 60 in the image forming apparatus main body 1. More specifically, in image forming apparatus 1, air intake duct 41 and inner covers 50, 51 are not in complete contact with each other, but rather have a small gap therebetween. As a result, even if unexpected air leaks from air intake duct 41, the air can be discharged through the gap to the outside of image forming apparatus 1. This makes it possible to optimize the amount of air supplied to the imaging units without adjusting or replacing air intake fan 45.

[0046] As shown in FIG. 6, an intermediate transfer belt device having an intermediate transfer belt 17 is installed above the plurality of stations X1 to X4. As shown in Figures 4 and 6, an intermediate transfer inner cover 55 is installed on the front side (right side in Figure 6) of the image forming apparatus main body 1 so as to be sandwiched between the intermediate transfer belt device (intermediate transfer belt 17) and the outer cover 60 (see Figure 4). 6(A), in this embodiment, both the full-spec inner cover 50 and the specific-spec inner cover 51 are abutted against the intermediate transfer inner cover 55 so that no gaps are formed in the vertical direction. With this configuration, it becomes difficult for foreign matter, together with outside air, to enter the intermediate transfer belt device (intermediate transfer belt 17), as shown by the arrow in FIG. 6(B), both the full-spec inner cover 50 and the specific-spec inner cover 51 can be installed so that a gap is formed in the vertical direction relative to the intermediate transfer inner cover 55. In such a case, as shown by the arrow in FIG. 6(B), outside air can be actively taken into the intermediate transfer belt device (intermediate transfer belt 17), thereby reducing the temperature rise of the intermediate transfer belt device (intermediate transfer belt 17). In this embodiment, as shown in FIG. 6, rails 54 are provided below the stations X1 to X4 to guide the attachment and detachment of the imaging units 10Y, 10M, 10C, and 10K.

[0047] In this embodiment, the full-spec inner cover 50 and the special-spec inner cover 51 are each installed as a single component (inner cover) facing the stations X1 to X4. That is, the full-spec inner cover 50 and the special-spec inner cover 51 are each configured as a single component. On the other hand, at least one of the full-spec inner cover 50 and the specific-spec inner cover 51 can be installed facing the stations X1 to X4 as a single component (inner cover) formed by integrating multiple components (inner covers). That is, at least one of the full-spec inner cover 50 and the specific-spec inner cover 51 can be configured as a single component (inner cover) formed by joining multiple components (inner covers) by screws, snaps, or the like. Even in such a case, the respective functions of the full-spec inner cover 50 and the specific-spec inner cover 51 described above can be exerted.

[0048] As described above, the image forming apparatus 1 of the present embodiment is provided with a plurality of stations X1-X4 to which the plurality of imaging units 10Y, 10M, 10C, and 10K can be attached or detached, respectively. The image forming apparatus 1 is also provided with a plurality of air inlets C1-C4 that allow air to be supplied to the plurality of stations X1-X4, and an air intake duct 41 that directs air taken in from outside the image forming apparatus main body 1 toward the plurality of air inlets C1-C4. The image forming apparatus 1 is also provided with a full-spec inner cover 50 that is installed on the image forming apparatus main body 1 when image formation is performed in a full-spec state in which the plurality of imaging units 10Y, 10M, 10C, and 10K are all installed in the plurality of stations X1-X4, allowing air to be supplied to all of the plurality of stations X1-X4 from all of the plurality of air inlets C1-C4 and allowing the plurality of imaging units 10Y, 10M, 10C, and 10K to be attached or detached to or from the plurality of stations X1-X4. The image forming apparatus further includes an inner cover 51 for specific specifications that is installed on the image forming apparatus main body 1 when image formation is performed in a specific specification state in which, among the multiple stations X1 to X4, there is a used station X4 where the imaging unit 10K is installed and unused stations X1 to X3 where the imaging units 10Y, 10M, and 10C are not installed, and that allows air to be supplied to the used station X4 from the air intake port C4 corresponding to the used station X4 among the multiple air intake ports C1 to C4, and prevents air from being supplied to the unused stations X1 to X3 through the other air intake ports C1 to C3, and that allows only the imaging unit 10K to be attached to and detached from the used station X4. This allows easy change from full spec state to specific spec state and from specific spec state to full spec state.

[0049] In this embodiment, the present invention is applied to an image forming apparatus 1 in which four-color (YMCK) imaging units 10Y, 10M, 10C, and 10K are installed in the full-spec state, and one imaging unit 10K is installed in the specific-spec state. However, the number of imaging units installed in the full-spec state and the number of imaging units installed in the specific-spec state are not limited to this. For example, in addition to the four full-color (YMCK) imaging units installed in the full-spec state, one imaging unit for clear color or infrared compatibility can also be added. Also, the number of color (YMC) imaging units installed in the specific-spec state can be three. Furthermore, in the present invention, the shape of air supply duct 41 and the positions of air supply ports C1 to C4 and air exhaust ports D1 to D4 are not limited to those in this embodiment. 4A and 4B, in this embodiment, when changing the specifications of the image forming apparatus 1, the full-spec inner cover 50 is replaced with the specific-spec inner cover 51. On the other hand, it is also possible to configure the inner cover facing the black imaging unit 10K (station X4), which is used in all specifications, as a common and always fixed cover, while the inner covers facing the color imaging units 10Y, 10M, and 10C (stations X1 to X3), which may or may not be used depending on the specifications, are replaced with ones corresponding to the respective specifications. In such cases, the same effect as that of this embodiment can be obtained.

[0050] It is to be noted that the present invention is not limited to the present embodiment, and it is clear that the present embodiment can be appropriately modified within the scope of the technical concept of the present invention in addition to the modifications suggested in the present embodiment. Furthermore, the number, position, shape, etc. of the components are not limited to the present embodiment, and the number, position, shape, etc. of the components can be any number, position, shape, etc. that is suitable for implementing the present invention. [Explanation of symbols]

[0051] 1 Image forming apparatus (image forming apparatus main body), 10Y, 10M, 10C, 10K imaging units (process cartridges), 11 photosensitive drum (image carrier), 12 charging device, 13 developing device, 41 Air supply duct, 45 Intake air fan, 50 inner cover (full spec inner cover), 50Y, 50M, 50C, 50K insertion port, 51 Inner cover (inner cover for specific specifications), 51K insertion port, 51a partition part (blocking means), 55 Intermediate transfer inner cover, 60 exterior cover (opening / closing cover), 70, 71 sealing member, A inlet, B outlet, C1~C4 air supply port, D1~D4 exhaust ports, X1~X4 stations (installation area).

[0052] The present invention can also be embodied in a combination of Supplementary Notes 1 to 9, as follows. (Appendix 1) a plurality of stations to which a plurality of imaging units can be attached and detached; a plurality of air inlets for respectively supplying air to the plurality of stations; an air intake duct for allowing air taken in from outside the image forming apparatus body to flow toward the plurality of air intake ports; a full-spec inner cover that is installed on the image forming apparatus body when image formation is performed in a full-spec state in which all of the plurality of imaging units are installed in the plurality of stations, and that enables air to be supplied to all of the plurality of stations from all of the plurality of air inlets and enables each of the plurality of imaging units to be attached to and detached from the plurality of stations; an inner cover for specific specifications that is installed on the image forming apparatus body when image formation is performed in a specific specification state in which there are used stations in which the imaging unit is installed and unused stations in which the imaging unit is not installed among the plurality of stations, and that allows air to be supplied to the used stations from the air supply ports corresponding to the used stations among the plurality of air supply ports, prevents air from being supplied to the unused stations through other air supply ports, and allows only the imaging unit to be attached to and detached from the used stations; An image forming apparatus comprising: (Appendix 2) an exterior cover that can open the inside of the image forming apparatus main body is installed on the front side that is operated by an operator; The image forming apparatus described in Appendix 1, characterized in that both the full-spec inner cover and the specific-spec inner cover are installed in the image forming apparatus main body with a gap on the inside side relative to the outer cover. (Appendix 3) The image forming apparatus described in Appendix 1 or Appendix 2, characterized in that the full-spec inner cover and the specific-spec inner cover are both installed as a single component or a single component integrating multiple components so as to face multiple stations. (Appendix 4) an intermediate transfer belt device disposed above the plurality of stations; an intermediate transfer inner cover disposed on the front side of the image forming apparatus body so as to be sandwiched between the intermediate transfer belt device and the outer cover; Equipped with An image forming apparatus as described in any one of Appendix 1 to Appendix 3, characterized in that both the full-spec inner cover and the specific-spec inner cover are abutted against the intermediate transfer inner cover so that no gaps are formed in the vertical direction. (Appendix 5) an intermediate transfer belt device disposed above the plurality of stations; an intermediate transfer inner cover disposed on the front side of the image forming apparatus body so as to be sandwiched between the intermediate transfer belt device and the outer cover; Equipped with An image forming apparatus as described in any one of Appendix 1 to Appendix 3, characterized in that both the full-spec inner cover and the specific-spec inner cover are installed so that a gap is formed in the vertical direction relative to the intermediate transfer inner cover. (Appendix 6) The image forming apparatus described in any one of Appendix 1 to Appendix 5, characterized in that the specific specification inner cover is configured to be able to exhaust air that has flowed into the air intake duct from outside the image forming apparatus main body but has not been supplied to the use station through the air intake port corresponding to the use station directly to the side away from the multiple stations. (Appendix 7) 7. The image forming apparatus according to claim 1, wherein the air flowing into the station from the air intake passes through the inside of the imaging unit installed in the station. (Appendix 8) 8. The image forming apparatus according to claim 1, wherein the air supply duct has an air supply fan provided upstream of the plurality of air supply ports in a direction of air flow. (Appendix 9) The plurality of image forming units include a black image forming unit and three color image forming units, The image forming apparatus according to any one of Supplementary Note 1 to Supplementary Note 8, wherein the specific specification state is a state in which monochrome image formation can be performed using only the black imaging unit. [Prior art documents] [Patent documents]

[0053] [Patent Document 1] Patent No. 6163877

Claims

1. a plurality of stations to which a plurality of imaging units can be attached and detached; a plurality of air inlets for respectively supplying air to the plurality of stations; an air intake duct for allowing air taken in from outside the image forming apparatus body to flow toward the plurality of air intake ports; a full-spec inner cover that is installed on the image forming apparatus body when image formation is performed in a full-spec state in which all of the plurality of imaging units are installed in the plurality of stations, and that enables air to be supplied to all of the plurality of stations from all of the plurality of air inlets and enables each of the plurality of imaging units to be attached to and detached from the plurality of stations; an inner cover for specific specifications that is installed on the image forming apparatus body when image formation is performed in a specific specification state in which there are used stations in which the imaging unit is installed and unused stations in which the imaging unit is not installed among the plurality of stations, and that allows air to be supplied to the used stations from the air supply ports corresponding to the used stations among the plurality of air supply ports, prevents air from being supplied to the unused stations through other air supply ports, and allows only the imaging unit to be attached to and detached from the used stations; An image forming apparatus comprising:

2. an exterior cover that can open the inside of the image forming apparatus main body is installed on the front side that is operated by an operator; 2. The image forming apparatus according to claim 1, wherein the full-spec inner cover and the specific-spec inner cover are both installed in the image forming apparatus body with a gap between them and the outer cover.

3. The image forming apparatus according to claim 1 or claim 2, characterized in that the full-spec inner cover and the specific-spec inner cover are both installed as a single component or a single component integrating multiple components so as to face multiple stations.

4. an intermediate transfer belt device disposed above the plurality of stations; an intermediate transfer inner cover disposed on the front side of the image forming apparatus body so as to be sandwiched between the intermediate transfer belt device and the outer cover; Equipped with 4. The image forming apparatus according to claim 3, wherein the full-spec inner cover and the specific-spec inner cover are both abutted against the intermediate transfer inner cover so that no gap is formed in the vertical direction.

5. an intermediate transfer belt device disposed above the plurality of stations; an intermediate transfer inner cover disposed on the front side of the image forming apparatus body so as to be sandwiched between the intermediate transfer belt device and the outer cover; Equipped with 4. The image forming apparatus according to claim 3, wherein the full-spec inner cover and the specific-spec inner cover are both installed such that a gap is formed between the full-spec inner cover and the intermediate transfer inner cover in the vertical direction.

6. The image forming apparatus of claim 1 or claim 2, characterized in that the specific specification inner cover is configured to exhaust air that flows into the air intake duct from outside the image forming apparatus main body but is not supplied to the use station through the air intake port corresponding to the use station directly to the side away from the multiple stations.

7. 3. The image forming apparatus according to claim 1, wherein the air flowing into the station through the air inlet passes through the interior of the imaging unit installed in the station.

8. 3. The image forming apparatus according to claim 1, wherein the air supply duct is provided with an air supply fan on the upstream side of the plurality of air supply ports in the air flow direction.

9. The plurality of image forming units include an image forming unit for black and three image forming units for color, 3. The image forming apparatus according to claim 1, wherein the specific specification state is a state in which monochrome image formation can be performed using only the black image forming unit.

Images