Image forming apparatus

Abstract

To easily and efficiently reduce an increase in the temperature of a plurality of stations when image formation is performed either in a full specification state or a limited specification state.SOLUTION: When image formation is performed in a full specification state in which a plurality of image forming units 10Y, 10M, 10C, 10K are all installed, air is supplied from all of a plurality of air inlets C1-C4 to all of a plurality of stations X1-X4. On the other hand, when image formation is performed in a limited specification state in which a use station X4 installed with the image forming unit 10K and non-use stations X1-X3 not installed with the image forming units 10Y, 10M, 10C are present, air is supplied from the air inlet C4 corresponding to the use station X4, and air is not supplied to and exhausted from the non-use stations X1-X3 through the air inlets C1-C3 other than the air inlet C4.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] With conventional techniques, it was difficult to simply and efficiently reduce temperature rises and the like in multiple stations, whether image formation was performed in a full-spec state in which multiple imaging units were all installed in multiple stations, or in a specific-spec state in which, among the multiple stations, there were used stations in which imaging units were installed and unused stations in which imaging units were not installed.

[0005] The present invention has been made to solve the above-mentioned problems, and aims to provide an image forming apparatus that can simply and efficiently reduce temperature rises and the like in multiple stations whether image formation is performed in full specification state or in specific specification 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 intake ports that enable air to be supplied to each of the plurality of stations, an air intake duct for directing air taken in from outside the image forming apparatus body toward the plurality of air intake ports, a plurality of air exhaust ports that enable air to be exhausted from each of the plurality of stations, and an exhaust duct for directing air exhausted from the plurality of air exhaust ports toward the outside of the image forming apparatus body.When image formation is performed in a full specification state in which all of the plurality of imaging units are installed in the plurality of stations, air is supplied to all of the plurality of stations from all of the plurality of air intake ports, and when image formation is performed in a specific specification 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, air is supplied to the used stations from the air intake ports of the plurality of air intake ports that correspond to the used stations, and air is not supplied to the unused stations through any other air intake ports, nor is air exhausted from the unused stations through any other air intake ports. [Effects of the Invention]

[0007] According to the present invention, an image forming apparatus can be provided that can easily and efficiently reduce temperature rises and the like in multiple stations, whether image formation is performed in a full specification state or in a specific 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 main body door open, and FIG. 1B is a perspective view showing an image forming apparatus in a specific specification state with the main body door 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 top view showing the air flow in an image forming apparatus in a specific specification state as a modified example. 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 indicates a paper feed device in which sheets P such as paper are stored, 10Y, 10M, 10C, and 10K indicate image-forming units corresponding to each color (yellow, magenta, cyan, and black), 17 indicates an intermediate transfer belt (image carrier) onto which toner images of multiple colors are transferred in layers, and 18 indicates 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 intended to cool the imaging units 10Y, 10M, 10C, and 10K, to collect toner scattered from the imaging units 10Y, 10M, 10C, and 10K (developing device 13), and to collect ozone generated in the imaging units 10Y, 10M, 10C, and 10K (charging device 12).

[0029] The image forming apparatus 1 (flow path) is provided with a plurality (four) of air intake ports C1 to C4, an air intake duct 41, an air intake fan 45, a plurality (four) of air exhaust ports D1 to D4, an exhaust duct 42, an exhaust fan 46, a filter 47, etc.

[0030] 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.

[0031] Referring to FIG. 4A, in this embodiment, an opening / closing cover 60 that exposes the interior of the image forming apparatus 1 is provided on the front side (the side where the user mainly performs operations) of the image forming apparatus main body 1. When the opening / closing cover 60 is opened (as shown in FIG. 4A), the inner cover 50 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.

[0032] Referring to FIG. 3(A), a plurality of exhaust ports D1 to D4 enable exhaust from a plurality of stations X1 to X4, respectively. The exhaust duct 42 is for causing the air exhausted from the plurality of exhaust ports D1 to D4 to flow through the outlet B toward the outside of the image forming apparatus main body 1. Specifically, in this embodiment, four exhaust ports D1 to D4 are formed in the exhaust duct 42 at positions facing the rear sides (upper side in Figure 3(A), and toward the back in the direction perpendicular to the paper surface in Figure 1) of the four imaging units 10Y, 10M, 10C, and 10K. Furthermore, exhaust duct 42 is provided with an exhaust fan 46 and a filter 47 downstream of the plurality of exhaust ports D1 to D4 in the air flow direction (on the left side in FIG. 3A). When exhaust fan 46 is driven, the air inside exhaust duct 41 is actively expelled from outlet B. Furthermore, filter 47 captures toner (dust) and ozone and allows only clean air to pass through, thereby reducing the problem of scattered toner and ozone generated in imaging units 10Y, 10M, 10C, and 10K floating inside image forming apparatus 1 or being released to the outside. The upstream-downstream positional relationship between the exhaust fan 46 and the filter 47 in the exhaust duct 42 is not limited to that shown in Fig. 3(A). The filter 47 may also be provided as an ozone filter and a dust filter (toner filter) separately.

[0033] 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 space W surrounded by dashed lines in FIG. 2) and is exhausted from exhaust ports D1 to D4 of stations X1 to X4. That is, air escapes from the front side to the rear side within imaging units 10Y, 10M, 10C, and 10K. This configuration improves the cooling performance of the imaging units 10Y, 10M, 10C, and 10K, and also makes it easier to carry the toner scattered from the developing device 13 and the ozone generated by the charging device 12 into the airflow, thereby improving the ability to capture them.

[0034] 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 incurring significant costs.

[0035] 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 suppression performance) of the imaging units 10Y, 10M, 10C, and 10K, as well as the collection performance of toner scattered from the developing device 13 and the collection performance of ozone generated by the charging device 12.

[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) via the other air intakes C1 to C3, nor is air exhausted from the unused stations X1 to X3 (color imaging units 10Y, 10M, 10C) via the other air intakes C1 to C3 (air intakes C1 to C3 do not function as exhaust ports). Furthermore, when image formation is performed in a "specific specification state" (when used as a monochrome image forming apparatus 1), exhaust is performed to the exhaust duct 42 through the exhaust port D4 corresponding to the used station ≡4, and exhaust is performed to the exhaust duct 42 through at least one of the multiple exhaust ports D1 to D3 corresponding to the multiple unused stations X1 to X3 (in this embodiment, all three exhaust ports D1 to D3).

[0037] Specifically, in this embodiment, when in a "specific specification state" (when used as a monochrome image forming apparatus 1), a blocking unit 51a is detachably installed as a blocking means that connects only the air intake C4 corresponding to the used station X4 to the used station X4 (black imaging unit 10K), and does not connect the other air intakes C1 to C4 to the unused stations X1 to X3. This blocking portion 51a (blocking means) is formed as a part of the inner cover 51 for the specific specification state (inner cover for the specific specification) that is installed in place of the inner cover 50 for the full specification state (inner cover for the full specification) in the specific specification state. That is, in the "specific specification state" (when used as the monochrome image forming apparatus 1), the specific specification inner cover 51 is detachably installed so that only the air intake port C4 corresponding to the used station X4 communicates with the used station X4 (black imaging unit 10K) and the other air intake ports C1 to C4 do not communicate with the unused stations X1 to X3. In addition, the blocking portion 51a (blocking 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 side contacts the intermediate transfer inner cover 55 (see Figure 4) 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). Since the blocking portion 51a (specific specification inner cover 51) is installed on the front side of the image forming apparatus 1, the installation work (attachment and detachment work) is extremely simple.

[0038] Here, in this embodiment, the blocking section 51a (blocking means) is configured to be able to exhaust, from the air that has flowed into the air supply duct 41 from outside the image forming apparatus main body 1, the air that has not been supplied to the use station X4 (black imaging unit 10K) from the air supply port C4 corresponding to the use station X4 (black imaging unit 10K), 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 overall air flow is formed as shown by the black arrows in Fig. 3(B), which, as explained above, improves the cooling performance (temperature rise prevention performance) of the black imaging unit 10K, as well as the collection performance of toner scattered from the developing device 13 of the black imaging unit 10K and the collection performance of ozone generated by the charging device 12 of the black imaging unit 10K.

[0039] As shown in FIG. 4(B) (and FIG. 3(B)), in the specific specification state, insertion openings for attaching and detaching the color imaging units 10Y, 10M, and 10C are not necessary. Therefore, instead of the inner cover 50 for the full specification state (full specification inner cover), an inner cover 51 (specific specification inner cover with a blocking portion 51a) formed with only an insertion opening 51K for attaching and detaching the black imaging unit 10K is installed. As described above, the air intake duct 41 is installed inside the exterior cover 60. 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 of the specific specification inner cover 51. The air intake duct 41 is commonly used in both the full specification state and the specific specification state. By installing the 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 the specific specifications are met.

[0040] In this manner, in this embodiment, whether image formation is performed in the full specification state or in the specific specification state, temperature rise in the plurality of stations X1 to X4, toner scattering from the plurality of stations X1 to X4 to the outside of the image forming apparatus, and ozone release can be easily and efficiently reduced by simply attaching and detaching one blocking portion 51a (specific specification inner cover 51).

[0041] More specifically, as shown in Figure 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. This allows for almost uniform cooling of all imaging units 10Y, 10M, 10C, and 10K, and also allows for almost uniform collection of toner scattered from all developing devices 13 and collection of ozone generated by all charging devices 12.

[0042] As shown in Figure 3(B), in a specific specification state, a flow path is formed that allows air to pass from the front side to the rear side only for the black imaging unit 10K (used station X4), and no such flow path is formed for the other color imaging units 10Y, 10M, and 10C (unused stations X1 to X3).Therefore, compared to a case in which such a flow path is also formed for the unusable stations X1 to X3, as in the image forming apparatus 100 shown in Figure 5(A) as a comparative example, the cooling performance for the black imaging unit 10K (used station X4) can be improved, and the ability to collect toner scattered from the developing device 13 of the black imaging unit 10K and the ability to collect ozone generated by the charging device 12 of the black imaging unit 10K can be improved. In particular, if such a flow path is formed also for the unused stations X1 to X3, as in the image forming apparatus 100 shown in Fig. 5(A) as a comparative example, toner scattered from the developing device 13 of the black imaging unit 10K flows as shown by the arrow S in Fig. 2 and spreads into the unused stations X1 to X3, which are large spaces, causing the unused stations X1 to X3 to become contaminated with the scattered toner. In contrast, in the present embodiment, air is not supplied to the unused stations X1 to X3 under specific specification conditions, thereby reducing the occurrence of such problems.

[0043] On the other hand, as shown in Figure 3(B), in the specific specification state, as in the full specification state, not only the exhaust port D4 corresponding to the black imaging unit 10K (used station X4), but all four exhaust ports D1 to D4 are left open. 5B, as a comparative example, in which only the exhaust port D4 corresponding to the black imaging unit 10K (used station X4) is open and the exhaust ports D1 to D3 of the unused stations X1 to X3 are sealed with the sealing member 70 (the three air inlets C1 to C3 are also sealed with the sealing member 71), this configuration makes it less likely that scattered toner generated in the developing device 13 of the black imaging unit 10K (used station X4) will flow to and accumulate at the unused stations X1 to X3. That is, in this embodiment, scattered toner dispersed from the used station X4 to the unused stations X1 to X3 is discharged into the exhaust duct 42 via the exhaust ports D1 to D3 and ultimately collected by the filter 47. In order to obtain this effect, it is not necessary for all three exhaust ports D1 to D3 corresponding to unused stations X1 to X3 to be open; it is sufficient if at least one of the three exhaust ports D1 to D3 is open.

[0044] 3(B) and other figures, in image forming apparatus 1 in a specific specification state, air intake duct 41 and inner cover 51 (inner cover for specific specifications) 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 (particularly the YMC portion), 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 black imaging unit 10K without adjusting or replacing air intake fan 45. Furthermore, the image forming apparatus 1 in the specific specification state in this embodiment is simply a full specification state to which a blocking section 51a (inner cover 51 for specific specifications) is installed, so there is no need for the time-consuming work of installing sealing members 70 to seal the three exhaust ports D1 to D3, or installing sealing members 71 to seal the three intake ports C1 to C3, as in the image forming apparatus 200 shown in Figure 5(B) as a comparative example.

[0045] <Modification> As shown in FIG. 6, the image forming apparatus 1 in the modified example has a detachable partition member 59 as a blocking means that separates the flow path of the air supply duct 41 when printing under specific specifications (when used as a monochrome image forming apparatus 1). In detail, the partition member 59 (blocking means) is installed in the air intake duct 41 downstream of the air intake port C4 corresponding to the black imaging unit 10K (used station X4) and upstream of the air intake ports C1 to C3 corresponding to the color imaging units 10Y, 10M, 10C (unused stations X1 to X3) so as to block the flow path. Even in this configuration, air is supplied only from the air supply port C4 corresponding to the black imaging unit 10K (used station X4). Therefore, even in the modified example, whether image formation is performed in a full specification state or in a specific specification state, temperature rises and the like in the multiple stations X1 to X4 can be easily and efficiently reduced. In addition, when a partition member 59 (blocking means) is provided in the air intake duct 41 in this specific specification state, a specific specification inner cover 51 (see Figure 6) that does not have a blocking portion 51a formed therein is installed in place of the full specification inner cover 50.

[0046] As described above, image forming apparatus 1 in this embodiment is provided with multiple stations X1-X4 to which multiple imaging units 10Y, 10M, 10C, and 10K can be attached or detached. Also provided are multiple air inlets C1-C4 that allow air to be supplied to each of stations X1-X4, an air intake duct 41 that directs air taken in from outside image forming apparatus main body 1 toward the multiple air inlets C1-C4, multiple air exhaust ports D1-D4 that allow air to be exhausted from each of stations X1-X4, and an exhaust duct 42 that directs air exhausted from the multiple air exhaust ports D1-D4 toward the outside of image forming apparatus main body 1. When image formation is performed in a full-spec state in which multiple imaging units 10Y, 10M, 10C, and 10K are all installed in stations X1-X4, air is supplied to all of stations X1-X4 from all of the multiple air inlets C1-C4. In contrast, when image formation is performed under a specific specification condition in which, among the multiple stations X1 to X4, there is a used station X4 equipped with imaging unit 10K and unused stations X1 to X3 not equipped with imaging units 10Y, 10M, and 10C, air is 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 air is not supplied to the unused stations X1 to X3 via the other air intake ports C1 to C4, nor is air exhausted from the unused stations X1 to X3 via the other air intake ports C1 to C3. This makes it possible to easily and efficiently reduce temperature rises and the like in the plurality of stations X1 to X4 whether image formation is performed in a full specification state or in a specific specification state.

[0047] 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 shapes of air supply duct 41 and air exhaust duct 42 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. Furthermore, the imaging units 10Y, 10M, 10C, and 10K installed in stations X1 to X4 are not limited to those of this embodiment, and as long as they are provided with at least a photosensitive drum 11 (image carrier), a charging device 12 that charges the photosensitive drum 11, and a developing device 13 that develops the latent image formed on the surface of the photosensitive drum 11, it is possible to obtain the effect of improving the ability to collect toner scattered from the developing device 13 and the ability to capture ozone generated by the charging device 12. In such cases, the same effect as that of this embodiment can be obtained.

[0048] 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. In contrast to this, at least one of the full-spec inner cover 50 and the specific-spec inner cover 51 can be installed as a single component (inner cover) in which multiple components (inner covers) are integrated, facing multiple stations X1 to X4. 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) in which multiple components (inner covers) are joined together by screws, snaps, or the like. In such a case, the same effect as that of this embodiment can be obtained.

[0049] 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]

[0050] 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, 42 exhaust duct, 45 Intake air fan, 46 exhaust fan, 47 filters, 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 interrupting unit (interrupting means), 55 Intermediate transfer inner cover, 59 Partition member (blocking means), 70, 71 sealing member, A inlet, B outlet, C1~C4 air supply port, D1~D4 exhaust ports, X1~X4 stations (installation area).

[0051] The present invention can also be embodied in a combination of Supplementary Notes 1 to 8, 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 plurality of exhaust ports for allowing exhaust from each of the plurality of stations; an exhaust duct for allowing the air exhausted from the plurality of exhaust ports to flow toward the outside of the image forming apparatus body; Equipped with When image formation is performed in a full-spec state in which all of the imaging units are installed in the plurality of stations, air is supplied to all of the plurality of stations from all of the plurality of air supply ports, When image formation is performed under a specific specification state in which, among the plurality of stations, there are used stations in which the imaging unit is installed and unused stations in which the imaging unit is not installed, air is supplied to the used stations from the air intake ports among the plurality of air intake ports corresponding to the used stations, and air is not supplied to the unused stations through other air intake ports, nor is air exhausted from the unused stations through other air intake ports. (Appendix 2) When image formation is performed in the full specification state, air is exhausted from all of the plurality of stations to the exhaust duct through the plurality of exhaust ports, The image forming apparatus described in Appendix 1 is characterized in that when image formation is performed in the specific specification state, exhaust is performed to the exhaust duct through an exhaust port corresponding to the used station, and exhaust is performed to the exhaust duct through at least one exhaust port out of a plurality of exhaust ports corresponding to a plurality of the unused stations. (Appendix 3) The image forming apparatus according to claim 1 or 2, characterized in that when in the specific specification state, a blocking means is detachably installed that connects only the air intake corresponding to the used station to the used station and does not connect the other air intakes to the unused station. (Appendix 4) The image forming apparatus described in Appendix 3 is characterized in that the blocking means is configured to exhaust air that has flowed into the air supply duct from outside the image forming apparatus main body but has not been supplied to the use station through the air supply port corresponding to the use station directly to the side away from the multiple stations. (Appendix 5) An image forming apparatus as described in any one of Appendix 1 to Appendix 4, characterized in that air flowing into the station from the air intake port passes through the inside of the imaging unit installed in the station and is exhausted from the exhaust port of the station. (Appendix 6) the air supply duct is provided with an air supply fan upstream of the plurality of air supply ports in an air flow direction, The image forming apparatus according to any one of claims 1 to 5, wherein the exhaust duct is provided with an exhaust fan and a filter downstream of the plurality of exhaust ports in the air flow direction. (Appendix 7) The image forming apparatus according to any one of Appendix 1 to Appendix 6, characterized in that the imaging unit is provided with at least an image carrier, a charging device that charges the image carrier, and a developing device that develops a latent image formed on the surface of the image carrier. (Appendix 8) 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 7, 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]

[0052] [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 plurality of exhaust ports for allowing exhaust from each of the plurality of stations; an exhaust duct for allowing the air exhausted from the plurality of exhaust ports to flow toward the outside of the image forming apparatus body; Equipped with When image formation is performed in a full-spec state in which all of the imaging units are installed in the plurality of stations, air is supplied to all of the plurality of stations from all of the plurality of air supply ports, When image formation is performed under a specific specification state in which, among the plurality of stations, there are used stations in which the imaging unit is installed and unused stations in which the imaging unit is not installed, air is supplied to the used stations from the air intake ports among the plurality of air intake ports corresponding to the used stations, and air is not supplied to the unused stations through other air intake ports, nor is air exhausted from the unused stations through other air intake ports.

2. When image formation is performed in the full specification state, air is exhausted from all of the plurality of stations to the exhaust duct through the plurality of exhaust ports, 2. The image forming apparatus according to claim 1, wherein when image formation is performed in the specific specification state, exhaust is performed to the exhaust duct through an exhaust port corresponding to the in-use station, and exhaust is performed to the exhaust duct through at least one exhaust port among a plurality of exhaust ports corresponding to a plurality of the non-use stations.

3. 3. The image forming apparatus according to claim 1, further comprising a detachable blocking means for connecting only the air intake port corresponding to the used station to the used station when the specific specification state is in effect, and preventing other air intake ports from connecting to the unused station.

4. The image forming apparatus according to claim 3, characterized in that the blocking means is configured to exhaust air that has flowed into the air supply duct from outside the image forming apparatus main body but has not been supplied to the use station through the air supply port corresponding to the use station directly to a side away from the plurality of stations.

5. 3. An image forming apparatus according to claim 1, wherein air flowing into the station through the air intake port passes through the inside of the imaging unit installed in the station and is exhausted from the exhaust port of the station.

6. the air supply duct is provided with an air supply fan upstream of the plurality of air supply ports in an air flow direction, 3. The image forming apparatus according to claim 1, wherein the exhaust duct is provided with an exhaust fan and a filter downstream of the plurality of exhaust ports in the air flow direction.

7. 3. The image forming apparatus according to claim 1, wherein the imaging unit includes at least an image carrier, a charging device for charging the image carrier, and a developing device for developing a latent image formed on the surface of the image carrier.

8. 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