Image forming apparatus

Abstract

To form ducts inside resin inside covers, and to dispose the inside covers having the ducts formed therein in a housing while preventing the generation of warpage of the inside covers.SOLUTION: An inside cover unit 125 is divided into a first inside cover 201 and a second inside cover 202, which are made of resin. The first inside cover 201 and the second inside cover 202 have a plurality of ducts formed therein. A user can attach the inside cover unit 125 obtained by integrating the first inside cover 201 and the second inside cover 202 to a housing. Dividing the inside cover unit 125 into the first inside cover 201 and the second inside cover 202 can reduce the dimensions in a longitudinal direction of both components, the first inside cover 201 and the second inside cover 202. Consequently, attaching the first inside cover 201 and the second inside cover 202 having the reduced longitudinal dimensions and thus hardly generating warpage allows disposition of the inside cover unit 125 hardly generating warpage on the housing.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to an image forming apparatus such as a printer, a copier, a facsimile machine, or a multifunction machine.

Background Art

[0002] Conventionally, an image forming apparatus has been proposed that includes an exterior cover provided on a housing so as to be openable and closable, and a separate inner cover disposed inside the exterior cover in a closed state (Patent Document 1). Inside the inner cover, an image forming unit having a photosensitive drum, a charger, a developing device, etc. is disposed. The inner cover is provided so that, for example, when a so-called jam occurs where the recording material is clogged in the middle of the conveyance path without being discharged, and the user opens the exterior cover to remove the clogged recording material, the user does not accidentally touch the power supply unit or movable parts of the image forming unit.

[0003] In addition, the image forming apparatus may be provided with a fan that sucks air from the outside, and a number of ducts that guide the air sucked from the outside by the fan toward an image forming section having, for example, a charger and a developing device. Passing air toward the image forming section is for collecting discharge products such as ozone generated during charging of the charger, and for suppressing the temperature rise of the developing device accompanying the toner agitation operation in the developing device.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Incidentally, recently, image forming machines for commercial printing that can form toner images on a large amount of recording material in a short time are being used. In such machines, the amount of discharge products generated from the charger tends to be large and the developer tends to heat up easily, so a large fan capable of drawing in and supplying a large amount of air is used. However, there is a demand for miniaturization in image forming machines for commercial printing, and there is not enough space to install a large fan near the charger and developer inside the housing, so the large fan is placed at a distance from the charger and developer, and the duct is made longer accordingly. To reduce the pressure loss in the duct due to the length of the duct, it is necessary to form a duct with a large flow path cross-sectional area. Therefore, it is conceivable to form the duct in the inner cover made of resin, where there is relatively ample space. The inner cover is manufactured using a processing machine that uses resin injection molding.

[0006] However, in image forming machines for commercial printing, multiple image forming units for forming toner images on recording material are arranged in parallel, and the inner cover becomes longer in the longitudinal direction (the direction in which the image forming units are arranged). As a result, the inner cover is prone to warping in proportion to its size. If the inner cover is warped, it becomes difficult to attach it to the housing, and even if the inner cover is attached to the housing, there is a risk that the duct will not be positioned correctly.

[0007] The present invention has been made in view of the above problems, and aims to provide an image forming apparatus that can form a duct in a resin inner cover while suppressing warping of the inner cover, and can install the inner cover with the duct formed thereon into a housing. [Means for solving the problem]

[0008] An image forming apparatus according to one embodiment of the present invention comprises a housing, an image forming unit provided in the housing and forming a toner image on a recording material, an outer cover provided in the housing so as to be openable and closable, a first inner cover made of resin disposed opposite to the inner surface of the outer cover when closed, and a second inner cover made of resin disposed opposite to the inner surface of the outer cover when closed and adjacent to the first inner cover, wherein the first inner cover has a first duct on the first cover surface on the side of the image forming unit opposite to the outer cover for guiding air drawn in from the outside to the image forming unit, and the second inner cover has a second duct on the second cover surface on the side of the image forming unit opposite to the outer cover for guiding air drawn in from the outside to the image forming unit. [Effects of the Invention]

[0009] According to the present invention, when a duct is formed in a resin inner cover, warping of the inner cover can be suppressed, and the inner cover with the duct can be installed in the housing. [Brief explanation of the drawing]

[0010] [Figure 1] A schematic diagram showing an image forming system equipped with the image forming apparatus of this embodiment. [Figure 2] (a) Left perspective view, (b) Right perspective view, showing the front door of the image forming apparatus in the closed position. [Figure 3] A perspective view showing the left-side air blower unit. [Figure 4] A perspective view showing the right-side air blower unit. [Figure 5] A schematic diagram illustrating the airflow to the charger. [Figure 6] A perspective view showing the front door of the image forming apparatus in the open position. [Figure 7] (a) A schematic diagram showing the inner surface of the inner cover unit of the first embodiment, (b) A vertical cross-sectional view showing the configuration of the duct, and (c) A horizontal cross-sectional view showing the connection part of the duct. [Figure 8](a) Top view showing the release state by the fixing part, (b) Front view showing the release state by the fixing part, (c) Top view showing the fixed state by the fixing part, (d) Front view showing the fixed state by the fixing part. [Figure 9] (a) A schematic diagram showing the inner surface of the inner cover unit of the second embodiment, (b) A schematic diagram showing the connection part of the duct, and (c) A schematic diagram showing the intermediate duct. [Figure 10] (a) A schematic diagram showing the inner surface of an inner cover unit in which the first inner cover and the second inner cover can be opened and closed; (b) A schematic diagram showing the opening and closing operation of the first inner cover and the second inner cover; (c) A schematic diagram showing the relay duct. [Modes for carrying out the invention]

[0011] [First Embodiment] <Image Forming System> The schematic configuration of the image forming system equipped with the image forming apparatus of this embodiment will be explained with reference to Figure 1. The image forming system 1X shown in Figure 1 includes an image forming apparatus 100 and a finisher apparatus 300. The image forming apparatus 100 and the finisher apparatus 300 are connected so as to be able to receive recording material S. In this embodiment, the finisher apparatus 300 is a post-processing unit that can be retrofitted to the image forming apparatus 100 for functional expansion, and can perform post-processing described later on the recording material S on which the toner image has been fixed by the image forming apparatus 100. The image forming apparatus 100 and the finisher apparatus 300 are connected so as to be able to send and receive data between them via a communication interface capable of serial communication and parallel communication.

[0012] <Image forming apparatus> The image forming apparatus 100 is an electrophotographic tandem full-color printer and has a first housing 101a and a second housing 101b. The first housing 101a is equipped with various devices and components that realize the process from transporting the recording material S to transferring the toner image. On the other hand, the second housing 101b is equipped with various devices and components, such as a fixing unit 800 that realizes the process of transporting the recording material S and fixing the toner image. The second housing 101b is also equipped with an operation unit 200 on the front side that has a display unit capable of displaying various information and keys that allow various information to be input according to user operation. The second housing 101b is located on one end side of the first housing 101a in the left-right direction of the image forming apparatus 100 (the direction in which the image forming units Pa to Pd are arranged, the longitudinal direction), and the first housing 101a and the second housing 101b are connected so that the recording material S can be passed between them.

[0013] In this specification, the side from which the user stands when operating the control unit 200 is referred to as the "front (or front)," and the opposite side is referred to as the "back (or rear)." Also, the left side when viewed from the front is referred to as the "left," and the right side when viewed from the front is referred to as the "right." Therefore, Figure 1 shows the image forming system 1X as viewed from the front.

[0014] The image forming apparatus 100 is equipped with four image forming units Pa, Pb, Pc, and Pd, which each form yellow, magenta, cyan, and black images, respectively. The image forming apparatus 100 forms a toner image on the recording material S in accordance with an image signal received from an original document reader 190 that reads an image signal from an original document or from an external device (not shown) such as a personal computer. The recording material S can be any type of paper such as plain paper, cardboard, rough paper, textured paper, or coated paper, or it can be plastic film or cloth.

[0015] As shown in FIG. 1, image forming units Pa to Pd as image forming units are arranged side by side along an intermediate transfer belt 130. The intermediate transfer belt 130 is stretched over a plurality of rollers (13, 14, 15) and is moved in the direction of arrow R2. Then, the intermediate transfer belt 130 carries and conveys a toner image that is primarily transferred as described later. A secondary transfer outer roller 11 is arranged at a position facing the secondary transfer inner roller 14 that stretches the intermediate transfer belt 130 with the intermediate transfer belt 130 interposed therebetween, forming a secondary transfer unit T2 that transfers the toner image on the intermediate transfer belt 130 to a recording material S. A fixing unit 800 is arranged downstream of the secondary transfer unit T2 in the recording material conveyance direction (arrow X direction).

[0016] On the lower side of the image forming apparatus 100, a plurality (here, two) of cassettes 10 in which the recording material S is housed are arranged. These cassettes 10 house recording materials S having different sizes and thicknesses, and the recording material S is selectively conveyed from any of the cassettes 10. The recording material S is conveyed from the cassette 10 through a conveyance path by a conveyance roller 16 toward a registration roller 12. Thereafter, the registration roller 12 rotates in synchronization with the toner image formed on the intermediate transfer belt 130, whereby the recording material S is conveyed toward the secondary transfer unit T2. Note that, not limited to the recording material S housed in the cassette 10, the recording material S placed on a manual feeding unit (not shown) may be conveyed.

[0017] The image forming units Pa, Pb, Pc, Pd have substantially the same configuration except that the developing colors of the toner images are different. Therefore, here, the yellow image forming unit Pa will be described as a representative, and the description of the other image forming units Pb, Pc, Pd will be omitted.

[0018] A photosensitive drum 3a as a photoreceptor is disposed in the image forming unit Pa. The photosensitive drum 3a is rotationally driven by a motor (not shown). Around the photosensitive drum 3a, a charger 2a, an exposure device La, a developing device 1a, a primary transfer roller 24a, and a drum cleaning device 4a are arranged.

[0019] The process of forming, for example, a full-color image using the image forming apparatus 100 will now be described. First, when the image forming operation is started, the surface of the rotating photosensitive drum 3a is uniformly charged by the charger 2a. The charger 2a is, for example, a corona charger that charges the surface of the photosensitive drum 3a to a uniform potential by irradiating it with charged particles associated with corona discharge. Next, the photosensitive drum 3a is scanned and exposed by laser light corresponding to the image signal emitted from the exposure unit La. As a result, an electrostatic latent image corresponding to the image signal is formed on the surface of the photosensitive drum 3a. The electrostatic latent image formed on the photosensitive drum 3a is developed into a toner image, which is a visible image, by a developer containing toner and carriers contained in the developer unit 1a. In other words, the photosensitive drum 3a is developed into a toner image by the supply of toner from the developer unit 1a. In the developers 1a to 1d, the developer is circulated and transported while being agitated by a transport screw (not shown).

[0020] The toner image formed on the photosensitive drum 3a is transferred to the intermediate transfer belt 130 in a primary transfer section, which consists of the drum 3a and the primary transfer roller 24a positioned on either side of the intermediate transfer belt 130. At this time, a primary transfer voltage is applied to the primary transfer roller 24a. After the primary transfer, any toner remaining on the surface of the photosensitive drum 3a is removed by the drum cleaning device 4a.

[0021] This process is performed sequentially in the yellow, magenta, cyan, and black image forming units Pa to Pd, superimposing the four toner images on the intermediate transfer belt 130. Subsequently, the recording material S contained in the cassette 10 is transported to the secondary transfer unit T2 in accordance with the toner image formation timing. Then, by applying a secondary transfer voltage to the secondary transfer outer roller 11, the full-color toner image formed on the intermediate transfer belt 130 is transferred to the recording material S all at once. Any toner remaining on the intermediate transfer belt 130 after the secondary transfer is removed by a belt cleaning device (not shown).

[0022] The recording material S onto which the toner image has been transferred is transported to the fuser unit 800. The fuser unit 800 fixes the toner image to the recording material S by applying heat and pressure to the recording material S onto which the toner image has been transferred. In this embodiment, it is possible to selectively apply heat and pressure to the recording material S by the first fuser 81 and then further apply heat and pressure by the second fuser 91. The fuser unit 800 can switch, using the fuser switching flapper 95, whether to transport the recording material S towards the second fuser 91 after passing through the first fuser 81, or to transport it while avoiding the second fuser 91 after passing through the first fuser 81.

[0023] The second fuser 91 is located downstream of the first fuser 81 in the transport direction of the recording material S. The second fuser 91 is used selectively for purposes such as adding gloss to the toner image on the recording material S fixed by the first fuser 81. For example, if the recording material S is coated paper such as glossy paper or synthetic paper, the recording material S that has passed through the first fuser 81 is transported along the fixing route 30a so that fixing occurs in both the first fuser 81 and the second fuser 91. On the other hand, if the recording material S is uncoated paper such as plain paper, the recording material S that has passed through the first fuser 81 is transported along the fixing bypass route 30b, which avoids the second fuser 91, so that fixing occurs in the first fuser 81 but not in the second fuser 91.

[0024] The first fuser 81 and the second fuser 91 described above may have the same configuration, so here we will explain using the first fuser 81 as an example. The first fuser 81 has a fuser roller 82 (or fuser belt) that is rotatable and in contact with the surface of the recording material S on which the toner image is fixed, and a pressure belt 83 (or pressure roller) that presses against the fuser roller 82 to form a fuser nip. At least one of the fuser roller 82 and the pressure belt 83 is heated by a heater (not shown). In the fuser nip formed by the fuser roller 82 and the pressure belt 83, the first fuser 81 applies heat and pressure to the recording material S on which the toner image is formed when it grips and transports the recording material S, thereby fixing the toner image to the recording material S.

[0025] In this embodiment, the image forming apparatus 100 is capable of double-sided printing. In the case of single-sided printing, the recording material S on which the toner image has been fixed is transported to the discharge transport path 150 and discharged to the outside of the image forming apparatus 100. In the case of double-sided printing, the recording material S on which the toner image has been fixed is transported to the double-sided inversion transport path 600. The double-sided inversion transport path 600 is formed across the first housing 101a and the second housing 101b. In the double-sided inversion transport path 600, the recording material S is inverted by a switchback operation, and the front and back sides of the recording material S are swapped. The inverted recording material S is transported toward the registration roller 12, and the registration roller 12 transports it to the secondary transfer section T2 with the unprinted back side facing the intermediate transfer belt 130. In the secondary transfer section T2, the full-color toner image formed on the intermediate transfer belt 130 is transferred all at once to the recording material S (back side). Subsequently, the recording material S is fixed with a toner image by the fixing unit 800 and discharged to the outside of the image forming apparatus 100 with the surface that was image-formed immediately before (image-forming surface) facing upwards. The switching between the discharge transport path 150 and the double-sided inversion transport path 600 is performed by the transport switching flapper 160.

[0026] A finisher device 300 is connected to the image forming apparatus 100 so as to be able to receive recording material S, and the recording material S discharged from the image forming apparatus 100 is transported to the finisher device 300. The recording material S transported to the finisher device 300 undergoes post-processing such as punching holes in the recording material S or stapling multiple sheets of recording material S together. In the finisher device 300, the punched recording material S is discharged to the upper discharge tray 301, and the bundles of stapled recording material S are discharged to the lower discharge tray 302.

[0027] Next, the airflow configuration in the first housing 101a will be explained using Figures 2(a) to 6 with reference to Figure 1. As shown in Figure 2(a), the front of the first housing 101a has a left front door 170a and a right front door 170b, which serve as outer covers and can be opened and closed like double doors, with the left and right sides approximately in the center. An intake cover 171 is provided above the left front door 170a, and an intake port 171a is formed on the intake cover 171 facing forward. Also, as shown in Figure 2(b), a right cover 172 is provided on the right side of the first housing 101a, and an intake port 172a is formed on the right cover 172.

[0028] <Air blower unit> As shown in Figure 3, a left-side ventilation unit 124 is provided on the left side of the first housing 101a, which has a fan that draws in air from the intake port 171a and blows it out. The left-side ventilation unit 124 has a left-side main duct 174, ventilation fans 180a and 180b, and a side duct 1741. The air drawn in from the intake port 171a is blown towards the developing units 1a to 1d and the chargers 2a and 2b, which are supported by the first housing 101a, via the left-side ventilation unit 124 and the inner cover unit 125, which will be described later. The left-side main duct 174 is a duct with a space formed inside that communicates with the intake port 171a.

[0029] The blower fans 180a and 180b and the side duct 1741 are located on the left side of the left main duct 174. Specifically, the left main duct 174 has a communication port that connects to the blower fans 180a and 180b, and the air drawn in from the intake port 171a in accordance with the operation of the blower fans 180a and 180b passes through the inside of the left main duct 174. The air drawn in from the intake port 171a passes through a filter (not shown) to remove dust and other particles from the air. The side duct 1741 has ducts 181a, 181b, and 181c formed inside. The side duct 1741 and the blower fans 180a and 180b are connected so that the air that has passed through the blower fans 180a and 180b passes through the ducts 181a and 181b (see dashed arrows).

[0030] Although not shown in the diagram here, four blower fans (not shown) are provided on the right side of the left main body duct 174, opposite to the side where the side duct 1741 is located. Each of these four blower fans is capable of drawing in air from outside the image forming apparatus 100 via an air intake 171a. The air drawn in by the four blower fans on the right side of the left main body duct 174 is sent to the destination, for example, via duct 181c. Although other components besides ducts 181a to 181c are not shown in the diagram here, the left ventilation unit 124 has ventilation ducts formed for each destination developer unit 1a to 1d and charger unit 2a and 2b.

[0031] As shown in Figure 4, a right-side ventilation unit 126, which has a fan that draws in air from the intake port 172a and blows it out, is installed on the right side of the first housing 101a. The right-side ventilation unit 126 has a right-side main duct 176, ventilation fans 180c and 180d, and a through duct 179. The air drawn in from the intake port 172a is blown towards the chargers 2c and 2d supported by the first housing 101a via the right-side ventilation unit 126 and the inner cover unit 125, which will be described later. The right-side main duct 176 is a duct with a space formed inside that communicates with the intake port 172a formed on the right side of the image forming apparatus 100.

[0032] The blower fans 180c and 180d and the through duct 179 are located on the right side of the right main duct 176. Specifically, the right main duct 176 has a communication port that connects to the blower fans 180c and 180d, and the air drawn in from the intake port 172a in accordance with the operation of the blower fans 180c and 180d passes through the inside of the right main duct 176. The air drawn in from the intake port 172a passes through a filter (not shown) to remove dust and other particles from the air. The through duct 179 has ducts 181c and 181d formed inside. The through duct 179 and the blower fans 180c and 180d are connected so that the air that has passed through the blower fans 180c and 180d passes through the ducts 181c and 181d (see dashed arrows). The blower fans 180a to 180d are, for example, sirocco fans.

[0033] As shown in Figures 3 and 4, the fans for blowing air (180a to 180d) are located on the right and left sides of the first housing 101a. Furthermore, the blowing fans 180a to 180d are positioned far from the front where the user operating the control unit 200 is located, and are positioned further back than the front of the first housing 101a. This reduces the impact of fan noise on the user operating the image forming apparatus 100 from the front of the device. In addition, it is possible to suppress an increase in the size of the front side of the first housing 101a relative to the transport path of the recording material S, and to suppress protrusion toward the front side relative to the second housing 101b and the paper feed device (not shown) and finisher device 300 connected upstream and downstream of the image forming apparatus 100. This increases the degree of design freedom. Furthermore, by exhausting air from the rear of the first housing 101a and drawing in air through intake ports 171a and 172a provided on the front and sides of the first housing 101a, it is possible to draw in air that is not affected by the heat from the exhaust, thereby suppressing a decrease in cooling efficiency.

[0034] Figure 5 shows an example of the airflow configuration for the image forming section Pa. In the charger 2a, the surface of the photosensitive drum 3a is charged by ionizing the air surrounding the charging wire 502 through corona discharge, thereby generating ions. At that time, the charger 2a generates not only ions but also ozone. However, ozone is prone to corroding components of the charger 2a, such as a stainless steel grid (not shown), so it needs to be recovered. Therefore, in order to send the ozone to the ozone recovery filter 503a by air for recovery, a blower duct 501 that supplies air to the charger 2a and an exhaust duct 503 that exhausts the air to the outside via the ozone recovery filter 503a are provided near the charger 2a.

[0035] The developing unit 1a is equipped with an aluminum heatsink 505 and a cooling duct 504. Air supplied from the outlet 207b located in the inner cover unit (described later) absorbs heat as it passes through the cooling duct 504 and then the heatsink 505, thereby cooling the developing unit 1a. The air that has passed through the cooling duct 504 is exhausted outside the unit by an exhaust fan (not shown).

[0036] As shown in Figure 6, an inner cover unit 125 is provided on the front of the first housing 101a, inside the left front door 170a and the right front door 170b, so as to cover the image forming units Pa to Pd which are arranged in parallel inside the first housing 101a. The inner cover unit 125 is intended to prevent the user from accidentally touching the power supply unit, movable parts, etc. of the image forming units Pa to Pd which are arranged in parallel inside the first housing 101a when the front doors (170a, 170b) are opened. However, the inner cover unit 125 is detachably attached to the first housing 101a so that a service technician can perform maintenance work.

[0037] In this embodiment, the image forming units Pa and Pb are supported by the first housing 101a at a position opposite the closed left front door 170a, and the image forming units Pc and Pd are supported by the first housing 101a at a position opposite the closed right front door 170b. In other words, the image forming units Pa and Pb are positioned to the left of the center when viewed from the front, and the image forming units Pc and Pd are positioned to the right of the center when viewed from the front.

[0038] <Inner cover unit> Next, the inner cover unit 125 will be described using Figures 1, 3(a), 3(b), and 6, and Figures 7(a) to 7(c). Figure 7(a) is a schematic diagram showing the inner surface of the inner cover unit 125 of the first embodiment. As shown in Figure 7(a), the inner cover unit 125 of this embodiment has a first inner cover 201 and a second inner cover 202 arranged adjacent to the first inner cover 201 in the left-right direction (longitudinal direction). For example, the first inner cover 201 is arranged to cover the image forming sections Pa and Pb, and the second inner cover 202 is arranged to cover the image forming sections Pc and Pd.

[0039] For example, the inner cover unit 125 is formed to have a horizontal length of "1253 mm" and a vertical (short side) length of "225 mm" to match the first housing 101a. When the inner cover unit 125 is formed by a first inner cover 201 and a second inner cover 202, the first inner cover 201 is formed to have a horizontal length of "675 mm" and a vertical length of "225 mm", and the second inner cover 202 is formed to have a longitudinal length of "578 mm" and a short side length of "225 mm".

[0040] The first inner cover 201 and the second inner cover 202 described above are integrated by reinforcing plates 211 and 212. In this embodiment, both reinforcing plates 211 and 212 are positioned across the first inner cover 201 and the second inner cover 202, and are integrated by being fixed to both the first inner cover 201 and the second inner cover 202. Reinforcing plates 211 and 212 are made of metal and are positioned so as to extend in the left-right direction, and are positioned above and below the center in the vertical direction. These reinforcing plates 211 and 212 reinforce the resin first inner cover 201 and the second inner cover 202, and also suppress warping of the first inner cover 201 and the second inner cover 202.

[0041] The first inner cover 201 and the second inner cover 202 each have multiple ducts. These multiple ducts in the first inner cover 201 and the second inner cover 202 are formed in a suitable shape to efficiently deliver air to the destination of the airflow within the first housing 101a. By integrating the first inner cover 201 and the second inner cover 202 with the ducts, a flow path can be formed while minimizing an increase in size.

[0042] The first inner cover 201 has a first cover surface 2011 on the image forming unit side (inside) opposite to the left front door 170a, which serves as a first duct for guiding air drawn in from the outside to the image forming unit, and a part of duct 210. Ducts 203, 204, 207, 208, 209, and 210 each have an inlet 203a, 204a, 207a, 208a, 209a, and 210a for bringing air in, and an outlet 203b, 204b, 207b, 208b, 209b, and 210b for releasing air. As shown in the figure, the duct 210 is formed spanning a first inner cover 201 and a second inner cover 202, with an inlet 210a on the first inner cover 201 and an outlet 210b on the second inner cover 202.

[0043] On the other hand, the second inner cover 202 has a second cover surface 2012 on the image forming unit side (inside) opposite the right front door 170b, which has a plurality of ducts 205 and 206 and a part of duct 210 as a second duct that guides air drawn in from the outside to the image forming unit. Ducts 205 and 206 each have an inlet 205a and 206a for bringing air in and an outlet 205b and 206b for letting air out.

[0044] In this embodiment, duct 203 is for charging unit 2a, duct 204 is for charging unit 2b, duct 207 is for developing unit 1a, and ducts 208-210 are for guiding air to developing units 1b-1d, respectively. Air is supplied to these ducts 203, 204, 207, 208, 209, and 210 from the left-side air supply unit 124 shown in Figure 3. Additionally, duct 205 is for supplying air to charging unit 2d, and duct 206 is for supplying air to charging unit 2c. Air is supplied to these ducts 205 and 206 from the right-side air supply unit 126 shown in Figure 4.

[0045] Next, the configuration of the duct in the first inner cover 201 described above will be explained using duct 203 as a representative example. As shown in Figure 7(b), duct 203 is composed of a pair of ribs 2031 that protrude from the first cover surface 2011 of the first inner cover 201 and extend opposite to each other, and a duct cover 203c provided to cover the opening of the pair of ribs 2031. The pair of ribs 2031 (first rib, second rib) are extended in an appropriate shape so as to form walls that protrude from the first cover surface 2011 and face each other, extending between the left-side air blower unit 124 and the charger 2a. The duct cover 203c (first duct cover, second duct cover) is formed to fit with the pair of ribs 2031. In this way, the pair of ribs 2031 integrally formed on the inner surface of the first inner cover 201 are covered by the duct cover 203c, which is a separate component, thereby forming the duct 203 in the first inner cover 201.

[0046] Although not shown in the diagram here, the configuration of the duct in the second inner cover 202 is similar. For example, the duct 205 may be composed of a pair of second ribs that protrude from the second cover surface 2012 of the second inner cover 202 (see Figure 7(a)) and extend opposite to each other, and a separate duct cover provided to cover the openings of the pair of second ribs.

[0047] Next, we will describe the duct 210 that spans the first inner cover 201 and the second inner cover 202. As mentioned above, since the first inner cover 201 and the second inner cover 202 are manufactured separately, the duct 210 is divided into the first inner cover 201 side and the second inner cover 202 side. A portion of the duct 210 provided on the first inner cover 201 side will be referred to as duct 210d (first duct), and a portion of the duct 210 provided on the second inner cover 202 side will be referred to as duct 210f (second duct). In this embodiment, a connecting portion 210c is provided to connect these ducts 210d and duct 210f so that air can be guided from one to the other.

[0048] In this embodiment, as shown in Figure 7(c), a fitting portion 210e is formed at the end of the duct 210d, projecting toward the duct 210f, as the connecting portion 210c. The fitting portion 210e is provided so as to be able to fit into the tip of the duct 210f, and the duct 210d and duct 210f are connected when the fitting portion 210e fits into the tip of the duct 210f. More specifically, a pair of ribs 2101 formed on the first inner cover 201 and a pair of ribs 2102 formed on the second inner cover 202 are connected. To enable this, the fitting portion 210e is formed so that the ribs 2101 do not interfere with the ribs 2102, and are positioned opposite each other at a narrower distance than the distance between the ribs 2102. The duct cover described above is then attached to the ribs 2101 and ribs 2102, which are connected via the fitting portion 210e.

[0049] Furthermore, as shown in Figure 7(a), if the reinforcing plate 212 is positioned to overlap the ducts 208, 209, and 210 when viewed from the rear, the duct cover described above may be integrally provided on the reinforcing plate 212.

[0050] The first inner cover 201 and the second inner cover 202 described above are integrally and detachably provided to the first housing 101a. In this embodiment, as shown in Figure 7(a), there is a first fixing part 220 for detachably fixing the first inner cover 201 to the first housing 101a, and a second fixing part 221 for detachably fixing the second inner cover 202 to the first housing 101a.

[0051] In this embodiment, the inner cover unit 125, which integrates the first inner cover 201 and the second inner cover 202, can be positioned at a predetermined location on the first housing 101a via the first fixing part 220 and the second fixing part 221. Furthermore, the inner cover unit 125 installed by the user or worker can be fixed to the first housing 101a. This point will be explained below with reference to Figures 2(a) and 7(a), and using Figures 8(a) to 8(d). However, since the first fixing part 220 and the second fixing part 221 have similar configurations, the explanation below will use the second fixing part 221, which fixes the second inner cover 202, as an example.

[0052] As shown in Figure 8(a), the second fixing part 221 has a mounting base 214 and a lever part 215. The mounting base 214 is fixed to the first housing 101a. The mounting base 214 has a pin 214a that protrudes toward the front, and as shown in Figure 8(b), the inner cover unit 125 is positioned in a predetermined position on the first housing 101a by passing the pin 214a through the positioning hole of the second inner cover 202. The predetermined position here is a position in which the inlets and outlets of the multiple ducts of the inner cover unit 125 can efficiently guide air toward the left blower unit 124, the right blower unit 126, the chargers 2a to 2d, and the developers 1a to 1d.

[0053] The lever portion 215 is rotatably mounted on the second inner cover 202. The lever portion 215 has a shaft portion 216 that extends from the front to the back through a through hole formed in the second inner cover 202. As shown in Figures 8(b) and 8(c), a stopper 217 is formed at the tip of the shaft portion 216, intersecting the shaft portion 216. The lever portion 215 is movable between a locked position that fixes the second inner cover 202 as shown in Figures 8(a) and 8(b), and a released position that releases the fixing of the second inner cover 202 as shown in Figures 8(c) and 8(d).

[0054] In other words, when fixing the second inner cover 202 to the first housing 101a, the user positions the second inner cover 202 via the pin 214a and then rotates the lever portion 215 in the locking direction. This causes the shaft portion 216 of the lever portion 215 to rotate, and as shown in Figure 8(d), the stopper 217 is moved to a position where it overlaps with the mounting base 214 when viewed from the front, or in other words, the mounting base 214 is sandwiched between the second inner cover 202 and the stopper 217. If the user tries to move the second inner cover 202 to face forward in this state, as shown in Figure 8(c), the stopper 217 hits the mounting base 214, and the second inner cover 202 cannot be moved. If the user wants to move the second inner cover 202 to face forward, the user needs to rotate the lever portion 215 in the opposite direction to the locking direction, and move it to a position where the stopper 217 does not overlap with the mounting base 214 when viewed from the front, as shown in Figure 8(b). In this way, the inner cover unit 125 is fixed in a locked state so that it cannot be removed from the first housing 101a.

[0055] As described above, in this embodiment, the inner cover unit 125 is constructed by dividing it into a first inner cover 201 and a second inner cover 202 made of resin. Multiple ducts are formed in the first inner cover 201 and the second inner cover 202. The user can attach the inner cover unit 125, which integrates the first inner cover 201 and the second inner cover 202, to the first housing 101a. By dividing the inner cover unit 125 into the first inner cover 201 and the second inner cover 202 in this way, the longitudinal dimensions of each individual part, the first inner cover 201 and the second inner cover 202, can be shortened. That is, the first inner cover 201 and the second inner cover 202, which are less prone to warping due to their shorter longitudinal dimensions, can be manufactured separately, and by integrating these first inner cover 201 and second inner cover 202, an inner cover unit 125 that is less prone to warping can be formed. Because warping is less likely to occur, the user can easily attach the inner cover unit 125 to the first housing 101a, and when the inner cover unit 125 is attached, the duct is positioned correctly relative to the image forming section Pa~Pd, which is the destination of the airflow.

[0056] Furthermore, when manufacturing the first inner cover 201 and the second inner cover 202 by injection molding, a small processing machine can be used, thus reducing manufacturing costs. This is because when injection molding a single rectangular inner cover (with a large difference between the long and short sides), it is necessary to use a large processing machine corresponding to the long side. However, it is also difficult to arrange large parts at the same time, resulting in wasted space during molding and poor space efficiency. As a result, the high labor costs of the large molding machine are significantly reflected in the cost of the individual parts. In addition, a single rectangular part creates wasted space for storage and transportation, making it easier to add management and transportation costs. Therefore, dividing the part helps to control costs.

[0057] [Second Embodiment] Next, the inner cover unit 125A of the second embodiment will be described using Figures 9(a) to 9(c). In the following description of the inner cover unit 125A of the second embodiment, the same reference numerals are used for components that are the same as those of the inner cover unit 125 of the first embodiment (see Figure 7(a)) described above, and the explanation will be simplified or omitted.

[0058] As shown in Figure 9(a), in the inner cover unit 125A, first metal reinforcing plates 311 and 313 are placed on the first inner cover 201 and fixed to the first inner cover 201. Second metal reinforcing plates 312 and 314 are placed on the second inner cover 202 and fixed to the second inner cover 202. The first reinforcing plates 311 and 313 reinforce the first inner cover 201 and suppress warping. The second reinforcing plates 312 and 314 reinforce the second inner cover 202 and suppress warping.

[0059] Thus, unlike the inner cover unit 125 of the first embodiment, the inner cover unit 125A does not have a reinforcing plate that spans the first inner cover 201 and the second inner cover 202. Therefore, the first inner cover 201 and the second inner cover 202 can each be attached to and detached from the first housing 101a independently, and the inner cover unit 125A is mounted to the first housing 101a by fixing the first inner cover 201 and the second inner cover 202 separately.

[0060] In order to fix the first inner cover 201 to the first housing 101a, in addition to the first fixing part 220 described above, a mounting base 316 having a pin 316a is provided on the first housing 101a. Furthermore, in order to fix the second inner cover 202 to the first housing 101a, in addition to the second fixing part 221 described above, a mounting base 318 having a pin 318a is provided on the first housing 101a. That is, the first inner cover 201 is positioned at a predetermined position on the first housing 101a by being inserted through the pin 220a of the first fixing part 220 and the pin 316a of the mounting base 316. The second inner cover 202 is positioned at a predetermined position on the first housing 101a by being inserted through the pin 214a of the second fixing part 221 and the pin 318a of the mounting base 318.

[0061] As shown in Figure 9(b), a sealing member 330 is provided at the joint between duct 210d and duct 210f. The sealing member 330 is provided on at least one of duct 210d and duct 210f and seals and fills the gap at the joint between duct 210d and duct 210f to prevent air leakage from the joint between duct 210d and duct 210f. The sealing member 330 is, for example, a sponge. Note that duct 210d and duct 210f may also be connected by the fitting portion 210e (see Figure 7(c)) described above.

[0062] However, in that case, the order in which the first inner cover 201 and the second inner cover 202 are removed depends on which of the first inner cover 201 and the second inner cover 202 has the fitting portion 210e. For example, as shown in Figure 7(c), if the fitting portion 210e is provided on the duct 210d on the first inner cover 201 side, the user cannot open the first inner cover 201 without first opening the second inner cover 202. In contrast, if the ducts 210d and 210f are connected only via the sealing member 330, there is no specific order for removing the first inner cover 201 and the second inner cover 202, and it becomes possible to remove only one of them. This allows, for example, if only the image forming section Pa requires maintenance, only the first inner cover 201 can be removed to perform maintenance on the image forming section Pa. In this way, the workability during maintenance of the image forming sections Pa to Pd, etc., covered by the first inner cover 201 and the second inner cover 202 can be improved.

[0063] Furthermore, ducts 210d and 210f may be connected via a relay duct 350, which is a connecting portion 210c, as shown in Figure 9(c). The relay duct 350 is fixed to the first housing 101a. When the first inner cover 201 and the second inner cover 202 are attached to the first housing 101a, one end of the relay duct 350 is fitted and connected to duct 210d, and the other end is fitted and connected to duct 210f, thereby forming a flow path that guides air from duct 210d to duct 210f. Sealing members 330 are provided at both ends of the relay duct 350, and the sealing members 330 seal and fill the gaps to prevent air leakage from the joints between the relay duct 350 and ducts 210d and 210f. By configuring it in this way, the gaps at the duct joints can be reduced compared to the configuration shown in Figure 9(b), thereby suppressing airflow loss.

[0064] In this second embodiment, the user can attach the inner cover unit 125A to the first housing 101a by separately attaching the first inner cover 201 and the second inner cover 202. That is, before attachment, the inner cover unit 125A is divided into the first inner cover 201 and the second inner cover 202, and after attachment, the integrated inner cover unit 125A is provided. This makes it easier for the user to attach the inner cover unit 125A to the first housing 101a than attaching the inner cover unit 125 (see Figure 7(a)), which is an integrated inner cover unit 121 and the second inner cover 202, before attachment.

[0065] [Other embodiments] In the second embodiment described above, an example was shown in which the first inner cover 201 and the second inner cover 202 are fixed to the first housing 101a in a closed state via fixing parts (220, 221) and mounting bases (316, 318), but the invention is not limited to this. For example, the first inner cover 201 and the second inner cover 202 may be provided so as to be openable and closable relative to the first housing 101a. Hereinafter, the case in which the first inner cover 201 and the second inner cover 202 are provided so as to be openable and closable will be described using Figures 10(a) to 10(c). However, components that are the same as those in the inner cover unit 125A of the second embodiment (see Figure 9(a)) are denoted by the same reference numerals, and their description will be simplified or omitted.

[0066] As shown in Figure 10(a), the first inner cover 201 has a first pivot shaft 401a at one end and is provided to rotate around the first pivot shaft 401a relative to the first housing 101a so as to be able to open and close. The first pivot shaft 401a is attached to a hinge support plate 401 fixed to the first housing 101a. When the first inner cover 201 is closed, it is inserted through the pin 316a of the mounting base 316 and positioned at a predetermined position on the first housing 101a.

[0067] On the other hand, the second inner cover 202 has a second pivot shaft 402a at the end furthest from one end of the first inner cover 201, and is provided to rotate around the second pivot shaft 402a relative to the first housing 101a to open and close. The second pivot shaft 402a is attached to a hinge support plate 402 fixed to the first housing 101a. When the second inner cover 202 is closed, it is inserted through the pin 318a of the mounting base 318 and positioned at a predetermined position on the first housing 101a.

[0068] As shown in Figure 10(b), with the front doors (170a, 170b) open, the first inner cover 201 and the second inner cover 202 open and close independently in the left and right directions. When the first inner cover 201 and the second inner cover 202 are provided to be openable and closable in this way, it is preferable that the duct 210d and duct 210f are connected and disconnected in accordance with the opening and closing using the relay duct 350 described above, as shown in Figure 10(c).

[0069] Ducts 210d and 210f may be connected by the fitting portion 210e (see Figure 7(c)) described above. However, in that case, the opening and closing order of the first inner cover 201 and the second inner cover 202 is determined by whether the fitting portion 210e is provided on the first inner cover 201 or the second inner cover 202. For example, as shown in Figure 7(c), if the fitting portion 210e is provided on the duct 210d on the first inner cover 201 side, the user cannot open the first inner cover 201 without first opening the second inner cover 202.

[0070] In contrast, when the relay duct 350 is provided, there is no specific opening and closing sequence for the first inner cover 201 and the second inner cover 202, making it possible to open only one of them. This allows, for example, if only the image forming section Pa requires maintenance, only the first inner cover 201 can be opened to perform maintenance on the image forming section Pa. This improves the workability during maintenance of the image forming sections Pa to Pd, etc., which are covered by the first inner cover 201 and the second inner cover 202.

[0071] Here, we have shown an example where the first inner cover 201 and the second inner cover 202 open and close separately in the left-right direction, but the opening and closing direction is not limited to this. The first inner cover 201 and the second inner cover 202 may both be able to open and close in the same direction in the left-right direction, or they may be able to open and close in the up-down direction. Furthermore, the first inner cover 201 and the second inner cover 202 may be able to open and close as a single unit.

[0072] In the embodiments described above, the first inner cover 201 covers the image forming units Pa and Pb, and the second inner cover 202 covers the image forming units Pc and Pd, but the invention is not limited to this. For example, among the multiple image forming units Pa to Pb, only the image forming unit Pa (first image forming unit) located at the one end in the longitudinal direction (the direction in which the image forming units Pa to Pb are arranged) may be covered by the first inner cover 201, while the other image forming units Pb, Pc, and Pk, including the image forming unit Pk (second image forming unit) located at the other end in the longitudinal direction, may be covered by the second inner cover 202. [Explanation of symbols]

[0073] 1a (1b, 1c, 1d)... Developer, 2a (2b, 2c, 2d)... Charger, 3a (3b, 3c, 3d)... Photoreceptor, 100... Image forming apparatus, 101a... Housing (first housing), 170a (170b)... Outer cover (left front door, right front door), 201... First inner cover, 202... Second inner cover, 203 (204, 207, 208, 209, 210d)... First duct, 203c... First duct cover (second duct cover, duct cover), 205 (206, 21 0f)...Second duct, 210c...Connection part, 210e...Matching part, 211(212)...Reinforcement plate, 220...First fixing part, 221...Second fixing part, 311(313)...First reinforcement plate, 312(314)...Second reinforcement plate, 350...Intermediate duct, 401a...First pivot shaft, 402a...Second pivot shaft, 2011...First cover surface, 2012...Second cover surface, 2031...First rib (second rib, rib), Pa(Pb, Pc, Pd)...Image forming unit (image forming part), S...Recording material

Claims

1. A housing and an image forming unit provided in the housing and configured to form a toner image on a recording material; an outer cover provided on the housing in an openable and closable manner; a first inner cover made of resin and arranged to face the inner surface of the outer cover in a closed state; a second inner cover made of resin and arranged to face the inner surface of the outer cover in a closed state; a portion of the first inner cover at least partially defines a first duct; A portion of the second inner cover at least partially defines a second duct.

1. An image forming apparatus comprising:

2. The image forming unit includes a first image forming unit and a second image forming unit which form toner images of different colors, the first duct guides air drawn in from the outside to the first image forming unit, The second duct guides air drawn in from the outside to the second image forming unit.

2. The image forming apparatus according to claim 1,

3. A first fan for drawing air from the outside into the first duct; A second fan for drawing air from the outside into the second duct.

3. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

4. The first duct is formed on a first cover surface of the first inner cover opposite to the outer cover, The second duct is formed on a second cover surface of the second inner cover opposite to the outer cover.

4. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

5. The first inner cover has a pair of first ribs that protrude from the first cover surface and extend opposite to each other, the pair of first ribs and a first duct cover provided to cover openings of the pair of first ribs form the first duct; The second inner cover has a pair of second ribs that protrude from the second cover surface and extend opposite to each other, The pair of second ribs and a second duct cover provided to cover the openings of the pair of second ribs form the second duct.

5. The image forming apparatus according to claim 4.

6. a connecting portion for connecting the first duct and the second duct so as to be able to guide air from one to the other; 6. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

7. The connection portion is a fitting portion provided at a tip portion of the first duct so as to be capable of being fitted with the second duct.

7. The image forming apparatus according to claim 6,

8. the connection portion is provided in the housing, and when the first inner cover and the second inner cover are arranged, one end side is connected to the first duct and the other end side is connected to the second duct, forming an intermediate duct that guides air from one of the first duct and the second duct to the other.

7. The image forming apparatus according to claim 6,

9. the first inner cover has a first rotation shaft at one end and is provided so as to be rotatable about the first rotation shaft relative to the housing to be opened and closed; The second inner cover has a second rotation shaft at an end farther from the one end, and is provided so as to be rotatable about the second rotation shaft relative to the housing to be opened and closed.

9. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

10. a metal reinforcing plate disposed across the first inner cover and the second inner cover and fixed to the first inner cover and the second inner cover; 10. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

11. a first reinforcing plate made of metal and fixed to the first inner cover; A second reinforcing plate made of metal is disposed on the second inner cover and fixed to the second inner cover.

11. The image forming apparatus according to claim 1,

12. A first fixing portion that detachably fixes the first inner cover to the housing; and a second fixing portion that detachably fixes the second inner cover to the housing.

12. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

13. the image forming unit includes a photoconductor, a charger for charging the photoconductor, an exposure unit for exposing the charged photoconductor to light to form an electrostatic latent image, and a developing unit for developing the electrostatic latent image formed on the photoconductor into a toner image with a developer; The first duct and the second duct guide air drawn in from the outside to the charger.

13. The image forming apparatus according to claim 1, wherein the image forming apparatus is a multi-layered image forming apparatus.

14. the image forming unit includes a photoconductor, a charger for charging the photoconductor, an exposure unit for exposing the charged photoconductor to light to form an electrostatic latent image, and a developing unit for developing the electrostatic latent image formed on the photoconductor into a toner image with a developer; the first duct and the second duct guide air drawn in from the outside to the developing unit; 13. The image forming apparatus according to claim 1, wherein the image forming apparatus is a multi-layered image forming apparatus.

15. The image forming unit includes a first image forming unit and a second image forming unit which form toner images of different colors, the first inner cover is disposed opposite an inner surface of the outer cover in a closed state and opposite the first image forming unit; the second inner cover is disposed facing the inner surface of the outer cover in a closed state and facing the second image forming unit; 15. The image forming apparatus according to claim 1,

Images