Image forming apparatus

Abstract

To improve workability of maintenance of at least some maintenance components of an image forming unit in an inner cover unit provided between an outer cover and the image forming unit.SOLUTION: An inner cover unit is provided with an area for forming ducts for sending outside air to an image forming unit and an area for forming openings for inserting and withdrawing at least part of the image forming unit, and small covers for covering the openings are removably attached to the inner cover unit.SELECTED DRAWING: Figure 5

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, there has been proposed an image forming apparatus including an openable and closable exterior cover and an inner cover provided inside the exterior cover in a closed state (Patent Document 1). Inside the inner cover, a plurality of image forming units having a photosensitive drum, a charger, a developing device, etc. are provided. The inner cover is provided to prevent accidental contact with the power supply unit, movable parts, etc. of the image forming unit when the user opens the exterior cover to remove a jammed recording material in the case of a so-called jam where the recording material is not discharged and gets stuck in the middle of the conveyance path.

[0003] In addition, an 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 unit having, for example, a charger and a developing device. The reason for blowing air toward the image forming unit is to collect discharge products such as ozone generated by the charging of the charger, and also to suppress the temperature rise of the developing device accompanying the toner stirring 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 apparatuses for commercial printing that can form toner images on a large amount of recording material in a short time are being used. In such apparatuses, the amount of discharge product generated from the charger tends to be large, and the developer tends to heat up easily, so large fans that can draw in and circulate a large amount of air are sometimes used.

[0006] However, in recent years, there has been a demand for miniaturization even in image forming machines for commercial printing. Consequently, if there is not enough space to install a fan on the front side of the image forming unit within the enclosure, the fan may be positioned outside the image forming unit in the width direction of the image forming machine.

[0007] In this case, it is conceivable to install ducts that guide the air drawn in by the fan to each image forming unit in the relatively spacious resin inner cover. However, when performing maintenance on any of the parts contained within each image forming unit, it was necessary to remove and reattach the inner cover that covers multiple image forming units and has the ducts each time maintenance was performed. Therefore, there was a risk of reduced work efficiency when performing maintenance on the image forming units.

[0008] Therefore, in view of the above problems, the present invention aims to provide an image forming apparatus that can suppress a decrease in workability during maintenance of image forming units, even when a duct is provided in the inner cover that covers a plurality of image forming units. [Means for solving the problem]

[0009] An image forming apparatus according to one embodiment of the present invention is an image forming apparatus for forming an image on a sheet, comprising: a first image forming unit, one of a plurality of image forming units, having a first photoreceptor, a first charging unit for charging the first photoreceptor, and a first developing unit for developing the electrostatic latent image formed on the first photoreceptor using toner; a second image forming unit, one of the plurality of image forming units, having a second photoreceptor, a second charging unit for charging the second photoreceptor, and a second developing unit for developing the electrostatic latent image formed on the second photoreceptor using toner; a first cover that forms part of the exterior of the image forming apparatus and is openable and closable; and a unit provided between the first cover and the plurality of image forming units in the direction of the rotation axis of the first photoreceptor, for the plurality of image forming units unit A second cover that covers the second cover, and provided on the second cover, The first A first duct guides air drawn in from outside the image forming apparatus through an air intake to the first image forming unit, A first fan provided outside the plurality of image forming units in the arrangement direction of the plurality of image forming units, the first fan draws in air to be supplied to the first duct via the first air intake, Provided in the second cover, The second A second duct guides air drawn in from outside the image forming apparatus through an air intake to the second image forming unit, A second fan provided on the opposite side of the first fan from the plurality of image forming units in the arrangement direction of the plurality of image forming units, the second fan draws in air to be supplied to the second duct via the second air intake, The invention is characterized by comprising: a third cover detachably provided to the second cover so as to cover an opening in the second cover from which at least a portion of the first image forming unit can be inserted and removed; and a third cover detachably provided to the second cover. [Effects of the Invention]

[0010] According to the present invention, even with a configuration in which ducts are provided in the inner cover that covers multiple image forming units, it is possible to provide an image forming apparatus that can suppress a decrease in workability during maintenance of the image forming units. [Brief explanation of the drawing]

[0011] [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 cross-sectional view of the image forming unit. [Figure 6] A perspective view showing the left front door and the right front door exterior cover in the open position. [Figure 7] A schematic diagram showing the configuration of the inner cover unit. [Figure 8] Cross-sectional view showing the procedure for removing the primary charger. [Figure 9] Cross-sectional view showing the procedure for removing the primary charger. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings. However, the dimensions, materials, shapes, and relative arrangements of the components described in the following embodiments should be appropriately changed depending on the configuration of the device to which the present invention is applied and various conditions, and the scope of the present invention is not intended to be limited to those.

[0013] <First Embodiment> <Image Forming System> The schematic configuration of the image forming system equipped with the image forming apparatus of this embodiment will be described with reference to Figure 1. Figure 1 is a schematic diagram showing the image forming system 100S according to this embodiment. The image forming system 100S comprises an image forming apparatus 100 and a finisher 600. The image forming apparatus 100 is the image forming apparatus of this embodiment, and the finisher 600 is the sheet processing apparatus of this embodiment. The image forming apparatus 100 and the finisher 600 are connected so as to be able to receive a sheet S. In this embodiment, the finisher 600 is an optional 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 sheet S on which the toner image has been fixed by the image forming apparatus 100. The image forming apparatus 100 and the finisher 600 are connected to each other so as to be able to send and receive data through a communication interface that enables serial communication and parallel communication.

[0014] The housing 101 of the image forming apparatus 100 has a first housing 101a and a second housing 101b. The first housing 101a is provided with an image forming engine 102, an intermediate transfer belt 106 (to be described later), a storage 113, and the like.

[0015] On the other hand, the second housing 101b is provided with a first fixing device 150, a second fixing device 160, a reverse conveyance path 135 (to be described later), and the like.

[0016] The image forming unit 102 includes a plurality of image forming units 120, 121, 122, 123 that form toner images of each color of yellow, magenta, cyan, and black, and an intermediate transfer belt 106. In each of the image forming units 120 to 123, only the color of the toner used is different, and the configurations are common. Therefore, here, the image forming unit 120 will be taken as an example to explain the detailed configuration.

[0017] The image forming unit 102 has a drum-shaped photoreceptor 105a, a charger 111a, a developer 112a, and a laser scanner unit 107a. The charger 111 ionizes the air around a charging wire 502 (to be described later) by corona discharge to generate ions, thereby charging the photoreceptor 105a. The laser scanner unit 107a performs an exposure process on the photoreceptor 105a based on a command signal generated based on image data and transmitted to the laser scanner unit 107a.

[0018] Here, the laser scanner unit 107a has a laser driver that drives laser light emitted from a semiconductor laser (not shown). The laser light from the semiconductor laser is distributed in the main scanning direction by a rotating polygon mirror and guided to the photoreceptor 105a through a reflection mirror 109a. As a result, an electrostatic latent image corresponding to the image data is formed on the photoreceptor 105a. In the present embodiment, the laser scanner unit 107a has a dust-proof glass as a glass member, and forms an electrostatic latent image on the photoreceptor 105a by irradiating laser light through the dust-proof glass.

[0019] The developer unit 112a contains a developer containing toner and supplies charged toner particles to the photoreceptor 105a. As the toner particles adhere to the surface of the photoreceptor 105a according to the surface potential distribution, the electrostatic latent image supported on the photoreceptor 105a is visualized as a toner image. The toner image supported on the photoreceptor 105a is transferred (primary transfer) to an intermediate transfer belt 106 to which a voltage opposite to the normal charging polarity of the toner is applied. In this embodiment, the image forming unit 120 is an example of a first image forming unit, and the image forming unit 123 is an example of a second image forming unit. Also, the photoreceptor 105a is an example of a first photoreceptor, the charger 111a is an example of a first charging unit, and the developer unit 112a is an example of a first developing unit. Also, the photoreceptor 105d is an example of a second photoreceptor, the charger 111d is an example of a second charging unit, and the developer unit 112a is an example of a second developing unit.

[0020] When forming a color image, the toner images formed by the four image forming units 120 to 123 are superimposed on the intermediate transfer belt 106 through multiple transfers, thereby forming a full-color toner image on the belt.

[0021] Meanwhile, the feeding mechanism feeds sheets S one by one from a storage compartment 113, which is retractably inserted into the housing 101 of the image forming apparatus 100, toward the transfer roller 114. The toner image supported on the intermediate transfer belt 106, which is an intermediate transfer body, is transferred (secondary transfer) to the sheet S by the transfer roller 114.

[0022] Around the intermediate transfer belt 106 are an image formation start position detection sensor 115 for determining the printing start position when performing image formation, a feed timing sensor 116 for determining the feeding timing of the sheet S, and a density sensor 117. The density sensor 117 measures the density of the patch image supported on the intermediate transfer belt 106. The printer controller adjusts the operating conditions of the optical processing mechanism (for example, the charging target potential of the charger 111a and the bias voltage setting of the developer 112a) based on the detection result of the density sensor 117.

[0023] The fixing mechanism of this embodiment is composed of a first fuser 150 and a second fuser 160. The first fuser 150 includes a fixing roller 151 for applying heat to the sheet S, a pressure belt 152 for pressing the sheet S against the fixing roller 151, and a first post-fixing sensor 153 for detecting the completion of the fixing process by the first fuser 150. Each roller, including the fixing roller 151, is a hollow roller and has a heater inside. The first fuser 150 applies heat and pressure to the toner image on the sheet while conveying the sheet S by clamping it between the fixing roller 151 and the pressure belt 152, which are a pair of rotating bodies. As a result, the toner particles melt and then solidify, fixing the image to the sheet S.

[0024] The second fuser 160 is positioned downstream of the first fuser 150 in the sheet S transport path. The second fuser 160 has the function of increasing the glossiness of the image that has been fixed by the first fuser 150 and ensuring the fixation of the image to the sheet S. Similar to the first fuser 150, the second fuser 160 has a pair of rotating bodies, a fixing roller 161 and a pressure roller 162, which heat and pressurize the sheet S while transporting it, and a second post-fixing sensor 163 that detects the completion of the fixing process by the second fuser 160.

[0025] In addition, depending on the type of sheet S, it may not be necessary to pass through the second fuser 160. In such cases, the image forming apparatus 100 has a bypass transport path 130 for discharging the sheet S without passing through the second fuser 160 in order to reduce energy consumption. The sheet S sent out from the first fuser 150 is guided by the first switching flap 131 to either the second fuser 160 or the bypass transport path 130.

[0026] The sheet S that has passed through the second fuser 160 or the bypass transport path 130 is guided by the second switching flap 132 to either the discharge transport path 139 or the reversal transport path 135. The sheet S that has been transported to the reversal transport path 135 has its position detected by the reversal sensor 137, and the leading and trailing ends in the sheet transport direction are swapped by a switchback operation performed by the reversal unit 136. In the case of double-sided printing, the sheet S on which the image has been formed on the first side is transported again towards the transfer roller 114 via the re-transport path 138 with its leading and trailing ends swapped by the reversal unit 136, and an image is formed on the second side. The sheet S on which image formation for single-sided printing has been completed, or the sheet S on which image formation for the second side in double-sided printing has been completed, is discharged to the outside of the image forming apparatus 100 by the discharge roller 139a provided in the discharge transport path 139. A switching flap 134 is provided between the reversal transport path 135 and the discharge transport path 139, which can guide the sheet S, which has been switched back by the reversal unit 136, toward the discharge transport path 139, and is configured to allow selection of the front and back sides of the sheet S when it is discharged from the image forming apparatus. An image reading device 190 that reads image information from the original is installed on top of the image forming apparatus 100. The sheet S discharged from the image forming apparatus 100 by the discharge roller 139a is sent to the finisher 600. The sheet S sent to the finisher 600 is subjected to predetermined processing by a processing unit 601 provided inside the finisher 600, and then loaded as a finished product onto the tray 602a or tray 600b of the finisher 600. The processing by the processing unit 601 is, for example, binding processing to bind multiple sheets together, or punching processing to make holes in the sheets.

[0027] Next, the airflow configuration in the first housing 101a of the image forming apparatus 100 will be explained with reference to Figure 1 and Figures 2 to 7. As shown in Figure 2(a), the front of the first housing 101a is provided with a left front door 170a and a right front door 170b, which are outer covers that constitute part of the exterior of the image forming apparatus 100. These doors are designed to open and close like double doors, with the left door 170a and the right front door 170b being approximately in the center in the left-right direction. In this embodiment, the left front door 170a and the right front door 170b are examples of first covers that constitute part of the exterior of the image forming apparatus 100.

[0028] Above the left front door 170a, an intake cover 171 is provided, which constitutes part of the exterior of the image forming apparatus 100, 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, which constitutes part of the exterior of the image forming apparatus 100, and an intake port 172a is formed on the right cover 172. In this embodiment, intake port 171a is an example of a first intake port, and intake port 172a is an example of a second intake port.

[0029] <Air blower unit> As shown in Figure 3, a left-side ventilation unit 124, which has a fan that draws in air from the intake port 171a and blows it out, is installed on the left side of the first housing 101a. For explanatory purposes, the housing 101a is shown with a dotted line, and the units that form the airflow are shown with solid lines. The left-side ventilation unit 124 has a left-side main duct 174, ventilation fans 174a and 174b, and a side duct 175. 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 200, which will be described later. Here, the left-side main duct 174 is a duct with a space formed inside that communicates with the intake port 171a.

[0030] The blower fans 174a and 174b and the side duct 175 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.

[0031] Furthermore, although not shown in this embodiment, four ventilation fans (not shown) are provided on the side opposite to the side of the left main body duct 174 where the side duct 175 is located. Each of these four fans (not shown) is capable of drawing in outside air from the image forming apparatus 100 through an air intake port 171a.

[0032] The side duct 175 is provided with ducts 175a to 175f inside for branching the airflow generated by each fan. Air drawn in by blower fans 174a, 174b and four other blower fans (not shown) is blown through ducts 175a to 175f (see dashed arrows) to the inner cover unit 200, which will be described later. In this embodiment, blower fan 174a is an example of a first fan provided outside the image forming units 120 to 123 in the arrangement direction of the multiple image forming units 120 to 123.

[0033] As shown in Figure 4, a right-side ventilation unit 126 is provided on the right side of the first housing 101a, which has a fan that draws in air from the intake port 172a and blows it out. The right-side ventilation unit 126 has a right-side main duct 177, ventilation fans 177a and 177b, and a through duct 178. 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 200, which will be described later. The right-side main duct 176 is provided with ducts 178a and 178b that communicate with the intake port 172a formed on the right side of the image forming apparatus 100 and branch the airflow from each fan. In this embodiment, the blower fan 177a is an example of a second fan provided on the opposite side of the blower fan 174a via the image forming units 120 to 123 in the arrangement direction of the plurality of image forming units 120 to 123.

[0034] The blower fans 177a and 177b and the through duct 178 are located on the right side of the right main duct 177. Specifically, the right main duct 177 has a communication port that connects to the blower fans 177a and 177b, and the air drawn in from the intake port 172a in accordance with the operation of the blower fans 177a and 177b passes through the inside of the right main duct 177. 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 178 is provided with ducts 178a and 178b that branch the airflow generated by each fan inside. The through duct 177 and the blower fans 177a and 177b are connected so that the air that has passed through the blower fans 177a and 177b passes through the ducts 178a and 178b (see dashed arrows). In this embodiment, the blower fans 174a, 174b, 177a, and 177b are, for example, centrifugal fans.

[0035] As described above, in this embodiment, as shown in Figures 3 and 4, multiple blower fans for drawing in air from intake ports 171a and 172a are arranged on the right and left sides of the first housing 101a. These are located far from the front where the user operating the control unit 180 is located. This reduces the impact of fan noise on the operator. Furthermore, it is possible to minimize the increase in the size of the front of the device body, thus increasing the design flexibility. In addition, although the exhaust air discharged from the rear of the device body becomes hot due to the heat discharge, by providing intake ports on the front and sides of the device, it is possible to suppress the intake of hot air discharged from the image forming apparatus 100. Therefore, it is possible to suppress a decrease in the cooling efficiency inside the image forming apparatus 100.

[0036] Figure 5 shows an example of the airflow configuration for the image forming unit 120. Note that in this embodiment, the airflow configurations for image forming units 121 to 123 are the same as those for image forming unit 120, so their explanation is omitted. Figure 5(a) is a cross-sectional view of the image forming unit 120 from the front. Figure 5(b) is a cross-sectional view of the image forming unit 120 from above.

[0037] The air discharged from the outlet 203b of the duct provided in the inner cover unit 200 (described later) reaches the primary charged duct 501 via the primary charged duct intake port 501a.

[0038] In the charger 111a, the surface of the photoreceptor 105 is charged by generating ions through corona discharge, which ionizes the air surrounding the charging wire 502. In this process, the charger 111a generates not only ions but also ozone. However, ozone needs to be recovered because it is prone to corroding components of the charger 111a, such as a stainless steel grid (not shown).

[0039] Therefore, in order to send ozone to the ozone recovery filter 503a by air for recovery, a blower duct 501 that blows air to the charger 2a and an exhaust duct 503 that exhausts air to the outside via the ozone recovery filter 505 are arranged near the charger 2a. An exhaust fan 560 is provided in the exhaust duct 503, and the air that has passed through the ozone filter 550 is discharged outside the machine through the exhaust port 503a by the rotation of the exhaust fan 560.

[0040] The developing unit 112a is also equipped with an aluminum heatsink 505 and a cooling duct 504. Air supplied from the outlet 207b of the duct 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).

[0041] <Internal cover unit> Next, the inner cover unit 200 in this embodiment will be described using Figures 6 and 7. Figure 6 is a perspective view showing the left front door 170a and the right front door 170b in an open state. Figure 7 is a schematic diagram showing the detailed configuration of the inner cover unit 200.

[0042] As shown in Figure 6, an inner cover unit 200 is provided inside the left front door 170a and the right front door 170b so as to cover the image forming units 120 to 123 which are arranged in parallel within the first housing 101a. In other words, further inside the inner cover unit 200 (at the back (+Y side) of the image forming apparatus 100), the image forming units 120 to 123 are arranged in parallel (shown by dotted lines). To put it another way, the inner cover unit 200 is provided between the left front door 170a and the right front door 170b and the image forming units 120 to 123 in the direction of the rotation axis of the photoreceptor 105a. In this embodiment, the inner cover unit 200 is an example of a second cover.

[0043] The inner cover unit 200 is designed to prevent users from accidentally touching power supply units, movable parts, etc., located in positions covered by the inner cover 200 when opening the left front door 170a and the right front door 170b. This prevents users from accidentally touching internal components such as movable parts or electrical wiring when opening the left front door 170a and the right front door 170b to clear paper jams or other issues. However, the inner cover unit 200 is detachably attached to the first housing 101a so that service personnel can perform maintenance work.

[0044] In this embodiment, the image forming units 120 and 121 are supported by the first housing 101a at a position opposite the closed left front door 170a, and the image forming units 122 and 123 are supported by the first housing 101a at a position opposite the closed right front door 170b. In other words, the image forming units 120 and 121 are positioned to the left of the center when viewed from the front, and the image forming units 122 and 123 are positioned to the right of the center when viewed from the front.

[0045] The inner cover unit 200 is a long rectangle in the width direction of the image forming apparatus 100 so as to cover the image forming units 120 to 123 which are arranged in parallel in the width direction (X direction) of the image forming apparatus 100. In this embodiment, the width direction (X direction) of the image forming apparatus is an example of the arrangement direction of the multiple image forming units 120 to 123.

[0046] Furthermore, the inner cover unit 200 is provided with multiple ducts for blowing air to the image forming units 120-123, as shown in Figure 7. Figure 7 is a schematic diagram showing the surface of the inner cover unit 200 that faces the image forming units 120-123.

[0047] The inner cover unit 200 is provided with ducts for blowing air toward the image forming unit 120, specifically a duct 203 for blowing air toward the charger 111a and a duct 207 for blowing air toward the developer 112a. The inner cover unit 200 is also provided with ducts for blowing air toward the image forming unit 121, specifically a duct 204 for blowing air toward the charger 111b and a duct 208 for blowing air toward the developer 112b. The inner cover unit 200 is also provided with ducts for blowing air toward the image forming unit 122, specifically a duct 205 for blowing air toward the charger 111c and a duct 209 for blowing air toward the developer 112c. The inner cover unit 200 is also provided with ducts for blowing air toward the image forming unit 123, specifically a duct 206 for blowing air toward the charger 111d and a duct 210 for blowing air toward the developer 112d. In this embodiment, duct 203 is an example of a first duct that guides air drawn in from outside the image forming apparatus 100 via the intake port 171a to the image forming unit 120. Duct 206 is an example of a second duct that guides air drawn in from outside the image forming apparatus 100 via the intake port 172a to the image forming unit 123.

[0048] Here, ducts 203, 204, and 207-210 receive air drawn in from the intake port 171a via the left-side ventilation unit 124. Duct 203 is provided with an inlet 203a that connects to duct 175a of the side duct 175 to allow air to flow from duct 175a into duct 203, and an outlet 203b that allows air from duct 203 to flow out to the charging duct intake port 501a of the charger 111a. In this embodiment, duct 175 is an example of a first main duct, and primary charging duct 501 is an example of a second main duct. Furthermore, the inlet 203a is an example of a first connection part that connects to duct 175a, and the outlet 203b is an example of a second connection part that connects to primary charging duct 501. Also, the intake port 501a of the first charging duct 501 is an example of a third connection part that connects to the outlet 203b.

[0049] Furthermore, the duct 204 has an inlet 204a that connects to the duct 175c of the side duct 175 to allow air to flow from the duct 175c into the duct 204, and an outlet 204b that allows the air inside the duct 204 to flow out to the primary charging duct intake of the charger 111b.

[0050] Furthermore, duct 207 has an inlet 207a that connects to duct 175b of side duct 175 and allows air to flow from duct 175b into duct 207, and an outlet 207b that allows the air inside duct 207 to flow out to the cooling duct 504 of the developer unit 112a. Furthermore, duct 208 has an inlet 208a that connects to duct 175d of side duct 175 and allows air to flow from duct 175d into duct 208, and an outlet 208b that allows the air inside duct 208 to flow out to the intake port of the cooling duct 504 of the developer unit 112b. Furthermore, duct 209 has an inlet 209a connected to duct 175e of side duct 175 for air to flow from duct 175e into duct 209, and an outlet 209b for the air in duct 209 to flow out to the intake port of the cooling duct 504 of the developer unit 112c. Similarly, duct 210 has an inlet 210a connected to duct 175f of side duct 175 for air to flow from duct 175f into duct 210, and an outlet 210b for the air in duct 210 to flow out to the intake port of the cooling duct 504 of the developer unit 112d. In this embodiment, duct 203 is an example of a first duct that guides air drawn in from the intake port 171a to the charging unit 111a of the image forming unit 120. Furthermore, duct 207 is an example of a third duct that guides the air drawn in from the intake port 171a to the developing unit 112a of the image forming unit 120.

[0051] Meanwhile, ducts 205 and 206 receive air drawn in from the intake port 172a via the right-side ventilation unit 126. Duct 205 is provided with an inlet 205a connected to duct 178b of the through duct 178 to allow air to flow from duct 178b into duct 205, and an outlet 205b that allows the air inside duct 205 to flow out to the primary charging duct intake port of the charger 111c. Duct 206 is provided with an inlet 206a connected to duct 178a of the through duct 178 to allow air to flow from duct 178a into duct 206, and an outlet 206b that allows the air inside duct 206 to flow out to the primary charging duct intake port of the charger 111d. In this embodiment, the duct 207 is an example of a first duct that guides the air drawn in from the intake port 171a to the developing unit 112a of the image forming unit 120.

[0052] In this way, the multiple ducts 203 to 210 provided in the inner cover unit 200 are each connected to the side duct 175 or the through duct 178, making it possible to draw in air from outside the image forming apparatus 100. The multiple ducts 203 to 210 provided in the inner cover unit 200 then allow air to be drawn in to the respective developing units and charging units of the image forming units 120 to 123.

[0053] In this embodiment, the inner cover unit 200 is made of resin, and the multiple ducts 203 to 210 are also made of resin. In the above description, a configuration in which the inner cover unit 200 has eight ducts has been shown, but the number and shape are not limited to this. For example, if an image forming unit that forms an image using toner of other colors such as gold or silver is further provided, a duct for that image forming unit may be provided. Also, although a configuration in which a blower fan is provided for each of the multiple ducts 203 to 210 has been shown, a configuration in which one fan draws in air to be blown to the multiple ducts is also possible.

[0054] In this way, by providing the inner cover unit 200 with a duct for blowing air to the image forming units 120-123, the blower fan can be positioned on the outside in the width direction of the housing 101a relative to the image forming units 120-123. Therefore, as described above, it is possible to suppress noise caused by positioning the blower fan on the front side of the image forming apparatus 100, and to prevent the image forming apparatus 100 from becoming larger in the front-to-back direction.

[0055] As described above, the inner cover unit 200 of this embodiment covers multiple image forming units 120 to 123 and is equipped with multiple ducts for blowing air to the multiple image forming units 120 to 123. Therefore, the inner cover unit 200 is larger in size than the image forming unit alone. In this configuration, if any of the components included in the image forming units 120 to 123 require maintenance, the large inner cover unit 200 must be removed each time. Thus, the task of removing the large inner cover unit 200 each time places a heavy burden on maintenance work and reduces work efficiency.

[0056] Therefore, as shown in Figures 6 and 7, the inner cover unit 200 in this embodiment is provided with openings 303a to 303d that allow at least one of the parts of the image forming units 120 to 123 to be inserted and removed individually. Small covers 304a to 304d that cover these openings 303a to 303d are detachably attached to the inner cover unit 200.

[0057] This allows maintenance on the image forming units 120-123 to be performed without removing the inner cover unit 200 by opening the small covers 304a-304d.

[0058] In this embodiment, maintenance of the image forming units 120-123 involves replacing the chargers 111a-111d. The chargers 111a-111d have a shorter lifespan compared to other components of the image forming units 120-123, such as the photoreceptors 105a-105d and the developers 112a-d. Therefore, their replacement frequency is higher compared to other components.

[0059] Therefore, by removing the small cover 304a, it is possible to insert and remove the charger 111a of the image forming unit 120 through the opening 303a. Similarly, by removing the small cover 304b, it is possible to insert and remove the charger 111b of the image forming unit 121 through the opening 303b. Furthermore, by removing the small cover 304c, it is possible to insert and remove the charger 111c of the image forming unit 122 through the opening 303c. Additionally, by removing the small cover 304d, it is possible to insert and remove the charger 111d of the image forming unit 123 through the opening 303d. In this embodiment, the small cover 304a is an example of a third cover that covers the opening 303a and is detachable from the inner cover unit 200. The small cover 304d is an example of a fourth cover that covers the opening 303d and is detachable from the inner cover unit 200.

[0060] In Figure 6, the small cover 304a is shown closed for the image forming unit 120, and the small cover 304b is shown slightly open relative to the opening 303b for the image forming unit 121. The small cover 304c is shown removed from the image forming unit 122, exposing the charger 111c through the opening 304c. The charger 111d is shown being removed from the opening 304c for the image forming unit 123.

[0061] Thus, in this embodiment, it is possible to insert, remove, and replace the chargers 111a to 111d, which are maintenance parts for the image forming units 120 to 123, without removing the inner cover unit 200.

[0062] This eliminates the need to remove and reattach the inner cover, which covers multiple image forming units 120-123 and is equipped with ducts, each time maintenance is performed, thereby improving the workability when maintaining the maintenance parts of the image forming units 120-123.

[0063] Next, the procedure for removing chargers 111a to 111d will be explained using Figures 8 and 9. Since the removal procedure for chargers 111a to 111d is the same, charger 111a will be used as an example. Figures 8 and 9 are cross-sectional views taken along line A-A in Figure 7.

[0064] To remove the charger 111a from the image forming apparatus 100, first press down on the claw portion 305a provided on the small cover 304a with your fingers in the downward direction (-Z direction) as shown in Figure 8(a) to release the engagement with the inner cover unit 200 as shown in Figure 8(b). Then, rotate the small cover 304a around its lower end portion 306a in the direction of arrow F shown in Figure 8(b), thereby making it possible to remove the small cover 304a from the inner cover unit 200. In this embodiment, the small cover 303a is configured to be detachable from the inner cover unit 200, but the small cover 303a may also be configured to be rotatable between an open state that exposes the opening 304a to the inner cover unit 200 and a closed state that seals it.

[0065] Next, as shown in Figure 9(a), the plate spring 301a provided on the front frame 300 of the first housing 101a is elastically deformed upward (+Z direction) in the figure, thereby making the charger 111a pullable out from the housing 101a. Then, as shown in Figure 9(b), fingers are inserted into the handle portion 111aa of the charger 111a, and the charger 111a is pulled out to the right (-Y direction) in the figure. In this way, the charger 111a can be removed from the first housing 101a of the image forming apparatus 100 without removing the inner cover unit 200. Therefore, since it is not necessary to attach and detach the inner cover that covers multiple image forming units 120 to 123 and has ducts each time maintenance is performed, the workability when maintaining the maintenance parts of the image forming units 120 to 123 can be improved.

[0066] Furthermore, in this embodiment, as shown in Figures 7 to 9, the inner cover unit 200 is provided with ducts 203 to 210 in a region different from the region where the openings 303a to 303d are provided. In other words, the openings 303a to 303d are provided in a region different from the ducts 203 to 210.

[0067] This configuration improves the ease of maintenance when servicing the maintenance parts of the image forming units 120 to 123, even when the inner cover unit 200 is equipped with multiple ducts.

[0068] In this embodiment, the chargers 111a to 111d are shown as maintenance parts for the image forming units 120 to 123, but other parts may be inserted and removed through openings 203a to 203d when performing maintenance. For example, a dustproof glass (not shown) provided in the laser scanner unit 107a may be made removable through openings 203a to 203d. This makes it easier to remove foreign matter adhering to the surface of the dustproof glass, which has a higher maintenance frequency than other parts, and to replace the dustproof glass.

[0069] Furthermore, maintenance of the image forming units 120 to 123 may also relate to other components, and the inner cover unit 200 may be configured to have an opening that allows the image forming units 120 to 123 themselves to be inserted and removed. Also, if the maintenance frequency differs for each of the image forming units 120 to 123, the configuration may be such that an opening and a small cover are provided only in a position corresponding to the image forming unit with the highest maintenance frequency.

[0070] However, as in the embodiment described above, by providing openings at positions corresponding to frequently replaced parts, the area of ​​the openings in the inner cover unit 200 can be reduced. Therefore, the area of ​​the region forming the duct in the inner cover unit 200 can be increased. As a result, even in an image forming apparatus for commercial printing that requires a large amount of air to be blown to each of the image forming units 120 to 123, sufficient airflow can be ensured. [Explanation of Symbols]

[0071] 100 Image forming apparatus 105a~105d Photoreceptor 111a~111d Charger 112a~112d Developer 120-123 Image forming unit 200 Inner cover unit 203-210 duct 303a~303d opening 304a~304d Small cover

Claims

1. An image forming apparatus for forming an image on a sheet, One of a plurality of image forming units, the first image forming unit having a first photoreceptor, a first charging unit for charging the first photoreceptor, and a first developing unit for developing the electrostatic latent image formed on the first photoreceptor using toner, One of the plurality of image forming units, the second image forming unit having a second photoreceptor, a second charging unit for charging the second photoreceptor, and a second developing unit for developing the electrostatic latent image formed on the second photoreceptor using toner, A first cover, which is openable and closable, forms part of the exterior of the image forming apparatus. A second cover is provided between the first cover and the plurality of image forming units in the rotational axis direction of the first photoreceptor, and covers the plurality of image forming units. An air intake having a first air intake and a second air intake, A first duct is provided in the second cover and guides air drawn in from outside the image forming apparatus via the first air intake to the first image forming unit, A first fan provided outside the plurality of image forming units in the arrangement direction of the plurality of image forming units, the first fan draws in air to be supplied to the first duct via the first air intake, A second duct is provided in the second cover and guides air drawn in from outside the image forming apparatus via the second air intake to the second image forming unit, A second fan provided on the opposite side of the first fan from the plurality of image forming units in the arrangement direction of the plurality of image forming units, the second fan draws in air to be supplied to the second duct via the second air intake, The system comprises a third cover detachably provided to the second cover so as to cover an opening in the second cover from which at least a portion of the first image forming unit can be inserted and removed, An image forming apparatus characterized by the following features.

2. The system further includes a fan that draws in air to be supplied to the first duct via the aforementioned air intake port. The image forming apparatus according to feature 1.

3. The first duct guides the air drawn in from the intake port to the first charging unit of the first image forming unit. The image forming apparatus according to feature 1 or 2.

4. The first duct guides the air drawn in from the intake port to the first developing unit of the first image forming unit. The image forming apparatus according to feature 1 or 2.

5. The first image forming unit further includes a third duct that guides the air drawn in from the intake port to the first charging unit of the first image forming unit. The image forming apparatus according to feature 4.

6. The first charging unit is removable from the image forming apparatus through the opening. The image forming apparatus according to any one of claims 1 to 5.

7. The exposure apparatus further comprises a glass member and forms an electrostatic latent image on the first photoreceptor by irradiating it with laser light through the glass member. The glass member is insertable into and remove from the image forming apparatus through the opening. The image forming apparatus according to any one of claims 1 to 6.

8. The second cover further comprises a fourth cover detachably provided to the second cover so as to cover another opening in the second cover from which at least a portion of the second image forming unit can be inserted and removed. The image forming apparatus according to any one of claims 1 to 7.

9. A first main duct that guides the air drawn in through the intake port to the first duct, The system further comprises a second main duct that guides the air exhausted from the first duct to the first charging unit, The first duct has a first connecting portion that connects to the first main duct and a second connecting portion that connects to the second main duct. The second main duct has a third connecting portion that connects to the second connecting portion, The third connecting portion is provided in a position that does not overlap with the opening in the direction of the rotation axis of the first photoreceptor. The image forming apparatus according to any one of claims 1 to 8.

10. The first charging unit charges the first photoreceptor by corona discharge, The second charging unit charges the second photoreceptor by corona discharge. The image forming apparatus according to any one of claims 1 to 9.

Images