Image forming apparatus

Abstract

To provide an image forming device capable of eliminating electrostatic damage to fans by solving a problem that, if a duct part of a duct unit rubs against the frame during assembly work and electrostatic charging occurs, the fan is also charged due to inductive charging, and electrostatic damage may occur due to discharge when connecting the fan connector.SOLUTION: A duct unit with a fan is provided with ribs to serve as a guide during assembly to thereby suppress fan charging due to sliding friction during assembly and reduce the sliding area to prevent electrostatic damage.SELECTED DRAWING: Figure 8

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 peripheral.

Background Art

[0002] Conventionally, an image forming apparatus includes a duct unit having a fan and a duct for the purpose of suppressing a temperature rise inside the apparatus and exhausting heat. Such a duct unit needs to remove the charged electric charge during the installation work so as not to cause destruction of the fan due to static electricity during assembly or maintenance, and to prevent the influence of static electricity on the fan.

[0003] In Patent Document 1, when a charged operator is about to inadvertently touch an electrode, the operator approaches a metal support plate first, and the discharge to the support plate eliminates the charge of the operator so as not to affect the electrical components connected to the electrode.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The configuration of Patent Document 1 is effective when the operator himself / herself is charged. However, when the duct portion of the fan duct using an insulating material is charged, static electricity cannot escape even if it is brought close to the support plate, so the charged static electricity is not removed. Further, when the duct portion is charged, the fan itself is also charged due to induced charging, so there is a risk that discharge may occur when connecting the connector of the fan, leading to electrostatic breakdown.

[0006] Therefore, an object of the present invention is to suppress charging during the assembly and maintenance of a duct unit having a fan. [Means for solving the problem]

[0007] An image forming apparatus according to one embodiment of the present invention is an image forming apparatus for forming an image on a recording material, comprising a support frame, a fan, and a duct for guiding air drawn in by the fan, and a duct unit mounted on the support frame, wherein the support frame has a portion facing the duct when the duct unit is mounted, and the duct unit has ribs extending in the direction in which the duct unit is mounted on the support frame and protruding from the outer surface of the duct Furthermore, the duct unit includes, in the direction of the fan's rotation axis, another fan provided on the side opposite to the side on which the fan and the duct are provided, and another duct provided on the opposite side for guiding the air drawn in by the other fan. It is characterized by doing so. [Effects of the Invention]

[0008] This can suppress static electricity during the assembly and maintenance of duct units that have fans. [Brief explanation of the drawing]

[0009] [Figure 1] Schematic diagram of an image forming apparatus [Figure 2] External perspective view of the entire housing of the image forming apparatus. [Figure 3] (a) Perspective view of the vicinity of the duct unit. (b) Perspective view of the right side of the duct unit. (b) Perspective view of the left side of the duct unit. [Figure 4] Cross-sectional view of the duct unit [Figure 5] Right-side view of the duct unit [Figure 6] Left side view of the duct unit [Figure 7] Top view of the duct unit [Figure 8] Perspective view showing the assembly method of the duct unit. [Figure 9] Diagram showing the electrostatic effect of a fan [Figure 10] Perspective view showing the assembly method of the duct unit according to the second embodiment. [Modes for carrying out the invention]

[0010] <First Embodiment> 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.

[0011] [Image Forming System] 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.

[0012] The housing 101 of the image forming apparatus consists of a first housing 101a and a second housing 101b. The first housing 101a is equipped with an image forming section 102, an intermediate transfer belt 106 (described later), a storage compartment 113, and the like.

[0013] Meanwhile, the second housing 101b is equipped with the first fuser 150, the second fuser 160, the reversing transport path 135, and the like, which will be described later.

[0014] The image forming unit 102 includes image forming units 120, 121, 122, and 123 that form toner images of yellow, magenta, cyan, and black, and an intermediate transfer belt 106. In each image forming unit 120 to 123, a primary charger 111 charges the surface of a photosensitive drum 105, which is a drum-shaped photoreceptor. The laser scanner unit 107 performs exposure processing on the photosensitive drum 105 based on command signals generated based on image data and transmitted to the laser scanner unit 107. The laser scanner unit 107 has a laser driver that drives the laser light emitted from a semiconductor laser (not shown) on and off, and guides the laser light from the semiconductor laser to the photosensitive drum 105 via a reflective mirror 109 while distributing it in the main scanning direction using a rotating polyface mirror. As a result, an electrostatic latent image corresponding to the image data is formed on the surface of the photosensitive drum 105.

[0015] The developing device 112 houses a developer containing toner inside and supplies charged toner particles to the photosensitive drum 105. As the toner particles adhere to the drum surface according to the surface potential distribution, the electrostatic latent image carried on the photosensitive drum 105 is visualized as a toner image. The toner image carried on the photosensitive drum 105 is transferred (primary transfer) to the intermediate transfer belt 106 to which a voltage of the opposite polarity to the normal charging polarity of the toner is applied. When forming a color image, the toner images formed by the four image forming units 120 to 123 are multi-transferred so as to overlap each other on the intermediate transfer belt 106, and a full-color toner image is formed on the belt.

[0016] On the other hand, the feeding mechanism feeds the recording material 1 one by one from the storage 113 that is inserted into the housing 101 of the image forming apparatus 100 so as to be pullable, toward the transfer roller 114. The toner image carried on the intermediate transfer belt 106, which is an intermediate transfer body, is transferred (secondary transfer) to the recording material 1 by the transfer roller 114.

[0017] Around the intermediate transfer belt 106, an image formation start position detection sensor 115 for determining the print start position when performing image formation, a feeding timing sensor 116 for timing the feeding of the recording material 1, and a density sensor 117 are arranged. The density sensor 117 measures the density of the patch image carried on the intermediate transfer belt 106. The printer controller adjusts the operating conditions of the image forming unit 102 (for example, the charging target potential of the primary charger 111 and the setting of the bias voltage of the developing device 112) based on the detection result of the density sensor 117.

[0018] 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 recording material 1, a pressure belt 152 for pressing the recording material 1 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 recording material 1 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 recording material 1.

[0019] The second fuser 160 is positioned downstream of the first fuser 150 in the transport path of the recording material 1. 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 recording material 1. 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 recording material 1 while transporting it, and a second post-fixing sensor 163 that detects the completion of the fixing process by the second fuser 160.

[0020] In addition, depending on the type of recording material 1, it may not be necessary to pass it through the second fuser 160. In such cases, the image forming apparatus 100 has a bypass transport path 130 for discharging the recording material 1 without passing through the second fuser 160 in order to reduce energy consumption. The recording material 1 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.

[0021] The recording material 1 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 recording material 1 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.

[0022] In the case of double-sided printing, the recording material 1 with an image formed on the first side is reversed by the reversal unit 136 and transported again towards the transfer roller 114 via the re-transport path 138 to form an image on the second side. The recording material 1 with image formation completed for single-sided printing or with image formation completed for the second side in double-sided printing is discharged to the outside of the image forming apparatus 100 by the discharge roller 139a (discharge unit) 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 recording material 1 that has been switched back by the reversal unit 136 towards the discharge transport path 139, and is configured to allow selection of the front and back sides of the recording material 1 when it is discharged from the image forming apparatus. An image reading device 200 that reads image information from the original is installed on top of the image forming apparatus 100. The sheet discharged by the discharge roller 139a is sent to the finisher 600 and loaded as a finished product into the tray of the finisher 600.

[0023] [Airflow configuration] Figure 2 is an external view of the first housing 101a of the image forming apparatus of the present invention. As shown in Figure 2, the front of the first housing 101a is provided with a left front door 170a and a right front door 170b, which are exterior covers that constitute part of the external appearance of the image forming apparatus 100. These doors are designed to open and close like double doors, with the left door approximately in the center of the left-right direction as the dividing line. Above the left front door 170a, a cover duct 171 is provided, which has an air intake port 171a on a part of its lower surface. Figure 3 shows an external perspective view of the duct unit. (a) shows an external perspective view of the right side of the duct unit, and (b) shows an external perspective view of the left side of the duct unit.

[0024] As shown in Figure 3(a), the cover duct 171 is a duct having three air intake ports 171a and filters 172 provided at each air intake port. The cover duct 171 is connected to the duct unit 174 shown in Figure 3. The duct unit 174 is fixed to the support frame 190 of the housing 101a. Here, the support frame 190 is a frame that supports the units inside the housing 101a, such as the image forming units 120 to 123 mentioned above. The support frame 190 is composed of a bottom plate (not shown), multiple support columns such as the left front support column 190d and the left rear support column 190e erected from the bottom plate, the main body front upper beam 190a and the main body left upper beam 190b supported by the support columns, and stays connecting each of the support columns.

[0025] The duct unit 174 is fixed to the front upper beam 190a and the cover support member 190c connected to the left upper beam 190b of the support frame 190. In this embodiment, the duct unit 174 is directly fixed to the front upper beam 190a of the support frame 190, and indirectly fixed to the left upper beam 190b of the support frame 190 via the cover support member 190c.

[0026] The duct unit 174 has fans 180a to 180f. Fans 180a to 180f are connected to the duct unit 174 so that their intake sides are attached. Fans 180a to 180f are, for example, sirocco fans, and fans 180a, 180b, and 180c are provided on one side of the duct unit 174, while fans 180d, 180e, and 180f are mounted on the opposite side, facing each other. In this embodiment, the duct portion of the duct unit 174 is formed from a resin material.

[0027] When arranging multiple fans 180, the fan placement was examined using airflow simulation to prevent opposing fans 180 from being affected by each other's intake airflow. As shown in Figure 4, in this embodiment, fans 180a to 180f, which are located opposite each other via the internal duct unit 174, are positioned so as not to overlap with the intake airflow direction (direction of the fan's rotation axis) to suppress airflow deviation. Alternatively, a configuration may be used in which four fans 180a to 180d are arranged on one side, and two fans 180e and 180f are arranged on the opposite side.

[0028] Generally, it is possible to prevent airflow deviation by not placing obstacles such as walls within 20 mm of the fan's intake. Therefore, the width of the duct unit 174 in the X-axis direction is set to 40 mm, taking into consideration the influence of intake between the opposing fans 180.

[0029] In the duct unit 174, air drawn in by fans 180a to c is guided further downstream by duct section 174b, and air drawn in by fans 180d to f is guided further downstream by duct section 174a.

[0030] Furthermore, the exhaust ports of duct sections 174a and 174b are connected to a joint duct 175 that extends to the front side (+Y side) of the main unit. Also, as shown in Figures 5 and 6, the airflow inside duct sections 174a and 174b and the joint duct 175 is partitioned for each fan 180a to f.

[0031] The joint duct 175 is supported by the duct unit 174 and the front upper beam 190a of the main body. In the airflow of the joint duct 175, the upstream side is connected to the duct unit 174, and the downstream side is connected to the inner cover duct 173 (Figure 7) for each path of fans 180a to 180f. As shown in Figure 7, the opening of the inner cover duct 173 opposite the joint duct 175 is connected to each image forming unit 120, 121, 123, and 124.

[0032] Air drawn into the duct unit 174 via the intake port 171a passes through the inner cover duct 173 and is blown to the charger 111 and developer 112 of the image forming units 120-123. In this embodiment, the airflow blown to the charger 111 functions as an airflow for recovering ozone generated by corona discharge. In this embodiment, the airflow blown to the developer 112 functions as an airflow for cooling the developer 112 itself.

[0033] [Detailed Unit Configuration] When assembling the product or performing maintenance, the duct unit 174 is mounted to the support frame 190 from the top of the housing 101a in the -Z direction (vertical direction), as shown in Figure 8. As described above, the duct unit 174 has fans 180a to 180f, making it a heavier unit compared to a duct unit with only one fan. Therefore, in this embodiment, when assembling the duct unit 174 to the support frame 190, the assembly is done while aligning it with the upper left beam 190b of the main body of the support frame 190, taking into consideration the load on the worker. In this embodiment, the upper left beam 190b is an example of an opposing part that faces the duct section 174a when the duct unit 174 is mounted to the support frame 190.

[0034] In this case, the duct portion of the duct unit 174 may rub against the upper left beam 190b of the main body, potentially causing the duct portion 174a to become electrically charged. When the duct portion 174a becomes electrically charged due to this rubbing, the fans 180e~180f fixed to the duct portion 174a will also become electrically charged due to inductive charging. This increases the risk of electrostatic discharge when connecting the fan connectors, potentially leading to electrostatic discharge damage.

[0035] Therefore, in this embodiment, ribs 181a, 181b, and 181c, with a width of 2.5 mm and a height of 0.6 mm, extending in the +Z direction, are provided on the duct portion 170a, which is located on the +X side facing the upper left beam 190b of the main body of the duct unit 174. In other words, ribs 181a, 181b, and 181c are provided on the duct portion 174a, extending in the direction in which the duct unit 174 is attached to the support frame 190 and protruding from the outer surface of the duct portion 170a.

[0036] These ribs 181a to 181c are provided to reduce the area in which the duct portion 174a rubs against the front upper beam 190a of the main body when assembling the duct unit 174 to the support frame 190. This suppresses the charging of the duct portion 174a of the duct unit 174 when assembling the duct unit 174 to the support frame 190, and thereby suppresses the charging of the fans 180d to 180f caused by the charging of the duct portion 174a.

[0037] Figure 9 is a graph comparing the amount of charge when ribs 181a to 181c are provided on the duct section 174a as in this embodiment, and when ribs 181a to 181c are not provided. In Figure 9, the dashed line shows the amount of charge of fans 180d to f when ribs 181a to 181c are not provided, and the solid line shows the amount of charge of fans 180d to f when ribs 181a to 181c are provided.

[0038] As shown in Figure 9, in the duct unit 174 having ribs 181a to 181c as described in the above embodiment, it has been confirmed that the amount of charge generated in the fans 180e to f during assembly of the duct unit is 20% or less compared to when the ribs are not provided.

[0039] In this embodiment, ribs are not provided on the duct portion 174b, which is not moved along a part of the support frame 190 during assembly. However, if a part of the support frame 190 or other component that may rub against the duct portion 174b is located opposite the duct portion 174b, ribs may be provided on the duct portion 174b as well.

[0040] <Second Embodiment> Next, a duct unit 274 that differs from the first embodiment described above will be explained. The only difference between the duct unit 274 and the first embodiment described above is the mounting direction to the support frame 190 and the position of the ribs. Therefore, the same reference numerals are used for the support frame 190 and its description will be omitted.

[0041] As shown in Figure 10, the duct unit 274 in this embodiment can be assembled to the support frame 190 of the housing 101a in the -Y direction (horizontal direction). Since the duct unit 274 has six fans, similar to the first embodiment, it is a heavier unit than a duct unit with only one fan. Therefore, considering the load on the worker, this embodiment assumes that it will be assembled along the left front support column 190d of the support frame 190. In this embodiment, the left front support column 190d is an example of an opposing part that faces the duct section 274a when the duct unit 274 is mounted on the support frame 190.

[0042] Therefore, in this embodiment, three ribs 281da, 281b, and 281c, each 2.5 mm wide and 0.6 mm high, extending in the +Y direction, are provided on the duct portion 274a, which is located on the +X side of the duct unit 274. In other words, ribs 281da, 281b, and 281c are provided on the duct portion 274a, extending in the direction in which the duct unit 274 is attached to the support frame 190 and protruding from the outer surface of the duct portion 270a.

[0043] This reduces the area over which the ribs 281a to 281c rub against the left front support column 190d when assembling the duct unit 274 to the support frame 190. In this configuration as well, it was confirmed that the amount of charge generated in the fans 280e to 280f when assembling the duct unit 274 was 20% or less compared to when the ribs 281a to 281c were not provided, similar to the first embodiment shown in Figure 9. Therefore, in this embodiment as well, it was possible to suppress the charging of the duct portion 274a of the duct unit 274 when assembling the duct unit 274 to the support frame 190, and to suppress the charging of the fans 280d to 280f caused by the charging of the duct portion 274a.

[0044] <Other Embodiments> In the embodiment described above, a configuration in which a total of three ribs 181a to 181c are provided on the duct portion 174a of the duct unit 174 is shown, but the configuration is not limited to this. For example, a configuration with two or fewer ribs or four or more ribs may also be used. Even with this configuration, it is possible to suppress static electricity due to friction of the duct portion when the duct unit is installed, compared to a configuration in which no ribs are provided on the duct portion. [Explanation of Symbols]

[0045] 100 Image forming apparatus 101a First enclosure 105 Photosensitive drum 111 Charger 112 Developer 120 (121~123) Image forming unit 190 Support frame 174 Duct Unit 174a Duct section 180a~f fan 181a~c Rib

Claims

1. An image forming apparatus for forming an image on a recording material, Support frame and A duct unit is provided, which has a fan and a duct for guiding the air drawn in by the fan, and is mounted on the support frame, The support frame has a portion that faces the duct when the duct unit is mounted, The duct unit extends in the direction in which the duct unit is attached to the support frame, The duct has ribs protruding from its outer surface, The duct unit includes, in the direction of the fan's rotation axis, another fan provided on the side opposite to the side on which the fan and the duct are provided, and another duct provided on the opposite side for guiding the air drawn in by the other fan. An image forming apparatus characterized by the following features.

2. The mounting direction of the duct unit is the vertical direction. The image forming apparatus according to feature 1.

3. The mounting direction of the duct unit is horizontal. The image forming apparatus according to feature 1.

4. The image forming unit further comprises a photoreceptor, a charger for charging the photoreceptor by corona discharge, and a developer for developing the electrostatic latent image formed on the photoreceptor using toner. The duct unit blows the air drawn in by the fan to the image forming unit. The image forming apparatus according to any one of claims 1 to 3.

Images