Image forming apparatus

Abstract

An image forming apparatus includes: a main body frame; a processing unit which can be detached from the main body frame by being pulled out to one side in the first direction; a plurality of main body side contacts protruding in the second direction and arranged at intervals from each other in the first direction; the main body frame has a guide surface extending in a first direction, the processing unit has a roller, the guide surface has an inclined surface inclined from an upstream side to a downstream side in an extraction direction or in any one of an up-down direction, and when the processing unit is extracted, the roller travels on the inclined surface, and when the processing unit is extracted, the roller travels on the inclined surface. The position of the unit-side contact in the vertical direction is displaced to an avoidance position where the unit-side contact does not collide with the main body-side contact located on the downstream side in the extraction direction.

Description

Technical Field

[0001] The present invention relates to an image forming apparatus. Background Art

[0002] A conventional image forming apparatus includes a process unit that is detachably attached to a main body of the apparatus, and includes a developing cartridge and the like for developing a toner image.

[0003] When the processing unit is installed in the device body, it is necessary to electrically connect the processing unit to the device body. Therefore, a main body side contact point is provided on the device body, and a unit side contact point is provided on the processing unit. The processing unit is electrically connected to the device body by contacting the main body side contact point with the unit side contact point.

[0004] A plurality of main body side contacts and unit side contacts are provided respectively. For example, a plurality of main body side contacts (i.e., a plurality of unit side contacts) are arranged in the direction of extraction of the processing unit when the processing unit is removed from the device main body. In such a structure, when the processing unit is removed from the device main body, there is a possibility that the main body side contacts and the unit side contacts collide. If the main body side contacts collide with the unit side contacts, there is a possibility that at least one of the main body side contacts and the unit side contacts fails. Summary of the invention

[0005] To solve the above-mentioned problems, an object of the present invention is to provide an image forming apparatus having a structure in which a process unit is detachable from a main body of the apparatus and the process unit can be safely removed.

[0006] To achieve the above object, an image forming apparatus according to one embodiment of the present invention includes: a main frame having an installation area; a processing unit installed in a detachable manner relative to the installation area, and being detachable from the main frame by being pulled out from a state installed in the installation area to one side of a first direction perpendicular to the vertical direction, the processing unit performing a development process of developing an electrostatic latent image into a toner image; a plurality of main body side contacts arranged on the main frame, protruding toward the installation area and in a second direction perpendicular to the first direction, and spaced apart from each other in the first direction; and a plurality of unit side contacts arranged on the processing unit, respectively assigned to the plurality of main body side contacts, and the unit side contacts contacting the assigned main body side contacts when the processing unit is installed in the installation area. The main frame has a guide surface extending in the first direction. The processing unit has a roller, and the roller travels on the guide surface when the processing unit is installed and removed from the installation area. The guide surface has an inclined surface, and the inclined surface is inclined in either the vertical direction from the upstream side to the downstream side in the pulling direction when the processing unit is pulled out from the installation area. When the process unit is pulled out from the installation area, the rollers run on the inclined surface, and the unit-side contacts are displaced in the vertical direction to avoid colliding with the main body-side contacts located downstream in the pulling direction.

[0007] According to the present invention, in a structure including a processing unit that is attachable to and detachable from the apparatus main body, the processing unit can be safely removed. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a perspective view of the image forming apparatus according to the embodiment. Figure 2 yes Figure 1 A perspective view of the image forming apparatus shown in FIG. 1 with its front cover opened. Figure 3 It is a schematic diagram showing the internal structure of the image forming apparatus according to the embodiment. Figure 4 It is a schematic diagram showing an image forming section of the image forming apparatus according to the embodiment. Figure 5 yes Figure 1 A perspective view of the image forming apparatus shown in FIG. 1 in a state where the process unit is pulled out. Figure 6 It is a perspective view showing a main body side contact of the image forming apparatus according to the embodiment. Figure 7 It is a perspective view showing a high voltage substrate of the image forming apparatus according to the embodiment. Figure 8 It is a perspective view showing a unit-side contact of the image forming apparatus according to the embodiment. Fig. 9 yes Figure 8 An enlarged view of a unit-side contact of the image forming apparatus shown. Fig.10 It is a schematic diagram showing a contact structure between a main body side contact and a unit side contact of the image forming apparatus according to the embodiment. Fig.11 It is a perspective view showing a guide member of the image forming apparatus according to the embodiment. Fig.12 Observed from the second direction Fig.11 A side view of the guide component is shown. Fig.13 This is a perspective view of the lower left portion of the process unit of the image forming apparatus according to the embodiment, as viewed from below. Fig.14 It is a perspective view showing the positional relationship between a guide member and a process unit of the image forming apparatus according to the embodiment. Fig.15 It is a schematic diagram showing a traveling state of rollers on a guide surface of the image forming apparatus according to the embodiment. Fig.16 Schematic diagram showing the positional relationship between the main body side contact points and the unit side contact points of the image forming apparatus according to the embodiment. DETAILED DESCRIPTION

[0009] Below, refer to Figures 1 to 16 , an image forming apparatus 100 according to an embodiment of the present invention is described. In the following description, a tandem color laser printer is used as an example, but the present invention is not limited to printers, and can also be applied to a digital multifunction machine having a copy function.

[0010] In the following description, the direction perpendicular to the flat ground on which the image forming apparatus 100 is installed is referred to as the up-down direction. In addition, one direction in the horizontal directions perpendicular to the up-down direction is denoted by reference numeral D1 and referred to as the first direction D1, and the other direction perpendicular to the one direction is denoted by reference numeral D2 and referred to as the second direction D2. In addition, "horizontal" is not an absolute horizontal direction, but includes a substantially horizontal direction.

[0011] For example, the first direction D1 is the front-to-back direction (depth direction) of the image forming apparatus 100. One side of the first direction D1 is the front side, and the other side opposite to the one side of the first direction D1 is the rear side. In addition, the second direction D2 is the left-to-right direction (width direction) of the image forming apparatus 100. One side of the second direction D2 is the left side, and the other side opposite to the one side of the second direction D2 is the right side.

[0012] <Overall Configuration of Image Forming Apparatus> The image forming apparatus 100 of this embodiment has Figure 1 and Figure 2 The image forming apparatus 100 has a main frame 1. In addition, the image forming apparatus 100 has a front cover CV. The main frame 1 is covered by a sealing cover (other covers are omitted from the figure) including the front cover CV. The main frame 1 supports the sealing cover. The front cover CV is arranged on one side of the first direction D1. The front cover CV covers the internal area of ​​the image forming apparatus 100 from one side of the first direction D1.

[0013] The main frame 1 has an installation area 100A (see FIG. 1 ) for installing a processing unit 2 described later. Figure 6 and Fig.11 ). The internal area of ​​the image forming device 100 becomes the installation area 100A. The main frame 1 supports the front cover CV so that it can rotate around the axis extending in the second direction D2. The front cover CV rotates by swinging its upper end with its lower end as a fulcrum. In other words, the front cover CV is supported to be openable and closable relative to the main frame 1. By opening the front cover CV, the installation area 100A is exposed to one side of the first direction D1 (refer to Figure 2 By closing the front cover CV, the mounting area 100A is covered from one side in the first direction D1 (see Figure 1 ).

[0014] like Figure 3 As shown in FIG. 1 , the image forming apparatus 100 includes a main conveying path MP. Figure 3 The main transport path MP is indicated by a solid arrow in the figure, and the double-sided printing transport path DP described later is indicated by a dotted arrow.

[0015] The image forming apparatus 100 also includes a sheet cassette CA. The sheet cassette CA stores sheets S used for printing. The type of the sheets S is not particularly limited.

[0016] In a print job, the image forming apparatus 100 supplies the sheet S from the sheet cassette CA to the main conveyance path MP and conveys the sheet S along the main conveyance path MP. Then, the image forming apparatus 100 prints an image on the conveyed sheet S. In other words, the image forming apparatus 100 transfers a toner image to the conveyed sheet S.

[0017] The sheet cassette CA is installed below the main body of the image forming apparatus 100. The sheet cassette CA is attachable to and detachable from the main body (in other words, the main frame 1) of the image forming apparatus 100. The sheet cassette CA can be removed from the main body by pulling the sheet cassette CA out from the main body toward one side in the first direction D1.

[0018] The image forming apparatus 100 includes image forming units 110 for four colors, cyan, magenta, yellow, and black. Each image forming unit 110 forms a toner image of a corresponding color. Hereinafter, the configuration of a certain image forming unit 110 will be described. The basic configurations of the image forming units 110 are the same. Therefore, the configuration of the other image forming units 110 will be described by referring to the following description, and thus the description thereof will be omitted.

[0019] like Figure 4 As shown, the image forming unit 110 includes a developing cartridge 200. The developing cartridge 200 contains toner of corresponding colors and performs a developing process using the toner. In addition, the image forming unit 110 includes a photosensitive drum 111 and a charging device 112. In addition, the image forming device 100 includes an exposure unit 113 for the image forming unit 110 of four colors. In addition, the image forming unit 110 includes a cleaning device 114.

[0020] When the image is formed by the image forming unit 110, the photosensitive drum 111 is rotated. The charging device 112 charges the outer peripheral surface of the photosensitive drum 111. The exposure unit 113 exposes the outer peripheral surface of the photosensitive drum 111 to form an electrostatic latent image on the outer peripheral surface of the photosensitive drum 111. In addition, as a development process, the developer cartridge 200 supplies toner to the outer peripheral surface of the photosensitive drum 111 to perform a process of developing the electrostatic latent image into a toner image. In addition, the toner image on the outer peripheral surface of the photosensitive drum 111 is transferred once to the intermediate transfer belt 121 described later. The cleaning device 114 removes the toner that has not been transferred to the intermediate transfer belt 121 and remains on the outer peripheral surface of the photosensitive drum 111.

[0021] return Figure 3 The image forming apparatus 100 includes an intermediate transfer unit 120. The intermediate transfer unit 120 is disposed below each image forming unit 110. The intermediate transfer unit 120 includes an intermediate transfer belt 121. The intermediate transfer belt 121 is an endless belt. The intermediate transfer belt 121 corresponds to an "intermediate transfer body".

[0022] The intermediate transfer belt 121 is stretched and supported rotatably by a plurality of rollers including a driving roller 122 (other rollers are not labeled). The intermediate transfer belt 121 is in contact with the outer peripheral surface of the photosensitive drum 111 and rotates in this state. The driving roller 122 receives power from a belt motor (not shown) and rotates. The intermediate transfer belt 121 rotates as the driving roller 122 rotates.

[0023] The intermediate transfer unit 120 includes a first transfer roller 123. One first transfer roller 123 is allocated to each color of cyan, magenta, yellow, and black. Each first transfer roller 123 is arranged on the inner peripheral side of the intermediate transfer belt 121. Each first transfer roller 123 is arranged opposite to the photosensitive drum 111 of the corresponding color and sandwiches the intermediate transfer belt 121.

[0024] The intermediate transfer unit 120 includes a second transfer roller 124. The second transfer roller 124 is in pressure contact with the outer peripheral surface of the intermediate transfer belt 121, and forms a transfer nip with the intermediate transfer belt 121. The main conveying path MP passes through the transfer nip.

[0025] Each image forming unit 110 forms a toner image of a corresponding color. Furthermore, each first transfer roller 123 transfers the toner image to the outer peripheral surface of the intermediate transfer belt 121. That is, the intermediate transfer belt 121 receives the transfer of the toner image from the processing unit 2 described later. The intermediate transfer belt 121 carries the toner image transferred from each photosensitive drum 111 on the outer peripheral surface and rotates. When the sheet S passes through the transfer slit, the sheet S contacts the outer peripheral surface of the intermediate transfer belt 121. A transfer electric field is formed between the second transfer roller 124 and the intermediate transfer belt 121, and the toner image is secondarily transferred to the sheet S passing through the transfer slit.

[0026] The image forming apparatus 100 includes a fixing roller pair 130. The fixing roller pair 130 includes a heating roller and a pressure roller. The heating roller has a built-in heater. The pressure roller forms a fixing nip with the heating roller by being in pressure contact with the heating roller, and the fixing roller pair 130 rotates while sandwiching a sheet S conveyed from the transfer nip. That is, the fixing roller pair 130 heats and presses the sheet S passing through the fixing nip. In this way, the fixing roller pair 130 fixes the toner image transferred to the sheet S on the sheet S. Then, the sheet S is discharged to the discharge tray ET.

[0027] As a printing job, the image forming apparatus 100 can perform not only a single-sided printing job of printing a toner image on only one side of a sheet S, but also a double-sided printing job of printing a toner image on both sides of a sheet S. To perform the double-sided printing job, the image forming apparatus 100 includes a double-sided printing conveying path DP.

[0028] The duplex printing conveying path DP branches from the main conveying path MP downstream of the fixing slit in the sheet conveying direction, and merges with the main conveying path MP upstream of the transfer slit in the sheet conveying direction.

[0029] When the executed job is a single-sided printing job, the sheet S passes through the transfer slit only once, and the primary transfer process is performed on the sheet S that passes through the transfer slit. After the primary transfer process, the sheet S is directly discharged to the discharge tray ET.

[0030] When the job to be executed is a double-sided printing job, the sheet S passes through the transfer slit twice because the front and back sides of the sheet S are transferred once respectively. Specifically, when the sheet S passes through the transfer slit for the first time, the transfer process is performed on one side of the sheet S. After the first transfer process, after the rear end of the sheet S passes through the fixing slit and before the sheet S is completely discharged to the discharge tray ET, the sheet S is switched back. In this way, the sheet S is introduced into the double-sided printing conveying path DP from its rear end.

[0031] Then, the sheet S is conveyed along the double-sided printing conveying path DP. Furthermore, the sheet S is returned to the main conveying path MP from the upstream side of the transfer slit in the sheet conveying direction. The sheet S returned to the main conveying path MP passes through the transfer slit again. At this time, the direction of the front and back sides of the sheet S is reversed compared to the previous time it passed through the transfer slit. In this way, when the sheet S passes through the transfer slit for the second time, the other side opposite to the one side of the sheet S is subjected to transfer processing.

[0032] <Processing unit configuration> The image forming apparatus 100 includes a processing unit 2 that performs a development process for developing an electrostatic latent image into a toner image. Specifically, the image forming units 110 of four colors (i.e., a plurality of colors) are unitized to form the processing unit 2. In other words, the processing unit 2 includes at least four color (i.e., a plurality of) developing cartridges 200.

[0033] The processing unit 2 has a unit frame 21 (see Figure 5 ). The image forming unit 110 of four colors is arranged on the unit frame 21. That is, the developing cartridges 200 of four colors are arranged on the unit frame 21. By arranging the image forming unit 110 of four colors on the unit frame 21, the image forming unit 110 of four colors is unitized.

[0034] The image forming units 110 of four colors are arranged in the first direction D1. That is, the developing cartridges 200 of four colors are arranged in the first direction D1. Here, the unit frame 21 has at least a pair of side plates (reference numerals omitted) that clamp the image forming units 110 of four colors in the second direction D2. The pair of side plates of the unit frame 21 rotatably supports each rotating body included in the image forming units 110 of four colors.

[0035] The unit frame 21 is installed relative to the main frame 1 in a manner that it can be attached and detached in the horizontal direction (specifically, the first direction D1). In this way, the processing unit 2 can be attached and detached relative to the device body (i.e., the main frame 1) of the image forming apparatus 100 in the horizontal direction. When the image forming apparatus 100 is maintained, the processing unit 2 is removed from the device body. For example, when a certain developing cartridge 200 is replaced, the processing unit 2 is removed from the device body.

[0036] In the removal operation of the processing unit 2, first, the front cover CV is opened in a state where the processing unit 2 is installed in the apparatus body of the image forming apparatus 100 (that is, the unit frame 21 is installed in the main frame 1). Figure 2 The processing unit 2 is in the state shown. That is, the processing unit 2 is exposed to one side in the first direction D1. And, from this state, the unit frame 21 is pulled out to one side in the first direction D1. The processing unit 2 is removed from the main frame 1 by being pulled out to one side in the first direction D1 from the state installed in the installation area 100A.

[0037] For example, the unit frame 21 has a grip portion 2 a that is gripped by a worker who removes the processing unit 2 . Figure 5 The processing unit 2 is shown in a state where it is pulled out to one side in the first direction D1 relative to the main frame 1 .

[0038] By pulling out the processing unit 2 from the main frame 1, the four-color developer cartridges 200 are exposed upward. The four-color developer cartridges 200 are installed relative to the unit frame 21 in a manner that they can be independently loaded and unloaded. Under this structure, even if a certain developer cartridge 200 is removed from the unit frame 21, the other developer cartridges 200 are still installed on the unit frame 21. That is, in order to remove all the four-color developer cartridges 200 from the unit frame 21, it is necessary to remove the four-color developer cartridges 200 separately. Regarding the structural elements different from the developer cartridge 200, such as the photosensitive drum 111 in the image forming unit 110, they are all fixedly mounted on the unit frame 21 and cannot be removed from the unit frame 21.

[0039] The four color developing cartridges 200 are vertically attachable and detachable to the unit frame 21. When removed from the unit frame 21, the four color developing cartridges 200 are lifted up relative to the unit frame 21. Therefore, the unit frame 21 does not cover the four color developing cartridges 200 from above.

[0040] <Contact structure of the device body and processing unit> The image forming apparatus 100 has Figure 6 to Figure 10 Thus, when the processing unit 2 is mounted on the main frame 1, the apparatus body of the image forming apparatus 100 and the processing unit 2 are electrically connected.

[0041] Specific as Figure 6 and Figure 7 As shown, the image forming apparatus 100 includes a main body side contact 10. The main body side contact 10 is connected to a high voltage substrate 100B. The high voltage substrate 100B is arranged on the main body frame 1. In this way, the main body side contact 10 is arranged on the main body frame 1. In addition, Figure 6 This is a perspective view of the installation area 100A as viewed from the left front of the image forming apparatus 100 .

[0042] The high voltage substrate 100B is arranged on the right side of the main frame 1. The main body side contact 10 protrudes from the right side of the main frame 1 to the mounting area 100A. In other words, the main body side contact 10 protrudes in the second direction D2. In other words, at least a part of the main body side contact 10 is arranged in the mounting area 100A. In this way, the main body side contact 10 can contact the processing unit 2 arranged in the mounting area 100A.

[0043] In addition, if Figure 8 and Fig. 9As shown, the image forming apparatus 100 includes a unit side contact 20. The unit side contact 20 is disposed on the process unit 2. In other words, the process unit 2 includes the unit side contact 20. The unit side contact 20 is supported by a unit frame 21. The unit side contact 20 is exposed from a through hole 21a formed on the unit frame 21. The unit side contact 20 is connected to the components of the process unit 2 (such as the photosensitive drum 111 and the developing cartridge 200).

[0044] The number of the main body side contacts 10 is plural. The number of the main body side contacts 10 is 10. The plurality of main body side contacts 10 are spaced apart from each other in the first direction D1. The plurality of main body side contacts 10 are classified into an upper column and a lower column. The upper column includes 4 main body side contacts 10, and the lower column includes 6 main body side contacts 10.

[0045] The number of the unit-side contacts 20 is the same as the number of the main body-side contacts 10 (i.e., multiple). One unit-side contact 20 is allocated to each of the multiple main body-side contacts 10. If the number of the main body-side contacts 10 is 10, the number of the unit-side contacts 20 is 10. When the processing unit 2 is mounted in the mounting area 100A, the multiple unit-side contacts 20 are respectively in contact with the allocated main body-side contacts 10 among the multiple main body-side contacts 10. In this way, the processing unit 2 is electrically connected to the high-voltage substrate 100B.

[0046] Hereinafter, a detailed description will be given with focus on one of the main body side contacts 10. Here, the plurality of main body side contacts 10 are made of the same material and have the same shape. Therefore, the following description will be referred to for the other main body side contacts 10, and their detailed description will be omitted.

[0047] The main body side contact 10 is a helical torsion spring (see Fig.10 ). That is, the main body side contact 10 has a coil spring portion (reference numerals omitted), and a pair of arm portions 10a and 10b extending from both ends of the coil spring portion in a tangential direction. The helical torsion spring as the main body side contact 10 has an axial direction in the up-down direction. In the helical torsion spring as the main body side contact 10, one arm portion 10a protrudes toward the mounting area 100A and can contact the processing unit 2 mounted in the mounting area 100A. In the helical torsion spring as the main body side contact 10, the other arm portion 10b is fixed and connected to the high voltage substrate 100B.

[0048] The main body side contact 10 applies a force to the process unit 2 in the second direction D2 (specifically, from the right side to the left side). When the process unit 2 is mounted in the mounting area 100A, the main body side contact 10 generates a pressing force on the process unit 2.

[0049] Specifically, by installing the processing unit 2 in the installation area 100A, Fig.10 The state change of the above figure is Fig.10In addition, Fig.10 The state in the above figure is the state before the processing unit 2 is installed in the installation area 100A. Fig.10 The state of the lower figure is a state in which the processing unit 2 is installed in the installation area 100A.

[0050] exist Fig.10 In the state of the above figure, the unit side contact 20 and the main body side contact 10 are not in contact. Fig.10 In the state shown in the figure above, the processing unit 2 is pushed further into the installation area 100A, and the unit side contact 20 contacts the main body side contact 10. At this time, the arm 10a of the main body side contact 10 is pressed in the torsion direction of the spiral torsion spring by the unit side contact 20. Moreover, the processing unit 2 is pushed further into the installation area 100A. In this way, Fig.10 The status of the figure below.

[0051] Fig.10 The arrow Db in FIG. 1 represents the push direction of the processing unit 2 when the processing unit 2 is installed in the installation area 100A. Fig.10 The arrow Da in FIG. 1 represents the direction in which the process unit 2 installed in the installation area 100A is removed from the main frame 1. Figure 12 to Figure 16 The same is true. The extraction direction Da of the processing unit 2 corresponds to a direction toward one side of the first direction D1, and the insertion direction Db of the processing unit 2 corresponds to a direction toward the other side opposite to the one side of the first direction D1.

[0052] <Installation and removal guidance of processing unit> Main frame 1 Fig.11 and Fig.12 The guide member 12 has a guide surface 11 extending in the first direction D1. The guide surface 11 is formed on the guide member 12. The upper surface of the guide member 12 is the guide surface 11. As will be described in detail later, the upper surface of the guide member 12 (ie, the guide surface 11) is not flat.

[0053] In the installation area 100A, guide members 12 are arranged on one side and the other side in the second direction D2. Specifically, the guide members 12 are arranged at the lower right and lower left of the installation area 100A. The guide surfaces 11 of the guide members 12 have the same shape. Fig.11 The guide member 12 disposed at the lower right side of the mounting area 100A is not shown.

[0054] like Fig.13As shown, the processing unit 2 has a roller 22, and the roller 22 can rotate around an axis extending in the second direction D2. The roller 22 is supported by the unit frame 21 so as to be rotatable. The rollers 22 are respectively arranged on the right side plate and the left side plate of the unit frame 21. The roller 22 is arranged at the end of the other side (i.e., the rear side) of the first direction D1 in the unit frame 21. In other words, the roller 22 is arranged at the end of the upstream side in the extraction direction of the processing unit 2 when the processing unit 2 is removed from the main frame 1. Fig.13 The roller 22 disposed on the right side plate of the unit frame 21 is not shown.

[0055] When the processing unit 2 is mounted or removed from the installation area 100A, the roller 22 moves on the guide surface 11. When the processing unit 2 is mounted or removed from the installation area 100A, the gripping portion 2a of the unit frame 21 is slightly lifted so that only the roller 22 contacts the guide surface 11. In this state, when the processing unit 2 is pushed in or pulled out, the roller 22 rotates and the processing unit 2 moves in the first direction D1. In this way, the mounting and removal of the processing unit 2 becomes easy.

[0056] Fig.14 FIG. 2 shows the positional relationship between the guide surface 11 and the roller 22 when the processing unit 2 is installed in the installation area 100A. Fig.14 Although not shown in the figure, the processing unit 2 is positioned relative to the main frame 1 by the engagement of the unit side positioning portion provided on the processing unit 2 with the main body side positioning portion provided on the main frame 1. For example, the unit side positioning portion is a protrusion protruding in the second direction D2. The main body side positioning portion is a long hole penetrating in the second direction D2 and having the first direction D1 as the long side direction. By the engagement of the protrusion with the long hole (in other words, the protrusion is inserted into the long hole), the movement (position deviation) of the processing unit 2 in the up and down direction is restricted.

[0057] By pushing the processing unit 2 into the installation area 100A to a certain extent, the unit side positioning portion engages with the main body side positioning portion. As a result, the roller 22 is no longer in contact with the guide surface 11. In the state where the unit side positioning portion engages with the main body side positioning portion, even if the processing unit 2 is pushed in or pulled out, the processing unit 2 moves in the first direction D1 in a state where the position in the up-down direction is not displaced. That is, in the state where the unit side positioning portion engages with the main body side positioning portion, the main frame 1 supports the processing unit 2 in a state where the position of the unit side contact 20 in the up-down direction is not displaced. When the processing unit 2 is pushed in to the end, the processing unit 2 is installed in the installation area 100A. In this way, it becomes Fig.14 Status shown.

[0058] On the other hand, when the process unit 2 is pulled out from the installation area 100A, until the engagement between the main body side positioning portion and the unit side positioning portion is released, the process unit 2 moves in the first direction D1 without displacing the position of the unit side contact 20 in the vertical direction. That is, the main body frame 1 supports the process unit 2 without displacing the position of the unit side contact 20 in the vertical direction.

[0059] Here, the main body side contact 10 is a helical torsion spring whose axial direction is the vertical direction, and one arm portion 10a thereof is in contact with the unit side contact 20. When such a main body side contact 10 is used, if the position of the unit side contact 20 in the vertical direction is displaced while the main body side contact 10 and the unit side contact 20 are in contact, the arm portion 10a of the main body side contact 10 is stretched in the vertical direction, and an excessive load acts on the main body side contact 10. Therefore, it is preferable that the position of the unit side contact 20 in the vertical direction is not displaced while the main body side contact 10 and the unit side contact 20 are in contact.

[0060] <Avoiding collision between main body side contacts and unit side contacts> like Fig.11 and Fig.12 As shown, the guide surface 11 has an inclined surface 13 at a predetermined position. The inclined surface 13 provided on the guide surface 11 is used to avoid collision between the main body side contact 10 and the unit side contact 20 when the processing unit 2 is pulled out from the installation area 100A.

[0061] In order to avoid collision between the body-side contact 10 and the unit-side contact 20, the unit-side contact 20 needs to be displaced in the vertical direction to a position where it does not collide with the body-side contact 10. That is, the processing unit 2 needs to be displaced in the vertical direction.

[0062] However, the intermediate transfer unit 120 is disposed below the process unit 2. That is, the intermediate transfer belt 121 is disposed below the process unit 2. The intermediate transfer belt 121 is in contact with each photosensitive drum 111, which is a component of the process unit 2, in the vertical direction. Therefore, the vertical position of the process unit 2 cannot be further displaced downward.

[0063] Therefore, the inclined surface 13 is a surface that is inclined upward (hereinafter, simply referred to as upwardly inclined) from the upstream side to the downstream side in the direction in which the process unit 2 is pulled out when the process unit 2 is removed from the main frame 1. In other words, when the intermediate transfer belt 121 is arranged on one side of the vertical direction of the process unit 2, the inclined surface 13 is inclined from the upstream side to the downstream side in the direction in which the process unit 2 is pulled out when the process unit 2 is removed from the main frame 1, toward the other side opposite to the one side in the vertical direction. In further other words, the inclined surface 13 is inclined from the upstream side to the downstream side in the direction in which the process unit 2 is pulled out when the process unit 2 is removed from the main frame 1, in a direction away from the intermediate transfer belt 121.

[0064] In this way, when the processing unit 2 is pulled out from the installation area 100A, the position of the unit side contact 20 in the vertical direction is displaced by causing the roller 22 to move on the inclined surface 13. Since the inclined surface 13 is inclined upward, the position of the unit side contact 20 in the vertical direction is displaced upward. The larger the inclination angle of the inclined surface 13 with respect to the first direction D1 (i.e., the horizontal direction), the more the position of the unit side contact 20 in the vertical direction is displaced upward.

[0065] Below, refer to Fig.15 and Fig.16 Specific instructions. Fig.15 The upper, middle and lower figures are respectively Fig.16 For the convenience of explanation, Fig.16 The cell side contact 20 is not shown in detail, but instead, the area where the cell side contact 20 exists is indicated by a dotted line. Fig.16 Only two body-side contacts 10 adjacent to each other in the first direction D1 are shown.

[0066] When the processing unit 2 is installed in the installation area 100A, it becomes Fig.15 and Fig.16 In this state, since the main body side positioning part and the unit side positioning part are in an engaged state, the roller 22 does not contact the guide surface 11 (inclined surface 13). In addition, the main body side contact point 10 and the unit side contact point 20 are in contact.

[0067] From the state where the processing unit 2 is installed in the installation area 100A ( Fig.15 and Fig.16 In the initial stage of the extraction of the processing unit 2 (the state of each of the above figures), since the main body side positioning part and the unit side positioning part are in an engaged state, the roller 22 does not contact the guide surface 11 (inclined surface 13). Therefore, in the initial stage of the extraction of the processing unit 2, the position of the unit side contact 20 in the vertical direction does not shift. In the state where the unit side contact 20 is in contact with the main body side contact 10, the processing unit 2 moves to one side of the first direction D1 (i.e., the extraction direction Da) in a state where the position of the unit side contact 20 in the vertical direction does not shift.

[0068] Thereafter, the engagement between the main body side positioning portion and the unit side positioning portion is released. Fig.15 As shown in the middle figure, the roller 22 contacts the inclined surface 13. Fig.16 As shown in the middle figure of FIG, the contact between the main body side contact 10 (its arm portion 10a) and the unit side contact 20 is released. That is, until the contact between the main body side contact 10 and the unit side contact 20 is released, the main frame 1 supports the processing unit 2 in a state where the position of the unit side contact 20 does not shift in the vertical direction. Fig.16 In the middle figure, a part of the body side contact 10 overlaps with the unit side contact 20. However, because Fig.16 The state of the middle graph is equivalent to Fig.10 As shown in the above figure, the main body side contact 10 and the unit side contact 20 are not in contact.

[0069] When the roller 22 reaches and contacts the inclined surface 13, the roller 22 moves on the inclined surface 13. In this way, the vertical position of the unit-side contact 20 gradually moves upward. That is, after the contact between the body-side contact 10 and the unit-side contact 20 is released, the vertical position of the unit-side contact 20 gradually moves upward. In this way, the vertical position of the unit-side contact 20 moves to an avoidance position where it does not collide with the body-side contact 10 located on the downstream side of the withdrawal direction Da. Fig.16 The position of the unit-side contact 20 in the vertical direction shown in the lower figure is the avoidance position.

[0070] Here, the inclined surface 13 is provided in the portion of the guide surface 11 that contacts the roller 22 after the contact between the main body side contact 10 and the unit side contact 20 is released when the process unit 2 is pulled out from the installation area 100A. Thus, when the process unit 2 is pulled out from the installation area 100A, the unit side contact 20 does not shift in the vertical direction until the contact with the assigned main body side contact 10 is released. When the process unit 2 is pulled out from the installation area 100A, after the contact with the assigned main body side contact 10 is released, the unit side contact 20 shifts in the vertical direction to the avoidance position before reaching the main body side contact 10 located near the downstream side of the pulling-out direction of the process unit 2 (that is, the main body side contact 10 adjacent to the assigned main body side contact 10 in the pulling-out direction).

[0071] Below, refer to Fig.16 Here, the unit-side contact 20 of interest is denoted by reference numeral 202, and the main body-side contact 10 assigned to the unit-side contact 202 is denoted by reference numeral 102. In addition, the main body-side contact 10 located on the downstream side of the main body-side contact 102 in the direction of extraction of the processing unit 2 is denoted by reference numeral 101, and the unit-side contact 20 assigned to the main body-side contact 101 is denoted by reference numeral 201. Furthermore, the unit-side contact 20 located on the upstream side of the unit-side contact 202 in the direction of extraction of the processing unit 2 is denoted by reference numeral 203.

[0072] like Fig.16 As shown, after the contact between the unit side contact 202 and the assigned body side contact 102 is released, its vertical position gradually moves upward (from Fig.16 The state change of the middle graph is Figure 6The unit-side contact 202 reaches the avoidance position by gradually shifting its vertical position upward.

[0073] At this time, the unit-side contact 202 has not reached the main body-side contact 101. That is, the unit-side contact 202 is displaced in the vertical direction to the avoidance position between the assigned main body-side contact 102 and the main body-side contact 101 located downstream in the withdrawal direction of the main body-side contact 102 in the first direction D1. In this way, the unit-side contact 202 does not collide with the main body-side contact 101.

[0074] Subsequently, until the unit-side contact 20 on the most upstream side in the drawing direction of the processing unit 2 passes the main body-side contact 10 on the most downstream side in the drawing direction, the vertical position of the unit-side contact 20 is maintained at the avoidance position. Furthermore, after the vertical position of the unit-side contact 20 reaches the avoidance position, the guide surface 11 becomes inclined downward in the drawing direction of the processing unit 2. If the roller 22 moves on the downwardly inclined surface of the guide surface 11, the vertical position of the unit-side contact 20 is displaced downward. However, the position where the main body-side contact 10 collides with the unit-side contact 20 does not displace.

[0075] In this embodiment, by providing the inclined surface 13 on the guide surface 11, when the process unit 2 is pulled out from the installation area 100A, the position of the unit side contact 20 in the vertical direction can be displaced to the avoidance position where it does not collide with the main body side contact 10 in the first direction D1, and the position of the unit side contact 20 in the vertical direction can be maintained at the avoidance position. In this way, when the operator performs the operation of removing the process unit 2 from the device body of the image forming apparatus 100, it is easy to prevent the unit side contact 20 and the main body side contact 10 from colliding in the first direction D1. In other words, it is possible to prevent a malfunction caused by the collision between the main body side contact 10 and the unit side contact 20. In other words, the process unit 2 can be safely removed.

[0076] In the above configuration, the operator who removes the processing unit 2 from the device body does not need to pay attention to the positional relationship between the body side contact point 10 and the unit side contact point 20, and can simply pull out the processing unit 2 in a manner that the roller 22 moves on the guide surface 11, so it is very convenient. In other words, the removal operation of the processing unit 2 becomes easy. In other words, the operability of the removal operation of the processing unit 2 is improved.

[0077] Furthermore, there is no need to separately provide a dedicated member for disassembling the processing unit 2. That is, it is sufficient to provide the inclined surface 13 on the guide surface 11. This prevents the structure from being complicated and suppresses the increase in cost.

[0078] Furthermore, in the present embodiment, the intermediate transfer belt 121 is arranged below one side in the vertical direction of the process unit 2. Therefore, the inclined surface 13 is inclined upward from the upstream side to the downstream side in the direction of extraction of the process unit 2. That is, the inclined surface 13 is inclined toward the other side opposite to the one side in the vertical direction from the upstream side to the downstream side in the direction of extraction of the process unit 2. Thus, even if the position of the process unit 2 in the vertical direction is displaced (in other words, even if the position of the unit-side contact 20 in the vertical direction is displaced to the avoidance position), the process unit 2 will not interfere with the intermediate transfer belt 121.

[0079] For example, although not shown, depending on the type of the image forming apparatus 100, the intermediate transfer belt 121 may be arranged above the other side of the vertical direction of the process unit 2. In this case, the inclined surface 13 is inclined downward from the upstream side to the downstream side in the direction of extraction of the process unit 2. That is, the inclined surface 13 is inclined from the upstream side to the downstream side in the direction of extraction of the process unit 2 toward one side of the vertical direction. In this way, the position of the process unit 2 in the vertical direction can be displaced without interfering with the intermediate transfer belt 121.

[0080] Furthermore, in the present embodiment, the inclined surface 13 is provided in the portion of the guide surface 11 that contacts the roller 22 after the contact between the main body side contact 10 and the unit side contact 20 is released when the process unit 2 is pulled out from the mounting area 100A. Furthermore, when the process unit 2 is pulled out from the mounting area 100A, the main frame 1 supports the process unit 2 in a state where the position of the unit side contact 20 does not shift in the vertical direction until the contact between the main body side contact 10 and the unit side contact 20 is released. In other words, when the process unit 2 is pulled out from the mounting area 100A, the position of the unit side contact 20 does not shift in the vertical direction until the contact between the main body side contact 10 and the unit side contact 20 is released, and the roller 22 travels on the inclined surface 13 after the contact between the main body side contact 10 and the unit side contact 20 is released.

[0081] This can suppress vertical displacement of the unit-side contact 20 while the body-side contact 10 is in contact with the unit-side contact 20. As a result, when the process unit 2 is pulled out from the mounting area 100A, no extra load is applied to the body-side contact 10.

[0082] The embodiments of the present invention are all illustrative and non-restrictive. The scope of the present invention is not limited to the description of the above embodiments, but is indicated by the claims, and includes contents equivalent to the claims and all modifications within the scope of the claims.

Claims

1. An image forming device, characterized in that include: a main frame having a mounting area; a processing unit installed in a detachable manner relative to the installation area, and can be removed from the main frame by being pulled out from a state installed in the installation area to one side of a first direction perpendicular to the up-down direction, the processing unit performing a development process of developing an electrostatic latent image into a toner image; A plurality of main body side contacts are arranged on the main body frame, protrude toward the installation area and in a second direction that is horizontally perpendicular to the first direction, and are spaced apart from each other in the first direction; as well as A plurality of unit-side contacts are arranged on the processing unit and are respectively assigned to the plurality of the main body-side contacts. When the processing unit is installed in the installation area, the unit-side contacts are in contact with the assigned main body-side contacts. The main frame has a guide surface extending in the first direction, The processing unit has a roller, and the roller travels on the guide surface when the processing unit is loaded and unloaded relative to the installation area. The guide surface has an inclined surface that is inclined in either an upward or downward direction from an upstream side to a downstream side in a pulling-out direction when the processing unit is pulled out from the installation area. When the processing unit is pulled out from the installation area, the roller moves on the inclined surface, and the vertical position of the unit-side contact is displaced to an avoidance position that does not collide with the main body-side contact located on the downstream side of the pulling direction.

2. The image forming apparatus according to claim 1, wherein: The inclined surface is provided at a portion of the guide surface that contacts the roller after the contact between the main body-side contact and the unit-side contact is released when the processing unit is pulled out from the installation area.

3. The image forming apparatus according to claim 1 or 2, characterized in that: When the processing unit is pulled out from the installation area, the main frame supports the processing unit in a state where the position of the unit-side contact does not shift in the vertical direction until the contact between the main body-side contact and the unit-side contact is released.

4. The image forming apparatus according to claim 1 or 2, wherein: When the processing unit is pulled out from the installation area, the unit-side contact is displaced in the vertical direction to the avoidance position before reaching the main body-side contact located near the assigned main body-side contact on the downstream side in the pulling-out direction.

5. The image forming apparatus according to claim 1 or 2, characterized in that: An intermediate transfer body is provided for receiving the transfer of the toner image from the process unit. The intermediate transfer body is arranged on one side in the vertical direction of the processing unit. The inclined surface is inclined from the upstream side to the downstream side in the extraction direction, toward the other side opposite to the one side in the up-down direction.

6. The image forming apparatus according to claim 1, wherein: The main body side contact is a helical torsion spring, which has a coil spring portion and a pair of arm portions extending from both ends of the coil spring portion in a tangential direction, and the up-down direction is the axial direction of the coil spring portion. The arm portion of one of the coil torsion springs protrudes toward the mounting area, so that the body-side contact point can be brought into contact with the unit-side contact point. In a state where the processing unit is mounted in the mounting area, one of the arm portions is pressed in a torsion direction of the coil torsion spring.

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