Image forming apparatus

Abstract

To provide an image forming apparatus that has a movable developing unit, and to prevent a variation of positions of a light emitting element and a light receiving element with respect to the developing unit.SOLUTION: An image forming apparatus has: (i) an apparatus body that includes a first connection part; (ii) a drum unit; (iii) a developing unit that has a storage part storing toner and is movable to a contact position and a separation position; (iv) a detection part that has a light emitting element, a light receiving element, and a second connection part at which the light emitting element and the light receiving element are electrically connected with each other, and is attached to the developing unit; and (v) a connection member that is connected with the first connection part and the second connection part so that the first connection part and the second connection part are electrically connected with each other. A length of the connection member is longer than a first distance from the first connection part to the second connection part when the developing unit is at the contact position and a second distance from the first connection part to the second connection part when the developing unit is at the separation position.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus using an electrophotographic method. [Background technology]

[0002] In an electrophotographic image forming apparatus, an electrostatic latent image formed on the surface of a photosensitive drum is developed with toner as a developer.

[0003] Patent Document 1 discloses a configuration in which a developing unit including a toner container that stores toner and a developing roller is movable so that the developing roller can be brought into contact with and separated from a photosensitive drum. Furthermore, Patent Document 1 discloses a configuration in which, in order to detect the amount of toner stored in the toner container, light is irradiated onto the toner container from a light-emitting element in the device main body, and the light that passes through the toner container is received by a light-receiving element. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-295596 Summary of the Invention [Problem to be solved by the invention]

[0005] In the image forming apparatus of Patent Document 1, the light emitting element and the light receiving element are disposed in the apparatus body and are not fixed to the developing unit, so the positions of the light emitting element and the light receiving element relative to the developing unit may vary.

[0006] An object of the present invention is to suppress variations in the positions of the light emitting element and the light receiving element relative to the developing unit in an image forming apparatus having a movable developing unit. [Means for solving the problem]

[0007] One of the inventions of the present application is as follows.

[0008] An image forming apparatus for forming an image on a recording material, a device body having a first connection portion; a drum unit having a photosensitive drum and housed in the device main body; a developing unit housed in the device main body, the developing unit having a container for housing toner and a developing roller for supplying the toner to the photosensitive drum, the developing unit being configured to be movable relative to the drum unit between a contact position where the developing roller contacts the photosensitive drum and a separation position where the developing roller is separated from the photosensitive drum; a detection section attached to the developing unit, the detection section having a light-emitting element, a light-receiving element configured to receive light emitted from the light-emitting element and passing through the storage section, and a second connection section to which the light-emitting element and the light-receiving element are electrically connected; a connection member connected to the first connection portion and the second connection portion so that the first connection portion and the second connection portion are electrically connected; and the detection portion is attached to the development unit such that the second connection portion is displaced relative to the first connection portion when the development unit moves between the contact position and the separated position; An image forming apparatus characterized in that the length of the connecting member is longer than a first distance from the first connection portion to the second connection portion when the developing unit is in the abutment position, and a second distance from the first connection portion to the second connection portion when the developing unit is in the separated position. [Effects of the Invention]

[0009] As described above, according to the present invention, in an image forming apparatus having a movable developing unit, it is possible to suppress variations in the positions of the light emitting element and the light receiving element relative to the developing unit. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a perspective view of an image forming apparatus. [Figure 2] FIG. 2 is a diagram illustrating the internal configuration of the image forming apparatus. [Figure 3] FIG. 2 is a diagram illustrating the internal configuration of the image forming apparatus. [Figure 4] FIG. 2 is a top view of the image forming apparatus. [Figure 5] 1A is a perspective view showing a process unit, FIG. 1B is a perspective view showing a wiring board and a substrate holding member, and FIG. 1C is a perspective view showing a state in which the wiring board and the substrate holding member are attached to the process unit. [Figure 6] 1A and 1B are cross-sectional views of a process unit. [Figure 7] FIG. 4 is a circuit diagram showing a remaining toner detection sensor. [Figure 8] (a) is a diagram showing the support unit in a retracted state, (b) is a diagram showing the support unit in a support start state, and (c) is a diagram showing the support unit in a support state. [Figure 9] FIG. 10 is a top view of an image forming apparatus according to a second embodiment. [Figure 10] FIG. 10 is a diagram illustrating the arrangement of connection members according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] The following describes in detail exemplary embodiments of the present invention with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the embodiments may be changed as appropriate depending on the configuration of the device to which the invention is applied and various conditions. In other words, the scope of the present invention is not intended to be limited to the following embodiments. Furthermore, in the drawings used in the following description, for the purpose of explanation, some components or parts of the components may be omitted or simplified. [Example]

[0012] <Overall configuration of image forming apparatus> The overall configuration of an image forming apparatus 1 in this embodiment will be described using Figures 1 and 2. The image forming apparatus 1 in this embodiment is a monochrome laser beam printer that uses an electrophotographic process. The image forming apparatus 1 is capable of performing an image forming operation that forms an image using a developer (toner) on a recording material P in accordance with image information transmitted from an external device such as a personal computer. Examples of the recording material P include recording paper, label paper, overhead projector sheets, and cloth.

[0013] In the following description, the height direction of the image forming apparatus 1 (the direction opposite to the direction of gravity) when the image forming apparatus 1 is installed on a horizontal surface is referred to as the Z direction. The direction that intersects with the Z direction and is parallel to the direction of the rotation axis of the photosensitive drum 11 (main scanning direction), which will be described later, is referred to as the X direction. The direction that intersects with the X and Z directions is referred to as the Y direction. The X, Y, and Z directions preferably intersect perpendicularly with each other. For convenience, the positive side of the X direction is referred to as the right side and the negative side as the left side; the positive side of the Y direction is referred to as the front side or front side and the negative side of the Y direction is referred to as the rear side or back side; and the positive side of the Z direction is referred to as the upper side and the negative side as the lower side. In this embodiment, the Z direction is parallel to the vertical direction, and the X and Y directions are parallel to the horizontal direction.

[0014] Fig. 1 shows a perspective view of the image forming apparatus 1, and Fig. 2 is a diagram illustrating the internal configuration of the image forming apparatus 1 as viewed from the X direction (the direction of the rotation axis of the photosensitive drum 11). Fig. 2 mainly shows members related to the image formation process.

[0015] 1, the image forming apparatus 1 has a feed tray 4 that stores recording materials P, and a discharge tray (opening / closing member) 14 on which discharged recording materials P are stacked. The feed tray 4 can be pulled out in the Y direction, allowing the user to replenish recording materials P. The recording materials P that have been fed from the feed tray 4 and on which images have been formed are discharged from a discharge port 15 in the discharge direction shown in FIG. 1, and are stacked on the discharge tray 14. In this embodiment, the discharge direction is parallel to the Y direction.

[0016] A front cover 70 is provided on a portion of the end face (part of the front face) of the image forming apparatus 1 downstream in the discharge direction, covering the control board 100. An exterior cover 71 is provided on a portion of the front face other than the portion where the front cover 70 is provided, as well as on the side and top faces of the image forming apparatus 1. The front cover 70, the exterior cover 71, and the discharge tray 14 described above together form a housing (apparatus main body, main body frame) 72 of the image forming apparatus 1. Here, the housing 72 is a member that covers the entire image forming apparatus 1 and houses the scanner unit 50, process unit 500, etc., which will be described later. The discharge port 15 described above is an opening formed in a portion of the housing 72, and the recording material P is discharged to the outside of the image forming apparatus 1 through this opening. The recording material P discharged from the discharge port 15 is stacked on the upper surface (stacking portion) provided on the discharge tray 14.

[0017] The image forming apparatus 1 includes a process unit 500 having a photosensitive unit (drum unit 300) and a developing unit 230. The process unit 500 is housed in a housing 72. The photosensitive unit 300 includes a photosensitive drum 11 and a charging roller (charging member) 17. The developing unit 230 includes a container 18 for storing toner, and a developing roller 12. The photosensitive drum 11 is an image carrier that carries an electrostatic latent image. The developing roller 12 is a developer carrier that carries toner as a developer. The developing roller 12 supplies toner to the photosensitive drum 11, thereby developing the electrostatic latent image formed on the photosensitive drum 11 with the toner. In this embodiment, the developing roller 12 develops the electrostatic latent image while in contact with the photosensitive drum 11, as shown in FIG. 2.

[0018] As described above, the housing 72 houses the process unit 500 (the photosensitive unit 300 and the developing unit 230) and includes the discharge tray 14. The discharge tray 14 is attached to the exterior cover 71.

[0019] 2, the flow of the image forming operation (image forming process) on the recording material P will be described. When image information is sent to the image forming apparatus 1, the photosensitive drum 11, which is a rotating body, is rotated in the direction of arrow R at a predetermined peripheral speed (process speed) based on a print start signal.

[0020] Based on input image information, the scanner unit 50 irradiates laser light onto the photosensitive drum 11. The scanner unit 50 includes a laser oscillator that outputs laser light, a polygon mirror and a lens for irradiating the laser light onto the photosensitive drum 11, a scanner motor for rotating the polygon mirror, and a frame that supports these components.

[0021] The photosensitive drum 11 is pre-charged by the charging roller 17, and an electrostatic latent image is formed on the photosensitive drum 11 by irradiating it with laser light. Thereafter, the toner contained in the container 18 is conveyed to the photosensitive drum 11 by the developing roller 12, whereby the electrostatic latent image is developed and a toner image is formed on the photosensitive drum 11.

[0022] In parallel with the image formation process described above, recording materials P are fed from the feed tray 4. A pickup roller 3, a feed roller 5a, and a pair of conveying rollers 5c are provided on the conveyance path of the image forming apparatus 1. The pickup roller 3 comes into contact with the uppermost recording material P stored in the feed tray 4, and feeds the recording material P by rotating the roller itself. The feed roller 5a and the separation roller 5b that comes into pressure contact with it form a separation nip. If multiple sheets of recording materials P are fed into the separation nip due to the influence of friction between the recording materials P, the feed roller 5a and the separation roller 5b separate the multiple sheets of recording materials P and feed only the uppermost one downstream.

[0023] The recording material P fed from the feed tray 4 is conveyed by a pair of conveying rollers 5c toward a transfer roller 7. A transfer bias is applied to the transfer roller 7, so that the toner image formed on the photosensitive drum 11 is transferred onto the recording material P. The recording material P onto which the toner image has been transferred by the transfer roller 7 is heated and pressurized by a fixing device 9, so that the toner image is fixed onto the recording material P. The fixing device 9 is composed of a heating roller 9a incorporating a fixing heater, and a pressure roller 9b that is urged toward the heating roller 9a. Then, the recording material P onto which the toner image has been fixed is discharged onto a discharge tray 14 by a pair of discharge rollers 10.

[0024] When an image is formed on both sides of the recording material P, the pair of discharge rollers 10 switches back the recording material P with the image formed on its first side, thereby guiding the recording material P to a double-sided conveying path 16. The recording material P guided to the double-sided conveying path 16 is conveyed again toward the transfer roller 7 by the pair of double-sided conveying rollers 5d and the pair of conveying rollers 5c. After an image is formed on the second side of the recording material P, which is behind the first side, by the transfer roller 7, the recording material P is discharged onto a discharge tray 14 by the pair of discharge rollers 10. After the toner image is transferred onto the recording material P, any toner remaining on the photosensitive drum 11 is cleaned by a cleaning unit 13.

[0025] Housing 72 has control board 100. Control board 100 includes a wiring board (first board, first board portion, first printed circuit board) 101, a control unit (CPU, arithmetic unit) 199, and a connector (first connection portion, main body side connection portion) 131. Control unit 199 and connector 131 are attached to wiring board 101 by soldering, and control unit 199 and connector 131 are electrically connected.

[0026] A detection section 150 is attached to the developing unit 230. The detection section 150 includes a wiring board (second board, second board section, second printed circuit board) 151, a connector (second connection section, unit side connection section) 152, and a toner remaining amount sensor 51 (described later). The connector 152 and the toner remaining amount sensor 51 (a light-emitting section 51a and a light-receiving section 51b (described later)) are attached to the wiring board 151 by soldering, and the connector 152 and the toner remaining amount sensor 51 are electrically connected.

[0027] The control unit 199 controls the operation of the image forming apparatus 1 to perform an image forming operation on the recording material P. As shown in Fig. 2, the control board 100 is oriented such that the surface of the wiring board 101 intersects with the discharge direction. Furthermore, the wiring board 101 is provided between the front cover 70 and the scanner unit 50 in the discharge direction. In this embodiment, the detection unit 150 and the control board 100 are positioned to face each other, but they may also be positioned not to face each other.

[0028] The image forming apparatus 1 has a connection member 141 connected to the connector 131 and the connector 152 so that the connector 131 and the connector 152 are electrically connected. The connection member 141 functions as a signal input / output line that electrically connects the control board 100 and the detection unit 150 via the connector 151 and the connector 131.

[0029] It is preferable to use an electric wire having a conductor covered with an insulating layer as the connecting member 141. A plurality of electric wires, a cable in which a plurality of electric wires are bundled together, or a harness in which connector members are attached to both ends of a plurality of electric wires can be used as the connecting member 141. Furthermore, a so-called flexible flat cable can also be used as the connecting member 141.

[0030] <Developing Roller Contact / Separation Operation> 2 and 3, the contact and separation operation of the developing roller 12 with respect to the photosensitive drum 11 will be described. Fig. 3 is a diagram illustrating the internal configuration of the image forming apparatus 1 as viewed from the X direction (the direction of the rotation axis of the photosensitive drum 11).

[0031] The developing unit 230 is configured to be movable relative to the housing 72 and the photosensitive unit 300. In other words, the developing unit 230 is configured to be movable relative to the photosensitive drum 11. By moving relative to the photosensitive unit 300, the developing unit 230 can move between a contact position (FIG. 2) where the developing roller 12 contacts the photosensitive drum 11 and a separation position (FIG. 3) where the developing roller 12 is separated from the photosensitive drum 11.

[0032] The housing 72 is provided with a moving unit (developing moving unit, moving device) 400 that moves the developing unit 230 between the contact position and the separated position. In this embodiment, the moving unit 400 pushes the developing unit 230, causing the developing unit 230 to move from the contact position to the separated position, and the moving unit 400 moves away from the developing unit 230, causing the developing unit 230 to move from the separated position to the developing unit. However, the present invention is not limited to this. For example, the moving unit 400 may push the developing unit 230, causing the developing unit 230 to move from the separated position to the contact position, and the moving unit 400 may move away from the developing unit 230, causing the developing unit 230 to move from the contact position to the separated position. Alternatively, the moving unit 400 may push the developing unit 230, causing the developing unit 230 to move from the separated position to the contact position, and from the abutment position to the separated position.

[0033] By separating the developing roller 12 from the photosensitive drum 11 as necessary, the developing roller 12 and the photosensitive drum 11 can be protected.

[0034] In this embodiment, when developing unit 230 is in at least one of the contact position and the separated position, wiring board 101 and wiring board 151 face each other.

[0035] <Scanner irradiation range> 4 is a top view of the image forming apparatus 1 with the exterior cover 71 removed. The housing 72 has side walls 73 and 74. The connecting member 141 is disposed so as to avoid the irradiation area of ​​the laser emitted from the scanner unit 50 (the hatched area in a grid pattern in FIG. 4). Specifically, in the direction of the rotation axis of the photosensitive drum 11, the connecting member 141 is positioned outside the irradiation area of ​​the laser emitted from the scanner unit 50.

[0036] <Process unit configuration> The process unit 500 will be described with reference to Figures 5 and 6. Figure 5(a) is a perspective view showing the process unit 500. Figure 5(b) is a perspective view showing the wiring board 151 and the substrate holding member 710, and Figure 5(c) is a perspective view showing the wiring board 151 and the substrate holding member 710 attached to the process unit 500. Figures 6(a) and 6(b) are cross-sectional views of the process unit 500. Figure 6(a) is a cross-sectional view in a direction perpendicular to the axial direction of the developing roller 12, and Figure 6(b) is a cross-sectional view taken along line 6B-6B of Figure 6(a).

[0037] As shown in Figure 5(a), the developing unit 230 of the process unit 500 has a developing container 320 and a developing lid 321. The developing container 320 and the developing lid 321 are joined together to form a frame (developing frame) 340 of the developing unit 230. The frame 340 is provided with a storage section 18 (see Figures 2 and 3) that stores toner. The developing roller 12 is supported by the frame 340.

[0038] The developing device lid 321, which constitutes part of the frame 340, has substrate positioning members 321a and 321b and substrate fixing members 321c and 321d, and a light guide (light guiding member, light path forming member) 610 is installed between the substrate fixing members 321c and 321d of the developing device lid 321. The light guide 610 has a first guide member 610a and a second guide member 610b, and the first guide member 610a guides light emitted from a light emitting member 51a (described later) into the housing member 18 of the frame 340. The light that has passed through the second guide member 610b, the first guide member 610a, and the housing member 18 is guided to a light receiving member 51b (described later).

[0039] The substrate positioning units 321a and 321b as positioning units are disposed outside the substrate fixing units 321c and 321d, respectively, in the longitudinal direction LD of the frame 340. The longitudinal direction LD of the frame 340 is the same as the longitudinal direction LD of the process unit 20, the direction of the rotation axis of the photosensitive drum 11, and the direction of the rotation axis of the developing roller 12.

[0040] 5(c), in this embodiment, the wiring board 151 and the substrate holding member 710 are assembled to the developing device lid 321. The substrate holding member 710 is assembled to the developing device lid 321 in a state where it is sandwiched between the developing device lid 321 and the wiring board 151.

[0041] The developing unit 230 is fitted with a detection unit 150 having a light-emitting unit (light-emitting element) 51a, a light-receiving unit (light-receiving element) 51b configured to receive light emitted from the light-emitting unit 51a and passed through the storage unit 18 via the light guide 610, and a connector 152. The light-emitting unit 51a and the light-receiving unit 51b are electrically connected to the connector 152.

[0042] As shown in FIG. 5( b), the wiring board 151 is provided with a light-emitting unit 51a, a light-receiving unit 51b, and a connector 152. In this embodiment, an LED is used for the light-emitting unit 51a, and a phototransistor that is turned on by light from the LED is used for the light-receiving unit 51b, but this is not limiting. For example, a halogen lamp or a fluorescent lamp may be used for the light-emitting unit 51a, and a photodiode or an avalanche photodiode may be used for the light-receiving unit 51b. A connecting member 141 is connected to the connector 152. This electrically connects the light-emitting unit 51a and the light-receiving unit 51b to the connector 131 via the connector 152 and the connecting member 141. As a result, power can be supplied to the light-emitting unit 51a, and a signal output from the light-receiving unit 51b can be transmitted to the control board 100.

[0043] Furthermore, wiring board 151 has positioning holes 151a and 151b into which board positioning members 321a and 321b are inserted and engaged, and board fixing holes 700c and 700d through which screws for fixing to board fixing portions 321c and 321d can pass.

[0044] Similarly, the board holding member 710 has positioning holes 710a and 710b into which the board positioning members 321a and 321b are inserted and engaged, and board fixing holes 710c and 710d through which screws for fixing the board fixing members 321c and 321d can pass. Furthermore, the board holding member 710 has a first hole 711a into which the first guide member 610a of the light guide 610 is inserted, and a second hole 711b into which the second guide member 610b of the light guide 610 is inserted. The first hole 711a and the second hole 711b have a cylindrical shape. The board holding member 710, acting as a holder, holds the wiring board 151.

[0045] The substrate holding member 710 is positioned relative to the developing device lid 321 by the substrate positioning members 321a and 321b of the developing device lid 321 penetrating and engaging with the positioning holes 710a and 710b. The wiring board 151 is also positioned relative to the developing device lid 321 by the substrate positioning members 321a and 321b of the developing device lid 321 penetrating and engaging with the positioning holes 151a and 151b. In this way, the substrate positioning members 321a and 321b are commonly used to position the substrate holding member 710 and the wiring board 151, so that the developing device lid 321, the substrate holding member 710, and the wiring board 151 can be positioned with higher accuracy.

[0046] Furthermore, with the substrate holding member 710 and the wiring board 151 positioned relative to the developing device lid 321, screws are inserted into the substrate fixing holes 700c, 700d, 710c, and 710d, and the screws are fixed to the substrate fixing portions 321c and 321d of the developing device lid 321. As a result, the substrate holding member 710 and the wiring board 151 are fixed to the developing device lid 321 with one screw, and the substrate holding member 710 and the wiring board 151 are fixed to the developing device lid 321.

[0047] When the substrate holding member 710 and the wiring board 151 are assembled to the developing cover 321, the first guide portion 610a of the light guide 610 is inserted into the first hole 711a of the substrate holding member 710. The first guide portion 610a is then positioned in proximity to the light-emitting portion 51a of the wiring board 151. Similarly, the second guide portion 610b of the light guide 610 is inserted into the second hole 711b of the substrate holding member 710. The second guide portion 610b is then positioned in proximity to the light-receiving portion 51b of the wiring board 151.

[0048] As described above, the substrate holding member 710 and the wiring board 151 are accurately positioned on the developing cover 321, so that the light emitted from the light-emitting portion 51a is reliably guided by the first guide portion 610a. Then, the light guided by the first guide portion 610a to the accommodation portion (accommodation chamber) 18 inside the frame body 340 is emitted from the first guide portion 610a in the longitudinal direction LD.

[0049] The light traveling along the optical path Q1 inside the storage unit 18 is guided by the second guide portion 610b to the outside of the frame 340. Because the second guide portion 610b is disposed close to the light receiving portion 51b, the light emitted from the second guide portion 610b is reliably received by the light receiving portion 51b. This improves the accuracy of detecting the remaining toner amount by the light emitting portion 51a and the light receiving portion 51b.

[0050] Here, the arrangement of the light-emitting unit 51a and the light-receiving unit 51b will be described in more detail. In the frame 340, the light-emitting unit 51a and the light-receiving unit 51b are arranged at the end opposite the end where the developing roller 12 is arranged. The light-emitting unit 51a and the light-receiving unit 51b are also provided in the central portion of the storage unit 18 in the longitudinal direction LD. By providing the light-emitting unit 51a and the light-receiving unit 51b in the central portion of the storage unit 18, the remaining amount of toner in the storage unit 18 can be detected accurately. That is, while developer (toner) may be unevenly distributed at the ends of the storage unit 18 in the longitudinal direction LD, the central portion of the storage unit 18 has less uneven distribution of developer, so the actual remaining amount of toner can be detected.

[0051] When the developing unit 230 moves between the contact position and the separated position, the frame 340 also moves. Because the detection unit 150 is fixed to the frame 340 via the wiring board 151, when the developing unit 230 moves between the contact position and the separated position, the detection unit 150 also moves (displaces) together with the developing unit 230 relative to the photosensitive unit 300 and the control board 100 of the housing 72. The detection unit 150 is attached to the developing unit 230 such that the connector 152 displaces relative to the connector 131 when the developing unit 230 moves between the contact position and the separated position.

[0052] <Detecting remaining toner> The control unit 199 performs a detection operation (toner remaining amount detection) to detect the amount of toner contained in the container 18 based on the signal output from the light receiving unit 51b.

[0053] 7 is a circuit diagram showing an example of the circuit configuration of the remaining toner amount sensor 51 mounted on the detection unit 150. The remaining toner amount sensor 51 has a light-emitting unit 51a and a light-receiving unit 51b. The light-emitting unit 51a and the light-receiving unit 51b are connected to the connector 131 of the control board 100 via a connector 152 and a connecting member 141.

[0054] The light-emitting element 51a is connected to a power supply voltage Vcc and a current-limiting resistor R1, and the light-emitting element 51a emits light using a current determined by the current-limiting resistor R1. Light emitted from the light-emitting element 51a passes through an optical path Q1 (not shown) and is received by the light-receiving element 51b. The collector terminal of the light-receiving element 51b is connected to the power supply voltage Vcc, and the emitter terminal is connected to a detection resistor R2. The light-receiving element 51b, which is a phototransistor, receives the light emitted from the light-emitting element 51a and outputs a signal (current) corresponding to the amount of light received. This signal is converted to a voltage V1 by the detection resistor R2 and input to the A / D conversion unit 95 of the control unit 90 included in the control board 100. In other words, the light-receiving element 51b changes its output value according to the amount of toner (developer) contained in the container 18.

[0055] As described above, when the toner remaining amount sensor 51 of the detection unit 150 is mounted on the development unit 230, it is possible to shorten the distance of the optical path Q1 compared to when the toner remaining amount detection sensor 51 is mounted on the housing 72. This makes it possible to improve the positional accuracy of the light-emitting unit 51a and the light-receiving unit 51b relative to the optical path Q1 compared to a configuration in which the toner remaining amount sensor 51 is attached to the housing 72. In other words, the variation in the reception of light emitted from the light-emitting unit 51a by the light-receiving unit 51b is reduced, thereby improving the accuracy of toner detection.

[0056] The control unit 199 determines whether the light receiving unit 51b has received light from the light emitting unit 51a based on the input voltage level. When the agitating member 34 (see FIG. 6(a)) contained in the container 18 rotates and the toner is agitated for a certain period of time, the control unit 199 can calculate the amount of toner in the container 18 based on the length of time that the light receiving unit 51b detects light and the intensity of the light.

[0057] <Length of connecting member> As described above, when the developing unit 230 moves between the abutting position and the separated position, the connector 152 is displaced relative to the connector 131, causing the distance between the connector 152 and the connector 131 to vary. Therefore, if the length of the connecting member 141 is too short, the movement of the developing unit 230 will be hindered by the connecting member 141. Therefore, the length of the connecting member 141 is set so as not to hinder the movement of the developing unit 230. The length of the connecting member 141 in this embodiment will be described below.

[0058] 2 and 3, when the developing unit 230 is in the abutting position, the distance between the connector 131 of the control board 100 and the connector 152 of the detection unit 150 is defined as D1 (first distance). When the developing unit 230 is in the separated position, the distance between the connector 131 of the control board 100 and the connector 152 of the detection unit 150 is defined as D2 (second distance). The length of the connecting member 141 is longer than D1 and D2 so as not to interfere with the movement of the developing unit 230. Furthermore, it is preferable that the connecting member 141 be flexible.

[0059] The distance between connector 131 and connector 152 is specifically the shortest distance between the portions into which connecting member 141 is inserted. The length of connecting member 141 is the length from connector 131 to connector 152 along the surface of connecting member 141.

[0060] In this embodiment, D1 is longer than D2, that is, the length of the connection member 141 is longer than D1.

[0061] As described above, when the developing unit 230 moves, the detecting unit 150 also moves in conjunction with it. At this time, a repulsive force acts on the connector 152 of the detecting unit 150, causing the connecting member 141 to return to its original position, and a force in the opposite direction to the movement direction of the developing unit 230 is applied. If the repulsive force of the connecting member 141 becomes greater than the force required to move the developing unit 230, the developing unit 230 cannot move to the desired position, and the contact and separation operation of the developing unit 230 is hindered.

[0062] Therefore, by making the length of the connecting member 141 longer than D1 and D2, the repulsive force of the connecting member 141 can be reduced so as not to interfere with the movement of the developing unit 230. In other words, the length of the connecting member 141 is set to be equal to or greater than D1 and D2.

[0063] It is preferable that the length of the connecting member 141 be longer than either D1 or D2. In this embodiment, the length of the connecting member 141 is set so that the difference between the connecting member 141 and D1 is greater than the difference between D1 and D2. Furthermore, since the connecting member 141 has an excess length, a portion of the connecting member 141 may be bent to be attached to the connector 152 and the connector 131. In this case, by arranging the bent portion of the connecting member 141 closer to the connector 152 than the connector 131, it is possible to minimize the effect of the repulsive force of the connecting member 141, which occurs when the developing unit 230 moves, on the connector 152. In other words, it is preferable that the bent portion of the connecting member 141 be arranged so that the distance between the bent portion and the connector 152 is shorter than the distance between the bent portion and the connector 131.

[0064] As described above, according to the configuration of this embodiment, by attaching the detection unit 150 to the developing unit 230, even when the developing unit 230 moves between the contact position and the separation position, it is possible to prevent misalignment of the light-emitting unit 51a, the light-receiving unit 51b, and the developing unit 230. Furthermore, since the connecting member 141 has a sufficient length, it is possible to prevent the connecting member 141 from interfering with the contact and separation operation of the developing unit 230.

[0065] In this embodiment, the connecting member 141 connects the detection unit 150 for detecting the remaining amount of toner to the control board 100, but it may also be used to connect parts having other functions to the housing 72.

[0066] Furthermore, because the length of connecting member 141 is longer than D1 and D2, the electrical connection between connector 131 and connector 152 is maintained both when developing unit 230 is in the contact position and when it is in the separated position. Therefore, control unit 199 can detect the remaining toner amount both when developing unit 230 is in the contact position and when it is in the separated position. [Example]

[0067] In the second embodiment, an image forming apparatus 1A and a developing unit 230A will be described, which are partially different in configuration from the image forming apparatus 1 of the first embodiment. Configurations similar to those described in the first embodiment may be omitted from description or illustration, or may be described by assigning the same reference numerals in the drawings.

[0068] Image forming apparatus 1A according to this embodiment has a developing unit 230A. As will be described later, developing unit 230A has, in addition to the configuration of developing device 230 according to embodiment 1, a receiving portion 202 to which a replenishing pack (replenishing container) 210 that replenishing toner to storage portion 18 is removably attached. As in embodiment 1, developing unit 230A also has a detecting portion 150 attached. Hereinafter, image forming apparatus 1A according to this embodiment will be described with reference to FIGS. 8 and 9.

[0069] Fig. 8 is an explanatory diagram of the support unit 250. Fig. 8(a) is a diagram showing the support unit 250 in a retracted state. Fig. 8(b) is a diagram showing the support unit 250 in a support start state. Fig. 8(c) is a diagram showing the support unit 250 in a support state. Figs. 8(a), 8(b), and 8(c) are side views seen along the direction of the rotation axis of the photosensitive drum 11.

[0070] As described above, the developing unit 230A according to this embodiment has a receiving portion 202 to which the supply pack 210 is attached. On the other hand, the housing 72 of the image forming apparatus 1A according to this embodiment is provided with an attachment portion 201. The receiving portion 202 and the attachment portion 201 form the supply portion 200.

[0071] The discharge tray 14 provided in the housing 72 of the image forming apparatus 1A is an openable / closable member configured to be movable between a cover position (FIG. 8(a)) that covers the receiving portion 202 and the mounting portion 201, and an exposed position (FIG. 8(c)) that exposes the receiving portion 202 and the mounting portion 201. By moving the discharge tray 14 to the exposed position, the receiving portion 202 and the mounting portion 201 are exposed, and a supply pack 210 can be attached to the receiving portion 202 and the mounting portion 201.

[0072] The supply pack 210 contains toner. By attaching the supply pack 210 to the receiving portion 202 and the attachment portion 201 and operating the lever 201a of the attachment portion 201, the shutter of the supply pack 210 opens and the toner is replenished from the supply pack 210 to the storage portion 18.

[0073] The operation of the developing unit 230A when opening and closing the discharge tray 14 for toner replenishment will be described with reference to FIG.

[0074] A support unit 250 is provided inside the housing 72 of the image forming apparatus 1A according to this embodiment. The supply pack 210 is received in the receiving portion 202. At this time, a force for attaching the supply pack 210 acts on the receiving portion 202 of the developing unit 230A. Therefore, by supporting the developing unit 230A with the support unit 250 when attaching the supply pack 210, movement of the developing unit 230A can be suppressed.

[0075] When the supply pack 210 is attached to the supply section 200, the discharge tray 14 is opened. In conjunction with the opening operation of the discharge tray 14, the developing unit 230A is supported by the support unit 250. As a result, the posture of the developing unit 230A can be stabilized when the supply pack 210 is attached.

[0076] The support unit 250 includes a tray gear (driving member, drive gear) 231, an idler gear (intermediate member) 232, and a support member (moving member) 233. The tray gear 231 and the idler gear 232 function as a connecting portion (connecting member) that connects the discharge tray 14 and the support member 233 so that the discharge tray 14 and the support member 233 move in conjunction with each other.

[0077] The supply pack 210 is attached to the receiving portion 202 from above in the vertical direction. The support member 233 supports the receiving portion 202 from below in the vertical direction. The support member 233 is positioned below the receiving portion 202 in the vertical direction, and includes a first cam portion 233a as a support portion that supports the developing unit 230A, and a gear portion 233c that meshes with the idler gear 232.

[0078] The tray gear 231 is fixed to the discharge tray 14 and rotates in conjunction with the opening and closing of the discharge tray 14. The tray gear 231 is engaged with a shaft provided at the rotation center of the discharge tray 14. The support member 233 is connected to the tray gear 231 via an idler gear 232. The support member 233 is configured to be movable between a support position where the first cam portion 233a contacts the developing unit 230A and supports the developing unit 230A, and a retracted position where the support member 233 is retracted from the support position. The support member 233 moves between the support position and the retracted position in conjunction with the movement of the discharge tray 14. A state in which the support member 233 is in the support position is referred to as a support state of the support member 233 and the support unit 250. A state in which the support member 233 is in the retracted position is referred to as a retracted state of the support member 233 and the support unit 250.

[0079] When the discharge tray 14 is positioned at the exposed position, the support member 233 and the support unit 250 are in the supporting state, and the support member 233 is positioned at the supporting position. When the discharge tray 14 is positioned at the covered position, the support member 233 and the support unit 250 are in the retracted state, and the support member 233 is positioned at the retracted position.

[0080] The developing unit 230A is configured to be rotatable about an axis DR that extends in the rotation axis direction relative to the photosensitive unit 300. As the developing unit 230A rotates about the axis DR, the developing unit 230A moves between a contact position and a separation position. When the developing unit 230 moves in the DC direction, the developing roller 12 moves closer to the photosensitive drum 11. When the developing unit 230 moves in the DS direction, the developing roller 12 moves away from the photosensitive drum 11.

[0081] When the support member 233 is in the support position, the support member 233 can support the developing unit 230A. In this state, the developing unit 230A is in the separated position, and the developing roller 12 is separated from the photosensitive drum 11.

[0082] When the support member 233 is in the retracted position, the first cam portion 233a of the support member 233 is separated from the developing unit 230A. Also, the developing roller 12 is in a position where it can develop the electrostatic latent image formed on the photosensitive drum 11 (a position where the developing roller 12 abuts against the photosensitive drum 11). In other words, the developing unit 230A is in the abutment position.

[0083] Control unit 199 of image forming apparatus 1A allows the image forming operation to be performed with support member 233 positioned at the retracted position. Control unit 199 restricts the image forming operation from being performed with support member 233 positioned at the support position.

[0084] In other words, the control unit 199 allows the image forming operation to be performed with the discharge tray 14 positioned at the cover position, and restricts the image forming operation to be performed with the discharge tray 14 positioned at the exposed position.

[0085] Image forming apparatus 1A includes an open / close sensor (output unit, detection unit) 239 configured to output a signal corresponding to the position of at least one of support member 233 or discharge tray 14. Because discharge tray 14 and support member 233 are interlocked, open / close sensor 239 can be said to output a signal corresponding to the position of support member 233, or can be said to output a signal corresponding to the position of discharge tray 14. Therefore, by detecting the position of either discharge tray 14 or support member 233 using open / close sensor 239, it is possible to detect the position of the other of discharge tray 14 or support member 233. In this embodiment, control unit 199 is configured to allow or restrict the execution of the image forming operation based on the output (signal) of open / close sensor 239.

[0086] The receiving section 202 is provided with a supported portion 202f. As described above, when the discharge tray 14 is closed, the first cam portion 233a of the support member 233 is separated from the supported portion 202f of the developing unit 230A (see FIG. 8(a)). At this time, the developing unit 230A is in a unit abutment position where the developing roller 12 abuts against the photosensitive drum 11. Because the first cam portion 233a is separated from the supported portion 202f, the photosensitive drum 11 and the developing roller 12 can stably abut against each other, and the developing roller 12 is in a state where it can develop an electrostatic latent image.

[0087] 8(a), when the discharge tray 14 is in the cover position and the support member 233 is in the retracted position, the open / close sensor 239 and the second cam portion 233b are separated. At this time, the signal state of the open / close sensor 239 is in the OFF state (first state). At this time, the control unit 199 allows the image forming operation to be performed.

[0088] As shown in FIG. 8(c), when the discharge tray 14 is in the exposed position and the support member 233 is in the support position, the open / close sensor 239 comes into contact with the second cam portion 233b. At this time, the signal state of the open / close sensor 239 is ON (second state). The second state is a state different from the first state. At this time, the control unit 199 restricts the image forming operation from being performed. In other words, the control unit 199 can control the image forming apparatus 1A so that the image forming apparatus 1 does not start the image forming operation when the open / close sensor 239 is ON.

[0089] When the discharge tray 14 is open (when the discharge tray 14 is in the exposed position), the support member 233 is in the support position, and the developing unit 230A is in the unit retracted position retracted from the unit abutment position. At this time, the developing roller 12 is separated from the photosensitive drum 11. At this time, the receiving portion 202 engages with the attachment portion 201, and the user can attach the resupply pack 210 to the resupply portion 200 and replenish toner.

[0090] When a user attaches the supply pack 210 to the receiving section 202, the developing unit 230A receives a force in a direction DC in which the developing roller 12 approaches the photosensitive drum 11. At this time, by supporting the developing unit 230A with the support member 233, the posture of the developing unit 230A is stabilized, and the supply pack 210 can be stably attached. Furthermore, when attaching the supply pack 210, the developing roller 12 can be prevented from being pressed against the photosensitive drum 11.

[0091] 9 is a top view of the image forming apparatus 1A of this embodiment. The connector 131, the connector 152, and the connection member 141 according to this embodiment are disposed closer to the center of the housing 72 (the center of the image forming apparatus 1A) than in the first embodiment.

[0092] In this embodiment as well, the length of the connection member 141 is longer than D1 and D2. Also in this embodiment as well, D2 is longer than D1.

[0093] 9, the connection member 141 in this embodiment is disposed near the irradiation area of ​​the laser emitted from the scanner unit 50. Therefore, if the connection member 141 has an excessive length, it will interfere with the laser irradiation.

[0094] Therefore, in this embodiment, a flexible flat cable with mobility is used for the connecting member 141. Specifically, when force is applied to the connecting member 141 as the developing unit 230A moves, the connecting member 141 deforms, thereby suppressing the generation of repulsive force.

[0095] The arrangement of the connection members 141 will be described in more detail with reference to Fig. 10. Fig. 10 is a diagram illustrating the arrangement of the connection members 141 according to this embodiment.

[0096] The direction from connector 131 toward connector 152 along the surface of connection member 141 is defined as the length direction of connection member 141. Figure 10 is a cross-sectional view of connection member 141 in a direction perpendicular to the length direction. In the direction perpendicular to the length direction, width W of connection member 141 is greater than thickness t of connection member 141.

[0097] As described above, the developing unit 230A is rotatable about the axis DR that extends in the rotation axis direction, which is parallel to the longitudinal direction LD.

[0098] By arranging the direction of the width W (width direction) of the connecting member 141 and the rotation axis direction of the axis line DR parallel to each other, the connecting member 141 is easily deformed when the developing unit 230A rotates. Therefore, the repulsive force received from the connecting member 141 when the developing unit 230A rotates can be kept low.

[0099] Furthermore, by making the width direction of the connecting member 141 parallel to the longitudinal direction LD, movement in the longitudinal direction when the connecting member 141 is deformed is suppressed, and therefore, overlap between the connecting member 141 and the laser irradiation area can be suppressed.

[0100] From the above viewpoint, it is preferable that the angle θ formed by the width direction of the connecting member 141, the rotation axis direction of the axis line DR, and the longitudinal direction LD is small. Note that the angle θ here refers to the narrower of the angles formed between the width direction of the connecting member 141, the rotation axis direction of the axis line DR, and the longitudinal direction LD. The magnitude of the angle θ is preferably 45° or less. Regarding the magnitude of this angle θ, even if the developing unit 230A does not have a receiving portion 202, it is preferable that the magnitude of the angle θ be the magnitude shown here.

[0101] As described above, according to the configuration of this embodiment, by attaching the detection unit 150 to the developing unit 230A, even when the developing unit 230 moves between the contact position and the separation position, it is possible to prevent misalignment of the light-emitting unit 51a, the light-receiving unit 51b, and the developing unit 230. Furthermore, since the connecting member 141 has a sufficient length, it is possible to prevent the connecting member 141 from interfering with the contact and separation operation of the developing unit 230A.

[0102] Furthermore, because the length of connecting member 141 is longer than D1 and D2, the electrical connection between connector 131 and connector 152 is maintained both when developing unit 230 is in the contact position and when it is in the separated position. Therefore, controller 199 can detect the remaining toner amount both when developing unit 230 is in the contact position and when it is in the separated position. In other words, it is possible to detect the amount of toner in storage unit 18 while toner is being replenished from replenishment pack 210. As a result, image forming apparatus 1A can display information related to toner replenishment from replenishment pack 210 to the user and execute control related to toner replenishment from replenishment pack 210. [Explanation of symbols]

[0103] 11 Photosensitive drum 12 Developing roller 18 Storage section 51a Light-emitting member 51b Light receiving member 131 Connector 141 Connecting member 152 Connector 230, 230A developing unit 300 drum unit

Claims

1. An image forming apparatus for forming an image on a recording material, A housing including a first connection portion; a drum unit having a photosensitive drum and housed in the housing; a developing unit that is accommodated in the housing and has a container that accommodates toner and a developing roller that supplies the toner to the photosensitive drum, the developing unit being configured to be movable between a first position and a second position relative to the drum unit; a light-emitting element attached to the developing unit; a light receiving element attached to the developing unit, the light receiving element being configured to receive light emitted from the light emitting element and passing through the container; a second connection portion attached to the developing unit, the second connection portion being electrically connected to the light emitting element and the light receiving element; a connection member connected to the first connection portion and the second connection portion such that the first connection portion and the second connection portion are electrically connected to each other; having When the developing unit moves between the first position and the second position, the second connection portion is displaced relative to the first connection portion, An image forming apparatus characterized in that the length of the connection member is longer than a first distance from the first connection portion to the second connection portion when the developing unit is in the first position, and a second distance from the first connection portion to the second connection portion when the developing unit is in the second position.

2. a first substrate to which the first connection portion is attached; a second substrate to which the light emitting element, the light receiving element, and the second connection portion are attached; and When the developing unit is in at least one of the first position or the second position, 2. The image forming apparatus according to claim 1, wherein the first substrate and the second substrate face each other.

3. 3. The image forming apparatus according to claim 1, wherein the connecting member is flexible.

4. The image forming apparatus according to claim 3, characterized in that, when the direction from the first connection portion toward the second connection portion along the surface of the connecting member is defined as the longitudinal direction of the connecting member, the width of the connecting member in a direction perpendicular to the longitudinal direction is larger than the thickness of the connecting member.

5. the developing unit is configured to be rotatable about an axis extending in a rotation axis direction with respect to the drum unit, 5. The image forming apparatus according to claim 4, wherein an angle between the width direction of the connecting member and the direction of the rotation axis is 45[deg.] or less.

6. the developing unit has a receiving portion to which a replenishing container for replenishing the toner to the containing portion is removably attached, the housing has an opening / closing member that is movable between a cover position that covers the receiving portion and an exposed position that exposes the receiving portion, and a support member that is configured to be movable between a support position that supports the developing unit and a retracted position retracted from the support position in conjunction with movement of the opening / closing member, 6. An image forming apparatus according to claim 1, wherein when the opening / closing member is positioned at the exposed position, the support member is positioned at the support position, and when the opening / closing member is positioned at the covered position, the support member is positioned at the retracted position.

7. 7. The image forming apparatus according to claim 1, wherein the first distance is longer than the second distance.

8. 8. The image forming apparatus according to claim 1, further comprising a control unit that performs a detection operation to detect an amount of the toner contained in the container based on a signal output from the light receiving element.

9. 9. The image forming apparatus according to claim 8, wherein the control unit is configured to perform the detection operation both when the developing unit is in the first position and when the developing unit is in the second position.

10. An image forming apparatus as described in any one of claims 1 to 9, characterized in that the first position is a contact position in which the developing roller abuts the photosensitive drum, and the second position is a separation position in which the developing roller is separated from the photosensitive drum.

Images