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 Art

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

[0003] Patent Document 1 discloses a configuration in which a developing unit including a toner container for storing toner and a developing roller is movable such that the developing roller contacts and separates from a photosensitive drum. Further, Patent Document 1 discloses a configuration in which light is irradiated from a light emitting element of the apparatus main body to the toner container in order to detect the amount of toner stored in the toner container, and the light passing through the toner container is received by a light receiving element.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the image forming apparatus of Patent Document 1, since the light emitting element and the light receiving element are arranged in the apparatus main body and are not fixed to the developing unit, the positions of the light emitting element and the light receiving element with respect to the developing unit may vary.

[0006] One object of the present invention is to suppress variations in the positions of a light emitting element and a light receiving element with respect to a developing unit in an image forming apparatus having a movably configured developing unit.

Means for Solving the Problems

[0007] One of the inventions related to this application is as follows:

[0008] An image forming apparatus for forming an image on a recording material, A housing equipped with a first connection section, A drum unit having a photosensitive drum and housed in the aforementioned housing, A substrate having a light-emitting element and a light-receiving element, A developing unit housed in a housing, comprising: a toner storage section for storing toner; a developing roller for supplying the toner to the photosensitive drum; a light guide section for guiding light emitted from the light-emitting element to the storage section and guiding the light that has passed through the storage section to the light-receiving element; and a developing frame having a substrate holding section for holding the substrate, wherein the developing unit is configured to be movable between a first position and a second position relative to the drum unit, A second connection portion attached to the substrate, the second connection portion being electrically connected to the light-emitting element and the light-receiving element, A connecting member is connected to the first connecting portion and the second connecting portion so that the first connecting portion and the second connecting portion are electrically connected, It has, When the developing unit moves between the first and second positions, the second connecting portion is displaced relative to the first connecting portion. The length of the connecting member is longer than the first distance from the first connecting portion to the second connecting portion when the developing unit is in the first position, and the second distance from the first connecting portion to the second connecting portion when the developing unit is in the second position. The developing unit has a receiving section into which a toner supply container for supplying toner is detachably attached. The housing includes an opening / closing member that is movable between a cover position that covers the receiving portion and an exposed position in which the receiving portion is exposed, and a support member configured to be movable between a support position that supports the developing unit so that the developing unit is positioned in the second position, and a retracted position that is moved away from the support position so that the developing unit is positioned in the first position, in conjunction with the movement of the opening / closing member. An image forming apparatus characterized in that when the opening / closing member is positioned in the exposed position, the support member is positioned in the support position, and when the opening / closing member is positioned in the cover position, the support member is positioned in the retracted 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 drawing]

[0010] [Figure 1] This is a perspective view of an image forming apparatus. [Figure 2] This is a diagram illustrating the internal configuration of an image forming apparatus. [Figure 3] This is a diagram illustrating the internal configuration of an image forming apparatus. [Figure 4] This is a top view of an image forming apparatus. [Figure 5] (a) A perspective view showing the process unit. (b) A perspective view showing the wiring board and substrate holding member. (c) A perspective view showing the process unit with the wiring board and substrate holding member attached. [Figure 6] (a) Cross-sectional view of the process unit. (b) Cross-sectional view of the process unit. [Figure 7]It is a circuit diagram showing a toner remaining detection sensor. [Figure 8] (a) It is a diagram showing a support unit in a retracted state. (b) It is a diagram showing a support unit in a support start state. (c) It is a diagram showing a support unit in a supported state. [Figure 9] Top view of the image forming apparatus according to Example 2. [Figure 10] Diagram for explaining the arrangement of the connection members according to Example 2.

Mode for Carrying Out the Invention

[0011] Hereinafter, with reference to the drawings, the mode for carrying out this invention will be exemplarily and specifically described based on examples. However, dimensions, materials, shapes, relative arrangements, etc. of the components described in this embodiment of implementation should be appropriately changed according to the configuration of the apparatus to which the invention is applied and various conditions. That is, it is not intended to limit the scope of this invention to the following embodiments of implementation. Also, in the drawings used in the following description, for the sake of explanation, parts or parts of parts may be omitted or shown in a simplified manner.

Examples

[0012] <Overall Configuration of the Image Forming Apparatus> Using FIGS. 1 and 2, the overall configuration of the image forming apparatus 1 in this embodiment will be described. The image forming apparatus 1 in this embodiment is a monochrome laser beam printer using an electrophotographic process. The image forming apparatus 1 is capable of executing an image forming operation of forming an image with a developer (toner) on a recording material P according to image information transmitted from an external device such as a personal computer. Examples of the recording material P include recording paper, label paper, OHP sheets, cloth, etc.

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

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

[0015] In Figure 1, the image forming apparatus 1 has a feeding tray 4 in which recording material P is contained, and an output tray (opening / closing member) 14 on which the discharged recording material P is stacked. The feeding tray 4 can be pulled out in the Y direction, allowing the user to replenish the recording material P. The recording material P that is fed from the feeding tray 4 and on which an image has been formed is discharged from the output port 15 in the output direction shown in Figure 1 and stacked on the output tray 14. In this embodiment, the output 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) of the image forming apparatus 1 on the downstream side in the discharge direction, covering the control board 100. An outer cover 71 is provided on a portion of the front other than where the front cover 70 is located, as well as on the sides and top of the image forming apparatus 1. The front cover 70, the outer cover 71, and the discharge tray 14 described above all form the housing (device body, main body frame) 72 of the image forming apparatus 1. Here, the housing 72 is a component that covers the entire image forming apparatus 1 and houses the scanner unit 50, process unit 500, etc., which will be described later, inside. The discharge port 15 described above is an opening formed in a part 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 loaded onto the upper part (loading part) provided on the discharge tray 14.

[0017] The image forming apparatus 1 comprises 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 comprises a photosensitive drum 11 and a charging roller (charging member) 17. The developing unit 230 comprises a toner storage section 18 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 develops the electrostatic latent image formed on the photosensitive drum 11 by supplying toner to the photosensitive drum 11. In this embodiment, as shown in Figure 2, the developing roller 12 develops the electrostatic latent image while in contact with the photosensitive drum 11.

[0018] As described above, the housing 72 houses the process unit 500 (photosensitive unit 300 and developing unit 230) and is equipped with an output tray 14. The output tray 14 is attached to the outer cover 71.

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

[0020] The scanner unit 50 irradiates the photosensitive drum 11 with laser light based on the input image information. The scanner unit 50 comprises a laser oscillator that outputs laser light, a polygon mirror and lens for irradiating the photosensitive drum 11 with laser light, 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 when laser light is shone on it, an electrostatic latent image is formed on the photosensitive drum 11. Then, the toner stored in the storage unit 18 is transported to the photosensitive drum 11 by the developing roller 12, which develops this electrostatic latent image and forms a toner image on the photosensitive drum 11.

[0022] In parallel with the image forming process described above, recording material P is fed from the feeding tray 4. A pickup roller 3, a feeding roller 5a, and a pair of transport rollers 5c are provided on the transport path of the image forming apparatus 1. The pickup roller 3 contacts the uppermost recording material P contained in the feeding tray 4, and the roller itself rotates to feed the recording material P. The feeding roller 5a and the separation roller 5b that presses against it form a separation nip. If multiple recording materials P are fed into the separation nip due to the frictional force between the recording materials P, the feeding roller 5a and the separation roller 5b separate the multiple recording materials P and feed only the uppermost one downstream.

[0023] The recording material P fed from the feeding tray 4 is transported toward the transfer roller 7 by the transport roller pair 5c. When a transfer bias is applied to the transfer roller 7, the toner image formed on the photosensitive drum 11 is transferred to 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 the fixing device 9, fixing the toner image to the recording material P. The fixing device 9 consists of a heating roller 9a with a built-in fixing heater and a pressurizing roller 9b that is biased toward the heating roller 9a. The recording material P with the fixed toner image is then discharged to the discharge tray 14 by the discharge roller pair 10.

[0024] When forming an image on both sides of the recording material P, the discharge roller pair 10 guides the recording material P to the double-sided transport path 16 by switching back the recording material P on which the image has been formed on the first side. The recording material P guided to the double-sided transport path 16 is transported again toward the transfer roller 7 by the double-sided transport roller pair 5d and the transport roller pair 5c. After the transfer roller 7 forms an image on the second side, which is the reverse side of the first side, the recording material P is discharged to the discharge tray 14 by the discharge roller pair 10. After the toner image has been transferred to the recording material P, any toner remaining on the photosensitive drum 11 is cleaned by the cleaning unit 13.

[0025] The enclosure 72 has a control board 100. The control board 100 includes a wiring board (first board, first board section, first printed circuit board) 101, a control unit (CPU, arithmetic unit) 199, and a connector (first connection section, main body side connection section) 131. The control unit 199 and the connector 131 are soldered to the wiring board 101, and the control unit 199 and the connector 131 are electrically connected.

[0026] A detection unit 150 is attached to the developing unit 230. The detection unit 150 includes a wiring board (second circuit board, second circuit board section, second printed circuit board) 151, a connector (second connection section, unit-side connection section) 152, and a toner level sensor 51, which will be described later. The connector 152 and the toner level sensor 51 (light-emitting section 51a and light-receiving section 51b, which will be described later) are attached to the wiring board 151 by solder, and the connector 152 and the toner level 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 Figure 2, the control board 100 is positioned such that the surface of the wiring board 101 intersects with the discharge direction. Furthermore, in the discharge direction, the wiring board 101 is located between the front cover 70 and the scanner unit 50. In this embodiment, the detection unit 150 and the control board 100 are positioned opposite each other, but they may be positioned in non-opposing locations.

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

[0029] As the connecting member 141, it is preferable to use an electric wire having a conductor covered with an insulating layer. As the connecting member 141, multiple electric wires, a cable made by bundling multiple electric wires together, or a harness with connector members attached to both ends of multiple electric wires can be used. Furthermore, a so-called flexible flat cable can also be used as the connecting member 141.

[0030] <Contact and separation movement of the developing roller> The contact and separation operation of the developing roller 12 with respect to the photosensitive drum 11 will be explained using Figures 2 and 3. Figure 3 is a diagram illustrating the internal configuration of the image forming apparatus 1 as seen 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 is movable between a contact position where the developing roller 12 is in contact with the photosensitive drum 11 (Figure 2) and a separated position where the developing roller 12 is separated from the photosensitive drum 11 (Figure 3).

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

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

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

[0035] <Scanner's coverage area> Figure 4 is a top view of the image forming apparatus 1 with the outer cover 71 removed. The housing 72 has side walls 73 and 74. The connecting member 141 is positioned to avoid the irradiation area of ​​the laser emitted from the scanner unit 50 (the grid-like hatched area in Figure 4). Specifically, with respect to the rotation axis direction of the photosensitive drum 11, the connecting member 141 is located outside the irradiation area of ​​the laser emitted from the scanner unit 50.

[0036] <Process Unit Configuration> The process unit 500 will be described using 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 process unit 500 with the wiring board 151 and the substrate holding member 710 attached. 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 in Figure 6(a).

[0037] As shown in Figure 5(a), the developing unit 230 of the process unit 500 includes 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 toner storage section 18 (see Figures 2 and 3) for storing toner. The developing roller 12 is supported by the frame 340.

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

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

[0040] In this embodiment, as shown in Figure 5(c), the wiring board 151 and the substrate holding member 710 are assembled to the developing lid 321. The substrate holding member 710 is assembled to the developing lid 321 while being sandwiched between the developing lid 321 and the wiring board 151.

[0041] The developing unit 230 is fitted with 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 housing unit 18 via the light guide 610, and a detection unit 150 having 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 Figure 5(b), a light-emitting unit 51a, a light-receiving unit 51b, and a connector 152 are attached to the wiring board 151. In this embodiment, an LED is used for the light-emitting unit 51a, and a phototransistor that turns on when light from the LED is used for the light-receiving unit 51b, but the embodiment is not limited to these. For example, a halogen lamp or fluorescent lamp may be used for the light-emitting unit 51a, and a photodiode or avalanche photodiode may be used for the light-receiving unit 51b. A connecting member 141 is connected to the connector 152. As a result, the light-emitting unit 51a and the light-receiving unit 51b are electrically connected 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 the signal output from the light-receiving unit 51b can be transmitted to the control board 100.

[0043] Furthermore, the wiring board 151 has positioning holes 151a and 151b through which the substrate positioning parts 321a and 321b are inserted and engage, and substrate fixing holes 700c and 700d through which screws that are fixed to the substrate fixing parts 321c and 321d can pass.

[0044] Similarly, the substrate holding member 710 has positioning holes 710a and 710b through which the substrate positioning parts 321a and 321b are inserted and engage, and substrate fixing holes 710c and 710d through which screws that fix the substrate to the substrate fixing parts 321c and 321d can pass. Furthermore, the substrate holding member 710 has a first hole 711a into which the first guide part 610a of the optical guide 610 is inserted, and a second hole 711b into which the second guide part 610b of the optical guide 610 is inserted. These first hole 711a and second hole 711b have a cylindrical shape. The substrate holding member 710, as a holder, holds the wiring board 151.

[0045] The substrate holding member 710 is positioned relative to the developing lid 321 by the substrate positioning 321a and 321b of the developing lid 321 penetrating and engaging with the positioning holes 710a and 710b. Similarly, the wiring board 151 is positioned relative to the developing lid 321 by the substrate positioning 321a and 321b of the developing lid 321 penetrating and engaging with the positioning holes 151a and 151b. In this way, by using the substrate positioning 321a and 321b in common for positioning the substrate holding member 710 and the wiring board 151, the developing lid 321, the substrate holding member 710, and the wiring board 151 can be positioned with higher precision.

[0046] Furthermore, with the substrate holding member 710 and the wiring board 151 positioned relative to the developing 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 lid 321. As a result, the substrate holding member 710 and the wiring board 151 are fixed to the developing lid 321 by a single screw, and the substrate holding member 710 and the wiring board 151 are fixed to the developing lid 321.

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

[0048] As described above, since the substrate holding member 710 and the wiring board 151 are precisely positioned on the developing lid 321, the light emitted from the light-emitting unit 51a is reliably guided by the first guide unit 610a. The light guided by the first guide unit 610a into the housing unit (housing chamber) 18 inside the frame 340 is then emitted from the first guide unit 610a toward the longitudinal LD.

[0049] Then, the light traveling along the optical path Q1 inside the housing section 18 is guided to the outside of the frame 340 by the second guide section 610b. Since the second guide section 610b is positioned close to the light receiving section 51b, the light emitted from the second guide section 610b is reliably received by the light receiving section 51b. Therefore, the accuracy of toner level detection by the light emitting section 51a and the light receiving section 51b can be improved.

[0050] Here, the arrangement of the light-emitting unit 51a and the light-receiving unit 51b will be explained in more detail. In the frame 340, the light-emitting unit 51a and the light-receiving unit 51b are located at the end opposite to the end where the developing roller 12 is located. Furthermore, the light-emitting unit 51a and the light-receiving unit 51b are located in the central part of the housing unit 18 in the longitudinal LD ​​direction. By locating the light-emitting unit 51a and the light-receiving unit 51b in the central part of the housing unit 18, the remaining amount of toner in the housing unit 18 can be detected accurately. That is, while the developer (toner) may be unevenly distributed at the ends of the housing unit 18 in the longitudinal LD ​​direction, the central part of the housing unit 18 has less uneven distribution of the developer, so the actual remaining amount of toner can be detected.

[0051] When the developing unit 230 moves between the contact position and the separation position, the frame 340 also moves. Since 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 separation 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 when the developing unit 230 moves between the contact position and the separation position, the connector 152 is displaced relative to the connector 131.

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

[0053] Figure 7 is a circuit diagram showing an example of the circuit configuration of the toner level sensor 51 mounted on the detection unit 150. The toner level 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 unit 51a is connected to a power supply voltage Vcc and a current-limiting resistor R1, and the light-emitting unit 51a emits light according to the current determined by the current-limiting resistor R1. The light emitted from the light-emitting unit 51a passes through an optical path Q1 (not shown) and is received by the light-receiving unit 51b. The power supply voltage Vcc is connected to the collector terminal of the light-receiving unit 51b, and a detection resistor R2 is connected to the emitter terminal. The light-receiving unit 51b, which is a phototransistor, receives the light emitted from the light-emitting unit 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 of the control board 100. In other words, the light-receiving unit 51b changes its output value according to the amount of toner (developer) stored in the storage unit 18.

[0055] As described above, mounting the toner level sensor 51 of the detection unit 150 on the developing unit 230 makes it possible to shorten the distance of the optical path Q1 compared to when the toner level detection sensor 51 is mounted on the housing 72. Compared to the configuration in which the toner level sensor 51 is mounted on the housing 72, it is possible to improve the positional accuracy of the light-emitting unit 51a and the light-receiving unit 51b with respect to the optical path Q1. In other words, the variation when the light emitted from the light-emitting unit 51a is received by the light-receiving unit 51b is reduced, thus 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 stirring member 34 (see Figure 6(a)) housed in the storage unit 18 rotates and the toner is stirred for a certain period of time, the control unit 199 can calculate the amount of toner in the storage unit 18 based on the length of time the light receiving unit 51b detected the light and the intensity of the light.

[0057] <Length of connecting member> As described above, when the developing unit 230 moves from the contact position to 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 change. 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. Thus, 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] As shown in Figures 2 and 3, when the developing unit 230 is in contact 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 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 hinder the movement of the developing unit 230. Furthermore, it is preferable that the connecting member 141 is flexible.

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

[0060] Furthermore, in this embodiment, D1 is longer than D2. In other words, the length of the connecting member 141 is longer than D1.

[0061] As described above, when the developing unit 230 moves, the detection unit 150 also moves in conjunction. At this time, a repulsive force acts on the connector 152 of the detection unit 150, causing the connecting member 141 to try to return to its original position, and a force is applied in the opposite direction to the direction of movement of the developing unit 230. 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-to-separation movement of the developing unit 230 is inhibited.

[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 hinder the movement of the developing unit 230. In other words, the length of the connecting member 141 should be greater than or equal to D1 and D2.

[0063] Furthermore, it is preferable that the length of the connecting member 141 has an additional length beyond whichever of D1 and D2 is longer. In this embodiment, the length of the connecting member 141 is set such that the difference between the connecting member 141 and D1 is greater than the difference between D1 and D2. Also, because the connecting member 141 has an additional length, a part of the connecting member 141 may be bent and attached to the connector 152 and the connector 131. In this case, by positioning the bent portion of the connecting member 141 closer to the connector 152 than to the connector 131, the effect of the repulsive force of the connecting member 141 generated when the developing unit 230 moves on the connector 152 can be minimized. In other words, it is preferable that the bent portion of the connecting member 141 is positioned such 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 if the developing unit 230 moves between a contact position and a separated position, misalignment of the light-emitting unit 51a, the light-receiving unit 51b, and the developing unit 230 can be prevented. Furthermore, since the connecting member 141 has sufficient length, obstruction of the contact and separation movement of the developing unit 230 by the connecting member 141 is suppressed.

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

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

[0067] In Example 2, we will describe an image forming apparatus 1A and a developing unit 230A, which have some configurations different from the image forming apparatus 1 of Example 1. Configurations similar to those described in Example 1 may be omitted from description, not shown, or described using the same reference numerals in the figures.

[0068] The image forming apparatus 1A according to this embodiment has a developing unit 230A. As will be described later, in addition to the configuration of the developing apparatus 230 according to Embodiment 1, the developing unit 230A has a receiving section 202 into which a replenishment pack (replenishment container) 210 for replenishing toner in the storage section 18 is detachably attached. Similar to Embodiment 1, the developing unit 230A is also equipped with a detection section 150. The image forming apparatus 1A according to this embodiment will be described below with reference to Figures 8 and 9.

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

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

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

[0072] The replenishment pack 210 contains toner. By attaching the replenishment pack 210 to the receiving section 202 and the mounting section 201, and operating the lever 201a on the mounting section 201, the shutter of the replenishment pack 210 is opened, and toner is replenished from the replenishment pack 210 to the storage section 18.

[0073] Using Figure 8, the operation of the developing unit 230A when opening and closing the output tray 14 for toner replenishment will be explained.

[0074] The housing 72 of the image forming apparatus 1A according to this embodiment is equipped with a support unit 250. The replenishment pack 210 is received by the receiving section 202. At this time, the receiving section 202 of the developing unit 230A is subjected to the force required to attach the replenishment pack 210. Therefore, when attaching the replenishment pack 210, the development unit 230A can be supported by the support unit 250, thereby suppressing the movement of the developing unit 230A.

[0075] When attaching the replenishment pack 210 to the replenishment unit 200, the discharge tray 14 is opened. In conjunction with the opening 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 attaching the replenishment pack 210.

[0076] The support unit 250 includes a tray gear (drive member, drive gear) 231, an idler gear (intermediate member) 232, and a support member (movable member) 233. The tray gear 231 and idler gear 232 function as connecting parts (connecting members) that link the discharge tray 14 and the support member 233 so that the discharge tray 14 and the support member 233 move in conjunction.

[0077] A replenishment pack 210 is attached to the receiving section 202 from above in the vertical direction. The support member 233 supports the receiving section 202 from below in the vertical direction. The support member 233 is located below the receiving section 202 in the vertical direction and includes a first cam section 233a as a support section for the developing unit 230A, and a gear section 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 pivot point 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 in which the first cam portion 233a contacts and supports the developing unit 230A, and a retracted position in which it 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. The state in which the support member 233 is in the support position is called the support state of the support member 233 and the support unit 250. The state in which the support member 233 is in the retracted position is called the retracted state of the support member 233 and the support unit 250.

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

[0080] The developing unit 230A is configured to rotate around an axis DR that extends in the direction of the rotation axis relative to the photosensitive unit 300. By rotating the developing unit 230A around axis DR, the developing unit 230A moves between a contact position and a separated position. When the developing unit 230 moves in the DC direction, the developing roller 12 approaches 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 a separated position, and the developing roller 12 is away 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 away 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 (the position where the developing roller 12 is in contact with the photosensitive drum 11). In other words, the developing unit 230A is in the contact position.

[0083] The control unit 199 of the image forming apparatus 1A allows the image forming operation to be performed when the support member 233 is in the retracted position. The control unit 199 restricts the image forming operation from being performed when the support member 233 is in the supported position.

[0084] In other words, the control unit 199 allows the image forming operation to be performed when the output tray 14 is in the cover position. The control unit 199 restricts the image forming operation from being performed when the output tray 14 is in the exposed position.

[0085] The 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 the support member 233 or the discharge tray 14. Since the discharge tray 14 and the support member 233 are interlocked, the open / close sensor 239 can output a signal corresponding to the position of the support member 233, or it can output a signal corresponding to the position of the discharge tray 14. Therefore, by detecting the position of either the discharge tray 14 or the support member 233 using the open / close sensor 239, the position of the other of the discharge tray 14 or the support member 233 can be detected. In this embodiment, the control unit 199 is configured to allow or restrict the execution of the image forming operation based on the output (signal) of the open / close sensor 239.

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

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

[0088] As shown in Figure 8(c), when the discharge tray 14 is in the exposed position and the support member 233 is in the support position, the opening / closing sensor 239 contacts the second cam portion 233b. At this time, the signal state of the opening / closing sensor 239 is ON (second state). The second state is different from the first state. At this time, the control unit 199 restricts the execution of the image forming operation. 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 opening / closing sensor 239 is ON.

[0089] When the output tray 14 is open (when the output tray 14 is in the exposure position), the support member 233 is in the support position, and the developing unit 230A is in the unit retracted position, having moved away from the unit contact position. At this time, the developing roller 12 is separated from the photosensitive drum 11. At this time, the receiving section 202 engages with the mounting section 201, and the user can attach the replenishment pack 210 to the replenishment section 200 to replenish the toner.

[0090] When the user attaches the replenishment pack 210 to the receiving section 202, the developing unit 230A receives a force in the direction DC, which brings the developing roller 12 closer to the photosensitive drum 11. At this time, the developing unit 230A is supported by the support member 233, which stabilizes the posture of the developing unit 230A and allows the replenishment pack 210 to be attached stably. In addition, when attaching the replenishment pack 210, it is possible to suppress the developing roller 12 from being pressed against the photosensitive drum 11.

[0091] Figure 9 is a top view of the image forming apparatus 1A of this embodiment. The connectors 131, 152, and 141 in this embodiment are positioned closer to the center of the housing 72 (the center of the image forming apparatus 1A) than in Embodiment 1.

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

[0093] As shown in Figure 9, the connecting member 141 in this embodiment is positioned near the irradiation area of ​​the laser emitted from the scanner unit 50. Therefore, if the connecting member 141 has an excessive length, it will obstruct the laser irradiation.

[0094] Therefore, in this embodiment, a movable flexible flat cable 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 connecting member 141 will be explained in more detail using Figure 10. Figure 10 is a diagram illustrating the arrangement of the connecting member 141 according to this embodiment.

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

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

[0098] By making the direction of the width W of the connecting member 141 (width direction) parallel to the rotation axis direction of the axis DR, the connecting member 141 is more 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 deforms is suppressed. 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 between the width direction of the connecting member 141, the rotation axis direction of the axis DR, and the longitudinal direction LD be small. Here, the angle θ refers to the narrower of the angles formed between the width direction of the connecting member 141, the rotation axis direction of the axis DR, and the longitudinal direction LD. It is preferable that the size of the angle θ is 45° or less. Regarding the size of this angle θ, even if the developing unit 230A does not have a receiving portion 202, it is preferable that the size of the angle θ be the size indicated here.

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

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

[0103] 11 Photosensitive drum 12 Developing roller 18. Detention Unit 51a Light-emitting member 51b Light receiving member 131 Connector 141 Connecting Member 152 connectors 230, 230A Developing Unit 300 Drum Units

Claims

1. An image forming apparatus for forming an image on a recording material, A housing equipped with a first connection part, A drum unit having a photosensitive drum and housed in the aforementioned housing, A substrate having a light-emitting element and a light-receiving element, A developing unit housed in a housing comprises a toner storage section, a developing roller that supplies the toner to the photosensitive drum, a light guide section that guides light emitted from the light-emitting element to the storage section and the light that has passed through the storage section to the light-receiving element, and a developing frame having a substrate holding section that holds the substrate, wherein the developing unit is configured to be movable between a first position and a second position relative to the drum unit, A second connection portion attached to the substrate, the second connection portion being electrically connected to the light-emitting element and the light-receiving element, A connecting member is connected to the first connecting portion and the second connecting portion so that the first connecting portion and the second connecting portion are electrically connected, It has, When the developing unit moves between the first and second positions, the second connecting portion is displaced relative to the first connecting portion. The length of the connecting member is longer than the first distance from the first connecting portion to the second connecting portion when the developing unit is in the first position, and the second distance from the first connecting portion to the second connecting portion when the developing unit is in the second position. The developing unit has a receiving section into which a toner supply container for supplying toner is detachably attached. The housing includes an opening / closing member that is movable between a cover position that covers the receiving portion and an exposed position in which the receiving portion is exposed, and a support member configured to be movable between a support position that supports the developing unit so that the developing unit is positioned in the second position, and a retracted position that is moved away from the support position so that the developing unit is positioned in the first position, in conjunction with the movement of the opening / closing member. An image forming apparatus characterized in that when the opening / closing member is positioned in the exposed position, the support member is positioned in the support position, and when the opening / closing member is positioned in the cover position, the support member is positioned in the retracted position.

2. The image forming apparatus according to claim 1, characterized in that the substrate is fixed to the substrate holding portion by screws.

3. An image forming apparatus for forming an image on a recording material, A housing equipped with a first connection part, A drum unit having a photosensitive drum and housed in the aforementioned housing, A developing unit housed in the casing, comprising a toner storage section and a developing roller for supplying the toner to the photosensitive drum, wherein the developing unit is 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, configured to receive light emitted from the light-emitting element and passing through the housing, A second connection part attached to the developing unit, the second connection part being electrically connected to the light-emitting element and the light-receiving element, A connecting member is connected to the first connecting portion and the second connecting portion so that the first connecting portion and the second connecting portion are electrically connected, It has, When the developing unit moves between the first and second positions, the second connecting portion is displaced relative to the first connecting portion. The length of the connecting member is longer than the first distance from the first connecting portion to the second connecting portion when the developing unit is in the first position, and the second distance from the first connecting portion to the second connecting portion when the developing unit is in the second position. The developing unit has a receiving section into which a toner supply container for supplying toner is detachably attached. The housing includes an opening / closing member that is movable between a cover position that covers the receiving portion and an exposed position in which the receiving portion is exposed, and a support member configured to be movable between a support position that supports the developing unit so that the developing unit is positioned in the second position, and a retracted position that is moved away from the support position so that the developing unit is positioned in the first position, in conjunction with the movement of the opening / closing member. An image forming apparatus characterized in that when the opening / closing member is positioned in the exposed position, the support member is positioned in the support position, and when the opening / closing member is positioned in the cover position, the support member is positioned in the retracted position.

4. The image forming apparatus according to claim 3, characterized in that the developing unit has a substrate including the light-emitting element and the light-receiving element.

5. The image forming apparatus according to claim 4, characterized in that the substrate is attached to the developing unit by screws.

6. When the aforementioned substrate is defined as a second substrate, the first substrate to which the first connection portion is attached further comprises: When the developing unit is in at least one of the first position or the second position, The image forming apparatus according to any one of claims 1 to 2, 4, and 5, characterized in that the first substrate and the second substrate face each other.

7. The image forming apparatus according to any one of claims 1 to 6, characterized in that the connecting member is flexible.

8. The image forming apparatus according to claim 7, characterized in that, when the direction from the first connecting portion to the second connecting 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 greater than the thickness of the connecting member.

9. The developing unit is configured to be rotatable around an axis extending in the direction of the rotation axis relative to the drum unit. The image forming apparatus according to claim 8, characterized in that the angle between the width direction of the connecting member and the rotation axis direction is 45° or less.

10. The image forming apparatus according to any one of claims 1 to 9, characterized in that the first distance is longer than the second distance.

11. The image forming apparatus according to any one of claims 1 to 10, further comprising a control unit that performs a detection operation to detect the amount of toner contained in the storage unit based on a signal output from the light receiving element.

12. The image forming apparatus according to claim 11, characterized in that 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.

13. The image forming apparatus according to any one of claims 1 to 12, characterized in that the first position is a contact position in which the developing roller contacts the photosensitive drum, and the second position is a separation position in which the developing roller is separated from the photosensitive drum.

Images