Image forming apparatus

Abstract

An image forming apparatus is disclosed. An image forming apparatus includes: (i) a housing including a first connector; (ii) a drum unit; (iii) a developing unit including an accommodation portion accommodating toner and being movable between an abutting position and a separated position; (iv) a detection unit including a light emitting element, a light receiving element, and a second connector electrically connected to the light emitting element and the light receiving element, and being installed on the developing unit; and (v) a connection member connected to the first connector and the second connector to electrically connect the first connector and the second connector to each other. A length of the connection member is longer than a first distance from the first connector to the second connector when the developing unit is located at the abutting position, and is longer than a second distance from the first connector to the second connector when the developing unit is located at the separated position.

Description

Technical Field

[0001] This disclosure relates to an image forming apparatus using an electrophotographic method. Background Technology

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

[0003] Japanese Patent Application Publication No. 2003-295596 discloses a configuration in which a developing unit, including a toner container and a developing roller, can move in a manner that allows the developing roller to contact and separate from the photosensitive drum. Furthermore, Japanese Patent Application Publication No. 2003-295596 also discloses a configuration in which the toner container is irradiated by light from a light-emitting element of the device body, and the light passing through the toner container is received by a light-receiving element to detect the amount of toner contained in the toner container.

[0004] In the image forming apparatus discussed in Japanese Patent Application Publication No. 2003-295596, the light-emitting element and the light-receiving element are deployed on the apparatus body and are not fixed relative to the developing unit, so the positions of the light-emitting element and the light-receiving element relative to the developing unit may change. Summary of the Invention

[0005] This disclosure allows an image forming apparatus including a movably configurable developing unit to prevent changes in the position of the light-emitting element and the light-receiving element relative to the developing unit.

[0006] One aspect of this disclosure is configured as follows.

[0007] An image forming apparatus configured to form an image on a recording material includes: a housing including a first connector; a drum unit including a photosensitive drum and housed within the housing; a developing unit including a toner receiving portion and a developing roller configured to supply toner to the photosensitive drum, and housed within the housing and movable relative to the drum unit between (i) an contact position where the developing roller abuts against the photosensitive drum and (ii) a separation position where the developing roller separates from the photosensitive drum; a light-emitting element mounted on the developing unit; and a light-receiving element mounted on the developing unit and configured to receive light from the light-emitting element. The light emitted and transmitted through the receiving portion; a second connector, which is mounted on the developing unit and electrically connected to the light-emitting element and the light-receiving element; and a connecting member, which is connected to the first connector and the second connector such that the first connector and the second connector are electrically connected to each other, wherein the second connector is displaced relative to the first connector when the developing unit moves between an abutting position and a separating position, and wherein the length of the connecting member is longer than a first distance from the first connector to the second connector when the developing unit is in the abutting position, and longer than a second distance from the first connector to the second connector when the developing unit is in the separating position.

[0008] Other features of this disclosure will become clear from the following description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0009] Figure 1 It is a perspective view of the image forming apparatus.

[0010] Figure 2 The internal configuration of the image forming apparatus is illustrated.

[0011] Figure 3 The internal configuration of the image forming apparatus is illustrated.

[0012] Figure 4 This is a top view of the image forming apparatus.

[0013] Figure 5A This is a perspective view illustrating the processing unit. Figure 5B This is a perspective view illustrating the wiring board and board retaining components. Figure 5C It is a perspective view illustrating a processing unit on which a wiring board and board holding member are mounted.

[0014] Figure 6A This is a cross-sectional view of the processing unit. Figure 6B This is a cross-sectional view of the processing unit.

[0015] Figure 7 This is a circuit diagram illustrating a sensor for detecting residual toner levels.

[0016] Figure 8AThe diagram illustrates a support unit in a retracted state. Figure 8B The diagram illustrates a support unit in the initial support phase. Figure 8C The diagram illustrates a support unit in a supported state.

[0017] Figure 9 This is a top view of the image forming apparatus according to a second exemplary embodiment.

[0018] Figure 10 The illustration shows the layout of the connecting members according to a second exemplary embodiment. Detailed Implementation

[0019] In the following description, configurations for implementing this disclosure will be described in detail with reference to the accompanying drawings and exemplary embodiments thereof. However, the dimensions, materials, shapes, relative arrangements, etc., of the components described in these exemplary embodiments should be appropriately varied depending on the configuration of the apparatus to which this disclosure is applied and various conditions. That is, they are not intended to limit the scope of the invention to the following exemplary embodiments. Furthermore, in the figures used in the following description, components or portions of components may be omitted or simplified for illustrative purposes.

[0020] <Overall Configuration of the Image Forming Apparatus>

[0021] Reference Figure 1 and Figure 2 The overall configuration of the image forming apparatus 1 according to the first exemplary embodiment will be described.

[0022] The image forming apparatus 1 according to this exemplary embodiment is a monochrome laser beam printer using electrophotographic processing. The image forming apparatus 1 can perform an image forming operation by forming an image on a recording material P using a developer (toner) based on image information sent from an external device such as a personal computer. Examples of recording materials P include recording paper, label paper, overhead projector (OHP) sheets, and cloth.

[0023] In the following description, when the image forming apparatus 1 is disposed on a horizontal surface, the Z direction will be defined as the height direction of the image forming apparatus 1 (the direction opposite to the direction of gravity). The X direction will be defined as the direction that intersects the Z direction and extends parallel to the rotation axis direction (main scanning direction) of the photosensitive drum 11 as described below. The Y direction will be defined as the direction that intersects the X and Z directions. Ideally, the X, Y, and Z directions intersect each other perpendicularly. In addition, for convenience, the positive and negative sides in the X direction will be referred to as the right side and left side, respectively. The positive and negative sides in the Y direction will be referred to as the front side or front surface side and the rear side or rear surface side, respectively. The positive and negative sides in the Z direction will be referred to as the upper side and lower side, respectively. In this exemplary embodiment, the Z direction is parallel to the vertical direction, and the X and Y directions are parallel to the horizontal direction.

[0024] Figure 1 The illustration shows a perspective view of the image forming apparatus 1, and Figure 2 The illustration shows the internal configuration of the image forming apparatus 1 when viewed from the X direction (the direction of the rotation axis of the photosensitive drum 11). Figure 2 The main illustrations show the components related to image formation and processing.

[0025] exist Figure 1 In this image forming apparatus 1, there is a feed tray 4 containing recording material P and a discharge tray (opening / closing member) 14 on which discharged recording material P is stacked. The feed tray 4 is configured to be pulled out in the Y direction, and the user can replenish the recording material P therein. The recording material P fed from the feed tray 4 and subjected to image forming is discharged from the discharge port 15 toward... Figure 1 The waste is discharged in the discharge direction shown in the diagram and stacked on the discharge tray 14. In this exemplary embodiment, the discharge direction is parallel to the Y direction.

[0026] A front cover 70 is disposed on a portion of the end face (part of the front surface) of the image forming apparatus 1 on the downstream side in the discharge direction, and covers the control plate 100 thereon. An outer cover 71 is disposed on a portion of the front surface other than the portion where the front cover 70 is disposed, as well as on the side surface and top surface of the image forming apparatus 1. The front cover 70, the outer cover 71, and the discharge tray 14 described above together form the housing (apparatus body or main frame member) 72 of the image forming apparatus 1. The housing 72 is now a member that covers the entire image forming apparatus 1 and includes, for example, the scanner unit 50 and the processing unit 500, which will be described below. The discharge port 15 described above is an opening formed on a portion of the housing 72, and the recording material P is discharged outside the image forming apparatus 1 through this opening. The recording material P discharged from the discharge port 15 is stacked on the upper surface portion (stack portion) provided on the discharge tray 14.

[0027] The image forming apparatus 1 includes a processing unit 500, which includes a photosensitive unit (drum unit) 300 and a developing unit 230. The processing unit 500 is housed in a housing 72. The photosensitive unit 300 includes a photosensitive drum 11 and a charged roller (charged component) 17.

[0028] The developing unit 230 includes a container 18 for holding toner and a developing roller 12. The photosensitive drum 11 is an image carrier member on which an electrostatic latent image is carried. The developing roller 12 is a developing agent carrier member that carries toner as a developing agent. 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 exemplary embodiment, as... Figure 2 As shown in the diagram, the developing roller 12 develops electrostatic latent images while in contact with the photosensitive drum 11.

[0029] As described above, the housing 72 houses the processing unit 500 (photosensitive unit 300 and developing unit 230) and is provided with a discharge tray 14. The discharge tray 14 is attached to the outer cover 71.

[0030] Reference Figure 2 The flow of the image forming operation (image forming process) to be performed on the recording material P is described. When image information is transmitted to the image forming apparatus 1, the photosensitive drum 11, which is a rotating member, is driven to rotate at a predetermined circumferential speed (processing speed) in the direction indicated by arrow R based on the printing start signal.

[0031] The scanner unit 50 uses a laser to irradiate the photosensitive drum 11 based on the input image information. The scanner unit 50 includes 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.

[0032] The photosensitive drum 11 is pre-charged by the charged roller 17, and an electrostatic latent image is formed on it when the photosensitive drum 11 is irradiated with a laser. Thereafter, the toner contained in the receiving section 18 is conveyed to the photosensitive drum 11 by the developing roller 12, the electrostatic image is developed by the developing roller 12 and the toner image is formed on the photosensitive drum 11.

[0033] Recording material P is fed from the feed tray 4 in parallel with the image forming process described above. Pick-up roller 3, feed roller 5a, and transfer roller pair 5c are arranged on the transport path in the image forming apparatus 1. Pick-up roller 3 contacts the uppermost recording material P among the recording materials P contained in the feed tray 4 and feeds the recording material P as the pick-up roller 3 rotates. Feed roller 5a and separation roller 5b, which are in pressure contact with it, form a separation clamping section. If multiple recording materials P are accidentally fed into the separation clamping section due to friction between them, feed roller 5a and separation roller 5b separate the multiple recording materials P and feed only the uppermost recording material P to the downstream side.

[0034] Recording material P, fed from feed tray 4, is conveyed toward transfer roller 7 by transfer roller pair 5c. With a transfer bias applied to transfer roller 7, the toner image formed on photosensitive drum 11 is transferred onto recording material P. Recording material P, with the toner image transferred onto it by transfer roller 7, undergoes heating and pressurization processing by fixing device 9, and then the toner image is fixed onto recording material P. Fixing device 9 includes a heating roller 9a containing a fixing heater built into it and a pressure roller 9b biased toward the heating roller 9a. Recording material P, with the toner image fixed thereon, is then discharged onto discharge tray 14 via discharge roller pair 10.

[0035] When an image is formed on both sides of the recording material P, the discharge roller pair 10 guides the recording material P to the double-sided conveying path 16 by switching back the recording material P on its first surface where the image is formed.

[0036] The recording material P, guided to the double-sided conveying path 16, is again conveyed toward the transfer roller 7 via the double-sided conveying roller pair 5d and the conveying roller pair 5c. After an image is formed on the second surface of the recording material P on the back side of the first surface of the transfer roller 7, the recording material P is discharged onto the discharge tray 14 via the discharge roller pair 10.

[0037] After the toner image is transferred onto the recording material P, the toner remaining on the photosensitive drum 11 is removed by the cleaning unit 13.

[0038] The housing 72 includes a control board 100. The control board 100 includes a wiring board (first board, first board unit, or first printed circuit board) 101, a control unit (central processing unit (CPU) or arithmetic device) 199, and a connector (first connection unit or body-side connection unit) 131. The control unit 199 and the connector 131 are mounted on the wiring board 101 by soldering, and the control unit 199 and the connector 131 are electrically connected to each other.

[0039] The detection unit 150 is mounted on the developing unit 230. The detection unit 150 includes a wiring board (second board, second board unit, or second printed circuit board) 151, a connector (second connection unit or unit-side connection unit) 152, and a toner residue sensor 51, which will be described below. The connector 152 and the toner residue sensor 51 (the light-emitting unit 51a and light-receiving unit 51b, which will be described below) are mounted on the wiring board 151 by soldering, and the connector 152 and the toner residue sensor 51 are electrically connected to each other.

[0040] The control unit 199 controls the operation of the image forming apparatus 1, thereby performing an image forming operation on the recording material P. For example... Figure 2 As illustrated, the control board 100 is arranged such that the surface of the wiring board 101 intersects the discharge direction. Additionally, the wiring board 101 is disposed between the front cover 70 and the scanner unit 50 in the discharge direction. In this exemplary embodiment, the detection unit 150 and the control board 100 are deployed in a position where they face each other, but they could also be deployed in a position where they do not face each other.

[0041] The image forming apparatus 1 includes a connecting member 141 connected to connectors 131 and 152, such that connectors 131 (first connector) and 152 (second connector) are electrically connected to each other. The connecting member 141 functions as a signal input / output line that electrically connects control board 100 and detection unit 150 via connectors 152 and 131.

[0042] It is desirable to use wires, including conductors covered with an insulating layer, as the connecting member 141. Examples that can be used as the connecting member 141 include multiple wires, cables with multiple wires bundled together, and wire harnesses consisting of multiple wires with connectors attached to both ends. Alternatively, flexible flat cables can also be used as the connecting member 141.

[0043] <Developer roller contact / separation operation>

[0044] Reference Figure 2 and Figure 3 This describes the contact / separation operation between the developing roller 12 and the photosensitive drum 11. Figure 3 The illustration shows the internal configuration of the image forming apparatus 1 when viewed from the X direction (the direction of the rotation axis of the photosensitive drum 11).

[0045] The developing unit 230 is movable relative to the housing 72 and the photosensitive unit 300. In other words, the developing unit 230 is movable relative to the photosensitive drum 11. The developing unit 230 can be moved relative to the photosensitive unit 300 to the contact position (first position) where the developing roller 12 abuts against the photosensitive drum 11. Figure 2) and the separation position (second position) where the developing roller 12 separates from the photosensitive drum 11 ( Figure 3 ).

[0046] A moving unit (developing moving unit or moving device) 400 is provided in the housing 72 to move the developing unit 230 to an abutting position and a separating position. In this exemplary embodiment, the developing unit 230 is moved from the abutting position to the separating position by being pushed by the moving unit 400, and from the separating position to the abutting position by being separated from the developing unit 230 by the moving unit 400. However, this exemplary embodiment is not limited thereto. For example, the developing unit 230 may be configured to be moved from the separating position to the abutting position by being pushed by the moving unit 400, and from the abutting position to the separating position by being separated from the developing unit 230 by the moving unit 400. Alternatively, the developing unit 230 may be configured to be moved from the separating position to the abutting position and from the abutting position to the separating position by being pushed by the moving unit 400.

[0047] The developing roller 12 and the photosensitive drum 11 can be protected by properly separating the developing roller 12 from the photosensitive drum 11.

[0048] In this exemplary embodiment, when the developing unit 230 is in at least one of the contact position and the separation position, the wiring board 101 and the wiring board 151 face each other.

[0049] <Scanner Irradiation Area>

[0050] Figure 4 This is a top view of the image forming apparatus 1 with its outer cover 71 removed. The housing 72 includes side walls 73 and 74. The connecting member 141 is positioned to avoid areas irradiated by laser light emitted from the scanner unit 50. Figure 4 (The grid-like shaded area in the image). More specifically, the connecting member 141 is located outside the area irradiated by the laser emitted from the scanner unit 50 in the direction of the rotation axis of the photosensitive drum 11.

[0051] <Processing Unit Configuration>

[0052] Reference Figures 5A to 5C as well as Figure 6A and Figure 6B To describe processing unit 500. Figure 5A This is a perspective view illustrating the processing unit 500. Figure 5B This is a perspective view illustrating the wiring board 151 and the board holding member 710, and Figure 5C This is a perspective view of a processing unit 500 on which a wiring board 151 and a board holding member 710 are mounted. Figure 6A and Figure 6BThis is a cross-sectional view of processing unit 500. Figure 6A It is a cross-sectional view in the direction perpendicular to the axial direction of the developing roller 12, and Figure 6B It is along Figure 6A The cross-sectional view taken from line 6B-6B in the diagram.

[0053] like Figure 5A As shown in the diagram, the developing unit 230 of the processing unit 500 includes a developing container 320 and a developing cap 321. The developing container 320 and the developing cap 321 are joined together to form a frame member (developing frame member) 340 of the developing unit 230. A toner-containing container 18 (see reference) Figure 2 and Figure 3 The developing roller 12 is set in the frame member 340. The developing roller 12 is supported by the frame member 340.

[0054] The developing cover 321, which forms part of the frame member 340, includes plate positioners 321a and 321b and plate fixing portions 321c and 321d, and a light guide (light guide member or light path forming member) 610 is disposed between the plate fixing portions 321c and 321d of the developing cover 321.

[0055] The light guide 610 includes a first guide portion 610a and a second guide portion 610b. The first guide portion 610a guides the light emitted from the light-emitting unit 51a, which will be described below, into the receiving portion 18 of the frame member 340. The second guide portion 610b guides the light that passes through the first guide portion 610a and the interior of the receiving portion 18 into the light-receiving unit 51b, which will be described below.

[0056] Plate positioners 321a and 321b, serving as positioning units, are respectively deployed on the outer side of plate fixing parts 321c and 321d in the longitudinal direction LD of frame member 340. The longitudinal direction LD of frame member 340 is the same as the longitudinal direction LD of processing unit 500, and also the same as the rotation axis direction of photosensitive drum 11 and the rotation axis direction of developing roller 12.

[0057] In this exemplary embodiment, as Figure 5C As shown in the diagram, the wiring board 151 and the board holding member 710 are attached to the developing cover 321. The board holding member 710 is attached to the developing cover 321 in a position where it is inserted between the developing cover 321 and the wiring board 151.

[0058] The detection unit 150 is mounted on the developing unit 230. The detection unit 150 includes 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 transmitted through the light guide 610 into the interior of the receiving portion 18, and a connector 152. The light-emitting unit 51a and the light-receiving unit 51b are electrically connected to the connector 152.

[0059] like Figure 5B As illustrated, a light-emitting unit 51a, a light-receiving unit 51b, and a connector 152 are mounted on a wiring board 151. In this exemplary embodiment, a light-emitting diode (LED) is used as the light-emitting unit 51a, and a phototransistor configured to switch to an on state upon response to light from the LED is used as the light-receiving unit 51b, but the light-emitting unit 51a and the light-receiving unit 51b are not limited thereto. For example, a halogen lamp or a fluorescent lamp can be used as the light-emitting unit 51a, and a photodiode or an avalanche photodiode can be used as the light-receiving unit 51b. A connecting member 141 is connected to the connector 152. Due to this connection, 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. This allows power to be supplied to the light-emitting unit 51a and also allows signals output from the light-receiving unit 51b to be transmitted to the control board 100.

[0060] Additionally, the wiring board 151 includes positioning holes 151c and 151d through which board locators 321a and 321b are inserted and fitted, and board fixing holes 151a and 151b through which screws fixed to the board fixing portions 321c and 321d can pass.

[0061] Additionally, the board holding member 710 includes positioning holes 710c and 710d through which board positioners 321a and 321b are inserted and fitted, and board fixing holes 710a and 710b through which screws for fixing to board fixing portions 321c and 321d can pass. Furthermore, the board holding member 710 includes a first hole 711a through which a first guide portion 610a of the light guide 610 is inserted, and a second hole 711b through which a second guide portion 610b of the light guide 610 is inserted. The first hole 711a and the second hole 711b are tubular in shape. The board holding member 710, acting as a holder, holds the wiring board 151.

[0062] The plate holding member 710 is positioned relative to the developing cover 321 by being inserted through positioning holes 710c and 710d and fitted therein by plate positioners 321a and 321b of the developing cover 321.

[0063] Additionally, the wiring board 151 is positioned relative to the developing cover 321 by inserting and engaging with the board positioners 321a and 321b of the developing cover 321 through positioning holes 151c and 151d, respectively. The board positioners 321a and 321b are used together to position the board holding member 710 and the wiring board 151 in this manner, which can further precisely position the developing cover 321, the board holding member 710, and the wiring board 151.

[0064] Furthermore, when the plate holding member 710 and the wiring board 151 are positioned relative to the developing cover 321, screws are inserted into the plate fixing holes 710a, 710b, 710c, and 710d, and are fixed to the plate fixing portions 321c and 321d of the developing cover 321. As a result, the plate holding member 710 and the wiring board 151 are fixed to the developing cover 321 using a single screw, and the plate holding member 710 and the wiring board 151 are fixed to the developing cover 321.

[0065] When the plate holding member 710 and the wiring board 151 are attached to the developing cover 321, the first guide portion 610a of the light guide member 610 is inserted into the first hole portion 711a of the plate holding member 710. Then, the first guide portion 610a is positioned near the light-emitting unit 51a of the wiring board 151. Similarly, the second guide portion 610b of the light guide member 610 is inserted into the second hole portion 711b of the plate holding member 710. Then, the second guide portion 610b is positioned near the light-receiving unit 51b of the wiring board 151.

[0066] As described above, the plate holding member 710 and the wiring plate 151 are precisely positioned relative to the developing cover 321, which ensures that the light emitted from the light-emitting unit 51a is guided by the first guide portion 610a. Then, the light guided by the first guide portion 610a to the receiving portion (receiving chamber) 18 inside the frame member 340 is transmitted from the first guide portion 610a in the longitudinal direction LD.

[0067] Then, the light traveling along the optical path Q1 inside the receiving portion 18 is guided by the second guide portion 610b to the outside of the frame member 340. The second guide portion 610b is deployed near the light receiving unit 51b, which ensures that the light output from the second guide portion 610b is received by the light receiving unit 51b. Therefore, the light emitting unit 51a and the light receiving unit 51b can be used to detect the amount of toner residue with improved accuracy.

[0068] The layout of the light-emitting unit 51a and the light-receiving unit 51b will now be described in further detail. In the frame member 340, the light-emitting unit 51a and the light-receiving unit 51b are positioned at the ends opposite to the ends where the developing roller 12 is positioned. Furthermore, the light-emitting unit 51a and the light-receiving unit 51b are located at the center portion of the receiving portion 18 in the longitudinal direction LD. Because the light-emitting unit 51a and the light-receiving unit 51b are located at the center portion of the receiving portion 18, the amount of toner residue in the receiving portion 18 can be effectively detected. More specifically, the developer (toner) may be unevenly distributed at the ends of the receiving portion 18 in the longitudinal direction LD, but less distributed at the center portion of the receiving portion 18, thus allowing the detection of the actual amount of toner residue.

[0069] When the developing unit 230 moves between the contact position and the separation position, the frame member 340 also moves. Since the detection unit 150 is fixed to the frame member 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) relative to the control board 100 and the photosensitive unit 300 of the housing 72, together with the developing unit 230. The detection unit 150 is mounted on 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 separation position.

[0070] <Detection of Colorant Residue>

[0071] The control unit 199 performs a detection operation (detection of the amount of toner contained in the container 18) based on the signal output from the light receiving unit 51b.

[0072] Figure 7 This is a circuit diagram illustrating an example of the circuit configuration of a toner residue sensor 51 mounted on a detection unit 150. The toner residue sensor 51 includes a light-emitting unit 51a and a light-receiving unit 51b.

[0073] The light-emitting unit 51a and the light-receiving unit 51b are connected to the connector 131 of the control board 100 via the connector 152 and the connecting member 141.

[0074] The power supply voltage Vcc and the current-limiting resistor R1 are connected to the light-emitting unit 51a, and the light-emitting unit 51a emits light using the current determined by the current-limiting resistor R1. The light emitted from the light-emitting unit 51a passes through the optical path Q1 ( Figure 7 (Not shown in the diagram) and received by the light-receiving unit 51b. The power supply voltage Vcc and the detection resistor R2 are connected to the collector terminal and the emitter terminal of the light-receiving unit 51b, respectively. The light-receiving unit 51b, acting as 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 into a voltage V1 by the detection resistor R2 and input to the analog-to-digital (A / D) conversion unit (not shown) of the control unit 199 included in the control board 100.

[0075] In other words, the light-receiving unit 51b changes the output value according to the amount of toner (developer) contained in the accommodating section 18.

[0076] Compared to when the toner residue sensor 51 is mounted on the housing 72, mounting the toner residue sensor 51 of the detection unit 150 to the developing unit 230, as described above, allows for a reduction in the distance of the optical path Q1. Compared to the configuration where the toner residue sensor 51 is mounted on the housing 72, this configuration allows for improved positional accuracy of the light-emitting unit 51a and the light-receiving unit 51b relative to the optical path Q1. In other words, this configuration helps reduce variations when the light-receiving unit 51b receives light emitted from the light-emitting unit 51a, thereby improving the accuracy of toner detection.

[0077] The control unit 199 determines whether the light-receiving unit 51b receives light from the light-emitting unit 51a based on the input voltage level. When the stirring member 34 (see reference 18) is contained in the receiving section 18... Figure 6A When the toner is rotated and thus stirred for a predetermined time, the control unit 199 can calculate the amount of toner in the container 18 based on the length of time the light is detected by the light receiving unit 51b and the intensity of the light.

[0078] <Length of connecting component>

[0079] When the developing unit 230 moves between the contact position and the separation position, as described above, the connector 152 shifts relative to the connector 131, thus changing the distance between the connector 152 and the connector 131. Therefore, if the length of the connecting member 141 is too short, the connecting member 141 interferes with the movement of the developing unit 230. Accordingly, the length of the connecting member 141 is set to not interfere with the movement of the developing unit 230. In the following description, the length of the connecting member 141 according to this exemplary embodiment will be described.

[0080] Assuming distance D1 (first distance) represents when the developing unit 230 is as follows: Figure 2 The diagram shows the distance between connector 131 of control board 100 and connector 152 of detection unit 150 when they are in the contact position. Assume distance D2 (second distance) represents the distance when development unit 230 is in the contact position. Figure 3 The diagram shows the distance between connector 131 of control board 100 and connector 152 of detection unit 150 when in the separated position. The length of connecting member 141 is longer than both distances D1 and D2, so as not to interfere with the movement of developing unit 230. In addition, connecting member 141 is expected to be flexible.

[0081] The distance between connector 131 and connector 152 specifically refers to the shortest distance between the portions of connecting member 141 into which it is inserted. Additionally, the length of connecting member 141 refers to the length along the surface of connecting member 141 from connector 131 to connector 152.

[0082] Furthermore, in this exemplary embodiment, distance D1 is longer than distance D2. In other words, the length of the connecting member 141 is longer than distance D1.

[0083] As described above, when the developing unit 230 moves, the detection unit 150 also moves in coordination with it. At this time, an elastic force that biases the connecting member 141 to return to its initial position acts on the connector 152 of the detection unit 150, thus applying an opposing force in the direction of movement of the developing unit 230. If the elastic force of the connecting member 141 exceeds the force used to move the developing unit 230, the developing unit 230 cannot move to the desired position, and the contact / separation operation of the developing unit 230 is hindered.

[0084] Accordingly, by making the length of the connecting member 141 longer than the distances D1 and D2, the elastic 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 longer than the distances D1 and D2.

[0085] The connecting member 141 is preferably longer than the longer of distances D1 and D2. In this exemplary embodiment, the length of the connecting member 141 is set such that the difference between the connecting member 141 and distance D1 exceeds the difference between distances D1 and D2. Furthermore, because the connecting member 141 has an additional length, it can be attached to both connectors 152 and 131 while being partially bent. In this case, by setting the bent portion of the connecting member 141 closer to connector 152 than connector 131, the effect of the elastic force of the connecting member 141 generated during the movement of the developing unit 230 on connector 152 can be minimized. In other words, the bent portion of the connecting member 141 is preferably deployed such that the distance between the bent portion and connector 152 is shorter than the distance between the bent portion and connector 131.

[0086] In this manner, according to the configuration of this exemplary embodiment, the detection unit 150 is mounted on the developing unit 230, preventing misalignment between the light-emitting unit 51a, the light-receiving unit 51b, and the developing unit 230 even when the developing unit 230 moves between the contact position and the separation position. Furthermore, since the connecting member 141 has sufficient length, interference with the contact / separation operation of the developing unit 230 is prevented.

[0087] In this exemplary embodiment, the connecting member 141 is used to connect the detection unit 150 for detecting the amount of toner residue and the control board 100, but it can also be used to connect a part with other functions to the housing 72.

[0088] Furthermore, since the length of the connecting member 141 is longer than the distances D1 and D2, the electrical connection between connector 131 and connector 152 is maintained when the developing unit 230 is in the contact position and when the developing unit 230 is in the separation position. Therefore, the control unit 199 can detect the amount of toner residue both when the developing unit 230 is in the contact position and when the developing unit 230 is in the separation position.

[0089] In the second exemplary embodiment, a description of the image forming apparatus 1A and developing unit 230A with a different configuration from that of the image forming apparatus 1 according to the first exemplary embodiment will be given. Descriptions and illustrations of configurations similar to those described in the first exemplary embodiment may be omitted, and in the descriptions and illustrations, components similar to those described in the first exemplary embodiment may be designated with the same reference numerals and symbols.

[0090] The image forming apparatus 1A according to this exemplary embodiment includes a developing unit 230A. As will be described below, in addition to the configuration of the developing unit 230 according to the first exemplary embodiment, the developing unit 230A also includes a receiving section 202, to which a replenishment packet (replenishment container) 210 for replenishing toner into the receiving section 18 is detachably attached. Similar to the first exemplary embodiment, a detection unit 150 is also mounted on the developing unit 230A. In the following description, reference will be made to… Figures 8A to 8C and Figure 9 The image forming apparatus 1A according to this exemplary embodiment will be described.

[0091] Figures 8A to 8C The diagram shows support unit 250. Figure 8A The diagram shows the support unit 250 in its retracted state. Figure 8B The diagram shows the support unit 250 in the initial support state. Figure 8C The diagram shows the support unit 250 in a supported state. Figure 8A , Figure 8B and Figure 8C This is a side view taken along the rotation axis of the photosensitive drum 11.

[0092] As described above, the developing unit 230A according to this exemplary embodiment includes a receiving portion 202 to which a supplementary package 210 is attached. On the other hand, an attachment portion 201 is provided in the housing 72 of the image forming apparatus 1A according to this exemplary embodiment. The supplementary portion 200 is formed by the receiving portion 202 and the attachment portion 201.

[0093] The discharge tray 14 disposed in the housing 72 of the image forming apparatus 1A is configured to cover the receiving part 202 and the attachment part 201 at a covering position. Figure 8AThe exposed positions of the discharge tray 14, the exposed receiving part 202, and the exposed attachment part 201. Figure 8C The opening / closing member is movable between the receiving part 202 and the attachment part 201. Moving the discharge tray 14 to the exposed position exposes the receiving part 202 and the attachment part 201, thereby allowing the replenishment package 210 to be attached to the receiving part 202 and the attachment part 201.

[0094] The refill pack 210 contains toner. The refill pack 210 is attached to the receiving part 202 and the attachment part 201, and is activated by operating the lever 201a of the attachment part 201. Figure 9 The baffle of the refill pack 210 is opened, and the toner is added from the refill pack 210 into the container 18.

[0095] Reference Figures 8A to 8C This describes the operation of the developing unit 230A when the discharge tray 14 is opened / closed to replenish toner.

[0096] The support unit 250 is disposed inside the housing 72 of the image forming apparatus 1A according to this exemplary embodiment. The supplementary package 210 is inserted into the receiving section 202. At this time, a force for attaching the supplementary package 210 is applied to the receiving section 202 of the developing unit 230A. When the supplementary package 210 is attached, the developing unit 230A is prevented from moving by supporting it with the support unit 250.

[0097] When the replenishment pack 210 is attached 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 orientation of the developing unit 230A can be stabilized when the replenishment pack 210 is attached.

[0098] The support unit 250 includes a tray gear (driving member or 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 linkage (linkage member), which connects the discharge tray 14 and the support member 233 in a manner that interlocks with the support member 233.

[0099] The supplementary package 210 is attached vertically from above to the receiving section 202. The support member 233 supports the receiving section 202 vertically from below. The support member 233 includes a first cam portion 233a that serves as a support portion located below the receiving section 202 in the vertical direction and supporting the developing unit 230A, and a gear portion 233c that meshes with the idler gear 232.

[0100] The tray gear 231 is fixed to the discharge tray 14 and pivotally moves in coordination with the opening / closing of the discharge tray 14. The tray gear 231 engages with a shaft located at the pivot center of the discharge tray 14. The support member 233 is coupled to the tray gear 231 via a freewheeling gear 232. The support member 233 is configured to be movable between a supported position in which the first cam portion 233a contacts and supports the developing unit 230A, and a retracted position in which the support member 233 retracts from the supported position. The support member 233 moves between the supported position and the retracted position in coordination with the movement of the discharge tray 14. The state in which the support member 233 is in the supported position is referred to as the supported 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 referred to as the retracted state of the support member 233 and the support unit 250.

[0101] 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.

[0102] The developing unit 230A is pivotally disposed relative to the photosensitive unit 300 about an axis DR extending in the pivot direction. The developing unit 230A moves between an contact position and a separation position by pivoting about the axis DR. When the developing unit 230A moves in the DC direction, the developing roller 12 moves toward the photosensitive drum 11. When the developing unit 230A moves in the DS direction, the developing roller 12 moves away from the photosensitive drum 11.

[0103] When in the supported 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.

[0104] When the support member 233 is in the retracted position, the first cam portion 233a of the support member 233a separates from the developing unit 230A. The developing roller 12 is positioned where it can develop the electrostatic latent image formed on the photosensitive drum 11 (the position where the developing roller 12 abuts against the photosensitive drum 11). In other words, the developing unit 230A is in the abutting position.

[0105] The control unit 199 of the image forming apparatus 1A allows image forming operations to be performed when the support member 233 is in the retracted position. The control unit 199 also restricts image forming operations to be performed when the support member 233 is in the supported position.

[0106] In other words, control unit 199 allows image forming operations to be performed when the discharge tray 14 is in the covered position. Control unit 199 restricts image forming operations to be performed when the discharge tray 14 is in the exposed position.

[0107] The image forming apparatus 1A includes an open / close sensor (output unit or 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. Because the discharge tray 14 and the support member 233 operate cooperatively with each other, it can be said that the open / close sensor 239 outputs a signal corresponding to the position of the support member 233, and also that the open / close sensor 239 outputs 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 image forming apparatus 1A can detect the position of the other of the discharge tray 14 and the support member 233. In this exemplary embodiment, the control unit 199 is configured to allow or restrict the execution of an image forming operation based on the output (signal) of the open / close sensor 239.

[0108] The receiving section 202 is provided with a support target section 202f. As described above, when the discharge tray 14 is closed, the first cam section 233a of the support member 233 is in a state separated from the support target section 202f of the developing unit 230A (see reference). Figure 8A At this time, the developing unit 230A is located at the contact position where the developing roller 12 and the photosensitive drum 11 abut. Since the first cam portion 233a is separated from the support target portion 202f, the photosensitive drum 11 and the developing roller 12 can be stably kept in contact with each other, and the developing roller 12 is set to a state in which it can develop electrostatic latent images.

[0109] like Figure 8A As illustrated, when the discharge tray 14 is in the covered position and the support member 233 is in the retracted position, the open / close sensor 239 is separated from the second cam portion 233b. At this time, the signal state of the open / close sensor 239 is in the closed state (first state). At this time, the control unit 199 allows the image forming operation to be performed.

[0110] like Figure 8C As illustrated, when the discharge tray 14 is in the exposed position and the support member 233 is in the supported position, the open / close sensor 239 contacts the second cam portion 233b. At this time, the signal state of the open / close sensor 239 is in the open state (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.

[0111] In summary, the control unit 199 can control the image forming apparatus 1A to prevent the image forming apparatus 1A from starting image forming operation when the open / close sensor 239 is in the open state.

[0112] When the discharge tray 14 is opened (i.e., when the discharge tray 14 is in the exposed position), the support member 233 is in the supported position and the developing unit 230A is in the retracted position where the developing unit 230A has retracted from the abutment position. At this time, the developing roller 12 is separated from the photosensitive drum 11. In addition, the receiving part 202 engages with the attachment part 201, and the user can replenish toner by attaching the refill pack 210 to the refill part 200.

[0113] When the user attaches the refill pack 210 to the receiving unit 202, the developing unit 230A receives force in the direction DC of the developing roller 12 near the photosensitive drum 11. At this time, the developing unit 230A is supported by the support member 233, which stabilizes the orientation of the developing unit 230A, thereby allowing the refill pack 210 to be attached stably. In addition, when the refill pack 210 is attached, it prevents the developing roller 12 from being pressed against the photosensitive drum 11.

[0114] Figure 9 This is a top view of the image forming apparatus 1A according to this exemplary embodiment. The connector 131, connector 152, and connecting member 141 according to this exemplary embodiment are deployed at a position closer to the center of the housing 72 (the center of the image forming apparatus 1A) than in the first exemplary embodiment.

[0115] In this exemplary embodiment, the length of the connecting member 141 is also longer than both distances D1 and D2. Furthermore, in this exemplary embodiment, distance D1 is also longer than distance D2.

[0116] like Figure 9 As illustrated in the figure, the connecting member 141 according to this exemplary embodiment is deployed near the area irradiated by the laser emitted from the scanner unit 50. Therefore, if the length of the connecting member 141 is too long, the connecting member 141 will undesirably interfere with the irradiation of the laser.

[0117] In view of this situation, in this exemplary embodiment, a movable flexible flat cable is used as the connecting member 141. More specifically, when a force is applied to the connecting member 141 during the movement of the developing unit 230A, the connecting member 141 deforms, thereby suppressing the generation of elastic force.

[0118] Reference Figure 10 The layout of the connecting member 141 is described in further detail. Figure 10 The layout of the connecting member 141 according to this exemplary embodiment is illustrated.

[0119] Assume that the length direction of the connecting member 141 is along the surface of the connecting member 141 from the connector 131 to the connector 152. Figure 10 This is a cross-sectional view of the connecting member 141 in the direction perpendicular to the length direction. In the direction perpendicular to the length direction, the width W of the connecting member 141 is greater than the thickness t of the connecting member 141.

[0120] As described above, the developing unit 230A pivots about an axis DR that extends in the pivot direction. The pivot direction of the axis DR is parallel to the longitudinal direction LD.

[0121] By arranging the connecting member 141 in such a way that its width W direction (width direction) extends parallel to the pivot direction of the shaft DR, the connecting member 141 is easily deformable when the developing unit 230A is pivotally moved. Therefore, the elastic force received from the connecting member 141 when the developing unit 230A is pivotally moved can be suppressed to a low level.

[0122] Furthermore, by arranging the connecting member 141 so that its width direction and longitudinal direction LD are parallel to each other, movement of the connecting member 141 in the longitudinal direction is prevented when the connecting member 141 deforms. Therefore, overlap between the connecting member 141 and the area irradiated by the laser can be prevented.

[0123] From the above perspective, it is desirable that the angle θ defined between the width direction of the connecting member 141 and the pivot direction of the axis DR be small. The angle θ described here refers to the narrower of the angles formed between the width direction of the connecting member 141 and the pivot direction of the axis DR. Furthermore, it is desirable that the angle θ defined between the width direction of the connecting member 141 and the longitudinal direction LD be small. The angle θ described here refers to the narrower of the angles formed between the width direction of the connecting member 141 and the longitudinal direction LD. The degree of angle θ is desirable to be 45° or less. Even when the developing unit 230A does not include the receiving section 202, the degree of angle θ is desirable to be set to the degree indicated herein.

[0124] In this manner, according to the configuration of this exemplary embodiment, the detection unit 150 is mounted on the developing unit 230A, preventing misalignment between the light-emitting unit 51a, the light-receiving unit 51b, and the developing unit 230A even when the developing unit 230A moves between the contact position and the separation position. Furthermore, since the connecting member 141 has sufficient length, interference with the contact / separation operation of the developing unit 230A is prevented.

[0125] Furthermore, since the length of the connecting member 141 is longer than the distances D1 and D2, the electrical connection between connectors 131 and 152 is maintained when the developing unit 230A is in the contact position and when the developing unit 230A is in the separation position. Therefore, the control unit 199 can detect the amount of toner remaining both when the developing unit 230A is in the contact position and when the developing unit 230A is in the separation position. In other words, the amount of toner in the container 18 can be detected while toner is being replenished from the refill pack 210. This allows the image forming apparatus 1A to present information related to replenishing toner from the refill pack 210 to the user and to perform control related to replenishing toner from the refill pack 210.

[0126] In the manner described above, according to exemplary embodiments of the present disclosure, an image forming apparatus including a movably configured developing unit can prevent changes in the position of the light-emitting element and the light-receiving element relative to the developing unit.

[0127] While this disclosure has been described with reference to exemplary embodiments, it is to be understood that this disclosure is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be given the broadest interpretation to include all such modifications and equivalent structures and functions.

Claims

1. An image forming apparatus configured to form an image on a recording material, the image forming apparatus comprising: A housing, the housing including a first connector; A drum unit, comprising a photosensitive drum, is housed within the housing; The developing unit includes a receiving portion for containing toner and a developing roller configured to supply the toner to the photosensitive drum. The developing unit is housed in the housing and is movable relative to the drum unit between (i) an contact position where the developing roller abuts against the photosensitive drum and (ii) a separation position where the developing roller is separated from the photosensitive drum. A light-emitting element, wherein the light-emitting element is mounted on the developing unit; A light-receiving element is mounted on the developing unit and is configured to receive light emitted from the light-emitting element and transmitted through the receiving portion; A second connector is mounted on the developing unit and is electrically connected to the light-emitting element and the light-receiving element. as well as A connecting member is provided, which is connected to the first connector and the second connector, such that the first connector and the second connector are electrically connected to each other. When the developing unit moves between the contact position and the separation position, the second connector shifts relative to the first connector, and The length of the connecting member is longer than a first distance from the first connector to the second connector when the developing unit is in the abutting position, and longer than a second distance from the first connector to the second connector when the developing unit is in the separating position. The developing unit includes a receiving section, and a replenishment container for adding toner to the receiving section is detachably attached to the receiving section. The housing includes an opening / closing member and a supporting member. The opening / closing member is movable between a covered position where it covers the receiving part and an exposed position where it exposes the receiving part. The supporting member is movable between a supported position where it supports the developing unit and the developing unit is in a separated position, and a retracted position where it retracts from the supported position and the developing unit is in an abutment position. Specifically, when the opening / closing member is in the exposed position, the supporting member is in the supporting position, and when the opening / closing member is in the covered position, the supporting member is in the retracted position.

2. The image forming apparatus according to claim 1, further comprising: The first board, the first connector is mounted on the first board; as well as The second board, on which the light-emitting element, the light-receiving element, and the second connector are mounted, is a second board. When the developing unit is located in at least one of the contact position and the separation position, the first plate and the second plate face each other.

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

4. The image forming apparatus according to claim 3, wherein, If the direction along the surface of the connecting member extending from the first connector to the second connector is the length direction of the connecting member, then in the direction perpendicular to the length direction, the width of the connecting member is greater than the thickness of the connecting member.

5. The image forming apparatus according to claim 4, in, The developing unit is pivotally configured relative to the drum unit about an axis extending in a pivotal direction, and The angle between the width direction of the connecting member and the pivot direction is less than or equal to 45°.

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

7. The image forming apparatus according to claim 1, further comprising a control unit configured to perform a detection operation based on a signal output from the light-receiving element to detect the amount of toner contained in the accommodating portion.

8. The image forming apparatus according to claim 7, wherein, The control unit is configured to perform the detection operation both when the developing unit is in the contact position and when the developing unit is in the separation position.

9. An image forming apparatus configured to form an image on a recording material, the image forming apparatus comprising: A housing, the housing including a first connector; A drum unit, comprising a photosensitive drum, is housed within the housing; A developing unit, the developing unit including a container for holding toner and a developing roller configured to supply the toner to the photosensitive drum, the developing unit being housed in the housing and movable relative to the drum unit between (i) a first position and (ii) a second position; A light-emitting element, wherein the light-emitting element is mounted on the developing unit; A light-receiving element is mounted on the developing unit and is configured to receive light emitted from the light-emitting element and transmitted through the receiving portion; A second connector is mounted on the developing unit and is electrically connected to the light-emitting element and the light-receiving element. as well as A connecting member is provided, which is connected to the first connector and the second connector, such that the first connector and the second connector are electrically connected to each other. When the developing unit moves between the first position and the second position, the second connector shifts relative to the first connector, and The length of the connecting member is longer than a first distance from the first connector to the second connector when the developing unit is in the first position, and longer than a second distance from the first connector to the second connector when the developing unit is in the second position. The developing unit includes a receiving section, and a replenishment container for adding toner to the receiving section is detachably attached to the receiving section. The housing includes an opening / closing member and a supporting member. The opening / closing member is movable between a covered position where it covers the receiving part and an exposed position where it exposes the receiving part. The supporting member is movable between a supported position where it supports the developing unit and the developing unit is in a second position, and a retracted position where it retracts from the supported position and the developing unit is in the first position. Specifically, when the opening / closing member is in the exposed position, the supporting member is in the supporting position, and when the opening / closing member is in the covered position, the supporting member is in the retracted position.

10. The image forming apparatus according to claim 9, further comprising: The first board, the first connector is mounted on the first board; as well as The second board, on which the light-emitting element, the light-receiving element, and the second connector are mounted, is a second board. When the developing unit is located in at least one of the first position and the second position, the first plate and the second plate face each other.

11. The image forming apparatus according to claim 9, wherein, The connecting member is flexible.

12. The image forming apparatus according to claim 11, wherein, If the direction along the surface of the connecting member extending from the first connector to the second connector is the length direction of the connecting member, then in the direction perpendicular to the length direction, the width of the connecting member is greater than the thickness of the connecting member.

13. The image forming apparatus according to claim 12, wherein, The developing unit is pivotally configured relative to the drum unit about an axis extending in a pivotal direction, and The angle between the width direction of the connecting member and the pivot direction is less than or equal to 45°.

14. The image forming apparatus according to claim 9, wherein, The first distance is longer than the second distance.

15. The image forming apparatus according to claim 9, further comprising a control unit configured to perform a detection operation based on a signal output from the light-receiving element to detect the amount of toner contained in the accommodating portion.

16. The image forming apparatus according to claim 15, wherein, The control unit is configured to perform the detection operation when the developing unit is in the first position and when the developing unit is in the second position.

Images