Image forming apparatus body and image forming apparatus

Abstract

To provide a novel technique related to a configuration that optically detects the amount of developer.SOLUTION: An image forming apparatus body comprises: an opening member; urging means; a detection unit that is provided movably relative to the opening member between a first position and a second position; and a shield member that is provided movably relative to both the opening member and the detection unit between a third position and a fourth position. When the detection unit is located at the first position and the shield member is located at the third position, at least part of a light emitting part or at least part of a light receiving part is located inside an opening and shielded by the shield member. When the detection unit is located at the second position and the shield member is located at the fourth position, the light emitting part and the light receiving part are located inside the opening and not shielded by the shield member.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus for forming an image on a recording material, and to a main body of the image forming apparatus. [Background technology]

[0002] In electrophotographic image forming apparatuses, a configuration is used in which a cartridge containing toner as a developer, such as a process cartridge or a developing cartridge, is detachably attached to the image forming apparatus main body. Patent Document 1 describes that a toner detection means disposed in the image forming apparatus main body and equipped with a light emitting section and a light receiving section optically detects the amount of toner remaining inside the process cartridge attached to the image forming apparatus main body. In the configuration described in this document, the light emitting section and the light receiving section are not covered before the process cartridge is attached to the image forming apparatus main body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-107775 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a new technique for optically detecting the amount of developer. [Means for solving the problem]

[0005] One aspect of the present invention is a detection unit having an opening member having an opening, a biasing means, a light-emitting portion that emits light, a light-receiving portion that emits a detection signal according to the amount of light received from the light-emitting portion, and a pressure-receiving portion, the detection unit being provided movably with respect to the opening member between a first position and a second position, being positioned at the first position by the biasing force of the biasing means, and being moved from the first position to the second position against the biasing force of the biasing means by pressing the pressure-receiving portion, and a detection unit being provided movably with respect to both the opening member and the detection unit between a third position and a fourth position. and a shielding member shielded by the shielding member when viewed in the optical axis direction of the light-emitting unit when the detection unit is located at the first position and the shielding member is located at the third position, at least a part of the light-emitting unit or at least a part of the light-receiving unit is located inside the opening and shielded by the shielding member, and when the detection unit is located at the second position and the shielding member is located at the fourth position, the light-emitting unit and the light-receiving unit are located inside the opening and not shielded by the shielding member when viewed in the optical axis direction.

[0006] Another aspect of the present invention is an image forming apparatus including an image forming apparatus main body, and a cartridge that is attachable to and detachable from the image forming apparatus main body and has a storage section for storing a developer, the image forming apparatus main body including an opening member having an opening, a biasing means, a light emitting section that emits light, a light receiving section that emits a detection signal according to a received light amount of light emitted by the light emitting section, and a pressing section, the detection unit being provided movably with respect to the opening member between a first position and a second position, positioned at the first position by the biasing force of the biasing means, and moved from the first position to the second position against the biasing force of the biasing means by pressing the pressing section, and a shielding member provided movably with respect to both the opening member and the detection unit between a third position and a fourth position, the cartridge being provided with a first light guiding section that guides the light from the light emitting section to an internal space of the storage section, and a shielding member provided movably with respect to both the opening member and the detection unit between a third position and a fourth position, the cartridge being provided with a first light guiding section that guides the light from the light emitting section to an internal space of the storage section, and a shielding member provided movably with respect to the internal space of the storage section. and a second light guiding portion that guides light that has passed between the light guiding portion and the light receiving portion to the light receiving portion, wherein when the cartridge is not attached to the image forming device main body, the detection unit is located at the first position and the shielding member is located at the third position, and when the cartridge is attached to the image forming device main body, the detection unit is located at the second position and the shielding member is located at the fourth position, and when the detection unit is located at the first position and the shielding member is located at the third position, at least a part of the light emitting portion or at least a part of the light receiving portion is located inside the opening and shielded by the shielding member when viewed in the optical axis direction of the light emitting portion, and when the detection unit is located at the second position and the shielding member is located at the fourth position, the light emitting portion and the first light guiding portion face each other through the opening, and the light receiving portion and the second light guiding portion face each other through the opening.

[0007] Another aspect of the present invention is an image forming apparatus including an image forming apparatus main body, and a cartridge that is attachable to and detachable from the image forming apparatus main body and has a storage section for storing a developer, wherein the image forming apparatus main body includes an opening member having an opening, a biasing means, a light emitting section that emits light, a light receiving section that emits a detection signal according to the amount of light received from the light emitting section, and a pressed section, the detection unit being movably provided with respect to the opening member between a first position and a second position, positioned at the first position by the biasing force of the biasing means, and moved from the first position to the second position against the biasing force of the biasing means by pressing the pressed section, and a shielding member being movably provided with respect to both the opening member and the detection unit between a third position and a fourth position, and when the cartridge is attached to the image forming apparatus main body, when the detection unit is located at the second position and the shielding member is located at the fourth position, when viewed in the optical axis direction of the light-emitting unit, the light-emitting unit and the light-receiving unit are located inside the opening and are not shielded by the shielding member, and when the detection unit is located at the second position and the shielding member is located at the fourth position, when viewed in the optical axis direction, the light-emitting unit and the light-receiving unit are located inside the opening and are not shielded by the shielding member, and the image forming device main body further has a control means capable of obtaining an amount of developer in the storage unit without using the detection unit. Effect of the Invention

[0008] According to the present invention, it is possible to provide a new technique for optically detecting the amount of developer. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of an image forming apparatus according to a first embodiment. [Diagram 2]1A is a perspective view of a process cartridge according to a first embodiment, FIG. 1B is an exploded view of a light guide and a light guide cover, and FIG. [Diagram 3] 2A and 2B are cross-sectional views for explaining the principle of remaining toner detection according to the first embodiment. [Figure 4] 1A is a perspective view of a detection device according to a first embodiment, and FIG. [Diagram 5] FIG. 2 is a diagram showing the inside of the device main body according to the first embodiment as viewed from above. [Figure 6] 1A to 1C are diagrams (a-1 to a-3, b-1 to b-3, c-1 to c-3) for explaining the operation of the detection device according to the first embodiment. [Figure 7] FIG. 11 is a perspective view of a process cartridge according to a modified example. [Figure 8] 1A is a perspective view of a detection device according to a second embodiment, FIG. 1B is an exploded view, FIG. 1C is a view showing a shutter and a frame, and FIG. [Figure 9] 11A to 11B are diagrams (a-1 to a-3, b-1 to b-4) for explaining the operation of the detection device according to the second embodiment. [Figure 10] 13A is a perspective view of a detection device according to a third embodiment, and FIG. 13B is an exploded view of a positioning guide, a shutter, and a shutter biasing spring. [Figure 11] 11A to 11B are diagrams (a-1 to a-3, b-1 to b-3) for explaining the operation of the detection device according to the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0011] First Embodiment An image forming apparatus according to a first embodiment will be described with reference to Figures 1 to 7. Below, the overall configuration of the image forming apparatus, a light transmission type remaining toner amount detection mechanism, a detection device in the apparatus main body, and the operation of the shutter in the detection device will be described in that order.

[0012] Image forming apparatus 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus 100 according to a first embodiment. The image forming apparatus 100 of this embodiment is a monochrome printer that forms a monochromatic image on a sheet S, which is a recording material, by an electrophotographic process.

[0013] The "image forming device" is not limited to a monochrome printer, but may be a color printer that forms a color image. The "image forming device" is not limited to a single-function printer that forms an image on a recording material based on image information (print data) received from the outside, but may be a copier with a copying function or a multifunction device with multiple functions. As the sheet S, which is the recording material (recording medium), various sheet materials of different sizes and materials can be used, such as paper such as plain paper and thick paper, sheet materials with surface treatments such as coated paper, sheet materials with special shapes such as envelopes and index paper, plastic films, cloth, etc.

[0014] The image forming apparatus 100 includes an apparatus main body 100A, which is the main body of the image forming apparatus, and a process cartridge 102 as a process unit. The process cartridge 102 can be attached to and detached from the apparatus main body 100A. The apparatus main body 100A refers to the portion of the image forming apparatus 100 excluding the process cartridge 102.

[0015] The apparatus main body 100A is provided with a mounting section 100B (mounting space) into which the process cartridge 102 is mounted. The image forming apparatus 100 can perform an image forming operation, which will be described later, by mounting the process cartridge 102 at a predetermined mounting position in the mounting section 100B. A user can mount and remove the process cartridge 102 by opening an opening / closing cover 19 of the apparatus main body 100A. The opening / closing cover 19 can be moved between a closed position that covers the mounting section 100B and the process cartridge 102, and an open position that exposes the mounting section 100B and the process cartridge 102 to the outside of the apparatus main body 100A.

[0016] The process cartridge 102 has a photosensitive drum 101 as an image carrier, a charging roller 103 as a charging means, and a developing unit 15 as a developing means. The photosensitive drum 101 has a cylindrical base made of aluminum or the like, and a photosensitive layer formed of a photoconductor such as an organic photoconductor (OPC) on the outer periphery of the base. The photosensitive drum 101 is rotatably supported at both ends in the rotation axis direction by a frame of the process cartridge 102. The photosensitive drum 101 is configured to be rotated by inputting a driving force from a driving source provided in the main body 100A of the apparatus to a driving input unit provided at one end in the rotation axis direction. The developing unit 15 includes a toner storage section 105 (developing container) that stores toner as a developer therein, and a developing roller 104 as a developer carrier that carries the developer and supplies it to the photosensitive drum 101.

[0017] In the following description, unless otherwise specified, the direction of the rotation axis of the photosensitive drum 101 when the process cartridge 102 is attached to the apparatus main body 100A is referred to as the longitudinal direction or simply the longitudinal direction of the photosensitive drum 101. Also, when describing a process cartridge 102 that is not attached to the apparatus main body 100A, the direction of the rotation axis of the photosensitive drum 101 is referred to as the longitudinal direction of the process cartridge 102 or simply the longitudinal direction.

[0018] The apparatus main body 100A includes a pickup roller 151, a feed roller 121, a separation roller 122, a conveying roller pair 131, an exposure unit 50 as an exposure means, a transfer roller 132, a fixing device 133, a discharge roller pair 134, and a control unit 200. In addition, a feed tray 152 on which sheets S are stacked is provided at the bottom of the apparatus main body 100A.

[0019] When image forming apparatus 100 receives an instruction to form an image together with image information (print data) from an external computer, for example, image forming apparatus 100 starts the image forming operation described below.

[0020] When the image forming operation is started, a toner image is created in the process cartridge 102. Specifically, the photosensitive drum 101 is rotationally driven in the direction of arrow A in the figure. A predetermined voltage is applied to the charging roller 103, which uniformly charges the surface of the photosensitive drum 101. The exposure unit 50 performs exposure by irradiating the photosensitive drum 101 with light (e.g., laser light) based on image information, and forms an electrostatic latent image on the surface of the photosensitive drum 101. The developing roller 104 supplies toner to the photosensitive drum 101, and develops the electrostatic latent image into a toner image.

[0021] In parallel with the creation of the toner image, sheets S are fed and conveyed one by one from a feed tray 152. The sheets S stacked on the feed tray 152 are brought into contact with a pickup roller 151 by the lifting of a middle plate (lift plate) supporting the lower surface of the sheet S. The uppermost sheet S is fed toward the feed roller 121 by the rotation of the pickup roller 151, and is further conveyed by the feed roller 121. The separation roller 122, which is in contact with the feed roller 121 to form a separation nip, applies a frictional force to the sheet S at the separation nip, thereby restricting the conveyance of sheets S other than the uppermost sheet S when multiple sheets S enter the separation nip.

[0022] The sheet S that has passed through the separation nip is transported to a transfer section where the photosensitive drum 101 faces a transfer roller 132 via a pair of transport rollers 131. In the transfer section, the toner image on the photosensitive drum 101 is transferred onto the sheet S by the transfer roller 132 to which a predetermined voltage is applied.

[0023] The sheet S onto which the toner image has been transferred is transported to a fixing device 133. The fixing device 133 heats the toner image on the sheet S with a heating means such as a halogen lamp or a ceramic heater while nipping and transporting the sheet S with a pair of fixing rollers. The toner image melts under heat and pressure in the nip portion of the pair of fixing rollers and then becomes fixed, thereby obtaining an image fixed on the sheet S. The sheet S that has passed through the fixing device 133 is discharged outside the image forming apparatus 100 by a pair of discharge rollers 134 and stacked on a discharge tray 150.

[0024] The control unit 200 is an example of a control means for controlling the operation of the image forming apparatus 100. The control unit 200 includes a CPU and a storage unit such as a ROM and a RAM. The CPU reads out a program from the ROM and executes it to control the operation of the image forming apparatus 100. For example, the CPU notifies a user of information requesting replacement of a process cartridge based on the result of detection of the remaining toner amount using a detection device 400 described later or the result of detection of the remaining toner amount by a method not using the detection device 400. The method of notification is not particularly limited, and may include displaying an image on a display unit (such as a liquid crystal panel) included in the apparatus main body 100A, sending a notification to an external computer connected to the image forming apparatus 100, etc.

[0025] <Light transmission type toner remaining amount detection mechanism> The configuration of the process cartridge 102 with respect to optical detection of the remaining toner amount (developer amount) will be described with reference to Figures 2(a) to (c). Figure 2(a) is a perspective view of the process cartridge 102. Figure 2(b) is an exploded view of a light guide 410 and a light guide cover 420 provided in the process cartridge 102. Figure 2(c) is a cross-sectional view of the light guide 410 taken along line cc in Figure 2(b).

[0026] As shown in Fig. 2(a), the developing unit 15, which is a part of the process cartridge 102, includes a light guide 410 and a light guide cover 420 that covers a part of the light guide 410. The light guide 410 is attached to the toner storage section 105 of the developing unit 15 so as to cover an opening provided in a wall surface of the toner storage section 105. The light guide 410 is a light guiding member that guides light (hereinafter referred to as detection light) emitted by a light emitting element 451a of a detection device 400 (Fig. 4(b)), which will be described later.

[0027] Although details will be described later, the apparatus main body 100A is provided with a detection device 400 including a light emitting element 451a and a light receiving element 451b as shown in Figures 4(a and 4b). The image forming apparatus 100 in this embodiment has a toner remaining amount detection mechanism including the detection device 400 of the apparatus main body 100A, and a light guide 410 and a light guide cover 420 of the process cartridge 102.

[0028] As shown in FIG. 2(b), the light guide 410 includes a first light guiding section 410a (input side light guiding section), a second light guiding section 410b (output side light guiding section), and a window section 410c. The first light guiding section 410a guides the detection light L emitted by the light emitting element 451a (FIG. 4(b)) of the detection device 400 to a spatial light path L1 (FIG. 2(c)) passing through the internal space of the toner storage section 105. The second light guiding section 410b guides the detection light L incident from the spatial light path L1 to the light receiving element 451b (FIG. 4(b)) of the detection device 400. The window section 410c is formed in a substantially rectangular shape so as to cover the opening of the toner storage section 105. The window section 410c is fixed to the toner storage section 105 at the periphery of the opening of the toner storage section 105 by a method such as welding or adhesion.

[0029] As shown in FIG. 2(b, c), the first light guiding section 410a has a first surface a1 on which the detection light L from the light emitting element 451a is incident, and a second surface a2 on which the detection light L is emitted to a spatial light path L1 in the toner storage section 105. The first surface a1 is located outside the toner storage section 105, and the second surface a2 is located inside the toner storage section 105. In a state in which the process cartridge 102 is mounted in the apparatus main body 100A, the first surface a1 faces the light emitting element 451a through a detection opening 457a of the apparatus main body 100A, which will be described later. The first surface a1 is an example of a light input section through which the detection light L from the light emitting element 451a of the apparatus main body 100A is input to the process cartridge 102 in a light transmission type remaining toner detection mechanism.

[0030] The second light guiding section 410b has a third surface b3 on which the detection light L is incident from the spatial optical path L1, and a fourth surface b4 from which the detection light L is emitted toward the light receiving element 451b. The third surface b3 is located inside the toner storage section 105, and the fourth surface b4 is located outside the toner storage section 105. Inside the toner storage section 105, the third surface b3 of the second light guiding section 410b faces the second surface a2 of the first light guiding section 410a across the spatial optical path L1. When the process cartridge 102 is mounted in the apparatus main body 100A, the fourth surface b4 faces the light receiving element 451b through the detection opening 457b of the apparatus main body 100A. The fourth surface b4 is an example of a light output section that outputs the detection light L from the process cartridge 102 toward the light receiving element 451b of the apparatus main body 100A in a light transmission type toner remaining amount detection mechanism.

[0031] When the process cartridge 102 is attached to the apparatus main body 100A, the detection light L emitted from the light emitting element 451a of the detection device 400 included in the apparatus main body 100A is incident on the first surface a1 of the light guide 410 included in the process cartridge 102. The detection light L travels inside the first light guiding section 410a, exits from the second surface a2 into the toner storage section 105, passes through the spatial light path L1, and enters the third surface b3 of the second light guiding section 410b. The detection light L further travels inside the second light guiding section 410b, exits from the fourth surface b4, and enters the light receiving element 451b of the apparatus main body 100A. The light receiving element 451b emits a detection signal according to the amount of the incident detection light L.

[0032] The traveling path of the detection light L may be reversed from that described above. That is, the detection light L from the light-emitting element 451a may be incident on the fourth surface b4 of the second light guiding unit 410b, pass through the spatial light path L1, and exit from the first surface a1 of the first light guiding unit 410a toward the light-receiving element 451b.

[0033] The first surface a1 of the first light guiding section 410a and the fourth surface b4 of the second light guiding section 410b are provided at one end of the process cartridge 102 in the longitudinal direction (FIG. 2(a)). The detection device 400 of the apparatus main body 100A is provided at one end in the longitudinal direction with respect to the mounting section 100B in which the process cartridge 102 is mounted (FIG. 5). In other words, the position where the detection light L is input from the apparatus main body 100A to the process cartridge 102 and the position where the detection light L is output from the process cartridge 102 to the apparatus main body 100A are located at one end in the longitudinal direction with respect to the process cartridge 102. With this configuration, the detection device 400 and the components (wiring, etc.) attached to the detection device 400 can be concentrated at one end in the longitudinal direction with respect to the apparatus main body 100A.

[0034] In this embodiment, the second surface a2 of the first light guiding portion 410a is disposed at a position closer to the center position of the process cartridge 102 in the longitudinal direction than the first surface a1. Also, in this embodiment, the third surface b3 of the second light guiding portion 410b is disposed at a position closer to the center position of the process cartridge 102 in the longitudinal direction than the fourth surface b4. In other words, the spatial light path L1 in the toner storage portion 105 is disposed closer to the center of the process cartridge 102 than the position where the input and output of the detection light L is performed between the apparatus main body 100A and the process cartridge 102. With this configuration, the remaining toner amount detection is less susceptible to the influence of toner bias in the longitudinal direction in the toner storage portion 105.

[0035] The first light guiding portion 410a has a portion extending along the longitudinal direction at least partially between the first surface a1 and the second surface a2. The second light guiding portion 410b has a portion extending along the longitudinal direction at least partially between the third surface b3 and the fourth surface b4.

[0036] The light guide 410 may be an integrally molded product made of a resin material that transmits the detection light. However, the light guide 410 is not limited to being an integrally molded product, and for example, the first light guiding portion 410a, the second light guiding portion 410b, and the window portion 410c may be separate parts.

[0037] As shown in FIG. 2(b), the light guide cover 420 has a first positioning portion 420a for positioning the first light guiding portion 410a of the light guide 410 and a second positioning portion 420b for positioning the second light guiding portion 410b of the light guide 410. The light guide cover 420 is an example of a cover member that fits with the first light guiding portion 410a and the second light guiding portion 410b of the light guide 410. The first positioning portion 420a is a hole shape (rectangular hole) that fits with a columnar portion (a quadrangular columnar portion in the illustrated example) including the first surface a1 of the first light guiding portion 410a. The second positioning portion 420b is a hole shape (round hole) that fits with a columnar portion (a cylindrical portion in the illustrated example) including the fourth surface b4 of the second light guiding portion 410b.

[0038] The light guide cover 420 is positioned relative to the frame of the process cartridge 102. In addition, the first surface a1 and the fourth surface b4 of the light guide 410 are positioned relative to the frame of the process cartridge 102 by the light guide cover 420. The light guide cover 420 is preferably formed of a flame-retardant material having a high resin density, for example.

[0039] A method for detecting the remaining amount of toner will be described with reference to Figures 3(a) and 3(b). Figures 3(a) and 3(b) are cross-sectional views of the toner storage section 105 of the developing unit 15 cut along a plane perpendicular to the longitudinal direction and passing through the light guide 410.

[0040] An agitating member 154 for agitating the toner 20 is provided inside the toner storage unit 105. The agitating member 154 has a shaft portion 154a extending in the longitudinal direction and a blade portion 154b protruding from the shaft portion 154a in a direction intersecting the longitudinal direction. The agitating member 154 rotates about the shaft portion 154a by a driving force input from a driving source provided in the apparatus main body 100A, and agitates the toner 20 in the toner storage unit 105 by the blade portion 154b.

[0041] When the toner 20 lifted by the stirring member 154 reaches the spatial optical path L1 formed by the light guide 410, the detection light L is blocked by the toner 20. In other words, the light receiving element 451b of the detection device 400 emits a signal indicating that it is not receiving the detection light L. The length of time that the detection light L is blocked during one rotation of the stirring member 154 changes depending on the amount of toner 20 in the toner storage unit 105.

[0042] The control unit 200 (FIG. 1) of the apparatus main body 100A can detect the amount of toner 20 in the toner storage unit 105 when the process cartridge 102 is attached to the apparatus main body 100A and the stirring member 154 is driven. The control unit 200 calculates the amount of toner 20 in the toner storage unit 105 based on, for example, the rotation period of the stirring member 154 and the length of the period during which the detection light L is blocked during the rotation period.

[0043] Detection Device Next, the configuration of the detection device 400 according to this embodiment will be described with reference to Figures 4(a, b) and 5. Figure 4(a) is a perspective view of the detection device 400. Figure 4(b) is an exploded view of the detection device 400. Figure 5 is a diagram showing the mounting position of the detection device 400, and is a diagram showing the inside of the device main body 100A as viewed from above.

[0044] In the following description and in each drawing, a first direction related to the detection device 400 is referred to as the "X direction", and a second direction perpendicular to the X direction is referred to as the "Y direction". A direction perpendicular to both the X direction and the Y direction is referred to as the "Z direction". In the following description and in each drawing, the "-X direction", "-Y direction", and "-Z direction" respectively indicate the directions opposite to the directions of the arrows illustrated as the X direction, Y direction, and Z direction.

[0045] In this embodiment, the X direction is a direction substantially parallel to the longitudinal direction of the photosensitive drum 101. In this embodiment, the Y direction is a direction along the mounting direction D (FIG. 2(a)) of the process cartridge 102 to the apparatus main body 100A. In this embodiment, the Y direction is a direction substantially parallel to the movement direction of the process cartridge 102 when the process cartridge 102 is mounted to the apparatus main body 100A.

[0046] 4(a, b), the detection device 400 has a sensor substrate 451, a substrate holder 450, a positioning guide 455, a shutter 456, and a biasing spring 454 (FIG. 5). The sensor substrate 451 includes a substrate 451c, and a light emitting element 451a and a light receiving element 451b arranged on the substrate 451c. The detection device 400 is supported by a frame 457 which is a part of the frame of the device main body 100A.

[0047] In the detection device 400, the sensor substrate 451, the substrate holder 450, and the positioning guide 455 are configured to move integrally with respect to the frame 457. Hereinafter, the sensor substrate 451, the substrate holder 450, and the positioning guide 455 are collectively referred to as the "sensor unit 400A." The sensor unit 400A is an example of a detection unit.

[0048] The sensor unit 400A is movable between a non-detection position (first position, standby position) and a detection position (second position). The non-detection position (first position) is a position where the sensor unit 400A is not used to detect the remaining amount of toner. The detection position (second position) is a position for detecting the remaining amount of toner in the process cartridge 102 using the sensor unit 400A. The non-detection position (first position) is a position of the sensor unit 400A when the process cartridge 102 is not attached to the apparatus main body 100A. The detection position (second position) is a position of the sensor unit 400A when the process cartridge 102 is attached to the apparatus main body 100A.

[0049] The optical axis direction of the light emitting element 451a is a direction intersecting (preferably perpendicular to) both the X direction and the Y direction. In this embodiment, the optical axis direction of the light emitting element 451a is substantially parallel to the Z direction. However, the optical axis direction of the light emitting element 451a may be set to a direction intersecting obliquely with the normal direction of the substrate 451c by, for example, attaching the directional light emitting element 451a obliquely with respect to the substrate 451c.

[0050] The sensor substrate 451 has a light emitting element 451a as a light emitting section and a light receiving element 451b as a light receiving section. An example of the light emitting element 451a is an LED, and an example of the light receiving element 451b is a phototransistor, but other elements may be used. In the following description, the light emitting element 451a and the light receiving element 451b may be collectively referred to as a detection element.

[0051] As described above, the direction of the detection light L in the remaining toner detection mechanism may be opposite to that shown in FIG. 2B. In that case, the positions of the light-emitting element 451a and the light-receiving element 451b may be interchanged. Therefore, the configuration of the detection device 400 described below is also useful in a modified example in which the positions of the light-emitting element 451a and the light-receiving element 451b are interchanged.

[0052] The substrate holder 450 is an example of a holding member that holds the sensor substrate 451. The sensor substrate 451 is fixed to the substrate holder 450 by a method such as snap fitting, screw fastening, or adhesive, and moves together with the substrate holder 450.

[0053] The positioning guide 455 has contact portions 455a, 455b (FIGS. 6(a-1) and (a-3)) as pressed portions, and protrusions 455c, 455d. The positioning guide 455 is a guide member for positioning the sensor unit 400A when the process cartridge 102 is attached. The sensor unit 400A is configured to move from the non-detection position to the detection position by pressing the contact portions 455a, 455b when the process cartridge 102 is attached, and to be positioned (held) at the detection position.

[0054] The contact portions 455a and 455b of this embodiment are arranged so as to be pressed against the light guide cover 420 of the process cartridge 102. The contact portion 455a has a surface extending along the X direction. The contact portion 455b has a surface extending along the Y direction and is arranged in an L-shape with respect to the contact portion 455a. The contact portion 455a is an example of a first force receiving portion that receives a pressing force in a first direction intersecting with the optical axis direction of the light emitting element 451a. The contact portion 455b is an example of a second force receiving portion that receives a pressing force in a second direction intersecting with both the optical axis direction and the first direction. Here, examples of the first direction and the second direction are the Y direction and the X direction, respectively.

[0055] The protrusions 455c and 455d protrude in a direction intersecting (preferably perpendicular to) both the X direction and the Y direction. The protrusions 455c and 455d are fitted into holes in the substrate holder 450. As a result, the positioning guide 455 is connected to the substrate holder 450 and the sensor substrate 451 held by the substrate holder 450 so as to move integrally with the substrate holder 450. That is, the protrusions 455c and 455d function as a connecting portion connecting the positioning guide 455 and the substrate holder 450. Note that the connecting portion may be, for example, a member formed integrally with the substrate holder 450 and engaged with the positioning guide 455. In addition, in this embodiment, one protrusion 455c also serves as an engaging portion that engages with the shutter 456, but the sensor unit 400A may be provided with an engaging portion as a separate member from the protrusions 455c and 455d.

[0056] The shutter 456 is an example of a shielding member (opening / closing member) that is movable relative to both the frame 457 and the sensor unit 400A. The shutter 456 is movable between a shielding position (third position) and an exposed position (fourth position, retracted position). The shielding position (third position) is the position of the shutter 456 when the process cartridge 102 is not attached to the apparatus main body 100A. The exposed position (fourth position) is the position of the shutter 456 when the process cartridge 102 is attached to the apparatus main body 100A.

[0057] The shutter 456 of this embodiment has a shielding portion 456c, a support shaft 456a, and a guide portion 456b. The shutter 456 is provided movably with respect to a frame 457 (aperture member) as an aperture member in which detection openings 457a and 457b are provided. The detection opening 457a is a hole (first hole) corresponding to the light emitting element 451a. The detection opening 457b is a hole (second hole) corresponding to the light receiving element 451b. Note that the detection openings 457a and 457b can be formed as one opening (hole shape or slit) by communicating with each other.

[0058] The shielding portion 456c is a portion that covers the detection elements (451a, 451b) of the sensor board 451. In this embodiment, as described later, in a state before the process cartridge 102 is attached, the shielding portion 456c is configured to cover the light emitting element 451a and the light receiving element 451b.

[0059] The support shaft 456a is rotatably supported by the frame of the apparatus main body 100A. In this embodiment, the support shaft 456a is supported by a bearing portion 449a of a positioning member 449 (FIG. 5) described later. The direction of the rotation axis of the shutter 456 intersects (preferably perpendicular to) both the X direction and the Y direction. In this embodiment, the shutter 456 moves between the shielding position and the exposing position by rotating about the support shaft 456a with respect to the frame 457.

[0060] The guide portion 456b is an example of an engaged portion that is engaged with the protrusion portion 455c as an engaging portion of the sensor unit 400A. The guide portion 456b in this embodiment has a groove shape into which the protrusion portion 455c fits. The engagement between the protrusion portion 455c and the guide portion 456b positions the shutter 456 according to the position of the sensor unit 400A. Specifically, when the sensor unit 400A is located at the non-detection position, the shutter 456 is positioned at the shielding position. When the sensor unit 400A is located at the detection position, the shutter 456 is positioned at the exposure position. Also, the shutter 456 moves in conjunction with the movement of the sensor unit 400A when the process cartridge 102 is attached.

[0061] Detection openings 457a, 457b and through holes 457c, 457d are formed in the frame 457. The detection opening 457a is an opening through which the detection light L from the light emitting element 451a toward the light guide 410 passes when the remaining amount of toner is detected. The detection opening 457b is an opening through which the detection light L from the light guide 410 toward the light receiving element 451b passes when the remaining amount of toner is detected. The frame 457 is an example of an opening member provided with the detection openings 457a, 457b.

[0062] The through holes 457c and 457d are holes through which the protrusions 455c and 455d of the positioning guide 455 are inserted, respectively. The through holes 457c and 457d are formed to be larger than the cross-sectional area of ​​the protrusions 455c and 455d so as to allow the positioning guide 455 to move when the process cartridge 102, which will be described later, is attached (FIG. 6(b-1)).

[0063] In this embodiment, the positioning guide 455 and the substrate holder 450 are connected via the protrusions 455c and 455d that penetrate the through holes 457c and 457d. This allows the sensor substrate 451 to be positioned by the positioning guide 455 that is arranged on the opposite side (the lower surface side in FIG. 4(b)) to the side on which the sensor substrate 451 is arranged (the upper surface side in FIG. 4(b)) with respect to the frame 457.

[0064] In the present embodiment, the positioning guide 455 of the detection device 400 that abuts against the light guide cover 420 is disposed on the inner surface side of the frame 457. The inner surface side of the frame 457 is the side of the mounting portion 100B where the process cartridge 102 is mounted to the frame 457 (second side, in the present embodiment, the Z direction side), and is the opposite side to the outer surface side of the frame 457 (first side, in the present embodiment, the -Z direction side). In the detection device 400, the sensor board 451 and the board holder 450 are disposed on the outer surface side of the frame 457. The shutter 456 is disposed on the outer surface side of the frame 457, in a space between the frame 457 and the sensor board 451 and the board holder 450. Since the shutter 456 is disposed on the outer surface side (first side) of the frame 457 (opening member), it is possible to prevent the hand of a user or the like from unintentionally contacting the shutter 456 from the space on the inner surface side of the frame 457, for example.

[0065] As shown in Fig. 5, the detection device 400 is disposed next to the exposure unit 50 in the X direction. The exposure unit 50 is disposed on the upper surface side (outer surface side) of a frame 457 that extends in the longitudinal direction so as to connect the left and right side plates of the apparatus main body 100A. The detection device 400 is biased by a biasing spring 454 as a biasing means. The biasing spring 454 in this embodiment is a tension spring. One end of the biasing spring 454 is attached to a positioning member 449 fixed to the outer surface of the frame 457, and the other end of the biasing spring 454 is attached to the substrate holder 450.

[0066] The biasing force F1 of the biasing spring 454 acts in an oblique direction that is the -X direction and the -Y direction. The positioning member 449 has an abutting portion 449c against which an end 450c in the -X direction of the substrate holder 450 abuts, and an abutting portion 449b against which an end 450b in the -Y direction of the substrate holder 450 abuts.

[0067] When the process cartridge 102 is not attached to the apparatus main body 100A, the substrate holder 450 abuts against the abutment portions 449b and 449c by the biasing force F1 in the -X and -Y directions, and the sensor unit 400A is positioned at the non-detection position. The abutment portion 449b is an example of a first abutment portion against which the detection unit abuts in the opposite direction (-Y direction) of the first direction. The abutment portion 449c is an example of a second abutment portion against which the detection unit abuts in the opposite direction (-X direction) of the second direction. In other words, when the first force receiving portion and the second force receiving portion of the detection unit are not receiving a pressing force, the detection unit is positioned at the first position in a state where it abuts against the first abutment portion and the second abutment portion by the biasing force of the biasing means.

[0068] <Operation when installing cartridge> Next, the operation of the detection device 400 when the process cartridge 102 is mounted in the apparatus main body 100A will be described with reference to each diagram in FIG.

[0069] 6A-1 to 6A-3 are views of the positioning guide 455 of the detection device 400 and the light guide cover 420 of the process cartridge 102 as viewed from the -Z direction. FIG. 6B-1 to 6B-3 are views of the detection openings 457a, 457b and the detection elements (451a, 451b) of the detection device 400 and the first light guiding portion 410a and the second light guiding portion 410b of the light guide 410 of the process cartridge 102 as viewed from the Z direction. FIG. 6C-1 to 6C-3 are views of the shutter 456, the sensor board 451, and the board holder 450 of the detection device 400 as viewed from the Z direction. In each of the views of FIG. 6, elements other than those described above among the components of the toner remaining amount detection mechanism in this embodiment are omitted from the illustration.

[0070] 6(a-1), (b-1), and (c-1) show the state of the detection device 400 before the cartridge is mounted, i.e., before the process cartridge 102 is mounted to the main body 100A of the apparatus. In addition, in FIG. 6(a-1) and (b-1), the light guide cover 420 and the light guide 410 are also shown in the middle of mounting the process cartridge 102 to the main body 100A of the apparatus and before the light guide cover 420 comes into contact with the positioning guide 455. FIG. 6(a-2), (b-2), and (c-2) show the state in the middle of mounting the cartridge, i.e., in the middle of mounting the process cartridge 102 to the main body 100A of the apparatus and after the light guide cover 420 comes into contact with the positioning guide 455. FIG. 6(a-3), (b-3), and (c-3) show the state after the cartridge is mounted, i.e., after the process cartridge 102 is mounted to the main body 100A of the apparatus.

[0071] 6(a-1), (b-1), and (c-1), in the state before the cartridge is mounted, sensor unit 400A is positioned at the non-detection position by the biasing force F1 of biasing spring 454. In addition, since sensor unit 400A is positioned at the non-detection position, shutter 456 is positioned at the blocking position.

[0072] As shown in FIG. 6(b-1)(c-1), when viewed from the Z direction in a state before the cartridge is mounted, at least a part of the opening area of ​​the detection openings 457a and 457b is covered by the shutter 456. "When viewed from the Z direction" refers to the state of the device when the target is viewed from the Z direction side toward the -Z direction, that is, in this embodiment, when the target is viewed in the optical axis direction of the light-emitting unit 200a. Also, when viewed from the Z direction in a state before the cartridge is mounted, at least a part of the light-emitting element 451a or at least a part of the light-receiving element 451b is located inside the opening area of ​​the detection openings 457a and 457b while being shielded by the shutter 456. In this embodiment, a part of the light-emitting element 451a and a part of the light-receiving element 451b are located inside the opening area of ​​the detection openings 457a and 457b and are shielded by the shutter 456. The remaining part of the light-emitting element 451 a and the remaining part of the light-receiving element 451 b are located outside the opening areas of the detection openings 457 a and 457 b and are shielded by the frame 457 .

[0073] In this manner, before the cartridge is mounted, the shutter 456 shields the detection elements (451a, 451b) so that the detection elements (451a, 451b) are not exposed through the detection openings 457a, 457b. This protects the detection elements (451a, 451b) from contamination such as toner and dust scattered from the process cartridge 102, for example, and suppresses a decrease in detection accuracy due to the adhesion of contamination.

[0074] As shown in Fig. 6(a-1), in a state before the cartridge is mounted, the positioning guide 455 is in a positional relationship where it interferes with the light guide cover 420 of the process cartridge 102 inserted into the apparatus main body 100A in the X and Y directions. That is, the contact portion 455b of the positioning guide 455 protrudes in the -X direction from the contact portion 420c, which is the end portion on the X direction side of the light guide cover 420 (Fig. 6(a-1)). Also, the contact portion 455a of the positioning guide 455 protrudes in the -Y direction from the position of the contact portion 420d, which is the end portion on the Y direction side of the light guide cover 420, in a state after the cartridge is mounted (Fig. 6(a-3)).

[0075] As shown in FIGS. 6(a-2) and (a-3), when the process cartridge 102 is inserted in the mounting direction D, the positioning guide 455 is pressed against the light guide cover 420, causing the sensor unit 400A to move in the movement direction M1.

[0076] More specifically, as shown in Fig. 6(a-2), during cartridge installation, the contact portion 420c of the light guide cover 420 contacts the contact portion 455b of the positioning guide 455. By pressing the contact portion 455b, the end portion of the positioning guide 455 on the -Y direction side moves in the X direction, and the sensor unit 400A becomes tilted. In addition, in conjunction with the movement of the sensor unit 400A, the shutter 456 starts to move (Fig. 6(c-2)).

[0077] In addition, it is preferable to provide a tapered portion inclined toward the X direction side in the -Y direction at the end of the abutting portion 455b in the -Y direction. This allows the light guide cover 420 to abut against the tapered portion, thereby making it possible to move the main body of the detection device 400 more smoothly.

[0078] 6(a-2), when the process cartridge 102 is further inserted in the mounting direction D, as shown in FIG. 6(a-3), the abutment portion 420d of the light guide cover 420 abuts against the abutment portion 455a of the positioning guide 455. The abutment portion 455a of the positioning guide 455 is pressed against the abutment portion 420d of the light guide cover 420, causing the sensor unit 400A to move in the Y direction.

[0079] When the process cartridge 102 reaches a predetermined mounting position, the sensor unit 400A is positioned at the detection position with the contact portions 455a and 455b of the positioning guide 455 contacting the contact portions 420c and 420d of the light guide cover 420. The detection position is a position obtained by moving obliquely in the X and Y directions from the non-detection position (FIG. 6(a-1)). In other words, the movement direction M1 in which the sensor unit 400A moves from the non-detection position to the detection position is opposite to the direction of the biasing force F1 of the biasing spring 454 in the X direction and opposite to the direction of the biasing force F1 of the biasing spring 454 in the Y direction.

[0080] In this manner, the sensor unit 400A is moved against the biasing force F1 of the biasing spring 454 by the force received from the process cartridge 102 when the process cartridge 102 is attached, and thereby moves from the non-detection position to the detection position.

[0081] Also, as the sensor unit 400A moves to the detection position, the shutter 456 moves to the exposed position (FIG. 6(c-3)). In this embodiment, as the protrusion 455c of the positioning guide 455 moves, the guide portion 456b of the shutter 456 is pressed by the protrusion 455c, and the shutter 456 moves (rotates) in the moving direction M2 around the support shaft 456a. As a result, the shutter 456 retreats to the exposed position where the shielding portion 456c does not cover the light emitting element 451a and the light receiving element 451b.

[0082] The movement direction M2 of the shutter 456 when moving from the shielded position to the exposed position is different from the movement direction M1 of the sensor unit 400A when moving from the non-detection position to the detection position. By providing the shutter 456 that moves in a direction different from that of the sensor unit 400A, it is possible to provide a specific configuration that allows the device main body 100A to be miniaturized, as described later.

[0083] Also, when viewed from the Z direction in the state before the cartridge is mounted (FIG. 6(c-1)), the distance from the rotation center of the shutter 456 to the light emitting element 451a and the distance from the rotation center to the light receiving element 451b are both longer than the distance from the rotation center to the protrusion 455c. This ensures that the movement amount of the part of the shutter 456 that covers the detection elements (451a, 451b) can be secured even if the movement amount of the protrusion 455c (the movement amount of the sensor unit 400A) is shortened. In other words, it becomes easy to realize a state in which the detection element is sufficiently shielded and a state in which it is sufficiently exposed. The distance from the rotation center of the shutter 456 to the protrusion 455c is based on the maximum value of the distance from the rotation center of the shutter 456 to the protrusion 455c during the period from before the process cartridge 102 is mounted to after the process cartridge 102 is mounted.

[0084] Also, guide portion 456b is formed in a groove shape into which protrusion 455c fits. Therefore, the distance from protrusion 455c to the center of rotation of shutter 456 is allowed to change as sensor unit 400A moves.

[0085] 6(a-3), (b-3), and (c-3) after the cartridge is mounted, sensor unit 400A is positioned at the detection position. In addition, since sensor unit 400A is positioned at the detection position, shutter 456 is positioned at the exposure position.

[0086] As shown in Fig. 6(b-3) and (c-3), when viewed from the Z direction in a state after the cartridge is mounted, the light emitting element 451a and the light receiving element 451b are not covered by the shutter 456 and are exposed inside the detection openings 457a and 457b. Also, in a state after the cartridge is mounted, the light emitting element 451a faces the first light guiding portion 410a of the light guide 410 through the detection opening 457a, and the light receiving element 451b faces the second light guiding portion 410b of the light guide 410 through the detection opening 457b. In other words, in a state after the cartridge is mounted, the detection elements (451a and 451b) face the light input portion (first surface a1, Fig. 2(b)) and the light output portion (fourth surface b4) on the process cartridge 102 side through the detection openings 457a and 457b.

[0087] Therefore, an optical path is formed in which the detection light L emitted by the light-emitting element 451a is emitted to a spatial optical path L1 (FIG. 2(c)) in the process cartridge 102 through the first light-guiding portion 410a and is incident on the light-receiving element 451b through the second light-guiding portion 410b. Therefore, after the cartridge is mounted, the detection device 400 is in a state in which it can detect the remaining amount of toner in the process cartridge 102 using the detection light L emitted by the light-emitting element 451a. In other words, the control unit 200 of the apparatus main body 100A can obtain the remaining amount of toner in the process cartridge 102 based on the detection signal from the detection device 400.

[0088] In this embodiment, the positioning guide 455 comes into contact with the light guide cover 420 during the process of mounting the process cartridge 102 to the apparatus main body 100A, so that the sensor unit 400A is positioned with respect to the light guide cover 420. In other words, after the cartridge is mounted, the light emitting element 451a and the light receiving element 451b of the sensor unit 400A are positioned with reference to the light guide cover 420 engaged with the light guide 410.

[0089] This configuration can improve the accuracy of detecting the remaining toner amount by the detection device 400. Suppose that the positions of the light emitting element 451a and the light receiving element 451b are fixed regardless of whether the process cartridge 102 is attached or detached. In this case, due to factors such as manufacturing tolerances and assembly tolerances of parts, the relative positions between the light emitting element 451a and the light receiving element 451b of the apparatus main body 100A and the light guide 410 of the process cartridge 102 may vary after the cartridge is attached. This variation in relative position may cause a decrease in the amount of light received by the light receiving element 451b. For example, if the distance between the light emitting element 451a and the light receiving element 451b and the first surface a1 and the fourth surface b4 of the light guide 410 increases, the amount of light received may decrease. In contrast, in this embodiment, the light-emitting element 451a and the light-receiving element 451b are positioned based on the light guide cover 420, so that the amount of light received by the light-receiving element 451b can be made more stable, thereby improving the accuracy of detecting the remaining toner amount.

[0090] When the process cartridge 102 is removed from the apparatus main body 100A, the detection device 400 operates in the reverse process to the above-mentioned operation. That is, when the light guide cover 420 is released from the positioning guide 455, the sensor unit 400A slides in the opposite direction to the moving direction M1 according to the biasing force F1 of the biasing spring 454, and moves from the detection position to the non-detection position. In addition, in conjunction with the movement of the sensor unit 400A, the shutter 456 rotates in the opposite direction to the moving direction M2, and moves from the exposed position to the shielded position. As a result, the light emitting element 451a and the light receiving element 451b can be protected by the shutter 456 after the process cartridge 102 is removed.

[0091] Advantages of this embodiment As described above, the device body 100A of this embodiment includes the sensor unit 400A that can move between the non-detection position and the detection position, and the shutter 456 that can move between the shielding position and the exposure position. When the sensor unit 400A is located at the non-detection position and the shutter 456 is located at the shielding position, at least a part of the light-emitting element 451a or at least a part of the light-receiving element 451b is located inside the detection openings 457a and 457b and is covered by the shutter 456 when viewed from the Z direction (FIG. 6(b-1)). Also, when the sensor unit 400A is located at the detection position and the shutter 456 is located at the exposure position, the light-emitting element 451a and the light-receiving element 451b are exposed inside the detection openings 457a and 457b when viewed from the Z direction (FIG. 6(b-3)).

[0092] That is, when the detection unit is located at the first position and the shielding member is located at the third position, at least a part of the light-emitting unit or at least a part of the light-receiving unit is located inside the opening while being shielded by the shielding member when viewed in the optical axis direction of the light-emitting unit, and when the detection unit is located at the second position and the shielding member is located at the fourth position, the light-emitting unit and the light-receiving unit are located inside the opening without being shielded by the shielding member when viewed in the optical axis direction.

[0093] According to this configuration, the light emitting element 451a and the light receiving element 451b can be switched between a state in which they are shielded from the detection openings 457a and 457b and a state in which they are exposed to the detection openings 457a and 457b while keeping the movement amount of the sensor unit 400A small. Specifically, as a comparative example of this embodiment, a configuration in which the shutter 456 is not provided is assumed. In this case, it is considered that the non-detection position of the sensor unit 400A is set at a position farther away from the detection position than the non-detection position of this embodiment, and the light emitting element 451a and the light receiving element 451b are positioned outside the detection openings 457a and 457b. As a result, when the sensor unit 400A is located at the non-detection position, the light emitting element 451a and the light receiving element 451b are shielded by the frame 457. However, in this comparative example, if the non-detection position is set so that the light emitting element 451a and the light receiving element 451b are sufficiently shielded by the frame 457, the movement distance between the detection position and the non-detection position becomes longer than in this embodiment. Therefore, a large space is required for arranging the sensor unit 400A, which leads to an increase in size of the apparatus main body 100A.

[0094] In contrast, according to the configuration of this embodiment, by moving both the sensor unit 400A and the shutter 456, it is possible to switch between a state in which the light emitting element 451a and the light receiving element 451b are shielded and a state in which both elements are exposed. Therefore, it is possible to realize a state in which the light emitting element 451a and the light receiving element 451b are shielded and a state in which both elements are exposed while shortening the moving distance of the sensor unit 400A. In other words, according to this embodiment, it is possible to reduce the space required for the toner remaining amount detection mechanism, and to reduce the size of the apparatus main body 100A.

[0095] Furthermore, according to the configuration of this embodiment, in the image forming apparatus 100 including the apparatus main body 100A and the process cartridge 102, it is possible to reduce the space required for the toner remaining amount detection mechanism and to reduce the size of the image forming apparatus 100. The process cartridge 102 here is a cartridge (first cartridge) including a light guide 410 and the like which together with the detection device 400 of the apparatus main body 100A constitute a light transmission type toner remaining amount detection mechanism.

[0096] (Modification) As a modified example, an image forming apparatus in which a process cartridge 102A (second cartridge) that does not have a configuration for detecting the amount of remaining toner by light transmission is mounted on the image forming apparatus main body (apparatus main body 100A) common to the first embodiment will be described. In this embodiment, the configuration for detecting the amount of remaining toner by light transmission refers to a light guide 410 and a light guide cover 420. The configuration of the apparatus main body 100A is the same as that of the first embodiment, so a description thereof will be omitted.

[0097] 7 is a perspective view of a process cartridge 102A according to a modified example. The process cartridge 102A can be mounted in the apparatus main body 100A in place of the process cartridge 102 (FIG. 2(a)) of the first embodiment. In a state in which the process cartridge 102A is mounted in the apparatus main body 100A, the image forming apparatus can perform an image forming operation using the process cartridge 102A.

[0098] When the process cartridge 102A is attached to the apparatus main body 100A, the control unit 200 of the apparatus main body 100A detects the amount of toner remaining inside the process cartridge 102A by a toner remaining amount detection means other than the light transmission type. In other words, the image forming apparatus main body of this embodiment has a control means capable of acquiring the amount of developer inside the toner storage portion 105 (inside the storage portion) of the process cartridge 102 without using the detection unit.

[0099] For example, the control unit 200 can calculate the toner consumption and the current remaining amount of toner using a pixel count method. In the pixel count method, an estimated value of the toner consumption is calculated based on the amount of toner consumed per pixel and the integrated value (pixel count) of the number of pixels forming an image based on image information (print data) input to the image forming device. The remaining amount of toner is then obtained by subtracting the estimated value of the toner consumption from the amount of toner contained in an unused process cartridge 102A (initial toner amount). The initial toner amount is pre-stored in the storage unit, or can be read from a storage medium attached to the process cartridge 102A.

[0100] The pixel count method is an example of a method for detecting the amount of toner remaining inside the cartridge without using detection light, and other methods may be used. For example, the control unit 200 of the apparatus main body 100A may obtain the amount of toner remaining based on the initial toner amount of the process cartridge 102A and an estimated value of the amount of toner consumed based on the cumulative number of images formed since the process cartridge 102A was installed.

[0101] The process cartridge 102A includes a developing unit 15 including a toner storage section 105. The process cartridge 102A basically has the same configuration as the process cartridge 102 of the first embodiment (FIG. 2(a)), except that the process cartridge 102A does not include a light guide 410 and a light guide cover 420. Moreover, the process cartridge 102A does not include a portion that comes into contact with a positioning guide 455 (FIGS. 4(a) and 4(b)) of the detection device 400 when the process cartridge 102A is attached to the apparatus main body 100A.

[0102] When the process cartridge 102A is inserted into the apparatus main body 100A, the process cartridge 102A is mounted at a predetermined mounting position without a part of the process cartridge 102A coming into contact with the positioning guide 455 of the detection device 400. Therefore, the sensor unit 400A remains at the non-detection position before and after the process cartridge 102A is mounted. Also, the shutter 456 remains at the blocking position before and after the process cartridge 102A is mounted. In other words, the detection unit is located at the first position and the blocking member is located at the third position both when the cartridge is not mounted in the image forming apparatus main body and when the cartridge is mounted in the image forming apparatus main body.

[0103] In this modification, even when the process cartridge 102A is attached to the apparatus main body 100A, the light emitting element 451a and the light receiving element 451b are kept shielded by the shutter 456. This makes it possible to prevent the light emitting element 451a and the light receiving element 451b from being unnecessarily exposed even though they are not required for detecting the remaining toner amount, and to reduce adhesion of toner and the like to the light emitting element 451a and the light receiving element 451b. In addition, it is possible to reduce the possibility that the detection light L irradiated from the light emitting element 451a, even though it is not required for detecting the remaining toner amount, is irradiated onto the photosensitive drum 101 as leakage light (stray light), causing image defects.

[0104] In this manner, the image forming apparatus of this modified example has an apparatus main body 100A having a configuration in which the shutter 456 opens when a process cartridge 102 having a configuration for detecting the amount of remaining toner by light transmission is attached, as in the first embodiment. Therefore, the apparatus main body 100A is compatible with a process cartridge 102 having a configuration for detecting the amount of remaining toner by light transmission.

[0105] Moreover, in the image forming apparatus of this modification, when the process cartridge 102A that does not have a configuration for detecting the amount of remaining toner by light transmission is installed, the light emitting element 451a and the light receiving element 451b are kept shielded by the shutter 456. Therefore, when the process cartridge 102A that does not have a configuration for detecting the amount of remaining toner by light transmission is installed, an image forming apparatus that can reduce adhesion of toner, etc. to the light emitting element 451a and the light receiving element 451b can be provided. Also, when the process cartridge 102A is installed, an image forming apparatus that can reduce the occurrence of image defects caused by leaking light can be provided.

[0106] (Other variations) In the first embodiment, the sensor unit 400A is positioned by the light guide cover 420 of the process cartridge 102 abutting against the positioning guide 455 of the apparatus main body 100A. However, the present invention is not limited to this, and the sensor unit 400A may be positioned with respect to the light guide 410 by a part of the process cartridge 102 abutting against a member that moves integrally with the sensor unit 400A or a member that moves in conjunction with the sensor unit 400A. For example, the sensor unit 400A may be positioned by a part of the light guide 410 abutting against the substrate holder 450 when the process cartridge 102 is attached.

[0107] Second Embodiment Next, an image forming apparatus according to a second embodiment will be described. In the second embodiment, a detection device 401 is used, the configuration of which is partially different from that of the detection device 400 of the first embodiment. In the following description, elements with the same reference symbols as those in the first embodiment have substantially the same configurations and functions as those described in the first embodiment unless otherwise specified, and the following description will focus on the parts that are different from the first embodiment.

[0108] Detection Device Fig. 8(a) is a perspective view of a detection device 401 according to the second embodiment. Fig. 8(b) is an exploded view of the detection device 401. Fig. 8(c) is a perspective view showing a shutter 460, a shutter biasing spring 461, and a frame 457 of the detection device 401. Fig. 8(d) is a perspective view showing the shutter 460 and a substrate holder 450 of the detection device 401. Note that in Fig. 8(a), the biasing spring 454, the positioning member 449 (Fig. 5), and the frame 457 (Fig. 4(b)) are omitted from illustration.

[0109] 8(a) and (b), the detection device 401 has a sensor substrate 451, a substrate holder 450, a positioning guide 455, a shutter 460, and a shutter biasing spring 461. The configuration of the detection device 401, except for the shutter 460, the shutter biasing spring 461, and the substrate holder 450, is basically the same as that of the detection device 400 of the first embodiment.

[0110] Hereinafter, sensor substrate 451, substrate holder 450, and positioning guide 455 are collectively referred to as "sensor unit 401A." Sensor unit 401A is movable between a non-detection position (first position, standby position) and a detection position (second position).

[0111] 8(a) and (b), the shutter 460 is disposed between the substrate holder 450 and the frame 457 in the Z direction. One end of a shutter biasing spring 461 (tension spring) is attached to the shutter 460. The other end of the shutter biasing spring 461 is attached to a guide portion 449d (FIG. 8(c)) of a positioning member 449 fixed to the frame 457. The shutter 460 is biased in the -X direction by a biasing force F2 of the shutter biasing spring 461.

[0112] The shutter 460 is an example of a shielding member (opening / closing member) that is movable relative to both the frame 457 and the sensor unit 401A. The shutter 460 is movable between a shielding position (third position) and an exposed position (fourth position, retracted position). The shielding position (third position) is the position of the shutter 460 when the process cartridge 102 is not attached to the apparatus main body 100A. The exposed position (fourth position) is the position of the shutter 460 when the process cartridge 102 is attached to the apparatus main body 100A.

[0113] The exposed position in this embodiment is a position moved in the -X direction from the shielded position. That is, the shutter 460 can move from the shielded position to the exposed position according to the biasing force F2 of the shutter biasing spring 461. Also, the shutter 460 can move from the exposed position to the shielded position by being moved in the +X direction against the biasing force F2. The shutter biasing spring 461 is an example of a biasing means (second biasing means) that biases the shutter 460 as a shielding member toward the exposed position (fourth position), and a spring member other than a tension spring or an elastomer may be used.

[0114] The shutter 460 has a guided portion 460b guided by the guide portion 449d. The guided portion 460b in this embodiment is fitted with the convex guide portion 449d and forms a groove shape extending in the X direction. By being guided by the guide portion 449d, the shutter 460 moves linearly (slides) along a movement direction M3 intersecting with the movement direction M1 (FIG. 9(b-3)) of the sensor unit 401A.

[0115] In this embodiment, the movement direction M3 of the shutter 460 is a direction along the X direction (the longitudinal direction of the process cartridge 102), but the shutter 460 may be configured to move along another movement direction. For example, the shutter 460 may be configured to move linearly in the Y direction (the mounting direction D of the process cartridge 102), or in a direction that obliquely intersects the X direction and the Y direction. In such a case, the guide portion 449d and the guided portion 460b are formed in an orientation and shape that matches the movement direction of the shutter 460. Also, the shutter biasing spring 461 is changed to an arrangement that matches the movement direction of the shutter 460.

[0116] As shown in FIG. 8(d), the substrate holder 450 has a protrusion 450a, and the shutter 460 has an abutment portion 460a that abuts against the protrusion 450a. The protrusion 450a protrudes toward the Z direction side of the substrate holder 450 at a protrusion height that interferes with the shutter 460 in the Z direction. That is, the position of the protrusion 450a in the Z direction overlaps with the position of the abutment portion 460a in the Z direction. The protrusion 450a functions as a restricting portion that restricts the shutter 460 from moving relative to the substrate holder 450 in the -X direction. In other words, the protrusion 450a is an example of a restricting portion that restricts the shielding member from moving from the third position toward the fourth position when the detection unit is located at the first position. Also, the protrusion 450a allows the shielding member to move from the third position toward the fourth position when the detection unit moves from the first position to the second position.

[0117] <Operation when installing cartridge> 9, the operation of the detection device 401 when the process cartridge 102 is mounted in the apparatus main body 100A will be described. Note that the positioning guide 455 of the detection device 401 is pressed by the light guide cover 420 of the process cartridge 102 and moves in the same manner as in the first embodiment (FIGS. 6(a-1) to (a-3)), so a description thereof will be omitted.

[0118] 9(a-1) to (a-3) are views of the detection openings 457a, 457b and detection elements (451a, 451b) of the detection device 401, and the first light guiding portion 410a and the second light guiding portion 410b of the light guide 410 of the process cartridge 102, as viewed from the Z direction. FIG. 9(b-1) to (b-4) are views of the shutter 460, the shutter biasing spring 461, and the substrate holder 450 of the detection device 401, as viewed from the Z direction. Each of the views in FIG. 9 shows only some of the components of the toner remaining amount detection mechanism in this embodiment, and the illustration of the other components is omitted.

[0119] 9(a-1)(b-1), in the state before the cartridge is mounted, the sensor unit 401A is positioned at the non-detection position by the biasing force F1 of the biasing spring 454. Furthermore, when the sensor unit 401A is located at the non-detection position, the protrusion 450a of the substrate holder 450 abuts against the abutted portion 460a of the shutter 460. Therefore, the shutter 460 is held at the blocking position against the biasing force F2 of the shutter biasing spring 461.

[0120] 9(a-1)(b-1), in a state before the cartridge is mounted, when viewed from the Z direction, at least a part of the opening areas of the detection openings 457a, 457b is covered by the shutter 460. Furthermore, in a state before the cartridge is mounted, when viewed from the Z direction, at least a part of the light-emitting element 451a or at least a part of the light-receiving element 451b is located inside the opening areas of the detection openings 457a, 457b and is covered by the shutter 460.

[0121] In this manner, before the cartridge is attached, the shutter 460 shields the detection elements (451a, 451b) so that the detection elements (451a, 451b) are not exposed through the detection openings 457a, 457b. This protects the detection elements (451a, 451b) from contamination such as toner and dust scattered from the process cartridge 102, for example, and suppresses a decrease in detection accuracy due to the adhesion of contamination.

[0122] 9(a-2), (a-3), (b-2), and (b-3), in the process of inserting the process cartridge 102 in the mounting direction D, the sensor unit 401A moves in the moving direction M1 by being pressed by the light guide cover 420. In other words, the position of the sensor unit 401A in the Y direction changes in conjunction with the insertion of the process cartridge 102.

[0123] In contrast, the shutter 460 is configured to move in the X direction relative to the positioning member 449 and the frame 457, and therefore the position of the shutter 460 in the Y direction does not change in conjunction with the insertion of the process cartridge 102. Therefore, as the process cartridge 102 is inserted, the relative positions of the substrate holder 450 and the shutter 460 in the Y direction change.

[0124] Then, by the time the process cartridge 102 reaches the mounting position, the protrusion 450a of the substrate holder 450 is released from the abutted portion 460a of the shutter 460 as shown in FIG. 9(b-3). As a result, the shutter 460 slides in the -X direction according to the biasing force F2 of the shutter biasing spring 461, and moves from the shielding position to the exposed position. In other words, in this embodiment, the moving direction of the detection unit relative to the opening member is different from the moving direction of the shielding member relative to the opening member. Also, the relative movement of the detection unit and the shielding member when the detection unit moves from the first position to the second position causes the restricting portion to be released from the shielding member. This realizes the movement of the shielding member.

[0125] 9(a-3) and (b-3), when viewed from the Z direction in a state after the cartridge is mounted, the light emitting element 451a and the light receiving element 451b are not covered by the shutter 460 and are exposed inside the detection openings 457a and 457b. In addition, in a state after the cartridge is mounted, the light emitting element 451a faces the first light guiding portion 410a of the light guide 410 through the detection opening 457a, and the light receiving element 451b faces the second light guiding portion 410b of the light guide 410 through the detection opening 457b. Therefore, the detection device 401 is in a state where it can detect the remaining amount of toner in the process cartridge 102 by using the detection light L emitted by the light emitting element 451a.

[0126] In the present embodiment as well, the light emitting element 451a and the light receiving element 451b of the sensor unit 401A are positioned based on the light guide cover 420. This makes it possible to further stabilize the amount of light received by the light receiving element 451b, thereby improving the accuracy of detecting the remaining amount of toner.

[0127] When the process cartridge 102 is removed from the apparatus main body 100A, the light guide cover 420 is detached from the positioning guide 455. Then, as shown in Fig. 9(b-4), the sensor unit 401A slides in the direction opposite to the moving direction M1 in accordance with the biasing force F1 of the biasing spring 454, and moves from the detection position to the non-detection position.

[0128] As the sensor unit 401A moves, the protrusion 450a of the substrate holder 450 slides against the edge 460c of the shutter 460. The pressing force F4 acting on the shutter 460 at the contact surface between the protrusion 450a and the edge 460c is perpendicular to the contact surface and includes an X-direction component. Due to the X-direction component of the pressing force F4, the shutter 460 moves in the X-direction while expanding the shutter biasing spring 461, and returns to the shielding position shown in FIG. 9(b-1). The edge 460c of the shutter 460 is an example of a second pressed portion. That is, the shielding member of this embodiment moves from the fourth position to the third position against the biasing force of the second biasing means by the detection unit pressing the second pressed portion when the detection unit moves from the second position to the first position by the biasing force of the biasing means. This realizes the movement of the shielding member linked to the detection unit. Incidentally, before the sensor unit 401A reaches the non-detection position, the protrusion 450a comes into contact with the contact portion 460a of the shutter 460 again.

[0129] In addition, for example, the inclination of edge 460c toward the -Y direction side may be made larger than that shown in the figure so that the X-direction component of pressing force F4 (the component in the direction in which shutter 460 moves from the exposed position to the covered position) becomes larger. In addition, since the frictional force acting from protrusion 450a to edge 460c of shutter 460 includes a -X-direction component, protrusion 450a may be made of a rotatable roller or made of a material with high sliding properties so that the frictional force does not prevent shutter 460 from moving to the covered position. Not limited to this, the moving direction of shutter 460 and the biasing direction of shutter biasing spring 461 may be made orthogonal to the direction of biasing force F1 of biasing spring 454, for example, so that shutter 460 moves more smoothly from the exposed position to the covered position.

[0130] Furthermore, the contact portion between sensor unit 401A and shutter 460 when shutter 460 is moved from the exposing position to the blocking position may be a portion other than protruding portion 450a and a portion other than edge 460c.

[0131] Advantages of this embodiment As described above, the device body 100A of this embodiment includes the sensor unit 401A that can move between the non-detection position and the detection position, and the shutter 460 that can move between the shielding position and the exposure position. When the sensor unit 401A is located at the non-detection position and the shutter 460 is located at the shielding position, at least a part of the light-emitting element 451a or at least a part of the light-receiving element 451b is located inside the detection openings 457a and 457b and is covered by the shutter 460 when viewed from the Z direction (FIG. 9(a-1)). Also, when the sensor unit 401A is located at the detection position and the shutter 460 is located at the exposure position, the light-emitting element 451a and the light-receiving element 451b are exposed inside the detection openings 457a and 457b when viewed from the Z direction (FIG. 9(a-3)).

[0132] That is, when the detection unit is located at the first position and the shielding member is located at the third position, at least a part of the light-emitting unit or at least a part of the light-receiving unit is located inside the opening while being shielded by the shielding member when viewed in the optical axis direction of the light-emitting unit, and when the detection unit is located at the second position and the shielding member is located at the fourth position, the light-emitting unit and the light-receiving unit are located inside the opening without being shielded by the shielding member when viewed in the optical axis direction.

[0133] According to the configuration of this embodiment, by moving both the sensor unit 401A and the shutter 460, it is possible to realize a state in which the light emitting element 451a and the light receiving element 451b are shielded and a state in which both elements are exposed. Therefore, it is possible to shorten the moving distance of the sensor unit 401A and the moving distance of the shutter 456, and it is possible to reduce the space required for the toner remaining amount detection mechanism. In addition, it is possible to reduce the size of the apparatus main body 100A.

[0134] In this embodiment, the shutter 460 is moved from the shielding position to the exposing position by the biasing force F2 of the shutter biasing spring 461, and the protrusion 450a is provided as a restricting portion that restricts the movement of the shutter 460. With this configuration, the retraction amount of the shutter 460 with respect to the detection openings 457a, 457b can be easily ensured, and the arrangement of the shutter 460 can be space-saving.

[0135] Third Embodiment Next, an image forming apparatus according to a third embodiment will be described. In the third embodiment, a detection device 402 is used, the configuration of which is partially different from that of the detection device 400 of the first embodiment. In the following description, elements with the same reference symbols as those in the first embodiment have substantially the same configurations and functions as those described in the first embodiment unless otherwise specified, and the following description will focus on the parts that are different from the first embodiment.

[0136] Detection Device Fig. 10(a) is a perspective view of a detection device 402 according to the third embodiment. Fig. 10(b) is a diagram showing a shutter 462, a shutter biasing spring 463, and a positioning guide 455 of the detection device 402. Note that in Fig. 10(a), the biasing spring 454, the positioning member 449 (Fig. 5), and the frame 457 (Fig. 4(b)) are omitted from illustration.

[0137] 10(a) and (b), the detection device 402 has a sensor substrate 451, a substrate holder 450, a positioning guide 455, a shutter 462, and a shutter biasing spring 463. The configuration of the detection device 402, except for the shutter 462, the shutter biasing spring 463, and the positioning guide 455, is basically the same as that of the detection device 400 of the first embodiment.

[0138] Hereinafter, sensor substrate 451, substrate holder 450, and positioning guide 455 are collectively referred to as "sensor unit 402A." Sensor unit 402A is movable between a non-detection position (first position, standby position) and a detection position (second position).

[0139] As shown in Fig. 10(a)(b), the shutter 462 has a protruding portion 462a and a guided portion 462b. The shutter 462 is disposed so that the protruding portion 462a protrudes inward (toward the -X direction) from the contact portion 455b of the positioning guide 455. The shutter 462 is movable (advanceable and retractable) in a moving direction M4 (Fig. 11(a-2)(b-2)) in which the protruding portion 462a protrudes from and retracts from the contact portion 455b of the positioning guide 455. The moving direction M4 is a direction intersecting with the moving direction M1 (Fig. 11(a-3)(b-3)) of the sensor unit 402A when the cartridge is mounted. The protruding portion 462a is an example of a third pressed portion that is pressed by a part of the process cartridge 102 when the process cartridge 102 is mounted.

[0140] The guided portion 462b fits into a guide portion 455f provided on the positioning guide 455. The guided portion 462b is guided by the guide portion 455f, whereby the shutter 462 is movably supported by the sensor unit 402A. In other words, the shielding member of this embodiment is supported by the detection unit, and is movable relative to the detection unit in a direction in which the third pressed portion protrudes and retreats from the pressed portion.

[0141] The shutter biasing spring 463 is attached inside the positioning guide 455. The shutter biasing spring 463 of this embodiment is a torsion coil spring having one end engaged with the positioning guide 455 and the other end engaged with the shutter 462. The shutter 462 is biased in the −X direction by the biasing force F3 of the shutter biasing spring 463.

[0142] The shutter 462 is an example of a shielding member (opening / closing member) that is movable relative to both the frame 457 and the sensor unit 402A. The shutter 462 is movable between a shielding position (third position) and an exposed position (fourth position, retracted position). The shielding position (third position) is the position of the shutter 462 when the process cartridge 102 is not attached to the apparatus main body 100A. The exposed position (fourth position) is the position of the shutter 462 when the process cartridge 102 is attached to the apparatus main body 100A.

[0143] The exposed position in this embodiment is a position moved in the X direction from the shielded position. That is, the shutter 462 can move from the exposed position to the shielded position by moving in the -X direction in accordance with the biasing force F3 of the shutter biasing spring 463. The shutter 462 can also move from the shielded position to the exposed position by being moved in the X direction against the biasing force F3. The shutter biasing spring 463 is an example of a biasing means (third biasing means) that biases the shutter 462 as a shielding member toward the exposed position, and a spring member other than a torsion coil spring or an elastomer may be used.

[0144] The shutter 462 is an example of a shielding member that can advance and retreat with respect to the positioning guide 455 and the sensor unit 402A, and the movement direction of the shutter 462 can be changed as appropriate. For example, the shutter 462 may be configured to advance and retreat with respect to the positioning guide 455 in a direction along the mounting direction D (Y direction) of the process cartridge 102. Also, for example, the shutter 462 may be configured to advance and retreat with respect to the positioning guide 455 by rotating and moving with respect to the sensor unit 402A.

[0145] <Operation when installing cartridge> Next, the operation of the detection device 402 when the process cartridge 102 is mounted in the apparatus main body 100A will be described with reference to each diagram in Fig. 11. Note that the positioning guide 455 of the detection device 402 is pressed by the light guide cover 420 of the process cartridge 102 to move, which is the same as in the first embodiment (Figs. 6(a-1) to (a-3)), and therefore will be omitted.

[0146] 11(a-1) to (a-3) are views of the positioning guide 455 and shutter 462 of the detection device 402, and the light guide cover 420 of the process cartridge 102, as viewed from the Z direction. FIG. 11(b-1) to (b-3) are views of the shutter 462, shutter biasing spring 463, substrate holder 450, and sensor substrate 451 of the detection device 402, as viewed from the Z direction. Each of the views in FIG. 11 shows only some of the components of the toner remaining amount detection mechanism in this embodiment, and the illustration of the other components is omitted.

[0147] 11(a-1)(b-1), in the state before the cartridge is mounted, the sensor unit 402A is positioned at the non-detection position by the biasing force F1 of the biasing spring 454. In addition, the shutter 462 is positioned at the blocking position where the protruding portion 462a protrudes in the -X direction relative to the abutting portion 455b of the positioning guide 455 by the biasing force F3 of the shutter biasing spring 463.

[0148] 11(a-1) and (b-1), when viewed from the Z direction in a state before the cartridge is mounted, at least a part of the opening area of ​​the detection openings 457a, 457b is covered by the shutter 462. In this embodiment, the entire areas of the detection openings 457a, 457b are covered by the shutter 462. Furthermore, when viewed from the Z direction in a state before the cartridge is mounted, at least a part of the light-emitting element 451a or at least a part of the light-receiving element 451b is located inside the opening area of ​​the detection openings 457a, 457b and is covered by the shutter 462.

[0149] In this manner, before the cartridge is attached, the shutter 462 shields the detection elements (451a, 451b) so that the detection elements (451a, 451b) are not exposed through the detection openings 457a, 457b. This protects the detection elements (451a, 451b) from contamination such as toner and dust scattered from the process cartridge 102, for example, and suppresses a decrease in detection accuracy due to the adhesion of contamination.

[0150] 11(a-2) and 11(b-2), in the process of inserting the process cartridge 102 in the mounting direction D, the abutment portion 420c of the light guide cover 420 abuts against the protrusion 462a of the shutter 462. Then, the shutter 462 is pressed by the light guide cover 420 and moves in the X direction (the direction in which the protrusion 462a is accommodated inside the positioning guide 455) against the biasing force of the shutter biasing spring 463 with respect to the positioning guide 455. Then, when the process cartridge 102 is further inserted, the shutter 462 retreats from the detection openings 457a and 457b.

[0151] 11(a-3) and (b-3), when viewed from the Z direction in a state after the cartridge is mounted, the light emitting element 451a and the light receiving element 451b are not covered by the shutter 460 and are exposed inside the detection openings 457a and 457b. In addition, in a state after the cartridge is mounted, the light emitting element 451a faces the first light guiding portion 410a of the light guide 410 through the detection opening 457a, and the light receiving element 451b faces the second light guiding portion 410b of the light guide 410 through the detection opening 457b. Therefore, the detection device 402 is in a state in which it can detect the remaining amount of toner in the process cartridge 102 by using the detection light L emitted by the light emitting element 451a.

[0152] In the present embodiment as well, the light emitting element 451a and the light receiving element 451b of the sensor unit 401A are positioned based on the light guide cover 420. This makes it possible to further stabilize the amount of light received by the light receiving element 451b, thereby improving the accuracy of detecting the remaining amount of toner.

[0153] When the process cartridge 102 is removed from the apparatus main body 100A, the light guide cover 420 is released from the protruding portion 462a of the shutter 462, and the shutter 462 moves to the shielding position according to the biasing force F3 of the shutter biasing spring 463. In parallel with this, the light guide cover 420 is released from the abutment portions 455a, 455b of the positioning guide 455, and the sensor unit 402A moves to the non-detection position according to the biasing force of the biasing spring 454.

[0154] In addition, in the present embodiment, the configuration in which the light guide cover 420 of the process cartridge 102 presses the shutter 462 has been exemplified, but the shutter 462 may be pressed by another component of the process cartridge 102. For example, the shutter 462 may be configured to move from the shielding position to the exposing position by being pressed by the light guide 410.

[0155] Advantages of this embodiment As described above, the device body 100A of this embodiment includes the sensor unit 402A that can move between the non-detection position and the detection position, and the shutter 462 that can move between the shielding position and the exposure position. When the sensor unit 402A is located at the non-detection position and the shutter 462 is located at the shielding position, at least a part of the light-emitting element 451a or at least a part of the light-receiving element 451b is located inside the detection openings 457a and 457b and is covered by the shutter 462 when viewed from the Z direction (FIG. 11(a-1)). Also, when the sensor unit 402A is located at the detection position and the shutter 462 is located at the exposure position, the light-emitting element 451a and the light-receiving element 451b are exposed inside the detection openings 457a and 457b when viewed from the Z direction (FIG. 11(a-3)).

[0156] That is, when the detection unit is located at the first position and the shielding member is located at the third position, at least a part of the light-emitting unit or at least a part of the light-receiving unit is located inside the opening while being shielded by the shielding member when viewed in the optical axis direction of the light-emitting unit, and when the detection unit is located at the second position and the shielding member is located at the fourth position, the light-emitting unit and the light-receiving unit are located inside the opening without being shielded by the shielding member when viewed in the optical axis direction.

[0157] According to the configuration of this embodiment, by moving both the sensor unit 402A and the shutter 462, it is possible to realize a state in which the light emitting element 451a and the light receiving element 451b are shielded and a state in which both elements are exposed. Therefore, it is possible to shorten the moving distance of the sensor unit 402A and the moving distance of the shutter 456, and it is possible to reduce the space required for the toner remaining amount detection mechanism. In addition, it is possible to reduce the size of the apparatus main body 100A.

[0158] In this embodiment, the shutter 462 is held in the covering position by the shutter biasing spring 463 (third biasing means). The shutter 462 moves from the covering position to the exposed position by pressing the protruding portion 462a (third pressed portion) of the shutter 462 itself. In this manner, the position of the shutter 462 in this embodiment is directly controlled by the biasing force of the shutter biasing spring 463 and the pressing force of the protruding portion 462a, and is not affected by the movement of the sensor unit 402A when the process cartridge 102 is attached.

[0159] Therefore, while keeping the movement amount of the sensor unit 402A small, it is possible to switch between a state in which the detection elements (451a, 451b) and the detection openings 457a, 457b are sufficiently shielded and a state in which they are sufficiently exposed. Specifically, by increasing the stroke of the shutter biasing spring 463, it is possible to increase the shielding area of ​​the detection openings 457a, 457b by the shutter 462 located at the shielding position. In addition, by setting the shape of the protrusion 462a so that the movement amount of the shutter 462 when pressed against the light guide cover 420 is increased, it is possible to increase the opening area of ​​the detection openings 457a, 457b when the shutter 462 is located at the exposed position.

[0160] Other Embodiments In the above-described embodiment, a configuration in which the process cartridges 102, 102A each having a photosensitive drum 101 are mounted on the main body 100A of the apparatus is exemplified. However, the "cartridge" is not limited to a process cartridge each having a photosensitive drum, and may be a developing cartridge each having a developing roller and a toner storage section. In this case, the developing cartridge is mounted and removed from the main body of the apparatus independently of, for example, another cartridge each having a photosensitive drum. The "cartridge" may also be a supply container (toner cartridge) that contains a developer for replenishing a developing unit having a developing roller. In this case, the supply container is mounted and removed from the main body of the apparatus independently of, for example, a process cartridge including a developing unit. In these examples, the remaining amount of toner (amount of developer) in the cartridge can be detected by applying the configuration of the light-transmitting toner remaining amount detection mechanism described in the embodiment.

[0161] Summary of the Disclosure The present disclosure includes at least the following configurations or methods.

[0162] (Configuration 1) an opening member having an opening; A biasing means; a detection unit having a light-emitting section that emits light, a light-receiving section that emits a detection signal according to the amount of light received from the light-emitting section, and a pressure-receiving section, the detection unit being provided movably with respect to the opening member between a first position and a second position, being positioned at the first position by the biasing force of the biasing means, and being moved from the first position to the second position against the biasing force of the biasing means by pressing the pressure-receiving section; a shielding member movable relative to both the opening member and the detection unit between a third position and a fourth position; Equipped with when the detection unit is located at the first position and the shielding member is located at the third position, when viewed in the optical axis direction of the light-emitting unit, at least a part of the light-emitting unit or at least a part of the light-receiving unit is located inside the opening and is shielded by the shielding member, When the detection unit is located at the second position and the shielding member is located at the fourth position, when viewed in the optical axis direction, the light emitting unit and the light receiving unit are located inside the opening and are not shielded by the shielding member. 1. An image forming apparatus body comprising:

[0163] (Configuration 2) The detection unit has an engagement portion, the shielding member has an engaged portion engaged with the engaging portion such that the shielding member moves from the third position to the fourth position in conjunction with the movement of the detection unit from the first position to the second position, 2. The image forming apparatus body according to claim 1,

[0164] (Configuration 3) The shielding member is rotatable relative to the opening member, When the detection unit is located at the first position and the shielding member is located at the third position, a distance from a rotation center of the shielding member to the light-emitting portion and a distance from the rotation center to the light-receiving portion are longer than a distance from the rotation center to the engagement portion. 3. The image forming apparatus body according to claim 2.

[0165] (Configuration 4) the detection unit includes a sensor board on which the light-emitting portion and the light-receiving portion are provided, a board holder that holds the sensor board, a guide member on which the pressed portion is provided, and a connecting portion that connects the guide member and the board holder such that the sensor board, the board holder, and the guide member move integrally; The engagement portion is the connecting portion. 3. The image forming apparatus body according to claim 2.

[0166] (Configuration 5) In the optical axis direction, the sensor substrate and the substrate holder are disposed on a first side with respect to the opening member, and the guide member is disposed on a second side with respect to the opening member opposite to the first side, the shielding member is disposed on the first side of the aperture member in the optical axis direction and between the aperture member and the sensor substrate; 5. The image forming apparatus body according to configuration 4.

[0167] (Configuration 6) Further, a second biasing means is provided to bias the shielding member toward the fourth position, the detection unit has a restriction portion that restricts the shielding member from moving from the third position toward the fourth position when the detection unit is located at the first position, and that allows the shielding member to move from the third position toward the fourth position when the detection unit moves from the first position to the second position. 2. The image forming apparatus main body according to claim 1,

[0168] (Configuration 7) a moving direction of the detection unit relative to the opening member and a moving direction of the shielding member relative to the opening member are different, and the restricting portion is separated from the shielding member by a relative movement of the detection unit and the shielding member when the detection unit moves from the first position to the second position. 7. The image forming apparatus body according to configuration 6.

[0169] (Configuration 8) the shielding member has a second pressed portion, and when the detection unit moves from the second position to the first position by the biasing force of the biasing means, the detection unit presses the second pressed portion, thereby moving from the fourth position to the third position against the biasing force of the second biasing means. 7. The image forming apparatus body according to configuration 6.

[0170] (Configuration 9) Further, a third biasing means is provided to bias the shielding member toward the third position, the shielding member has a third pressed portion, and when the detection unit is pressed against the pressed portion, the shielding member moves from the third position to the fourth position against the biasing force of the third biasing means by pressing the third pressed portion. 2. The image forming apparatus main body according to claim 1,

[0171] (Configuration 10) the shielding member is supported by the detection unit, and the third pressed portion is movable relative to the detection unit in a direction in which the third pressed portion protrudes from and retracts from the pressed portion. 10. The image forming apparatus body according to configuration 9.

[0172] (Configuration 11) a positioning member for positioning the detection unit at the first position, the pressed portion includes a first force receiving portion that receives a pressing force in a first direction intersecting with the optical axis direction, and a second force receiving portion that receives a pressing force in a second direction intersecting with both the optical axis direction and the first direction, the positioning member includes a first abutment portion against which the detection unit abuts in a direction opposite to the first direction, and a second abutment portion against which the detection unit abuts in a direction opposite to the second direction, When the first force receiving portion and the second force receiving portion are not receiving a pressing force, the detection unit is positioned at the first position in a state where the detection unit is abutted against the first abutment portion and the second abutment portion by the biasing force of the biasing means. 11. The image forming apparatus main body according to any one of configurations 1 to 10.

[0173] (Configuration 12) the detection unit includes a sensor board on which the light-emitting portion and the light-receiving portion are provided, a board holder that holds the sensor board, and a guide member on which the pressed portion is provided, In the optical axis direction, the sensor substrate and the substrate holder are disposed on a first side with respect to the opening member, and the guide member is disposed on a second side with respect to the opening member opposite to the first side, the shielding member is disposed on the first side of the aperture member in the optical axis direction and between the aperture member and the sensor substrate; 11. The image forming apparatus body according to any one of configurations 1 to 3 and 6 to 10.

[0174] (Configuration 13) the opening includes a first hole and a second hole; when the detection unit is located at the first position and the shielding member is located at the third position, when viewed in the optical axis direction, a portion of the light-emitting unit is located inside the first hole and shielded by the shielding member, a remaining portion of the light-emitting unit is located outside the first hole and shielded by the opening member, a portion of the light-receiving unit is located inside the second hole and shielded by the shielding member, and a remaining portion of the light-receiving unit is located outside the second hole and shielded by the opening member. 11. The image forming apparatus main body according to any one of configurations 1 to 10.

[0175] (Configuration 14) a first cartridge is attachable to and detachable from the image forming apparatus main body, the first cartridge including a container for containing a developer, a first light guiding portion for guiding the light from the light emitting portion to an internal space of the container, and a second light guiding portion for guiding the light that has passed through the internal space of the container to the light receiving portion; When the first cartridge is not mounted in the image forming apparatus main body, the detection unit is located at the first position and the shielding member is located at the third position, When the first cartridge is attached to the image forming apparatus main body, the detection unit is located at the second position and the shielding member is located at the fourth position. 11. The image forming apparatus main body according to any one of configurations 1 to 10.

[0176] (Configuration 15) the first cartridge has a cover member that fits with the first light guiding portion and the second light guiding portion, the detection unit is moved from the first position to the second position by being pressed by the cover member when the first cartridge is attached to the image forming apparatus main body; 15. The image forming apparatus body according to configuration 14.

[0177] (Configuration 16) the image forming apparatus main body is capable of mounting and dismounting either the first cartridge or a second cartridge that does not have a light guide member that guides the light from the light emitting unit, When the second cartridge is attached to the image forming apparatus main body, the detection unit is located at the first position and the shielding member is located at the third position, the image forming apparatus main body further includes a control unit capable of acquiring an amount of developer contained in the second cartridge without using the detection unit when the second cartridge is attached to the image forming apparatus main body; 15. The image forming apparatus body according to configuration 14.

[0178] (Configuration 17) the control means acquires the amount of developer contained in the second cartridge based on information on the amount of developer contained in the second cartridge when the second cartridge is unused, the amount of developer consumed per pixel, and an integrated value of the number of pixels forming an image. 17. The image forming apparatus body according to claim 16,

[0179] (Configuration 18) An image forming apparatus main body, a cartridge that is mountable to and detachable from the main body of the image forming apparatus and has a container for housing a developer; An image forming apparatus comprising: The image forming apparatus main body includes: an opening member having an opening; A biasing means; a detection unit having a light-emitting section that emits light, a light-receiving section that emits a detection signal according to the amount of light received from the light-emitting section, and a pressure-receiving section, the detection unit being provided movably with respect to the opening member between a first position and a second position, being positioned at the first position by the biasing force of the biasing means, and being moved from the first position to the second position against the biasing force of the biasing means by pressing the pressure-receiving section; a shielding member movable relative to both the opening member and the detection unit between a third position and a fourth position; Equipped with the cartridge has a light guiding member including a first light guiding portion that guides the light from the light emitting portion to an internal space of the storage portion and a second light guiding portion that guides the light that has passed through the internal space of the storage portion to the light receiving portion; When the cartridge is not mounted in the image forming apparatus main body, the detection unit is located at the first position and the shielding member is located at the third position, When the cartridge is attached to the image forming apparatus main body, the detection unit is located at the second position and the shielding member is located at the fourth position, when the detection unit is located at the first position and the shielding member is located at the third position, when viewed in the optical axis direction of the light-emitting unit, at least a part of the light-emitting unit or at least a part of the light-receiving unit is located inside the opening and is shielded by the shielding member, when the detection unit is located at the second position and the shielding member is located at the fourth position, the light emitting portion and the first light guiding portion face each other through the opening, and the light receiving portion and the second light guiding portion face each other through the opening; 1. An image forming apparatus comprising:

[0180] (Configuration 19) the cartridge has a cover member that fits with the first light guiding portion and the second light guiding portion, the detection unit moves from the first position to the second position by being pressed by the cover member when the cartridge is attached to the image forming apparatus main body; 19. The image forming apparatus according to configuration 18,

[0181] (Configuration 20) An image forming apparatus main body, a cartridge that is mountable to and detachable from the main body of the image forming apparatus and has a container for housing a developer; An image forming apparatus comprising: The image forming apparatus main body includes: an opening member having an opening; A biasing means; a detection unit having a light-emitting section that emits light, a light-receiving section that emits a detection signal according to the amount of light received from the light-emitting section, and a pressure-receiving section, the detection unit being provided movably with respect to the opening member between a first position and a second position, being positioned at the first position by the biasing force of the biasing means, and being moved from the first position to the second position against the biasing force of the biasing means by pressing the pressure-receiving section; a shielding member movable relative to both the opening member and the detection unit between a third position and a fourth position; having the detection unit is located at the first position and the shielding member is located at the third position in both a state in which the cartridge is not mounted in the image forming apparatus main body and a state in which the cartridge is mounted in the image forming apparatus main body, when the detection unit is located at the first position and the shielding member is located at the third position, when viewed in the optical axis direction of the light-emitting unit, at least a part of the light-emitting unit or at least a part of the light-receiving unit is located inside the opening and is shielded by the shielding member, When the detection unit is located at the second position and the shielding member is located at the fourth position, when viewed in the optical axis direction, the light emitting unit and the light receiving unit are located inside the opening and are not shielded by the shielding member, the image forming apparatus main body further includes a control unit capable of acquiring an amount of the developer in the container without using the detection unit; 1. An image forming apparatus comprising:

[0182] (Configuration 21) the control means acquires the amount of developer contained in the cartridge based on information on the amount of developer contained in the cartridge in an unused state, the amount of developer consumed per pixel, and an integrated value of the number of pixels on which an image is formed. 21. The image forming apparatus according to configuration 20.

[0183] (Configuration 22) The detection unit has an engagement portion, the shielding member has an engaged portion engaged with the engaging portion such that the shielding member moves from the third position to the fourth position in conjunction with the movement of the detection unit from the first position to the second position, 22. The image forming apparatus according to any one of configurations 18 to 21.

[0184] (Configuration 23) The shielding member is rotatable relative to the opening member, When the detection unit is located at the first position and the shielding member is located at the third position, a distance from a rotation center of the shielding member to the light-emitting portion and a distance from the rotation center to the light-receiving portion are longer than a distance from the rotation center to the engagement portion. 23. The image forming apparatus according to configuration 22.

[0185] (Configuration 24) the detection unit includes a sensor board on which the light-emitting portion and the light-receiving portion are provided, a board holder that holds the sensor board, a guide member on which the pressed portion is provided, and a connecting portion that connects the guide member and the board holder such that the sensor board, the board holder, and the guide member move integrally; The engagement portion is the connecting portion. 24. The image forming apparatus according to claim 22 or 23.

[0186] (Configuration 25) In the optical axis direction, the sensor substrate and the substrate holder are disposed on a first side with respect to the opening member, and the guide member is disposed on a second side with respect to the opening member opposite to the first side, the shielding member is disposed on the first side of the aperture member in the optical axis direction and between the aperture member and the sensor substrate; 25. The image forming apparatus according to configuration 24.

[0187] (Configuration 26) Further, a second biasing means is provided to bias the shielding member toward the fourth position, the detection unit has a restriction portion that restricts the shielding member from moving from the third position toward the fourth position when the detection unit is located at the first position, and that allows the shielding member to move from the third position toward the fourth position when the detection unit moves from the first position to the second position. 22. The image forming apparatus according to any one of configurations 18 to 21.

[0188] (Configuration 27) a moving direction of the detection unit relative to the opening member and a moving direction of the shielding member relative to the opening member are different, and the restricting portion is separated from the shielding member by a relative movement of the detection unit and the shielding member when the detection unit moves from the first position to the second position. 27. The image forming apparatus according to claim 26,

[0189] (Configuration 28) the shielding member has a second pressed portion, and when the detection unit moves from the second position to the first position by the biasing force of the biasing means, the detection unit presses the second pressed portion, thereby moving from the fourth position to the third position against the biasing force of the second biasing means. 28. The image forming apparatus according to claim 26 or 27,

[0190] (Configuration 29) Further, a third biasing means is provided to bias the shielding member toward the third position, the shielding member has a third pressed portion, and when the detection unit is pressed against the pressed portion, the shielding member moves from the third position to the fourth position against the biasing force of the third biasing means by pressing the third pressed portion. 22. The image forming apparatus according to any one of configurations 18 to 21.

[0191] (Configuration 30) the shielding member is supported by the detection unit, and the third pressed portion is movable relative to the detection unit in a direction in which the third pressed portion protrudes from and retracts from the pressed portion. 30. The image forming apparatus according to claim 29, [Explanation of symbols]

[0192] 100...Image forming apparatus / 100A...Image forming apparatus main body (apparatus main body) / 102...Cartridge, first cartridge (process cartridge) / 102A...Cartridge, second cartridge (process cartridge) / 400A, 401A, 402A...Detection unit (sensor unit) / 451a...Light emitting portion (light emitting element) / 451b...Light receiving portion (light receiving element) / 454...Pressing means (pressing spring) / 455a, 455b...Pressed portion (contact portion) / 456, 460, 462...Shielding member (shutter) / 457...Opening member (frame) / 457a, 457b...Opening (detection opening)

Claims

1. an opening member having an opening; A biasing means; a detection unit having a light-emitting portion that emits light, a light-receiving portion that emits a detection signal corresponding to a received amount of light emitted by the light-emitting portion, and a pressed portion, the detection unit being provided movably with respect to the opening member between a first position and a second position, being positioned at the first position by the biasing force of the biasing means, and being moved from the first position to the second position against the biasing force of the biasing means by pressing the pressed portion; a shielding member movable relative to both the opening member and the detection unit between a third position and a fourth position; Equipped with when the detection unit is located at the first position and the shielding member is located at the third position, when viewed in the optical axis direction of the light-emitting unit, at least a part of the light-emitting unit or at least a part of the light-receiving unit is located inside the opening and is shielded by the shielding member, When the detection unit is located at the second position and the shielding member is located at the fourth position, when viewed in the optical axis direction, the light emitting unit and the light receiving unit are located inside the opening and are not shielded by the shielding member.

1. An image forming apparatus body comprising:

2. The detection unit has an engagement portion, the shielding member has an engaged portion engaged with the engaging portion such that the shielding member moves from the third position to the fourth position in conjunction with the movement of the detection unit from the first position to the second position; 2. The image forming apparatus according to claim 1, wherein the image forming apparatus main body includes a first fixing member and a second fixing member.

3. The shielding member is rotatable relative to the opening member, When the detection unit is located at the first position and the shielding member is located at the third position, a distance from a rotation center of the shielding member to the light-emitting portion and a distance from the rotation center to the light-receiving portion are longer than a distance from the rotation center to the engagement portion.

3. The image forming apparatus according to claim 2, wherein the image forming apparatus main body includes a first fixing member and a second fixing member.

4. the detection unit includes a sensor board on which the light-emitting portion and the light-receiving portion are provided, a board holder that holds the sensor board, a guide member on which the pressed portion is provided, and a connecting portion that connects the guide member and the board holder such that the sensor board, the board holder, and the guide member move integrally; The engagement portion is the connecting portion.

3. The image forming apparatus according to claim 2, wherein the image forming apparatus main body includes a first fixing member and a second fixing member.

5. In the optical axis direction, the sensor substrate and the substrate holder are disposed on a first side with respect to the opening member, and the guide member is disposed on a second side with respect to the opening member opposite to the first side, the shielding member is disposed on the first side of the aperture member in the optical axis direction and between the aperture member and the sensor substrate; 5. The image forming apparatus body according to claim 4.

6. Further, a second biasing means is provided to bias the shielding member toward the fourth position, the detection unit has a restriction portion that restricts the shielding member from moving from the third position toward the fourth position when the detection unit is located at the first position, and that allows the shielding member to move from the third position toward the fourth position when the detection unit moves from the first position to the second position.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus main body includes a first fixing member and a second fixing member.

7. a moving direction of the detection unit with respect to the opening member and a moving direction of the shielding member with respect to the opening member are different, and the restricting portion is separated from the shielding member by a relative movement between the detection unit and the shielding member when the detection unit moves from the first position to the second position.

7. The image forming apparatus body according to claim 6,

8. the shielding member has a second pressed portion, and when the detection unit moves from the second position to the first position by the biasing force of the biasing means, the detection unit presses the second pressed portion, thereby moving from the fourth position to the third position against the biasing force of the second biasing means.

7. The image forming apparatus body according to claim 6,

9. a third biasing means for biasing the shielding member toward the third position; the shielding member has a third pressed portion, and when the detection unit is pressed against the pressed portion, the shielding member moves from the third position to the fourth position against the biasing force of the third biasing means by pressing the third pressed portion.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus main body includes a first fixing member and a second fixing member.

10. the shielding member is supported by the detection unit, and the third pressed portion is movable relative to the detection unit in a direction in which the third pressed portion protrudes from and retracts from the pressed portion.

10. The image forming apparatus body according to claim 9,

11. a positioning member for positioning the detection unit at the first position; the pressed portion includes a first force receiving portion that receives a pressing force in a first direction intersecting with the optical axis direction, and a second force receiving portion that receives a pressing force in a second direction intersecting with both the optical axis direction and the first direction, the positioning member includes a first abutment portion against which the detection unit abuts in a direction opposite to the first direction, and a second abutment portion against which the detection unit abuts in a direction opposite to the second direction, When the first force receiving portion and the second force receiving portion are not receiving a pressing force, the detection unit is positioned at the first position in a state where the detection unit is abutted against the first abutment portion and the second abutment portion by the biasing force of the biasing means.

11. The image forming apparatus main body according to claim 1,

12. the detection unit includes a sensor board on which the light-emitting portion and the light-receiving portion are provided, a board holder that holds the sensor board, and a guide member on which the pressed portion is provided, In the optical axis direction, the sensor substrate and the substrate holder are disposed on a first side with respect to the opening member, and the guide member is disposed on a second side with respect to the opening member opposite to the first side, the shielding member is disposed on the first side of the aperture member in the optical axis direction and between the aperture member and the sensor substrate; 11. The image forming apparatus main body according to claim 1, wherein the image forming apparatus main body is a unit that is connected to the image forming unit.

13. the opening includes a first hole and a second hole; when the detection unit is located at the first position and the shielding member is located at the third position, when viewed in the optical axis direction, a portion of the light-emitting portion is located inside the first hole and shielded by the shielding member, a remaining portion of the light-emitting portion is located outside the first hole and shielded by the opening member, a portion of the light-receiving portion is located inside the second hole and shielded by the shielding member, and a remaining portion of the light-receiving portion is located outside the second hole and shielded by the opening member.

11. The image forming apparatus main body according to claim 1,

14. a first cartridge is mountable and detachable to the image forming apparatus main body, the first cartridge including a container for containing a developer, a first light guiding portion for guiding the light from the light emitting portion to an internal space of the container, and a second light guiding portion for guiding the light that has passed through the internal space of the container to the light receiving portion; When the first cartridge is not mounted in the image forming apparatus main body, the detection unit is located at the first position and the shielding member is located at the third position, When the first cartridge is attached to the image forming apparatus main body, the detection unit is located at the second position and the shielding member is located at the fourth position.

11. The image forming apparatus main body according to claim 1,

15. the first cartridge has a cover member that fits with the first light guiding portion and the second light guiding portion, the detection unit is pressed by the cover member when the first cartridge is attached to the image forming apparatus main body, and moves from the first position to the second position.

15. The image forming apparatus body according to claim 14.

16. the image forming apparatus main body is capable of mounting and dismounting either the first cartridge or a second cartridge that does not have a light guide member that guides the light from the light emitting unit, When the second cartridge is attached to the image forming apparatus main body, the detection unit is located at the first position and the shielding member is located at the third position, the image forming apparatus main body further includes a control unit capable of acquiring an amount of developer contained in the second cartridge without using the detection unit when the second cartridge is attached to the image forming apparatus main body; 15. The image forming apparatus body according to claim 14.

17. the control means acquires the amount of developer contained in the second cartridge based on information on the amount of developer contained in the second cartridge when the second cartridge is unused, the amount of developer consumed per pixel, and an integrated value of the number of pixels forming an image.

17. The image forming apparatus body according to claim 16.

18. An image forming apparatus main body, a cartridge that is mountable to and detachable from the main body of the image forming apparatus and has a container for housing a developer; An image forming apparatus comprising: The image forming apparatus main body includes: an opening member having an opening; A biasing means; a detection unit having a light-emitting portion that emits light, a light-receiving portion that emits a detection signal corresponding to a received amount of light emitted by the light-emitting portion, and a pressed portion, the detection unit being provided movably with respect to the opening member between a first position and a second position, being positioned at the first position by the biasing force of the biasing means, and being moved from the first position to the second position against the biasing force of the biasing means by pressing the pressed portion; a shielding member movable relative to both the opening member and the detection unit between a third position and a fourth position; Equipped with the cartridge has a light guiding member including a first light guiding portion that guides the light from the light emitting portion to an internal space of the storage portion and a second light guiding portion that guides the light that has passed through the internal space of the storage portion to the light receiving portion; When the cartridge is not mounted in the image forming apparatus main body, the detection unit is located at the first position and the shielding member is located at the third position, When the cartridge is attached to the image forming apparatus main body, the detection unit is located at the second position and the shielding member is located at the fourth position, when the detection unit is located at the first position and the shielding member is located at the third position, when viewed in the optical axis direction of the light-emitting unit, at least a part of the light-emitting unit or at least a part of the light-receiving unit is located inside the opening and is shielded by the shielding member, when the detection unit is located at the second position and the shielding member is located at the fourth position, the light emitting portion and the first light guiding portion face each other through the opening, and the light receiving portion and the second light guiding portion face each other through the opening; 1. An image forming apparatus comprising:

19. the cartridge has a cover member that fits with the first light guiding portion and the second light guiding portion, the detection unit is moved from the first position to the second position by being pressed by the cover member when the cartridge is mounted in the image forming apparatus main body; 20. The image forming apparatus according to claim 18,

20. An image forming apparatus main body, a cartridge that is mountable to and detachable from the main body of the image forming apparatus and has a container for housing a developer; An image forming apparatus comprising: The image forming apparatus main body includes: an opening member having an opening; A biasing means; a detection unit having a light-emitting portion that emits light, a light-receiving portion that emits a detection signal corresponding to a received amount of light emitted by the light-emitting portion, and a pressed portion, the detection unit being provided movably with respect to the opening member between a first position and a second position, being positioned at the first position by the biasing force of the biasing means, and being moved from the first position to the second position against the biasing force of the biasing means by pressing the pressed portion; a shielding member movable relative to both the opening member and the detection unit between a third position and a fourth position; having in both a state in which the cartridge is not mounted in the image forming apparatus main body and a state in which the cartridge is mounted in the image forming apparatus main body, the detection unit is located at the first position and the shielding member is located at the third position, when the detection unit is located at the first position and the shielding member is located at the third position, when viewed in the optical axis direction of the light-emitting unit, at least a part of the light-emitting unit or at least a part of the light-receiving unit is located inside the opening and is shielded by the shielding member, when the detection unit is located at the second position and the shielding member is located at the fourth position, when viewed in the optical axis direction, the light emitting unit and the light receiving unit are located inside the opening and are not shielded by the shielding member, the image forming apparatus main body further includes a control unit capable of acquiring an amount of the developer in the container without using the detection unit; 1. An image forming apparatus comprising:

21. the control means acquires the amount of developer contained in the cartridge based on information on the amount of developer contained in the cartridge in an unused state, the amount of developer consumed per pixel, and an integrated value of the number of pixels forming an image.

21. The image forming apparatus according to claim 20.

22. The detection unit has an engagement portion, the shielding member has an engaged portion engaged with the engaging portion such that the shielding member moves from the third position to the fourth position in conjunction with the movement of the detection unit from the first position to the second position; 22. The image forming apparatus according to claim 18,

23. The shielding member is rotatable relative to the opening member, When the detection unit is located at the first position and the shielding member is located at the third position, a distance from a rotation center of the shielding member to the light-emitting portion and a distance from the rotation center to the light-receiving portion are longer than a distance from the rotation center to the engagement portion.

23. The image forming apparatus according to claim 22.

24. the detection unit includes a sensor board on which the light-emitting portion and the light-receiving portion are provided, a board holder that holds the sensor board, a guide member on which the pressed portion is provided, and a connecting portion that connects the guide member and the board holder such that the sensor board, the board holder, and the guide member move integrally; The engagement portion is the connecting portion.

23. The image forming apparatus according to claim 22.

25. In the optical axis direction, the sensor substrate and the substrate holder are disposed on a first side with respect to the opening member, and the guide member is disposed on a second side with respect to the opening member opposite to the first side, the shielding member is disposed on the first side of the aperture member in the optical axis direction and between the aperture member and the sensor substrate; 25. The image forming apparatus according to claim 24.

26. Further, a second biasing means is provided to bias the shielding member toward the fourth position, the detection unit has a restriction portion that restricts the shielding member from moving from the third position toward the fourth position when the detection unit is located at the first position, and that allows the shielding member to move from the third position toward the fourth position when the detection unit moves from the first position to the second position.

22. The image forming apparatus according to claim 18,

27. a moving direction of the detection unit with respect to the opening member and a moving direction of the shielding member with respect to the opening member are different, and the restricting portion is separated from the shielding member by a relative movement between the detection unit and the shielding member when the detection unit moves from the first position to the second position.

27. The image forming apparatus according to claim 26.

28. the shielding member has a second pressed portion, and when the detection unit moves from the second position to the first position by the biasing force of the biasing means, the detection unit presses the second pressed portion, thereby moving from the fourth position to the third position against the biasing force of the second biasing means.

27. The image forming apparatus according to claim 26.

29. a third biasing means for biasing the shielding member toward the third position; the shielding member has a third pressed portion, and when the detection unit is pressed against the pressed portion, the shielding member moves from the third position to the fourth position against the biasing force of the third biasing means by pressing the third pressed portion.

22. The image forming apparatus according to claim 18,

30. the shielding member is supported by the detection unit, and the third pressed portion is movable relative to the detection unit in a direction in which the third pressed portion protrudes from and retracts from the pressed portion.

30. The image forming apparatus according to claim 29.

Images