Image forming apparatus

Abstract

To provide an image forming apparatus that has improved the accuracy of detection with a light emitting section and a light receiving section.SOLUTION: An image forming apparatus forms a toner image formed on an image carrier on a sheet, and the image forming apparatus comprises: an apparatus main body; and a process unit that has a frame body that constitutes a storage section storing developer, a developer carrier that supplies developer to an electrostatic latent image formed on the image carrier to develop the electrostatic latent image, and a substrate that is attached to the frame body, the process unit attached to the apparatus main body. The substrate has a light emitting section that emits light, and a light receiving section that receives the light emitted from the light emitting section and having passed through the inside of the storage section.SELECTED DRAWING: Figure 15

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus for forming an image on a recording material. [Background technology]

[0002] In general, an electrophotographic image forming apparatus forms an image by transferring a toner image formed on the surface of a photosensitive drum to a transfer material as a transfer medium. A known method of replenishing toner is, for example, a process cartridge method in which the photosensitive drum and a developing container are integrated as a process cartridge, and when the toner runs out, the process cartridge is replaced with a new one.

[0003] Conventionally, a toner remaining amount detection device has been proposed that detects the amount of toner remaining in a toner cartridge that contains toner (see Patent Document 1). This toner remaining amount detection device has transparent windows on each of the two opposing walls of the toner cartridge, and an optical path between the light-emitting unit and the light-receiving unit is set so that light passes through these transparent windows. The optical path that traverses inside the toner cartridge is either transmitted or blocked depending on the amount of toner remaining, and the amount of toner remaining in the toner cartridge can be detected by measuring the time it takes for the optical path to pass through. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-186822 Summary of the Invention [Problem to be solved by the invention]

[0005] In a process cartridge type image forming apparatus, there is a small gap between the image forming apparatus main body and the process cartridge so that the process cartridge can be attached and detached from the image forming apparatus main body. Therefore, when the light emitting unit and the light receiving unit described in Patent Document 1 are provided in the image forming apparatus main body, there is a risk of misalignment between the process cartridge and the light emitting unit and the light receiving unit, which may reduce the accuracy of detecting the remaining toner amount.

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an image forming apparatus with improved detection accuracy by a light emitting section and a light receiving section. [Means for solving the problem]

[0007] The present invention is an image forming apparatus comprising: an apparatus main body; and a process unit mounted on the apparatus main body, the process unit having a frame body constituting a storage section for storing developer, a developer carrier supported by the frame body and carrying the developer stored in the storage section, and a substrate, the substrate having a light emitting section that emits light and a light receiving section that receives light emitted from the light emitting section and passed through the inside of the storage section, the process unit having a holder that holds the substrate, and a positioning section provided on the frame body that determines the position of the holder relative to the frame body, the positioning section being configured to determine the position of the substrate relative to the frame body. Effect of the Invention

[0008] According to the present invention, it is possible to provide an image forming apparatus in which the detection accuracy by the light emitting section and the light receiving section is improved. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1A is a cross-sectional view showing an image forming apparatus according to a first embodiment, and FIG. [Diagram 2] FIG. 2A is a cross-sectional view showing an image forming apparatus, and FIG. 2B is a perspective view showing the image forming apparatus with a top cover open. [Diagram 3]FIG. 2 is a cross-sectional view showing the image forming apparatus with a process unit removed. [Figure 4] (a) is an oblique view showing an image forming apparatus with the pressure plate of the reading device closed, (b) is an oblique view showing an image forming apparatus with the pressure plate open, and (c) is an oblique view showing an image forming apparatus with the reading device open. [Diagram 5] FIG. 4A is a perspective view showing a developing container and a toner pack, and FIG. [Figure 6] 5(b) is a cross-sectional view taken along line 6A-6A in FIG. 5(b), and (b) is a cross-sectional view taken along line 6B-6B in FIG. 5(b). [Figure 7] FIG. [Figure 8] FIG. 4A is a front view showing a toner pack, FIG. 4B is a front view showing a first modified example of the toner pack, and FIG. 4C is a front view showing a second modified example of the toner pack. [Figure 9] 9A is a cross-sectional view showing the toner remaining amount sensor, and FIG. 9B is a cross-sectional view taken along line 9B-9B of FIG. [Figure 10] FIG. 4 is a circuit diagram showing a remaining toner sensor. [Figure 11] FIG. 4A is a cross-sectional view showing a developing container when the amount of remaining toner is small, and FIG. 4B is a cross-sectional view showing a developing container when the amount of remaining toner is large. [Figure 12] FIG. 2 is a block diagram showing a control system of the image forming apparatus. [Figure 13] 1A is a perspective view of the toner remaining panel 400 showing the NearOut level, FIG. 1B is a perspective view of the toner remaining panel 400 showing the Low level, FIG. 1C is a perspective view of the toner remaining panel 400 showing the Mid level, and FIG. 1D is a perspective view of the toner remaining panel 400 showing the Fll level. [Figure 14] FIG. [Figure 15] 1A is a perspective view showing the state in which the substrate and the substrate holding member are attached to the developing container lid, FIG. 1B is a perspective view showing the substrate and the substrate holding member, and FIG. 1C is another perspective view showing the substrate and the substrate holding member. [Figure 16] (a) is a cross-sectional view of the developing device, and (b) is a cross-sectional view taken along 16B-16B of (a). [Figure 17] FIG. 4A is a cross-sectional view showing a developing container when the amount of remaining toner is small, and FIG. 4B is a cross-sectional view showing a developing container when the amount of remaining toner is large. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[0011] <First embodiment> 1(a) is a schematic diagram showing the configuration of an image forming apparatus 1 according to a first embodiment. The image forming apparatus 1 is a monochrome printer that forms an image on a recording material based on image information input from an external device. The recording material includes various sheet materials of different materials, such as paper such as plain paper and thick paper, plastic films such as sheets for overhead projectors, sheets of special shapes such as envelopes and index paper, and cloth.

[0012] [Overall configuration] 1(a) and 1(b), the image forming apparatus 1 has a printer main body 100 as the apparatus main body, a reading device 200 supported by the printer main body 100 so as to be openable and closable, and an operation unit 300 attached to the exterior surface of the printer main body 100. The printer main body 100 has an image forming unit 10 that forms a toner image on a recording material, a feeding unit 60 that feeds the recording material to the image forming unit 10, a fixing unit 70 that fixes the toner image formed by the image forming unit 10 to the recording material, and a pair of discharge rollers 80.

[0013] The image forming section 10 includes a scanner unit 11, an electrophotographic process unit 20, and a transfer roller 12 that transfers a toner image, which is a developer image formed on a photosensitive drum 21 of the process unit 20, to a recording material. As shown in FIGS. 6(a) and 6(b), the process unit 20 includes a photosensitive drum 21 and a developing device 30 including a charging roller 22, a pre-exposure device 23, and a developing roller 31 arranged around the photosensitive drum 21. The process unit 20 is detachably attached to the printer body 100 (see FIG. 3). The process unit 20 may be screwed to the printer body 100, and may be removed mainly by a serviceman rather than a user. On the other hand, the process unit 20 does not include structural members of the printer body 100, such as a housing frame of the printer body 100.

[0014] The photosensitive drum 21 is a cylindrically shaped photosensitive member. The photosensitive drum 21 of this embodiment has a photosensitive layer formed of a negatively charged organic photosensitive member on a drum-shaped base body formed of aluminum. The photosensitive drum 21 as an image carrier is rotated by a motor in a predetermined direction (clockwise direction in the figure) at a predetermined process speed.

[0015] The charging roller 22 comes into contact with the photosensitive drum 21 with a predetermined pressure to form a charging portion. A desired charging voltage is applied by a charging high-voltage power supply to uniformly charge the surface of the photosensitive drum 21 to a predetermined potential. In this embodiment, the photosensitive drum 21 is negatively charged by the charging roller 22. The pre-exposure device 23 neutralizes the surface potential of the photosensitive drum 21 before it enters the charging portion in order to generate a stable discharge in the charging portion.

[0016] The scanner unit 11 as an exposure means scans and exposes the surface of the photosensitive drum 21 by irradiating the photosensitive drum 21 with laser light corresponding to image information input from an external device or the reading device 200 using a polygon mirror. This exposure forms an electrostatic latent image corresponding to the image information on the surface of the photosensitive drum 21. Note that the scanner unit 11 is not limited to a laser scanner device, and may be, for example, an LED exposure device having an LED array in which a plurality of LEDs are arranged along the longitudinal direction of the photosensitive drum 21.

[0017] The developing device 30 includes a developing roller 31 as a developer carrier that carries a developer, a developing container 32 as a frame of the developing device 30, and a supply roller 33 capable of supplying the developer to the developing roller 31. The developing roller 31 and the supply roller 33 are rotatably supported by the developing container 32. The developing roller 31 is disposed at an opening of the developing container 32 so as to face the photosensitive drum 21. The supply roller 33 rotatably contacts the developing roller 31, and the toner contained in the developing container 32 as the developer is applied to the surface of the developing roller 31 by the supply roller 33. Note that the supply roller 33 is not necessarily required as long as the developing roller 31 is configured to be sufficiently supplied with toner.

[0018] The developing device 30 of this embodiment uses a contact development method as a development method. That is, the toner layer carried by the developing roller 31 comes into contact with the photosensitive drum 21 in a development section (development area) where the photosensitive drum 21 and the developing roller 31 face each other. A development voltage is applied to the developing roller 31 by a development high-voltage power supply. Under the development voltage, the toner carried by the developing roller 31 is transferred from the developing roller 31 to the drum surface according to the potential distribution on the surface of the photosensitive drum 21, so that the electrostatic latent image is developed into a toner image. Note that this embodiment employs a reversal development method. That is, the toner image is formed by adhering to the surface area of ​​the photosensitive drum 21, which is charged in the charging process and then exposed in the exposure process, where the charge amount is attenuated.

[0019] In this embodiment, a toner having a particle size of 6 μm and a normal charging polarity of negative polarity is used. As an example of the toner in this embodiment, a polymerized toner produced by a polymerization method is used. The toner in this embodiment does not contain a magnetic component, and is a so-called non-magnetic one-component developer in which the toner is carried on the developing roller 31 mainly by intermolecular forces and electrostatic forces (image forces). However, a one-component developer containing a magnetic component may be used. In addition to toner particles, the one-component developer may contain additives (e.g., wax or silica particles) for adjusting the fluidity and charging performance of the toner. A two-component developer composed of a non-magnetic toner and a magnetic carrier may be used as the developer. When a magnetic developer is used, a cylindrical developing sleeve with a magnet arranged inside is used as the developer carrier.

[0020] An agitating member 34 is provided inside the developing container 32. The agitating member 34 is driven to rotate by a motor M1 (see FIG. 12) to agitate the toner in the developing container 32 and transport the toner toward the developing roller 31 and the supply roller 33. The agitating member 34 also circulates the toner that has not been used for development and has been scraped off from the developing roller 31 within the developing container, thereby making the toner in the developing container uniform. The agitating member 34 is not limited to a rotating type. For example, an agitating member in an oscillating type may be adopted. In addition to the agitating member 34, another agitating member may be provided.

[0021] In addition, a developing blade 35 that regulates the amount of toner carried by the developing roller 31 is disposed at the opening of the developing container 32 in which the developing roller 31 is disposed. The toner supplied to the surface of the developing roller 31 passes through the portion facing the developing blade 35 as the developing roller 31 rotates, whereby the toner is uniformly formed into a thin layer and is negatively charged by frictional charging.

[0022] 1(a) and 1(b), the feeding section 60 has a front door 61 supported by the printer body 100 so as to be openable and closable, a tray section 62, a middle plate 63, a tray spring 64, and a pickup roller 65. The tray section 62 constitutes the bottom surface of a recording material storage space that appears when the front door 61 is opened, and the middle plate 63 is supported by the tray section 62 so as to be movable up and down. The tray spring 64 biases the middle plate 63 upward, and presses the recording material P loaded on the middle plate 63 against the pickup roller 65. The front door 61 closes the recording material storage space when closed relative to the printer body 100, and supports the recording material P together with the tray section 62 and the middle plate 63 when opened relative to the printer body 100.

[0023] The fixing unit 70 is a thermal fixing type that fixes an image by heating and melting the toner on the recording material. The fixing unit 70 includes a fixing film 71, a fixing heater such as a ceramic heater that heats the fixing film 71, a thermistor that measures the temperature of the fixing heater, and a pressure roller 72 that is in pressure contact with the fixing film 71.

[0024] Next, an image forming operation of the image forming apparatus 1 will be described. When an image formation command is input to the image forming apparatus 1, an image forming process is started by the image forming section 10 based on image information input from an external computer or a reading device 200 connected to the image forming apparatus 1. The scanner unit 11 irradiates a laser beam toward the photosensitive drum 21 based on the input image information. At this time, the photosensitive drum 21 is charged in advance by the charging roller 22, and an electrostatic latent image is formed on the photosensitive drum 21 by irradiating it with the laser beam. Thereafter, the electrostatic latent image is developed by the developing roller 31, and a toner image is formed on the photosensitive drum 21.

[0025] In parallel with the above-mentioned image forming process, the pickup roller 65 of the feeding section 60 feeds out the recording material P supported by the front door 61, the tray section 62, and the middle plate 63. The recording material P is fed by the pickup roller 65 to the pair of registration rollers 15, and the skew of the recording material P is corrected by hitting the nip of the pair of registration rollers 15. The pair of registration rollers 15 is then driven in accordance with the transfer timing of the toner image, and conveys the recording material P toward the transfer nip formed by the transfer roller 12 and the photosensitive drum 21.

[0026] A transfer voltage is applied to the transfer roller 12 as a transfer means from a transfer high voltage power supply, and the toner image carried on the photosensitive drum 21 is transferred to the recording material P being transported by a pair of registration rollers 15. The recording material P with the transferred toner image is transported to a fixing section 70, where the toner image is heated and pressurized as it passes through a nip between a fixing film 71 and a pressure roller 72 of the fixing section 70. This causes the toner particles to melt and then adhere, thereby fixing the toner image to the recording material P. The recording material P that has passed through the fixing section 70 is discharged to the outside of the image forming apparatus 1 (outside the machine) by a pair of discharge rollers 80, and is loaded onto a discharge tray 81 formed on the top of the printer main body 100.

[0027] The discharge tray 81 is inclined upward toward the downstream in the discharge direction of the recording material, and the recording material discharged to the discharge tray 81 slides down the discharge tray 81 so that the trailing edge of the recording material is aligned by a regulating surface 84 .

[0028] 4(a) and 4(b), the reading device 200 has a reading unit 201 with a built-in reading section (not shown), and a pressure plate 202 supported so as to be openable and closable by the reading unit 201. On the upper surface of the reading unit 201, there is provided a document table glass 203 that transmits light emitted from the reading section and on which a document is placed.

[0029] When a user wants to read an image of an original document by the reading device 200, the user places the original document on the glass platen 203 with the pressure platen 202 open. Then, the user closes the pressure platen 202 to prevent the original document on the glass platen 203 from being displaced, and outputs a reading command to the image forming device 1 by operating the operation unit 300, for example. When the reading operation is started, the reading unit in the reading unit 201 moves back and forth in the sub-scanning direction, that is, in the left and right directions with the operation unit 300 of the image forming device 1 facing the front. The reading unit emits light to the original document from the light-emitting unit, receives the light reflected by the original document with the light-receiving unit, and reads the image of the original document by photoelectric conversion. In the following, the front-rear direction, left-right direction, and up-down direction are defined based on the state in which the operation unit 300 faces the front.

[0030] As shown in Fig. 2(b) and Fig. 3, a first opening 101 that opens upward is formed in the upper part of the printer body 100, and the first opening 101 is covered by a top cover 82. The top cover 82 as a loading tray is supported so as to be openable and closable with respect to the printer body 100 around a rotation shaft 82c extending in the left-right direction, and a discharge tray 81 as a loading surface is formed on the upper surface. The top cover 82 is opened from the front side to the back side when the reading device 200 is in an open state with respect to the printer body 100. The reading device 200 and the top cover 82 may be configured to be held in an open state and a closed state by a holding mechanism such as a hinge mechanism.

[0031] For example, if the recording material is jammed due to a paper jam or the like in the conveying path CP through which the recording material fed by the pickup roller 65 passes, the user opens the top cover 82 together with the reading device 200. Then, the user accesses the process unit 20 from a first opening 101 exposed when the top cover 82 is opened, and pulls out the process unit 20 along the process guide 102. The process guide 102 guides the process unit 20 by sliding over a protrusion 21a (see FIG. 5(a)) provided at an end of the photosensitive drum 21 of the process unit 20 in the axial direction.

[0032] Then, by drawing the process unit 20 outward from the first opening 101, a space is created where the user can reach into the conveying path CP. The user can reach into the printer body 100 from the first opening 101 and access the jammed recording material on the conveying path CP, thereby disposing of the jammed recording material.

[0033] In the present embodiment, as shown in FIG. 1(b) and FIG. 4(c), an opening / closing member 83 is provided on the top cover 82 so as to be openable / closable. A second opening 82a is formed in the discharge tray 81 of the top cover 82 as an opening that opens upward. The opening / closing member 83 is configured to be movable between a closed position in which the supply port 32a is covered so that the toner pack 40 cannot be attached to the developing container 32, and an open position in which the supply port 32a is exposed so that the toner pack 40 can be attached to the developing container 32. In the closed position, the opening / closing member 83 functions as a part of the discharge tray 81. The opening / closing member 83 and the second opening 82a are formed on the left side of the discharge tray 81. The opening / closing member 83 is supported on the top cover 82 so as to be openable / closable around a rotation shaft 83a extending in the front-rear direction, and is opened to the left by hooking a finger in a groove portion 82b provided in the top cover 82. Therefore, a user can access the supply port 32a simply by opening the opening / closing member 83. The opening / closing member 83 is formed in a substantially L-shape to fit the shape of the top cover .

[0034] The second opening 82a of the discharge tray 81 is opened so that the supply port 32a for supplying toner formed at the top of the developing container 32 is exposed, and the user can access the supply port 32a without opening the top cover 82 by opening the opening / closing member 83. In this embodiment, a method (direct supply method) is adopted in which the user supplies toner from the toner pack 40 (see FIGS. 1(a) and (b)) filled with toner for supplying to the developing device 30 while the developing device 30 is still attached to the image forming device 1. Therefore, when the remaining amount of toner in the process unit 20 becomes low, it is not necessary to remove the process unit 20 from the printer body 100 and replace it with a new process unit, so usability can be improved. In addition, toner can be supplied to the developing container 32 at a lower cost than replacing the entire process unit 20. In addition, the direct supply method does not require replacing various rollers, gears, etc., compared to replacing only the developing device 30 of the process unit 20, so costs can be reduced. In addition, the image forming device 1 and the toner pack 40 constitute an image forming system.

[0035] [Recovery of residual toner after transfer] In this embodiment, a cleaner-less configuration is adopted in which the transfer residual toner remaining on the photosensitive drum 21 without being transferred to the recording material P is collected in the developing device 30 and reused. The transfer residual toner is removed in the following process. The transfer residual toner is a mixture of toner that is positively charged and toner that is negatively charged but does not have a sufficient charge. The photosensitive drum 21 after transfer is discharged by the pre-exposure device 23, and the transfer residual toner is charged negatively again by causing uniform discharge by the charging roller 22. The transfer residual toner that has been charged negatively again in the charging section reaches the developing section as the photosensitive drum 21 rotates. Then, the surface area of ​​the photosensitive drum 21 that has passed the charging section is exposed by the scanner unit 11 with the transfer residual toner still attached to the surface, and an electrostatic latent image is written thereon.

[0036] Here, the behavior of the transfer residual toner that has reached the development section will be described separately for the exposed and non-exposed sections of the photosensitive drum 21. The transfer residual toner adhering to the non-exposed section of the photosensitive drum 21 is transferred to the development roller 31 in the development section due to the potential difference between the potential (dark section potential) of the non-exposed section of the photosensitive drum 21 and the development voltage, and is then collected in the development container 32. This is because the normal charging polarity of the toner is negative, and the development voltage applied to the development roller 31 is positive relative to the potential of the non-exposed section. The toner collected in the development container 32 is agitated and dispersed with the toner in the development container by the agitation member 34, and is carried by the development roller 31 for reuse in the development process.

[0037] On the other hand, the transfer residual toner adhering to the exposed portion of the photosensitive drum 21 remains on the drum surface without being transferred from the photosensitive drum 21 to the developing roller 31 in the developing portion. This is because the normal charging polarity of the toner is negative, and the developing voltage applied to the developing roller 31 has a potential that is more negative than the potential of the exposed portion (light portion potential). The transfer residual toner remaining on the drum surface is carried by the photosensitive drum 21 together with other toner transferred from the developing roller 31 to the exposed portion, and moves to the transfer portion, where it is transferred to the recording material P.

[0038] In this manner, the present embodiment has a cleanerless configuration in which the transfer residual toner is collected in the developing device 30 and reused, but a conventionally known configuration may be used in which the transfer residual toner is collected using a cleaning blade that contacts the photosensitive drum 21. In that case, the transfer residual toner collected by the cleaning blade is collected in a collection container that is installed separately from the developing device 30. However, by adopting a cleanerless configuration, no installation space is required for a collection container that collects the transfer residual toner, etc., making it possible to further reduce the size of the image forming apparatus 1, and also reducing printing costs by reusing the transfer residual toner.

[0039] [Developer container and toner pack configuration] Next, the configurations of the developing container 32 and the toner pack 40 as a supply container will be described. Fig. 5(a) is a perspective view showing the developing container 32 and the toner pack 40, and Fig. 5(b) is a front view showing the developing container 32 and the toner pack 40. Fig. 6(a) is a cross-sectional view taken along line 6A-6A in Fig. 5(b), and Fig. 6(b) is a cross-sectional view taken along line 6B-6B in Fig. 5(b).

[0040] 5(a) to 6(b), the developing container 32 has a transport chamber 36 that houses an agitating member 34, and the transport chamber 36 as a container that houses toner extends over the entire length in the longitudinal direction LD (left-right direction) of the developing container 32. The transport chamber 36 is integral with a frame that rotatably supports the developing roller 31 and the supply roller 33, and houses toner (developer) to be carried by the developing roller 31. The developing container 32 has a first protruding portion 37 that protrudes upward from one end of the transport chamber 36 in the longitudinal direction and communicates with the transport chamber 36, and a second protruding portion 38 that protrudes upward from the other end of the transport chamber 36 in the longitudinal direction. That is, the first protrusion 37 is provided at one end of the developing container 32 in the rotational axis direction of the developing roller 31, i.e., the longitudinal direction LD, and protrudes toward the discharge tray 81 in a direction intersecting the rotational axis direction beyond the center of the developing container 32.

[0041] The second protruding portion 38 is provided at the other end of the developer container 32 in the direction of the rotation axis of the developer roller 31, and protrudes toward the discharge tray 81 in the intersecting direction beyond the center of the developer container 32. In the present embodiment, the first protruding portion 37 is formed on the left side of the developer container 32, and the second protruding portion 38 is formed on the right side of the developer container 32. An attachment portion 57 to which the toner pack 40 can be attached is provided at the upper end (tip) of the first protruding portion 37, and a supply port 32a is formed in the attachment portion 57 for supplying developer from the toner pack 40 to the transport chamber 36. The toner pack 40 can be attached to the attachment portion 57 in a state where it is exposed to the outside of the device.

[0042] The first protruding portion 37 and the second protruding portion 38 extend obliquely from the transport chamber 36 toward the front and upward of the device. That is, the first protruding portion 37 and the second protruding portion 38 protrude toward the downstream and upward in the discharge direction of the discharge roller pair 80. Therefore, the supply port 32a formed in the first protruding portion 37 is disposed on the front side of the image forming apparatus 1, and the operation of supplying toner to the developing container 32 can be easily performed.

[0043] In particular, in this embodiment, the reading device 200 that can be opened and closed centering on the rear side of the device is disposed above the opening / closing member 83, so that disposing the supply port 32a at the front of the device can effectively utilize the space between the supply port 32a and the reading device 200. Therefore, the workability when replenishing toner through the supply port 32a can be improved.

[0044] An upper portion of the first protruding portion 37 and an upper portion of the second protruding portion 38 are connected by a grip portion 39 serving as a connecting portion. Between the grip portion 39 and the transport chamber 36, a laser passing space SP is formed as a gap through which a laser L (see FIG. 1(a)) emitted from the scanner unit 11 (see FIG. 1(a)) toward the photosensitive drum 21 can pass.

[0045] The grip portion 39 has a knob portion 39a that a user can grip by hooking his / her fingers, and the knob portion 39a is formed to protrude upward from the top surface of the grip portion 39. The first protrusion 37 is hollow inside, and a supply port 32a is formed on the top surface. The supply port 32a is configured to be connectable to the toner pack 40.

[0046] By providing the first protrusion 37, the tip of which is formed with the supply port 32a, on one side in the longitudinal direction of the developing container 32, a laser passing space SP through which the laser L emitted from the scanner unit 11 can pass can be secured, and the image forming apparatus 1 can be made compact. In addition, by providing the second protrusion 38 on the other side in the longitudinal direction of the developing container 32 and forming a handle portion 39 connecting the first protrusion 37 and the second protrusion 38, usability can be improved when removing the process unit 20 from the printer body 100. Note that the second protrusion 38 may be formed in a hollow shape like the first protrusion 37, or may be in a solid shape.

[0047] As shown in Figs. 5(a) to 6(b), the toner pack 40 is configured to be detachably attached to the mounting portion 57 of the first protrusion 37. The toner pack 40 has a shutter member 41 provided at the opening and capable of opening and closing, and a plurality of (three in this embodiment) protrusions 42 formed corresponding to a plurality of (three in this embodiment) grooves 32b formed in the mounting portion 57. When replenishing toner to the developing container 32, the user aligns the toner pack 40 so that the protrusions 42 pass through the grooves 32b of the mounting portion 57, and connects the toner pack 40 to the mounting portion 57. When the toner pack 40 is rotated 180 degrees in this state, the shutter member 41 of the toner pack 40 abuts against an abutment portion (not shown) of the mounting portion 57, rotating the toner pack 40 relative to the main body of the toner pack 40 and opening the shutter member 41. As a result, the toner contained in the toner pack 40 leaks out from the toner pack 40, and the leaked toner enters the hollow first protrusion 37 through the supply port 32a. The shutter member 41 may be provided on the supply port 32a side.

[0048] The first protrusion 37 has a slope 37a at a position facing the opening of the supply port 32a, and the slope 37a is inclined downward toward the transport chamber 36. Therefore, the toner supplied from the supply port 32a is guided to the transport chamber 36 by the slope 37a. As shown in Figures 6(a) and 6(b), the agitator 34 has an agitator shaft 34a extending in the longitudinal direction and a blade portion 34b extending radially outward from the agitator shaft 34a. The blade portion 34b is a flexible sheet.

[0049] The toner supplied from the supply port 32a arranged on the upstream side in the conveying direction of the stirring member 34 is sent toward the developing roller 31 and the supply roller 33 as the stirring member 34 rotates. The conveying direction of the stirring member 34 is parallel to the longitudinal direction LD of the developing container 32 (see FIG. 5(b)). The supply port 32a and the first protrusion 37 are arranged at one end of the developing container 32 in the longitudinal direction LD, and the toner is distributed over the entire length of the developing container 32 by repeatedly rotating the stirring member 34. In this embodiment, the stirring member 34 is composed of the stirring shaft 34a and the blade portion 34b, but a spiral-shaped stirring shaft may be used as a configuration for distributing the toner over the entire length of the developing container 32.

[0050] In this embodiment, the toner pack 40 is made of a plastic bag that is easily deformed as shown in FIG. 7 and FIG. 8(a), but is not limited thereto. For example, the toner pack may be made of a bottle container 40B having a substantially conical shape as shown in FIG. 8(b), or may be made of a paper container 40C made of paper as shown in FIG. 8(c). In any case, the toner pack may be made of any material and any shape. In addition, the method of discharging the toner from the toner pack is preferably a method in which the user squeezes the toner pack 40 or the paper container 40C with his / her fingers, and in the case of the bottle container 40B, it is preferable that the user shakes the container by tapping it to cause the toner to leak out. In addition, a discharge mechanism may be provided in the bottle container 40B to discharge the toner from the bottle container 40B. Furthermore, the discharge mechanism may be configured to engage with the printer main body 100 and receive a driving force from the printer main body 100.

[0051] Also, in any of the toner packs, the shutter member 41 may be omitted, or a sliding type shutter member may be applied instead of the rotating type shutter member 41. Also, the shutter member 41 may be configured to be destroyed when the toner pack is attached to the supply port 32a or when the toner pack is rotated in the attached state, or may have a removable lid structure such as a seal.

[0052] [How to detect remaining toner] Next, a method for detecting the remaining toner amount in the developing container 32 will be described with reference to Fig. 9(a) to Fig. 11(b). Fig. 9(a) is a cross-sectional view showing the remaining toner amount sensor 51, and Fig. 9(b) is a schematic cross-sectional view of the 9B-9B cross section of Fig. 9(a) seen in the direction from the developing roller 31 side toward the developing container 32. Fig. 10 is a circuit diagram showing an example of the circuit configuration of the remaining toner amount sensor 51.

[0053] As shown in Figs. 9(a) and 9(b), the developing container 32 of this embodiment is provided with a toner remaining amount sensor 51 for detecting remaining amount information corresponding to the remaining amount of toner in the transport chamber 36. The toner remaining amount sensor 51 is disposed on the side surface of the developing container 32 opposite to the developing roller 31, i.e., the side surface 36a, and has a light emitting portion 51a and a light receiving portion 51b. The light emitting portion 51a and the light receiving portion 51b are disposed side by side in the longitudinal direction LD of the process unit 20. Light emitted from the light emitting portion 51a passes through the inside of the transport chamber 36 and is received by the light receiving portion 51b. That is, the light emitting portion 51a and the light receiving portion 51b form an optical path Q1 inside the transport chamber 36. The optical path Q1 extends in the longitudinal direction LD. In addition, the light-emitting unit 51a and the light-receiving unit 51b may have their light-emitting element and light-receiving element respectively arranged inside the transport chamber 36, or the light-emitting element and light-receiving element may be arranged outside the transport chamber 36, and light may be guided inside and outside the transport chamber 36 by a light-guiding unit.

[0054] Furthermore, the light emitting portion 51a and the light receiving portion 51b are provided in the central portion of the transport chamber 36 in the longitudinal direction LD. More specifically, the light emitting portion 51a and the light receiving portion 51b are arranged in an area AR1 corresponding to the laser passing space SP in the longitudinal direction LD. The light emitting portion 51a is arranged between the supply port 32a and the central portion 31a of the developing roller 31 in the longitudinal direction LD. The dashed line in FIG. 9(b) indicates a position corresponding to the central portion 31a of the developing roller 31. The central portion 31a of the developing roller 31 is arranged between the light emitting portion 51a and the light receiving portion 51b in the longitudinal direction LD. In this way, by providing the light emitting portion 51a and the light receiving portion 51b in the central portion of the transport chamber 36, the remaining amount of toner in the transport chamber 36 can be detected well. That is, developer (toner) may be unevenly distributed at the ends of the transport chamber 36 in the longitudinal direction LD, but since developer is less unevenly distributed in the central part of the transport chamber 36, the actual amount of remaining toner can be detected.

[0055] In FIG. 10, an LED is used for the light-emitting section 51a, and a phototransistor that is turned on by the light from the LED is used for the light-receiving section 51b, but this is not limited thereto. For example, a halogen lamp or a fluorescent lamp may be applied to the light-emitting section 51a, and a photodiode or an avalanche photodiode may be applied to the light-receiving section 51b. A switch (not shown) is provided between the light-emitting section 51a and the power supply voltage Vcc, and by turning on the switch, a voltage from the power supply voltage Vcc is applied to the light-emitting section 51a, and the light-emitting section 51a is brought into a conductive state. On the other hand, a switch (not shown) is also provided between the light-receiving section 51b and the power supply voltage Vcc, and by turning on the switch, the light-receiving section 51b is brought into a conductive state by a current corresponding to the detected amount of light.

[0056] A power supply voltage Vcc and a current limiting resistor R1 are connected to the light emitting unit 51a, and the light emitting unit 51a emits light with a current determined by the current limiting resistor R1. The light emitted from the light emitting unit 51a passes through an optical path Q1 as shown in FIG. 9(b) and is received by the light receiving unit 51b. A power supply voltage Vcc is connected to the collector terminal of the light receiving unit 51b, and a detection resistor R2 is connected to the emitter terminal. The light receiving unit 51b, which is a phototransistor, receives the light emitted from the light emitting unit 51a and outputs a signal (current) according to the amount of light received. This signal is converted to a voltage V1 by the detection resistor R2 and input to an A / D conversion unit 95 of the control unit 90 (see FIG. 12). That is, the light receiving unit 51b changes its output value according to the amount of toner (developer) contained in the conveying chamber 36.

[0057] The control unit 90 (CPU 91) judges whether the light receiving unit 51b has received light from the light emitting unit 51a based on the input voltage level. The control unit 90 (CPU 91) calculates the amount of toner (amount of developer) in the developing container 32 based on the length of time that the light receiving unit 51b detects each light and the intensity of the received light when the toner in the developing container 32 is stirred for a certain time by the stirring member 34. That is, the ROM 93 stores in advance a table that can output the remaining toner amount from the light receiving time and light intensity when the toner is transported by the stirring member 34, and the control unit 90 predicts / calculates the remaining toner amount based on the input to the A / D conversion unit 95 and the table.

[0058] 9A, the optical path Q1 of the toner remaining amount sensor 51 is set to overlap with the rotation locus T of the agitating member 34 when viewed in the axial direction of the rotation shaft of the agitating member 34. In other words, the light emitted from the light-emitting portion 51a of the toner remaining amount sensor 51 passes through the inside of the conveying chamber 36 within the rotation locus of the agitating member 34 when viewed in the axial direction of the agitating member 34. The time during which the optical path Q1 is blocked by the toner conveyed by the agitating member 34 when the agitating member 34 makes one rotation, that is, the time during which the light-receiving portion 51b does not detect the light from the light-emitting portion 51a, varies depending on the amount of remaining toner. The intensity of light received by the light-receiving portion 51b also varies depending on the amount of remaining toner.

[0059] In other words, when the remaining toner amount is large, the light path Q1 is easily blocked by the toner, so the time that the light receiving element 51b receives light is shortened and the intensity of the light received by the light receiving element 51b is reduced. On the other hand, when the remaining toner amount is small, the time that the light receiving element 51b receives light is lengthened and the intensity of the light received by the light receiving element 51b is strong. Therefore, the control unit 90 can determine the remaining toner level as follows based on the light receiving time and light receiving intensity of the light receiving element 51b.

[0060] For example, as shown in Fig. 11(a), when there is a small amount of toner in the transport chamber 36 of the developing container 32, the time that the light receiving portion 51b receives light becomes longer and the intensity of the light received by the light receiving portion 51b becomes stronger, so it is determined that the remaining amount of toner is small. On the other hand, as shown in Fig. 11(b), when there is a large amount of toner in the transport chamber 36 of the developing container 32, the time that the light receiving portion 51b receives light becomes shorter and the intensity of the light received by the light receiving portion 51b becomes smaller, so it is determined that the remaining amount of toner is large.

[0061] The method for detecting / estimating the remaining toner amount is not limited to the optical toner remaining amount detection method described in Fig. 9, and various well-known methods for detecting / estimating the remaining toner amount can be adopted. For example, two or more metal plates or conductive resin sheets extending in the longitudinal direction of the developing roller may be arranged on the inner wall of the developing container 32, which is the frame, and the electrostatic capacitance between the two metal plates or conductive resin sheets may be measured to detect / estimate the remaining toner amount. Alternatively, a load cell may be provided to support the developing device 30 from below, and the CPU 51 may calculate the remaining toner amount by subtracting the weight of the developing device 30 when it is empty from the weight measured by the load cell.

[0062] [Image forming device control system] 12 is a block diagram showing a control system of the image forming apparatus 1. A control unit 90 as a control means of the image forming apparatus 1 has a CPU 91 as a calculation device, a RAM 92 used as a work area for the CPU 91, and a ROM 93 for storing various programs. The control unit 90 also has an I / O interface 94 as an input / output port connected to an external device, and an A / D conversion unit 95 for converting an analog signal into a digital signal.

[0063] The input side of the control unit 90 is connected to the toner remaining amount sensor 51, the mounting sensor 53, and the opening / closing sensor 54, and the mounting sensor 53 detects that the toner pack 40 is mounted in the supply port 32a of the developing container 32. For example, the mounting sensor 53 is provided in the supply port 32a and is composed of a pressure-sensitive switch that outputs a detection signal when pressed by the protrusion 42 of the toner pack 40. The opening / closing sensor 54 detects whether the opening / closing member 83 is opened relative to the top cover 82. The opening / closing sensor 54 is composed of, for example, a pressure-sensitive switch or a magnetic sensor.

[0064] The control unit 90 is also connected to an operation unit 300, the image forming unit 10, and a toner remaining amount panel 400 as a notification means capable of notifying information regarding the remaining amount of toner. The operation unit 300 has a display unit 301 capable of displaying various setting screens, physical keys, etc. The display unit 301 is, for example, a liquid crystal panel. The image forming unit 10 has a motor M1 as a drive source for driving the photosensitive drum 21, the developing roller 31, the supply roller 33, the stirring member 34, etc. The photosensitive drum 21, the developing roller 31, the supply roller 33, and the stirring member 34 may be configured to be driven by separate motors, respectively.

[0065] 1(b) and 13(a) to (d), the toner remaining amount panel 400 is provided on the right side of the front surface of the housing of the printer main body 100, i.e., on the opposite side to the operation unit 300 provided on the left side, and displays information related to the amount of toner remaining in the developing container 32. In this embodiment, the toner remaining amount panel 400 is a panel member made up of multiple scales (three in this embodiment) arranged vertically, and each scale corresponds to a low level, a mid level, and a full level.

[0066] That is, as shown in Fig. 13(a), when only the lower scale is flashing, the remaining amount of toner in the developing container 32 indicates the NearOut level. As shown in Fig. 13(b), when only the lower scale is lit, the remaining amount of toner in the developing container 32 indicates the Low level. As shown in Fig. 13(c), when the lower and center scales are lit and the upper scale is off, the remaining amount of toner in the developing container 32 indicates the Mid level. As shown in Fig. 13(d), when all three scales are lit, the remaining amount of toner in the developing container 32 indicates the Full level.

[0067] The NearOut level indicates the amount of remaining toner when the toner in the developing container 32 will soon run out and proper image formation will no longer be possible. The Low level indicates the amount of remaining toner that is more than the NearOut level and less than the Mid level. The Mid level indicates the amount of remaining toner that is more than the Low level and less than the Full level.

[0068] The toner remaining amount panel 400 is not limited to a liquid crystal panel, and may be composed of a light source such as an LED or an incandescent lamp and a diffusion lens. Alternatively, the toner remaining amount panel 400 may not be provided separately, and the display of the operation unit 300 may display the toner remaining amount using scales as described in the present embodiment. When the toner remaining amount in the developing container 32 reaches a low level, a replenishment notice may be displayed on the operation unit 300 to encourage toner replenishment. When toner runs out, a replenishment notice may be displayed on the operation unit 300 to encourage toner replenishment.

[0069] In the present embodiment, the configuration in which four states are displayed using three scales has been described, but the number of scales is not limited to this and may be set appropriately depending on the configuration of the image forming apparatus. The remaining toner amount may be continuously displayed using a percentage display or a gauge display. The remaining toner amount may be notified to the user by voice using a speaker.

[0070] 13(a) to 13(d), the toner remaining amount panel 400 has been described as a means for notifying the user of the remaining amount of toner, but the present invention is not limited to this. For example, the display in Fig. 13(b) may indicate that toner replenishment is necessary, the display in Fig. 13(c) may indicate that toner replenishment is unnecessary, and the display in Fig. 13(d) may indicate that toner replenishment has been performed sufficiently.

[0071] As described above, in this embodiment, the light emitting portion 51a and the light receiving portion 51b of the toner remaining amount sensor 51 are provided in the process unit 20 including the transport chamber 36 that contains the toner. Therefore, the relative position of the optical path Q1 in the transport chamber 36 is constant, and the amount of remaining toner can be stably detected regardless of the positional accuracy of the process unit 20 with respect to the printer body 100.

[0072] In addition, since the relative position of the optical path Q1 in the transport chamber 36 is constant, there is no need to design the toner remaining amount sensor 51 and the developing container 32 taking into consideration the positional deviation between the transport chamber 36 and the optical path Q1 in advance. Therefore, for example, there is no need to select an optical element by providing a margin for the light amount of the toner remaining amount sensor 51, and the design freedom of the toner remaining amount sensor 51 and the developing container 32 can be improved and costs can be reduced.

[0073] In addition, the light-emitting unit 51a and the light-receiving unit 51b in this embodiment are arranged side by side in the longitudinal direction LD of the process unit 20, and are arranged on the same side (the front side) of the transfer chamber 36 as viewed in the longitudinal direction LD. Therefore, the light-emitting unit 51a and the light-receiving unit 51b can be arranged compactly, and the power supply configuration that supplies power to the light-emitting unit 51a and the light-receiving unit 51b can also be arranged compactly. This allows the process unit 20 to be made smaller.

[0074] In this embodiment, a method (direct supply method) is adopted in which toner is directly supplied to the developing container 32 by the toner pack 40 from the supply port 32a, so that there is no need to remove the process unit 20 when supplying toner to the developing container 32. In addition, the supply port 32a of the developing container 32 is formed on the upper surface of the first protruding portion 37 that protrudes upward from one end in the longitudinal direction of the conveying chamber 36, and is therefore disposed close to the second opening 82a. Therefore, the user can easily perform the work of supplying toner to the developing container 32 through the supply port 32a. In addition, since there is no need to replace parts such as the developing roller 31 and the supply roller 33 when supplying toner to the developing container 32, costs can be reduced.

[0075] Furthermore, since a laser passing space SP is formed so as to be surrounded by the first protrusion 37, the second protrusion 38, the handle portion 39 and the transport chamber 36, the developing container 32 and the scanner unit 11 can be arranged in close proximity to each other, thereby making it possible to miniaturize the image forming apparatus 1.

[0076] Furthermore, when the toner pack 40 is attached to the supply port 32a and a toner supply operation is performed, the stirring member 34 is driven, so that the packing phenomenon can be reduced even if the supply port 32a is disposed on one end side in the longitudinal direction of the developing container 32. This reduces image defects and improves the detection accuracy of the remaining toner amount information by the light-emitting portion 51a and the light-receiving portion 51b.

[0077] <Second embodiment> Next, a second embodiment of the present invention will be described, which is a modification of the configuration of the developing device 30 in the first embodiment. Therefore, configurations similar to those in the first embodiment will be described by omitting illustrations or by assigning the same reference numerals in the drawings.

[0078] The developing device 330 according to the present embodiment will be described with reference to FIGS. 14 to 17. The developing device 330 constitutes a part of the process unit 20 (see FIG. 3). FIG. 14 is a perspective view showing the developing device 330. FIG. 15(a) is a perspective view showing the state in which the substrate 700 and the substrate holding member 710 are assembled to the developing container lid 321. FIG. 15(b) is a perspective view showing the substrate 700 and the substrate holding member 710, and FIG. 15(c) is another perspective view showing the substrate 700 and the substrate holding member 710. FIG. 16(a) is a cross-sectional view passing through the light-emitting portion 510a of the developing device 330, and FIG. 16(b) is a cross-sectional view taken along the line 16B-16B of FIG. 16(a). FIG. 17(a) is a cross-sectional view showing the developing container 320 in a state where the remaining amount of toner is small, and FIG. 17(b) is a cross-sectional view showing the developing container 320 in a state where the remaining amount of toner is large.

[0079] As shown in Fig. 14, the developing device 330 has a developing container 320 and a developing container lid 321, which are connected by a connecting portion 322. The developing container 320, the developing container lid 321, and the connecting portion 322 configure a frame 340 of the developing device 330. The frame 340 is provided with a transport chamber 36 (see Fig. 16(a)) that accommodates a developer containing toner (hereinafter, referred to as toner). The developing roller 31 is supported by the frame 340.

[0080] The developing container lid 321, which constitutes a part of the frame 340, has substrate positioning members 321a and 321b and substrate fixing members 321c and 321d, and an optical path guide 610 is provided between the substrate fixing members 321c and 321d of the developing container lid 321. The optical path guide 610 has a first guide portion 610a and a second guide portion 610b, and the first guide portion 610a guides light emitted from a light emitting portion 510a (described later) into the transport chamber 36 of the developing container 320. The second guide portion 610b guides light that has passed through the first guide portion 610a and the transport chamber 36 to a light receiving portion 510b (described later).

[0081] The substrate positioners 321a and 321b as positioning parts are disposed outside the substrate fixing parts 321c and 321d, respectively, in the longitudinal direction LD of the developing container 320, and have a boss shape protruding in a direction away from the developing container 320. The shape of the substrate positioners 321a and 321b is not limited to a boss shape, and may be any shape. The longitudinal direction LD of the developing container 320 is the same as the longitudinal direction LD of the process unit 20 (see FIG. 5(a)). Fixing tools such as screws can be screwed into the substrate fixing parts 321c and 321d.

[0082] 15A, in this embodiment, a substrate 700 and a substrate holding member 710 are assembled to the developing container lid 321. The substrate holding member 710 is assembled to the developing container lid 321 in a state where it is sandwiched between the developing container lid 321 and the substrate 700.

[0083] 15(b), the substrate 700 is provided on a surface facing the substrate holding member 710 and has a light emitting portion 510a and a light receiving portion 510b for detecting the amount of toner remaining in the transfer chamber 36. In this embodiment, an LED is used for the light emitting portion 510a, and a phototransistor that is turned on by light from the LED is used for the light receiving portion 510b, but this is not limiting. For example, a halogen lamp or a fluorescent lamp may be applied to the light emitting portion 510a, and a photodiode or an avalanche photodiode may be applied to the light receiving portion 510b.

[0084] The board 700 also has positioning holes 700a, 700b into which the board positioners 321a, 321b are inserted and engaged, and board fixing holes 700c, 700d through which screws that are screwed into the board fixing portions 321c, 321d can pass.

[0085] Similarly, the substrate holding member 710 has positioning holes 710a, 710b into which the substrate positioners 321a, 321b are inserted and engaged, and substrate fixing holes 710c, 710d through which the screws screwed into the substrate fixing parts 321c, 321d can pass. Furthermore, the substrate holding member 710 has a first hole 711a into which the first guide part 610a of the optical path guide 610 is inserted, and a second hole 711b into which the second guide part 610b of the optical path guide 610 is inserted. The first hole 711a and the second hole 711b have a cylindrical shape. The substrate holding member 710 as a holder holds the substrate 700.

[0086] Further, light shielding plates 710e and 710f are provided as shielding portions on the side of the substrate holding member 710 facing the substrate 700. The light shielding plates 710e and 710f are disposed between the light emitting portion 510a and the light receiving portion 510b in a state in which the substrate 700 and the substrate holding member 710 are attached to the developing container lid 321, and are provided in the vicinity of the substrate 700.

[0087] 14 to 16(a), the substrate holding member 710 is positioned relative to the developer container lid 321 by the substrate positioning members 321a and 321b of the developer container lid 321 penetrating and engaging with the positioning holes 710a and 710b. The substrate 700 is positioned relative to the developer container lid 321 by the substrate positioning members 321a and 321b of the developer container lid 321 penetrating and engaging with the positioning holes 700a and 700b. In this way, the substrate positioning members 321a and 321b are commonly used to position the substrate holding member 710 and the substrate 700, so that the substrate holding member 710 and the substrate 700 can be positioned with higher accuracy.

[0088] Furthermore, with the substrate holding member 710 and the substrate 700 positioned relative to the developing container lid 321, screws are inserted into the substrate fixing holes 700c, 700d, 710c, and 710d, and the screws are screwed into the substrate fixing portions 321c and 321d of the developing container lid 321. As a result, the substrate holding member 710 and the substrate 700 are fastened together to the developing container lid 321 by the screws, and the substrate holding member 710 and the substrate 700 are fixed to the developing container lid 321.

[0089] 14 to 16(b), when the substrate holding member 710 and the substrate 700 are assembled to the developing container lid 321, the first guide portion 610a of the optical path guide 610 is inserted into the first hole portion 711a of the substrate holding member 710. Then, the first guide portion 610a is positioned at a position close to the light-emitting portion 510a of the substrate 700. Similarly, the second guide portion 610b of the optical path guide 610 is inserted into the second hole portion 711b of the substrate holding member 710. Then, the second guide portion 610b is positioned at a position close to the light-receiving portion 510b of the substrate 700.

[0090] As described above, the substrate holding member 710 and the substrate 700 are accurately positioned on the developing container lid 321, so that the light emitted from the light emitting portion 510a is reliably guided by the first guide portion 610a. Then, the light guided by the first guide portion 610a to the transfer chamber 36 inside the developing container 320 is emitted from the first guide portion 610a in the longitudinal direction LD.

[0091] Then, the light traveling along the optical path Q2 inside the transport chamber 36 is guided by the second guide portion 610b to the outside of the developing container 320. Since the second guide portion 610b is disposed close to the light receiving portion 510b, the light emitted from the second guide portion 610b is reliably received by the light receiving portion 510b. This improves the accuracy of detection of the remaining toner amount by the light emitting portion 510a and the light receiving portion 510b.

[0092] Also, light shielding plates 710e and 710f are arranged between the light-emitting unit 510a and the light-receiving unit 510b and in a position close to the substrate 700. Therefore, the light emitted from the light-emitting unit 510a and directed toward the light-receiving unit 510b without passing through the first guide portion 610a and the second guide portion 610b is shielded by the light shielding plates 710e and 710f. In particular, in this embodiment, an LED element is used for the light-emitting unit 510a, and it is desired that the LED element has a weaker directivity than, for example, a bullet-shaped LED, and that the light that reaches the light-receiving unit 510b directly from the light-emitting unit 510a is shielded. Therefore, erroneous detection caused by the light that does not pass through the optical path Q2 being received by the light-receiving unit 510b is suppressed, and the detection accuracy of the remaining toner amount by the light-emitting unit 510a and the light-receiving unit 510b can be improved.

[0093] Here, the arrangement of the light-emitting unit 510a and the light-receiving unit 510b will be described in more detail. As shown in Figs. 16(a) and 16(b), the light-emitting unit 510a and the light-receiving unit 510b are arranged on the side surface 36a of the frame 340 opposite the developing roller 31. The light-emitting unit 510a and the light-receiving unit 510b are provided in the center of the transport chamber 36 in the longitudinal direction LD. More specifically, the light-emitting unit 510a and the light-receiving unit 510b are arranged in an area AR1 corresponding to the laser passing space SP in the longitudinal direction LD (see Fig. 9(b)). The light-emitting unit 510a is arranged between the supply port 32a and the center portion 31a of the developing roller 31 in the longitudinal direction LD. The dashed line in Fig. 16(b) indicates a position corresponding to the center portion 31a of the developing roller 31. The center portion 31a of the developing roller 31 is arranged between the light-emitting unit 510a and the light-receiving unit 510b in the longitudinal direction LD. In this way, by providing the light-emitting unit 510a and the light-receiving unit 510b in the central portion of the transport chamber 36, it is possible to effectively detect the remaining amount of toner in the transport chamber 36. That is, although the developer (toner) may be unevenly distributed at the ends of the transport chamber 36 in the longitudinal direction LD, the developer is less unevenly distributed in the central portion of the transport chamber 36, so that the actual remaining amount of toner can be detected.

[0094] The method of detecting the remaining toner amount is the same as that described in the first embodiment with reference to, for example, FIGS. 10 to 13. As shown in FIG. 16(a), the optical path Q2 is set to overlap the rotation locus T of the agitating member 34 when viewed in the axial direction of the rotation shaft of the agitating member 34. In other words, the light emitted from the light-emitting unit 510a passes through the inside of the conveying chamber 36 within the rotation locus of the agitating member 34 when viewed in the axial direction of the agitating member 34. The time during which the optical path Q2 is blocked by the toner conveyed by the agitating member 34 when the agitating member 34 makes one rotation, that is, the time during which the light-receiving unit 51b does not detect the light from the light-emitting unit 51a, varies depending on the remaining toner amount. The light receiving intensity at the light-receiving unit 51b also varies depending on the remaining toner amount. This allows the control unit 90 to determine the remaining toner amount level.

[0095] For example, as shown in Fig. 17(a), when there is a small amount of toner in the transport chamber 36 of the developing container 320, the time that the light receiving portion 510b receives light becomes longer and the intensity of the light received by the light receiving portion 510b becomes stronger, so it is determined that the remaining toner amount is low. On the other hand, as shown in Fig. 17(b), when there is a large amount of toner in the transport chamber 36 of the developing container 320, the time that the light receiving portion 510b receives light becomes shorter and the intensity of the light received by the light receiving portion 510b becomes smaller, so it is determined that the remaining toner amount is large. The display of the remaining toner amount level by the toner remaining amount panel 400 is as described in Figs. 13(a) to (d).

[0096] As described above, in this embodiment, the substrate holding member 710 and the substrate 700 are attached to the process unit 20 including the developing container 320 (or the transport chamber 36) that contains the toner, and the substrate 700 is provided with the light emitting portion 510a and the light receiving portion 510b. Therefore, the relative position of the optical path Q2 in the transport chamber 36 is constant, and the remaining amount of toner can be stably detected regardless of the positional accuracy of the process unit 20 with respect to the printer body 100.

[0097] In addition, since the relative position of the optical path Q2 in the transfer chamber 36 is constant, there is no need to design the light-emitting unit 510a, the light-receiving unit 510b, and the developing container 320 in consideration of the positional deviation between the transfer chamber 36 and the optical path Q2. Therefore, for example, there is no need to select optical elements by providing a margin for the amount of light of the light-emitting unit 510a, and this improves the design freedom of the light-emitting unit 510a, the light-receiving unit 510b, and the developing container 32, and reduces costs.

[0098] Furthermore, since the substrate positioning members 321a and 321b provided on the developing container lid 321 are commonly used to position the substrate holding member 710 and the substrate 700, the developing container lid 321, the substrate holding member 710, and the substrate 700 can be positioned with higher accuracy.

[0099] Furthermore, by interposing the substrate holding member 710 having the first guide portion 610a, the second guide portion 610b, and the light shielding plates 710e and 710f between the developing container lid 321 and the substrate 700, it is possible to reduce reception of light that does not pass through the optical path Q2 by the light receiving portion 510b. This reduces erroneous detection by the light receiving portion 510b, and improves the detection accuracy of the remaining toner amount by the light emitting portion 510a and the light receiving portion 510b.

[0100] In addition, the light emitting unit 510a and the light receiving unit 510b in this embodiment are arranged side by side in the longitudinal direction LD of the process unit 20, and are arranged on the same side (front side) of the transport chamber 36 as viewed in the longitudinal direction LD. Therefore, the light emitting unit 51a and the light receiving unit 510b can be arranged compactly. Furthermore, since the light emitting unit 510a and the light receiving unit 510b are collectively provided on the substrate 700, power can be easily supplied to the light emitting unit 510a and the light receiving unit 510b, and signals can be easily exchanged between the light emitting unit 510a and the light receiving unit 510b. Therefore, the process unit 20 can be made compact. A connector is provided on the substrate 700, and the connector and the control unit 90 provided on the printer main body 100 are connected by a cable. When attaching or detaching the process unit 20 to or from the printer main body 100, the cable and the connector are attached or detached.

[0101] <Other embodiments> In the above-described first embodiment, the toner remaining amount sensor 51 including the light-emitting portion 51a and the light-receiving portion 51b is installed in the developing device 30, but the light-emitting portion 51a and the light-receiving portion 51b may be provided on a substrate.

[0102] In the second embodiment described above, the substrate holding member 710 is provided between the developing container lid 321 and the substrate 700, but this is not limiting. That is, the substrate 700 may be directly attached to the developing container lid 321 without providing the substrate holding member 710.

[0103] In the second embodiment, the substrate positioning members 321a and 321b are provided on the developing container lid 321, and the substrate positioning members 321a and 321b engage with the positioning holes 710a and 710b of the substrate holding member 710 and the positioning holes 700a and 700b of the substrate 700, but this is not limited. For example, boss-shaped positioning members may be protruded from both side surfaces of the substrate holding member 710, and these may be engaged with holes provided in the developing container lid 321 and the substrate 700, respectively. For example, boss-shaped positioning members may be provided on the substrate 700, and these positioning members may be engaged with holes provided in the developing container lid 321 and the substrate holding member 710, respectively. In any case, the method and position for positioning the substrate 700 in the process unit 20 and the method and position for fixing the substrate 700 are not limited.

[0104] In addition, in any of the above-described embodiments, the light-emitting unit and the light-receiving unit are arranged side by side in the longitudinal direction LD, but this is not limiting. In other words, the light-emitting unit and the light-receiving unit may be arranged in any position as long as they are arranged on the side of the conveying chamber 36 opposite the developing roller 31.

[0105] In addition, in any of the embodiments described above, the optical paths Q1 and Q2 are arranged so as to overlap the rotation locus T of the stirring member 34 when viewed in the axial direction of the stirring member 34, but this is not limited thereto. That is, the optical paths Q1 and Q2 may be arranged so as not to overlap the rotation locus T of the stirring member 34.

[0106] In any of the above-described embodiments, the reading device 200 is provided above the printer body, but this is not limiting. That is, the image forming apparatus may be a printer that does not have a reading device. Also, the reading device may be a reading device equipped with an ADF (Auto Document Feeder) that feeds documents. [Explanation of symbols]

[0107] 1: image forming apparatus / 20: process unit / 21: image carrier (photosensitive drum) / 31: developer carrier (developing roller) / 31a: center / 32: frame (developing container) / 32a: supply port / 34: stirring member / 36: storage section (transport chamber) / 40: supply container (toner pack) / 51a, 510a: light emitting section / 51b, 510b: light receiving section / 100: printer body (device body) / 321a, 321b: positioning section (substrate positioning) / 340: frame / 610a: first guide section / second guide section / 700: substrate / 710: holder (substrate holding member) / 710e, 710f: shielding section (light shielding plate) / 711a: first hole section / 711b: second hole section / LD: longitudinal direction

Claims

1. In an image forming apparatus, A device body, a process unit mounted on the main body of the apparatus, the process unit including a frame constituting a storage section for storing a developer, a developer carrier supported by the frame and carrying the developer stored in the storage section, and a substrate; the substrate has a light emitting portion that emits light and a light receiving portion that receives the light that is emitted from the light emitting portion and passes through the inside of the housing portion, the process unit includes a holder for holding the substrate, and a positioning portion provided on the frame for determining a position of the holder relative to the frame; The positioning portion is configured to determine a position of the substrate relative to the frame.

1. An image forming apparatus comprising:

2. The positioning portion is a protrusion that protrudes from an outer surface of the frame body, The holder is provided with a hole configured to engage with the protrusion to determine a position of the holder relative to the frame; the position of the substrate relative to the frame is determined by a portion of the protrusion penetrating the hole of the holder engaging with the substrate; 2. The image forming apparatus according to claim 1,

3. the process unit has screws for fixing the substrate and the holder to the frame; The substrate and the holder are fastened together to the frame by the screws.

3. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

4. the process unit has a first guide portion provided on the frame body and guiding the light emitted from the light-emitting portion into the inside of the storage portion, and a second guide portion provided on the frame body and guiding the light that has passed through the first guide portion and the inside of the storage portion to the light-receiving portion, The holder has a first hole portion into which the first guide portion is inserted and a second hole portion into which the second guide portion is inserted.

4. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

5. the holder has a shielding portion disposed between the light-emitting portion and the light-receiving portion and configured to shield light emitted from the light-emitting portion and directed toward the light-receiving portion without passing through the first guide portion and the second guide portion; 5. The image forming apparatus according to claim 4.

6. the light emitting portion and the light receiving portion are disposed on a side of the frame opposite to the developer carrier in a direction intersecting a longitudinal direction of the developer carrier; 6. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

7. the light emitting portion and the light receiving portion are arranged side by side in a longitudinal direction of the developer carrier, 7. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

8. the process unit has an agitating member that rotates to agitate the developer contained in the container, The longitudinal direction is parallel to the axial direction of the rotation shaft of the stirring member.

8. The image forming apparatus according to claim 6, wherein the image forming apparatus is a recording medium.

9. The light emitted from the light emitting unit passes through the inside of the storage unit within a rotation trajectory of the stirring member when viewed in the axial direction.

9. The image forming apparatus according to claim 8,

10. the process unit further includes a supply port to which a supply container containing a developer can be detachably attached, the supply port being used for supplying the developer from the supply container to the containing section; 10. The image forming apparatus according to claim 1, wherein the first and second electrodes are arranged in a first direction.

11. the light emitting portion is disposed between the supply port and a center portion of the developer carrier in a longitudinal direction of the developer carrier; 11. The image forming apparatus according to claim 10.

12. the process unit further includes an image carrier to which the developer is supplied from the developer carrier; 12. The image forming apparatus according to claim 1, wherein the image forming apparatus is a multi-layered image forming apparatus.

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