Image forming device

Abstract

To provide an image forming apparatus that improves accuracy of detecting an amount of developer in a storage section.SOLUTION: An image forming apparatus has: an apparatus body; a process unit that includes a frame body constituting a storage section storing developer and is attached to the apparatus body; a detection unit that has a light emitting section emitting light and a light receiving section receiving the light emitted from the light emitting section and passing through the inside of the storage section, and outputs an output value according to an amount of developer stored in the storage section; and a display section that is in a first state when the output value output from the detection unit is equal to or less than a predetermined threshold, and in a second state different from the first state when the output value output from the detection unit is larger than the predetermined threshold. The threshold changes according to the number of sheets printed by the image forming apparatus.SELECTED DRAWING: Figure 18

Description

[Technical Field]

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

[0002] Generally, electrophotographic image forming apparatuses form images by transferring a toner image formed on the surface of a photosensitive drum onto a transfer material serving as a transfer medium. Known developer replenishment methods include a process cartridge method and a toner container replenishment method. The process cartridge method integrates a photosensitive drum and a developer container into a process cartridge, and when the developer runs out, the process cartridge is replaced with a new one. On the other hand, the toner container replenishment method replenishes toner from a toner container such as a toner pack or a toner bottle to the developer container when the toner runs out.

[0003] Conventionally, an image forming apparatus has been proposed that estimates the amount of toner remaining in a developer container based on the light-receiving time it takes for the light-receiving unit to receive detection light that is irradiated from the light-emitting unit and passes through the developer container (see Patent Document 1). The toner container is provided with a stirring member that stirs the toner, and the light-receiving time by the light-receiving unit increases as the amount of toner remaining in the toner container decreases. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-131479 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the image forming apparatus described in Patent Document 1, the fluidity of the toner in the developing container changes depending on how the image forming apparatus 1 is used. For example, the fluidity of the toner in a used image forming apparatus 1 is lower than that of a new image forming apparatus 1. When the fluidity of the toner changes, the timing at which the toner in the developing container blocks the detection light changes. For this reason, even if the amount of toner remaining in the developing container is the same, the light receiving time by the light receiving unit changes, which reduces the accuracy of detecting the amount of remaining toner.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an image forming apparatus that improves the accuracy of detecting the amount of developer in the container. [Means for solving the problem]

[0007] the detection unit has a light-emitting section that emits light and a light-receiving section that receives light emitted from the light-emitting section and that passes through the interior of the container, and outputs an output value corresponding to an amount of developer contained in the container; and a display section that goes into a first state when the output value output from the detection unit is equal to or less than a predetermined threshold value, and goes into a second state different from the first state when the output value output from the detection unit is greater than the threshold value, and the threshold value is set to a value corresponding to the number of prints of the image forming apparatus. is set to a first threshold value when the number of printed sheets is a first value, and is set to a second threshold value different from the first threshold value when the number of printed sheets is a second value greater than the first value. , characterized by:

[0008] The present invention also provides a process unit for an image forming apparatus, the process unit having an apparatus main body, an image carrier on which an image is carried, a frame constituting a storage section for storing developer, a developer carrier supported by the frame and configured to supply developer to an electrostatic latent image formed on the image carrier, thereby developing the electrostatic latent image, an agitating member that rotates to agitate the developer stored in the storage section, and a supply port capable of supplying developer to the storage section, the process unit being attached to the apparatus main body, a drive source that drives the agitating member, and a light-emitting element that emits light. a light-receiving portion that receives light emitted from the light-emitting portion and passed through the inside of the container portion, and outputs an output value corresponding to the amount of developer contained in the container portion; and a display portion that goes into a first state when the output value output from the detection unit is equal to or smaller than a predetermined threshold value, and goes into a second state different from the first state when the output value output from the detection unit is greater than the predetermined threshold value, wherein the threshold value is a value representing an operation rate of the drive source during a period from when the detection unit starts to detect the amount of developer until a predetermined time before the detection unit starts. is set to a first threshold value when the operation rate is a first operation rate, and is set to a second threshold value different from the first threshold value when the operation rate is a second operation rate that is greater than the first operation rate. , characterized by:

[0009] The present invention also provides an image forming apparatus, a process unit having an apparatus main body, an image carrier on which an image is carried, a frame body constituting a storage section for storing developer, a developer carrier supported by the frame body and for developing an electrostatic latent image formed on the image carrier by supplying developer to the electrostatic latent image, and a supply port capable of supplying developer to the storage section, the process unit being attached to the apparatus main body, a detection unit having a light-emitting section for emitting light and a light-receiving section for receiving light emitted from the light-emitting section and passing through the interior of the storage section, and outputting an output value corresponding to an amount of developer stored in the storage section, and a display section which goes into a first state when the output value output from the detection unit is equal to or less than a predetermined threshold value, and goes into a second state different from the first state when the output value output from the detection unit is greater than the threshold value, the threshold value being a value representing the degree of cohesion of the developer stored in the storage section is a first cohesion level, is set to a first threshold value, and is set to a second threshold value different from the first threshold value when the cohesion level is a second cohesion level higher than the first cohesion level. , characterized by:

[0010] The present invention also provides an image forming apparatus, comprising a process unit having an apparatus main body, an image carrier on which an image is carried, a frame body constituting a storage section for storing developer, a developer carrier supported by the frame body and for developing an electrostatic latent image formed on the image carrier by supplying developer to the electrostatic latent image, and a supply port through which developer can be supplied to the storage section, the process unit being attached to the apparatus main body, a detection unit having an light-emitting section for emitting light and a light-receiving section for receiving light emitted from the light-emitting section and passing through the interior of the storage section, the detection unit outputting an output value corresponding to the amount of developer stored in the storage section, and a display section configured to be able to transition between a first state and a second state different from the first state, wherein the display section enters the first state when the amount of developer stored in the storage section is a predetermined amount and the output value is a first output value, and also enters the first state when the amount of developer stored in the storage section is the predetermined amount and the output value is a second output value different from the first output value. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an image forming apparatus in which the accuracy of detecting the amount of developer in the container is improved. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1A is a cross-sectional view showing an image forming apparatus according to a first embodiment, and FIG. 1B is a perspective view showing the image forming apparatus. [Figure 2] FIG. 2A is a cross-sectional view showing the image forming apparatus, and FIG. 2B is a perspective view showing the image forming apparatus with the discharge tray open. [Figure 3] 1A is a perspective view showing an image forming apparatus in a state where a pressure plate of a reading device is closed, and FIG. 1B is a perspective view showing an image forming apparatus in a state where the pressure plate is open. [Figure 4] 1A is a perspective view showing a developing container and a toner pack, FIG. 1B is a front view showing the developing container and the toner pack, and FIG. 1C is a perspective view showing an agitating member in the developing container. [Figure 5] (a) is a cross-sectional view taken along line 5A-5A in FIG. 4(b), and (b) is a cross-sectional view taken along line 5B-5B in FIG. 4(b). [Figure 6] FIG. [Figure 7] 1A is a front view showing a toner pack, FIG. 1B is a front view showing a first modified example of the toner pack, and FIG. 1C is a front view showing a second modified example of the toner pack. [Figure 8] FIG. [Figure 9] 1A is a perspective view showing the state in which the substrate and the substrate holding member are assembled 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 10] (a) is a cross-sectional view of the developing device, and (b) is a cross-sectional view of (a) taken along line 10B-10B. [Figure 11] FIG. 4 is a circuit diagram showing a remaining toner amount sensor. [Figure 12] FIG. 2 is a block diagram showing a control system of the image forming apparatus. [Figure 13] (a) is a perspective view showing the toner remaining amount panel indicating the NearOut level, (b) is a perspective view showing the toner remaining amount panel indicating the Low level, (c) is a perspective view showing the toner remaining amount panel indicating the Mid level, and (d) is a perspective view showing the toner remaining amount panel indicating the Full level. [Figure 14] 14(a) is a cross-sectional view taken along line 5B-5B of FIG. 4(b), showing a state in which the amount of toner remaining in the developing container is low. FIG. 14(b) is a cross-sectional view taken along line 5B-5B of FIG. 4(b), showing a state in which the amount of toner remaining in the developing container is low and the rotation phase of the agitating member is different from that in FIG. 14(a). [Figure 15] 4(b) sectional view taken along line 5B-5B of FIG. 4(b), showing a state in which the amount of toner remaining in the developing container is large and the rotation phase of the agitator is the same as that in FIG. 14(a). FIG. 4(b) sectional view taken along line 5B-5B of FIG. 4(b) showing a state in which the amount of toner remaining in the developing container is small and the degree of toner cohesion is high. [Figure 16] 10 is a graph showing a detected voltage when the remaining toner sensor detects light during one rotation of the stirring member. [Figure 17] 10 is a graph showing the change in the degree of toner cohesion with respect to the number of printed sheets. [Figure 18]10 is a graph showing the relationship between the remaining amount of toner and the detection time of the remaining toner sensor. [Figure 19] FIG. 10 is a block diagram showing a control system of an image forming apparatus according to a second embodiment. [Figure 20] 10 is a graph showing the relationship between motor rotation time and toner cohesion. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, exemplary embodiments for carrying out the present invention will be described with reference to the drawings. However, the dimensions, materials, shapes, and relative positions of the components described in the following embodiments may be changed as appropriate depending on the configuration of the device to which the invention is applied and various conditions, and the scope of the present invention is not intended to be limited to the following embodiments.

[0014] 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 cardboard, plastic film such as sheets for overhead projectors, sheets of special shapes such as envelopes and index paper, and cloth.

[0015] [Overall configuration] 1(a) and 1(b), the image forming apparatus 1 has a printer main body 100 as the device 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.

[0016] 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 (developer image) formed on a photosensitive drum 21 of the process unit 20 to a recording material. As shown in FIGS. 5(a) and 5(b), the process unit 20 includes the 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 main body 100. Note that the process unit 20 may be fastened to the printer main body 100 with screws, and may be removed primarily by a service technician rather than a user. However, the process unit 20 does not include structural components of the printer main body 100, such as the housing frame of the printer main body 100.

[0017] 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 chargeable organic photosensitive member on a drum-shaped base body made of aluminum. The photosensitive drum 21, which serves as an image carrier, is rotated by a motor in a predetermined direction (clockwise in the drawing) at a predetermined process speed.

[0018] The charging roller 22 contacts 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, thereby uniformly charging 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.

[0019] The scanner unit 11, which serves 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, for example, be 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.

[0020] The developing device 30 includes a developing roller 31 as a developer carrier that carries developer, a developing container 32 as a frame of the developing device 30, and a supply roller 33 that can supply 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 the 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 configuration can supply a sufficient amount of toner to the developing roller 31.

[0021] The developing device 30 of this embodiment uses a contact development method. That is, a toner layer carried on 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 on the developing roller 31 is transferred from the developing roller 31 to the drum surface in accordance with the potential distribution on the surface of the photosensitive drum 21, thereby developing the electrostatic latent image into a toner image. Note that this embodiment employs a reversal development method. That is, a toner image is formed by the toner adhering to the surface area of ​​the photosensitive drum 21, which has been charged in a charging process and then exposed in an exposure process, where the charge amount has attenuated.

[0022] In this embodiment, a toner having a particle size of 6 μm and a normal negative charge polarity is used. As an example, the toner used in this embodiment is a polymerized toner produced by a polymerization method. The toner used in this embodiment does not contain a magnetic component, and is a so-called non-magnetic single-component developer in which the toner is carried on the developing roller 31 mainly by intermolecular forces and electrostatic forces (image forces). However, a single-component developer containing a magnetic component may also be used. In addition to toner particles, a single-component developer may contain additives (e.g., wax or silica particles) to adjust the fluidity and charging performance of the toner. A two-component developer composed of a non-magnetic toner and a magnetic carrier may also be used. When a magnetic developer is used, a cylindrical developing sleeve with a magnet disposed inside is used as the developer carrier.

[0023] 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), thereby agitating the toner in the developing container 32 and transporting the toner toward the developing roller 31 and the supply roller 33. The agitating member 34 also circulates toner that has not been used for development and has been scraped off from the developing roller 31 within the developing container, thereby homogenizing the toner in the developing container. The agitating member 34 is not limited to a rotating type. For example, an agitating member that oscillates may be used. Furthermore, in addition to the agitating member 34, another agitating member may be provided.

[0024] A developing blade 35 is disposed at the opening of the developing container 32 in which the developing roller 31 is disposed, to regulate the amount of toner carried by the developing roller 31. The toner supplied to the surface of the developing roller 31 passes through the area 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.

[0025] 1(a) and 1(b), the feeding section 60 has a front door 61 supported by the printer main body 100 so as to be able to open and close, a tray section 62, a middle plate 63, a tray spring 64, and a pickup roller 65. The tray section 62 forms 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 able to move up and down. The tray spring 64 urges the middle plate 63 upward, pressing the recording material P loaded on the middle plate 63 against the pickup roller 65. Note that the front door 61 closes the recording material storage space when closed relative to the printer main body 100, and supports the recording material P together with the tray section 62 and middle plate 63 when open relative to the printer main body 100.

[0026] The fixing unit 70 is a thermal fixing unit 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 presses against the fixing film 71.

[0027] 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, the image forming process is started by the image forming unit 10 based on image information input from an external computer or 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 pre-charged by the charging roller 22, and an electrostatic latent image is formed on the photosensitive drum 21 by the irradiation of 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.

[0028] In parallel with the image forming process described above, 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 any skew is corrected by the recording material P hitting the nip of the pair of registration rollers 15. The pair of registration rollers 15 is then driven in synchronization 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.

[0029] 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 onto the recording material P being conveyed by a pair of registration rollers 15. The recording material P with the transferred toner image is conveyed to a fixing section 70, and 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 melts the toner particles and then solidifies them, thereby fixing the toner image to the recording material P. After passing through the fixing section 70, the recording material P is discharged to the outside of the image forming apparatus 1 (outside the machine) by a pair of discharge rollers 80, and is stacked on a discharge tray 81 formed at the top of the printer main body 100.

[0030] The discharge tray 81 is inclined upward toward the downstream side in the discharge direction of the recording material, and the recording material discharged onto the discharge tray 81 slides down the discharge tray 81 so that its rear end is aligned by a regulating surface 84 .

[0031] 3(a) and 3(b), the reading device 200 has a reading unit 201 that incorporates a reading section (not shown) therein, and a pressure plate 202 that is openably and closably supported by the reading unit 201. On the top 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.

[0032] When a user wants to have the image of a document read by the reading device 200, the user places the document on the document glass 203 with the pressure plate 202 open. Then, by closing the pressure plate 202, the document on the document glass 203 is prevented from shifting position, and a reading command is output to the image forming device 1 by operating, for example, the operation unit 300. 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-right direction with the operation unit 300 of the image forming device 1 facing forward. The reading unit emits light toward the document from the light-emitting unit, receives light reflected by the document with the light-receiving unit, and reads the image of the document by photoelectrically converting the light. Note that, hereinafter, the front-rear direction, left-right direction, and up-down direction are defined based on the state in which the operation unit 300 is facing forward.

[0033] As shown in FIGS. 2(a) and 2(b), a first opening 101 that opens upward is formed in the upper part of the printer main body 100 and is covered by a discharge tray 81. The discharge tray 81 is supported on the printer main body 100 so as to be openable and closable around a rotation axis that extends in the left-right direction. The discharge tray 81 opens from the front side toward the back side when the reading device 200 is opened relative to the printer main body 100. The first opening 101 is configured to expose a mounting section 57 having a refill port 32a into which a toner pack 40, which will be described later, can be attached (see FIGS. 4(a) and 4(b)). A user can access the mounting section 57 by opening the discharge tray 81. The reading device 200 and the discharge tray 81 may be configured to be held in an open state and a closed state by a holding mechanism such as a hinge mechanism.

[0034] In this embodiment, as shown in FIG. 1B , an opening / closing member 83 is provided on the discharge tray 81 so as to be openable and closable around a pivot shaft extending in the front-rear direction. An opening 81a is formed in the discharge tray 81, which opens upward. The opening / closing member 83 is configured to be movable between a closed position where it covers the supply port 32a to prevent the toner pack 40 from being attached to the developing container 32, and an open position where it exposes the supply port 32a 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 part of the discharge tray 81. The opening / closing member 83 and the opening 81a are formed on the left side of the discharge tray 81. The open / close member 83 is opened to the left by a user placing his / her finger in a groove 81b provided in the discharge tray 81. Therefore, the 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 match the shape of the discharge tray 81.

[0035] In this embodiment, a direct replenishment method is employed in which the user replenishes toner from a toner pack 40 (see FIGS. 1(a) and 1(b)) filled with replenishment toner to the developing device 30 while the developing device 30 remains attached to the image forming apparatus 1. This eliminates the need to remove the process unit 20 from the printer main body 100 and replace it with a new process unit when the toner level in the process unit 20 becomes low, thereby improving usability. Furthermore, the direct replenishment method allows toner to be replenished to the developing container 32 more inexpensively than replacing the entire process unit 20. Furthermore, the direct replenishment method reduces costs compared to replacing only the developing device 30 of the process unit 20 because it does not require replacing various rollers, gears, etc. The image forming apparatus 1 and the toner pack 40 constitute an image forming system.

[0036] [Recovery of residual toner after transfer] This embodiment employs a cleanerless configuration in which 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 residual toner is removed through the following process. The residual toner includes a mixture of positively charged toner and negatively charged toner that does not have a sufficient charge. The pre-exposure device 23 neutralizes the photosensitive drum 21 after transfer, and the charging roller 22 uniformly discharges the toner, thereby re-charging the residual toner to a negative polarity. The residual toner, re-charged to a negative polarity in the charging section, reaches the developing section as the photosensitive drum 21 rotates. The surface area of ​​the photosensitive drum 21 that has passed through the charging section is then exposed by the scanner unit 11, with the residual toner still adhering to the surface, and an electrostatic latent image is written onto the surface.

[0037] Here, the behavior of the transfer residual toner that has reached the development unit will be explained separately for the exposed and non-exposed areas of the photosensitive drum 21. The transfer residual toner adhering to the non-exposed area of ​​the photosensitive drum 21 is transferred to the development roller 31 in the development unit due to the potential difference between the potential of the non-exposed area (dark area potential) of the photosensitive drum 21 and the development voltage, and is then collected in the development container 32. This is because the normal charge 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 area. The toner collected in the development container 32 is stirred and dispersed with the toner in the development container by the stirring member 34, and is then carried by the development roller 31 and used again in the development process.

[0038] On the other hand, the transfer residual toner adhering to the exposed portion of the photosensitive drum 21 does not transfer from the photosensitive drum 21 to the developing roller 31 at the developing portion, but remains on the drum surface. 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.

[0039] As described above, the present embodiment employs a cleanerless configuration in which the transfer residual toner is collected in the developing device 30 and reused, but a conventionally known configuration in which the transfer residual toner is collected using a cleaning blade that contacts the photosensitive drum 21 may also be used. In this 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, installation space for a collection container for collecting transfer residual toner and the like is not required, 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.

[0040] [Configuration of the developer container and toner pack] Next, the configurations of the developing container 32 and the toner pack 40 serving as a supply container will be described. Fig. 4(a) is a perspective view showing the developing container 32 and the toner pack 40, and Fig. 4(b) is a front view showing the developing container 32 and the toner pack 40. Fig. 4(c) is a perspective view showing the stirring member 34 in the developing container 32. Fig. 5(a) is a cross-sectional view taken along line 5A-5A in Fig. 4(b), and Fig. 5(b) is a cross-sectional view taken along line 5B-5B in Fig. 4(b).

[0041] As shown in FIGS. 4(a) to 5(b), the developing container 32, which is a part of the developing device 30, has a transport chamber 36 that houses an agitating member 34. The transport chamber 36, which serves as a storage section that stores developer containing toner (hereinafter referred to as toner), extends over the entire length of the developing container 32 in the longitudinal direction LD (left-right direction). The developing container 32, which serves as a frame, has a developing container frame 320 and a developing container lid 321, and the developing container frame 320 and the developing container lid 321 are connected by a connecting portion 322. The developing roller 31 and the supply roller 33 are rotatably supported by the developing container frame 320.

[0042] The developing container 32 also has a supply protrusion 37 that protrudes upward from one end of the conveying chamber 36 in the longitudinal direction LD and communicates with the conveying chamber 36. More specifically, the supply protrusion 37 is provided at one end of the developing container lid 321 in the rotational axis direction (longitudinal direction LD) of the developing roller 31, and protrudes further than the center of the developing container 32 toward the discharge tray 81 in a direction intersecting the rotational axis direction.

[0043] In this embodiment, the supply protrusion 37 is hollow and is disposed on the left side of the developing container 32. An attachment portion 57 to which the toner pack 40 can be attached is provided at the end of the supply protrusion 37, and a rotatable supply port 32a is disposed in the attachment portion 57 so that the developer can be replenished from the toner pack 40 to the conveying 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 image forming apparatus 1.

[0044] The supply protrusion 37 extends obliquely from the transport chamber 36 toward the front and upward of the apparatus. That is, the supply protrusion 37 protrudes toward the downstream and upward in the discharge direction of the discharge roller pair 80. Therefore, the supply port 32a arranged in the supply protrusion 37 is arranged on the front side of the image forming apparatus 1, making it easy to supply toner to the developing container 32. Furthermore, by providing the supply protrusion 37 where the supply port 32a is arranged on one side in the longitudinal direction of the developing container 32, it is possible to ensure a laser passage space through which the laser emitted from the scanner unit 11 can pass, and the image forming apparatus 1 can be made more compact.

[0045] As shown in FIGS. 4A to 5B, the toner pack 40 is configured to be detachably attached to the mounting portion 57 of the supply protrusion 37. The toner pack 40 also has an openable / closable shutter member 41 and a groove 42 formed in correspondence with the protrusion 32b formed on the mounting portion 57. When replenishing toner into the developing container 32, the user aligns the groove 42 of the toner pack 40 so that it passes through the protrusion 32b of the mounting portion 57, and then connects the toner pack 40 to the mounting portion 57. Then, in this state, when the shutter member 41 of the toner pack 40 is rotated 90 degrees via a lever (not shown) provided on the image forming apparatus 1, the supply opening 32a also rotates in accordance with the shutter member 41. When this occurs, the lever or the shutter member 41 abuts against an abutment portion (not shown) of the mounting portion 57, completely opening the shutter member 41, and simultaneously connecting the supply opening 32a to the opening of the toner pack 40. As a result, the toner contained in the toner pack 40 leaks out from the opening of the toner pack 40, and the leaked toner passes through the replenishing port 32a and the hollow replenishing protrusion 37 and enters the transport chamber .

[0046] As shown in FIG. 4(c), the agitating member 34 has an agitating shaft 34a extending in the longitudinal direction LD, and a first blade portion 34b1 and a second blade portion 34b2 extending radially outward from the agitating shaft 34a. The first blade portion 34b1 and the second blade portion 34b2 are both formed of flexible sheets and have different lengths of extension radially outward. The first blade portion 34b1 is longer than the second blade portion 34b2. In FIGS. 5(a) and 5(b), the rotation trajectory of the first blade portion 34b1 is shown as rotation trajectory Tb1, assuming that the first blade portion 34b1 rotates in a straight state, ignoring the wall surface of the developing container 32. 5(a) and 5(b) show, as a rotation trajectory Tb2, a rotation trajectory of the second blade portion 34b2 when it is assumed that the second blade portion 34b1 rotates in a straight extended state, ignoring the wall surface of the developing container 32. The wiping portion 34c and the auxiliary wiping portion 34d of the agitating member 34 shown in FIG. 4(c) will be described later.

[0047] As shown in FIG. 5A, toner supplied from the supply port 32a, which is located upstream of the agitator 34 in the conveying direction, is sent toward the developing roller 31 and the supply roller 33 as the agitator 34 rotates. The supply port 32a and the supply protrusion 37 are located at one end of the developer container 32 in the longitudinal direction LD, and repeated rotation of the agitator 34 distributes the toner throughout the entire length of the developer container 32. In other words, the conveying direction of the agitator 34 is parallel to the longitudinal direction LD of the developer container 32 (see FIG. 4A) and also intersects with the longitudinal direction LD (the direction from the conveying chamber 36 toward the developing roller 31 and the supply roller 33). Here, as shown by the rotation loci Tb1 and Tb2, the first blade portion 34b1, which is the longer blade portion, functions as a main portion that conveys toner toward the developing roller 31 and the supply roller 33. On the other hand, the second blade portion 34b2, which is the shorter blade portion, functions as an auxiliary portion for transporting toner at, for example, the corner portion 36e of the transport chamber 36, which the first blade portion 34b1 cannot transport properly due to contact with the bottom portion.

[0048] In this embodiment, the toner pack 40 is configured as a bag made of easily deformable plastic film, as shown in FIGS. 6 and 7(a), but is not limited thereto. For example, the toner pack may be configured as a substantially cylindrical bottle container 40B as shown in FIG. 7(b), or as a paper container 40C as shown in FIG. 7(c). In either case, the toner pack (supply container) may be made of any material and any shape. Furthermore, the toner is preferably discharged from the toner pack by squeezing the toner pack 40 or the paper container 40C with the user's fingers, while the toner is preferably discharged from the bottle container 40B by vibrating the container, such as by tapping the container. A discharge mechanism may also be provided within 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 driving force from the printer main body 100.

[0049] Furthermore, the shutter member 41 may be omitted in either toner pack, or a sliding shutter member may be used instead of the rotating shutter member 41. The shutter member 41 may be configured to be destroyed when the toner pack is attached to the replenishing port 32a or when the toner pack is rotated while attached, or may have a removable lid structure such as a seal.

[0050] Furthermore, in this embodiment, the stirring member 34 is provided with two blade portions 34b1 and 34b2 having different lengths, but the length and number of the blade portions are not limited to this. For example, they may be freely set in consideration of the shape of the developing container 32, transport efficiency, etc.

[0051] [Toner remaining sensor] Next, the configuration of the toner remaining amount sensor 500 that detects the amount of toner remaining in the developing container 32 will be described with reference to FIGS. 8 to 11. FIG. 8 is a perspective view showing the developing device 30. FIG. 9(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. 9(b) is a perspective view showing the substrate 700 and the substrate holding member 710, and FIG. 9(c) is another perspective view showing the substrate 700 and the substrate holding member 710. FIG. 10(a) is a cross-sectional view passing through the light-emitting element 510a of the developing device 30, and FIG. 10(b) is a cross-sectional view taken along line 10B-10B of FIG. 10(a). FIG. 11 is a circuit diagram showing an example of the circuit configuration of the toner remaining amount sensor 500.

[0052] As shown in FIG. 8, the developer container lid 321, which constitutes a part of the developer container 32, has substrate positioning members 321a and 321b and substrate fixing members 321c and 321d. A light guide member 600 is installed between the substrate fixing members 321c and 321d of the developer container lid 321. The light guide member 600 has a first light guide member 610 and a second light guide member 620. The first light guide member 610 extends toward a light-emitting element 510a (described later), and the second light guide member 620 extends toward a light-receiving element 510b (described later). The first light guide member 610 guides light emitted from the light-emitting element 510a into the transfer chamber 36 of the developer container 32. The second light guide member 620 guides light that has passed through the first light guide member 610 and the transfer chamber 36 to the light-receiving element 510b. The light guide member 600, the light emitting element 510a as the light emitting portion, and the light receiving element 510b as the light receiving portion are collectively referred to as the remaining toner amount sensor 500 as a detection unit.

[0053] The substrate positioning members 321a and 321b are disposed outside the substrate fixing portions 321c and 321d, respectively, in the longitudinal direction LD of the developing container 32, and have boss shapes that protrude in a direction away from the developing container 32. The shapes of the substrate positioning members 321a and 321b are not limited to boss shapes and may be any shape. The longitudinal direction LD of the developing container frame 320 is the same as the longitudinal direction LD of the process unit 20 (see FIG. 4(a)). Fixing members such as screws can be threaded into the substrate fixing portions 321c and 321d.

[0054] 9(a), in the present embodiment, a substrate 700 and a substrate holding member 710 are assembled to the developer container lid 321. The substrate holding member 710 is assembled to the developer container lid 321 in a state where it is sandwiched between the developer container lid 321 and the substrate 700. That is, the substrate holding member 710 is disposed between the developer container lid 321 and the substrate 700. At this time, the substrate holding member 710 covers the surface 510c of the substrate 700 on which the light-emitting element 510a and the light-receiving element 510b are attached. This prevents foreign matter such as dust and toner from adhering to the surface 510c and prevents service personnel and the like from touching the surface 510c.

[0055] As shown in FIG. 9(b), the substrate 700 is provided on a surface facing the substrate holding member 710 and has a light-emitting element 510a and a light-receiving element 510b for detecting the amount of toner remaining in the transfer chamber 36. The light-emitting element 510a and the light-receiving element 510b are arranged side by side in the longitudinal direction LD of the process unit 20. Light emitted from the light-emitting element 510a passes through the interior of the transfer chamber 36 and is received by the light-receiving element 510b. That is, the light-emitting element 510a and the light-receiving element 510b form an optical path Q (see FIG. 10(a)) within the transfer chamber 36. The optical path Q extends in the longitudinal direction LD. In this embodiment, the light-emitting element 510a and the light-receiving element 510b are arranged on the substrate 700, but this is not limiting. For example, the light-emitting element 510a and the light-receiving element 510b may each be arranged inside the transport chamber 36, or the light-emitting element 510a and the light-receiving element 510b may each be arranged on the outer surface of the developing container 32, and light may be guided inside and outside the transport chamber 36 by a light-guiding section.

[0056] In addition, in this embodiment, an LED is used as the light-emitting element 510a, and a phototransistor that is turned on by light from the LED is used as the light-receiving element 510b, but this is not limiting. For example, a halogen lamp or a fluorescent lamp may be used as the light-emitting element 510a, and a photodiode or an avalanche photodiode may be used as the light-receiving element 510b. In addition, a cable connector 700n is provided on the substrate 700, and the cable connector 700n is connected to a control unit 90 (described later, see FIG. 12) provided in the printer main body 100 via a cable (not shown).

[0057] The board 700 also has positioning holes 700a and 700b into which the board positioning members 321a and 321b are inserted and engaged, and board fixing holes 700c and 700d through which screws that are screwed into the board fixing portions 321c and 321d can pass.

[0058] Similarly, the substrate holding member 710 has positioning holes 710a and 710b into which the substrate positioning members 321a and 321b are inserted and engage, and substrate fixing holes 710c and 710d through which screws that are screwed into the substrate fixing members 321c and 321d can pass. Furthermore, the substrate holding member 710 has a first through-hole 711a into which the first light guide portion 610 of the light guide member 600 is inserted, and a second through-hole 711b into which the second light guide portion 620 of the light guide member 600 is inserted. The substrate holding member 710 has a first opposing surface 710h that faces the developer container lid 321, and a first cylindrical portion 711c and a second cylindrical portion 711d that extend from the first opposing surface 710h toward the developer container lid 321. The first cylindrical portion 711c and the second cylindrical portion 711d each have a cylindrical shape and define a first through-hole portion 711a and a second through-hole portion 711b. The substrate holding member 710 abuts against the substrate 700.

[0059] Furthermore, light-shielding plates 710e and 710f are provided on the side of the substrate holding member 710 facing the substrate 700. These light-shielding plates 710e and 710f are disposed between the light-emitting element 510a and the light-receiving element 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.

[0060] 8 to 10(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 developer container lid 321, the substrate holding member 710, and the substrate 700 can be positioned with higher accuracy.

[0061] 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.

[0062] As shown in FIGS. 8 to 10(b), when the substrate holding member 710 and the substrate 700 are assembled to the developing container lid 321, the first light guide portion 610 of the light guide member 600 is inserted into the first through-hole portion 711a of the substrate holding member 710. The first light guide portion 610 is then positioned in proximity to the light-emitting element 510a of the substrate 700. Similarly, the second light guide portion 620 of the light guide member 600 is inserted into the second through-hole portion 711b of the substrate holding member 710. The second light guide portion 620 is then positioned in proximity to the light-receiving element 510b of the substrate 700. The first through-hole portion 711a covers the side surface 611 of the first light guide portion 610 inserted into the first through-hole portion 711a between the developing container lid 321 and the light-emitting element 510a. Similarly, the second through-hole 711b covers the side surface 621 of the second light guide 620 inserted into the second through-hole 711b between the developing container lid 321 and the light receiving element 510b. This makes it possible to prevent light other than the light emitted from the light emitting element 510a from entering the first light guide 610 or the second light guide 620, thereby improving the accuracy of detecting the remaining toner amount.

[0063] 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 element 510a is reliably guided by the first light guide portion 610. Then, the light guided by the first light guide portion 610 to the transfer chamber 36 inside the developing container frame 320 is emitted from the light emitting window 612a of the first light guide portion 610 toward the longitudinal direction LD.

[0064] Then, light traveling along the optical path Q inside the transfer chamber 36 enters the light receiving window 622a of the second light guide portion 620 and is guided to the outside of the developing container frame 320 by the second light guide portion 620. Because the second light guide portion 620 is disposed close to the light receiving element 510b, the light emitted from the second light guide portion 620 is reliably received by the light receiving element 510b. This improves the accuracy of detecting the remaining toner amount by the light emitting element 510a and the light receiving element 510b.

[0065] 9(b) and 9(c), light-shielding plates 710e and 710f are disposed between the light-emitting element 510a and the light-receiving element 510b and in a position close to the substrate 700. The substrate holding member 710 has a second opposing surface 710g that faces the substrate 700. The light-shielding plates 710e and 710f are ribs that stand upright from the second opposing surface 710g so as to approach the substrate 700. Therefore, light emitted from the light-emitting element 510a and directed toward the light-receiving element 510b without passing through the first light guide portion 610 and the second light guide portion 620 is blocked by the light-shielding plates 710e and 710f. In particular, in this embodiment, an LED element is used as the light-emitting element 510a, which has weaker directionality than, for example, a bullet-shaped LED, and it is desirable to block light that reaches directly from the light-emitting element 510a to the light-receiving element 510b. Therefore, erroneous detection caused by light that does not pass through the optical path Q being received by the light receiving element 510b is suppressed, and the accuracy of detection of the remaining toner amount by the light emitting element 510a and the light receiving element 510b can be improved.

[0066] The arrangement of the light-emitting element 510a and the light-receiving element 510b will now be described in more detail. As shown in FIGS. 10(a) and 10(b), the light-emitting element 510a and the light-receiving element 510b are arranged on the side surface 36a of the developer container 32 opposite the developing roller 31 in a direction perpendicular to the longitudinal direction of the developing roller 31. The light-emitting element 510a and the light-receiving element 510b are also provided in the central portion of the transport chamber 36 in the longitudinal direction LD. More specifically, the light-emitting element 510a and the light-receiving element 510b are arranged so that the center 31a (broken line) of the developing roller 31 is located between the light-emitting element 510a and the light-receiving element 510b. By providing the light-emitting element 510a and the light-receiving element 510b in the central portion of the transport chamber 36 in this way, the remaining toner amount in the transport chamber 36 can be detected accurately. That is, developer (toner) may be unevenly distributed at the ends of the transport chamber 36 in the longitudinal direction LD, but the developer is less unevenly distributed in the central part of the transport chamber 36, so the actual amount of remaining toner can be detected.

[0067] Here, the configuration of the agitating member 34 related to the light guide member 600 will be described. As shown in FIG. 4(c), the agitating member 34 has a wiping portion 34c including a light-emitting side wiping end 34c1 and a light-receiving side wiping end 34c2, and an auxiliary wiping portion 34d, at a position facing the light guide member 600 in the longitudinal direction LD. The auxiliary wiping portion 34d is disposed overlapping the wiping portion 34c. The wiping portion 34c and the auxiliary wiping portion 34d are flexible sheets. In addition, the rotation trajectory of the wiping portion 34c as viewed in the axial direction (longitudinal direction LD) of the agitating member 34 is set to overlap the optical path Q.

[0068] As the agitating member 34 rotates, the light-emitting side wiping end 34c1 passes through the light guide member 600 while rubbing against the light-emitting window 612a of the first light guide portion 610, and the light-receiving side wiping end 34c2 passes through the light guide member 600 while rubbing against the light-receiving window 622a of the second light guide portion 620. That is, with each rotation of the agitating member 34, the wiping portion 34c wipes away developer adhering to the light-emitting window 612a and the light-receiving window 622a. The auxiliary wiping portion 34d adjusts the contact pressure and angle of the wiping portion 34c with the light-emitting window 612a and the light-receiving window 622a, and is designed taking into consideration the shapes and positional relationship between the light guide member 600 and the agitating member 34. Note that if the wiping portion 34c alone can sufficiently wipe off developer, the auxiliary wiping portion 34d may be omitted. Furthermore, the wiping portion 34c may be omitted, and the blade portion of the agitating member 34 may be used to clean the light-emitting window 612a and the light-receiving window 622a of the light-guiding member 600.

[0069] As shown in the circuit diagram of remaining toner amount sensor 500 in Fig. 11, a switch (not shown) is provided between light-emitting element 510a and power supply voltage Vcc, and by turning on the switch, a voltage from power supply voltage Vcc is applied to light-emitting element 510a. This places light-emitting element 510a in a conductive state. Meanwhile, a switch (not shown) is also provided between light-receiving element 510b and power supply voltage Vcc, and by turning on the switch, light-receiving element 510b is placed in a conductive state by a current corresponding to the detected amount of light.

[0070] A power supply voltage Vcc and a current-limiting resistor R1 are connected to the light-emitting element 510a, and the light-emitting element 510a emits light using a current determined by the current-limiting resistor R1. Light emitted from the light-emitting element 510a travels along an optical path Q as shown in FIG. 10(b) and is received by the light-receiving element 510b. The collector terminal of the light-receiving element 510b is connected to the power supply voltage Vcc, and the emitter terminal is connected to a detection resistor R2. The light-receiving element 510b, which is a phototransistor, receives the light emitted from the light-emitting element 510a and outputs a signal as an output value corresponding to the time the light is received (detection time). This signal is converted to a voltage V1 by the detection resistor R2 and input to the A / D converter 95 of the control unit 90 (see FIG. 11). The time the light-receiving element 510b receives light during one rotation of the agitator 34 (detection time) is proportional to the time the optical path Q is open, and therefore becomes longer as the amount of toner remaining in the transfer chamber 36 decreases. That is, the remaining toner amount sensor 500 outputs an output value corresponding to the time when the light receiving element 510b receives light, in accordance with the amount of toner (amount of developer) contained in the transport chamber .

[0071] 11(a), the optical path Q of the remaining toner amount sensor 500 is set to overlap with the rotation loci Tb1 and Tb2 of the agitator 34 when viewed in the axial direction of the rotation shaft of the agitator 34. In other words, the light emitted from the light-emitting element 510a of the remaining toner amount sensor 500 passes through the inside of the conveying chamber 36 within the rotation loci Tb1 and Tb2 of the agitator 34 when viewed in the axial direction of the agitator 34 (longitudinal direction LD).

[0072] [Image forming device control system] 12 is a block diagram showing a control system of image forming apparatus 1. A control unit 90 serving as control means for image forming apparatus 1 has a CPU 91 as a calculation device, a RAM 92 used as a work area for 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 external devices, an A / D conversion unit 95 that converts analog signals into digital signals, and an image print number counter 97 that counts the number of image prints.

[0073] The input side of the control unit 90 is connected to the remaining toner amount sensor 51, the mounting sensor 53, and the open / close sensor 54. The mounting sensor 53 detects that the toner pack 40 has been 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 configured from a pressure-sensitive switch that outputs a detection signal when pressed by the toner pack 40. The open / close sensor 54 detects whether the open / close member 83 has been opened relative to the discharge tray 81. The open / close sensor 54 is configured from, for example, a pressure-sensitive switch or a magnetic sensor.

[0074] The CPU 91 of the control unit 90 determines whether the light-receiving element 510b has received light from the light-emitting element 510a based on the voltage level input to the toner remaining amount sensor 500. Then, the CPU 91 calculates the length of time during which the toner remaining amount sensor 500 detected light when the toner in the developing container 32 was stirred for a certain period of time by the stirring member 34. The ROM 93 pre-stores, as a table 96, toner remaining amount determination thresholds (hereinafter simply referred to as thresholds) for determining the amount of toner remaining from the light detection time of the toner remaining amount sensor 500. The CPU 91 calculates (predicts) the amount of toner remaining in the developing container 32 based on the light detection time of the toner remaining amount sensor 500 and the thresholds stored in the table 96.

[0075] The control unit 90 is also connected to an operation unit 300, the image forming unit 10, and a toner remaining amount panel 400 capable of displaying information regarding the amount of remaining toner. The operation unit 300 has a display unit 301 capable of displaying various setting screens, physical keys, etc. The display unit 301 is configured, for example, with a liquid crystal panel. The image forming unit 10 has a motor M1 as a drive source for driving the photosensitive drum 21, developing roller 31, supply roller 33, agitator 34, etc. Note that the photosensitive drum 21, developing roller 31, supply roller 33, and agitator 34 may each be driven by a separate motor.

[0076] 1(b) and 13(a) to (d), the remaining toner amount panel 400 is provided on the right side of the front of the housing of the printer main body 100, i.e., on the opposite side to the operation unit 300 located on the left side, and displays information related to the amount of toner remaining in the developing container 32. In this embodiment, the remaining toner amount panel 400 as a display unit 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.

[0077] That is, as shown in FIG. 13(a), when only the lower scale is flashing intermittently, the remaining toner amount in the developer container 32 indicates the NearOut level. At this time, the remaining toner amount in the developer container 32 is less than the first amount QT1 (see FIG. 18). As shown in FIG. 13(b), when only the lower scale is continuously lit, the remaining toner amount in the developer container 32 indicates the Low level. At this time, the remaining toner amount in the developer container 32 is equal to or greater than the first amount QT1 (see FIG. 18) and less than the second amount QT2. In other words, the remaining toner amount panel 400 can transition between a first state shown in FIG. 13(b) and a second state different from the first state shown in FIG. 13(a). As shown in FIG. 13(c), when the lower and central scales are lit and the upper scale is off, the remaining toner amount in the developer 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 is at the full level.

[0078] The NearOut level indicates the amount of remaining toner that will soon run out in the developer container 32, making it impossible to form an image properly. The Low level indicates the amount of remaining toner that is greater than the NearOut level and less than the Mid level. The Mid level indicates the amount of remaining toner that is greater than the Low level and less than the Full level.

[0079] The toner remaining amount panel 400 is not limited to a liquid crystal panel, and may be configured to include 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 this 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 prompt the user to replenish toner. When the toner runs out, a replenishment notice may be displayed on the operation unit 300 to prompt the user to replenish toner.

[0080] In addition, in the present embodiment, a 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. Furthermore, the remaining toner amount may be continuously displayed using a percentage or gauge display. Furthermore, the remaining toner amount may be notified to the user by voice using a speaker.

[0081] [Method for detecting remaining toner] Next, a method for detecting the amount of toner remaining in the developing container 32 will be described with reference to Figures 14(a) to 18. Figure 14(a) is a cross-sectional view taken along line 5B-5B of Figure 4(b) showing a state in which the amount of toner remaining in the developing container 32 is low. Figure 14(b) is a cross-sectional view taken along line 5B-5B of Figure 4(b) showing a state in which the amount of toner remaining in the developing container 32 is low and the rotation phase of the stirring member 34 is different from that shown in Figure 14(a). Figures 14(a) and 14(b) show a state in which the degree of toner cohesion, which will be described later, is low.

[0082] FIG. 15(a) is a cross-sectional view taken along line 5B-5B of FIG. 4(b) showing a state in which the amount of toner remaining in the developing container 32 is large and the rotational phase of the agitating member 34 is the same as that shown in FIG. 14(a). FIG. 15(b) is a cross-sectional view taken along line 5B-5B of FIG. 4(b) showing a state in which the amount of toner remaining in the developing container 32 is small and the degree of toner cohesion is high. FIG. 16 is a graph showing the detection voltage when the toner remaining sensor 500 detects light during one rotation of the agitating member 34. FIG. 17 is a graph showing the change in the degree of toner cohesion over the number of printed pages. FIG. 18 is a graph showing the relationship between the amount of toner remaining and the detection time of the toner remaining sensor.

[0083] 14(a) to 15(b), the toner in the developing container 32 moves and is stirred within the developing container 32 as the stirring member 34 rotates. The following description will focus particularly on the toner moved by the first blade portion 34b1 and the second blade portion 34b2 of the stirring member 34.

[0084] In the rotation phase of the agitator 34 shown in FIG. 14(a), the toner lifted by the first blade portion 34b1 and the second blade portion 34b2 begins to fall downward. At this time, the agitator 34 is positioned in the first rotation phase. Then, when the agitator 34 further rotates from the first rotation phase to the second rotation phase, the toner on the first blade portion 34b1 and the second blade portion 34b2 falls downward, as shown in FIG. 14(b). In the state shown in FIG. 14(a), light can pass through the optical path Q, i.e., the optical path Q is open and not blocked by toner. Therefore, the remaining toner sensor 500 can detect light.

[0085] 14(b), toner that has fallen downward from the first blade portion 34b1 and the second blade portion 34b2 blocks the light path Q, preventing the remaining toner amount sensor 500 from detecting light. As the agitating member 34 rotates from the first rotation phase to the second rotation phase, the remaining toner amount sensor 500 reaches a light-blocking timing Tc1 at which the light-receiving element 510b switches from a state in which it can detect light to a state in which it cannot, as shown in FIG. 16. When the amount of toner remaining in the developing container 32 is low, the time during which the remaining toner amount sensor 500 can detect light while the agitating member 34 makes one rotation is time T1.

[0086] 15(a) shows a state in which the amount of remaining toner in the developing container 32 is greater than in FIGS. 14(a) and 14(b), and the agitating member 34 is positioned at the first rotation phase. At this time, as shown in FIG. 15(a), even in a state in which the toner is lifted by the first blade portion 34b1 and the second blade portion 34b2, toner is present near the optical path Q. For this reason, as shown in FIG. 16, when the amount of remaining toner in the developing container 32 is large, the time during which the toner remaining sensor 500 can detect light while the agitating member 34 makes one rotation is time T0, which is shorter than time T1.

[0087] In this way, the time that the optical path Q is blocked by the toner transported by the agitating member 34 during one rotation of the agitating member 34, i.e., the time that the toner remaining amount sensor 500 cannot detect light, varies depending on the amount of remaining toner. In other words, when the amount of remaining toner in the developing container 32 is large, the optical path Q is more likely to be blocked by the toner, so the time that the toner remaining amount sensor 500 detects light becomes shorter, and conversely, when the amount of remaining toner is small, the time that the toner remaining amount sensor 500 detects light becomes longer.

[0088] Incidentally, as the cumulative number of image formations (number of image prints) in the image forming apparatus 1 increases, the toner in the developer container 32 loses fluidity. This is thought to be because the toner is subjected to mechanical stress by the developing roller 31 and the agitator 34, causing the toner's fluidizing agent to become embedded in the toner's binder. The toner is primarily composed of a binder, colorant, wax, charge control agent, and fluidizing agent. The binder is made of resin and has functions such as improving the fixation of images transferred to a recording material. Here, we will explain the degree of cohesion as an index of the fluidity of the toner in the developer container 32 (hereinafter simply referred to as toner fluidity).

[0089] [Cohesion] The degree of cohesion is an index that indicates how easily toner aggregates. When the degree of cohesion is high, the toner aggregates and has low fluidity. Conversely, when the degree of cohesion is low, the toner does not easily aggregate, and the toner fluidity is high. The degree of cohesion can be measured, for example, by the following method.

[0090] The measuring device is a Powder Tester (registered trademark) PT-D model manufactured by Hosokawa Micron Corporation. The measurement is performed as follows: First, three types of sieves are stacked on top of each other on the vibration table of the measuring device. The three types of sieves, from top to bottom, are a 200-mesh sieve with 75 μm mesh, a 390-mesh sieve with 38 μm mesh, and a 635-mesh sieve with 25 μm mesh. These are placed on the vibration table, and 5 g of toner is aged overnight in an environment of 23°C and 50% humidity. The vibration table is then vibrated with an amplitude of 0.6 mm for 15 seconds, and the toner remaining on each sieve is measured, and the degree of cohesion is calculated using the following formula. Mass % of toner remaining on the 75 μm sieve × 1 (a) Mass% of toner remaining on the 38 μm sieve × 0.6 (b) Mass% of toner remaining on the 25 μm sieve × 0.2 (c) Cohesion=(a)+(b)+(c) (%)

[0091] Figure 17 shows the change in toner cohesion with respect to the number of printed pages. As the number of printed images increases from the initial state, the cohesion increases. The image forming apparatus 1 of this embodiment uses a direct replenishment method in which toner is replenished directly into the developing container 32, and by replenishing toner, the cohesion of toner in the developing container 32 decreases compared to immediately before the toner was replenished. When only toner is replenished and the process unit 20 is used repeatedly, the cohesion of toner in the developing container 32 gradually increases.

[0092] The relationship between toner fluidity and toner remaining amount detection will be explained below. The previously described FIG. 14(a) shows a state in which toner cohesion is low. For comparison, FIG. 15(b) shows a state in which the toner amount in the developer container 32 is the same as in FIG. 14(a), the rotational phase of the agitator 34 is the same (first rotational phase), but the toner cohesion is high. Toner fluidity tends to be inversely proportional to toner cohesion. Even if the amount of toner in the developer container 32 is the same, if the toner fluidity is different, the timing at which the toner on the first blade portion 34b1 and the second blade portion 34b2 begin to fall downward will differ.

[0093] In the state of low toner cohesion shown in FIG. 14(a), toner fluidity is high, and toner accumulated on the first blade portion 34b1 and the second blade portion 34b2 tends to slide downward in the direction of gravity. On the other hand, in the state of high toner cohesion shown in FIG. 15(b), toner fluidity is low, and compared to the condition of high toner fluidity, toner accumulated on the first blade portion 34b1 and the second blade portion 34b2 tends to maintain its posture. Therefore, toner on the first blade portion 34b1 and the second blade portion 34b2 is less likely to slide downward in the direction of gravity. In other words, the timing at which toner on the first blade portion 34b1 and the second blade portion 34b2 begins to slide downward in the direction of gravity is later under the condition of low toner fluidity than under the condition of high toner fluidity.

[0094] As shown in FIG. 16, the light shielding timing at which the light receiving element 510b switches from a state where it can detect light to a state where it cannot detect light under conditions of low toner fluidity is the light shielding timing Tc2. The light shielding timing Tc2 is a timing later than the light shielding timing Tc1 under conditions of high toner fluidity. For this reason, the time during which the toner remaining amount sensor 500 can detect light while the stirring member 34 makes one revolution under conditions of low toner fluidity becomes a time T2 that is longer than the time T1. Note that the light transmission timing Tc3 at which the light receiving element 510b switches from a state where it cannot detect light to a state where it can detect light is assumed to be constant regardless of the toner fluidity. Also, in the above description, the times T1 and T2 have been described with regard to the toner moved by the first blade portion 34b1 and the second blade portion 34b2, but even when considering the toner moved by the wiping portion 34c and the wiping assist portion 34d, the relationship T1 < T2 does not change.

[0095] That is, even when the amount of toner in the developing container 32 is the same, if the toner fluidity is different, a difference occurs in the time during which the toner remaining amount sensor 500 detects light. Specifically, under conditions of high toner fluidity, the detection time of the toner remaining amount sensor 500 becomes shorter, and under conditions of low toner fluidity, the detection time of the toner remaining amount sensor 500 becomes longer.

[0096] In the present embodiment, a threshold value for determining the toner remaining amount from the detection time of the toner remaining amount sensor 500 is stored in the table 96 of the ROM 93. In the table 96, the threshold values for determining the toner remaining amount differ according to the number of image prints. For example, when the threshold value at the time of 5000 image prints from the initial state is set to 100%, the threshold value is set to 105% at the time of 10000 image prints and 110% at the time of 20000 image prints.

[0097] Here, line TV1 in FIG. 18 schematically shows the relationship between the remaining toner amount and the detection time of toner remaining sensor 500 when image forming apparatus 1 and process unit 20 are brand new. Line TV2 in FIG. 18 schematically shows the relationship between the remaining toner amount and the detection time of toner remaining sensor 500 in image forming apparatus 1 when 20,000 images have been printed. Note that the horizontal axis in FIG. 18 indicates the remaining toner amount, and the amount of toner remaining in developer container 32 decreases as the axis moves in the + direction (to the right). Also, the vertical axis in FIG. 18 indicates the detection time of toner remaining sensor 500, and the detection time increases as the axis moves in the + direction (upward). Table 96 stores Low thresholds V1a and V2a and NearOut thresholds V1b and V2b. 18, when the remaining toner amount is equal to or greater than the first amount QT1 and less than the second amount QT2, the remaining toner amount panel 400 indicates the Low level. When the remaining toner amount is less than the first amount QT1, the remaining toner amount panel 400 indicates the NearOut level.

[0098] In a brand new image forming apparatus 1 (see line TV1), when the detection time of toner remaining sensor 500 exceeds Low threshold V1a, controller 90 determines that the remaining toner amount is at Low level. Then, controller 90 controls toner remaining panel 400 to indicate Low level (see FIG. 13(b)). Also, in a brand new image forming apparatus 1, when the detection time of toner remaining sensor 500 exceeds NearOut threshold V1b, controller 90 determines that the remaining toner amount is at NearOut level. Then, controller 90 controls toner remaining panel 400 to indicate NearOut level (see FIG. 13(a)). In other words, when the detection time output from toner remaining sensor 500 is equal to or less than NearOut threshold V1b, which is a predetermined threshold, toner remaining panel 400 is at Low level (first state). Furthermore, when the detection time output from the remaining toner sensor 500 is greater than the NearOut threshold V1b, the remaining toner panel 400 is at the NearOut level (second state).

[0099] Similarly, in the image forming apparatus 1 (see line TV2) when the number of printed images reaches 20,000, if the detection time of the toner remaining sensor 500 exceeds the Low threshold V2a, the control unit 90 determines that the amount of remaining toner is at the Low level. Then, the control unit 90 controls the toner remaining panel 400 to indicate the Low level (see FIG. 13(b)). Also, in the image forming apparatus 1 when the number of printed images reaches 20,000, if the detection time of the toner remaining sensor 500 exceeds the NearOut threshold V2b, the control unit 90 determines that the amount of remaining toner is at the NearOut level. Then, the control unit 90 controls the toner remaining panel 400 to indicate the NearOut level (see FIG. 13(a)). In other words, if the detection time output from the toner remaining sensor 500 is equal to or less than the NearOut threshold V2b, the toner remaining panel 400 becomes the Low level (first state). Furthermore, when the detection time output from the remaining toner sensor 500 is greater than the NearOut threshold V2b, the remaining toner panel 400 is at the NearOut level (second state).

[0100] In this way, the control unit 90 changes the threshold value used to determine the remaining toner amount depending on the number of images printed by the image forming apparatus 1. In other words, the threshold value used to determine the remaining toner amount changes depending on the cohesion of the toner contained as the developer in the developing container 32. Specifically, as the number of images printed increases, the toner fluidity decreases (the toner cohesion increases). Even if the remaining toner amount remains the same, the lower the toner fluidity, the longer the detection time of the toner remaining sensor 500. For this reason, in this embodiment, the threshold value for determining the remaining toner amount is corrected to be higher as the number of images printed increases. For example, the low threshold value V2a used to determine whether the remaining toner amount is low when the image forming apparatus 1 has printed 20,000 images is higher than the low threshold value V1a used to determine whether the remaining toner amount is low when the image forming apparatus 1 is brand new. The NearOut threshold V2b used by the image forming device 1 to determine whether the remaining amount of toner is at the NearOut level when the number of printed images reaches 20,000 is greater than the NearOut threshold V1b used by a brand new image forming device 1 to determine whether the remaining amount of toner is at the NearOut level. In other words, when the number of printed images is a first value (e.g., 0), the NearOut threshold V1b is set as the first threshold, and when the number of printed images is a second value (e.g., 20,000) greater than the first value, the NearOut threshold V2b is set as the second threshold.

[0101] By correcting the threshold value for determining the remaining toner amount in accordance with the number of printed images in this manner, the amount of toner remaining in the developing container 32 can be calculated more accurately. For example, consider a case where the remaining toner amount contained in the developing container 32 is a predetermined third amount QT3. The third amount QT3 is equal to or greater than the first amount QT1 and less than the second amount QT2, which corresponds to a low level. In this case, in a brand new image forming apparatus 1 (see line TV1), the remaining toner sensor 500 outputs a detection time V1c as a first output value. On the other hand, in an image forming apparatus 1 at the time when 20,000 images have been printed (see line TV2), the remaining toner sensor 500 outputs a detection time V2c as a second output value different from the detection time V1c. Because the threshold values ​​for determining the remaining toner amount applied to the remaining toner panel 400 are different, the remaining toner panel 400 is at the low level (first state) in both the brand new image forming apparatus 1 and the image forming apparatus 1 at the time when 20,000 images have been printed. Therefore, even if the detection time output from the toner remaining amount sensor 500 differs due to differences in toner cohesion (toner fluidity), the accuracy of detecting the toner remaining amount in the developing container 32 can be improved by correcting the threshold value for determining the toner remaining amount.

[0102] The image forming apparatus 1 of this embodiment is a direct replenishment type, and the amount of toner in the developing container 32 increases by replenishing toner. The control unit 90 also changes the threshold value for determining the remaining toner amount in accordance with the number of printed images when determining the remaining toner amount in the developing container 32 after toner has been replenished. That is, the image forming apparatus 1 changes the threshold value for determining the remaining toner amount in accordance with the number of printed images not only when determining the Low level or NearOut level but also when determining the Mid level or Full level.

[0103] In this embodiment, the substrate holding member 710 and the substrate 700 are attached to the process unit 20, which includes the transport chamber 36 that stores toner, and the light emitting element 510a and the light receiving element 510b are provided on the substrate 700. Therefore, the relative position of the optical path Q in the transport chamber 36 is constant, and the remaining amount of toner can be detected stably regardless of the positional accuracy of the process unit 20 relative to the printer main body 100.

[0104] Furthermore, the light emitting element 510a and the light receiving element 510b of 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. This allows the light emitting element 510a and the light receiving element 510b to be arranged compactly, and also allows the power supply configuration that supplies power to the light emitting element 510a and the light receiving element 510b to be arranged compactly. This allows the process unit 20 to be made smaller.

[0105] <Second embodiment> Next, a second embodiment of the present invention will be described, but the second embodiment differs from the first embodiment in the method of determining the remaining toner amount. Therefore, the same components as those in the first embodiment will not be illustrated or will be denoted by the same reference numerals in the drawings.

[0106] As shown in FIG. 19 , the control unit 90 in this embodiment includes a CPU 91, a RAM 92, a ROM 93, an I / O interface 94, an A / D converter 95, and an image print count counter 97, similar to the first embodiment. Furthermore, the control unit 90 includes a motor operation rate counter 98 that monitors the rotation state of the motor M1 for the past few minutes since the toner remaining amount sensor 500 of the image forming apparatus 1 started detecting the amount of remaining toner, and calculates the most recent operation rate of the motor M1 (hereinafter referred to as the most recent motor operation rate). That is, the most recent motor operation rate as an operation rate is the operation rate of the motor M1 during the period from the start of detection of the amount of remaining toner (developer amount) by the toner remaining amount sensor 500 until a predetermined time ago. The CPU 91 of the control unit 90 then determines the amount of remaining toner based on the time when the toner remaining amount sensor 500 detected light and the threshold value stored in the table 96. In this embodiment, the threshold value for determining the amount of remaining toner differs depending on the most recent motor operation rate.

[0107] Specifically, when monitoring motor rotation over the past five minutes from the start of toner remaining amount detection, if the motor is in a quiescent state for five minutes or more before toner remaining amount detection begins, the most recent motor operation rate is 0%. On the other hand, if motor M1 rotates continuously for five minutes or more before toner remaining amount detection begins, the most recent motor operation rate is 100%. In this embodiment, if the threshold value is set to 100% when the most recent motor operation rate is 0%, the threshold value is set to 110% when the most recent motor operation rate reaches 100%. Furthermore, as the most recent motor operation rate increases from 0% to 100%, the threshold value is changed from 100% to 110% using linear interpolation according to the most recent motor operation rate.

[0108] The relationship between the most recent motor operating rate and the detection of remaining toner amount is explained below. Figure 20 is a graph showing the relationship between motor rotation time and toner cohesion. As mentioned above, cohesion is an index that indicates how easily toner clumps together. When the toner in the developer container 32 is continuously agitated by the agitator 34, the toner becomes electrically charged and tends to clump together, which tends to increase the cohesion (i.e., toner fluidity tends to decrease). On the other hand, when the agitator 34 is stopped for a certain period of time, the charge on the toner caused by agitation by the agitator 34 gradually decays, the condition in which the toner clumps together is resolved, and the cohesion tends to decrease.

[0109] 20 indicates the period during which the image forming apparatus 1 has been inactive for a certain period of time and then continuously printed images. In other words, in the region SA, the operating rate of the motor M1 is high. When images are continuously printed, the toner cohesion increases, and after a certain number of sheets are printed, the toner cohesion remains constant at a high level.

[0110] Region SB in Figure 20 indicates a period in which the image forming apparatus 1 is idle for a certain period of time after continuously printing images. In other words, in region SB, the operating rate of motor M1 is low. When printing is paused, the toner cohesion gradually decreases, and after a certain period of time, the toner cohesion remains constant at a low level. In this way, the toner cohesion can change depending on the operating status of motor M1. In other words, the toner cohesion changes depending on how often the user uses image forming apparatus 1 and the number of pages printed.

[0111] That is, when a user uses the image forming apparatus 1 to print a small number of sheets at intervals of a certain time or more, the toner cohesion is low and the toner fluidity is high. On the other hand, when a user uses the image forming apparatus 1 continuously, the toner cohesion is high and the toner fluidity is low.

[0112] In this embodiment, the control unit 90 changes the threshold value for determining the remaining toner amount in accordance with the most recent motor operation rate calculated by the motor operation rate counter 98. The table 96 stores multiple combinations of the most recent motor operation rate and the threshold value for determining the remaining toner amount.

[0113] That is, the threshold value for determining the remaining toner amount is set small when the most recent motor operation rate is low, such as when a user prints a small number of sheets at intervals of a certain time or more using image forming apparatus 1. On the other hand, the threshold value for determining the remaining toner amount is set large when the most recent motor operation rate is high, such as when a user uses image forming apparatus 1 continuously.

[0114] For example, as shown in FIG. 18, when the most recent motor operation rate is low, the image forming apparatus 1 employs a Low threshold V1a and a NearOut threshold V1b. On the other hand, when the most recent motor operation rate is high, the image forming apparatus 1 employs a Low threshold V2a and a NearOut threshold V2b. That is, even when detecting the same second amount QT2 of remaining toner, the Low threshold V2a when the most recent motor operation rate is high is greater than the Low threshold V1a when the most recent motor operation rate is low. Also, even when detecting the same first amount QT1 of remaining toner, the NearOut threshold V2b when the most recent motor operation rate is high is greater than the NearOut threshold V1b when the most recent motor operation rate is low. In other words, when the most recent motor operation rate is a first operation rate (e.g., 0%), the threshold for determining whether the remaining toner amount is at the NearOut level is set to the NearOut threshold V1b as the first threshold. Furthermore, when the most recent motor operation rate is a second operation rate (e.g., 100%) that is greater than the first operation rate, the threshold value for determining whether the remaining toner amount is at the NearOut level is set to NearOut threshold V2b as a second threshold value. NearOut threshold V2b is greater than NearOut threshold V1b.

[0115] In this way, by changing the threshold value for determining the remaining toner amount according to the most recent motor operating rate corresponding to the frequency of use of the image forming device 1 by the user, the remaining toner amount in the developing container 32 can be accurately calculated.

[0116] <Other embodiments> In the first embodiment described above, the control unit 90 corrects the threshold value for determining the remaining toner amount in accordance with the number of printed images, but this is not the only possible case. That is, it is also possible to correct the detection time of the remaining toner amount sensor 500 while keeping the remaining toner amount threshold constant.

[0117] Furthermore, in all of the above-described embodiments, the control unit 90 determines the level of the remaining toner in the developing container 32 by comparing the detection time of the remaining toner sensor 500 with a predetermined threshold value, but this is not limiting. For example, the remaining toner sensor 500 may output a signal having a value inversely proportional to the detection time to the control unit 90, and the control unit 90 may compare this value with a threshold value to determine the level of the remaining toner in the developing container 32. In this case, the threshold value is set lower as the degree of toner cohesion increases.

[0118] In addition, in all 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.

[0119] In all 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]

[0120] 1: image forming apparatus / 20: process unit / 21: image carrier (photosensitive drum) / 31: developer carrier (developing roller) / 32: frame (developing container) / 32a: supply port / 34: stirring member / 36: storage section (transport chamber) / 40: supply container (toner pack) / 100: device main body (printer main body) / 400: display section (toner remaining amount panel) / 500: detection unit (toner remaining amount sensor) / 510a: light emitting section (light emitting element) / 510b: light receiving section (light receiving element) / LD: longitudinal direction / M1: drive source (motor) / Tb1: rotation trajectory / V1b: predetermined threshold, first threshold (NearOut threshold) / V1c: first output value (detection time) / V2b: second threshold (NearOut threshold) / V2c: second output value (detection time)

Claims

1. In the image forming apparatus, A device body, an image carrier on which an image is carried; a process unit having a frame constituting a storage section for storing a developer, a developer carrier supported by the frame and configured to supply a developer to an electrostatic latent image formed on the image carrier, thereby developing the electrostatic latent image, and a supply port capable of supplying the developer to the storage section, the process unit being attached to the device main body; a detection unit having 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 container portion, and that outputs an output value corresponding to the amount of developer contained in the container portion; a display unit that is in a first state when the output value output from the detection unit is equal to or smaller than a predetermined threshold, and that is in a second state different from the first state when the output value output from the detection unit is greater than the threshold, the threshold value is set to a first threshold value when the number of printed sheets of the image forming device is a first value, and is set to a second threshold value different from the first threshold value when the number of printed sheets is a second value greater than the first value; An image forming apparatus characterized by:

2. The second threshold is greater than the first threshold.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

3. the process unit has a stirring member that rotates to stir the developer contained in the container; 3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

4. In the image forming apparatus, A device body, an image carrier on which an image is carried; a process unit having a frame constituting a storage section for storing developer, a developer carrier supported by the frame and for supplying developer to an electrostatic latent image formed on the image carrier, thereby developing the electrostatic latent image, an agitating member for rotating to agitate the developer stored in the storage section, and a supply port capable of supplying developer to the storage section, the process unit being attached to the device main body; a drive source that drives the stirring member; a detection unit having 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 container portion, and that outputs an output value corresponding to the amount of developer contained in the container portion; a display unit that is in a first state when the output value output from the detection unit is equal to or smaller than a predetermined threshold, and that is in a second state different from the first state when the output value output from the detection unit is greater than the predetermined threshold, the threshold value is set to a first threshold value when the operation rate of the driving source during a period from when the detection unit starts detecting the developer amount until a predetermined time before that is a first operation rate, and is set to a second threshold value different from the first threshold value when the operation rate is a second operation rate that is greater than the first operation rate; An image forming apparatus characterized by:

5. The second threshold is set to a second threshold greater than the first threshold.

5. The image forming apparatus according to claim 4.

6. the light-emitting unit and the light-receiving unit are arranged side by side in the longitudinal direction of the image carrier, the light emitted from the light-emitting unit passes through the interior of the storage unit within a rotation locus of the stirring member when viewed in the longitudinal direction; 6. The image forming apparatus according to claim 3, wherein the image forming apparatus is a recording medium.

7. the output value is a value corresponding to the time during which the light receiving unit receives the light emitted from the light emitting unit during one rotation of the stirring member.

7. The image forming apparatus according to claim 3, wherein the image forming apparatus is a recording medium.

8. In the image forming apparatus, A device body, an image carrier on which an image is carried; a process unit having a frame constituting a storage section for storing a developer, a developer carrier supported by the frame and configured to supply a developer to an electrostatic latent image formed on the image carrier, thereby developing the electrostatic latent image, and a supply port capable of supplying the developer to the storage section, the process unit being attached to the device main body; a detection unit having 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 container portion, and that outputs an output value corresponding to the amount of developer contained in the container portion; a display unit that is in a first state when the output value output from the detection unit is equal to or smaller than a predetermined threshold, and that is in a second state different from the first state when the output value output from the detection unit is greater than the threshold, the threshold value is set to a first threshold value when the degree of cohesion of the developer contained in the container is a first degree of cohesion, and is set to a second threshold value different from the first threshold value when the degree of cohesion is a second degree of cohesion higher than the first degree of cohesion; An image forming apparatus characterized by:

9. The second threshold is greater than the first threshold.

9. The image forming apparatus according to claim 8,

10. In the image forming apparatus, A device body, an image carrier on which an image is carried; a process unit having a frame constituting a storage section for storing a developer, a developer carrier supported by the frame and configured to supply a developer to an electrostatic latent image formed on the image carrier, thereby developing the electrostatic latent image, and a supply port capable of supplying the developer to the storage section, the process unit being attached to the device main body; a detection unit having 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 container portion, and that outputs an output value corresponding to the amount of developer contained in the container portion; a display unit configured to be able to transition between a first state and a second state different from the first state; the display unit is in the first state when the amount of developer contained in the container is a predetermined amount and the output value is a first output value, and is also in the first state when the amount of developer contained in the container is the predetermined amount and the output value is a second output value different from the first output value. An image forming apparatus characterized by:

11. The display unit is a panel member that lights up continuously in the first state and flashes intermittently in the second state.

11. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

Images