阅读说明：本技术 调色剂输送设备 (Toner conveying apparatus ) 是由 川村知史 田边真人 浜田孝俊 厚祐辅 于 2020-11-12 设计创作，主要内容包括：一种调色剂输送设备,包括：储存部分,其构造为储存由显影设备使用的调色剂；喷射口,其用于从所述储存部分输出调色剂；输送路径单元,其包括接收部分,该接收部分接收从所述喷射口喷射的调色剂,并且构成用于将调色剂输送到所述显影设备的输送路径；泵,其用于将保持在所述储存部分中的调色剂从所述喷射口朝向所述输送路径单元输出；和光学传感器单元,其布置在通过区域中,由所述泵从所述喷射口输出到所述输送路径单元的调色剂经过所述通过区域,并且所述光学传感器单元检测是否存在调色剂。(A toner conveying apparatus comprising: a storage portion configured to store toner used by the developing apparatus; an ejection port for outputting the toner from the storage portion; a conveying path unit including a receiving portion that receives the toner ejected from the ejection port and constitutes a conveying path for conveying the toner to the developing device; a pump for outputting the toner held in the storage portion from the ejection port toward the conveyance path unit; and an optical sensor unit that is disposed in a passage area through which the toner output from the ejection port to the conveyance path unit by the pump passes, and that detects the presence or absence of the toner.)

1. A toner conveying apparatus comprising:

a storage portion configured to store toner used by the developing apparatus;

an ejection port for outputting the toner from the storage portion;

a conveying path unit including a receiving portion that receives the toner ejected from the ejection port and is configured to constitute a conveying path for conveying the toner to the developing device;

a pump configured to output the toner held in the storage portion from the ejection port toward the conveyance path unit; and

an optical sensor unit that is arranged in a passage area through which the toner output from the ejection port to the conveyance path unit by the pump passes, and that is configured to detect the presence of the toner passing through the passage area.

2. The toner conveying apparatus according to claim 1, wherein,

the optical sensor unit includes a light emitting unit that emits light and a light receiving unit that receives light, and an optical path from the light emitting unit to the light receiving unit intersects the passing area.

3. The toner conveying apparatus according to claim 2, wherein,

a pair of light transmitting portions arranged side by side in a direction intersecting a toner ejecting direction is provided in a housing of the conveying path unit, the light emitting unit is arranged at a position corresponding to one light transmitting portion, and the light receiving unit is arranged at a position corresponding to the other light transmitting portion; and is

The light traveling from the light emitting unit to the light receiving unit passes through the one light transmitting portion, the passing region, and the other light transmitting portion in this order.

4. The toner conveying apparatus according to claim 3, wherein,

assuming that, in the passage area, a trajectory of the toner ejected from an upper end of the ejection port is a first trajectory and a trajectory of the toner ejected from a lower end of the ejection port is a second trajectory, the light-transmitting portion is arranged such that, when the light-transmitting portion is projected onto the passage area as viewed from a direction intersecting a toner ejection direction, the light-transmitting portion overlaps an area enclosed in the first trajectory, the second trajectory, a line connecting the upper end and the lower end of the ejection port, and a wall surface of the receiving portion.

5. The toner conveying apparatus according to claim 2, wherein,

assuming that, in the passage area, a trajectory of the toner ejected from an upper end of the ejection port is a first trajectory and a trajectory of the toner ejected from a lower end of the ejection port is a second trajectory, the light receiving unit is arranged such that, when the light receiving unit is projected onto the passage area as viewed from a direction intersecting a toner ejection direction, the light receiving unit overlaps an area enclosed in the first trajectory, the second trajectory, a line connecting the upper and lower ends of the ejection port, and a wall surface of the receiving portion.

6. The toner conveying apparatus according to claim 1, wherein,

the pump is an output device for outputting the toner from the storage portion by imparting kinetic energy to the toner.

7. The toner conveying apparatus according to claim 6, wherein,

the ejection port is formed by a toner passage for outputting the toner from the storage portion, the toner passage guiding the toner output from the storage portion and dropping the toner into the conveyance path unit.

8. The toner conveying apparatus according to claim 7, wherein,

the toner passage includes a substantially horizontal portion that horizontally ejects toner to the conveyance path unit.

9. The toner conveying apparatus according to claim 8, wherein,

the storage portion is arranged above the conveyance path unit; and is

The toner passage is an L-shaped passage including a substantially vertical portion that moves the toner downward from the storage portion and a substantially horizontal portion that connects the substantially vertical portion to the ejection opening, and horizontally ejects the toner from the substantially horizontal portion toward the conveyance path unit.

10. The toner conveying apparatus according to claim 4, wherein,

the first and second trajectories are based on a position of the ejection port and a performance of the pump.

11. The toner conveying apparatus according to claim 6, wherein,

the conveyance path unit includes: an upstream side conveying portion that conveys toner in a horizontal direction; and a downstream side conveying portion connected to the upstream side conveying portion and conveying the toner upward in a vertical direction; and is

The optical sensor unit is disposed in the upstream-side conveying section.

12. An image forming apparatus comprising:

a developing device storing toner;

an image forming unit that forms an image using toner;

a toner conveying device; and

a control unit, wherein

The control unit performs control to replenish toner to the developing device using the toner conveying device when an amount of toner remaining in the developing device falls below a predetermined threshold; and is

The toner conveying apparatus is the toner conveying apparatus according to any one of claims 1 to 11.

Technical Field

The present invention relates to a toner conveying apparatus.

Background

Image forming apparatuses (e.g., printers, copiers, and facsimile machines) that form images by forming toner images using an electrophotographic system are equipped with a developer supply apparatus in a developing apparatus to supply developer consumed by image formation. The developer supply apparatus stores a certain amount of developer taken out of the developer container in a storage unit (hopper), and operates the conveying device to supply the developer from the storage unit to the developing apparatus at a required time.

Patent document 1 (japanese patent No.5762052) proposes a configuration in which toner taken out from a toner bottle as an example of a developer container is held in a hopper of low capacity and conveyed to a developing apparatus at a required time using a screw type conveying mechanism. According to patent document 1, it is necessary to continuously store and maintain a constant amount of toner in a reservoir unit so that a screw type conveying mechanism can stably supply the toner. In this way, the control unit in the image forming apparatus according to patent document 1 detects the surface height of the toner inside the storage unit using the optical sensor, and controls the amount of toner replenished from the toner bottle to the storage unit based on the information.

Disclosure of Invention

In patent document 1, toner is output from a toner bottle serving as a developer container to a storage unit, and then the toner is replenished from the storage unit to a developing apparatus via a conveyance path. The remaining amount of toner is detected using an optical sensor that detects whether toner is present at a predetermined height within the storage unit. Thus, even if there is no toner in the developer container, the system will determine that toner is left as long as toner remains in the storage unit. Therefore, even when the developer container is empty or nearly empty, the system takes a certain time to determine that no toner remains.

In view of the above-described problems, it is an object of the present invention to provide a technique for quickly determining whether a developer container holding toner is empty or almost empty.

The present invention provides a toner conveying apparatus, including:

a storage portion configured to store toner used by the developing apparatus;

an ejection port for outputting the toner from the storage portion;

a conveying path unit including a receiving portion that receives the toner ejected from the ejection port and is configured to constitute a conveying path for conveying the toner to the developing device;

a pump for outputting the toner held in the storage portion from the ejection port toward the conveyance path unit; and

an optical sensor unit that is arranged in a passage area through which the toner output from the ejection port to the conveyance path unit by the pump passes, and that detects the presence or absence of the toner.

Other features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.

Drawings

Fig. 1A and 1B are a plan view and a sectional view, respectively, of an upstream-side conveying section.

Fig. 2 is an overall sectional view of the image forming apparatus.

Fig. 3A to 3D are perspective views of the toner replenishment cartridge as viewed from one end of the toner replenishment cartridge.

Fig. 4A to 4C are diagrams illustrating a mechanism for driving the pump.

Fig. 5 is an exploded perspective view of the toner replenishment cartridge.

Fig. 6 is a perspective view illustrating the overall configuration of the toner conveying apparatus.

Fig. 7A and 7B are a side view and a sectional view of a part of the toner conveying apparatus.

Fig. 8A to 8C are diagrams illustrating toner output from the cartridge.

Fig. 9A and 9B are diagrams illustrating behavior of outputting toner; and is

Fig. 10 is a diagram illustrating the arrangement of the optical sensors with respect to the passage area through which the output toner passes.

Detailed Description

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Note that the scope of the present invention is not intended to be limited to the size, material, shape, relative arrangement, and the like of the constituent elements described in this embodiment, unless otherwise specified.

First embodiment

Integral construction of apparatus

An example of the configuration and image forming operation of the image forming apparatus 1 to which the toner conveying apparatus according to the present invention is applied will be described with reference to the overall sectional view of fig. 2.

The image forming apparatus 1 is an apparatus that forms an image on a recording material 4 using an image forming unit 6(6Y, 6M, 6C, and 6K). The letters Y, M, C and K attached to the reference numerals indicate four colors of yellow, magenta, cyan, and black, respectively. The following description will omit these letters, and when it is not necessary to particularly distinguish colors, the image forming unit is simply referred to as "image forming unit 6".

The image forming unit 6 according to the present embodiment is a process cartridge. The image forming unit 6(6Y, 6M, 6C, and 6K) includes a photosensitive drum 7(7Y, 7M, 7C, and 7K), a charging device 8(8Y, 8M, 8C, and 8K), a developing device 9(9Y, 9M, 9C, and 9K), and a cleaning blade 10(10Y, 10M, 10C, and 10K).

Each photosensitive drum 7 is rotatably supported by a frame member of the corresponding image forming unit 6. The developing device 9 is provided with developing rollers 11(11Y, 11M, 11C, and 11K), and each developing roller 11 is configured to be able to contact and separate from the corresponding photosensitive drum 7. The developing roller 11 is rotationally driven to supply toner (developer) from the developing device 9 to the photosensitive drum 7.

The control unit 60 includes a CPU, a memory (collectively referred to as a volatile memory and a nonvolatile memory), an input/output I/F, a bus, and the like, and performs various processes by communicating with the optical sensor unit 115, the display unit 90, and the like (described later), and an external device such as an external information processing device (a personal computer, a smartphone, and the like). The control unit 60 also receives image data by communicating with the outside, reads out the received image data from the memory, and controls various constituent elements of the imaging apparatus 1 to form an image based on the image data. The control unit 60 is a control unit constituted by a control circuit, an information processing apparatus, and the like. The power supply unit 70 is a high-voltage power supply that supplies power to various constituent elements of the image forming apparatus 1 (e.g., the charging apparatus 8 and the laser scanner unit 12). The drive unit 80 is a drive power source for driving various constituent elements of the image forming apparatus 1, and is a motor for rotationally driving the photosensitive drum 7, the developing roller 11, the upstream-side screw 105, the downstream-side screw 124, the drive coupling 203, and various other types of rollers. The display unit 90 is a display device for providing information to an operator, and any display device, such as a liquid crystal panel, may be used. The display unit 90 may be configured as a touch panel so as to be able to accept operation input.

In the image forming operation, the control unit 60 forms a latent image by causing each charging device 8 to charge the surface of the corresponding photosensitive drum 7 based on image data, and then irradiating the surface of the photosensitive drum with laser light using the laser scanner unit 12. Then, toner is supplied to the photosensitive drum 7 by the developing roller 11, and the latent image on the photosensitive drum surface is visualized as a toner image. The developed toner image is transferred to the intermediate transfer belt 18 at the primary transfer portion 20. Y, M, C and the K toner image are successively transferred to form a four-color toner image on the surface of the intermediate transfer belt 18. The four color toner images are conveyed to the secondary transfer portion 17 by the rotating intermediate transfer belt 18.

Toner replenishment cartridges 13(13Y, 13M, 13C, and 13K), toner conveyance devices 14(14Y, 14M, 14C, and 14K), and toner conveyance drive devices 15(15Y, 15M, 15C, and 15K) are arranged below the image forming units 6(6Y, 6M, 6C, and 6K), respectively. Each toner conveying device 14 functions as a conveying path unit, and is driven by a corresponding toner conveyance driving device 15 as toner is consumed by the image forming unit 6, thereby conveying and replenishing toner from the toner replenishment cartridge 13 to the image forming unit 6.

A cartridge 2 is provided in a lower portion of the image forming apparatus 1, and a recording material 4 of paper or the like is held in the cartridge 2. The cassette feeding portion 3 separates and feeds one recording material 4 at a time by rotation, and the sheet is conveyed downstream by a resist roller 5.

The intermediate transfer unit 16 is disposed above the developing device 9. The intermediate transfer unit 16 includes an intermediate transfer belt 18, a primary transfer roller 19, a tension roller, and the like. The intermediate transfer unit 16 is detachable from the image forming apparatus itself. The intermediate transfer unit 16 is arranged substantially horizontally so that the secondary transfer portion 17 faces the conveyance path of the recording material 4.

The intermediate transfer belt 18 opposed to the photosensitive drum 7 is an endless belt capable of rotating, and is stretched over a plurality of stretching rollers. On the inner surface of the intermediate transfer belt 18, primary transfer rollers 19(19Y, 19M, 19C, and 19K) are arranged opposite to the photosensitive drums 7(7Y, 7M, 7C, and 7K), respectively, and the intermediate transfer belt 18 is located between the primary transfer rollers 19 and the photosensitive drums 7. Primary transfer portions 20(20Y, 20M, 20C, and 20K) are formed between the primary transfer roller 19 and the photosensitive drum 7. At each primary transfer portion 20, a voltage is applied to the primary transfer roller 19, and the toner image is transferred from the photosensitive drum 7 onto the intermediate transfer belt 18.

The intermediate transfer belt 18 is interposed between a secondary transfer opposing roller 31 forming the secondary transfer portion 17 and a secondary transfer roller 21 as a secondary transfer member. The toner image transferred onto the intermediate transfer belt 18 is secondarily transferred onto the recording material 4 at the secondary transfer portion 17. The toner that cannot be completely transferred onto the recording material 4 during the secondary transfer and thus remains on the intermediate transfer belt 18 is removed by the cleaning unit 22. The toner removed by the cleaning unit 22 is conveyed to the toner collection container 24 via the collected toner conveying unit 23 and accumulated in the toner collection container 24.

After undergoing the secondary transfer of the toner image, the recording material 4 is conveyed further downstream (upward in fig. 2), and is compressed and heated by the heating unit 25a and the pressing roller 25b of the fixing device 25. This melts the toner and fixes the toner image on the recording material 4. The recording material 4 is then conveyed to a discharge roller pair 26 and discharged to a discharge tray 27. The aforementioned series of operations are image forming operations for forming an image on the surface of the recording material.

Configuration for toner replenishment

Next, a toner replenishment cartridge 13 and a configuration for conveying toner, which are characteristic configurations of the present embodiment, will be described with reference to fig. 3A to 4C. Fig. 3A is a perspective view of the toner replenishment cartridges 13Y, 13M, and 13C. In fig. 3A to 3D, the direction indicated by the arrow B is the insertion direction in which the toner replenishment cartridge 13 is mounted to the image forming apparatus main body. In contrast, the direction opposite to the arrow B is the direction in which the toner replenishment cartridge 13 is taken out from the image forming apparatus main body. Fig. 3B is a perspective view of a state where the side cover 224 is removed from the cartridge shown in fig. 3A. Fig. 3C is a perspective view of the toner replenishment cartridge 13K, and fig. 3D is a perspective view of a state where the side cover 224 has been removed from the cartridge shown in fig. 3C.

Fig. 4A to 4C are diagrams illustrating a configuration of a cam for outputting toner, and illustrate one end of the toner replenishment cartridge. Fig. 4A is a diagram showing the configuration of the cam gear 220, the link mechanism 221, and the pump 223. Fig. 4B is a cross-sectional view of the configuration shown in fig. 4A. Fig. 4C is a developed view of the cam groove 220a in the cam gear 220.

As shown in fig. 3A to 3D, the toner replenishment cartridge 13 includes a replenishment frame member 201 having a substantially rectangular shape with a longer direction and a shorter direction. The supplementary frame member 201 can contain toner therein. The drive coupling 203, the cam gear 220, the link mechanism 221, the pump 223, and the screw gear 226 are arranged on the downstream side of the toner replenishment cartridge 13 in the mounting direction (the direction indicated by the arrow B), and are covered by the side cover 224. A discharge baffle 207 provided with a discharge port 208 is provided on the bottom surface side (lower side in the normal use orientation). The gear portion of the cam gear 220 meshes with the screw gear 226, and the screw gear 226 receives a rotational driving force from the cam gear 220. Thus, the screw gear 226 rotates together with the cam gear 220.

The drive coupling 203 is provided to transmit a driving force to the cam gear 220 and the toner replenishing screw 209 located in the replenishing frame member 201. When the toner replenishment cartridge 13 is mounted in the image forming apparatus 1, the drive coupling 203 is engaged with a main body side drive coupling (not shown). As a result, the driving force from the driving unit 80 is transmitted to the toner replenishing cartridge side.

As shown in fig. 4A to 4C, the cam gear 220 is provided with a cam groove 220a, and a cam protrusion 221a of the link mechanism 221 is engaged with the cam groove 220 a. Both ends of the link mechanism 221 are guided by the guides 224a and 224b of the side cover 224 and are supported to be capable of reciprocating relative to the side cover 224 in the direction indicated by the arrow C (see fig. 5). As shown in fig. 5, the guides 224a and 224b correspond to the protruding portions of the side cover 224. A space is formed in the protruding portion, and the end portions 221a and 221b of the link mechanism 221 are disposed in the space. Therefore, the position of the link mechanism 221 is restricted by the guides 224a and 224b, so that the link mechanism 221 can move in the direction indicated by the arrow C, but the rotational movement of the link mechanism 221 about the axis 500 is restricted. The cam groove 220a is provided with a crest portion 220B inclined to the downstream side in the mounting direction (the direction of arrow B) and a trough portion 220c inclined to the upstream side in the mounting direction (the direction of arrow B). According to this structure, when the cam gear 220 rotates, the cam protrusion 221a fitted into the cam groove 220a alternately passes the crest portion 220b and the trough portion 220 c. As a result, the rotational motion of the gear is converted into the back-and-forth motion of the link mechanism, which causes the link mechanism 221 to move back and forth in the mounting direction (the direction indicated by the arrow B).

Here, one end of the pump 223 in the mounting direction is connected to the link mechanism 221 through a coupling portion 223 b. The other end of the pump 223 in the mounting direction is fixed to the supplementary frame member 201 by a connecting portion 223 c. In addition, the internal space 223d of the pump 223 communicates with the internal space of the supplementary frame member 201 (i.e., the toner storage chamber 201a that serves as a storage portion and stores toner) via the connection portion 223 c.

According to this configuration, the connection portion 223c of the pump 223 is fixed to the supplementary frame member 201, and therefore, when the coupling portion 223B of the pump 223 moves back and forth in conjunction with the link mechanism 221, the bellows portion 223a of the pump 223 expands and contracts (see fig. 8A and 8B). This expansion and contraction causes the volume of the internal space 223d of the pump 223 to change, and as a result, the internal pressure of the toner storage chamber 201a communicating with the internal space 223d fluctuates. This imparts kinetic energy to the toner, and the toner is discharged from the discharge port 208. Note that the output device is not limited to a pump, and any device may be used as long as it can output toner by imparting kinetic energy.

Fig. 6 shows the overall configuration of the toner conveying apparatus 14 provided in the image forming apparatus. Note that fig. 6 omits a partial shape of the toner conveying device 14 to illustrate its internal configuration. The configuration of the toner conveying apparatus 14 is roughly divided into an upstream-side conveying portion 100 and a downstream-side conveying portion 120.

A feed port 101 is formed in an upper surface of the upstream side conveying section 100. The toner supplied from the toner replenishment cartridge 13 passes through the feed port 101, and is supplied to the storage container 108 in the upstream side conveying portion 100. The upstream-side conveying section 100 includes an upstream-side screw 105, and the upstream-side screw 105 is arranged to be covered by a storage container 108. The toner falling from the feed port 101 is distributed over the entire area where the upstream-side screw 105 is arranged. Then, the toner is conveyed by the upstream-side screw 105 in a direction toward the downstream-side conveying portion 120, and the upstream-side screw 105 is rotationally driven by the upstream-side drive gear 103.

The downstream-side conveying section 120 includes a downstream-side wall surface 123. The downstream side screw 124 is disposed in such a manner as to be covered with the downstream side wall surface 123. The most upstream side portion (lower portion in fig. 6) of the downstream-side conveying portion 120 is connected to the most downstream side portion of the upstream-side conveying portion 100, and the toner conveyed by the upstream-side conveying portion 100 is conveyed to the downstream-side screw 124. The downstream-side screw 124 is rotationally driven by the downstream-side drive gear 122, and conveys the toner in a direction opposite to the direction of gravity. The toner conveyed by the downstream-side screw 124 is supplied to the developing device 9 through the main body discharge port 121.

Detailed description of the upstream-side conveying unit 100

Next, the toner conveying device 14 will be described in detail with reference to fig. 1A, 1B, 7A, and 7B. Fig. 1A is a diagram showing the upstream-side conveying section 100 from above. FIG. 1B is a cross-sectional view taken along line A1-A1 in FIG. 1A. Fig. 7A is a diagram showing the upstream-side conveying section 100 from the side. Fig. 7B is a sectional view taken along line a2-a2 in fig. 7A.

As shown in fig. 1B, the configuration of the upstream side conveying portion 100 can be roughly divided into a storage container 108 serving as a toner receiving portion and a storage container cover 109. The storage container 108 and the storage container cover 109 are substantially constituted by a wall surface formed by at least one resin frame. The feed port seal 102 is fixed to an upper portion of the feed port 101 formed in the storage container cover 109, and the feed port seal 102 seals the periphery of the feed port 101 to prevent toner scattering. An L-shaped passage 106 serving as a toner passage is attached to the bottom of the feed port 101. The L-shaped passage 106 includes a substantially horizontal portion connecting the substantially vertical portion to the injection port 106a and a substantially vertical portion connected to the feed port 101. With this configuration, the toner that has been replenished from the feed port 101 is ejected toward the space S that is located in the extension of the substantially horizontal portion of the L-shaped passage 106. In this way, the L-shaped passage 106 forms the injection port 106 a. The ejected toner falls and accumulates at the bottom of the storage container 108 while passing through the passing area.

As shown in fig. 7B, a light-transmitting member 107 serving as a pair of light-transmitting portions is attached to a side wall of the storage container 108 in the vicinity of the ejection port 106a in the L-shaped passage 106. In the present embodiment, a pair of light-transmitting members 107 are provided on both side surfaces of a storage container 108 serving as a housing. The direction connecting the pair of light-transmitting members 107 intersects the direction of ejecting the toner from the ejection port 106a in the L-shaped passage 106 toward the space S in the toner passing region.

The optical sensor unit 115 includes a light emitting substrate 115a and a light receiving substrate 115b, the light emitting substrate 115a serving as a light emitting unit and including a light emitting element and a driving circuit thereof, and the light receiving substrate 115b serving as a light receiving unit and including a light receiving unit and a driving circuit thereof. The light emitting substrate 115a of the optical sensor unit 115 is disposed outside one of the pair of light transmitting members 107. The light receiving substrate 115b is disposed outside the other light transmitting member 107. In other words, the light emitting substrate 115a, one of the light transmitting members, the toner passing region, the other of the light transmitting members, and the light receiving substrate 115b are disposed in this order in a direction connecting the pair of light transmitting members 107. According to this structure, the light path P from the light emitting substrate 115a to the light receiving substrate 115b intersects the toner passing region.

As a result, the toner can be detected by the optical sensor unit 115, which makes it possible to determine whether the toner is present. In other words, if there is no toner in the light path P through which the light emitted from the light emitting substrate 115a under the control of the control unit 60 passes to the light receiving substrate 115b via the pair of light transmitting members 107, the control unit 60 can determine that there is no toner since the light receiving substrate 115b has detected the light. On the other hand, if the light is blocked by the toner and the light receiving substrate 115b cannot detect the light under a predetermined condition, the control unit 60 may determine that the toner is present. Note that the control unit 60 may perform determination according to the light intensity of the light reaching the light receiving substrate 115 b.

For example, a Light Emitting Diode (LED) emitting light such as infrared light may be used as the light emitting element included in the light emitting substrate 115 a. However, the wavelength range of the light is not limited thereto, and the light may be visible light instead. Another light source member such as a semiconductor Laser (LD) may be used instead of the LED. A known light receiving substrate (e.g., a photosensor) may be used as the light receiving unit included in the light receiving substrate 115 b. Any other optical sensor may be used as long as the sensor can determine whether an object exists on the optical path using light.

A material (e.g., acrylic resin) that is transmissive with respect to the wavelength range of light emitted from the light emitting substrate 115a may be preferably used as the light transmitting member 107. The light-transmitting member 107 may have any shape and may be provided at any position as long as an optical path can be formed in a passing area through which the toner passes when it falls, and may be non-circular. In addition, in order to define the optical path, an optical member such as a rod lens made of acrylic resin may be used as the light-transmitting member 107, or the optical member may be disposed near the light-transmitting member 107.

The intensity of light received by the light receiving substrate 115b when the light emitting substrate 115a emits light at a predetermined intensity is stored in advance in the memory of the control unit 60. Then, the presence or absence of toner in the passing area is determined by comparing the light intensity of light received by the light receiving substrate 115b with the stored light intensity at the time of light emission. In other words, when the light receiving substrate 115b has received light having at least a predetermined optical intensity, the control unit 60 determines that there is no toner or almost no toner, and performs a predetermined process. Alternatively, time information on the time when the light-receiving substrate 115b receives light when the light-emitting substrate 115a emits light at a predetermined light intensity is stored in advance in the memory of the control unit 60. In this case, whether or not the toner is present in the passing area is determined according to the length of time that the light receiving substrate 115b receives light within a predetermined period of time exceeding a threshold time. In other words, when the light receiving substrate 115b has received light for at least a predetermined time, the control unit 60 determines that there is no toner or almost no toner, and performs a predetermined process.

Here, the predetermined processing executed by the control unit 60 when it is determined that there is no toner or almost no toner includes, for example, displaying a message prompting replacement of the toner replenishment cartridge in the display unit 90.

As shown in fig. 7B, in the present embodiment, the ejection opening 106a in the L-shaped passage 106 has a square cross-sectional shape with one side La of 3.5 mm. Further, as shown in FIG. 1B, the L-shaped channel 106 has a vertical channel length Lb of 7.6mm and a horizontal channel length Lc of 12.5 mm. Although the cross-sectional shape of the L-shaped channel 106 is described as square in the present embodiment, another shape, such as rectangular or circular, may alternatively be used. The vertical and horizontal channel lengths may vary depending on the size, shape, etc. of the cross-sectional shape. It is desirable to set the cross-sectional shape to an optimum shape according to the size and arrangement of the light-transmitting member 107, the detection range of the optical sensor, and the like.

Remaining amount detection method during execution of operation at toner replenishment

Next, a method of detecting the amount of remaining toner during the operation of replenishing toner from the toner replenishment cartridge 13 will be described with reference to fig. 8A to 8C and 9A to 9B. Fig. 8A is a diagram showing the inside of the toner replenishment cartridge 13 from above. Fig. 8B and 8C are sectional views taken along line A3-A3, and illustrate toner T. Fig. 8B shows pump 223 in an expanded state and fig. 8C shows pump 223 in a contracted state. Similar to fig. 1B, fig. 9A and 9B are cross-sectional views taken along line a1-a1 in fig. 1A. Fig. 9A corresponds to fig. 8B, and fig. 9B corresponds to fig. 8C.

As described above, when the amount of toner remaining in the developing device decreases or decreases from a predetermined amount, the control unit 60 performs control to replenish toner from the toner replenishment cartridge 13 to the developing device 9. The control unit 60 obtains the amount of toner remaining in the developing device 9 by a given method such as optical detection or weight-based detection, and sends a replenishment signal to the toner conveying device side when the remaining amount reaches zero or falls below a predetermined threshold. As shown in fig. 8B and 8C, when a replenishment signal is received on the toner conveying apparatus side, the cam gear 220 arranged coaxially with the drive coupling 203 (not shown) and the pump 223 rotates, causing the pump 223 to repeatedly expand and contract between the expanded state (fig. 8B) and the contracted state (fig. 8C).

As shown in fig. 8B, the internal space 223d of the pump 223 and the toner storage chamber 201a communicate via the communication port 201B. Therefore, when the pump 223 contracts as shown in fig. 8C, the internal pressure of the toner storage chamber 201a rises, and the toner T that has been conveyed into the toner storage chamber 201a by the toner replenishing screw 209 can be discharged from the discharge port 208. As shown in fig. 8B and 8C, in the present embodiment, the pump diameter Φ is 42mm, the length L1 in the unloaded state (expanded state) is 20.1mm, the length L2 in the contracted state is 8.1mm, and the expansion/contraction stroke is 12 mm. One expansion/contraction period T of the pump is 0.38 seconds. With the shape and design specifications of such a pump, the toner T can be discharged into the toner storage chamber 201a via the L-shaped passage 106 of the upstream-side conveying portion 100.

Next, the supply of toner in the upstream side conveying portion 100 will be described with reference to fig. 9A and 9B. Fig. 9A shows a state where toner is not replenished from the toner replenishing cartridge 13, and fig. 9B shows a state where toner is being replenished from the toner replenishing cartridge 13.

As shown in fig. 9A, when the toner is not replenished, a set amount of toner is held in the storage container 108. The toner surface in the storage container 108 at this time is referred to as "toner surface Z". The toner surface Z is defined by the structure of the inner surface of the storage container 108, the configuration and performance of the upstream side screw 105, and the like. In the state shown in fig. 9A, the light transmitting member 107 and the toner surface Z do not overlap when viewed from the angle shown in the figure.

When the toner starts to be replenished, the state is shifted to the state shown in fig. 9B, in which the toner in the toner storage chamber 201a is discharged into the storage container 108 through the L-shaped passage 106. Here, a trajectory along which the toner discharged from the ejection opening 106a in the L-shaped passage 106 falls on the toner surface Z in the storage container 108 will be referred to as "toner falling trajectory K". The upper and lower ends of the toner falling trajectory K in the vertical direction are indicated by broken lines in fig. 9B. Assuming that the trajectory of the toner ejected from the upper end is a first trajectory and the trajectory of the toner ejected from the lower end is a second trajectory, the range enclosed by the first trajectory, the second trajectory, the ejection port 106a, and the toner surface Z corresponds to a passing area through which the toner passes when it falls after being ejected. The light-transmitting member 107 is arranged to project onto at least one of the first track and the second track when viewed from the angle shown in the figure. Preferably, the light-transmissive member 107 is arranged to project onto both the first track and the second track.

Preferably, the pair of light transmitting portions are arranged to overlap a region enclosed within (i) the first locus, (ii) the second locus, (iii) a line connecting an upper end and a lower end of the ejection opening, and (iv) a wall surface of the receiving portion when projected onto the passing region as viewed from a direction intersecting the toner ejection direction. This ensures that the optical path of the optical sensor overlaps the toner passing area.

From a different point of view, it is preferable that the light receiving unit is arranged to overlap a region enclosed within (i) the first trajectory, (ii) the second trajectory, (iii) a line connecting upper and lower ends of the ejection opening, and (iv) a wall surface of the receiving portion when projected onto the passing region as viewed from a direction intersecting the toner ejection direction. This also ensures that the optical path of the optical sensor overlaps the toner passing area.

With this configuration, the optical sensor can detect the presence or absence of the toner discharged from the ejection port 106a via the light transmitting member 107. If the toner is not discharged from the ejection opening 106a despite the replenishing operation, the control unit 60 may determine that the toner in the toner replenishing cartridge 13 has run out. This makes it possible to quickly determine that there is no toner remaining in the developer container. Note that if the light-transmitting member 107 has a function for focusing light and an optical member that reflects the focused light to a given position is also provided, the position of the light-receiving unit of the light-emitting substrate 115a when viewed from the direction intersecting the toner ejection direction does not need to overlap the toner drop trajectory. On the other hand, if the light-transmitting member 107 does not have such a function, at least a part of the light-receiving unit of the light-emitting substrate 115a must overlap with the toner falling trajectory when viewed from the direction intersecting the toner ejection direction.

A condition for determining whether toner exists using the optical sensor will be considered with reference to fig. 10. Here, "toner-free" refers to a state where no toner or almost no toner is discharged from the toner replenishing cartridge. Alternatively, "toner-free" means a state in which the toner replenishing cartridge is empty or almost empty. Fig. 10 is a sectional view showing a part of the storage container 108 in an enlarged manner, and is a view for considering a path (trajectory) that the discharged toner may follow when it falls and an arrangement condition that enables the optical sensor to detect the toner when it falls. As described above, by arranging the light transmitting member 107 and the light receiving unit of the light emitting substrate 115a to overlap the passage area defined by the upper and lower ends of the toner falling trajectory K when viewed from the angle shown in the drawing, the light path intersects the toner passage area. Note, however, that the light-transmitting member 107 and the light-receiving unit of the light-emitting substrate 115a do not necessarily have to be entirely within the passage area. It is sufficient that the light receiving unit of the light emitting substrate 115a is disposed to at least partially overlap with the passing area as long as light passing through the light transmitting member 107 can be detected by the optical sensor unit 115.

The present embodiment assumes that the toner passes through the horizontal passage of the L-shaped passage 106 and is then ejected horizontally from the ejection port 106 a. Let T be₁Denotes toner, T, ejected from the lower end of the ejection opening 106a₂Denotes toner, T, ejected from the upper end of the ejection opening 106a_{1_0}(x₁，z₁) Indicating toner T at the time of ejection₁Coordinate of (2), T_{2_0}(x₁，z₂) Indicating toner T at the time of ejection₂The coordinates of (a). It is also assumed that the toner ejection direction is a positive direction along the x-axis, and the toner falling direction (downward in the vertical direction) is a positive direction along the z-axis.

Assume that the initial velocity of the toner is V₀m/s, the toner is Vx-V in the horizontal direction₀Moves and falls freely in the vertical direction at a speed Vz gt. This is achieved byThe displacement amount from the initial coordinate t seconds after the injection is (V)₀t，(1/2)gt²) And the toner falling trajectory is given as z ═ g/2V₀ ²)·x². Thus, the toner T T seconds after ejection₁Has a coordinate of T_{1_t}(x₁+V₀t，z₁+1/2·gt²) And toner T₂Has a coordinate of T_{2_t}(x₁+V₀t，z₂+1/2·gt²)。

For the toner ejected from the ejection opening 106a, by assuming V₀The initial velocity of the uniform linear motion in m/s and the free fall motion define the range of the fall trajectory. This is based on the assumption that most of the toner ejected from the ejection opening 106a is ejected as pellets adjacent to each other, so that the influence of air resistance can be ignored.

Having T at the time of injection_{1_0}(x₁，z₁) Toner T of coordinates of₁May be defined by the following equation. Toner T₁The coordinates of (a) are expressed as follows:

X＝x₁+V₀t...(1)，

Z＝(z₁+1/2·gt²)…(2)

using equations (1) and (2) to eliminate t, the following equation (3) can be obtained.

Z＝z₁+1/2·g((X-x₁)/V₀)²…(3)

By appropriately substituting the value of X in this equation (3), the value of Z coordinate at an arbitrary X coordinate of the toner ejected from the lower end of the ejection opening 106a can be obtained. In other words, this formula (3) represents the moving locus of the toner ejected from the lower end of the ejection opening 106a in fig. 10 as a function of the X axis.

Likewise, having T at injection may also be defined by the following equation_{2_0}(x₁，z₂) Toner T of coordinates of₂The movement locus of (2). Toner T₂The coordinates of (a) are expressed as follows:

X＝x₁+V₀t…(4)，

Z＝(z₂+1/2·gt²)…(5)

using equations (4) and (5) to eliminate t, the following equation (6) can be obtained.

Z＝z₂+1/2·g((X-x₁)/V₀)²…(6)

By appropriately substituting the value of X in this equation (6), the value of Z coordinate at an arbitrary X coordinate of the toner ejected from the upper end of the ejection opening 106a can be obtained. In other words, this formula (6) represents the moving locus of the toner ejected from the upper end of the ejection opening 106a in fig. 10 as a function of the X axis.

In this way, the above-described equations (3) and (6) can define the toner passage area (passage locus) ejected from the ejection opening 106 a. In the configuration according to the present embodiment, the light-transmitting member 107 is disposed such that the optical path of the optical sensor overlaps with the toner passing region.

In this way, by ensuring that the light transmitting member 107 and the light receiving unit of the light emitting substrate 115a fall at least partially within this range, the light path P can be made to intersect the toner passing region. Preferably, as in the example shown here, the light-transmitting member 107 is arranged to cover the upper and lower ends of the toner passing region. By so doing, the optical sensor reliably detects any toner discharge, which improves the accuracy of detection.

Here, the initial velocity V₀Is a predetermined value determined by the toner characteristics (e.g., material and shape), the performance of the pump 223 (e.g., the cross-sectional area of the pump 223 and the stroke during the return and return movement), and the position and size of the ejection port 106 a. In other words, the above-described first and second trajectories are also determined by the toner characteristics (e.g., material and shape), the performance of the pump 223 (e.g., the cross-sectional area of the pump 223 and the stroke during the return and return movement), and the position and size of the ejection port 106 a. In this way, the toner passing area after ejection can be calculated in advance using the above formula. Therefore, arranging the light-transmitting member 107 in such a manner as to overlap the toner passing region when projecting the light-transmitting member 107, it is possible to reliably detect whether there is toner remaining.

The shape of the passage through which the toner output from the pump is ejected into the storage container 108 is not limited to the L shape. Further, the method for ejecting the toner is not limited to the horizontal ejection. For example, the toner may fall freely, or may be ejected at an angle. Even in this case, the light-transmitting member 107 and the optical sensor may be arranged according to a trajectory that the toner is expected to follow when falling.

As described above, according to the present invention, since the transparent member is provided in the vicinity of the path through which the toner passes, the discharged toner can be directly detected. This makes it possible to quickly determine that the toner in the toner replenishment cartridge has run out or is close to running out, and thus usability can be improved.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.