JP2001209245A - Developing device and image forming device - Google Patents

Abstract

(57) [Summary] (with correction) [PROBLEMS] To provide a developing device having a configuration capable of always accurately determining the remaining amount of a developer without increasing costs and increasing the size of the device, and a developing device having the same. Obtain the used image forming apparatus. A developing device for visualizing a latent image on a latent image carrier has remaining amount detecting means for supplying the latent image carrier, and the remaining amount detecting means.
Is characterized in that the number of remaining amount detections is accumulated, and the remaining amount of the developer is determined based on the accumulated number of times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device and an image forming apparatus such as a copying machine or a printer, and more particularly, to a developer remaining amount warning device used for visible image processing.

[0002]

2. Description of the Related Art In general, a photoconductor constituting a latent image carrier is used in an image forming apparatus such as a copying machine or a printer. In an image forming apparatus, for example, in the case of using an electrophotographic process, light writing is performed using a laser beam or the like in a state where a photoconductor is uniformly charged, and a latent image corresponding to a document is formed, and then a developer is used. After the latent image is processed with a visible image, the visible image is transferred to a transfer paper or the like to obtain an image.

In recent years, color image forming apparatuses for forming images of not only a single color but also a plurality of colors including a full color have been proposed and put into practical use. In a color image forming apparatus, a latent image is formed on a photoreceptor by reflected light obtained by performing color separation of reflected light from a document, and in a printer, irradiation images corresponding to color information form latent images. The visible image is processed with a developer of a color that is complementary to the color-separated reflected light or irradiation light, and the process of primary transferring the visible image to the intermediate transfer member is repeated. The corresponding visible images are collectively transferred to a transfer paper or the like by a secondary transfer process.

As one of the structures of a developing device used for visible image processing in a color image forming apparatus, a developing unit containing developers of different colors at regular intervals along a circumferential direction of a rotating body is arranged. There is a configuration in which each developing unit faces the photoconductor by intermittently rotating the rotator to perform visible image processing of a latent image by using developers of different colors. The developing unit may use a one-component developer composed of only a magnetic or non-magnetic toner. In this case, the one-component developer supported on a developing sleeve disposed opposite to the photoconductor is used. The developer is carried in a thin layer by a blade or the like.

In a developing device provided in a color image forming apparatus, an image is formed by supplying a developer with one of developing units arranged side by side in a circumferential direction to face a photosensitive member. When image formation is not performed, that is, during non-image formation, the developing unit is not opposed to the photoconductor, thereby preventing the photoconductor from being stained. For this reason, the developing device is maintained in a standby state in which the developing unit does not face the photoconductor until image formation is restarted during non-image formation. In the developing device,
It is necessary to prevent the occurrence of predetermined image density and color unevenness as the contained developer is consumed for visible image processing. For this reason, in the developing device, a configuration is adopted in which when the developer is almost exhausted, the user is alerted of the condition and is prompted to supply the developer.

Conventionally, as a configuration for detecting the remaining amount of the developer in order to warn that the developer runs out, for example, those disclosed in JP-A-7-160105 and JP-A-7-181772 are known. . The configurations disclosed in these publications include a light-emitting and light-receiving element that is arranged outside the developing device and has an optical path configured to traverse the developing tank of the developing device, and the remaining developer in the developing device is provided. The transmission state of light from the light-emitting element to the light-receiving element according to the amount, in other words, the change in the amount of light is used, and when the amount of light from the light-emitting element to the light-receiving element is less than a predetermined value. Indicates that there is a sufficient amount of developer remaining, and that the amount of light is
In the case of so-called transmission or a state equivalent thereto, the remaining amount of the developer is small, and it is determined that the above-described problem occurs during visible image processing.

[0007]

However, when the optical remaining amount detecting structure having the above structure is used, it may not be possible to accurately determine the remaining amount of the developer. That is, if the optical axis from the light emitting element to the light receiving element is shifted or one of the elements does not function properly, the light from the light receiving element is notwithstanding the small amount of the developer remaining in the developing device. In some cases, the output of the photoelectric conversion signal does not correspond to the state, and the output may be the same as when the remaining amount of the developer is sufficient. As a result, when the determination of the remaining amount of the developer in the developing device becomes abnormal or the determination of the remaining amount is delayed, a problem such as occurrence of an abnormal image or inadvertent shutdown of the developing device occurs. There is a risk of doing so.

On the other hand, when the remaining amount of the developer becomes small, it is necessary to replenish the developer. One of the constitutions for this is to attach a developer cartridge containing the replenishment developer to the developing device. There is a configuration provided detachably. In such a configuration, by detecting that the cartridge has been replaced with a new cartridge, correction of development characteristics and detection of the remaining amount of the developer are started for the newly replenished developer. Therefore, a configuration for detecting replacement of the cartridge is required. However, providing such a configuration results in an increase in installation space and an increase in the number of assembling steps. Cause you to

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the conventional developing apparatus and the image forming apparatus using the same, it is an object of the present invention to always accurately determine the remaining amount of the developer without increasing the cost and the size of the apparatus. It is an object of the present invention to provide a developing device having a configuration capable of performing the image forming operation and an image forming apparatus using the same.

[0010]

According to the first aspect of the present invention,
In a developing device for visualizing the latent image on the latent image carrier, the developing device has a remaining amount detecting means of the developer supplied to the latent image carrier,
The remaining amount detection means is characterized in that it has a configuration in which the number of remaining amount detections is accumulated, and the remaining amount of the developer is determined based on the accumulated number of times.

According to a third aspect of the present invention, the remaining amount detecting means detects the remaining amount of the developer every time visible image processing is performed on the latent image carrier. .

According to a fourth aspect of the present invention, the remaining amount detecting means detects the remaining amount of the developer every time the developing characteristics are corrected each time a predetermined number of images are formed.

According to a fifth aspect of the present invention, when the control section determines that there is no remaining amount of the developer, it is possible to determine from the output signal from the optical sensor that a new developer has been replenished. Features.

According to a sixth aspect of the present invention, when the output signal from the optical sensor is not obtained continuously for a certain number of times or more in the control section, it is determined that a new developer has been replenished. .

According to a seventh aspect of the present invention, there is provided an image forming apparatus provided with a developing device capable of supplying a plurality of colors of developers to the latent image carrier, wherein the developing devices are juxtaposed in a circumferential direction. The developing unit is a rotatable developing device that is rotatable. The developing unit is provided with a detachable developer replenishing member containing the developer, and a developer remaining amount in the developer replenishing member. Detecting means is provided, and the remaining amount detecting means accumulates the number of remaining amount detections, and determines that the remaining amount of the developer is exhausted according to the accumulated number of times.

According to an eighth aspect of the present invention, the remaining amount detecting means is provided with a pair of a space in which a developer is interposed within a developer replenishing member used for replenishing the developer. A light transmitting unit, an optical sensor disposed outside the developing developer replenishing member and opposed to the light transmitting unit, the optical sensor is connected to an input side, and an alarm unit is connected to an output side; A control unit, which is configured to warn that developer replenishment becomes impossible when the cumulative number of remaining amount detections reaches a predetermined number, separately from the determination of the light transmission state using the optical sensor. According to a ninth aspect of the present invention, when the control section determines that there is no remaining amount of the developer, the control section determines that the developer replenishing member is newly replaced by an output signal from the optical sensor. Features that it is possible It is.

According to a tenth aspect of the present invention, after the replacement of the developer replenishing member, the optical sensor determines that the replacement of the developer replenishment member has been completed if the optical sensor does not transmit light a predetermined number of times. .

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram for explaining a main configuration of a color image forming apparatus, which is one of the image forming apparatuses using the developing device according to the present embodiment. In FIG. 1, a color image forming apparatus 1 includes a photosensitive member 2 as a latent image carrier in a housing. The photoreceptor 2 has a belt shape (hereinafter, referred to as a photoreceptor belt) wound around a pair of pulleys 2A, 2B.
Is rotated in the clockwise direction indicated by the arrow and moves in the direction indicated by the arrow. In FIG. 2, a roller 2C disposed inside the photosensitive belt 2 is a tension roller. Around the photoreceptor belt 2, a charging device 3, an optical writing device 4, a developing device 5, a transfer device 6, and a cleaning device 7 for performing electrophotography along the moving direction.
Are arranged respectively.

As will be described later, the developing device 5 has a structure in which developing units accommodating developers for a plurality of colors are arranged along the circumferential direction, and each developing unit is sequentially The developer is supplied to face the belt 2.

The transfer device 6 is wound around a pair of rollers 6A and 6B provided in a process cartridge 30 which can be inserted into and removed from the apparatus main body, and moves in the same direction at a position facing the photosensitive belt 2. Transfer belt 6C,
A bias device 6D for setting a transfer bias is arranged at a position facing the photoreceptor belt 2. Transfer belt 6C
Is provided with a cleaning device 6E provided with a cleaning blade that can be brought into contact with the non-transfer process. The developer removed from the transfer belt 6C is transported by a screw auger or the like, and the transfer member 6F is connected to the transfer member 6F. The photosensitive belt 2 is transported via a member (not shown) to a collection unit 7A disposed in the cleaning device 7 for the photosensitive belt 2.

The cleaning device 7 for the photosensitive belt 2 includes:
A cleaning member capable of contacting the photosensitive belt 2;
The developer removed from the photosensitive belt 2 is transferred to the transfer belt 6.
The developer is introduced into the collection section 7A together with the developer collected from the cleaning device 6E of C. Collection unit 7
A is a process cartridge 3 in which a transfer belt 6C, a photosensitive belt 2, a charging device 3, and a cleaning device 6E for the transfer belt 6C are collectively arranged.
When the developer is filled with the waste developer, the developer is taken out of the process cartridge 30 and the developer can be discarded. A part of the shape of the process cartridge 30 forms a guide surface of a recording medium fed from the sheet feeding device 8.

Further, the transfer device 6 serving as an intermediate transfer portion is provided with a toner adhesion sensor 31 for detecting the amount of developer attached to the transfer belt 6C, and the charge characteristics of the developer, which affect the image density, and the like. The amount of the applied developer is detected as data for process control for correcting development characteristics such as a development bias.
As the developer adhesion sensor 31, an infrared light emitting diode is used for the light emitting unit and a photodiode is used for the diffuse reflection light receiving unit, and outputs a voltage according to the amount of received light. In the vicinity of the transfer device 6, a batch transfer device 9 is disposed on the roller 6A side so as to face the expansion surface of the transfer belt 6C opposite to the surface facing the photosensitive belt 2 among the expansion surfaces. The batch transfer device 9 includes a bias device that batch-transfers a full-color image that is superimposedly transferred onto the transfer belt 6C onto a recording medium such as a transfer sheet fed from the sheet feeding device 8.

The paper feeding device 8 includes a paper feeding cassette 8A for accommodating a recording medium such as transfer paper, a feeding roller 8B for feeding out the recording medium from the paper feeding cassette 8A, a conveying roller 8B1, and a registration roller 8B2. Have. In this embodiment, a part of the housing of the color image forming apparatus 1 (for convenience, indicated by reference numeral 1A) is provided as an openable and closable cover, and a manual paper feed tray 1B is provided therein. A conveyance path switching claw 8B3 for setting a conveyance path between the recording medium from the sheet feeding tray 8A and the recording medium from the manual sheet feeding tray 1B is provided in front of the registration roller 8B2. The route can be switched to be guided to the collective transfer device 9.

Behind the batch transfer device 9, a fixing device 1 for fixing an image transferred onto a recording medium such as transfer paper is provided.
The fixing device 10 is provided with a heating roller 10A having a built-in heater, and a pressure roller 10B which is brought into contact with and interlocks with the heating roller 10A. The recording medium fixed by the fixing device 10 is discharged onto a discharge tray 12 by a discharge roller 11. In FIG. 1, reference numeral 10C denotes an oil application device for preventing transfer of the developer.

In the color image forming apparatus 1 using the photoreceptor belt 2, when the electrostatic latent image of each color is processed by the developing device 5 into a visible image, the visible image is transferred to the transfer belt 6C of the transfer device 6.
To form a full-color image, and the full-color image is collectively transferred to a recording medium.

The color image forming apparatus 1 according to the present embodiment is provided with a configuration in which, when a recording medium in the course of conveyance is jammed on the way, the recording medium can be taken out. FIG. 6 is a diagram showing a configuration for this purpose. The apparatus main body located above the transfer belt 6C provided in the transfer apparatus 6 is divided from other parts and supported by a frame in the apparatus main body. A cover frame 1C that can be opened and closed using the support shaft 1B1 as a fulcrum is configured. On the cover frame 1B side, a batch transfer device 9, a transport roller 8
B1, registration roller 8B2 and transport path switching claw 8
B3 is provided, and these rollers are transferred to the transfer belt 6.
By making contact with and separating from C, it is possible to select between a case where a conveyance path for the recording medium is formed and a case where the transfer belt 6C is exposed. When the cover frame 1C is opened, the transfer belt 6C is exposed, and the recording medium staying at that portion can be taken out. Transfer belt 6C
By moving only the member facing to the transfer belt 6C toward and away from the transfer belt 6C, the members provided in the other image forming processing units maintain the state arranged in the apparatus main body.
By preventing the developer from moving, adverse effects such as scattering and leakage of the developer do not occur.

The developing device 5 includes four developing units containing yellow, magenta, cyan, and black developers having a complementary color relationship with the color separated along the circumferential direction. Constitutes a rotary developing device capable of supplying a developer of a color corresponding to the electrostatic latent image formed on the photosensitive belt 2 opposite to the photosensitive belt 2.

The developing units provided in the rotary developing device 5 have the same configuration, and details thereof are shown in FIG. FIG. 2 shows a state in which one of the developing units faces the photoreceptor belt 2 to perform visible image processing. In FIG. 2, the developing unit (for convenience, a developing unit containing a yellow developer is shown). , Sign Y
5Y has a configuration using a non-magnetic one-component developer. That is, in the developing unit 5Y,
A developing sleeve 5Y1 is provided in which a part of the peripheral surface is exposed from an opening formed in a part of the casing.

The rotation direction of the developing sleeve 5Y1 is set such that it moves in the same direction at a position facing the photosensitive belt 2 at a predetermined peripheral speed ratio with the photosensitive belt 2. The rotation direction of the developing sleeve 5Y1 is set such that the developing sleeve 5Y1 moves in the same direction at a position facing the photosensitive belt 2 at a predetermined peripheral speed ratio. A supply roller 5Y2 for supplying the developer is in contact with the developing sleeve 5Y1. The supply roller 5Y2 is a roller made of an elastic body such as foamed polyurethane, and has a rotation direction in which the supply roller 5Y2 moves in the same direction at the contact position with a predetermined peripheral speed ratio with the developing sleeve 5Y1.

A housing space 5Y3 for housing the developer is provided in a part of the developing unit 5Y.
Between the supply roller 5Y2 and the supply roller 5Y2,
A flicker member 5Y4 that is pressed against the peripheral surface with a predetermined bite amount and a shielding member 5Y5 that is disposed between the flicker member 5Y4 and the housing space 5Y3 are provided.

The flicker member 5Y4 is a member that frictionally charges the developer from the storage space 5Y3 while being carried on the surface of the supply roller 5Y2 and regulates the amount of developer carried on the supply roller 5Y2. At the pressure contact position with 5Y2, a rotation direction of moving in the same direction is set and the rotation is performed.

The shielding member 5Y5 is a blade member for preventing the developer from flowing directly from the storage space 5Y3 toward the developing sleeve 5Y1, and supplies the developer in the storage space 5Y3 between the supply roller 5Y2 and the flicker member 5Y4. Only to be introduced. For this reason, the flicker member 5Y4
The developer is carried on the developing sleeve 5Y1 in a state where the shortage of the charge amount generated in the developer reaching the developing sleeve 5Y1 without passing through the developing sleeve 5Y1 is eliminated.

The developer in the accommodating space 5Y3 reduces the bulk density between the particles due to the air entering between the particles due to the inertia when the rotary developing device 5 rotates, so-called adhesive force between the particles. Has the property of increasing the fluidity by being weakened, exhibits fluidity like a liquid, and can flow out of the storage space 5Y3. For this reason, as shown in FIG. 2, when the opening of the storage space 5Y3 faces downward, that is, when the shielding member 5Y5 is located below the storage space 5Y3, the shielding member 5Y5 directs the toner to the developing sleeve 5Y1. Flow is regulated, and the developer flowing out of the storage space 5Y3 is pumped up by the rotation direction of the supply roller 5Y2. The amount of the developer drawn up by the supply roller 5Y2 is regulated by the cooperation of the supply roller 5Y2 and the flicker member 5Y4, and the required charge amount when the developer is carried on the development sleeve 5Y1 is friction. Set by charging.

The developing unit 5Y includes a developing sleeve 5Y.
A thinning blade 5Y6 is provided in contact with the peripheral surface at a position before facing the photoreceptor belt 2 in one rotation direction. The thinning blade 5Y6 is a member for regulating the developer carried on the developing sleeve 5Y1 into a thin layer having a uniform thickness, and is a thin plate having a spring property such as a stainless steel plate or an elastic material such as urethane rubber. Are supported in a cantilever shape.

In the developing unit 5Y, when the developing sleeve 5Y1 is disposed at a position facing the photoreceptor belt 2 by the rotation of the developing device 5, the developer flows out of the accommodating space 5Y3 and flickers when it is pumped up by the supply roller 5Y2. The amount of toner carried on the supply roller 5Y2 is regulated by the member 5Y4, and is supplied to the developing sleeve 5Y1 after being triboelectrically charged. The developer carried on the developing sleeve 5Y1 is defined as a thin layer having a uniform thickness by the thinning blade 5Y6, and is supplied to the electrostatic latent image on the photosensitive belt 2 by contact or non-contact.

As shown in FIG. 3, each developing sleeve including the developing sleeve 5Y1 is mounted on a rotatable developing unit support member 5F provided in the image forming apparatus. The developing unit supporting member 5F has a length that can accommodate the developing unit, has an end plate 5F2 having an opening 5F1 into which each developing unit can be inserted, at one end in the longitudinal direction, and a motor (not shown) serving as a rotational drive source. Gear 5G, which is a power transmission mechanism, is provided at the other end in the longitudinal direction.

The end plate 5F2 and the gear 5G are arranged along the juxtaposition direction of the respective developing units, and are connected to respective longitudinal ends of a partition wall 5F3 for partitioning the mounting portions of the respective developer units. Although FIG. 3 shows only a developing unit for yellow developer denoted by reference numeral 5Y, each of the cyan, magenta, and black developing units (not shown) is a developing unit support member similarly to the developing unit 5Y. 5
F can be inserted and removed through the opening 5F1.

The developing unit supporting member 5F is driven by a motor (not shown) as a drive source for transmitting a driving force to the gear 5G. Are driven to rotate in a state in which they do not face the photosensitive belt 2 and in a state in which the developing sleeve faces the photosensitive belt 2.

FIG. 4 shows the arrangement of the respective developing units at the home position of the developing device 5. In FIG. 4, the developing unit 5Y containing the yellow developer is moved in the rotation direction of the developing device 5 (the direction of the arrow in the drawing). The positional relationship between the developing units is determined such that the developing units are first opposed to the photoreceptor belt 2 during image formation. For this reason, when the developing device 5 is set at the home position, the developing sleeve 5Y of the developing unit 5Y containing the yellow developer is used.
When the developing unit 5Y is the starting point in the rotation direction of the developing device 5 and the developing sleeve 5B1 of the developing unit 5B containing the black developer located rearmost, the intermediate position between the developing sleeve 5B1 and the photosensitive belt 2 is opposed. It has become. At the time of image formation, as shown in FIG. 5, the developing unit (developing unit indicated by reference numeral 5Y) is tilted from the home position shown in FIG. 4 such that the developing sleeve in the developing unit faces the photoreceptor belt 2. .

In FIGS. 3 and 4, reference numerals 5YT, 5C
The members denoted by T, 5MT, and 5BT indicate tanks that are developer replenishing members that communicate with the accommodation spaces 5Y3, 5C3, 5M3, and 5B3 of each developing unit. The developer replenishing tank (for convenience, in FIG. As shown in FIG. 3, the developing unit 5YT is connected to one end of the developing unit 5Y in the longitudinal direction. Although FIG. 3 shows only the developing unit 5Y containing the yellow developer, other developing units are similarly provided with a developer replenishing tank. Developer replenishment tank 5YT, 5CT, 5MT, 5BT
Are developer storage spaces 5Y3, 5C3, 5M3, 5B3
This is provided to take in the developer in conjunction with the rotation of the developing unit.

The inside of the developer replenishing tanks 5YT, 5CT, 5MT, and 5BT having a structure capable of flowing the developer housed therein into the housing space is provided for detecting the remaining amount of the developer. A configuration is provided. FIGS. 5, 7, and 8 are diagrams showing a configuration for detecting the remaining amount of the developer. In FIGS. 5 and 7, the remaining amount detecting means for detecting the remaining amount is a developer replenishing tank. 5YT, 5
Light transmitting means 20Y, 20C, 20M, and 20B provided inside the CT, 5MT, and 5BT; , As shown in FIG.
The optical sensor 21 includes a control unit 22 connected to the input side.

As shown in FIG. 8, the light transmitting means 20Y, 2Y
0C, 20M and 20B are spaced apart from each other to form a space in which the developer can be interposed (indicated by S for convenience), and the developer replenishment tanks 5YT, 5CT and 5M
T, 5BT (in FIG. 7, 5YT is shown as a target), and is constituted by a triangular concave portion 5YT4 bulging toward the inside. The recess 5YT4 is positioned so as to face a window 5YT3 (see FIG. 7) formed on the peripheral wall 5YT1 of the developer replenishing tank 5YT, and has a 45 ° inclined side 5YT4A and a developer from the top of the inclined side 5YT4A. A vertical side 5 perpendicular to the peripheral wall 5YT1 of the refill tank 5YT
YT4B. Slope 5 between recesses 5YT4
YT4A is arranged in an opposed state.

The vertical side 5YT4B is constituted by a transparent portion,
The inclined side 5YT4A is a reflecting surface using a reflecting tape or the like. The reflective tape is attached to the inner surface of the developer replenishment tank 5YT in the concave portion 5YT4, thereby simplifying the installation procedure. In addition, instead of the reflective tape, the inclined side 5Y
It is also possible to deposit a reflective material on the inner surface of T4A, or to use a material equivalent thereto. In this embodiment, the peripheral wall 5Y of the developer replenishment tank 5YT in which the bases of the inclined side 5YT4A and the vertical side 5YT4B are integrated.
T1 is an opaque material or an opaque material,
For example, a material such as black polycarbonate is applied.

As shown in FIG. 5, the optical sensor 21 has a window portion (reference numeral 5Y in FIG. 7) of the developing unit located at the lowest position where the developer can be concentrated downward by gravity.
(A portion indicated by T3) is provided in an immovable portion (not shown).

As shown in FIG. 8, the optical sensor 21 includes a light emitting element 21A for emitting detection light toward one of the light transmitting means 20Y and a light receiving element 21B for receiving light from the other of the light transmitting means 20Y. Have. The light emitted from the light emitting element 21A reaches the light receiving element 21B with the shortest optical path length via the 45 ° inclined side 5YT4A, and the light transmission state in the space S located in the middle of the optical path. Is output from the light receiving element 21B.

The optical sensor 21 is electrically connected to the control unit 22. The main part of the control unit 22 is configured by a microcomputer, and is related to the present embodiment via an I / O interface (not shown). The control unit 22 has a light receiving element 21B on the input side and a light emitting element 21A on the output side. Alarm means 23 described later is connected. Control unit 22
Is for determining and determining the remaining amount of the developer based on a signal from the optical sensor 21.
1 to prevent erroneous detection when detecting the remaining amount according to the light transmission state. The optical sensor 21 has the concave portion 5Y
Due to the fact that the developer present in the space S between T4 (see FIG. 8) remains attached to the transparent portion or the optical transmission state changes when the optical axis is shifted. It may not be possible to accurately determine the remaining amount detection state. For this reason, in the present embodiment, while the remaining amount of the developer is detected by the optical sensor 21, erroneous detection by the optical sensor is prevented.

The controller 22 outputs a light emission command to the light emitting element 21A and detects the remaining amount by taking in an output signal from the light receiving element 21B at that time in order to detect the remaining amount every time an image is formed. At the same time, the number of remaining amount detections (n) corresponding to the capture of the output signal is accumulated, and when the accumulated number (n) is equal to or more than a predetermined number (100 times), the developer cannot be replenished. By judging that the end state is approaching, a new replenishment of the developer, that is, a replacement of the developer replenishment tank is warned. Therefore, when an output signal indicating that the remaining amount of the developer is exhausted is obtained from the output signals corresponding to the light transmission state in the optical sensor 21, the accumulated number of the remaining amount detection is increased. Since the warning that the developer needs to be replenished for the first time is given when the predetermined number of times has been reached, a part of the developer is accumulated while the amount of the developer that can actually form an image is offset. It is possible to accurately grasp the case where the optical sensor 21 does not actually exist in the space S between the concave portions 5YT4 or the abnormality of the optical sensor 21 due to the change in the optical characteristics or the like. As a result, it is possible to accurately detect that the state in which the developer cannot be replenished actually approaches, that is, a state in which image formation is disabled.

FIG. 9 is a flowchart for explaining the operation of the control unit 22. In the drawings after FIG. 9, the developer is described as toner. In FIG. 9, in the remaining amount detection process, image formation, that is, image formation is started (ST1), and the developer (toner) is near-end, that is,
It is determined whether or not the light transmission state has been obtained based on the signal from the optical sensor 21 (ST2). If the light transmission state has been obtained, the number of detections is counted up (ST2).
3).

When the number of detections is accumulated, it is determined whether or not the number has reached a predetermined number (100 times) (ST).
4), it is determined that the developer is being replenished and the user is warned through the warning means 23 (ST).
5). In this case, the alarm means 23 uses a medium using a display or an alarm sound.

In the case shown in FIG. 8, it is assumed that the detection of the remaining amount is performed for each image formation. However, the present invention is not limited to this. The opportunity for correcting the characteristics may be set as the timing for detecting the remaining amount.

On the other hand, depending on the state of use, the image formation may be continued to some extent after the warning is issued, even though the developer needs to be replenished. In this case, the developer completely disappears, and an abnormal image such as insufficient density or uneven color occurs. In the present embodiment, the occurrence of an abnormal image is prevented on the assumption that the image formation is continued even after the developer replenishment warning is issued. Control unit 2
In step 2, when the image formation is continued after the developer replenishment warning is issued, the number of times when the transmission state is obtained by the signal from the optical sensor 21 is accumulated, and the accumulated number reaches the predetermined number. Then, while alerting that the developer has completely run out, a process of automatically stopping the image forming apparatus until new developer is replenished is performed. FIG. 10 is a flowchart for explaining the processing in this case. In FIG. 10, the optical sensor 21 after warning that the developer needs to be replenished in step ST5 is issued.
The number of times that the state where the light has been transmitted is obtained by the signal from, and when the accumulated number (n) reaches a predetermined number (200 times), it is determined that the developer (toner) has completely disappeared. An alarm is issued and the image forming (image forming) process is forcibly terminated, and the image forming apparatus (machine) is stopped until new developer is replenished, that is, the developer replenishment tank is replaced (ST6). ST7).

In the present embodiment, a new replenishment of the developer, that is, the developer replenishment cartridge is surely replaced by utilizing the change in the remaining amount of the developer when the replenishment of the new developer is performed. Can be determined. That is, when the remaining amount is not detected by the optical sensor 21 every time as described above, if the developer is accumulated in the space S between the recesses 5YT4, a new developer is replenished. It may be incorrectly determined that replenishment has been performed even though the replenishment has not been performed. When such a determination is made, correction of development characteristics, so-called process control, is executed even though there is no newly replenished developer, and an image having abnormal image density and gradation is obtained. Will be obtained.

In this embodiment, in order to avoid such a phenomenon, the optical sensor 21 determines whether or not a new developer has been replenished, in other words, whether the developer replenishment cartridge has been replaced.
It is determined that a new signal has been exchanged only when a signal in a state of not transmitting light is output a predetermined number of times. That is, after the developer replenishment cartridge is newly replaced, the flow amount of the developer increases, and the optical path of the optical sensor 21 is often blocked by the developer. Therefore, the replacement of the cartridge is performed for this phenomenon. Judge whether or not. FIG. 11 is a flowchart for explaining the operation in this case. In FIG. 11, when the power is turned on or the door of the developing unit take-out section in the apparatus main body is opened (ST10), step ST1 is performed.
The remaining amount detection result of the developer at the stage before the process of 0 is executed is determined (ST11).

In step ST11, step ST10
When the cause of performing the processing of (1) is determined, and it is determined that the developer needs to be newly replenished, in other words, the developer replenishment cartridge needs to be replaced, the remaining number of times of detection is set to the initial value (0). It returns (ST12). As the door opened in step ST10 is closed and image formation is started, a predetermined number of remaining amount detections are performed (ST13),
If it is not determined from the signal from the optical sensor 21 that the remaining amount of the developer is small, it is determined that the developer replenishment cartridge has been replaced and the process control is performed (ST14), and the image forming process is awaited. (ST15).

On the other hand, when the remaining amount is detected, the number is accumulated (ST16), and it is determined from the signal from the optical sensor 21 that the remaining amount of the developer is insufficient even at the accumulated number (ST17). A warning is issued to request replacement of the developer replenishment cartridge (ST18). As a result, the optical sensor 21 is not actually replaced.
Even if the same condition as that when the exchange is performed is obtained by the signal from the CPU, the case where the exchange is not performed can be determined by detecting the remaining amount of the developer when the image forming process is actually performed.

[0056]

According to the first and second aspects of the present invention, the remaining amount detection means accumulates the number of remaining amount detections separately from the remaining amount detection which is determined based on a signal from the optical sensor. It is possible to determine the degree of consumption over time separately from the signal of the above, and it is possible to accurately determine the actual remaining amount from the degree of consumption even if erroneous detection of the optical sensor occurs. As a result, the remaining amount of the developer can be always accurately determined with a simple configuration using only the existing optical sensor, and
This can be performed without increasing the cost or increasing the size of the apparatus.

According to the third and fourth aspects of the present invention, the remaining amount of the developer is constantly detected for the occasion where the developer is consumed. The state can be accurately determined.

According to the fifth and sixth aspects of the present invention, whether or not new developer is replenished can be determined by detecting the remaining amount of the predetermined number of times. Can be performed using an existing optical sensor without requiring a special configuration for detecting the developer, it is possible to accurately determine whether or not a new developer replenishment state is required without increasing the cost. As a result, it is possible to prevent an abnormal image from being obtained due to the correction of the developing characteristic which is erroneously determined to be the same state even though the new developer is not replenished. It becomes possible.

According to the present invention, the remaining amount of the developer can be detected by judging the degree of consumption using the cumulative number of times of detection, so that the optical sensor can be used simply by using an existing optical sensor. Accurate detection can be performed while avoiding erroneous detection of the sensor. This makes it possible to prevent the occurrence of an abnormal image without increasing the cost due to an increase in the size and complexity of the configuration. In addition, since the existing optical sensor can determine whether or not the replenishment of the developer has been performed, the configuration can be simplified.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a main part of an image forming apparatus according to an example for describing an embodiment of the present invention.

FIG. 2 is a schematic diagram for explaining a configuration of a developing unit provided in a developing device used in the image forming apparatus shown in FIG.

FIG. 3 is a perspective view of a main part for describing a support structure of a developing unit used in the image forming apparatus shown in FIG.

FIG. 4 is a schematic side view illustrating one embodiment of a developing unit supported by the support structure shown in FIG. 3;

FIG. 5 is a schematic side view for explaining another embodiment of the developing unit supported by the support structure shown in FIG. 3;

FIG. 6 is a schematic diagram for explaining one embodiment of the image forming apparatus shown in FIG.

FIG. 7 is a perspective view of a developing unit used in the image forming apparatus shown in FIG.

FIG. 8 is a partial view for explaining a configuration of a developer remaining amount detecting unit provided in the developing unit shown in FIG. 7;

FIG. 9 is a flowchart for explaining one operation of a control unit used in the remaining developer amount detection unit shown in FIG. 8;

FIG. 10 is a flowchart illustrating another operation of the control unit used in the developer remaining amount detection unit illustrated in FIG. 8;

FIG. 11 is a flowchart for explaining another operation of the control unit used in the developer remaining amount detecting means shown in FIG.

[Description of Signs] 1 Color image forming apparatus as one of image forming apparatuses 2 Photoreceptor belt as latent image carrier 3 Charging device 4 Optical writing device 5 Developing device 5Y, 5C, 5M, 5B Developing unit 5Y1, 5C1 5M1, 5B1 Developing sleeve 5YT, 5CT, 5MT, 5BT Developer replenishing tank 20Y, 20C, 20M, 20B Light transmitting means 21 which is a component of remaining amount detecting means 21 Optical sensor used for remaining amount detecting means 22 Remaining amount Control unit used for detecting means 23 Warning means

Claims (10)

[Claims] 1. A developing device for visualizing a latent image on a latent image carrier, comprising: a remaining amount detecting unit for developer supplied to the latent image carrier, wherein the remaining amount detecting unit counts the number of remaining amount detections. , And the remaining amount of the developer is determined based on the number of times of accumulation. 2. The developing device according to claim 1, wherein the remaining amount detecting means includes a pair of light transmitting means disposed inside the developer replenishing member used for replenishing the developer with a space for interposing a developer therebetween, and the developing means. An optical sensor disposed outside the agent replenishing member and opposed to the light transmitting means, and a control unit in which the optical sensor is connected to an input side and an alarm means is connected to an output side; 2. The control unit according to claim 1, wherein when the cumulative number of remaining amount detections by the optical sensor based on the light transmission state reaches a predetermined number, the controller notifies that the developer cannot be replenished. Developing device. 3. The apparatus according to claim 1, wherein the remaining amount detecting means detects the remaining amount of the developer every time the visible image processing is performed on the latent image carrier. Developing device. 4. The developing device according to claim 1, wherein said remaining amount detecting means detects the remaining amount of the developer every time the developing characteristic is corrected each time a predetermined number of images are formed. . 5. The apparatus according to claim 1, wherein the remaining amount detecting means determines that new developer has been replenished by the output signal from the optical sensor when the controller determines that there is no remaining amount of developer. The developing device according to claim 1, wherein: 6. The apparatus according to claim 1, wherein the remaining amount detecting means determines that a new developer has been replenished when an output signal from the optical sensor is not obtained continuously for a certain number of times or more in the controller. The developing device according to claim 5, wherein 7. An image forming apparatus provided with a developing device capable of supplying developers of a plurality of colors to a latent image carrier, wherein the developing device comprises a plurality of developing units arranged in a circumferential direction and rotated. A rotatable developing device, wherein the developing unit is provided with a detachable developer replenishing member containing the developer, and is provided with a developer remaining amount detection unit at the developer replenishing member; The image forming apparatus according to claim 1, wherein the remaining amount detecting means accumulates the number of times of remaining amount detection, and determines that the remaining amount of the developer is exhausted according to the accumulated number of times. 8. A pair of light transmitting means disposed inside a developer replenishing member used for replenishing the developer, wherein the pair of light transmitting means is provided with a space in which a developer is interposed. An optical sensor disposed outside the developing developer replenishing member so as to face the light transmitting unit, and a control unit in which the optical sensor is connected to an input side and an alarm unit is connected to an output side, The control unit alerts that developer replenishment becomes impossible when the cumulative number of remaining amount detections reaches a predetermined number, separately from the determination of the light transmission state using the optical sensor. Item 8. The image forming apparatus according to Item 7. 9. The residual amount detecting means, when the control section determines that there is no residual amount of developer, notifies the replacement of the developer replenishing member by an output signal from the optical sensor. 8. The method according to claim 7, wherein the determination is possible.
Or the image forming apparatus according to 8. 10. The apparatus according to claim 1, wherein the remaining amount detecting means determines that the replacement of the developer replenishing member is completed when the optical sensor does not transmit light a predetermined number of times after the replacement of the developer replenishing member. The image forming apparatus according to claim 9.