JPH08328366A - Color image forming device - Google Patents

Abstract

PURPOSE: To achieve maintenance efficiency and a compact recovery container by recovering all of used two-component developer and waste toner from a plurality of developing units into one area, thereby reducing the number of times that they are disposed of. CONSTITUTION: A developer recovery container 31 comprises a developer recovery part 312 and a waste-toner recovery part 311. Waste toner scraped by a cleaning blade 19a and a cleaning roller 19b is discharged into the waste-toner recovery part 311 of the developer recovery container 31 via a toner carrying screw 19c and a toner carrying pipe 19d. Also, at the time of the supply of unused two-component developer, used two-component developer which has flowed over the shelf of the developing unit 13K is discharged out of the unit 13K by means of a developer recovery screw 138K and is recovered into the developer recovery part 312 of the developer recovery container 31 via a developer carrying pipe 141K. In each of the other developers Y, M, and C, used two-component developer is recovered into the developer recovery part 312 in the same way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic copying machine, printer, and F for forming an image using a two-component developer.
The present invention relates to a color image forming apparatus including a replenishment developer supply container used for a color image forming apparatus such as an AX and a recovery developer collection container.

[0002]

2. Description of the Related Art As a method of forming a multicolor image, a monochromatic toner image formed on each of the photoconductors is transferred by using a photoconductor, a charging device, a developing device and the like of the same number of images as necessary. A color image forming apparatus that forms a color image by superimposing the same on one or more of the above, and one photosensitive member is rotated a plurality of times to charge each color,
A color image forming apparatus which forms a color image by repeating image exposure and development, or a color image forming which forms a color image by sequentially performing charging, image exposure and development for each color within one rotation of one photosensitive member. Devices and the like are known.

[0003]

However, in each of the color image forming apparatuses described above, the structure is complicated because a large number of developing devices are arranged with respect to the image forming body, and the attaching / detaching operation of the image forming body and the developing device becomes complicated. And handling is poor. Further, recently, due to the long life of the image forming body, an image forming body that can withstand 100 to 1 million copies is generally used and it is becoming unnecessary to replace the image forming body. However, a developing device using a two-component developer is used. In the above, the developer is deteriorated by being agitated when the developer is used, and it is necessary to replace the two-component developer with a durability of about 5,000 to 50,000 copies. In particular, in a plurality of developing devices provided in a color image forming apparatus, yellow (Y), magenta (M), cyan (C) used in color image formation must be used unless effective two-component developer is replaced. The two-component developer is not uniformly deteriorated for each color due to the difference in the use frequency of the black and black (K) developing devices, or the toner density of each developing device is different during use, and thus the two-component developer is formed. A good color image cannot be obtained because the color balance of the color image changes.

The present invention solves this problem and improves it.
Efficiently exchange and collect the deteriorated developer of the two-component developer used in the multiple developing devices used in the color image forming apparatus, and supply unused toner or two-component developer to obtain the color. Color that forms a color image with good color balance that prevents uneven deterioration of the two-component developer due to the difference in the usage frequency of each developing device and color difference due to the difference in toner concentration during use. The purpose is to provide an image forming apparatus.

[0005]

SUMMARY OF THE INVENTION The above object is to provide a color image forming apparatus having a plurality of developing devices using a two-component developer composed of toner and carrier and a cleaning device for cleaning residual toner on the image forming body. A color image forming apparatus comprising: a developer collecting container for collecting used two-component developer discharged from each of the plurality of developing devices and waste toner discharged from the cleaning device. Achieved (first invention).

Further, the above-mentioned object is to recover a used two-component developer discharged from each of a plurality of developing devices using the two-component developer composed of toner and carrier and the plurality of developing devices. In a color image forming apparatus including a container, a carrier storage container that stores a carrier and a developer storage container that supplies toner to each of the developing units are provided, and the carrier storage container and the developer storage container are The used two-component developer is discharged from the developing device into the developer collecting container according to a predetermined number of times of use of the two-component developer housed in the plurality of developing devices. Unused carrier is supplied from the carrier storage container to the corresponding developing device, and unused toner is supplied from the developer storage container to the corresponding developing device during copying. Is accomplished by a color image forming apparatus according to claim is that the (second invention).

Further, the above-mentioned object is to recover a used two-component developer discharged from each of a plurality of developing devices using the two-component developer composed of toner and carrier and the plurality of developing devices. In a color image forming apparatus including a container, a developer storage container in which toner and a carrier are separately stored is detachably provided in each of the developing units, and a used two-component developer is used for the development. The unused developer is supplied to the corresponding developing device from the developer storage container by being discharged from the developer storage container to the corresponding developer container, and the unused toner from the developer storage container during copying. Is supplied to the corresponding developing device (3rd invention).

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An image forming process and each mechanism of an embodiment of a color image forming apparatus which constitutes the present invention will be described with reference to the color image forming apparatus shown in FIG. FIG. 1 is a sectional configuration diagram of a color image forming apparatus showing an embodiment of the present invention.

The photosensitive drum 10, which is an image forming body, is provided with, for example, a cylindrical base body formed of a transparent member such as optical glass or transparent acrylic resin inside, and a transparent conductive layer, a- A photosensitive layer such as a Si layer or an organic photosensitive layer (OPC) is formed on a drum, and is driven and rotated clockwise in a grounded state.

In this embodiment, in the photoconductor layer of the photoconductor drum, which is the image formation point of the exposure beam for image exposure, an appropriate contrast is obtained with respect to the light attenuation characteristics (photocarrier generation) of the photoconductor layer. It suffices that the exposure light amount has a wavelength that can be applied. Therefore, the light transmittance of the transparent substrate of the photosensitive drum in the present embodiment does not need to be 100%, and may have a characteristic that some light is absorbed when the exposure beam is transmitted. As a material of the translucent substrate, various translucent resins such as soda glass, Pyrex glass, borosilicate glass and fluorine used for general optical members, polyester, polycarbonate, polyethylene terephthalate and the like can be used. Further, as the translucent conductive layer, indium tin oxide (ITO), tin oxide,
Lead oxide, indium oxide, copper iodide, Au, Ag, N
A metal thin film made of i, Al or the like and maintaining a light-transmitting property is used.
Various sputtering methods, various CVD methods, dip coating methods, spray coating methods and the like are used. As the photoconductor layer, an amorphous silicon (a-Si) alloy photosensitive layer,
Amorphous selenium alloy photosensitive layer and various organic photosensitive layers (O
PC) can be used. The scorotron chargers 11Y, 11M, 11C, and 11K, which are charging means, are used in the image forming process of each color of yellow (Y), magenta (M), cyan (C), and black (K), and the above-mentioned photosensitive drum 10 is used. The organic photoconductor layer is charged by a control grid held at a predetermined potential and a corona discharge by a discharge wire to give a uniform potential to the photoconductor drum 10.

Exposure optical systems 12Y and 12 which are image exposure means
M, 12C and 12K are linear FL (phosphor light emission), EL (electroluminescence), PL in which light emitting elements arranged in the axial direction of the photoconductor drum 10 are arranged in an array.
(Plasma discharge), LED (light emitting diode), linear LISA (photomagnetic effect optical shutter array) in which elements having an optical shutter function are arranged, PLZT (transmissive piezoelectric element shutter array), LCS (liquid crystal shutter), etc. Of the exposure element and a SELFOC lens as an equal-magnification imaging element, which is attached to a support member 20 provided inside the photosensitive drum 10 and read by a separate image reading device. The image signals of the respective colors thus obtained are sequentially taken out from the memory, and the exposure optical systems 12Y, 12
The electric signals are input to M, 12C and 12K, respectively. The emission wavelength of the light emitting device used in this example is
Considering the light advancing property of the toner, use the one with a long wavelength.
In the range of up to 900 nm.

A developing device 13 which is a developing means using a non-contact developing method for accommodating two-component developers of yellow (Y), magenta (M), cyan (C) and black (K), respectively.
Each of Y, 13M, 13C, and 13K includes a developing sleeve 131Y, 131M, 131C, and 131K that rotates with a predetermined gap with respect to the peripheral surface of the photosensitive drum 10.

The developing units 13Y, 13M, 13C and 13K are the scorotron chargers 11Y and 11 described above.
Charging by M, 11C and 11K, exposure optical system 12Y,
The electrostatic latent image formed on the photosensitive drum 10 by image exposure with 12M, 12C and 12K is reversely developed in a non-contact state by applying a developing bias voltage.

The original image is temporarily read as an image signal for each color of Y, M, C and K from an image read by an image pickup device or an image edited by a computer in an image reading apparatus separate from this apparatus. Stored and stored in memory.

When the image recording is started, the photoconductor drive motor is rotated to rotate the photoconductor drum 10 clockwise.
At the same time, application of electric potential to the photoconductor drum 10 is started by the charging action of the scorotron charger 11Y.

After a potential is applied to the photosensitive drum 10, the exposure optical system 12Y starts exposure by an electric signal corresponding to a first color signal, that is, an image signal of yellow (Y), and the drum is rotationally scanned. An electrostatic latent image corresponding to the yellow (Y) image of the original image is formed on the photosensitive layer on the surface thereof.

A developing device 13 in which the latent image is rotated and operated.
The toner of the two-component developer on the Y developing sleeve is subjected to reversal development in a non-contact state to form a yellow (Y) toner image according to the rotation of the photosensitive drum 10.

Next, the photosensitive drum 10 is further provided with a scorotron charger 11 on the yellow (Y) toner image.
An electric potential is given by the charging action of M, and the exposure optical system 12M
Of the yellow (Y) toner image by the non-contact reversal development of the developing device 13M which is exposed to an electric signal corresponding to the second color signal, that is, the image signal of magenta (M), and rotated and operated. A magenta (M) toner image is sequentially formed on the top of the toner image.

By the same process, rotation of the scorotron charger 11C, the exposure optical system 12C and the developing device 13C,
By the operation, the cyan (C) toner image corresponding to the third color signal is further generated, and the scorotron charger 11K,
By rotation and operation of the exposure optical system 12K and the developing device 13K, a black (K) toner image corresponding to the fourth color signal is sequentially superposed and formed on the peripheral surface of the photosensitive drum 10 within one rotation. A color toner image is formed.

These exposure optical systems 12Y, 12M, 12C
The exposure of the organic photosensitive layer of the photoconductor drum 10 with the light of 12K and 12K is performed from the inside of the drum through the transparent substrate. Therefore, the exposure of the image corresponding to the second, third and fourth color signals is performed without any influence of the toner image previously formed, and is equivalent to the image corresponding to the first color signal. It is possible to form an electrostatic latent image. In order to stabilize the temperature inside the photoconductor drum 10 and prevent the temperature from rising due to the heat generated by the exposure optical systems 12Y, 12M, 12C and 12K, a material having good thermal conductivity is used for the supporting member 20, and when the temperature is low, By using a heater and taking measures such as radiating heat to the outside through a heat pipe when the temperature is high, it is possible to suppress the heat to a degree that does not cause any trouble.

Toners for replenishment of each color or unused two-component developers, which will be described later, open the upper opening / closing lid 7 of the apparatus main body and are detachable in the direction of the arrow shown in FIG.
From Y, 21M, 21C and 21K, developing unit 13Y, 1
Replenished to 3M, 13C and 13K. Developer 13
During the developing operation by Y, 13M, 13C and 13K, the developing sleeves 131Y, 131M and 131, respectively.
A developing bias in which a direct current or an alternating current is applied to C and 131K is applied, jumping development is performed by a two-component developer housed in the developing device, and toner is applied to the photosensitive drum 10 that grounds the transparent conductive layer. By applying a DC bias of the same polarity, non-contact reversal development in which toner adheres to the exposed portion is performed.

Thus, the color toner image formed on the peripheral surface of the photosensitive drum 10 is transferred by the transfer device 14a.
The timing roller 1 is fed from the paper feed cassette 15.
6 and is driven by the timing roller 16
It is transferred onto a transfer paper P that is a transfer material that is fed in synchronization with the toner image on the photoconductor drum 10.

The transfer paper P having the toner image transferred thereto is removed from the charge in the static eliminator 14b and separated from the peripheral surface of the drum, and is then transported to the fixing device 17 by the transport belt 14e. After the toner is welded and fixed on the transfer paper P by being heated and pressure-bonded in the fixing device 17, the toner is discharged from the fixing device 17 and is conveyed by the pair of paper discharging / conveying rollers 18 a, and is discharged onto the tray on the upper part of the device through the paper discharging rollers 18. Is discharged to.

On the other hand, the photosensitive drum 10 from which the transfer paper is separated
In the cleaning device 19, the surface of the photoconductor drum 10 is rubbed by the cleaning blade 19a in the cleaning device 19 to remove the residual toner, and the toner image of the original image is continuously cleaned or temporarily stopped, or the toner image of the new original image is temporarily stopped. Take formation. The waste toner scraped off by the cleaning blade 19a and the cleaning roller 19b is discharged to the developer collecting container 31 through the toner carrying screw 19c and the toner carrying pipe 19d.
After the cleaning is completed, the cleaning blade 19a and the cleaning roller 19b are kept apart from the photoconductor drum 10 in order to prevent damage to the photoconductor drum 10.

An embodiment of the developer recovery used in the present invention will be described with reference to FIGS. 2 and 3. FIG. 2 is a main part diagram showing an embodiment of the developer recovery, and FIG. 3 is a diagram showing a cross section of the developing device. Developing devices 13Y, 13M, 13C and 1
Since the structure and function of 3K are the same, the developing device 13K
Will be explained on behalf of.

The fixed magnet 132K is the developing sleeve 131.
It is included in K, has N and S magnetic poles arranged alternately, is fixed concentrically with the developing sleeve 131K, and exerts a magnetic force on the peripheral surface of the non-magnetic sleeve.

Thin layer forming rod 133K as a thin layer forming member
Is a member that regulates the layer thickness of the two-component developer on the peripheral surface of the developing sleeve 131K, and is made of a metal material having a circular cross section of a magnetic material having a diameter of 3 to 10 mm, and is an elastic member 13 such as a foam material.
By the urging force of 9K, the peripheral surface of the developing sleeve 131K is uniformly pressed with a predetermined load.

A scraper 134K which is a removing means for removing the two-component developer from the developing sleeve 131K.
Is made of a plate-shaped elastic member such as SUS or urethane rubber, which is provided by pressing one end of the long side of the band in parallel with the developing sleeve 131K.

The stirring screws 136K and 137K are
The toner and the carrier in the developing device 13K are agitated and mixed by rotating at a constant speed in mutually opposite directions to obtain a two-component developer that uniformly contains a predetermined toner component. Further, the two-component developer in which the toner components are evenly stirred and mixed by the supply roller 135K is mixed with the developing sleeve 131K and the thin layer forming rod 13.
It is transported and supplied to the pressure contact part with 3K.

The developer recovery container 31 has a developer recovery section 312.
And a waste toner collecting unit 311. The waste toner scraped off by the cleaning blade 19a and the cleaning roller 19b from the surface of the photoconductor drum 10 in the cleaning device 19 is removed by the toner conveying screw 1.
The toner is discharged to the waste toner collecting section 311 of the developer collecting container 31 through 9c and the toner carrying pipe 19d. Further, when supplying a carrier or an unused two-component developer from a developer storage container 21K, which will be described later, the used two-component developer overflowing the shelf 140K of the developing device 13K is sometimes developed by the developer recovery screw 138K. It is discharged from the container 13K and is collected in the developer collecting section 312 of the developer collecting container 31 through the developer carrying pipe 141K.

Similarly, other developer storage containers 21Y, 21
To supply the carrier from M and 21C or the unused two-component developer, the used two-component developer from the developing devices 13Y, 13M and 13C is used as the developer recovery screw 138.
The toner is discharged by the Y, 138M, and 138C, and is collected in the developer collecting section 312 of the developer collecting container 31 through the developer carrying pipes 141Y, 141M, and 141C. Therefore, the used two-component developer from the developing devices 13Y, 13M, 13C and 13K is collected in the developer collecting section 312 at one place.

In the above embodiment, the waste toner collecting section and the developer collecting section are provided as separate bodies to provide the developer collecting container. However, the waste toner collecting section and the developer collecting section are integrated to collect the developer. It is also possible to collect waste toner and used two-component developer in one container in the developer recovery section by providing a container,
By collecting all used two-component developer and waste toner from multiple developing devices in one place, maintenance efficiency is improved by reducing the number of wastes, and waste toner recovery amount and developer recovery amount become toner consumption amount. Due to the proportionality, the size of the collection container can be reduced, and hence the color image forming apparatus main body can be downsized.

Another embodiment of recovering the developer used in the present invention will be described with reference to FIG. FIG. 4 is a principal part diagram showing another embodiment of the developer recovery. The developing device is the same as that of the above-described embodiment described with reference to FIG.

When the carrier or the unused two-component developer is supplied from the developer accommodating containers 21Y, 21M, 21C and 21K, the used two-component developer is sometimes recovered from the developing devices 13Y, 13M, 13C and 13K. Screw 13
8Y, 138M, 138C and 138K, and is temporarily discharged to the cleaning device 19 through the developer transport pipes 141Y, 141M, 141C and 141K. Further, the waste toner scraped off from the surface of the photosensitive drum 10 by the cleaning blade 19a and the cleaning roller 19b and the used two-component developer are integrated, and the developer is passed through the toner transport screw 19c and the toner transport pipe 19d. It is collected in the collection container 32.

An embodiment of the developer supply according to the present invention will be described with reference to FIGS. FIG. 5 is a diagram showing an embodiment of a developer supply mechanism and control, and FIG. 6 is a schematic diagram showing the carrier storage container and the developer storage container of FIG. The developing device is similar to that of the embodiment described in FIG.
In this embodiment, the developer accommodating container and the carrier accommodating container can be replaced in the same developing device.

The developer accommodating container 21K is provided with a toner accommodating portion 211K for accommodating black toner therein, and is sandwiched between bottom plates 415K and 416K to provide the toner replenishing roller 21K.
3K is provided. Both ends of the toner replenishing roller 213K are rotatably supported by the side wall of the developer accommodating container 21K and rotated by a gear 214K provided on one side. The supply opening 217K at the lower portion of the developer accommodating container 21K has a seal member 218.
Sealed by K. With toner loaded,
The top is sealed.

The carrier accommodating container 510K is provided with a carrier accommodating portion 212K in which a carrier is accommodated.
A carrier replenishing roller 513K is provided between the bottom plates 415K and 416K. Carrier supply roller 513K
Is rotated at its both ends by a gear 214K that is rotatably supported by the side wall of the carrier storage container 510K and is provided on one side. The supply opening 217K at the bottom of the carrier storage container 510K is sealed by the seal member 218K. The top is sealed with the carrier loaded.

The control unit 201 provided in the main body of the color image forming apparatus includes a CPU 202 and a non-volatile RAM 203.
And the ROM 204, and receives an input signal from the operation unit 205 or various sensors, for example, a signal from the toner concentration detection sensor 139K provided in the developing device 13K, and outputs the output unit 206 such as image forming process control or a counter of the apparatus main body. Performs on / off control of control devices such as motors, clutches and solenoids.

A color image is formed by a copy signal from a copy button from the operation unit 205. At that time, the cumulative value of the number of copies for each color used for forming the color image, that is, the developing device for each color is used. Use frequency value is non-volatile RAM
It is stored in 203. The value of the frequency of use of the developing device is stored in the ROM
Each developing device 13Y, 13 for each color stored in 204
Use life of the two-component developer of M, 13C and 13K,
In this embodiment, when the value of the frequency of use of the black developing device 13K reaches the value of the number of times of use of the black two-component developer,
The developer exchange signal is output from the control unit 201 to the operation unit 205, and the developer exchange signal provided on the operation unit 205, for example, a lamp or a liquid crystal display is turned on. On this occasion,
The copy function of the device body is stopped. The lighting timing is preferably when the toner in the developer container is empty.

A user or a service person removes the used developer storage container 21K from the main body of the apparatus, and the unused carrier storage container 510K is replaced with the developing device 13K.
Mounted on the top of the. With the seal member 218K removed, the developing device drive motor and the replenishment motor are rotated and driven in response to a command from the control unit 201 in response to a loading signal from a loading button provided on the operation unit 205. A developing sleeve 131K, a supply roller 135K, stirring screws 136K and 137K, and a developer recovery screw 1 provided on the developing device 13K by driving a developing device drive motor (not shown).
38K is rotated respectively. Further, the carrier replenishing roller 513K is rotated by the drive of the gear 214K by the rotation of the replenishing motor (not shown).

An unused carrier is poured into the developing device 13K from the carrier accommodating portion 212K of the carrier accommodating container 510K, and the used two-component developer is discharged from the developing device 13K as described in the above embodiment. It All unused carriers in the carrier storage portion 212K are the developing devices 13.
The replenishment motor is temporarily stopped by a detection signal of an empty detection sensor (not shown) provided in the bottom of the carrier storage portion 212K, which is loaded in the K.

Next, the developer accommodating container 21K is loaded, and when the replenishing motor is rotated again in response to a command from the control unit 201 in response to a loading signal from a loading button provided on the operation unit 205, the developer accommodating container 21K Toner supply roller 21
By the rotation of 3K, the unused toner is poured from the toner storage portion 211K into the developing device 13K, and is agitated and mixed with the carrier. When the toner concentration detected by the toner concentration detection sensor 139K reaches the toner concentration reference value set for each color stored in the ROM 204 of the control unit 201, in this case, the toner concentration reference value of the black two-component developer. In response to a command from the control unit 201, the rotations of the developing device drive motor and the replenishment motor are stopped, and the copy enable signal of the operation unit 205 is turned on, so that the color image forming apparatus is ready for copying.

After the unused two-component developer is loaded,
During normal copying while the two-component developer reaches the value of the number of times of use, the replenishment motor is rotated and driven according to the toner concentration detected by the toner concentration detection sensor 139, and the toner replenishment roller 213K is rotated. Then, the toner is replenished.

Therefore, the two-component developer for each color of the developing devices 13Y, 13M, 13C and 13K is always used in a state without deterioration, and a good color can be obtained without changing the color balance of the formed color image. An image is obtained.

Here, the toner in the carrier storage container 510K may be mixed in advance with the carrier to prepare a developer having a predetermined toner concentration. In this case, the previous toner density adjustment step can be omitted.

Second Embodiment of Supply of Developer of the Present Invention FIG.
And FIG. 8 will be described. FIG. 7 is a diagram showing a second embodiment of the developer supply mechanism and control, and FIG.
FIG. 3 is a schematic view showing the developer storage container of FIG. The developing device is similar to that of the embodiment described in FIG.

The developer storage container 610K is partitioned by intermediate plates 215K and 216K which are partition members, and a toner storage portion 211K in which black toner is stored in the upper portion and a carrier storage portion 212K in which a carrier is stored in the lower portion. Is provided, and a toner replenishing roller 213K is provided between the intermediate plates 215K and 216K. Toner supply roller 21
Both ends of 3K are rotatably supported by the side wall of the developer storage container 610K and rotated by a gear 214K provided on one side.
The supply opening 217K at the bottom of the developer storage container 610K is sealed by the seal member 218K with the carrier loaded. After the toner is loaded from the top, the top is sealed.

The control unit 201 provided in the main body of the color image forming apparatus includes a CPU 202 and a non-volatile RAM 203.
And the ROM 204, and receives an input signal from the operation unit 205 or various sensors, for example, a signal from the toner concentration detection sensor 139K provided in the developing device 13K, and outputs the output unit 206 such as image forming process control or a counter of the apparatus main body. Performs on / off control of control devices such as motors, clutches and solenoids.

A color image is formed by a copy signal from a copy button from the operation unit 205. At that time, the cumulative value of the number of copies for each color used for color image formation, that is, the developing device for each color is used. Use frequency value is non-volatile RAM
It is stored in 203. The value of the frequency of use of the developing device is stored in the ROM
Each developing device 13Y, 13 for each color stored in 204
Use life of the two-component developer of M, 13C and 13K,
In the present embodiment, for example, when the value of the frequency of use of the black developing device 13K reaches the value of the number of times of use of the black two-component developer, the control unit 201 sends a developer replacement signal to the operation unit 20.
5, a developer exchange signal provided on the operation unit 205, such as a lamp or a liquid crystal display, is turned on.
At this time, the copy function of the apparatus body is stopped. This lighting timing is preferably when the toner in the developer storage container 610K is empty.

A user or a service person removes the used developer storage container 610K from the main body of the apparatus and mounts an unused developer storage container 610K on the developing device 13K. With the seal member 218K removed, the developing device drive motor and the replenishment motor are rotated and driven in response to a command from the control unit 201 in response to a loading signal from a loading button provided on the operation unit 205. A developing sleeve 131K, a supply roller 135K, stirring screws 136K and 137K, and a developer collecting screw 13 provided on the developing device 13K by driving a developing device driving motor (not shown).
Each 8K is rotated. Further, the toner replenishing roller 213K is rotated by the driving of the gear 214K by the rotation of the replenishing motor (not shown).

An unused carrier is poured from the carrier storage portion 212K of the developer storage container 610K into the developing device 13K, and the used two-component developer is discharged from the developing device 13K as described in the above embodiment. To be done. All unused carriers in the carrier storage 212K are developing devices 13K.
Even after being loaded inside, the unused toner is poured from the toner storage portion 211K into the developing device 13K by the rotation of the toner supply roller 213K, and is agitated and mixed with the carrier. When the toner concentration detected by the toner concentration detection sensor 139K reaches the toner concentration reference value set for each color stored in the ROM 204 of the control unit 201, in this case, the toner concentration reference value of the black two-component developer. , Control unit 201
In response to this command, the rotations of the developing device drive motor and the replenishment motor are stopped, the copy enable signal of the operation unit 205 is turned on, and the color image forming apparatus is set to the copy ready state.

After the unused two-component developer is loaded,
During normal copying while the two-component developer reaches the value of the number of times of use, the replenishment motor is rotated and driven according to the toner concentration detected by the toner concentration detection sensor 139, and the toner replenishment roller 213K is rotated. Then, the toner is replenished.

Therefore, the two-component developer for each color of the developing devices 13Y, 13M, 13C and 13K is always used in a state without deterioration, and the color balance of the formed color image does not change and good color is obtained. An image is obtained.

Here, it is also possible to mix the toner in advance with the carrier in the developer storage container to prepare a developer having a predetermined toner concentration. In this case, the step of adjusting the toner density is unnecessary.

FIG. 9 shows a third embodiment of the developer supply according to the present invention.
Also, description will be made with reference to FIG. FIG. 9 is a diagram showing a third embodiment of the developer supply mechanism and control, and FIG.
It is a schematic diagram which shows the developer storage container of FIG. The developing device is similar to that of the embodiment described in FIG.

The developer storage container 410K is partitioned by a seal 419K which is a partition member, and is provided with a carrier storage portion 212K for storing a carrier in the upper portion and a toner storage portion 211K for storing black toner in the lower portion.
The developer replenishing roller 4 is sandwiched between the bottom plates 415K and 416K.
13K is provided. Both ends of the developer supply roller 413K are rotatably supported by the side wall of the developer storage container 410K and rotated by a gear 214K provided on one side. The supply opening 217K at the bottom of the developer storage container 410K is sealed by the seal member 218K. The upper part is sealed while the toner and the carrier are loaded with the seal 419K, which is a partition member, interposed therebetween.

The control unit 201 provided in the main body of the color image forming apparatus includes a CPU 202 and a non-volatile RAM 203.
And a ROM 204, and various sensors such as an input signal from the operation unit 205 or various sensors such as a toner concentration detection sensor 139K provided in the developing device 13K and a developer storage container 410K.
In response to a signal from the remaining amount detection sensor 420K provided in the output section 206, the output section 206 controls the image forming process or the on / off control of the control device such as the counter of the apparatus main body, various motors, clutches and solenoids.

In using the color image forming apparatus, the developer storage container 41 is set by the user or a service person.
Although 0K is mounted on the upper part of the developing device 13K, the seal 419K which is a partition member is pulled out in advance, the developer storage container 410K is shaken to mix the toner and the carrier therein well, and A seal that covers the supply opening 217K at the bottom of the developer storage container 410K in a state where it is an unused two-component developer having a constant toner concentration set slightly higher than the upper limit reference value of the toner concentration of the two-component developer. The member 218K is peeled off and the developing device 13K is mounted.

The developing unit drive motor and the replenishment motor are rotated and driven in response to a command from the control unit 201 in response to a loading signal from a loading button provided on the operation unit 205. The developer replenishing roller 413K is rotated by the driving of the gear 214K by the rotation of the replenishing motor (not shown), and the unused two-component developer is fed into the developing device 13K. Further, a developing sleeve 131K provided on the developing device 13K, a supply roller 135K, stirring screws 136K and 137K, and a developer collecting screw 13 are driven by a developing device driving motor (not shown).
8K is rotated and unused two-component developer is loaded in the developing device 13K so as to be developed. After a certain period of time, the charging of the unused two-component developer into the developing device 13K is completed,
In response to a command from the control unit 201, the rotations of the developing device drive motor and the replenishment motor are stopped, and the copy enable signal of the operation unit 205 is turned on to make the color image forming apparatus ready for copying.

A color image is formed by a copy signal from the copy button from the operation unit 205. At that time, the toner consumed differs due to the difference in the copy for each color used for color image formation. Developing device 13Y, 1
The toner density of 3M, 13C and 13K changes.
In this embodiment, when the toner density detected by the toner density detection sensor 139K provided in the black developing device 13K reaches the toner density lower limit reference value stored in the ROM 204 of the control unit 201, the control unit 201 operates. In response to the instruction, the developing device drive motor and the replenishment motor are rotated to supply the unused two-component developer from the developer storage container 410K into the developing device 13K, and the used two-component developer is used as described in the above embodiment. The two-component developer is discharged from the developing device 13K.

When the toner concentration detected by the toner concentration detection sensor 139K reaches the toner concentration upper limit reference value stored in the ROM 204 of the control unit 201, the control unit 201 receives a command to receive the developing unit drive motor and the replenishment motor. Rotation is stopped.

When the remaining amount detection sensor 420K provided in the developer storage container 410K detects that the unused two-component developer in the developer storage container 410K has become empty, the controller 201 causes the developer to be discharged. An exchange signal is output to the operation unit 205, and a developer exchange signal provided on the operation unit 205, for example, a lamp or a liquid crystal display is turned on. At this time, the copy function of the apparatus body is stopped. The lighting timing is preferably when the two-component developer in the developer container is empty.

The user or service person removes the used developer storage container 410K from the main body of the apparatus, and the developer storage container 21K storing only the unused toner is placed on the upper part of the developing device 13K as described above. When mounted, the copy enable signal of the operation unit 205 is turned on, and the color image forming apparatus is ready for copying.

Therefore, as described above, the developing devices 13Y, 13
The two-component developer for each color of M, 13C and 13K is always used without deterioration, and a good color image can be obtained without changing the color balance of the formed color image.

The developer storage container 410K was used by being replaced according to the life of the developer, unlike the developer storage container 21K containing only toner. However, as shown in the embodiment shown in FIGS. By using the developer storage containers 610K and 410K that store both the toner and the carrier and changing the developer storage container each time the toner becomes empty to supply the carrier, the handling is easy. Become.

FIG. 11 shows an example of application of the present invention to another color image forming apparatus, in which members having the same functions and structures as those described in FIG. 1 are designated by the same reference numerals.

In FIG. 11A, a photoreceptor belt 10a is used as an image forming body, and a latent image is formed by one exposure optical system 12a and one scorotron charger 11a (not shown). Rotate the formed body multiple times to charge each color,
FIG. 11B shows a color image forming apparatus that forms a color image by repeating image exposure and development, and is equipped with the same number of photoconductors, chargers, and developing devices as the colors that need image formation. It is applied to a color image forming apparatus that forms a single color toner image on a transfer body or the like to form a color image.
M, 21C, 21K, developing units 13Y, 13M, 13C,
13K and the developer recovery container 31 have the same function and structure as described in the above embodiment. In the case of FIG. 11 (A),
It is also possible to use a color image forming apparatus using the transfer drum 51 indicated by the one-dot chain line.

[0068]

According to the first to third aspects of the present invention, by collecting all the used two-component developer and the waste toner from a plurality of developing devices in one place, it is possible to improve the efficiency of maintenance by reducing the number of discards. Provided is a color image forming apparatus in which the amount of collected waste toner and the amount of collected developer are proportional to the amount of toner consumed, so that the size of the recovery container is reduced, and hence the size of the main body of the color image forming apparatus is reduced.

According to the present invention, the deteriorated developer and waste toner of the two-component developer used in the plurality of developing devices used in the color image forming apparatus can be efficiently exchanged and collected, Unused toner and two-component developer are supplied to prevent uneven development of the two-component developer due to difference in usage frequency of multiple developers for each color and color difference due to difference in toner concentration to develop. Two-component developer for each color used in the container,
It has become possible to provide a color image forming apparatus which is always used in a state without deterioration and which can obtain a good color image without changing the color balance of the formed color image.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus showing an embodiment of the present invention.

FIG. 2 is a main part diagram showing an example of developer recovery.

FIG. 3 is a view showing a cross section of a developing device.

FIG. 4 is a principal part diagram showing another embodiment of developer recovery.

FIG. 5 is a diagram illustrating an example of a mechanism and control of developer supply.

FIG. 6 is a schematic view showing a carrier storage container and a developer storage container of FIG.

FIG. 7 is a diagram showing a second embodiment of a developer supply mechanism and control.

FIG. 8 is a schematic diagram showing the developer storage container of FIG. 7.

FIG. 9 is a diagram showing a third embodiment of a developer supply mechanism and control.

FIG. 10 is a schematic view showing the developer storage container of FIG.

FIG. 11 is a diagram showing an application example of the present invention to another color image forming apparatus.

[Explanation of symbols]

10 Photoreceptor Drums 13Y, 13M, 13C, 13K Developing Device 19 Cleaning Device 19d Toner Conveying Pipe 21Y, 21M, 21C, 21K Developer Storage Container 31, 32 Developer Recovery Container 138Y, 138M, 138C, 138K Developer Recovery Screw 141Y , 141M, 141C, 141K developer transport pipe 311 waste toner recovery unit 312 developer recovery unit 410Y, 410M, 410C, 410K, 610Y,
610M, 610C, 610K developer storage container 510Y, 510M, 510C, 510K carrier storage container

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display location G03G 15/09 G03G 15/09 Z 21/10 21/00 326

Claims (6)

[Claims] 1. A color image forming apparatus comprising: a plurality of developing devices using a two-component developer composed of toner and carrier; and a cleaning device for cleaning residual toner on an image forming body, each of the plurality of developing devices. A color image forming apparatus comprising: a developer recovery container for recovering used two-component developer discharged further and waste toner discharged from the cleaning device. 2. A used two-component developer is discharged from the developing device according to the number of times each of the two-component developer of the plurality of developing devices is used, and an unused carrier is supplied to the corresponding developing device. The color image forming apparatus according to claim 1, wherein the color image forming apparatus is a color image forming apparatus. 3. A used two-component developer is discharged from the developing device in accordance with toner supply to each of the plurality of developing devices, and an unused carrier is supplied to the corresponding developing device. The color image forming apparatus according to claim 1. 4. A plurality of developing devices using a two-component developer composed of toner and carrier, and a developer recovery container for recovering used two-component developer discharged from each of the plurality of developing devices. In the color image forming apparatus, a carrier storage container for storing a carrier and a developer storage container for supplying toner to each of the developing devices are provided, and the carrier storage container and the developer storage container can be exchanged with each other. According to the predetermined number of times each of the two-component developer stored in the plurality of developing devices is provided, the used two-component developer is discharged from the developing device to the developer recovery container,
An unused carrier is supplied from the carrier storage container to the corresponding developing device, and at the time of copying, unused toner is supplied from the developer storage container to the corresponding developing device. Forming equipment. 5. A plurality of developing devices using a two-component developer composed of toner and a carrier, and a developer collecting container for collecting the used two-component developer discharged from each of the plurality of developing devices. In the color image forming apparatus, each developer storage container in which toner and carrier are separately stored is detachably provided in each of the developing units, and used two-component developer is developed by the developing unit. By being discharged into the agent recovery container, unused developer is supplied from the developer storage container to the corresponding developing device, and at the time of copying, the unused toner from the developer storage container corresponds to the unused toner. A color image forming apparatus characterized by being supplied to a developing device. 6. The color image forming apparatus according to claim 5, wherein an unused carrier is supplied to the developing device before the toner is supplied from the developer storage container.