JPH10282754A - Color electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color electrophotographic device capable of recycling toner without complicating the device nor causing developing trouble due to the color mixture of toner or the mixture of paper powder even if the toner recovered by a cleaner part is used for development again. SOLUTION: This color electrophotographic device is provided with a group of rotatable image forming units 14 constituted by annularly arranging plural image forming units 13 (13K, 13Y, 13M and 13C) having a developing part 23 (23K and 23Y), an electrifier 21, a photoreceptor 20 and a cleaner part 24K for every specified color; an exposure device 25 exposing the photoreceptor 20 in the unit 13 situated at a predetermined position 18; and an image synthesis and transfer part 4 forming a color image on a transfer body 5 by bringing the transfer body 5 into contact with the photoreceptor 20 situated at the predetermined position 18. Then, the developing part 23 and the cleaner part 24K are coupled so that the toner accumulated in the cleaner part 24K can be transferred to the developing part 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a color printer,
The present invention relates to a color electrophotographic apparatus applicable to a color copying machine, a color facsimile, and the like.

[0002]

2. Description of the Related Art The configuration of a conventional color electrophotographic apparatus will be described with reference to Japanese Patent Application Laid-Open No. 8-234514. FIG. 6 is an overall configuration diagram of a color electrophotographic apparatus according to the related art, and is a color electrophotographic apparatus having a maximum print size of A4 size.

In a conventional color electrophotographic apparatus (hereinafter simply referred to as "apparatus"), a transfer drum 100 is used as an image synthesizing transfer section. The paper (not shown) sent from the paper supply unit 101 is wound around the transfer drum 100. Then, the color toner image is transferred onto the paper in a superimposed manner, and a full-color image is formed.

On the left side inside the apparatus, a developing unit rotary section 103 is arranged. Developing device rotary section 103
Are black (K), yellow (Y), magenta (M),
Four sets of developing units 102K, 102Y, 102M, 102C of the same size for each color containing toner of each color of cyan (C)
Are arranged in an annular shape. When the respective developing devices 102 are properly mounted in the apparatus, the mechanical drive system and the electric circuit system of the developing device 102 side, the transfer drum 100 side, and other parts of the apparatus are mutually coupled. They are connected via a ring member and mechanically and electrically integrated. Developing device 102K arranged in an annular shape,
102Y, 102M, and 102C are supported by a support, are driven by a moving motor as a whole, and are configured to be rotatable about a shaft 104.

When the image forming process is started, the photosensitive member 105
Is the laser signal light 1 emitted from the laser exposure device 106
07, an electrostatic latent image is formed on the photoconductor 105. The developing device 102 is sequentially arranged at a position facing the photoconductor 105 by rotational movement to perform development. First, development is performed by the black developing device 102K. The toner image formed on the photoconductor 105 is transferred to the paper wound around the transfer drum 100. Thereafter, the transfer residual toner remaining on the photoconductor 105 is cleaned by the cleaner 108 and stored in the waste toner reservoir 109. Further charge exposure,
An electrostatic latent image of the next color is formed, and the development is performed by switching to the yellow developing device 102Y. Similarly, image formation is performed for magenta and cyan. After the full-color image is formed on the paper, the paper is separated from the transfer drum 100, and the full-color image formed on the paper is fixed by the fixing device 110.

[0006]

However, in the above-described color electrophotographic apparatus according to the prior art, after the photoreceptor is developed by a developing device of each color and transferred to paper on a transfer drum, transfer residual toner (hereinafter referred to as "transfer residual toner"). Waste toner) is cleaned with a cleaner and the waste toner is collected in a waste toner reservoir common to the four colors, so that the waste toner collected in the waste toner reservoir is mixed with four color toners. The waste toner could not be used again for color development.

Further, in a color electrophotographic apparatus according to the prior art, the surface of the paper is in direct contact with the photoreceptor due to the method of winding the paper around the transfer drum. That is, when the toner image is transferred from the photoconductor to the paper on the transfer drum, the paper dust moves to the photoconductor side, and the paper dust is mixed into the waste toner reservoir. However, even if an attempt was made to use the toner mixed with the black toner, image formation was difficult due to the mixed paper dust. Specifically, there is a problem that clogging due to paper powder occurs inside the developing section, causing white streaks and black streaks, and that talc or kaolin, which is a filler of paper, causes abnormal triboelectric charging of the one-component toner. Occurred.

Further, in the color electrophotographic apparatus according to the prior art, since the cleaner section is fixed to the apparatus main body side, the waste toner collected by the cleaner section is returned to the developing section and reused in the image forming unit. Therefore, a transport mechanism for newly transporting the waste toner from the cleaner section to the developing section is required.

The present invention has been made in order to solve such a problem. Even if the toner collected in the cleaner portion is used again for development, a trouble of development due to toner color mixing or mixing of paper dust occurs. It is an object of the present invention to provide a color electrophotographic apparatus capable of recycling toner without using the apparatus and without complicating the apparatus.

[0010]

In order to achieve the above object, a color electrophotographic apparatus according to the present invention comprises a plurality of image forming units each having a developing section, a charger, a photosensitive member, and a cleaner section for each predetermined color. A rotatable image forming unit group arranged side by side in an annular shape, an exposure device for exposing the photoconductor of the image forming unit at a predetermined position, and a transfer body contacting the photoconductor at the predetermined position. A color electrophotographic apparatus comprising: an image synthesis transfer unit that forms a color image on the transfer body, wherein the developing unit is configured to move the toner accumulated in the cleaner unit to the developing unit. And a cleaner unit connected to the cleaner unit.
According to the color electrophotographic apparatus of the present invention, the waste toner is collected for each color in the cleaner section, and the waste toner is configured to move to the developing section of each image forming unit. The waste toner is sent to the developing unit without being mixed. Therefore, this waste toner can be used again for color development.

Further, in the color electrophotographic apparatus according to the present invention, the transfer member constituting the image synthesizing transfer unit is brought into contact with the photosensitive member at the predetermined position, so that each of the photosensitive members is contacted. After sequentially transferring the toner images of each color formed on the transfer body to form a color image on which the toner images of each color are superimposed on the transfer body, the color images are collectively transferred from the transfer body to paper. Is preferably performed. According to this preferred example, when the color image is transferred to the paper, the photoconductor and the paper do not come into contact with each other, so that the paper powder does not move to the photoconductor, and waste toner is removed from the photoconductor. Even if collected, the paper powder does not mix in the waste toner. Therefore, even when the waste toner is used again for color development, image deterioration and abnormal triboelectric charging do not occur.

Further, in the color electrophotographic apparatus according to the present invention, by rotating the image forming unit group, the developing unit and the developing unit are moved so that the toner accumulated in the cleaner unit can be moved to the developing unit. It is preferable that the cleaner unit is connected to the cleaner unit. According to this preferred example, the waste toner can be transported from the cleaner section to the developing section without providing a transport mechanism such as a screw, that is, without complicating the apparatus. The cost can be reduced, and the maintenance of the device becomes easy.

In the color electrophotographic apparatus according to the present invention, when the rotation direction of the image forming unit group reaches the predetermined position, the toner is accumulated in the developing unit. It is preferable that the direction be the state. According to this preferred example, since the toner is appropriately collected in the developing unit at the predetermined position where the image is formed, the waste toner can be reused without any trouble.

In the color electrophotographic apparatus according to the present invention, the rotation direction of the image forming unit group at the time of switching the image forming units is in the direction from the photosensitive member of each of the image forming units to the developing section. Preferably, there is.
According to this preferred example, since the waste toner can be appropriately moved to the developing section, the waste toner can be reused.

Further, in the color electrophotographic apparatus according to the present invention, the predetermined colors are yellow, cyan, magenta,
Preferably, black is included. According to this preferred example, a good color image can be formed by using the above four colors.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a color electrophotographic apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a configuration diagram of a color electrophotographic apparatus according to an embodiment of the present invention. The color electrophotographic apparatus (hereinafter, also referred to as “apparatus”) shown in FIG. 1 has a configuration in which an intermediate transfer belt unit 4 is used as an image combining and transferring unit. The intermediate transfer belt unit 4 includes an intermediate transfer belt 5, a first transfer roller 6, a second transfer roller 7, a driving roller 8, a belt cleaner 9, a belt waste toner reservoir 10, a waste toner full detector 11, and a position detector 1.
2 is used. Intermediate transfer belt unit 4
The details of the configuration will be described later with reference to FIG.

A color electrophotographic apparatus 1 is an outer casing of the apparatus, and the right side of the drawing is the front of the apparatus. Reference numeral 2 denotes a printer front plate. The front plate 2 can be freely opened and closed and raised and closed with respect to a hinge shaft 3 on the lower side of the outer casing 1. Further, maintenance of the apparatus such as attachment and detachment of the intermediate transfer belt unit 4 and paper jams are performed by lowering and opening the front plate 2 to largely release the inside of the apparatus. This intermediate transfer belt unit 4
Is designed to be in a direction perpendicular to the rotation axis generatrix direction of the photoconductor 20, that is, in the direction of the front plate 2.

Black (K),
Four substantially fan-shaped image forming units 13K, 13Y for each color of yellow (Y), magenta (M), and cyan (C)
13M and 13C constitute an image forming unit group 14, and FIG.
As shown in FIG. Each image forming unit 13 is configured to be detachable at a predetermined position of the image forming unit group 14 by opening the top plate 15 of FIG. When the image forming unit 13 is properly mounted at a predetermined position in the apparatus, the mechanical drive system and the electric drive between the image forming unit 13 side, the intermediate transfer belt unit 4 side, and the other parts of the apparatus. The circuit system is coupled via a mutual coupling member (not shown) and mechanically and electrically integrated.

Image forming unit 1 arranged in an annular shape
3K, 13Y, 13M, and 13C are supported by a support (not shown), and are driven by a moving motor 16 as a moving unit as a whole of the image forming unit group 14, and are fixed around a cylindrical shaft 17 that is fixed and does not rotate. It is configured to be rotatable. During image formation, each image forming unit 13 may be sequentially positioned at an image forming position 18 facing a transfer position between the driving roller 8 supporting the above-described intermediate transfer belt 5 and the first transfer roller 6 by rotational movement. it can. The image forming position 18 is also an exposure position with the laser signal light 19, and the image forming unit 13 performs an image forming operation only at this position, and does not operate at other positions.

Each of the image forming units 13 includes a photosensitive member 20, a roller charger 21 for charging the photosensitive member 20, an optical path hole 22 as an opening through which the laser signal light 19 enters the image forming unit 13, and an image forming unit. The developing unit 23 and the cleaner unit 24 for collecting transfer residual toner are used. The photoconductor 20 is formed using, for example, an organic material.

A laser exposure device 25 is provided at the lower right side of the device, and includes a semiconductor laser (not shown),
It comprises a scanner motor 26, a polygon mirror 27, a unit internal mirror 28, a lens system 29 and the like.
The laser signal light 19 corresponding to the time-series electrical pixel signal of the image information emitted from the laser exposure device 25 is formed between the cleaner unit 24K of the image forming unit 13K and the developing unit 23Y of the yellow image forming unit 13Y. Light path 30
Passes through a window opened in a part of the shaft 17 and enters a mirror 31 fixed in the shaft 17. Thereafter, the laser signal light 19 is reflected by the mirror 31, enters the image forming unit 13K from the optical path hole 22 of the image forming unit 13K at the image forming position 18, and is disposed vertically in the image forming unit. After passing between the developing unit 23K and the roller charger 21, the light finally enters the exposure unit on the left side surface of the photoconductor 20, and is scanned and exposed in the generatrix direction.

Here, since the optical path 30 utilizes a gap in the wall surface between the black image forming unit 13K and the yellow image forming unit 13Y, the image forming unit group 14 has almost no wasted space. There is no. Further, since the mirror 31 is provided at the center of the image forming unit group 14, it can be constituted by a single fixed mirror, and a simple and easy-to-align device can be constituted. .

A feeding roller 32 is provided inside the front plate 2 constituting the apparatus. The sheet transport path is formed so that the sheet 34 is sent to a nip portion between the intermediate transfer belt 5 and the third transfer roller 33 on the second transfer roller 7. A fixing device 35 is provided at an upper portion inside the apparatus.

FIG. 2 is a diagram showing the configuration of the black image forming unit 13K constituting the color electrophotographic apparatus according to the present embodiment. Each image forming unit 13
Only the color of the toner put inside is different, and each is constituted by the same constituent member. Therefore, here, in order to simplify the explanation, the image forming unit 13K for black is used.
And only the other colors will be omitted. In addition,
The same reference numerals are assigned to the same parts for each color, and when it is necessary to distinguish the configuration of each color, letters (K, Y, M, C) indicating each color are added to the reference numerals.

As shown in FIG. 2, the image forming unit 13
Is composed of a photoconductor 20, a roller charger 21 made of conductive rubber for negatively charging the photoconductor 20, a developing unit 23, and a cleaner unit 24 for collecting untransferred toner. The photoreceptor 20 is an organic photoreceptor mainly composed of a polycarbonate-based binder resin using phthalocyanine as a photosensitive material. The developing unit 23 includes a conductive rubber developing roller 38, a sponge supply roller 39, a metal doctor roller 40, a metal scraper 41, and the like. Further, inside the toner hopper 36, a negatively chargeable black toner 37K in which a black pigment is dispersed in a polyester resin is contained. Also,
The laser signal light 19 is configured to reach an image forming position through an optical path hole 22 provided in the image forming unit 13.

The developing unit 23 will be described in more detail. As shown in FIG. 2, the toner 42 is accumulated near the developing roller 38 made of conductive rubber and the supply roller 39 made of sponge. The toner 42 is supplied to the supply roller 3
9 to supply the toner to the surface of the developing roller 38 to develop the photoconductor 20. The supply roller 39 applies the toner 42 to the developing roller 3.
In addition to supplying the toner 42 to the developing roller 38, the toner 42 has a function of frictionally charging the toner, a function of scraping off the toner 42 already adhered on the developing roller 38, a function of preventing the toner 42 on the developing roller 38 from being overcharged, and a function of removing electricity. It has the function of

The image forming unit 13 includes a high voltage power supply 43 for applying a voltage to the developing roller 38, a high voltage power supply 44 for applying a voltage to the doctor roller 40, and a high voltage power supply 45 for applying a voltage to the roller charger 21. Have been.

The cleaner portion 24 for cleaning the toner remaining on the surface of the photoreceptor 20 after the transfer is constituted by using a rubber cleaning blade 46 or the like. Toner hopper 36
Is connected to the cleaner unit 24, the toner 42 of the developing unit 23 is transferred to the cleaner unit 24, the toner 47 collected by the cleaner unit 24 is transferred to the developing unit, and the toner is transferred between the developing unit 23 and the cleaner unit 24. The image forming unit 13 according to the present embodiment is configured to freely move back and forth.

Here, for example, the diameter of the photosensitive member 20 is set to 30.
mm in the direction of the arrow T at a peripheral speed of 100 mm / s, the diameter of the developing roller 38 is 18 mm, the direction of the arrow S is 160 mm / s, and the diameter of the doctor roller 40 is 12 mm in the direction of the arrow U at a peripheral speed of 80 mm / s. I will make it.

FIG. 3 is a configuration diagram showing the vicinity of the intermediate transfer belt unit constituting the color electrophotographic apparatus according to the present embodiment. The intermediate transfer belt unit 4
As shown in FIG. 3, the unit case 48, the transfer belt 5, the first transfer roller 6, the second transfer roller 7, the driving roller 8, the belt cleaner 9, the belt waste toner reservoir 10, and the belt cleaner 9 store the belt waste toner. A pipe 49 for sending waste toner to the apparatus 10, a contact / disengagement cam 50 installed in the apparatus main body for separating and contacting the belt cleaner 9 from the intermediate transfer belt 5, a waste toner full detector 11, a position detector 12 for detecting a belt tip, and the like. It is configured. The high voltage power supply 51 is connected to the first transfer roller 6, and the second transfer roller 7 and the drive roller 8 are grounded.

The intermediate transfer belt 5 has a thickness of, for example, 100
Endless belt-like semi-conductivity of about μm (medium resistance, volume resistivity 1 × 10 ⁸ to 10 ¹² Ω · cm, surface resistivity 1 ×
10 ⁸ to 10 ¹¹ Ω [JIS K6911]) polycarbonate film as a base material and PFA / PT as a surface layer
Using fluororesin such as FE, 100-500μ
It is composed of a film having a thickness of about m. The intermediate transfer belt 5 is wound around the first transfer roller 6, the second transfer roller 7, and the drive roller 8, and is configured to be movable in the direction of arrow R.

The circumferential length of the intermediate transfer belt 5 is A
In order to perform full color printing on paper smaller than 4 or letter size, the length in the longitudinal direction (297 mm) of A4 image receiving paper, which is the maximum size, is slightly longer than half the circumference of the photosensitive drum (diameter 30 mm). (80mm)
377 mm. That is, the photoconductor 2
The length is set to exactly four times the circumference of 94 (94 mm).

The moving speed of the intermediate transfer belt 5 is 1.5% faster than the image forming speed of the image forming unit 13 (100 mm / s equal to the peripheral speed of the photosensitive member) in order to prevent the hollow transfer of the toner image. It is set as follows. Further, the intermediate transfer belt 5 is configured to be stationary during the rotational movement operation of the image forming unit group 14.

The belt cleaner 9 is configured to clean toner remaining on the intermediate transfer belt 5. During the formation of the color image on the intermediate transfer belt 5, the belt cleaner 9 is moved away from the intermediate transfer belt 5 by the separation / contact cam 50 so as not to scratch the toner image on the intermediate transfer belt 5. It is configured to wait.

A third transfer roller 33 provided in the apparatus main body is disposed at a portion facing the second transfer roller 7. When transferring the toner image to the paper 34, the paper 34 is brought into contact with the intermediate transfer belt 5 using the third transfer roller 33 and the second transfer roller 7 while applying a transfer voltage to the third transfer roller 33 by the power supply 52. Let it. The third transfer roller 33 is configured to rotate 1.5% slower than the intermediate transfer belt 5 in order to prevent a dropout phenomenon when a toner image is transferred onto paper.

When transferring the toner image on the photosensitive member 20 to the intermediate transfer belt 5, the high voltage power supply 5
1, a voltage of about +1.0 kV (100 μA) is applied. At this time, the photosensitive member 20 is opposed to the first transfer roller 6.
When the toner image is transferred from the photoconductor 20 to the intermediate transfer belt 5 by bringing the intermediate transfer belt 5 into direct contact with the intermediate transfer belt 5, a so-called “front jump” phenomenon occurs before the intermediate transfer belt 5 comes into contact with the photoconductor, and the image is disturbed. In addition, it becomes difficult to uniformly adjust the contact pressure between the first transfer roller 6 and the photoconductor 20. However, in the present embodiment, these problems occur because the intermediate transfer belt 5 stretched between the two rollers of the first transfer roller 6 and the driving roller 8 is brought into contact with the photosensitive drum 20. do not do.

The main configuration of the color electrophotographic apparatus according to the embodiment of the present invention has been described above. Next, a full-color image forming operation in the color electrophotographic apparatus according to the embodiment of the present invention will be described with reference to FIGS.

In this embodiment, first, a black image forming step is performed. When performing the black image forming step, first, the photoconductor 20 constituting the black image forming unit 13 </ b> K shown in FIG. 2 is set to −700 V using the roller charger 21 to which an AC voltage is applied by the power supply 45. Charge. Next, a laser signal light 19 is applied to the photoconductor 20.
To form an electrostatic latent image. At this time, the photoconductor 20
Had an exposure potential of -50V. Next, this photoconductor 20
Is developed by a developing roller 38 carrying a non-magnetic one-component black toner 42K. When the photosensitive member 20 passes through the uncharged area, the developing roller 38 is supplied to the developing roller 38 by the high-voltage power supply 43.
A DC voltage of +100 V is applied. Then, -700V
When passing through the surface of the photoreceptor 20 on which the electrostatic latent image has been written, the high voltage power supply 43 supplies the developing roller 38 with -2.
A DC voltage of 00V is applied. As a result, a black toner image is formed on the photoreceptor 20 where the image is inverted only in the image area.

As shown in FIG. 1, the image forming unit group 14
Is located at the image forming position 18, and at this time, the photosensitive member 20 is attached to the intermediate transfer belt 5.
Is in contact with Then, in the image forming step of the image forming unit described above, an image is formed with the black toner. At this time, the photoconductor 20 is rotated exactly four times, that is, 1440 °.

Immediately after all the black toner images have been transferred to the intermediate transfer belt 5, the entire image forming unit group 14 is driven by the moving motor 16 to move in the direction of arrow Q in FIG.
The image forming unit 13Y rotates by 0 ° and stops at the position where the yellow image forming unit 13Y reaches the image forming position 18. Image forming unit group 1
When the rotation of Step 4 is completed and the yellow image forming unit 13Y reaches the image forming position 18, similarly to the case of black, the laser exposure device 25 irradiates the yellow image forming unit 13Y with the laser signal light 19 using the yellow signal. Then, formation and transfer of a yellow toner image are performed. By this time, the intermediate transfer belt 5 has made one revolution, the timing of writing the yellow signal light is controlled based on the signal from the position detector 12, and the previously transferred black toner image is replaced with the next yellow toner image. Are superimposed so as to coincide in position. During this time, since the third transfer roller 33 is retracted to a position where the third transfer roller 33 is not in contact with the intermediate transfer belt 5, the third transfer roller 33 does not disturb the toner image on the transfer belt 5.

After the yellow toner image has been transferred to the intermediate transfer belt 5, the image forming unit group 14 is again driven by the moving motor 16 to rotate 90 ° in the direction of arrow Q, and the magenta image forming unit 13M It stops at the position where it has reached the image forming position 18. Then, the same operation as that of black and yellow is performed for the magenta image forming unit 13M.

After the transfer of the magenta toner image onto the intermediate transfer belt 5, the entire image forming unit group 14 is further rotated by 90 ° in the direction of arrow Q, and the cyan image forming unit 1 is rotated.
3C is replaced with the image forming position 18. During this switching operation, the sheet 34 starts to move by the feed roller 32 and temporarily waits. Then, image formation using cyan toner is performed by the same operation as the above-described black, yellow, and magenta, and the four color toner images are superimposed on the intermediate transfer belt 5 in a position-matching manner to form a full-color image. You. The timing is adjusted so that the leading position of the cyan image on the intermediate transfer belt 5 comes to the opposing portion of the second transfer roller 7 and the third transfer roller 33, and the third transfer roller 33 is set to +3 kV.
, And the toner images of four colors are collectively transferred to the paper 34. The toner image transferred to the paper 34 is fixed by a fixing device 35.

As described above, in the color electrophotographic apparatus according to the present embodiment, image formation is performed in the order of black, yellow, magenta, and cyan, and a four-color toner image is formed on the sheet 34 sent from the sheet cassette. After batch transfer
The toner image transferred to the paper 34 is fixed by a fixing device 35. Thereafter, the entire image forming unit group 14 is driven by the moving motor 16 to rotate 90 ° in the direction of arrow Q in FIG. 1, and the black image forming unit 13K reaches the image forming position 18 again, and the full-color image is formed. Is completed.

In the above-described embodiment, a specific structure of the image forming unit is used. However, the present invention is not limited to this structure. May be used. Further, in the present embodiment, a one-component contact developing method using a conductive elastic roller is used, but the present invention is not limited to this method. For example, a jumping developing method, an impression developing method, or the like is used. Is also good.

FIG. 4 shows the structure of the image forming unit group 14 constituting the color electrophotographic apparatus according to the present embodiment and the rotation direction of the image forming unit group 14 when toner is recycled. is there. Hereinafter, the recycling use of the toner will be described with reference to FIG.

In this embodiment, as shown in FIG. 4, the developing section 23 and the cleaner section 2 of each image forming unit 13 are used.
4 are connected internally, so that the toner accumulated in the cleaner unit 24 can be moved to the developing unit 23 by the rotational movement of the image forming unit group 14.

Now, first, the image forming unit 13
In the position A of FIG. At this time, a part of the toner is present at a position 53 in the toner hopper 36, and a large part of the toner is present at a position 54 below the image forming unit 13. Next, when the image forming unit group 14 is rotated by 90 ° in the direction of arrow Q and the image forming unit 13 is at the position B, the toner is collected at the position 55. Further, the image forming unit group 14
Is rotated by 90 °, and the image forming unit 13 reaches the position C, the toner is collected at the position 56 near the developing unit.
Further, the image forming unit group 14 is rotated by 90 °,
When the image forming unit 13 finally moves to the position D, that is, the image forming position 18, the toner collects at the position 57 where the toner accumulates in the developing unit 23, and the development can be performed without any trouble.

In the color electrophotographic apparatus according to the present embodiment, an image forming unit group 14 is constituted by using a plurality of image forming units 13 each having a developing unit 23, a photoconductor 20 and a cleaner unit 24 for each color. In each image forming unit 13, since the toner moves as described above, the toner collected by the cleaner unit 24 of each color is collected for each color. You can do it.

Further, in the color electrophotographic apparatus according to the present embodiment, since a color image is once synthesized on the intermediate transfer belt 5 and then collectively transferred onto paper, the photosensitive member 20 of each image forming unit 13 is Does not come into direct contact with the paper. Further, the intermediate transfer belt 5 that comes into contact with the paper is cleaned by the belt cleaner unit, and then the respective image forming units 1 are cleaned.
3 is in contact with the photoreceptor 20, so that no paper dust is mixed into the cleaner portions 24 of the image forming units 13 of each color. Therefore, according to the present embodiment, the toner collected by the cleaner unit 24 of the image forming unit 13 of each color does not have color turbidity and does not include foreign matter such as paper dust. Even if it is returned to 23 and subjected to development, no problem occurs.

Further, in the color electrophotographic apparatus according to the present embodiment, the image forming unit group 14 is composed of a plurality of image forming units 13 each having a developing section 23, a photoconductor 20 and a cleaner section 24 for each color. Then, as the image forming unit group 14 rotates, the toner moves from the cleaner unit 24 to the developing unit 23 as described above. In other words, in the apparatus according to the present embodiment, by making good use of the rotational movement of the image forming unit group 14, the cleaner unit 2 can be manufactured without complicating the structure of the apparatus.
4 can be transported to the developing unit 23. Such a method of moving the toner from the cleaner unit 24 to the developing unit 23 is as follows.
Compared with a transport mechanism using a screw or the like, since stress is not applied to the toner, there is also an advantage that the toner is hardly deteriorated.

FIG. 5 is a view showing a case where the image forming unit group 14 rotates in a direction opposite to that of FIG. In FIG. 5, the image forming unit group 14 rotates in the direction of arrow P. First, assuming that the image forming unit 13 is at the position a, the toner will be at the position 58.
Next, when the image forming unit group 14 rotates 90 ° in the direction of arrow P and the image forming unit 13 reaches the position b, the toner is divided into the positions 59 and 60. Further, when the image forming unit group 14 rotates and the image forming unit 13 comes to the position c, the toner is collected at the position 61. Further, the image forming unit group 14 rotates and finally,
The image forming unit 13 is at the position of d, that is, the image forming position 1
8, the toner collects at the position 62 inside the cleaner section 24, and the developing section 23 completely loses the toner.

That is, in the apparatus according to the present embodiment, when the image forming unit group 14 is rotated in the reverse direction, the waste toner collected by the cleaner unit 24 cannot be supplied to the developing unit 23. Will not be reusable. Therefore, in such an apparatus in which the cleaner unit 24 and the developing unit 23 are connected inside the image forming unit 13 and the waste toner collected by the cleaner unit 24 is reused for development by the developing unit 23, the image forming unit group The rotation direction 14 has an important meaning for smooth toner supply. However, the appropriate rotation direction of the image forming unit group 14 is not limited to the direction according to the present embodiment (the Q direction in FIG. 4), and any appropriate direction depends on the structure of each image forming unit 13. Will be different.
For example, the position b in FIG.
When the image forming unit group 14 is rotated upside down in the direction P in FIG. 5, the waste toner collected by the cleaner unit 24 is
3, it becomes possible to reuse for development.

[0054]

As described above, according to the present invention,
Even if the toner collected in the cleaner part is used again for development,
A color electrophotographic apparatus capable of recycling toner can be obtained without causing a trouble of development due to toner color mixing or mixing of paper powder and without complicating the apparatus.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a color electrophotographic apparatus according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a black image forming unit constituting the color electrophotographic apparatus shown in FIG. 1;

FIG. 3 is a configuration diagram near an intermediate transfer belt unit constituting the color electrophotographic apparatus shown in FIG.

FIG. 4 is a diagram illustrating a configuration of an image forming unit group included in the color electrophotographic apparatus illustrated in FIG. 1 and a rotation direction of the image forming unit group when toner is recycled.

FIG. 5 is a diagram for describing a problem with a rotation direction of an image forming unit group;

FIG. 6 is a configuration diagram of a color electrophotographic apparatus according to the related art.

[Explanation of symbols]

 4 Intermediate Transfer Belt Unit 5 Intermediate Transfer Belt (Transfer Body) 6 First Transfer Roller 7 Second Transfer Roller 9 Belt Cleaner 10 Belt Waste Toner Storage 13 Image Forming Unit 13K Black Image Forming Unit 13Y Yellow Image Forming Unit 13M Magenta Image forming unit 13C Image forming unit for cyan 14 Image forming unit group 18 Image forming position (predetermined position) 19 Laser signal light 20 Photoconductor 21 Roller charger 22 Optical path hole 23 Developing unit 24 Cleaner unit 25 Laser exposure device 31 Mirror 35 Fixing Machine

Claims (6)

[Claims] 1. A rotatable image forming unit group in which a plurality of image forming units each having a developing unit, a charger, a photoconductor, and a cleaner unit for each predetermined color are arranged in an annular shape. An exposure device for exposing the photoreceptor of the image forming unit, and an image synthesizing transfer unit for forming a color image on the transfer body by bringing a transfer body into contact with the photoreceptor at the predetermined position. A color electrophotographic apparatus, wherein the developing unit and the cleaner unit are connected so that toner accumulated in the cleaner unit can move to the developing unit. 2. The method according to claim 1, further comprising: bringing the transfer member forming the image combining transfer unit into contact with the photoconductor at the predetermined position to transfer the toner image of each color formed on each of the photoconductors to the transfer unit. 2. The color electrophotograph according to claim 1, wherein the color images are collectively transferred from the transfer body to paper after a color image formed by superimposing toner images of the respective colors on the transfer body by sequentially transferring the color images onto a body. 3. apparatus. 3. The developing unit and the cleaner unit are connected so that the toner accumulated in the cleaner unit can be moved to the developing unit by rotating the image forming unit group. 3. The color electrophotographic apparatus according to 1 or 2. 4. The image forming unit group according to claim 3, wherein the rotation direction of the image forming unit group is a direction in which the toner is accumulated in the developing unit when the image forming unit reaches the predetermined position. Color electrophotographic equipment. 5. The color electrophotographic apparatus according to claim 3, wherein a rotation direction of the image forming unit group when the image forming units are switched is a direction from the photoconductor of each of the image forming units to the developing unit. . 6. The color electrophotographic apparatus according to claim 1, wherein the predetermined color includes yellow, cyan, magenta, and black.