JPH07110611A - Color electrophotographic apparatus and intermediate transfer belt unit used therefor - Google Patents

Abstract

PURPOSE:To provide an excellent color electrophotographic device whose inter mediate transfer part is compactly and simply constituted and which is excellent in maintainability and an intermediate transfer belt unit used therefor. CONSTITUTION:Plural image forming units 12 composed of a photoreceptor 18 and a developing means having different color toner are used and can be successively moved to the same image forming position 16 by rotating and moving the whole of an image forming unit group 14. In the image forming position, a toner image is transferred from the photoreceptor 18 to an intermediate transfer belt 3. It is utilized together with waste toner reservoirs 9a and 9b to form the intermediate transfer belt unit 2 and freely attached/detached to/from a main body in a direction perpendicular to the rotary shaft of the photoreceptor 18.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color electrophotographic apparatus applicable to a color printer, a color copying machine, a color fax machine and the like, and an intermediate transfer belt unit used therein.

[0002]

2. Description of the Related Art Generally, in order to form a color image by electrophotography, a method of forming a color image by superposing toner images of yellow, magenta, cyan and black on a transfer material is used. This color image is formed by sequentially forming toner images of respective colors on a single photoconductor, rotating a transfer material wound around a transfer drum to repeatedly face the photoconductor, and sequentially forming respective colors on the photoconductor. And a transfer drum method in which the toner images of FIG. A continuous superposition method of transferring and superposing is common.

A color image forming apparatus using the former transfer drum system is disclosed in Japanese Patent Laid-Open No. 252982. FIG. 5 shows an outline of the overall configuration of the conventional example of the transfer drum system, and the configuration and operation will be briefly described below. In FIG. 5, reference numeral 101 denotes a photoconductor, which faces the photoconductor 102, a developing unit 103, a transfer drum 104, and a cleaner 105.
Is provided. The developing unit 103 includes a Y developing device 106 for forming a yellow toner image, an M developing device 107 for magenta color, a C developing device 108 for cyan color, and a Bk developing device 109 for black color. As a result, the entire developing device group rotates and each developing device sequentially faces the photoconductor 101 to be ready for development. During operation, the transfer drum 104 and the photoconductor 101 are opposed to each other and rotate at a constant speed in the arrow direction.

First, when the operation starts, the photosensitive member 101 rotates in the direction of the arrow and the surface thereof is uniformly charged by the charger 102. Then, the surface of the photoconductor 101 is irradiated with a laser beam 110 modulated with a signal for forming a yellow image of the first color to form a latent image. Further, this latent image is first developed by the yellow Y developing device 106 facing the photoconductor to form a yellow toner image.
By the time the formed yellow toner image reaches the position facing the transfer drum 104, one sheet of paper as the transfer material already sent from the paper feeding unit 111 is already on the outer periphery of the transfer drum 104 with the leading end claw portion. The toner image is formed by being caught by 112 and wound, and the toner image is formed at a predetermined timing so that the yellow toner image on the photoconductor faces and meets at a predetermined position.

A yellow toner image on the photoconductor is transferred to a transfer charger.
After the transfer to the sheet by the action of 113, the surface of the photoconductor is cleaned by the cleaner 105 to prepare for the image formation of the next color. Subsequently, magenta, cyan, and black toner images are also formed in the same manner, but at that time, the developing unit 103 makes each developing device used according to the color face the photoconductor to be in a developable state. The diameter of the transfer drum is large enough so that the longest paper can be wound and the developing unit can be exchanged between the images of the respective colors.

In the irradiation of the laser beam 110 for forming the image of each color, the toner image of each color on the photoconductor and the toner image already transferred to the sheet on the transfer drum are aligned and face each other as the toner rotates. It is performed in a timely manner. In this way, the four-color toner images are transferred onto the paper on the transfer drum 104 in an overlapping manner, and a color image is formed on the paper. After the toner images of all colors are transferred, the paper is peeled from the transfer drum 104 by the peeling claw 114, and the conveyance unit 115
After that, the upper toner image is fixed by the fixing device 116 and is discharged to the outside of the apparatus. The above is a brief description of the configuration and operation of the conventional example.

On the other hand, as an example of a color image forming apparatus using a continuous transfer system, there is JP-A-1-250970. In this example, four image forming stations each including a photoconductor, an optical scanning unit, etc. are arranged to form an image of four colors.
The sheets conveyed on the belt pass under the respective photoconductors, and the toner images are superimposed. Furthermore, as another method for forming a color image by superimposing toner images of different colors on a transfer material, toner images of respective colors sequentially formed on a photoconductor are first superposed on an intermediate transfer material, and finally this is formed. A method of collectively transferring to a transfer material is disclosed in JP-A-2-212867.

[0008]

Among the conventional examples as described above, in the transfer drum system, the transfer drum is used in order to superimpose the positions of the toner images of different colors. This transfer drum is rotated at the same speed with respect to the photoconductor, and the timing of the leading edge of the image is adjusted to match the mutual positions of the toner images of the respective colors when a color image is formed. However, in the above-mentioned configuration, since it is necessary to wind the paper around the transfer drum, the diameter of the transfer drum needs to be a certain size or more, and the structure is very complicated, so that the device is large. Was becoming.
Also, strong paper such as postcards and cardboard cannot be used because it cannot be wound around the transfer drum.

On the other hand, the continuous transfer method has an image forming position corresponding to the number of colors, and a transfer drum is not required because it is sufficient to pass the paper one by one therethrough. A plurality of latent image forming means such as a laser optical system for forming a latent image on the upper surface are required corresponding to the number of colors, and the structure is very complicated and expensive. Furthermore, since there are a plurality of image forming positions, the relative positional relationship of the image forming portions of each color has a great influence on the color misregistration. In particular, it is necessary to perform accurate alignment between the colors of the latent image by means of the latent image forming means, and as shown in Japanese Patent Laid-Open No. 250970 / 1-2970, the image exposure system corresponding to the latent image forming means is suitable. There was a problem that a device and a complicated structure were required.

Further, Japanese Patent Application Laid-Open No. 2-21 using an intermediate transfer material
In JP-A-2867, in order to form a toner image of each color on a single photoconductor by each color developing unit, the size of the photoconductor becomes large, and for example, a belt shape in which the photoconductor is difficult to handle is used. Further, it is difficult to maintain each color developing device and the photoconductor. For example, when each developing device is replaced during maintenance, matching adjustment with the characteristics of the photoconductor is required, and when replacing the photoconductor, position adjustment with each developing device is required. In view of the above problems, an object of the present invention is to provide an excellent color electrophotographic apparatus having a small and simple structure of an intermediate transfer portion and good maintainability, and an intermediate transfer belt unit used for the same.

[0011]

In order to achieve the above object, the present invention comprises at least rotating photoconductors and developing means having toners of different colors, and different photoconductors are provided on the photoconductors. A plurality of movable image forming units for forming color toner images, an image forming position composed of a single exposure position and a single transfer position, and an image in which the plurality of image forming units are annularly arranged. An image forming unit group, each of the plurality of image forming units, a moving unit for rotating the entire image forming unit group to sequentially position the single image forming position, an exposure unit for generating signal light, A mirror that is arranged substantially at the center of rotation of the image forming unit group and guides the signal light of the exposing unit to the single exposure position; and an image forming unit that is located at the image forming position. An intermediate transfer belt, which exposes the signal light to an optical member and develops it with toner, transfers the toner image at the single transfer position, and forms color toner images in an overlapping manner; and an intermediate transfer belt on the intermediate transfer member. A color electrophotographic apparatus, comprising: a second transfer unit that transfers a color toner image onto an image receiving sheet; and a fixing unit that fixes the toner image transferred onto the image receiving sheet, the intermediate transfer belt and the intermediate transfer belt. A cleaner that cleans the toner on the transfer belt constitutes an intermediate transfer belt unit, and the direction in which the intermediate transfer belt unit is attached to and detached from the casing of the color electrophotographic apparatus is the direction perpendicular to the rotation axis of the photoconductor of the image forming unit. It is a color electrophotographic apparatus having a configuration.

The present invention further comprises at least rotating photoconductors and developing means having toners of different colors, respectively, and a plurality of movable members forming toner images of different colors on the photoconductors. An image forming unit, an image forming position composed of a single exposure position and a single transfer position, an image forming unit group in which the plurality of image forming units are annularly arranged, and a plurality of image forming units. Moving means for rotatively moving the entire image forming unit group to sequentially position each at the single image forming position, exposing means for generating signal light, and substantially the center of rotation of the image forming unit group. And a mirror that guides the signal light of the exposure unit to the single exposure position and a photoconductor of the image forming unit that is located at the image forming position, and exposes the signal light to the toner. After the development, the toner image is transferred at the single transfer position, and the intermediate transfer belt for forming the color toner images by superposition, the belt cleaner for cleaning the intermediate transfer belt, and the intermediate transfer belt are cleaned. A waste toner reservoir for storing the collected waste toner, a second transfer means for transferring the color toner image on the intermediate transfer body onto an image receiving sheet, and a fixing means for fixing the toner image transferred on the image receiving sheet. A device for use in a color electrophotographic apparatus, comprising: the intermediate transfer belt, a belt cleaner for cleaning toner of the intermediate transfer belt, and the waste toner reservoir, and An intermediate transfer belt unit configured to be attachable to and detachable from the photoconductor of the image forming unit in a direction perpendicular to a rotation axis.

[0013]

The structure of the color electrophotographic apparatus having the means for solving the above problems will be described with reference to FIG. In FIG. 1, reference numeral 1 is an exterior casing of a color electrophotographic printer, and the right end face side in the drawing is the front face. 1A is a printer front plate,
The front plate can be freely opened and closed as shown by a chain double-dashed line and opened and closed as shown by a solid line about the hinge 1B on the lower side of the outer casing 1 of the printer. The operation of attaching / detaching the intermediate transfer belt unit 2 to / from the printer and the inspection / maintenance of the inside of the printer such as a paper jam are performed by tilting the front plate 1A to open the inside of the printer. The attachment / detachment operation of the intermediate transfer belt unit 2 is designed to be perpendicular to the rotation axis of the photoconductor.

The structure of the intermediate transfer belt unit 2 is shown in FIG. The intermediate transfer belt unit 2 includes a unit housing 2a, an intermediate transfer belt 3, and a first conductive elastic member.
Transfer roller 4, second transfer roller made of aluminum roller 5, tension roller 6 for adjusting the tension of intermediate transfer belt 3, cleaning roller 7 for cleaning the toner image remaining on intermediate transfer belt 3, cleaning roller 7
A scraper 8 for scraping off the collected toner on the upper side, waste toner reservoirs 9a and 9b for storing the collected toner, and a position detector 10 for detecting the position of the transfer belt are included in the printer front plate in FIG. 1A can be opened and closed like a chain double-dashed line, and can be freely attached to and detached from a predetermined storage portion in the printer exterior casing 1.

The intermediate transfer belt 3 is made of an endless belt-like film having a thickness of 100 μm and made of semi-conductive urethane as a base material. It is wound around two transfer rollers 5 and is movable in the direction of the arrow. Here, the peripheral length of the intermediate transfer belt 3 is equal to the length (298 mm) in the longitudinal direction of the A4 size paper, which is the maximum size, and the photosensitive drum described later.
The length is set to 350 mm, which is a little longer than half the circumference (diameter 30 mm) (52 mm).

The conductive first transfer roller 4 has a resistance of 107 Ωc.
It has a resistance of m, and when attached to the printer body,
It is pressed against the photoconductor through the intermediate transfer belt 3 with a force of 1.0 kg. A third transfer roller 35 (shown in FIG. 1) having the same configuration as the first transfer roller 4 is lightly pressed against the second transfer roller 5 via the intermediate transfer belt 3 so as to be driven and rotatable. Further, the cleaning roller 7 is a roller of a belt cleaner portion that cleans the intermediate transfer belt 3. This is a configuration in which an AC voltage that electrostatically attracts toner is applied to a metallic roller.

FIG. 3 is a perspective view showing the structure of the position detector 10 provided inside the intermediate transfer belt unit 2. There is a position detection hole 11 at the end of the intermediate transfer belt 3, and the position detector 10 optically detects the passage of the position detection hole 11 to align the color image on the intermediate transfer belt 3. It is a configuration to be performed.

Returning again to FIG. Black in the center of the printer,
Four sets of fan-shaped image forming units 12Bk, 12Y, 12M, and 12C for each color of cyan, magenta, and yellow form an image forming unit group 13 and are arranged in an annular shape as shown in the drawing. Each image forming unit is attachable to and detachable from a predetermined position of the image forming unit group 13 by opening the printer top plate 1C of FIG. 1 around the hinge 1D. The image forming unit 12 is properly installed in the printer so that the mechanical drive system and the electric circuit system on both the image forming unit side and the printer side are connected to each other via a mutual coupling member (not shown). Integrated electrically and electrically.

Image forming unit 12 arranged in an annular shape
Bk, 12C, 12M and 12Y are supported by a support (not shown), and are driven by a moving motor 14 which is a moving means as a whole, and can be rotated about a fixed and non-rotating cylindrical shaft 15. It has become. Each image forming unit can be sequentially located at an image forming position 16 facing the second transfer roller 4 supporting the intermediate transfer belt 3 described above. The image forming position 16 is also an exposure position by the laser signal light 17.

Since each image forming unit is composed of the same constituent members except for the developer to be put therein, the image forming unit 12Bk for black will be described in order to simplify the description.
The other colors are omitted. Note that, for each color, the same portions are denoted by the same reference numerals, and when it is necessary to distinguish the configurations of the respective colors, the letters indicating the respective colors are attached to the reference numerals. Figure 4
The black image forming unit 12Bk is shown in detail in FIG. here,
The inventors have used the developing method disclosed in Japanese Patent Application No. 4-50274, but it goes without saying that any developing method can be used as long as it is used in a normal electrophotographic method. In FIG. 4, 18 is an organic photoconductor in which phthalocyanine is dispersed in a polycarbonate binder resin, 19 is a non-rotating magnet fixed coaxially with the photoconductor 18, 20 is a charging roller for negatively charging the photoconductor 18, and 17 is a laser. Beam scanning light (laser signal light), 21 is an exposure window through which a laser beam enters the image forming unit, and 22 is a developer hopper. The developer hopper 22 is charged with a two-component developer 25Bk in which a ferrite carrier 23Bk having a particle size of 50 μm coated on the surface with a silicone resin and a toner 24Bk in which a black pigment is dispersed in a polyester resin are mixed. 18 Attach to the surface. 26
Is a rotatable collection electrode roller made of aluminum, 27 is a non-rotating magnet fixed coaxially inside thereof, 28 is an AC high voltage power source for applying a voltage to the collection electrode roller 26, and 29 is toner on the collection electrode roller 26. It is a scraper made of scraping polyphenylene sulfide. The diameter of the photoconductor 18 is 30 mm
, Rotate in the direction of the arrow at a peripheral speed of 60 mm / s, and collect the recovery electrode roller.
The 26 had a diameter of 16 mm and was rotated in the direction of the arrow at a peripheral speed of 60 mm / s. Reference numeral 30 is a cleaner for cleaning the toner remaining on the surface of the photoconductor after transfer.

Returning to FIG. 1, the description will be continued. Reference numeral 31 denotes a laser beam scanner unit (laser exposure device) arranged on the lower side of the printer outer casing 1, which includes a semiconductor laser and a scanner motor 3
1a, a polygon mirror 31b, a lens system 31c and the like. The laser signal light 17 corresponding to the time series electric pixel signal of the image information from the scanner unit 31 is the image forming unit of FIG.
Axis 1 through the optical window 32, which is constructed between 12Bk and 12Y
The light enters the fixed mirror 34 in the shaft 15 through the window 33 opened in a part of the optical axis 5 and is reflected and is substantially horizontal from the exposure window 21 of the image forming unit 12Bk in the image forming position 16 into the image forming unit 12Bk. And enters the exposed portion on the left side surface of the photoconductor 18 through the passage between the developer hopper 22 and the cleaner 30 arranged above and below in the image forming unit. Direction scanning exposure.

Here, the optical path from the optical path window 32 to the mirror 34 uses the space between the image forming units 12Bk and 12Y on both sides, so that the image forming unit group 13 has almost no wasted space. be able to. Further, since the mirror 34 is provided in the central portion of the image forming unit group 13, it can be configured by a single fixed mirror, and the configuration is simple and easy to align.

Reference numeral 35 denotes a third transfer roller disposed inside the printer front plate 1A. The printer front plate 1 is provided at the nip portion where the intermediate transfer belt 3 and the third transfer roller 35 are in pressure contact with each other.
A sheet conveying path is formed so that the sheet is fed by the sheet feeding roller 36 provided in the lower part of A. Reference numeral 37 is a paper feed cassette provided on the lower side of the printer front plate 1A so as to project outward, and a plurality of papers S can be set at the same time. 38a and 3
8b is a paper conveyance timing roller, 39a and 39b are fixing roller pairs provided inside the printer, 40 is a paper guide plate provided between the third transfer roller 35 and fixing roller pairs 39a and 39b, and 41a and 41b.
Is a paper discharge roller pair disposed on the paper exit side of the fixing roller pairs 39a and 39b, and 42 is a silicone oil 4 supplied to the fixing roller 39a.
A fixing oil reservoir for storing 3 and 44 is an oil supply roller for applying the silicone oil 43 to the fixing roller 39a.

By the constitution of the electrophotographic apparatus of the present invention, the intermediate transfer belt portion having a complicated constitution can be unitized, so that when the intermediate transfer belt is deteriorated, the user can replace the whole unit and the maintainability is excellent. It becomes a thing. Further, if the belt cleaner is attached to the main body side and only the intermediate transfer belt is exchanged, the position of the belt cleaner and the intermediate transfer belt is likely to be displaced, which easily causes cleaning failure. Since the cleaner and the cleaner are integrally replaced, the positions of the cleaner and the intermediate transfer belt can be fixed, and the occurrence of defective cleaning can be prevented. Also, because the intermediate transfer belt and the waste toner reservoir of the waste toner generated when cleaning the intermediate transfer belt are unitized, it is possible to discard the waste toner processing by exchanging the unit as a unit, and the user's hand during maintenance. Never get dirty. Furthermore, if the intermediate transfer belt unit is configured to be pulled out in the horizontal direction (front side of the paper surface of FIG. 1) with respect to the rotation axis of the photoconductor, the transfer belt 3 and the photoconductor 18 when the unit is attached or detached.
Since the photoconductor was rubbed with each other, the photoconductor was easily scratched, but in the present invention, the intermediate transfer belt unit is configured to be pulled out in the direction perpendicular to the photoconductor rotation axis (the diagonally upper right direction in FIG. 1). The intermediate transfer belt and the photoconductor are not rubbed against each other, and the photoconductor is not damaged.
If the intermediate transfer belt unit is pulled out from the front side of the printer as in the present invention, the structure for attaching and detaching the intermediate transfer belt unit and the structure for removing the paper when the printer jams the paper can be made the same. Becomes simple.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of the color electrophotographic apparatus according to one embodiment of the present invention will be described below with reference to FIGS. First, the operation of the image forming unit will be described with reference to FIG. The photoconductor 18 was charged to -500V by the charging roller 20. Laser beam scanning light (laser signal light) is applied to the photosensitive member 18.
17 was irradiated to form an electrostatic latent image. At this time, the exposure potential of the photoconductor 18 was -100V. 2 on the surface of this photoconductor 18
The component developer 25Bk was adhered in the developer hopper 22 by magnetic force. Next, the surface of the photoconductor 18 was passed in front of the recovery electrode roller 26. When passing through the uncharged area of the photoconductor 18, a 750V 0-p (peak-to-peak 1.5kV) with a DC voltage of + 100V superposed on the recovery electrode roller 26 by an AC high-voltage power supply 28.
AC voltage (rectangular wave of frequency 3 kHz) was applied. Then, the photoconductor 18 charged to −500V and having the electrostatic latent image written thereon
When passing over the surface, the collection electrode roller 26 has an AC high-voltage power supply.
28, an AC voltage (rectangular wave of frequency 3 kHz) of 750 V 0-p (peak-to-peak 1.5 kV) superposed with DC voltage of -300 V was applied. Then, the developer on the photoconductor 18 and the toner attached to the non-image portion are collected by the collection electrode roller 26, and the negative-positive inverted toner image remains only on the image portion on the photoconductor 18. The developer and toner adhering to the collecting electrode roller 26 rotating in the direction of the arrow were scraped off by the scraper 29, returned to the developer hopper 22 and used for the next image formation. Thus, a black toner image was obtained on the photoconductor 18. The same operation was performed for the developing devices 12C, 12M and 12Y other than black.

Next, the operation of the apparatus of FIG. 1 when forming a color image will be described. Initially, the image forming unit group 13 is in the position shown in FIG. 1 and the black image forming unit 12Bk is in the image forming position 16 as shown. At this time, the photoconductor 18 is the intermediate transfer belt 3
It is opposed to the first transfer roller 4 via. By the image forming process of the image forming unit described above, the laser exposure apparatus
Black signal light is input to the image forming unit 12Bk by the (laser beam scanner unit) 31, and an image is formed with black toner. At this time, the image forming speed of the image forming unit 12Bk
The moving speed of the intermediate transfer belt 3 (equal to the peripheral speed of the photoconductor) is set to be the same, and the black toner image is transferred onto the intermediate transfer belt 3 by the action of the first transfer roller 4 at the same time as the image formation. Transcribed. Immediately after the transfer of all the black toner images, the entire image forming unit group 13 of the image forming unit groups 12Bk, 12C, 12M and 12Y is driven by the moving motor 14 and integrally rotated in the direction of the arrow in FIG. Then, the image forming unit 12C rotates exactly 90 degrees and stops at the position where the image forming unit 12C reaches the image forming position 16. During this time, since the toner hopper (developer hopper) 22 and the cleaner 30 (see FIG. 4) other than the photoconductor of the image forming unit are located inside the rotation arc of the tip of the photoconductor 18, the intermediate transfer belt 3 is It does not touch the imaging unit. After the image forming unit 12C arrives at the image forming position 16, as in the previous case, the laser exposure device 31 is now driven by a cyan signal.
Inputs the signal light into the image forming unit 12C, and the cyan toner image is formed and transferred. At this time, the intermediate transfer belt 3 rotates once, and the next cyan toner image is positionally aligned with the previously transferred black toner image.
The writing timing of the cyan signal light is controlled based on the signal from the position detector 10 shown in FIG. During this time, the third transfer roller 35 and the cleaning roller 7 (FIG. 2) are slightly separated from the intermediate transfer belt 3 so that the toner image on the transfer belt is not disturbed. The same operation as described above was performed for magenta and yellow, and the toner images of four colors were positionally aligned and superposed on each other on the intermediate transfer belt 3 to form a color image. After the last transfer of the yellow toner image,
Paper feed cassette 37
It was collectively transferred by the action of the third transfer roller 35 to the paper sent from. The toner image transferred to the paper is fixed to the fixing roller pair 39.
It was established by a and 39b. The paper is then ejected by roller pair 41
It was discharged to the outside of the equipment via a and 41b. The transfer residual toner remaining on the intermediate transfer belt 3 is cleaned by the action of the cleaner roller 7 to prepare for the next image formation. Next, the operation in the single color mode will be described. In the single color mode, first, the image forming unit of a predetermined color is moved to the image forming position. Next, the same color image formation and transfer to the intermediate transfer belt 3 are performed as before. This time, after the transfer, the process is continued as it is, and the next third transfer roller 35 forms the paper sent from the paper feed cassette 37. Transfer and fix as it is.

Next, the maintenance of this device will be described. It is assumed that the developer of a specific color is consumed and maintenance is performed. First, the image forming unit group 13 is rotated by the action of the moving motor 14 to move the image forming unit of the color of interest to the upper position (the position of the image forming unit 12C in FIG. 1). Then, the cover (printer top plate 1C) located on the upper part of the apparatus main body is opened, and the image forming unit of interest is taken out of the apparatus from there. Next, a new image forming unit whose image density has been adjusted in advance is attached. As a result, after the image forming unit is mounted, image formation can be started without any adjustment. The intermediate transfer belt 3 has a life of about 30,000 pages. The waste toner accumulated up to this time is stored in the waste toner reservoirs 9a and 9b. The user opens the cover (front plate 1A) located on the front surface of the apparatus main body, and takes out the intermediate transfer belt unit 2 from the apparatus through the cover. Next, a new unit whose cleaner has already been adjusted is mounted as an intermediate transfer belt unit. Therefore, after mounting the unit, image formation can be started without any adjustment. In the above embodiments, a specific structure was used as the structure of the image forming unit, but the essence and effects of the present invention may be changed even in the case of an image forming unit having a structure using a conventional developing method. There is no.

[0028]

According to the present invention, with the above-described structure, a complicated transfer drum is not required, and a complicated structure for aligning the image exposure system is not required. In addition, the configuration of the toner image forming unit including the photoconductor and the developing unit is unitized, and the intermediate transfer belt unit is also unitized, so it is easy to downsize and maintainability is excellent. This has the effect of providing an apparatus and an intermediate transfer belt unit used for the apparatus. Further, in this configuration, since the intermediate transfer belt unit is pulled out in the direction perpendicular to the rotation axis of the photoconductor, the photoconductor and the transfer belt are not rubbed against each other during the attachment / detachment operation and are not damaged. Furthermore, in this configuration, since the intermediate transfer belt and the waste toner reservoir are integrally configured,
This has the effect that the user's hands can be replaced without getting dirty during maintenance.

[Brief description of 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 an intermediate transfer belt unit used in a color electrophotographic apparatus according to an exemplary embodiment of the present invention.

FIG. 3 is a configuration diagram showing a configuration of a position detector of an intermediate transfer belt unit used in a color electrophotographic apparatus according to an embodiment of the present invention.

FIG. 4 is a configuration diagram showing a configuration of an image forming unit used in a color electrophotographic apparatus according to an embodiment of the present invention.

FIG. 5 is a configuration diagram of a conventional color electrophotographic apparatus.

[Explanation of symbols]

1 ... Exterior casing, 1A ... Front plate, 1B, 1D ... Hinge,
1C ... Printer top plate, 2 ... Intermediate transfer belt unit, 2a ... Unit housing, 3 ... Intermediate transfer belt, 4 ... First transfer roller, 5 ... Second transfer roller,
6 ... tension roller, 7 ... cleaning roller,
8a ... scraper, 9a, 9b ... waste toner storage, 10 ...
… Position detector, 11… Position detection hole, 12Bk, 12C, 12
M, 12Y ... Image forming unit, 13 ... Image forming unit group,
14 ... Moving motor, 15 ... Axis, 16 ... Image forming position, 17
... Laser signal light, 18, 101 ... Photoconductor, 19, 27 ... Magnet, 20 ... Charging roller, 21 ... Exposure window, 22 ... Developer hopper, 23 ... Ferrite carrier, 24 ... Toner, 25
… Two-component developer, 26… Recovery electrode roller, 28… AC high voltage power supply, 29… Scraper, 30,105… Cleaner, 3
1 ... Laser exposure device (laser beam scanner), 31a ...
Scanner motor, 31b ... Polygon mirror, 31c ... Lens system, 32 ... Optical window, 33 ... Window, 34 ... Mirror, 35 ...
Third transfer roller, 36 ... Paper feeding roller, 37 ... Paper feeding cassette, 38a, 38b ... Paper conveyance timing roller, 39 (39
a, 39b) ... Fusing roller pair, 40 ... Paper guide plate, 41 (41
a, 41b) ... Paper discharge roller pair, 42 ... Fixing oil reservoir, 4
3 ... Silicon oil, 44 ... Oil supply roller, 102 ...
Charger, 103 ... Developing unit, 104 ... Transfer drum, 106 ...
Y developing device, 107 ... M developing device, 108 ... C developing device, 109
Bk developing device, 110 laser beam, 111 feeding unit, 112 nail unit, 113 transfer charger, 114 peeling unit, 115 conveying unit, 116 fixing unit.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G03G 15/16 21/10 21/00 350 9122-2H 370 2107-2H

Claims (2)

[Claims] 1. A plurality of movable image forming units, each of which comprises at least a rotating photoconductor and a developing means having a toner of a different color, and which forms a toner image of a different color on the photoconductor. An image forming position composed of a single exposure position and a single transfer position, an image forming unit group in which the plurality of image forming units are annularly arranged, and each of the plurality of image forming units, A moving means for rotating and moving the entire image forming unit group so as to be sequentially positioned at the single image forming position, an exposing means for generating signal light, and an almost rotating center portion of the rotating movement of the image forming unit group. The signal light of the exposure means is guided to the single exposure position and the photoconductor of the image forming unit located at the image forming position is exposed to the signal light and developed with toner. After that, an intermediate transfer belt that transfers the toner image at the single transfer position to form a color toner image in an overlapping manner, and a second transfer that transfers the color toner image on the intermediate transfer member onto an image receiving sheet. A color electrophotographic apparatus having a fixing means for fixing the toner image transferred onto the image receiving sheet, wherein the intermediate transfer belt and a cleaner for cleaning the toner of the intermediate transfer belt are intermediate transfer belt units. And a direction in which the intermediate transfer belt unit is attached to or detached from the casing of the color electrophotographic apparatus is a direction perpendicular to the rotation axis of the photoconductor of the image forming unit. 2. A plurality of movable image forming units each of which includes at least a rotating photoconductor and a developing unit having a toner of a different color, and which forms a toner image of a different color on the photoconductor. An image forming position composed of a single exposure position and a single transfer position, an image forming unit group in which the plurality of image forming units are annularly arranged, and each of the plurality of image forming units, A moving means for rotating and moving the entire image forming unit group so as to be sequentially positioned at the single image forming position, an exposing means for generating signal light, and an almost rotating center portion of the rotating movement of the image forming unit group. The signal light of the exposure means is guided to the single exposure position and the photoconductor of the image forming unit located at the image forming position is exposed to the signal light and developed with toner. After that, the toner image is transferred at the single transfer position, and the intermediate transfer belt that forms the color toner images by overlapping is formed; a belt cleaner that cleans the intermediate transfer belt; and the intermediate transfer belt is cleaned and collected. A waste toner reservoir for accumulating waste toner, a second transfer means for transferring the color toner image on the intermediate transfer body onto an image receiving sheet, and a fixing means for fixing the toner image transferred on the image receiving sheet. A device used in a color electrophotographic apparatus having, wherein the intermediate transfer belt, a belt cleaner for cleaning toner of the intermediate transfer belt, and the waste toner reservoir constitute a unit, and a unit from the color electrophotographic apparatus housing to the An intermediate transfer belt unit configured to be attachable to and detachable from the photoreceptor of the image forming unit in a direction perpendicular to the rotation axis.