JP3131426B2 - Color image recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a color printer,
The present invention relates to a color image recording apparatus applicable to a color copying machine, a color facsimile, and the like, and an intermediate transfer belt unit used for the apparatus.

[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. . As a method of forming this color image,
A toner image of each color is sequentially formed on a single photoconductor, and the transfer material wound around the transfer drum is rotated to repeatedly face the photoconductor. A transfer drum system, and a continuous superimposition system in which multiple image forming units are arranged side by side, and the toner images of each color are sequentially transferred and superimposed on the transfer material conveyed by a belt, etc., at the position of each image forming unit. Is common.

A color image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 1-252982 is one using the former transfer drum system. FIG. 5 shows an outline of the entire configuration of a 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 photoreceptor, which is opposed to the photoreceptor 102, a developing unit 103, a transfer drum 104, and a cleaner 105.
Is provided. The developing unit 103 includes a Y developing unit 106 for forming a yellow toner image, an M developing unit 107 for magenta, a C developing unit 108 for cyan, and a Bk developing unit 109 for black. Then, the entire developing device group rotates, and each developing device sequentially faces the photoconductor 101 to be in a developable state. During operation, the transfer drum 104 and the photoreceptor 101 rotate at a constant speed in the direction of the arrow while facing each other.

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. Thereafter, the surface of the photoconductor 101 is irradiated with a laser beam 110 modulated with a signal for forming a first color yellow image, thereby forming a latent image. Further, this latent image is first developed in the yellow Y developing device 106 facing the photoreceptor to form a yellow toner image.
By the time the formed yellow toner image comes to a position facing the transfer drum 104, one sheet of the transfer material sent from the paper feeding unit 111 is already on the outer periphery of the transfer drum 104 with the claw part The toner image is formed such that the yellow toner image on the photoreceptor is opposed to a predetermined position on the sheet and meets the sheet.

A yellow toner image on a photoreceptor is transferred to a charger.
After being transferred onto the sheet by the action of 113, the surface of the photoreceptor is cleaned by the cleaner 105 to prepare for the formation of the next color image. Subsequently, magenta, cyan, and black toner images are formed in the same manner. At that time, the developing unit 103 sets each developing device used according to the color to a photosensitive member so as to be in a developable state. The diameter of the transfer drum is large enough to allow the longest sheet to be wound and to replace the developing device between images of each color in time.

In the irradiation of the laser beam 110 for forming an image of each color, the toner image of each color on the photoreceptor and the toner image already transferred on the paper on the transfer drum are opposed to each other as the rotation is performed. And so on. In this way, the toner images of the four colors are transferred onto the sheet on the transfer drum 104 in a superimposed manner, and a color image is formed on the sheet. After the toner images of all colors have been transferred, the paper is peeled from the transfer drum 104 by the peeling nails 114,
, The upper toner image is fixed by the fixing device 116, and is discharged out 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 method, there is Japanese Patent Application Laid-Open No. 1-250970. In this example, four image forming stations each including a photoreceptor, an optical scanning unit, and the like are arranged for forming images of four colors.
The paper conveyed to the belt passes under the respective photoconductors, and the toner images are superimposed. Further, as another method of forming a color image by superimposing toner images of different colors on a transfer material, each color toner image sequentially formed on a photoreceptor is temporarily superimposed on an intermediate transfer material, and this is finally finished. Japanese Patent Application Laid-Open No. 2-212867 discloses a method of transferring the transfer material to the transfer material at one time.

[0008]

Among the conventional examples described above, in the transfer drum system, a transfer drum is used to align and overlap toner images of different colors. The 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 each color when forming a color image. However, in the above-described configuration, it is necessary to wind the paper around the transfer drum, so that the diameter of the transfer drum needs to be a certain size or more, and since the structure is very complicated, the apparatus becomes large. Had become.
Also, stiff paper such as postcards and cardboard cannot be used because they 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 sheet must be passed one after another to eliminate the need for a transfer drum. A plurality of latent image forming means such as a laser optical system for forming a latent image thereon is required in accordance with the number of colors, and the structure becomes very complicated and expensive. Furthermore, since there are a plurality of image forming positions, the relative positional relationship between the image forming units of each color greatly affected the color shift. In particular, it is necessary to accurately perform the alignment between the respective colors of the latent image by the latent image forming means, and as shown in Japanese Patent Application Laid-Open No. 1-250970, it corresponds to an image exposure system which is a latent image forming means. There was a problem that a device and a complicated configuration were required.

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a color image recording apparatus in which the structure of an intermediate transfer unit is small, simple, and excellent in maintainability, and an intermediate transfer belt unit used therefor.

[0011]

According to the color image recording apparatus of the present invention, the shaft side is formed smaller than the outer peripheral side and a part thereof is formed.
A plurality of columnar pieces of the same shape having a color toner storage section
Separate units can be attached and detached only in the direction perpendicular to the rotation axis
In this state, the rotating body assembled and arranged in a substantially cylindrical shape
Image forming means for forming a color image;
And the belt width is wider than the maximum screen width and
Color for each color sequentially from the photoreceptor
An intermediate transfer belt for transferring an image and this intermediate transfer belt
A plurality of supporting rollers, and a rotating shaft of the photoconductor.
Inside the main unit in a state where it can be detached vertically
An intermediate transfer belt unit and the intermediate transfer from the photoconductor
After transferring the color images of all colors to the belt,
To transfer a color image from an intermediary transfer belt to recording paper
Means and a color image on the recording paper after the transfer is completed.
The fixing means for fixing and the belt position detecting sensor
By detecting the shooting standby position, the image forming means
Control the timing of forming a color image on a photoreceptor,
Indicates the position of the color image to be transferred to the intermediate transfer belt.
Control means for performing the alignment.
The unit collects the color toner stored in the unit in advance.
It has a single opening to supply to the outside of the
In the replacement position with the opening positioned sideways.
And stop with the opening positioned upward.
And when replacing the columnar individual unit,
Stop at the exchange position with the opening facing upward
Opening and closing the top of the device only in the state perpendicular to the axis of the rotating body
The intermediate transfer belt unit.
The knit has a mark for position detection on the intermediate transfer belt.
Photo interrupt having a light emitting part and a light receiving part for detecting
Housing a belt position detection sensor composed of
Also, do not move other image forming means from the image forming position.
From the opening / closing part on the front of the device
Can be mounted at the stand-by position and replace the unit
The photoconductor so that the surface of the photoconductor is not damaged.
Away from the photoconductor in the direction perpendicular to the rotation axis,
From the opening / closing section on the front of the device.
It is configured to be possible. This makes it possible to obtain a color image recording apparatus having a compact, simple and easy-to-maintain intermediate transfer belt unit, and to accurately control the timing of color image formation by the image forming means or to accurately transfer the color image. be able to.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A color image recording apparatus according to a first embodiment of the present invention is provided with an image forming means for forming a color image on a photoreceptor, and disposed opposite to the photoreceptor, wherein a belt width is larger than a maximum screen width. An intermediate transfer belt that has a position detection mark widely outside the screen area and sequentially transfers color images of each color from the photoconductor and a plurality of rollers that support the intermediate transfer belt are housed therein, and are perpendicular to the rotation axis of the photoconductor. An intermediate transfer belt unit housed in the apparatus body in a detachable state in the direction, and after transferring color images of all colors from the photoconductor to the intermediate transfer belt, the color images are transferred from the intermediate transfer belt to recording paper. A transfer unit for transferring, a fixing unit for fixing a color image on the recording paper after the transfer is completed, and a position adjustment of the color image based on the position detection mark. A color image recording apparatus according to a second aspect of the present invention includes: an image forming unit that forms a color image on a photoconductor;
An intermediate transfer belt that is disposed opposite to the photoconductor, has a belt width wider than a maximum screen width, has a position detection mark outside a screen area, and sequentially transfers color images of each color from the photoconductor, and supports the intermediate transfer belt. Accommodates multiple rollers,
An intermediate transfer belt unit housed in an apparatus body detachably in a direction perpendicular to a rotation axis of the photoconductor, and after transferring color images of all colors from the photoconductor to the intermediate transfer belt, the intermediate transfer Transfer means for transferring a color image from a belt to a recording sheet; fixing means for fixing the color image on the recording sheet after the transfer; a belt position detection sensor for detecting a position detection mark on the intermediate transfer belt; And a timing at which a color image is formed on a photoreceptor by the image forming means by controlling a predetermined position by the belt position detecting sensor. According to a third aspect of the present invention, in the color image recording apparatus according to the second aspect, the belt position detection sensor is configured to control the belt position detection sensor to be downstream of the transfer position from the intermediate transfer belt to the recording paper and to transfer the photoconductor to the intermediate transfer belt. It is configured to be provided upstream of the position. The color image recording apparatus according to the fourth aspect of the present invention has a third aspect.
In the embodiment, the cleaning means for the intermediate transfer belt is provided on the downstream side of the transfer position from the intermediate transfer belt to the recording paper and on the upstream side of the belt position detection sensor.
A color image recording apparatus according to a fifth aspect of the present invention is the same as the second aspect, except that the belt position detection sensor is provided in the intermediate transfer belt unit. The present invention 6
In the color image recording apparatus according to any one of the second to fifth aspects, the belt position detection sensor is a photo interrupter having a light emitting unit and a light receiving unit. According to a seventh aspect of the present invention, there is provided a belt position detecting method for an intermediate transfer belt unit, wherein a color image is formed on a photoreceptor, and then the color images of respective colors are sequentially stored in the intermediate transfer belt unit from the photoreceptor. And a color image recording apparatus of an intermediate transfer belt type, in which a color image of all colors is transferred from the photoreceptor to the intermediate transfer belt, and then the color image is transferred from the intermediate transfer belt to recording paper and fixed. In the belt position detecting method of the intermediate transfer belt unit used in the method, a position detection mark is provided at an end of the intermediate transfer belt, and a position detection mark of the intermediate transfer belt unit is provided at a corresponding position on a circuit path. A belt position detection sensor for detecting the position detection mark is arranged, and the position detection mark is optically detected. . In the color recording method according to the eighth aspect of the present invention, after a color image is formed on a photoreceptor, color images of respective colors are sequentially transferred from the photoreceptor to an intermediate transfer belt,
A color recording method in an intermediate transfer belt type color image recording apparatus, wherein a color image is transferred from the intermediate transfer belt to a recording sheet and then fixed after transferring color images of all colors to the intermediate transfer belt. The intermediate transfer belt is arranged so as to be housed in an intermediate transfer belt unit that is disposed to face the photoconductor and that is detachably attached to the apparatus main body. A position detection mark is provided outside the area, the position detection mark is detected by a position detection sensor, and based on the detected position of the intermediate transfer belt, a color image forming timing of an image forming unit is controlled.
Alternatively, the transfer position of a color image is adjusted. The ninth mode of the present invention is used in the color image recording apparatus of any one of the first to sixth modes. Further, the following configuration may be adopted. A color image recording apparatus according to another aspect of the present invention includes a photoreceptor that rotates at least and a developing unit that includes toners of different colors, and forms toner images of different colors on the photoreceptor. A plurality of movable image forming units, an image forming position including a single exposure position and a single transfer position, an image forming unit group in which the plurality of image forming units are arranged in an annular shape, Moving means for rotating and moving the entire image forming unit group to sequentially position each of the image forming units at the single image forming position; exposure means for generating signal light; and rotation of the image forming unit group. The mirror is disposed substantially at the center of rotation of the movement, and guides the signal light of the exposure unit to the single exposure position, and exposes the signal light to the photosensitive member of the image forming unit located at the image forming position. After developing with toner, the toner image is transferred at the single transfer position, and an intermediate transfer belt that forms a color toner image by superimposition, and a color toner image on the intermediate transfer body are placed on an image receiving sheet. What is claimed is: 1. A color image recording apparatus comprising: a second transfer unit that transfers a toner image; and a fixing unit that fixes a toner image transferred onto the image receiving sheet. The intermediate transfer belt, and a cleaner that cleans toner of the intermediate transfer belt Constitute an intermediate transfer belt unit, and the direction of attachment / detachment of the intermediate transfer belt unit from the casing of the color image recording apparatus is perpendicular to the rotation axis of the photoconductor of the image forming unit. An intermediate transfer belt unit according to another aspect of the present invention includes a photoreceptor that rotates at least and developing means having toners of different colors, and forms toner images of different colors on the photoreceptor. A plurality of movable image forming units;
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 arranged in an annular shape, and each of the plurality of image forming units, Moving means for rotating and moving the entire image forming unit group to sequentially position at one image forming position, exposing means for generating signal light, and being disposed substantially at the center of rotation of the rotational movement of the image forming unit group; A mirror that guides the signal light of the exposure unit to the single exposure position, and the signal light is exposed to a photosensitive member of an image forming unit located at the image forming position, and after developing with toner, the toner image is formed. An intermediate transfer belt that transfers images at a single transfer position and forms a superimposed color toner image; a belt cleaner that cleans the intermediate transfer belt; and a cleaning device that cleans the intermediate transfer belt. A waste toner reservoir for storing the collected waste toner, a second transfer unit for transferring a color toner image on the intermediate transfer member onto an image receiving sheet, and a fixing unit for fixing the toner image transferred onto the image receiving sheet Wherein the intermediate transfer belt, a belt cleaner for cleaning the toner of the intermediate transfer belt, and the waste toner reservoir constitute a unit, and a color image recording device housing From the photosensitive member of the image forming unit can be attached and detached in the direction perpendicular to the rotation axis.

[0013] Regarding the configuration of the color image recording apparatus,
An example of a color electrophotographic apparatus will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes an outer casing of a color electrophotographic printer, and a right end face side in the drawing is a front face. Reference numeral 1A denotes a printer front plate. The front plate can be freely opened and closed as shown by a two-dot chain line and raised and closed as shown by a solid line with respect to a 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 inside of the printer, and checking / maintenance / maintenance of the inside of the printer such as at the time of paper jam are performed by opening the front plate 1A to open the inside of the printer largely. The attachment / detachment operation of the intermediate transfer belt unit 2 is designed to be perpendicular to the rotation axis of the photoconductor.

FIG. 2 shows the structure of the intermediate transfer belt unit 2. The intermediate transfer belt unit 2 includes a unit housing 2a, an intermediate transfer belt 3, and a first conductive elastic body.
A transfer roller 4, a second transfer roller composed of an aluminum roller 5, a tension roller 6 for adjusting the tension of the intermediate transfer belt 3, a cleaning roller 7 for cleaning the toner image remaining on the intermediate transfer belt 3, and a cleaning roller 7
1 includes a scraper 8 for scraping the collected toner, waste toner reservoirs 9a and 9b for storing the collected toner, and a position detector 10 for detecting the position of the transfer belt. 1A is folded down like a two-dot chain line and opened to be detachable from a predetermined storage portion in the printer outer casing 1.

The intermediate transfer belt 3 is formed of an endless belt-like semiconductive urethane film having a thickness of 100 μm, and a first transfer roller 4 and a first transfer roller 4 around which are formed a urethane foam having a low resistance treatment. 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 set to a length (298 mm) in the longitudinal direction of A4 paper, which is the maximum paper size, and a photosensitive drum described later.
The length is set to 350 mm, which is a length (52 mm) that is slightly longer than half of the circumference of (diameter 30 mm).

The conductive first transfer roller 4 is 10 ⁷
It has a resistance of Ωcm, and when it is attached to the printer body, it is pressed against the photoreceptor via 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 that of the above-described first transfer roller 4 is lightly pressed to 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 section for cleaning the intermediate transfer belt 3. This is a configuration in which an AC voltage for electrostatically attracting 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. A position detection hole 11 is provided at an end of the intermediate transfer belt 3, and a position detector 10 optically detects the passage of the position detection hole 11 to adjust the position of the color image on the intermediate transfer belt 3. Configuration.

Referring back to FIG. Black in the center of the printer,
Four 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 figure. Each image forming unit is detachable at a predetermined position of the image forming unit group 13 by opening the printer upper plate 1C of FIG. 1 around the hinge 1D. The image forming unit 12 is properly mounted 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 via a mutual coupling member (not shown). And electrical integration.

An 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 as a whole, and are rotatable about a fixed, non-rotating cylindrical shaft 15. It has become. Each image forming unit can be sequentially positioned at the image forming position 16 facing the second transfer roller 4 supporting the above-described intermediate transfer belt 3. The image forming position 16 is also an exposure position by the laser signal light 17.

Each of the image forming units is made of the same constituent members except for the developer to be put into the image forming units. Therefore, the image forming unit 12Bk for black will be described in order to simplify the description.
The description of other colors is omitted. Note that, for each color, the same portions are denoted by the same reference numerals, and when it is necessary to distinguish the configuration of each color, a character indicating each color is denoted by the reference numeral. FIG.
The image forming unit 12Bk for black is shown in detail in FIG. here,
Although the inventors have used the developing method disclosed in Japanese Patent Application No. 4-50274, it goes without saying that any developing method may be used as long as it is a developing method used in a general electrophotographic method. In FIG. 4, 18 is an organic photoreceptor in which phthalocyanine is dispersed in a polycarbonate binder resin, 19 is a non-rotating magnet fixed coaxially with the photoreceptor 18, 20 is a charging roller for negatively charging the photoreceptor 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. A two-component developer 25Bk obtained by mixing a ferrite carrier 23Bk having a particle diameter of 50 μm and a toner 24Bk in which a black pigment is dispersed in a polyester resin is put into the developer hopper 22 and the photosensitive member is magnetized by the magnet 19. 18 Adhere to the surface. 26
Is a rotatable collecting electrode roller made of aluminum, 27 is a non-rotating magnet coaxially fixed inside, 27 is an AC high-voltage power supply for applying a voltage to the collecting electrode roller 26, and 29 is a toner on the collecting electrode roller 26. A scraper made of polyphenylene sulfide to be scraped off. The diameter of the photoconductor 18 is 30 mm
And rotate it in the direction of the arrow at a peripheral speed of 60 mm / s
26 has 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 denotes 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 below the inside of the printer outer casing 1, and includes a semiconductor laser, 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 applied to the image forming unit shown in FIG.
Through the optical path window 32 formed between 12Bk and 12Y, the axis 1
The light enters a fixed mirror 34 in the shaft 15 through a window 33 opened in a part of 5, and is reflected and substantially horizontal from the exposure window 21 of the image forming unit 12Bk at the image forming position 16 into the image forming unit 12Bk. Through the passage between the developer hopper 22 and the cleaner 30 disposed vertically in the image forming unit, and enters the exposed portion on the left side of the photoreceptor 18, and the surface of the photoreceptor 18 Scanning exposure is performed in the direction.

Here, since the optical path from the optical path window 32 to the mirror 34 utilizes the gap between the adjacent image forming units 12Bk and 12Y, the image forming unit group 13 almost eliminates wasted space. be able to. Further, since the mirror 34 is provided at the center of the image forming unit group 13, the mirror 34 can be constituted by a single fixed mirror, which is simple and easy to align.

Reference numeral 35 denotes a third transfer roller disposed inside the printer front plate 1A. A nip portion where the intermediate transfer belt 3 and the third transfer roller 35 are pressed against each other is provided with a printer front plate 1A.
A sheet transport path is formed so that the sheet is fed by a sheet feed roller 36 provided below A. Reference numeral 37 denotes a sheet cassette provided on the lower side of the printer front plate 1A so as to protrude outward, and can set a plurality of sheets S at the same time. 38a and 3
8b is a paper transport timing roller, 39a and 39b are a pair of fixing rollers provided on the upper inside of the printer, 40 is a paper guide plate provided between the third transfer roller 35 and the pair of fixing rollers 39a and 39b, 41a and 41b.
Is a pair of paper discharge rollers disposed on the paper exit side of the pair of fixing rollers 39a and 39b, and is a silicone oil 4 supplied to the fixing roller 39a.
Reference numeral 44 denotes an oil supply roller for applying silicone oil 43 to the fixing roller 39a.

According to the configuration of the electrophotographic apparatus of the present invention, the intermediate transfer belt portion having a complicated configuration can be unitized, so that when the intermediate transfer belt is deteriorated, the user can replace the entire unit and the maintenance is excellent. It will be. Furthermore, if the belt cleaner is attached to the main body and only the intermediate transfer belt is replaced, the position of the belt cleaner and the intermediate transfer belt is easily shifted, which is likely to cause a cleaning failure. And the cleaner are integrally replaced, so that the position of the cleaner and the intermediate transfer belt can be fixed, and the occurrence of poor cleaning can be prevented. In addition, since the intermediate transfer belt unit and the waste toner reservoir generated when the intermediate transfer belt is cleaned are unitized, the waste toner processing can be discarded by exchanging the entire unit. Will not pollute. Further, if the intermediate transfer belt unit is configured to be pulled out in the horizontal direction (on the front side in FIG. 1) with respect to the rotation axis of the photoconductor, the transfer belt 3 and the photoconductor 18
In the present invention, the intermediate transfer belt unit is pulled out in a direction perpendicular to the rotation axis of the photoreceptor (in the upper right direction in FIG. 1). The transfer belt and the photoconductor are not rubbed with each other, and the photoconductor is not damaged. When the intermediate transfer belt unit is drawn out from the front side of the printer as in the present invention, the configuration for attaching and detaching the intermediate transfer belt unit and the configuration for removing the paper when the paper jams in the printer can be made the same. Becomes simple.

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 photoreceptor 18 was charged to -500 V by the charging roller 20. Laser beam scanning light (laser signal light)
Irradiation was carried out to form an electrostatic latent image. At this time, the exposure potential of the photoreceptor 18 was -100V. On the surface of this photoreceptor 18, 2
The component developer 25Bk was deposited in the developer hopper 22 by magnetic force. Next, the surface of the photoconductor 18 was passed in front of the collection electrode roller 26. When the photosensitive member 18 passes through the uncharged area, the recovery electrode roller 26 is superimposed with a DC voltage of +100 V by an AC high-voltage power supply 28 to 750 V0-p (1.5 kV peak-to-peak).
AC voltage (rectangular wave having a frequency of 3 kHz) was applied. Thereafter, the photosensitive member 18 charged to -500 V and the electrostatic latent image is written thereon
When passing through the surface, the collection electrode roller 26 has an AC high-voltage power supply.
According to 28, an AC voltage (rectangular wave having a frequency of 3 kHz) of 750 V0-p (1.5 kV peak-to-peak) superimposed with a DC voltage of -300 V was applied. Then, the developer and the toner attached to the non-image portion on the photoreceptor 18 were collected by the collection electrode roller 26, and a negative-positive toner image was left only on the image portion on the photoreceptor 18. The developer and toner adhering to the collection electrode roller 26 rotating in the direction of the arrow were scraped off by the scraper 29, returned to the developer hopper 22 again, and used for the next image formation. Thus, a black toner image was obtained on the photoreceptor 18. The same operation was performed for the other developing units 12C, 12M, and 12Y other than black.

Next, the operation of the apparatus shown in FIG. 1 when forming a color image will be described. Initially, the image forming unit group 13 is at the position shown in FIG. 1, and the black image forming unit 12Bk is at the image forming position 16 as shown. At this time, the photosensitive member 18 is
Is opposed to the first transfer roller 4. By the image forming process of the image forming unit described above, the laser exposure apparatus
(Laser beam scanner unit) 31 inputs a black signal light to the image forming unit 12Bk, and forms an image with black toner. At this time, the image forming speed of the image forming unit 12Bk
(Equal to the peripheral speed of the photoconductor) and the moving speed of the intermediate transfer belt 3 are set to be the same, and the black toner image is transferred to the intermediate transfer belt 3 by the action of the first transfer roller 4 simultaneously with the image formation. Transcribed. Immediately after all of the black toner images have been transferred, the image forming unit groups 12Bk, 12C, 12M, and 12Y are 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 portions of 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 at the tip of the photoconductor 18, the intermediate transfer belt 3 Does not contact the image forming unit. After the image forming unit 12C arrives at the image forming position 16, as before, this time, the laser exposure device 31 is operated with a cyan signal.
Inputs signal light to the image forming unit 12C, and formation and transfer of a cyan toner image are performed. At this time, the intermediate transfer belt 3 makes one rotation, and the next cyan toner image coincides in position with the previously transferred black toner image in FIG.
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 as not to disturb the toner image on the transfer belt. The same operation as above was performed for magenta and yellow, and the four color toner images were superimposed on the intermediate transfer belt 3 in a position-matched manner to form a color image. After the transfer of the last yellow toner image,
The four color toner images are adjusted in timing with the paper feed cassette 37.
Are collectively transferred to the sheet fed from the printer by the action of the third transfer roller 35. The transferred toner image is transferred to the fixing roller pair 39.
a, 39b. The paper is then ejected to pair 41
a, and was discharged outside the device via 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 monochrome mode will be described. In the single color mode, first, an image forming unit of a predetermined color is moved to an image forming position. Next, image formation of a predetermined color and transfer to the intermediate transfer belt 3 are performed in the same manner as before, and this transfer is continued as it is, and the next third transfer roller 35 transfers the image to the sheet fed from the sheet cassette 37. Transfer and fix.

Next, the maintenance of the apparatus will be described. It is assumed that a 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, and the image forming unit of the target color is moved to the upper position (the position of the image forming unit 12C in FIG. 1). Then, the cover (printer top plate 1C) located at the top of the apparatus body is opened, and the image forming unit of interest is taken out of the apparatus from the cover. Next, a new image forming unit whose image density has been adjusted in advance is mounted. Thus, after the image forming unit is mounted, image formation can be started without any adjustment. The life of the intermediate transfer belt 3 is about 30,000 pages. The waste toner accumulated up to this time is accumulated in the waste toner reservoirs 9a and 9b. The user opens the cover (front plate 1A) located at the front of the apparatus main body, and takes out the intermediate transfer belt unit 2 out of the cover. Next, a new unit with a cleaner or the like adjusted in advance is mounted as an intermediate transfer belt unit. Therefore, after the unit is mounted, image formation can be started without any adjustment. In the above embodiment, the structure of the image forming unit is the same as that of the first embodiment. However, even in the case of an image forming unit having a structure using a conventional developing method, the essence and the function and effect of the present invention vary. Nothing.

[0028]

According to the present invention, the above arrangement eliminates the need for a complicated transfer drum and eliminates the need for a complicated arrangement for aligning the image exposure system. In addition, since the configuration of the toner image forming unit including the photoreceptor and the developing unit is unitized, and the intermediate transfer belt unit is also unitized, excellent color image recording that is simple, compact, and easy to maintain. This has the effect that an apparatus and an intermediate transfer belt unit used for the apparatus can be obtained. Further, in this configuration, since the intermediate transfer belt unit is configured to be 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 attaching / detaching operation, so that they are not damaged. Furthermore, in this configuration, since the intermediate transfer belt and the waste toner reservoir are integrally configured,
This has the effect of allowing replacement without soiling the user's hands during maintenance.

[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 an intermediate transfer belt unit used in the color electrophotographic apparatus according to one 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 the color electrophotographic apparatus according to one 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 one embodiment of the present invention.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Exterior case 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 reservoir 10 Position detector 11 Position detection hole 12Bk, 12C, 12M, 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 31 Laser exposure device (laser beam scanner) 31a Scanner motor 31b Polygon mirror 31c Lens system 32 Optical path Window 33 Window 34 Mirror 35 Third transfer roller 36 Paper feed roller 37 Paper feed Cassette 38a, 38b: Paper transport timing roller 39 (39a, 39b) Fixing roller pair 40 Paper guide plate 41 (41a, 41b) Paper discharge roller pair 42 Fixing oil reservoir 43 Silicon oil 44 Oil supply roller 102 Charger 103 Developing unit 104 Transfer drum 106 Y developing unit 107 M developing unit 108 C developing unit 109 Bk developing unit 110 Laser beam 111 Paper feed unit 112 Claw unit 113 Transfer charger 114 Peeling claw 115 Transport unit 116 Fixing unit

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-4-110871 (JP, A) JP-A-3-191368 (JP, A) JP-A-4-116573 (JP, A) JP-A-4-110 102840 (JP, A) JP-A-60-208779 (JP, A) JP-A-2-300769 (JP, A) JP-A-3-78771 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 13/01 G03G 15/01-15/01 117 G03G 15/16 G03G 15/00 550 G03G 15/08-15/095

Claims (5)

(57) [Claims] A plurality of individual columnar units each having the same shape and having a shaft side smaller than the outer peripheral side and having a color toner accommodating portion in a part thereof are substantially circular in a state where they can be attached and detached only in a direction perpendicular to the rotation axis. A rotating body collectively arranged in a columnar shape; an image forming means for forming a color image on the photoreceptor; and a position detection mark disposed outside the screen area, wherein the belt width is wider than the maximum screen width and is disposed opposite to the photoreceptor. Contains an intermediate transfer belt and a plurality of rollers supporting the intermediate transfer belt for sequentially transferring color images of each color from the photoconductor,
An intermediate transfer belt unit housed in an apparatus body detachably in a direction perpendicular to a rotation axis of the photoconductor, and after transferring color images of all colors from the photoconductor to the intermediate transfer belt, the intermediate transfer A transfer unit that transfers a color image from a belt to a recording sheet; a fixing unit that fixes the color image on the recording sheet after the transfer is completed; and a photoconductor formed by the image forming unit by detecting the position detection mark. Controlling the timing of forming a color image on the top, or a control means for performing alignment of the color image to be transferred to the intermediate transfer belt, the column-shaped individual unit, the color toner previously stored in the unit A single opening for supply to the outside of the unit, wherein the opening is located sideways in the developing position and the opening is The upper surface of the apparatus is opened and closed in a direction perpendicular to the axis of the rotator only when the columnar individual unit is replaced, and only when stopped at the replacement position with the opening facing upward when the columnar individual unit is replaced. The intermediate transfer belt unit houses a belt position detection sensor configured by a photointerrupter having a light emitting unit and a light receiving unit, which detects a position detection mark on the intermediate transfer belt. Without moving other image forming means from the image forming position.
It can be taken out of the apparatus from the opening / closing section on the front of the apparatus and can be mounted at the transfer standby position, and is separated from the photoconductor in a direction perpendicular to the rotation axis of the photoconductor so as not to damage the surface of the photoconductor when replacing the unit. A color image recording apparatus, wherein the color image recording apparatus is configured to be able to be taken out from an opening / closing section on the front of the apparatus by being pulled out to the front of the apparatus. A belt position detection sensor provided downstream of the transfer position from the intermediate transfer belt to the recording paper and upstream of the transfer position from the photosensitive member to the intermediate transfer belt; 2. The color image recording apparatus according to claim 1, further comprising cleaning means for the intermediate transfer belt. 3. A plurality of individual printers each having a color toner storage section.
Units can be attached and detached in the direction perpendicular to the rotation axis.
A rotating body collectively arranged in a substantially columnar shape, an image forming means for forming a color image on the photoconductor, and arranged opposite to the photoconductor, and a belt width is larger than a maximum screen width.
Also has a position detection mark outside the screen area widely
Intermediate transfer belt that transfers color images of each color sequentially from
And a plurality of rollers for supporting the intermediate transfer belt of
Detachable vertically to the rotation axis of the photoconductor
A color image is transferred from the accommodated intermediate transfer belt unit to the intermediate transfer belt from the photoconductor.
Color image on the recording paper from the intermediate transfer belt.
A transfer unit for transferring an image, and a fixing unit for fixing a color image on a recording sheet after the completion of the transfer.
The image forming by detecting the position detecting mark.
Control the timing of color image formation on the photoreceptor
The color image to be transferred or transferred to an intermediate transfer belt
Control means for performing positioning of the color unit , wherein the individual unit is a color cartridge housed inside the unit.
And an opening for supplying the toner to the outside of the unit.
In the state where the opening is located on the side, the replacement position
In the state where the opening is located above,
While stopping, when replacing the individual unit,
With the opening facing upward, the shaft of the rotating body is
It is configured to be removable from the opening / closing section on the top of the device in the vertical direction
On the other hand, the intermediate transfer belt unit is provided on the intermediate transfer belt.
It has a light-emitting part and a light-receiving part for detecting the position detection mark.
Belt position is configured in a photo-interrupter to 置検Dese
The photoconductor is separated from the photoconductor in a direction perpendicular to the rotation axis of the photoconductor.
A color image recording apparatus configured to be detachable from an opening / closing section on the front surface of the apparatus. 4. A belt position detecting sensor comprising: an intermediate transfer belt;
Downstream from the transfer position to the recording paper and from the photoconductor
Provided on the upstream side of the transfer position to the intermediate transfer belt;
Cleaning of the intermediate transfer belt upstream of the
4. A collar according to claim 3, further comprising:
-Image recording device. 5. A color toner unit contained in a unit.
Multiple individual units with openings to supply to the outside
Assembled in a substantially cylindrical shape, detachable in the direction perpendicular to the rotation axis
The opening portion at the developing position
Stops in the side position while the replacement position
And stop with the opening positioned above
The individual unit in a state where the opening is directed upward.
In the state, in the direction perpendicular to the axis of the rotating body, the opening and closing part of the upper surface of the device
A rotating body configured to be detachable from, and an image formed on a photoconductor by the color toner,
Transfers to the intermediate transfer body accommodated in the intermediate transfer unit, and updates
A means for fixing after transferring to recording paper ; and
Also has a position detection mark outside the screen area widely
Intermediate transfer belt that transfers color images of each color sequentially from
And a plurality of rollers for supporting the intermediate transfer belt of
Detachable vertically to the rotation axis of the photoconductor
By detecting the stored intermediate transfer belt unit and the position detection mark , the transfer onto the photoconductor is performed.
Color image forming timing or the intermediate transfer
A system for adjusting the position of the color image to be transferred to the belt
Control means, wherein the intermediate transfer belt unit is provided on the intermediate transfer belt.
It has a light-emitting part and a light-receiving part for detecting the position detection mark.
Belt position detection
And a direction perpendicular to the rotation axis of the photoconductor.
Away from the photoreceptor, and from the opening / closing section on the front of the apparatus.
A color image recording device , which is detachably configured .