JP3163087B1 - Color image recording device - Google Patents

Abstract

The present invention provides a color image recording apparatus in which the configuration of an intermediate transfer unit is small, simple, easy to maintain, and free from color misregistration. SOLUTION: A plurality of individual units 13Y, 13M, 1
An image forming unit group 14 in which 3C and 13BK are collectively arranged in a detachable state in a substantially cylindrical shape, and an intermediate transfer body unit 2 that houses the intermediate transfer body 3 are provided. The stop position of the image forming unit group 14 is determined by the individual units 13Y, 13M, 13
One of C and 13BK is located at the image forming position and has an image forming position used for image forming, and all the individual units have a retreating position where the individual units are not located at the image forming position. The intermediate transfer body unit 2 is configured to be detachable from the direction perpendicular to the rotation axis of the image forming unit group 14 only when the image forming unit group 14 is in the retracted position.

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.

[0002]

2. Description of the Related Art In a general color electrophotographic method, a color image is formed by superimposing yellow, magenta, cyan, and black toner images on an image receiving paper. In this color image forming method, a toner image of each color is sequentially formed on a single photoreceptor, and an image receiving paper wound around an intermediate transfer member is rotated to repeatedly oppose the photoreceptor, and each color formed there is sequentially formed. An intermediate transfer body system that transfers the toner images in a superimposed manner, and a plurality of image forming units are arranged side by side,
In general, a continuous superimposition method in which toner images of each color are sequentially transferred to an image receiving paper conveyed by a belt through respective image forming units and the color images are superimposed.

A color image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 1-252982 is one that uses a method of winding an image receiving paper around an intermediate transfer member. FIG. 10 shows an outline of the entire configuration of the conventional example, and the configuration and operation will be briefly described below. In FIG. 10, reference numeral 101 denotes a photoreceptor, on which a charger 102, a developing unit 103, an intermediate transfer body 104, and a cleaner 105 are provided. Developing unit 10
Reference numeral 3 denotes a Y developing device 10 for forming a yellow toner image.
6. M developing unit 107 of magenta color, C developing unit 108 of cyan color, and Bk developing unit 109 of black color. The entire developing unit group rotates, and each developing unit sequentially faces the photoconductor 101 and develops. It becomes possible. During operation, the intermediate transfer member 112 and the photosensitive member rotate at a constant speed in the direction of the arrow while facing each other.

When the image forming operation is started, the photosensitive member 101 rotates in the direction of the arrow, and its surface is uniformly charged by the charger 102. Thereafter, the surface of the photoconductor is irradiated with a laser beam 110 modulated with a signal for forming a first color yellow image, thereby forming a latent image. Next, this latent image is first developed by the Y developing device 106 facing the photoconductor.
To form a yellow toner image. The yellow toner image formed on the photoreceptor is
By the time it moves to the position facing the
A sheet of paper as image receiving paper sent from the paper feeding unit 111 is wound around the outer periphery of the paper 04 with the claw 112 and the yellow toner image on the photoreceptor is placed at a predetermined position on the paper. Are timed to meet in opposition.

After the yellow toner image on the photoreceptor is transferred to the sheet by the action of the transfer charger 113, the surface of the photoreceptor is cleaned by the cleaner 105 to prepare the next color image formation. 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 intermediate transfer member is large enough to allow the longest sheet to be wound thereon and to replace the developing device between images of each color in time.

[0006] Laser beam 110 for image formation of each color
Is performed at a timing such that the toner images of the respective colors on the photosensitive member and the toner images already transferred onto the sheet on the intermediate transfer member are positioned and matched with each other as they rotate, and face each other. In this manner, the four color toner images are transferred to the intermediate transfer member 10.
4, the image is transferred onto the sheet, and a color image is formed on the sheet. After the toner images of all colors have been transferred, the paper is peeled off from the intermediate transfer body 104 by the peeling claws 114, the toner image is fixed by the fixing device 116 via the transporting unit 115, and is discharged out of the apparatus. Finally, the surface of the intermediate transfer member 104 is cleaned with a cleaner 119 because the surface of the intermediate transfer member 104 is stained with toner.

Further, as another method of forming a color image by superimposing toner images of different colors on a transfer material, a method of superimposing toner images of respective colors sequentially formed on a photoreceptor on an intermediate transfer member, and Japanese Patent Application Laid-Open No. Hei 2-212867 discloses a method of transferring the toner image on the intermediate transfer member to an image receiving sheet.

[0008]

In a system in which an image receiving paper is wound around an intermediate transfer body, an intermediate transfer drum is used to align and overlap toner images of different colors. The intermediate 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 configuration, it is necessary to wind the paper around the intermediate transfer body, so that the diameter of the intermediate transfer body needs to be a certain size or more, and the structure is very complicated and high precision is required. Therefore, the apparatus is large and expensive. Further, since the intermediate transfer member 104 has a structure different from that of the cleaner 119, it is necessary to separately perform maintenance of the cleaner 119 when replacing the intermediate transfer member. Further, although the intermediate transfer body itself has a life, it is difficult to automatically detect the replacement time, so a serviceman had to periodically visit the user to check whether the replacement was necessary. . Further, in such a configuration, since the maintenance is performed while the intermediate transfer body and the photoconductor are in contact with each other, the surface of the photoconductor 101 is damaged when the intermediate transfer body is replaced, or light from the outside is directly applied to the photoconductor. This also caused deterioration of the photoreceptor.

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 section is small and simple, and has good maintainability.

[0011]

A color image recording apparatus according to the present invention has an individual unit assembly in which a plurality of individual units accommodating a color toner are detachably arranged, and is provided on a photosensitive member. In a color image recording apparatus that transfers an exposed and developed image to recording paper via an intermediate transfer body housed in an intermediate transfer unit, the individual unit assembly includes one of the individual units at an image forming position. The intermediate transfer unit is controlled so as to be movable to two positions of an image forming arrangement to be arranged and a retracting arrangement in which all the individual units are not located at the image forming position. It is configured to be detachable from the device main body only when it is in the arrangement. In addition, it has an individual unit assembly in which a plurality of individual units each having a color toner storage unit and a photoconductor are detachably arranged, and an image exposed and developed on the photoconductor is transferred to an intermediate transfer unit. In a color image recording apparatus for transferring to recording paper via a stored intermediate transfer body, the individual unit assembly includes an image forming arrangement in which one of the individual units is arranged in an image forming position, and all of the individual units. The unit is controlled to be movable to two positions, that is, a retracted position that is not located at the image forming position, and the intermediate transfer unit is detachable from the apparatus main body only when the individual unit assembly is in the retracted position. Be composed. With these configurations, it is possible to easily replace the intermediate transfer unit, and to obtain a color image recording apparatus having an intermediate transfer belt unit that is small, simple, and easy to maintain. In particular, the stop position of the individual unit assembly when the intermediate transfer unit is attached / detached is a retracted position different from the image forming position, that is, a position shifted by a predetermined angle from the rotating member stop position at the time of image forming. , The image forming means are in a non-operation / non-contact state with each other,
When the unit is replaced, the image forming means such as the photoconductor is not rubbed or damaged.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A color image recording apparatus according to a first aspect of the present invention has an individual unit assembly in which a plurality of individual units accommodating a color toner are detachably arranged. In a color image recording apparatus for transferring an image exposed and developed on a body to recording paper via an intermediate transfer body housed in an intermediate transfer unit, the individual unit assembly is configured such that one of the individual units is an image. The intermediate transfer unit is controlled to be movable to two positions, an image forming arrangement disposed at a forming position, and a retracted arrangement in which all the individual units are not located at the image forming position. It is configured to be detachable from the apparatus main body only when it is in the retracted position. In addition, it has an individual unit assembly in which a plurality of individual units each having a color toner storage unit and a photoconductor are detachably arranged, and an image exposed and developed on the photoconductor is transferred to an intermediate transfer unit. In a color image recording apparatus for transferring to recording paper via a stored intermediate transfer body, the individual unit assembly includes an image forming arrangement in which one of the individual units is arranged in an image forming position, and all of the individual units. The unit is controlled to be movable to two positions, that is, a retracted position that is not located at the image forming position, and the intermediate transfer unit is detachable from the apparatus main body only when the individual unit assembly is in the retracted position. Be composed. Further, the following configuration may be adopted.
A color image recording apparatus according to another aspect of the present invention includes a plurality of photoconductors, each of which rotates at least, and developing means having toners of different colors, respectively, and forms a plurality of toner images of different colors on the photoconductor. Image forming unit comprising a movable image forming unit, an image forming unit group in which the plurality of image forming units are arranged, and a single exposure position and a single transfer position, wherein the image forming unit forms an image. A position, moving means for moving the entire image forming unit group in order to arrange the plurality of image forming units at the image forming position in order, and forming the toner image on the photoconductor after forming the toner image on the photoconductor. An intermediate transfer body unit including an intermediate transfer body for transferring at the transfer position of the forming position, wherein the intermediate transfer body unit is removed from the color image recording apparatus. All of the image forming unit is configured to retreat from the image forming position on Sutoki. An intermediate transfer body unit according to another aspect of the present invention includes a photoconductor that rotates at least and a developing unit that has toners of different colors, and forms toner images of different colors on the photoconductor. An image formed by a plurality of movable image forming units, an image forming unit group in which the plurality of image forming units are arranged, and a single exposure position and a single transfer position, wherein the image forming unit forms an image. Formation position,
Moving means for moving the entire image forming unit group in order to arrange the plurality of image forming units in the image forming position in order; and forming the toner image on the photoreceptor and then transferring the toner image to the image forming position. An intermediate transfer unit that integrally integrates an intermediate transfer member that transfers at a transfer position and a waste toner reservoir that collects and stores toner on the intermediate transfer member; and a fixing unit that fixes a toner image on an image receiving sheet. An intermediate transfer body unit used in a color image recording apparatus, wherein a life of a waste toner reservoir in which the waste toner reservoir of the intermediate transfer body unit is filled with waste toner is shorter than a life of the intermediate transfer body.

According to still another aspect of the present invention, there is provided an intermediate transfer member unit comprising: a developing unit having toners of different colors; a single photosensitive member; a toner image formed on the photosensitive member; An intermediate transfer body unit for use in a color image recording apparatus, comprising: an intermediate transfer body that transfers at a transfer position of the image forming position; and a waste toner reservoir that collects and stores toner on the intermediate transfer body. Body and
The waste toner reservoir is integrated with the waste toner full detector that detects the amount of waste toner stored in the waste toner reservoir.

Still another aspect of the present invention is an intermediate transfer member unit including a photosensitive member that rotates at least and developing means having toners of different colors, respectively. The image forming unit includes a plurality of movable image forming units for forming an image, an image forming unit group in which the plurality of image forming units are arranged, and a single exposure position and a single transfer position. An image forming position for forming, moving means for moving the entire image forming unit group in order to arrange the plurality of image forming units at the image forming position in order, and forming the toner image on the photoconductor. For use in a color image recording apparatus having an intermediate transfer member that transfers a toner image at a transfer position of the image forming position, and a waste toner reservoir that collects and stores toner on the intermediate transfer member. It is between transfer unit, to said intermediate transfer member, and a reservoir the waste toner, a waste toner full detector for detecting the amount of waste toner accumulated in the waste toner reservoir, integrally configure.

Still another aspect of the present invention is an intermediate transfer member unit, comprising: a photosensitive member each rotating at least; and developing means having toners of different colors. The image forming unit includes a plurality of movable image forming units for forming an image, an image forming unit group in which the plurality of image forming units are arranged, and a single exposure position and a single transfer position. An image forming position for forming, moving means for moving the entire image forming unit group in order to arrange the plurality of image forming units at the image forming position in order, and forming the toner image on the photoconductor. An intermediate transfer member that transfers the toner image at the transfer position of the image forming position; a position detector that detects the position of the intermediate transfer member; and a waste toner that collects and stores the toner on the intermediate transfer member An intermediate transfer body unit for use in a color image recording apparatus having a reservoir and a waste toner full detector for detecting an amount of waste toner stored in the waste toner reservoir, wherein the intermediate transfer body and the position detector And the waste toner reservoir and the waste toner full detector are integrated.

An outline of the present invention will be described with reference to FIG. 1 using a color electrophotographic apparatus as an example. Reference numeral 1 denotes an outer casing of the color electrophotographic printer, and a right end face side in the drawing is a front face. Reference numeral 1A denotes a printer front plate which can be freely opened and closed and raised and closed with respect to the printer outer casing 1 about a hinge shaft 1B on the lower side. The detaching operation in this open state is shown in FIG. The operation of attaching and detaching the intermediate transfer unit 2 to and from the inside of the printer and checking and maintaining the inside of the printer such as when a paper jam occurs are performed by opening the front plate 1A to open the inside of the printer. The mounting and dismounting operation of the intermediate transfer body unit 2 is designed to be in a direction perpendicular to the rotational axis generatrix direction of the photoconductor.

FIG. 3 shows the structure of the intermediate transfer unit 2. The intermediate transfer unit 2 is a unit housing 2a
An intermediate transfer member 3, a first transfer roller 4 made of a conductive elastic body, a second transfer roller 5 made of an aluminum roller, a tension roller 6 for adjusting the tension of the transfer belt, and cleaning the toner image remaining on the transfer belt. Cleaner 7, waste toner reservoirs 8a and 8b for storing collected toner, waste toner full detector 9 for detecting that the amount of toner in waste toner reservoir 8b is full, and position detection for detecting the position of the transfer belt. Vessel 10 is included. The intermediate transfer body unit 2 is detachable by opening a printer front plate 1A in FIG.

The intermediate transfer member 3 is made of an endless belt-like semiconductive urethane film having a thickness of 100 μm, and is made of a urethane foam which has been subjected to a low resistance treatment so as to have a resistance of 10 ⁷ Ωcm. It is wound around the formed first transfer roller 4, the second transfer roller 5, and the tension roller 6, and is configured to be movable in the direction of arrow Y. here,
The circumferential length of the transfer belt is a length (298 mm) in the longitudinal direction of A4 paper, which is the maximum paper size, and a length (6) slightly longer than half of the circumferential length of a photosensitive drum (diameter 30 mm) described later.
2 mm) is set to 360 mm. The cleaner 7 is a fur brush of a belt cleaner for cleaning the intermediate transfer body 3. This is a configuration in which a voltage for electrostatically attracting the toner is applied to the conductive fur. The cleaner 7 may be a rubber blade or a roller to which a voltage is applied.

FIG. 4 is a perspective view showing the structure of a position detector 10 using a photo interrupter provided inside the intermediate transfer unit 2. A detection hole 1 is provided at the end of the intermediate transfer member 3.
The position detector 10 is configured to optically detect the passage of the detection hole 12 to align the color image on the intermediate transfer member 3.

As shown in FIG. 2, the intermediate transfer unit 2
When the printer is mounted on the printer main body, the first transfer roller 4 is at a position where it does not come into contact with the photoconductor 11 (shown in FIG. 1), and the second transfer roller 5 is moved when the printer front plate 1A is closed. And the above-mentioned first through the intermediate transfer member 3.
The transfer roller 4 is pressed against a third transfer roller 19 having the same configuration as the transfer roller 4. The third transfer roller 19 is configured to be rotatable following the intermediate transfer body 3.

Referring back to FIG. Black in the center of the printer,
The four fan-shaped image forming units 13Bk, 13Y, 13M, and 13C for the respective colors of cyan, magenta, and yellow form an image forming unit group 14, 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 14 by opening the printer left face plate 1C of FIG. 1 around the hinge shaft 1D. Image forming unit 1
Reference numeral 3 designates a mechanical drive system and an electric circuit system on both the image forming unit side and the printer side which are connected via a mutual coupling member (not shown) by being properly mounted in the printer.・ Electrically integrated.

Image forming unit 1 arranged in an annular shape
3Bk, 13C, 13M, 13Y is a support (not shown)
, And is driven by a moving motor 15 as a moving means as a whole, and is fixed and does not rotate.
6 so as to be rotatable. At the time of image formation, each image forming unit can be sequentially positioned at an image forming position 17 facing the first transfer roller 4 supporting the above-described intermediate transfer body 3 by rotational movement. The image forming position 17 is also an exposure position by the laser signal light 18.

When the intermediate transfer unit 2 is mounted on the printer body and the image forming operation is started, the first transfer roller 4
Is pressed against the photoconductor 11 with a force of about 1.0 kg via the intermediate transfer member 3, and the second transfer roller 5 has the same configuration as the first transfer roller 4 via the intermediate transfer member 3. The third
It is pressed against the transfer roller 19.

FIG. 5 shows the black image forming unit 13Bk in detail. Each image forming unit is made of the same constituent members except for the developer put therein, so that the image forming unit 13Bk for black will be described to simplify the description,
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 configuration of each color, a character indicating each color is denoted by the reference numeral. In this description, it goes without saying that any developing method may be used as long as it is used in a normal electrophotographic method. In FIG. 5, reference numeral 11 denotes an organic photoreceptor in which phthalocyanine is dispersed in a polycarbonate binder resin, reference numeral 20 denotes a non-rotating magnet fixed coaxially with the photoreceptor 11, reference numeral 21 denotes a charging roller for negatively charging the photoreceptor, and reference numeral 18 denotes a laser signal. Reference numeral 22 denotes an exposure window through which the laser beam enters the image forming unit, and 23 denotes a developer hopper. In the developer hopper 23, a two-component developer 26Bk obtained by mixing a ferrite carrier 24Bk having a particle diameter of 50 μm, the surface of which is coated with a silicone resin, and a black toner 25Bk in which a black pigment is dispersed in a polyester resin is added. It is attached to the surface of the photoconductor 11. 27 is a rotatable collecting electrode roller made of aluminum, 28 is a non-rotating magnet coaxially fixed inside, 28 is a scraper made of phosphor bronze scraping toner on the collecting electrode roller, and 30 is a voltage applied to the collecting electrode roller. Is applied. Reference numeral 31 denotes a cleaner for cleaning the toner remaining on the surface of the photoconductor after transfer. The photoreceptor 11 was 30 mm in diameter and rotated in the direction of the arrow at a peripheral speed of 60 mm / s, and the recovery electrode roller 27 was 16 mm in diameter and was also rotated in the direction of the arrow at a peripheral speed of 60 mm / s.

Returning to FIG. 1, the description will be continued. Reference numeral 32 denotes a laser exposure device disposed below the inside of the printer outer casing 1, and includes a semiconductor laser, a scanner motor 32a, a polygon mirror 3
2b, a lens system 32c and the like. The pixel laser signal light 18 corresponding to the time-series electric pixel signal of the image information from the scanner unit 32 is used for the image forming unit 13B of FIG.
through the light path window 33 configured between k and 13C,
The light enters a fixed mirror 35 in the shaft 16 through a window 34 opened in a part of the shaft 16 and is reflected to form an image forming position 1.
7 enters the image forming unit 13Bk from the exposure window 22 of the image forming unit 13Bk, and passes through a passage between a developer reservoir 23 and a cleaner 31 which are disposed vertically in the image forming unit. The light enters the exposure unit on the left side of the exposure device 11 and is scanned and exposed in the generatrix direction.

Here, since the optical path from the optical path window 33 to the mirror 35 uses the gap between the adjacent image forming units 13Bk and 13C, the image forming unit group 1
4 has little wasted space. Also, mirror 3
5 is provided at the center of the image forming unit group 14, so that it can be constituted by a single fixed mirror, which is simple and easy to align.

Reference numeral 19 denotes a third transfer roller disposed inside the front plate 1A of the printer and above the feed roller 36, and a nip portion where the intermediate transfer body 3 and the third transfer roller 19 are pressed against each other is provided with a printer. A paper transport path is formed so that the paper is fed by a paper feed roller 36 provided below the front plate 1A.

Reference numerals 37a and 37b denote fixing rollers provided on the upper inside of the printer.
8 are provided. A polyimide film 39 is stretched between 37a and 37b. This film 39
Is used for the purpose of giving the gloss of a color print. 40
Reference numeral 41 denotes a backup roller provided facing the fixing roller 37a, and reference numeral 41 denotes a paper discharge tray disposed on the paper exit side. The above is the description of the main configuration of the electrophotographic apparatus of the present invention.

Next, the configuration and operation of the image forming unit 13 and the intermediate transfer unit 2 when they are replaced will be described with reference to FIG. The position of the image forming unit group 14 in FIG. 2 is different from the position of the image forming unit group 14 in FIG. In this state, the image forming unit 13Bk is not at the image forming position 17 of FIG. The state shown here indicates a state in which the magenta image forming unit 13M is replaced. At this non-operation replacement position 42, the photoconductor 11 of the image forming unit 13Bk does not face the first transfer roller 4. At the non-operational exchange position 42, the printer stops the printing operation, and by opening the printer left face plate 1C, the exchange of each image forming unit 13 can be taken out in the arrow Z direction in FIG. When replacing another image forming unit 13, the image forming unit group 14 is stopped after being rotated by 90 ° from this state. By opening the printer front plate 1A, the intermediate transfer unit 2 can be removed in the direction of the arrow X. When the intermediate transfer body unit 2 is removed in this state, the photoconductor 11 and the intermediate transfer body 3 are not strongly pressed and damaged during the removal operation, and when the intermediate transfer body unit 2 is removed outside. Also, the external light does not enter from the released printer front plate 1A, and the photoconductor 11 does not deteriorate.

As the intermediate transfer member 3 is used for a long period of time, the surface thereof gradually deteriorates due to adhesion of toner. If the belt is significantly deteriorated, the image is partially chipped or white or black stripes are generated in the image. For this reason, it is desirable to replace the intermediate transfer belt before it deteriorates and an image is affected. However, it is extremely difficult to automatically detect the deterioration of the intermediate transfer belt in the printer.
In the present invention, as shown in FIG. 3, the intermediate transfer member 3 is integrated with the waste toner reservoir 8 to form a unit, and the waste toner is simultaneously discarded when the intermediate transfer member 3 is replaced.
In such a configuration, it is preferable to design the size of the intermediate transfer belt to a small eye volume so that the waste toner reservoir is filled with the waste toner before the end of the life of the intermediate transfer belt. In this case,
Before the intermediate transfer belt is deteriorated and an image defect occurs, the waste toner full detector 9 installed inside the waste toner reservoir detects that the toner is full, and can instruct the user to replace the intermediate transfer body unit 2. . Such a configuration is not only effective for an intermediate transfer belt on which a toner image is directly formed, but is also effective for an intermediate transfer body having a configuration in which an image receiving paper is wound around.

With the above structure, the intermediate transfer belt having a complicated structure and the waste toner reservoir are unitized, so that the user can replace the entire unit before the intermediate transfer belt is deteriorated, thereby improving the maintenance and image stability. Will be excellent.

Further, since the intermediate transfer member carries an unfixed toner image or holds an image receiving paper carrying a toner layer, the surface of a position detector for detecting the rotational position of the intermediate transfer member has a toner surface. Easily contaminated. Therefore, the surface of the position detector needs to be periodically cleaned and maintained. However, in the present invention, the intermediate transfer body and the position detector are integrally configured to constitute the intermediate transfer body unit, and when the intermediate transfer body unit is replaced, all of them are replaced with new ones. This eliminates troublesome cleaning and makes the device maintenance-free.

Similarly, the waste toner full detector in the waste toner reservoir needs to be periodically cleaned to maintain accurate detection accuracy. However, in the present invention, since the intermediate transfer body and the waste toner full detector are integrally configured and all of them are replaced with new ones when the intermediate transfer body unit is replaced, such cleaning work is omitted. Equipment that does not require maintenance.

The operation of the color electrophotographic apparatus according to one embodiment of the present invention will be described below with reference to FIGS.

The printer shown in FIG. 1 is in an image forming state. The operation of the image forming unit 13Bk will be described with reference to FIG.
The photoconductor 11 was charged to −500 V by the charging roller 21. The photosensitive member 11 was irradiated with a laser signal beam 18 to form an electrostatic latent image. At this time, the exposure potential of the photoconductor is -100V.
Met. On the surface of the photoconductor 11, a two-component developer 26
Bk was deposited by magnetic force in the developer hopper 23. Next, the surface of the photoconductor 11 was passed in front of the collection electrode roller 27. When the photosensitive member 11 passes through the uncharged area, the electrode roller 2
750V0-p (peak-to-peak 1.5) superimposed on the DC voltage of +100 V by the AC high voltage power supply 30
kV) (a rectangular wave having a frequency of 3 kHz). Thereafter, when passing through the surface of the photoreceptor 11 on which the electrostatic latent image has been written and charged to -500 V, the electrode roller 27 is superposed with a DC voltage of -300 V by a high-voltage AC power supply 30 to 750 V0-p (peak-to-peak). An AC voltage (peak wave having a frequency of 3 kHz) having a peak of 1.5 kV was applied. Then, the developer on the photoconductor 11 and the toner adhering to the non-image portion were collected by the electrode roller 27, and a negative-positive toner image was left only on the image portion on the photoconductor 11. The developer and toner adhered to the electrode roller 27 rotating in the direction of the arrow were scraped off by the scraper 29, returned to the developer hopper 23 again, and used for the next image formation. Thus, the photoconductor 1
A black toner image was obtained on No. 1. Similar operations are performed for the other developing units 13C, 13M, and 13Y other than black.

Next, returning to FIG. 1, the operation of the apparatus when forming a color image will be described. The image forming unit group 14 is at the position shown in FIG. 1, and the black image forming unit 13Bk is at the image forming position 17 as shown. At this time, the photoconductor 11 is in contact with the first transfer roller 4 via the intermediate transfer body 3. By the image forming process of the image forming unit described above,
The black signal light is input to the image forming unit 13Bk by the laser exposure device 32, and an image is formed with black toner. At this time, the image forming speed of the image forming unit 13Bk (60 mm / s equal to the peripheral speed of the photoreceptor) and the moving speed of the intermediate transfer member 3 are set to be the same, and the first transfer roller is simultaneously formed with the image. By the operation of 4, the black toner image is transferred to the intermediate transfer body 3. At this time, +1 is applied to the first transfer roller 4.
A DC voltage of kV was applied. Immediately after all the black toner images have been transferred, the image forming units 13Bk, 13C,
Reference numerals 13M and 13Y denote positions where the entire image forming unit group 14 is driven by the moving motor 15 to rotate and move in the direction of arrow Q in FIG. 1, and is rotated exactly 90 degrees and the image forming unit 13C reaches the image forming position 17. Stop. During this time, the toner hopper 23 and the cleaner 31 other than the photoconductor of the image forming unit
Is located inside the rotary arc indicated by the dotted line at the tip of the photoconductor 11, so that the intermediate transfer body 3 does not come into contact with the image forming unit.

After the image forming unit 13C arrives at the image forming position 17, the laser exposure device 32 inputs a signal light to the image forming unit 13C with a cyan signal as before, and forms and transfers a cyan toner image. Done. By this time, the intermediate transfer body 3 makes one rotation, and the next cyan toner image is positionally matched 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
The transfer roller 19 and the cleaner 7 are slightly away from the intermediate transfer body 3 and are configured so as not to disturb the toner image on the transfer belt.

The same operation as described above was performed for magenta and yellow, and a color image was formed on the intermediate transfer member 3 by superimposing the four color toner images in position. After the transfer of the final yellow toner image, the four color toner images were collectively transferred to paper (not shown) fed from the paper feed cassette at the same time by the action of the third transfer roller 19.
At this time, the second transfer roller 5 is grounded, and the third transfer roller 1
9, a DC voltage of +1.5 kV was applied. The toner image transferred to the paper was fixed by fixing rollers 37a and 37b, and then discharged to a paper discharge tray 41. The transfer residual toner remaining on the intermediate transfer body 3 is cleaned by the action of the cleaner 7 and stored in the waste toner reservoir 8b in the intermediate transfer body unit 2.

When such a printing operation was repeated for about 30,000 sheets, the waste toner reservoir 8b became full, and the waste toner full detector 9 constituted by an optical sensor output a signal indicating that it was full. At this time, the intermediate transfer body 3 was in a state where it could be used for printing about 10,000 more sheets. However, the user was prompted to replace the intermediate transfer body unit 2 based on the signal from the waste toner full detector 9.

Next, the maintenance of the image forming unit 13 and the intermediate transfer unit 2 of the apparatus when the image forming unit 13 and the intermediate transfer unit 2 are replaced will be described with reference to FIG.

First, the image forming unit group 14 is rotated by the action of the moving motor 15, and the image forming unit 1 of that color is rotated.
3 (here, 13M) is moved to the position of the left-side left face plate 1C. In this state, the photoconductor 11 of the image forming unit 13 </ b> Bk is simultaneously moved by the first transfer roller 4 of the intermediate transfer unit 2.
In a non-operational exchange position 42 which does not oppose. Then, the left face plate cover 1C located on the left side of the apparatus body is opened, and the noted image forming unit 13M is taken out of the apparatus from there. 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 intermediate transfer unit 2 in a state where the waste toner reservoir 8b is full with waste toner is replaced as follows. The image forming unit group 14 is operated by the action of the moving motor 15.
Is rotated so that the photoconductor 11 of the image forming unit 13Bk
The intermediate transfer unit 2 moves to a non-operation replacement position 42 that does not face the first transfer roller 4. The user opens the front plate 1A located at the front portion of the apparatus main body, and takes out the intermediate transfer unit 2 in the arrow X direction therefrom. Next, a new intermediate transfer unit having the previously prepared position detector, waste toner full detector and the like adjusted is mounted. Therefore, after the unit is mounted, image formation can be started without any adjustment. When the new intermediate transfer body unit is mounted on the main body, the photoconductor 11 of the image forming unit 13Bk is located at the non-operation exchange position 42, so that it does not collide with the first transfer roller 4 and is not damaged. The external light from the front panel 1A does not directly hit the photoconductor 11, thereby deteriorating the photoconductor.

The above is the description of the configuration and operation of the embodiment.
In the above embodiment, a specific structure of the image forming unit is used. However, the essence and the function and effect of the present invention are also applicable to an image forming unit having a structure using a conventional developing method or a charging method. Does not change.

The operation of a color electrophotographic apparatus according to another embodiment of the present invention will be described with reference to FIGS.

The printer shown in FIG. 6 is in an image forming state. The configuration of the image forming unit group 43 is different from that of the first embodiment, and four image forming units 44 are arranged in a horizontal straight line in the order of C, M, Y, and Bk from the left. An intermediate transfer unit 45 includes an intermediate transfer member 46, a cleaner 47, a waste toner reservoir 48, a waste toner full detector 49, and a position detector 50. Reference numeral 51 denotes a laser optical system; 52, a moving motor for moving the image forming unit group 43; 53, a fixing device for fixing a toner image transferred to paper; 54, a paper discharge tray;

FIG. 6 shows a state in which a black image is formed, and the black image forming unit 44Bk is at the image forming position 56 as shown. At this time, the photosensitive member 57 is
And is in opposition contact with the first transfer roller 58.

When the printing operation was repeated about 30,000 sheets by this apparatus, the waste toner reservoir 48 became full, and the waste toner full detector 49 constituted by an optical sensor output a signal indicating that it was full. At this time, the intermediate transfer body 46 was in a state where it could still be used for printing about 10,000 sheets. However, based on the signal from the waste toner full detector 49, the user was asked to replace the intermediate transfer body unit 45. I let you know.

Next, the maintenance of the image forming unit 44 and the intermediate transfer unit 45 of this apparatus when the image forming unit 44 and the intermediate transfer unit 45 are replaced will be described with reference to FIG.

When the developer of a specific color is consumed and the image forming unit 44 is replaced, or when the intermediate transfer unit 45 is replaced.
When performing maintenance such as replacing the image forming unit, first, the image forming unit group 43 is operated by the operation of the moving motor 52.
Is moved to a non-operational exchange position 59 where the photoconductor of each image forming unit does not contact the first transfer roller 58 of the intermediate transfer unit 45 as shown in FIG. Then, a cover (not shown) located on the front side of FIG. 7 is opened from the apparatus main body, and the intermediate transfer body unit 4 is opened therefrom.
5 is taken out of the apparatus. Next, a new intermediate transfer unit adjusted in advance is mounted. As a result, image formation can be started without any adjustment or cleaning after the mounting of the intermediate transfer body unit. When the new intermediate transfer unit is mounted on the main body, the photosensitive member of the image forming unit is located at the non-operation replacement position 59, so that the photosensitive member is not damaged by colliding with the first transfer roller 58 and is released. External light from the cover did not directly impinge on the photoreceptor to degrade the photoreceptor.

The operation of the color electrophotographic apparatus according to another embodiment of the present invention will be described with reference to FIGS.

The printer shown in FIG. 8 is in an image forming state. As in the first embodiment, the configuration of the image forming unit group 60 is such that each of the image forming units 61 includes C, M, Y, and Bk around a rotation shaft 62.
Are arranged in a fan shape in this order. Reference numeral 63 denotes an intermediate transfer body unit, which includes an intermediate transfer body 64, a cleaner 65, a waste toner reservoir 66, a waste toner full detector 67, and a position detector 68. 69 is a laser optical system, 70 is a moving motor for moving the image forming unit group 60, 71 is a fixing machine for fixing a toner image transferred to paper, 72 is a paper discharge tray, 7
Reference numeral 3 denotes a paper feeding unit.

FIG. 8 shows a state in which a black image is formed, and the black image forming unit 61Bk is located at the image forming position 74 as shown. At this time, the photoconductor 75 is made of paper (not shown).
And an intermediary transfer member 64 and are in opposition to a corona transfer unit 76.

When the printing operation was repeated about 10,000 sheets by this apparatus, the waste toner reservoir 66 was full, and the waste toner full detector 67 constituted by an optical sensor output a signal indicating that the waste toner is full. At this time, the intermediate transfer member 64 was in a state where it could be used for printing about 1,000 more sheets. However, based on the signal from the waste toner full detector 67, the user was prompted to replace the intermediate transfer member unit.

Next, the maintenance of the image forming unit and the intermediate transfer unit of the apparatus at the time of replacement will be described with reference to FIG.

In the case where the developer of a specific color is consumed and the image forming unit is replaced, or when maintenance such as replacement of the intermediate transfer unit is performed, first, the image forming unit group is operated by the movement motor 70. 9, the photosensitive member of each image forming unit is moved to a non-operational replacement position 77 where the photosensitive member of each image forming unit does not contact the intermediate transfer member unit 63, as shown in FIG. Then, a cover (not shown) located on the front side in FIG. 9 is opened from the apparatus main body, and the intermediate transfer body unit 63 is taken out of the apparatus from the cover. Next, a new intermediate transfer unit adjusted in advance is mounted. Thus, after the unit is mounted, image formation can be started without any adjustment or cleaning.

When the new intermediate transfer member unit is mounted on the main body, the photosensitive member of the image forming unit is located at the non-operation exchange position 77, so that the photosensitive member and the intermediate transfer member 64 are not damaged by collision. Also, the external light from the opened cover did not directly hit the photoreceptor and did not deteriorate the photoreceptor.

The intermediate transfer body unit used here is not limited to the above-described one in which a dielectric film is formed into a cylindrical shape and paper is wound on the surface thereof, but also a rubber in which carbon is dispersed on a metal drum, for example. Needless to say, a bias transfer drum or the like having a configuration in which a conductive elastic layer such as the above is provided, and a dielectric layer for electrostatically adsorbing paper is further provided thereon.

[0058]

According to the present invention, a color image recording apparatus having a small and simple structure of the intermediate transfer section and good maintenance performance can be obtained by the above structure.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating a positional relationship during image formation of a color electrophotographic apparatus using an intermediate transfer body unit of the present invention.

FIG. 2 is a configuration diagram showing a non-operation replacement position of a color electrophotographic apparatus using the intermediate transfer body unit of the present invention.

FIG. 3 is a configuration diagram of an intermediate transfer body unit of the present invention.

FIG. 4 is a configuration diagram showing a configuration of a position detector of the intermediate transfer body unit of the present invention.

FIG. 5 is a configuration diagram showing a configuration of an image forming unit used in the color electrophotographic apparatus according to the first embodiment of the present invention.

FIG. 6 is a configuration diagram illustrating a positional relationship during image formation of a color electrophotographic apparatus using an intermediate transfer body unit according to a second embodiment of the present invention.

FIG. 7 is a configuration diagram showing a non-operation exchange position of a color electrophotographic apparatus using an intermediate transfer body unit according to a second embodiment of the present invention;

FIG. 8 is a configuration diagram showing a positional relationship during image formation of a color electrophotographic apparatus using an intermediate transfer unit according to a third embodiment of the present invention.

FIG. 9 is a configuration diagram showing a non-operation exchange position of a color electrophotographic apparatus using an intermediate transfer unit according to a third embodiment of the present invention;

FIG. 10 is a configuration diagram of a conventional color image forming apparatus.

[Explanation of symbols]

 2, 45, 63 Intermediate transfer unit 3, 46, 64 Intermediate transfer member 4 First transfer roller 5 Second transfer roller 6 Tension roller 7, 47, 65 Cleaner 8, 48, 66 Waste toner reservoir 9, 49, 67 Waste Toner full detector 10, 50, 68 Position detector 11, 57, 75 Photoconductor 19 Third transfer roller 13, 44, 61 Image forming unit 14, 43, 60 Image forming unit group 17, 56, 74 Image forming position 42 , 59, 77 Non-operational exchange position 18 Laser signal light 32 Laser exposure device 35 Mirror

Continuation of the front page (56) References JP-A-3-174559 (JP, A) JP-A-61-259282 (JP, A) JP-A-4-110871 (JP, A) JP-A-3-191368 (JP) JP-A-62-204281 (JP, A) JP-A-60-260968 (JP, A) JP-A-5-241420 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB G03G 13/01 G03G 15/01-15/01 117 G03G 15/00 550 G03G 21/16-21/18 G03G 15/16 G03G 15/08-15/095

Claims (4)

(57) [Claims] 1. An image forming apparatus comprising: an individual unit assembly in which a plurality of individual units accommodating a color toner are detachably arranged; and an image exposed and developed on a photoconductor is accommodated in an intermediate transfer unit. A color image recording apparatus that transfers the image data to recording paper via the intermediate transfer member, wherein the individual unit aggregate includes an image forming arrangement in which one of the individual units is arranged at an image forming position; The intermediate transfer unit is configured to be detachable from the apparatus main body only when the individual unit assembly is in the retracted position, the retracted position not being located at the image forming position. A color image recording apparatus, characterized in that: 2. An image forming apparatus according to claim 1, further comprising: an individual unit assembly in which a plurality of individual units each having a color toner accommodating section and a photoconductor are detachably arranged. In a color image recording apparatus that transfers to a recording sheet via an intermediate transfer body housed in a transfer unit, the individual unit assembly includes an image forming arrangement in which one of the individual units is arranged at an image forming position, A retreat arrangement in which the individual unit is not located in the image forming position, and the intermediate transfer unit is controlled from the apparatus main body only when the individual unit assembly is in the retreat arrangement. A color image recording device, which is detachably configured. 3. An individual unit assembly, wherein an individual unit having an opening for supplying the accommodated color toner to the outside of the unit is detachably mounted around an axis provided in the apparatus main body in a direction perpendicular to the axis. 3. A rotating body comprising a plurality of rotating bodies having a substantially columnar shape and being rotatable around the axis while the opening is always located on the outer peripheral side. The color image recording apparatus as described in the above. 4. The individual unit assembly according to claim 1, wherein each individual unit is arranged in parallel, and one of the individual units is selectively positioned at an image forming position by reciprocating movement. The color image recording apparatus according to claim 2.