JPH063919A - Color electrophotographic device - Google Patents

Abstract

PURPOSE:To provide a compact electrophotographic device with a simple consti tution. CONSTITUTION:In this device, a photosensitive body and plural image forming units 8 composed of a developing means having different color toner are used. Each of the image forming units 8 can be moved up to the same image forming position. The image forming unit 8 executes the exposure of an image and the formation of the image at an image forming position 35 by an exposing means, and the formed toner image is transferred on a transfer material by an opposed transferring/carrying means 32, and the image forming unit 8 at the image forming position 35 is successively replaced, and simultaneously, the transfer material is moved back and forth by the transferring/carrying means 32, so that the toner images of each color are aligned, superimposed, and transferred on the same transfer material. A black image forming unit 8BK is arranged on a side nearest to a fixing unit. The side shape of each unit is formed in a parallelogram.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color electrophotographic apparatus applicable to a color copying machine, a color printer or the like.

[0002]

2. Description of the Related Art In a general electrophotographic method, in order to form a color image, a method of superposing a yellow toner image, a magenta toner image, a cyan toner image or a black toner image on a transfer material is adopted. As a method of superimposing the toner images on the transfer material, a transfer drum method in which the transfer material wound around a transfer drum is repeatedly carried to the same transfer position and the toner images of respective colors sequentially formed are superposed and transferred, A continuous transfer method is generally used in which image forming units are arranged side by side and toner images of respective colors are sequentially transferred to a transfer material in an overlapping manner at different transfer positions.

As an example of the color electrophotographic apparatus using the latter continuous transfer system, there is JP-A-2-16580. FIG. 7 shows a printer section which is an image forming section of a copying machine disclosed in Japanese Patent Laid-Open No. 2-16580. In this example, for image formation of four colors, four image forming units each having a photoconductor, an exposure device, and the like are arranged, and the sheet conveyed on the belt passes through the transfer portion of each photoconductor to form a toner image. Overlaid. The digital signal sent from the image reading unit is input to the printer unit and sent to the laser exposure device of each color signal, black 1Bk, cyan 1C, magenta 1M, and yellow 1Y. Four sets of image forming units 2Bk, 2C, 2M and 2Y are juxtaposed in the printer section. Since each image forming unit 2 is composed of the same constituent member, C
Units for other colors will be described, and units for other colors will be omitted. Note that the same reference numerals are given to the same portions for each color, and subscripts indicating each color are attached to the reference numerals in order to distinguish the configuration of each color. The image forming unit 2C has a photoconductor drum 3C in addition to the exposure device 1C. The photoconductor 3C includes a charger 4C, an exposure device 1C, a developing device 5C, and a transfer charger 6C.
C and the like are arranged similarly to a known electrophotographic apparatus. The photoconductor 3C uniformly charged by the charger 4C forms a latent image of a cyan image by exposure by the exposure device 1C, and develops it by the developing device 5C to form a toner image. The transfer paper (not shown) is conveyed by the transfer belt 7 and has photoconductors 3Bk, 3C, and 3 formed with color toner images, respectively.
The toner images are sequentially transferred to M and 3Y, and the toner image is transferred by the action of the transfer device 6. In this way, a full-color image is obtained on the transfer paper.

Furthermore, in USP 495048,
As another method of forming a color image by superimposing toner images of different colors on a transfer material, a method is disclosed in which the transfer material is reciprocally moved with respect to the photoconductor to repeat the transfer and superimpose the toner images.

[0005]

Problems to be Solved by the Invention
The continuous transfer method disclosed in Japanese Patent No. 16580 requires an image forming position corresponding to the number of colors, and therefore requires an exposing unit for image-exposing a photoconductor for the number of colors, which makes the apparatus expensive. Further, with this configuration, as illustrated in Japanese Patent Laid-Open No. 1-250970, high precision is required for each color registration of the exposure apparatus, and the image exposure system requires special devise and complicated configuration. There is also the problem that there are. Furthermore, since there are a plurality of image forming positions separately, it is difficult to align the respective colors on the transfer material, and in addition to the difficulty in aligning the exposure device as described above, the color shift easily occurs. There is also a problem.

Further, in the example of reciprocating the transfer material disclosed in US Pat. No. 4,905,048 to form a color image, since the toner images of respective colors are sequentially formed by using the same photoconductor, 1) the photoconductor shape is large. However, there is a problem that 2) the structure and control for separating and contacting the transfer material with the photoconductor when moving the transfer material backward is complicated, and 3) the structure and control for separating and contacting each color developing device with the photoconductor are complicated. .

In view of the above problems, the object of the present invention is to eliminate the need for a complicated structure for aligning the image exposure system, to accurately align each color, and to increase the capacity of the developer reservoir of each image forming unit. However, it is an object of the present invention to provide an excellent color electrophotographic apparatus having a small and simple structure as a whole, and having a simple structure of an image forming unit including a photoconductor and a developing device and being easy to replace.

[0008]

In order to achieve the above-mentioned object, the present invention comprises a rotating photoconductor and developing means having toners of different colors, and different colors are provided on the photoconductor. Transfer conveying means including a plurality of movable image forming means for forming the toner image and a transfer means for carrying the transfer material to reciprocate and transferring the toner image on the photoconductor onto the transfer material at the same transfer position. And an exposure unit for performing image exposure at the same exposure position corresponding to the transfer position, and a plurality of image forming units arranged side by side in the horizontal direction, and corresponding to the transfer position and the image forming position corresponding to the exposure position. And a moving means for sequentially moving each of the plurality of image forming means, to form a color image by superimposing toner images of different colors on the transfer material, and fix it on the transfer material by a heat fixing device. A photographic device A color electrophotographic apparatus, characterized in that the arrangement order of the plurality of image forming means for placing the image forming means black most position fixing-side in the horizontal direction.

Further, according to the present invention, a rotating photoconductor, a charging device for charging the photoconductor, toner of different colors, a developer reservoir for accumulating the toner, and a developing device for developing the photoconductor with the toner. And a cleaner for cleaning the photoconductor, a plurality of image forming means for forming toner images of different colors on the photoconductor, and a reciprocating carrier carrying a transfer material and at the same transfer position. A transfer conveyance unit including a transfer unit that transfers the upper toner image onto a transfer material, an exposure unit that exposes an image at the same exposure position corresponding to the transfer position, and a plurality of image forming units that are arranged side by side in the horizontal direction. And a moving unit that sequentially moves each of the plurality of image forming units to an image forming position that corresponds to the transfer position and that corresponds to the exposure position, and superimposes and transfers the toner images of different colors onto the transfer material. Color image formation, A color electrophotographic apparatus for obtaining a color image on a copying material, characterized in that a part of a developer reservoir of an image forming means utilizes a space above a charger of an adjacent image forming means. It is a color electrophotographic device.

Further, according to the present invention, a rotating photoconductor, a charger for charging the photoconductor, and toners of different colors are provided.
A plurality of image forming means for forming a toner image of a different color on the photoconductor, comprising a developer reservoir for storing the toner, a developing device for developing the photoconductor with the toner, and a cleaner for cleaning the photoconductor. And a transfer conveyer that carries a transfer material, reciprocates, and transfers the toner image on the photoconductor onto the transfer material at the same transfer position, and an image at the same exposure position corresponding to the transfer position. Exposure means for exposing,
A plurality of image forming means are arranged adjacent to each other in the horizontal direction and have a moving means for sequentially moving each of the plurality of image forming means to an image forming position corresponding to a transfer position and an exposure position. A color electrophotographic apparatus for obtaining a color image on a transfer material by superposing and transferring toner images of different colors on a material, wherein a part of a developer reservoir of an image forming means is an adjacent image. The color electrophotographic apparatus is characterized in that the space above the cleaner of the forming means is used.

Furthermore, the present invention comprises a rotating photosensitive member and developing means having toners of different colors, respectively, and a plurality of movable members for forming toner images of different colors on the photosensitive member. An image forming unit, a transfer conveyance unit that carries a transfer material, reciprocates, and includes a transfer unit that transfers the toner image on the photoconductor to the transfer material at the same transfer position, and the same exposure corresponding to the transfer position. A plurality of image forming means are arranged side by side in the horizontal direction adjacent to each other, and the plurality of image forming means are sequentially moved to the image forming positions corresponding to the transfer position and the exposure position. A color electrophotographic apparatus, which has a moving means, forms a color image by superposing and transferring toner images of different colors on a transfer material and obtains a color image on the transfer material. Each alone A color electrophotographic apparatus which is a shape that can be extracted in order upward.

[0012]

According to the present invention, a color image is formed on a transfer paper electrostatically attracted to a transfer belt having a relatively simple structure without using a transfer unit having a complicated structure such as a conventional transfer drum. By performing the formation, it is possible to improve the reliability of paper conveyance with a simple device configuration.

Further, as compared with the continuous transfer device having four image forming positions, since the image formation for each color is performed at the same position, the structure of the exposure device and the like can be simplified and the color image can be accurately aligned.

Further, when the developing device and the photoconductor are brought into contact with each other, the problem of toner or developer scattering easily occurs. However, in the present invention, since the image forming means constitutes an independent image forming unit for each color, There is an advantage that troubles such as toner spills are unlikely to occur when moving each color unit to the image forming position.

Further, even in a color electrophotographic apparatus, black alone is most often used for printing a document, but at this time, as shown in FIG. 1, four image forming units are arranged at the leftmost end of the image forming units. When the black unit is placed, the other color unit is left at a position away from the heat source, the fixing unit, during that time, so even if many sheets are printed for a long period of time, the other color units are affected by the heat and troubles such as toner coagulation occur. Can be avoided.

Further, in general use, black alone is most frequently used. Therefore, if the black image forming unit is arranged at the image forming position while waiting for the image forming operation, the other color units are used as described above. Not only can it be protected from troubles due to heat, but the time until the start of printing operation can be shortened. As a result, when the color electrophotographic apparatus of the present invention is used alone in black, it is possible to obtain performance comparable to that of a general black and white electrophotographic apparatus.

Normally, the space above the charger is not used at all and becomes a useless space. However, if it is used as a space for storing the developer of an adjacent image forming unit, when four units are arranged side by side. The space can be used to the maximum extent without changing the size of the unit group as a whole. At this time,
If each image forming unit has a side surface shape that can be drawn out obliquely upward, for example, a parallelogram shape, only one image forming unit can be drawn out independently from a group of four image forming units. This produces a very good effect on maintainability when the image forming means is replaced for each color.

[0018]

EXAMPLES Zinc oxide, selenium, cadmium sulfide, amorphous silicon, and organic photoconductors using phthalocyanine and azo pigments can be used for the photoconductor used in the present invention.

In the present invention, a two-component developer comprising toner and magnetic carrier can be used. The toner used in the present invention is obtained by dispersing a color pigment such as carbon black or phthalocyanine in a binder resin such as an acrylic resin or a polyester resin, pulverizing and classifying. The toner may be a powder obtained by spray drying, or a powder chemically synthesized by a pearl polymerization method, an emulsion polymerization method, or the like. Further, the toner particles may be directly mixed with the carrier, or silica particles or fluororesin fine powder may be adhered to the surface of the toner and then mixed. The average particle diameter of the toner used is preferably 15 μm or less, but if it is 12 μm or less, a sharper image can be obtained. The carrier used in the present invention is a magnetic substance such as iron powder or ferrite powder, or a powder whose surface is coated with a resin, or a fine powder such as ferrite powder or magnetite.
A magnetic powder, etc., which is dispersed and mixed in a styrene resin, an epoxy resin, a styrene acrylic resin, etc. in a proportion of about 0 to 80% and pulverized and classified, is used. The average particle size of the carrier is 300
The thickness is preferably not more than μm, but particularly 150 μm or less allows the toner to be uniformly charged.

Since the image forming units used in the present invention are made of the same constituent members except the developer contained therein, the image forming unit for magenta will be described and the other colors will be omitted for simplification of description. . Note that, for each color, the same portions are denoted by the same reference numerals, and when it is necessary to distinguish the configurations of the respective colors, the letters indicating the respective colors are attached to the reference numerals. 2 to 5, the magenta image forming unit 8M is shown in detail. In each figure, the positions of the image forming units adjacent to each other are indicated by broken lines.

In FIG. 2, 9 is a drum-shaped organic photoconductor as a photoconductor in which phthalocyanine is dispersed in a polycarbonate binder resin, 10 is a magnet fixed coaxially with the axis of the photoconductor 9, and 11 is a photoconductor. A negatively charged corona charger, 12 is a grid electrode for controlling the charging potential of the photoconductor, 13 is a laser beam scanning light, and 14 is a developer reservoir. A two-component developer 17M, which is a mixture of an iron powder carrier 15M having a particle diameter of 100 μm and a toner 16M, whose surface is coated with a silicone resin, is placed in the developer reservoir 14 and attached to the surface of the photoconductor 9 by the magnetic force of the magnet 10. . The toner used is a polyester resin in which a pigment is dispersed and an additive is further added. Reference numeral 18 is a toner regulation blade made of magnetic stainless steel, 19 is a developer collecting electrode roller made of aluminum, 20 is an AC high voltage power source for applying a voltage to the developer collecting electrode roller, and 21 is a toner scraping toner on the developer collecting electrode roller. It is a scraper made of polyester film. Reference numeral 22 is a cleaner for cleaning the toner remaining on the surface of the photoconductor after the transfer. The magnetic flux density on the surface of the photoconductor 9 is 800 gauss at the maximum position. The diameter of the photoconductor 9 is 30 mm
Then, it was rotated at a peripheral speed of 120 mm / s. This unit has an advantage that each unit can be pulled out in the direction of arrow A when four units are lined up, but the upper space B of the charger 11 and the cleaner 22 shown by the chain double-dashed line cannot be effectively used. There are drawbacks.

Another improved imaging unit which can likewise be used for imaging is shown in FIG. In FIG. 3, 2
Reference numeral 3 denotes a developer reservoir having a configuration in which a space is effectively used in consideration of the shapes of adjacent image forming units. In this image forming unit, the capacity of the developer reservoir can be made about 1.5 times larger than that of the unit shown in FIG. However, when replacing the single image forming unit 8M, the arrow C in FIG.
In the direction of and also in the direction of arrow D, it cannot be removed because it hits an adjacent image forming unit. For example, of the four image forming units arranged side by side, when the image forming unit arranged on the rightmost side is pulled out upward, there is a drawback that all the adjoining left side units must be pulled out before it can be taken out. Therefore, at this time, there is a restriction on the apparatus design that the image forming unit must be pulled out in the front direction of the drawing.

FIG. 4 shows an image forming unit in which the problems of the image forming unit shown in FIG. 3 are improved. In FIG.
Reference numeral 24 is for effectively utilizing the upper space of the charger and cleaner of the adjacent image forming unit as a developer reservoir, and considering the ease of taking out the image forming unit alone. In this image forming unit, the capacity of the developer reservoir can be increased, and even when four units are arranged, it is possible to take out the image forming unit alone in the direction of arrow E in FIG. The configuration of this image forming unit will be described. Inside the developer reservoir 24, an iron powder carrier 15 having a particle size of 100 μm, the surface of which is coated with a silicone resin.
A two-component developer 17M, which is a mixture of M and toner 16M, is added and attached to the surface of the photoconductor 9 by the magnetic force of the fixed magnet 10. The toner used is a polyester resin in which a pigment is dispersed and an additive is further added. Reference numeral 25 is a developer collecting electrode roller made of aluminum, and 26 is a magnet fixed inside the developer collecting roller. Reference numeral 20 is an AC high-voltage power supply that applies a voltage to the developer collecting electrode roller, and 21 is a scraper made of a polyester film that scrapes off the toner on the developer collecting electrode roller. Reference numeral 22 is a cleaner for cleaning the toner remaining on the surface of the photoconductor after the transfer.

Yet another imaging unit is shown in FIG.
This uses a magnetic brush developing method which is generally used in a conventional electrophotographic apparatus for a developing device. In FIG. 5, reference numeral 24 is a developer reservoir that effectively utilizes the upper space of the charger and cleaner of the adjacent image forming unit. In this image forming unit, the capacity of the developer reservoir can be increased, and even when four units are arranged side by side, the image forming unit can be taken out independently in the direction of arrow E in FIG.
The configuration of this unit will be described. Inside the developer reservoir 24, the surface is coated with silicone resin, and the particle size is 100 μm.
The two-component developer 17M in which the iron powder carrier 15M and the toner 16M are mixed is put into a developing roller 28 having a magnet 27 inside, and a developer layer is formed by a developer layer thickness regulating member 29 so that the photoreceptor 9 is formed. develop. Reference numeral 30 is a high-voltage power supply that applies a voltage to the developing roller.

(Embodiment 1) A color electrophotographic apparatus according to a first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a printer section for forming an image in a color electrophotographic apparatus of the present invention.

First, in the printer section, four sets of image forming units 8Bk, 8C, 8M and 8Y as image forming means for black, cyan, magenta and yellow are arranged in parallel in this order. Here, each image forming unit used the structure shown in FIG. The operation of each image forming unit will be described with reference to FIG. The photoconductor 9 is charged with a corona charger 11 (applied voltage −5 k
V, the voltage of the grid 12 -500 V), and -500
It was charged to V. Laser beam scanning light 1 is applied to the photosensitive member 9.
3 was irradiated to form an electrostatic latent image. At this time, the exposure potential of the photoconductor was -100V. When the photoconductor 9 on which the electrostatic latent image is formed is passed through the developer 17M as described above, the developer 17 is attracted to the magnet 10 inside the photoconductor and then the internal magnet 26 of the developer collecting electrode roller 25. It was collected by the developer collecting electrode roller 25 by the magnetic force. The developer collecting electrode roller 25 is supplied with a high voltage power source 20 of -300V.
An AC voltage (frequency: 1 kHz) of 400 V 0-p (peak-to-peak 800 V) superposed with the DC voltage was applied. As a result, the toner on the photoconductor 9 moves while moving between the photoconductor 9 and the developer collecting electrode roller 25 while receiving an electrostatic force and a magnetic force at the same time. The statue remains. The toner adhering to the developer collecting electrode roller 25 was scraped off by the scraper 21 and returned to the developer reservoir 24 for use in the next image formation. Thus, a magenta toner image was obtained on the photoconductor 9. Developing devices other than magenta 8Bk, 8C, 8Y
Also has the same configuration, and the same operation is performed.

The configuration of the printer section will be described again with reference to FIG. The image forming unit as a whole is driven by a moving motor 31 which is a moving unit and can move in the horizontal direction, and each image forming unit faces the transfer portion 34 of the transfer / conveying belt 32, which is slightly pushed up by the belt regulating member 33. Image forming position 35. In the image forming units 8Bk, 8C, 8M, and 8Y that are arranged side by side, the black unit 8Bk is arranged at the image forming position as in the state of FIG.

A laser exposure device 36 generates a laser beam scanning light 13 which is modulated by a signal input to the printer section, which is reflected by mirrors 37 and 38 to generate a first laser beam.
The photosensitive member of the image forming unit at the image forming position 35 is irradiated to form a latent image. In the state of FIG. 1, it acts on the black image forming unit 8Bk.

Reference numeral 32 is a transfer / conveyance belt, which is made of an endless belt-shaped polyester film having a thickness of 100 μm.
The drive roller 39 and the roller 40 are wound around, and the transfer paper is adsorbed on the surface of the drive roller 39 and the roller 40 to be reciprocally movable. Here, in the present embodiment, the distance between the drive roller 39 and the roller 40 is set to a distance (470 mm) longer than twice the length (210 mm) of the A4 sheet in the widthwise direction. At the right end of the transfer / conveyance belt, an adsorption charger 42 for adsorbing the paper sent from the paper feed unit 41 to the transfer / conveyance belt is provided, the transfer charger 35 at the transfer part 35, and the transfer / conveyor at the left end. A static eliminator 45 for erasing static electricity on the sheet peeled from the belt and sent to the fixing device 44 is arranged. A discharge roller 46 discharges the sheet after fixing.

In this embodiment, the transfer / conveying belt is made of an insulating polyester film, but it may be made of a film made of a semiconductive material in which carbon or the like is dispersed in polyester, urethane or the like. In this case, the electric charges at the time of charging are less likely to be accumulated on the transfer / conveying belt, so that the overlapping transfer can be more easily performed.

When the paper is jammed in the apparatus and needs to be removed, the four image forming units are moved to the right end (the state shown in the drawing) when the paper is jammed at the F portion of FIG. 1, and when the paper is jammed at the G portion. It may be moved to the left end and processed. The above is the description of the main configuration of the electrophotographic apparatus of the present invention.

Next, the operation of this apparatus when forming a color image of A4 size will be described. A4 paper (not shown) is fed in the lateral direction from the paper feed unit 41, and is attracted to the transfer / transport belt 32 by the action of the adsorption charger 42 and placed on the transfer / transport belt to form an image in the image forming unit. Move to the left (hereinafter referred to as forward direction) at the same speed. At this time, the paper is surely adsorbed to the transfer / transport belt 32. Therefore, even if the transfer / transport belt is reciprocally moved as described later, the positions of the transfer / transport belt and the paper are not displaced from each other, and when the toner images of respective colors are superposed, the position Easy to match.

First, the image forming unit is at the position shown in FIG. 1, and the black image forming unit 8Bk is at the image forming position 3
It faces the transfer portion 34 at 5. From the right side of the figure, adjust the timing of the paper carried on the transfer / conveyance belt 32,
Black signal light is input to the image forming unit 8Bk by the laser exposure device 36, and an image is formed with black toner.
At this time, the image forming speed of the image forming unit 8Bk (equal to the peripheral speed of the photoconductor) and the moving speed of the transfer / conveying belt are set to be the same. The black toner image is transferred onto the transfer paper by the action of the transfer charger 43. Immediately after all the black toner images have been transferred and the trailing edge of the paper has passed the transfer portion, the transfer conveyance belt 32 is temporarily stopped and then moved in the direction opposite to the previous direction (hereinafter referred to as the reverse direction). Move at a speed greater than the forward movement speed. At this time, the leading edge of the paper is the transfer / conveyor belt
Since the length of 2 is sufficiently long, it stops before the drive roller 39 and is not separated from the transfer / conveying belt.

On the other hand, almost simultaneously with the start of the reverse movement of the transfer / conveying belt, the image forming unit groups 8Bk, 8C, 8M and 8 are formed.
The entire Y is driven by the moving motor 31 and integrally moves to the left in FIG. At this time, immediately after the sheet moves in the reverse direction and the rear end of the sheet passes the transfer portion 34, the reverse direction moving speed of the transfer / conveying belt 32 and the image formation are performed so that the image forming unit 8C reaches the image forming position 35. Set the movement time of the unit. The trailing edge of the paper passes the transfer portion 34 to the right,
After the image forming unit 8C reaches the image forming position 35, the transfer / conveying belt 32 is again moved in the forward direction at a constant speed. As before, this time the laser exposure device 36 inputs a cyan signal to the image forming unit 8C and the formation and transfer of a cyan toner image is performed. At this time, the start of the movement of the transfer / transport belt 32 is controlled so that the black toner image on the paper and the next cyan toner image are positionally aligned with the start of the writing of the signal light.

The above operation is similarly performed for magenta and yellow, and four color toner images are positionally aligned on the transfer paper to form a superimposed color image. After the last transfer of the yellow toner image, the transfer / conveying belt 32 is moved forward as it is, and the transfer paper on which the color image is formed is separated from the transfer / conveying belt 32 while being neutralized by the static eliminator 45, and further fixed. The toner image is fixed by 44, and finally discharged through the discharge roller 46 to the outside of the apparatus.

The drive roller 3 of the transfer / conveyance belt 32 is used.
The distance between the roller 9 and the roller 40 is shown in FIG.
Is set to be larger than 7/4 of the total length of the image forming units in the horizontal direction. Therefore, even if the image forming unit group moves integrally until each of the image forming units reaches the image forming position, the adsorption charger It does not hit 42 and the static eliminator 45. The above is the description of the operation of the electrophotographic apparatus of this embodiment in the A4 color mode.

Next, the operation in the monochromatic mode will be described. In the single color mode, the image forming unit of a predetermined color is first moved to the image forming position 35 before the transfer sheet reaches the transfer position. Next, image formation and transfer of a predetermined color are performed in the same manner as before, and this time, even after transfer, the transfer / conveyance belt 32 is directly used.
Continue to move in the forward direction to settle. Therefore, the feature of the color electrophotographic apparatus of the present invention is that it is possible to use, for example, A3 size paper of A4 size or more in the single color mode.

The above is the description of the configuration and operation of the first embodiment. (Embodiment 2) Another embodiment will be described with reference to FIG.
The configuration of the image forming unit is different from that of the first embodiment. The printer unit includes image forming units 8Bk, 8C, 8M as four sets of image forming means for each color of black, cyan, magenta, and yellow.
8Ys are arranged side by side. The image forming unit used the configuration of FIG. The operation will be described below with reference to FIG.
The photoconductor 9 was charged to −500V by a corona charger 11 (applied voltage −5 kV, grid 12 voltage −500V). The photoconductor 9 was irradiated with laser beam scanning light 13 to form an electrostatic latent image. This electrostatic latent image was developed by the developing roller 28 carrying M developer 17M. At this time, a DC voltage of −400 V was applied to the developing roller 28 by the high voltage power source 30. Developing devices other than magenta 8Bk, 8C, 8Y
Also has the same configuration, and the same operation is performed.

The configuration of the printer unit will be described again with reference to FIG. Image forming units 8B arranged side by side
The k, 8C, 8M, and 8Y are driven by a moving motor 31 that is a moving unit as a whole and can be moved in the lateral direction.
Thus, it can be located at the image forming position 35 opposed to the slightly pushed up transfer portion 34. Other configurations are shown in FIG.
The configuration is the same as that of.

A4 paper is fed in the lateral direction from the paper feeding section 41, and the transfer / conveying belt 32 is operated by the action of the adsorption charger 42.
While being adsorbed on the transfer conveyor belt, the transfer conveyor belt is moved in the forward direction at a constant speed. First, the image forming unit 8B for black
k is placed at the image forming position 35 and is opposed to the transfer portion 34. From the right side of the figure, the laser exposure device 36 inputs the black signal light to the image forming unit 8Bk at the same timing of the sheet carried on the transfer / conveying belt 32, and the image formation is performed with black toner. Immediately after all the black toner images have been transferred and the trailing edge of the paper has passed the transfer portion, the transfer / conveyance belt 32 is temporarily stopped and then moved in the opposite direction. On the other hand, the image forming unit groups 8Bk, 8C, 8M, and 8Y are entirely driven by the moving motor 31 and move integrally to the left in FIG. Next, a cyan signal is input to the image forming unit 8C to form and transfer a cyan toner image. The same operation is performed for magenta and yellow, and four color toner images are superimposed on the paper to obtain a color image. After the transfer of the last yellow toner image, the transfer / transport belt 32 is moved in the forward direction as it is, and is fixed by the fixing device 44. The above is the description of the configuration and operation of the color electrophotographic apparatus of the second embodiment.

[0041]

As described above, according to the present invention, since the images of the respective colors are formed at the same image forming position without using a transfer drum having a complicated structure, the simple configuration allows accurate color registration. The image forming means is completed independently as one image forming means for each color, so that the configuration is simple and the image forming means can be easily replaced for each color. Will also be excellent.

Further, while the capacity of the developer reservoir of each image forming unit is increased, the overall structure is kept small and simple, and the structure of the image forming unit including the photoconductor and the developing device is simple and easy to replace. An excellent color electrophotographic device can be obtained.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram of an image forming unit used in the present invention.

FIG. 3 is a configuration diagram of an image forming unit used in the present invention.

FIG. 4 is a configuration diagram of an image forming unit used in the first embodiment of the present invention.

FIG. 5 is a configuration diagram of an image forming unit used in a second embodiment of the present invention.

FIG. 6 is a configuration diagram of a color electrophotographic apparatus according to a second embodiment of the present invention.

FIG. 7 is a schematic view of a conventional color electrophotographic apparatus.

[Explanation of symbols]

 8 Image Forming Unit 9 Photoreceptor 10 Magnet 11 Corona Charger 13 Laser Exposure 14/24 Developer Reservoir 25 Electrode Roller 20/30 High Voltage Power Supply 32 Transfer Conveying Belt 31 Unit Moving Means 35 Image Forming Position

Claims (6)

[Claims] 1. A plurality of movable image forming means, each of which comprises a rotating photoconductor and a developing means having a different color toner, and which forms a toner image of a different color on the photoconductor. A transfer conveyance unit that carries a transfer material, reciprocates, and has a transfer unit that transfers the toner image on the photoconductor onto the transfer material at the same transfer position; and the same exposure position corresponding to the transfer position. Exposure means for performing image exposure with the image forming means, and the plurality of image forming means are arranged adjacent to each other in the horizontal direction, and each of the plurality of image forming means is provided at an image forming position corresponding to the transfer position and corresponding to the exposure position. And a moving means for sequentially moving the same to the same exposure position to form a color image by superposing toner images of different colors on the transfer material, and fixing the color image on the transfer material by a heat fixing device. And Thus, the color electrophotographic apparatus is characterized in that the image forming means in which the plurality of image forming means are arranged in black is arranged at the position closest to the fixing device in the horizontal direction. 2. The color electrophotographic apparatus according to claim 1, wherein the black image forming means is positioned at the image forming position when the image forming operation of the color electrophotographic apparatus is on standby. 3. A rotating photoconductor, a charger for charging the photoconductor, toners of different colors, a developer reservoir for accumulating the toner, and a developing device for developing the photoconductor with the toner. A cleaner for cleaning the photoconductor,
A plurality of image forming means for forming toner images of different colors on the photoconductor, and a reciprocating carrier carrying a transfer material, and transferring the toner image on the photoconductor to the transfer material at the same transfer position. A transfer transporting unit including a transfer unit, an exposing unit that performs image exposure at the same exposure position corresponding to the transferring position, and the plurality of image forming units are arranged side by side in the horizontal direction.
A transfer unit that sequentially moves each of the plurality of image forming units to an image forming position that corresponds to the transfer position and that corresponds to the exposure position, and superimposes toner images of different colors on the transfer material. A color electrophotographic apparatus for transferring and forming a color image to obtain a color image on the transfer material, wherein a part of a developer reservoir of the image forming means is a space above the charger of an adjacent image forming means. A color electrophotographic apparatus, characterized in that it is configured to utilize 4. A rotating photoconductor, a charger for charging the photoconductor, toners of different colors, a developer reservoir for accumulating the toner, and a developing device for developing the photoconductor with the toner. A cleaner for cleaning the photoconductor,
A plurality of image forming means for forming toner images of different colors on the photoconductor, and a reciprocating carrier carrying a transfer material, and transferring the toner image on the photoconductor to the transfer material at the same transfer position. A transfer transporting unit including a transfer unit, an exposing unit that performs image exposure at the same exposure position corresponding to the transferring position, and the plurality of image forming units are arranged side by side in the horizontal direction.
A transfer unit that sequentially moves each of the plurality of image forming units to an image forming position that corresponds to the transfer position and that corresponds to the exposure position, and superimposes toner images of different colors on the transfer material. A color electrophotographic apparatus for transferring and forming a color image to obtain a color image on the transfer material, wherein a part of the developer reservoir of the image forming means is located above the cleaner of the adjacent image forming means. A color electrophotographic apparatus characterized by being used. 5. A plurality of movable image forming means for forming a toner image of a different color on the photosensitive body, each photosensitive body having a rotating photosensitive body and a developing means having a different color toner. A transfer conveyance unit that carries a transfer material, reciprocates, and has a transfer unit that transfers the toner image on the photoconductor onto the transfer material at the same transfer position; and the same exposure position corresponding to the transfer position. An exposing means for performing image exposure with, and the plurality of image forming means are juxtaposed side by side in the horizontal direction,
A transfer unit that sequentially moves each of the plurality of image forming units to an image forming position that corresponds to the transfer position and that corresponds to the exposure position, and superimposes toner images of different colors on the transfer material. A color electrophotographic apparatus for transferring and forming a color image to obtain a color image on the transfer material, wherein the adjoining image forming means has a shape that can be independently taken out obliquely upward. Photographic equipment. 6. A color electrophotographic apparatus according to claim 4, wherein the side surface of the image forming means is a substantially parallelogram.