JP2768983B2 - Color image processing equipment - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a color image processing system capable of black and white image processing, and more particularly to a color electrophotographic apparatus, a color facsimile, a word processor, a personal computer, and the like. The present invention relates to a color image processing device.

[Conventional technology]

In recent years, with the colorization of documents, there has been an increasing demand for copiers that can perform not only black-and-white image copying but also color copying. To make this color copying possible, not only a black developer but also a yellow developer Many color copiers equipped with a plurality of developing devices each containing a developer of magenta, magenta, and cyan are provided (for example, Japanese Patent Publication No. 59-26).
954, JP-A-62-180379, etc.).

As described above, in the color copying machine, in the black-and-white copying mode, image formation is performed using only the black developing device, and in the color copying mode, each of the yellow, magenta, and cyan is executed. A color copying process is performed by superimposing the separated images by using a developing device and, if necessary, a black developing device used in the black and white copying mode.

By the way, regarding the image quality of a black-and-white image in the black-and-white copying mode, it is considered that a gloss-free image with as little gloss as possible is most preferable from the viewpoint of eye fatigue and readability.
A black developer adjusted so that the glossiness after the fixing process is suppressed as low as possible in combination with the fixing process, that is, a black developer having a high melting temperature is used.

Conversely, as for the image quality of a color image in the color copying mode, it is preferable that the glossiness is as high as possible, since the glossiness is good and the appearance is good. Therefore, a black developer having a low melting temperature is used for color image processing.

Therefore, in order to satisfy the above two conditions for the black developer in one developer, the conventional technology (Japanese Patent Laid-Open No. Sho 62-180379) requires that
Alternatively, the melting temperature of the black developer is adjusted so as to obtain an intermediate quality between them in a color image.

In Japanese Patent Publication No. 59-26954, a single black developer is used in common, and both black-and-white images and color images are processed. In order to reduce the time required to replace each developing device in the revolver development, the developing device of the black developer is different from the other three developing devices. Separate development positions are set separately.

Further, as another conventional technique, a fixing roller in a fixing unit has a plurality of rollers, and the surface of the roller is, for example,
Teflon-based resin (Fixed with a fixing roller coated with Teflon-based resin reduces gloss and is suitable for black-and-white copy images), silicone rubber (Fixed with a fixing roller coated with silicone rubber There has also been proposed an image processing apparatus that performs image processing suitable for a black-and-white or color image by selectively using a material coated with a material having a gloss and suitable for a color copy image.

[Problems to be solved by the invention]

However, in the above-described prior art in which the melting temperature of the black developer is adjusted and used so as to obtain an intermediate quality between a black and white image and a color image, each of the black and white image and the color image is used. In other words, the gloss cannot be reduced to the minimum necessary for black-and-white images when using the above-mentioned black developer. Ensuring easiness cannot be achieved sufficiently.
Conversely, in a color image, there is a problem that the glossiness cannot be increased until the user feels that the image is vivid and looks good.

In the case where the developing device of the black developer is arranged at a position separated from the developing devices of other colors, the developer of the separated black developing device is naturally used for color image processing. Since the yellow, magenta, cyan, and black development processes cannot be performed at the same position on the photoconductor in the color image processing of the above, the development conditions are not always constant for the development of each color, and control such as switching is complicated, and image shift is complicated. May occur.

Further, in the prior art which attempts to execute image processing suitable for black-and-white or color images by selectively using a fixing roller whose surface is coated with Teflon-based resin or silicon rubber, the fixing target If the entire surface of the image is a black-and-white copy image or a color copy image such as a picture, it is possible to cope with the above-described problem, but for example, as shown in FIG. This method cannot cope with an original in which the original and color picture portions B are mixed, and there is a problem that a satisfactory image quality cannot be ensured in the same manner as described above.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and in both black and white and color image processing, an appropriate glossiness is ensured. Further, in a color image, it is an object of the present invention to realize a vividly-looking image, to simplify the switching control of the developing device according to a black-and-white image and a color image, and to avoid the occurrence of image deviation.

[Means for solving the problem]

In order to achieve the above object, the present invention provides an electrostatic latent image forming means for forming an electrostatic latent image corresponding to a plurality of color components on a photoreceptor by repeating an image forming process of charging, exposing, and developing; For the electrostatic latent images of the respective color components formed by the electrostatic latent image forming means, yellow, magenta,
A first developing device having a plurality of developing units for executing a developing process using cyan and black developers; and selectively moving the first developing device developing unit to a first developing position in a movement path of the photoconductor. And a second developing device provided at a second developing position in the moving path of the photoconductor and performing a developing process on a single-color image with a developer. To provide.

Further, the melting temperature of the black developer inside the first developing device is set lower than the melting temperature of the black developer inside the second developing device.

[Operation] The color image processing apparatus according to the present invention performs image processing on a color image by a developing device for yellow, magenta, cyan, and black developers corresponding to the color image at the first developing position, and converts the image into a black and white image. On the other hand, image processing is performed by a black developer developing device for black and white at the second developing position.

The developing units of the yellow, magenta, cyan, and black developers corresponding to the color images can be selectively moved to the first developing position.

〔Example〕

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

FIG. 1 is an explanatory view in which a color image processing apparatus according to the present invention is applied to a color copying machine.

A color copier 100 shown in FIG. 1 is used to copy image information read by the image information reading unit 135 to a transfer paper 114, and to read image information from a document (not shown). And an image information processing unit 136 that performs a series of processes.

The image information processing unit 136 includes a photosensitive belt for forming an electrostatic latent image and executing a developing process on the electrostatic latent image.
101 and a drive roller for rotating the photosensitive belt 101
And a driven roller 10 driven by the driving roller 102
3, a charger 104 for uniformly charging the surface of the photoreceptor belt 101, an optical writing unit 105 for performing an exposure process on the photoreceptor belt 101 charged by the charger 104,
At the first developing position P1 of the photoreceptor belt 101, each of the originals corresponds to R (red), G (green), and B (blue) in order to perform a color developing process on the formed electrostatic latent image. To store the Y (yellow) developer, and
A developing device 107 having an M (magenta) developer and storing a developing roller 108 and a developing device 111 storing a C (cyan) developer and having a developing roller 110 have a melting temperature of A developing unit 113 for storing a B _K (black) developer corresponding to a low color image and having a developing roller 112, wherein the plurality of developing units can be selectively moved to the first developing position P1; storage and the developing device 137, for performing black-and-white developing process on the electrostatic latent image formed in the second developing position P2 of the photoreceptor belt 101, the melting temperature is high monochrome image corresponding B _K (black) developer Then, a developing device 151 having a developing roller 150 and a transfer paper 114 loaded on a paper feeding unit and transferring a developed visual image
A paper feed roller 115 for feeding only one transfer paper 114 from a paper feed unit, a registration roller 116 for transporting the transfer paper 114 fed from the paper feed roller 115 to the transfer unit T, A transfer belt 117 for moving the transfer unit T a plurality of times for transferring the transfer paper 114 conveyed by the rollers 116 a plurality of times; a transfer drive roller 118 for rotating the transfer belt 117; A transfer driven roller 119 that is driven by a transfer drive roller 118, a contact / separation switching roller 120 that moves the transfer belt 117 up and down, and a transfer device that transfers a visible image on the photoreceptor belt 101 to the transferred transfer paper 114. 121, a transfer paper suction charger 122 for charging the transfer belt 117 from above the transfer paper 114 to electrically attract the transfer paper 114 to the surface of the transfer belt 117, and a transfer belt by the transfer paper suction charger 122. Transfer paper 114 sucked on 117 is electrically separated. A transfer sheet separating charger 123 to the transfer sheet adsorption charger 122
A static eliminator 124 for releasing the charged state on the transfer belt 117 by the transfer paper separating charger 123;
A transfer belt cleaning device 125 for cleaning the front surface of the transfer paper 114 separated from the transfer belt 117; and a path switching member 1 for changing the transport direction of the transfer paper 114 separated from the transfer belt 117.
26, a transfer paper rear end guide plate 128 for guiding the rear end of the transfer paper during a plurality of transfer processes, a cleaning device 129 for cleaning the surface of the photoreceptor belt 101 after the transfer process, and a photoreceptor. A static eliminator 130 that eliminates the charge on the belt 101 in preparation for the next copying process, a fixing device 131 that fixes the transfer image on the transfer paper 114 that has undergone the transfer process, and a transfer that is fixed and discharged by the fixing device 131 Tray 13 for holding paper 114 outside copier 100
And 2.

 The operation of the above configuration will be described.

When Color Image Processing is Executed The content of a color document is read by the image information reading unit 135, and the content is output to the optical writing unit 105 of the image information processing unit 136. The surface of the photoreceptor belt 101 in the image information processing unit 136 is neutralized by the static eliminator 130, and is uniformly charged by the charger 104. Next, drive roller 1
02 and the driven roller 103 move the photosensitive belt 101, and an exposure process is performed. In this exposure process, a semiconductor laser or the like of the optical writing unit 105 is controlled and driven, and firstly, an optical writing process based on the yellow image information is executed. An electrostatic latent image is formed.

The image information is read by, for example, three color separation lights, for example, blue, green, and red, by an image information reading unit 135, and an image calculation process is executed based on the intensity level of each color light to execute yellow, magenta, cyan, and black. For each color. Then, the photoconductor belt
For the electrostatic latent image of the yellow image formed on 101,
The yellow developing unit 107 is brought into contact with and driven by the surface of the photoreceptor belt 101 to drive the developing roller 106 to visualize the yellow image.

The transfer belt 117 switches the vertical position of the contact / separation switching roller 120 so that the transfer belt T comes into contact with the photoreceptor belt 101.

In the transfer process, the transfer belt 117 is driven in the direction of the left arrow, and then the contact / separation switching roller 120 is pressed to the upper position to bring the transfer belt 117 into contact with the photosensitive belt 101. Then, the transfer paper 114 is fed by the paper feed roller 115 at a predetermined timing, and is conveyed by the registration roller 116 at a timing so as to match the image position formed on the photosensitive belt 101.

The transferred transfer paper 114 is subjected to a charging process of a predetermined polarity by a transfer paper suction charger 122 and is brought into close contact with the transfer belt 117 so that the position of the transfer paper 114 does not shift during the transfer process.

The device is simplified by using the contact / separation switching roller 120 as a counter electrode of the transfer paper adsorption charger 122 as well.

Here, prior to the first color transfer process, the transfer belt 117 is subjected to uniform charge removal by the charge remover 124 and, at the same time, the surface of the transfer belt cleaning device 125 is also cleaned.

When the leading end of the visualized yellow image on the photosensitive belt 117 reaches the TS position, the transfer belt 117 is driven, and the leading end of the yellow image and the leading end of the transfer paper 114 reach the transfer position T. After the transfer, the transfer device 121 performs a transfer process.

Here, as the yellow image transfer process proceeds, the leading end of the transfer paper 114 separates from the transfer belt 117 and passes on the solid line position of the path switching member 126, and the transfer paper leading end guide plate 127
Proceed in the direction (dot-dash line position (134)).

After that, the transfer belt 117 is driven to rotate in the reverse direction. Prior to this reverse rotation driving, the contact / separation switching roller 120 is lowered to the lower position, and the transfer belt 117 is separated from the photosensitive belt 101. This reverse rotation drives the transfer belt 117 and the transfer paper 114.
Is quick-returned in the right arrow direction at a speed faster than the movement speed in the left arrow direction. At the time of this return, the rear end of the transfer paper 114 is separated from the transfer belt 117 and advances toward the transfer paper rear end guide plate 128. Then, the transfer paper 114 returns exactly the predetermined distance, and the transfer paper 114 is in the position indicated by the two-dot chain line (133)
, And enters a standby state for transferring the magenta image of the second color.

On the other hand, in the case of the photoreceptor belt 101, the magenta image formation of the second color has already been performed during the yellow image transfer processing of the first color. That is, an electrostatic latent image is formed by exposure by driving and controlling a semiconductor laser based on magenta image information. Next, the developing device 137 rotates, and the first developing position P
The developing device 109 is moved to 1 and the developing roller 108 of the developing device 109 is moved.
To contact and drive the surface of the photoreceptor belt 101 to develop a magenta image only in the magenta electrostatic latent image area.

When the tip of the magenta image reaches the TS position,
As in the case of the yellow image, the transfer belt 117 is moved in the left arrow direction. Simultaneously with this, or slightly later, the contact / separation switching roller 120 is pressed in the upward direction, and is brought into contact at least until the leading end of the transfer paper 114 reaches the transfer portion T point. Further, the first color yellow image and the second color magenta image are aligned on the transfer paper 114 by the position control. Thereafter, the above steps are repeated. That is, a magenta image transfer device
Transfer processing by 121, quick return of transfer paper 114, writing of cyan image information, development processing by cyan developer, transfer processing of cyan image to transfer paper, transfer paper 11
(4) Quick return, writing of black image information, development processing with the above black developer accompanying movement of the developing device 113 for storing the developer having a low melting temperature to the first development position P1, transfer paper for the black image The superposition transfer for 114 is sequentially performed.

In the black image transfer process, the path switching member 126
Is switched to the dashed line position in the figure, and the transfer paper
The transfer paper 114 advances toward the fixing device 131 while being discharged from the leading end thereof by the transfer paper separating charger 123, and the transfer belt 117 continues normal rotation even if the rear end of the transfer paper finishes the transfer. 1
The color transfer paper 114 on which the fixing process is executed by the fixing device 131 is discharged to the tray 132,
The device returns to the initial state.

When executing black and white image processing The contents of the black and white original are read by the image information reading unit 135, and the contents are read by the optical writing unit 1 of the image information processing unit 136.
Output to 05. The surface of the photoreceptor belt 101 in the image information processing unit 136 is neutralized by the static eliminator 130,
104 uniformly charges the entire surface. Next, drive roller 102
Then, the photosensitive belt 101 is moved by the driven roller 103, and the exposure process is executed. In this exposure process, a semiconductor laser or the like of the optical writing unit 105 is controlled and driven to execute an optical writing process based on image information, and an electrostatic latent image corresponding to yellow image information is formed on the surface of the photoreceptor belt 101. Form.

Thereafter, the developing device 151 is brought into contact with and driven on the surface of the photoreceptor belt 101 at the second fantasy position P2 for the electrostatic latent image of the black and white image formed on the photoreceptor belt 101, and The black developer having a low melting temperature stored in the developing roller 150 is developed into a black-and-white image by the developing roller 150.

The transfer belt 117 switches the vertical position of the contact / separation switching roller 120 so that the transfer belt T comes into contact with the photoreceptor belt 101.

In the transfer process, the transfer belt 117 is driven in the direction of the left arrow, and then the contact / separation switching roller 120 is pressed to the upper position to bring the transfer belt 117 into contact with the photosensitive belt 101. Then, the transfer paper 114 is fed by the feed roller 115 at a predetermined timing, and is conveyed by the registration rollers 116 at a timing so as to match the image position formed on the photosensitive belt 101.

The transferred transfer paper 114 is subjected to a charging process of a predetermined polarity by a transfer paper suction charger 122 and is brought into close contact with the transfer belt 117 so that the position of the transfer paper does not shift during the transfer process.

The transfer belt 117 is driven when the leading end of the visualized black and white image on the photosensitive belt 117 reaches the TS position, and the leading end of the black and white image and the leading end of the transfer paper 114 reach the transfer position T. After the transfer, the transfer device 121 performs a transfer process.

In the image transfer step, the path switching member 126 is switched to the position indicated by the one-dot chain line in the figure, and the transfer paper 114 during the transfer processing is discharged from the leading end by the transfer paper separation charger 123,
The transfer paper 114 of the black-and-white image on which the fixing process has been performed by the fixing device 131 is discharged to the tray 132,
The device returns to the initial state.

As described above, in the present invention, a black developer having a different melting temperature is selectively used in accordance with copying of a black-and-white image and a color image. On the other hand, in the case of a color image, glossy and good-looking image processing can be performed.

In the case of color image processing, since the yellow, magenta, cyan, and black developing processes are performed at the same position on the photoconductor, the positional relationship with the electrostatic latent image forming means such as charging and exposure is constant. Since the development conditions are always constant for the development of each color, control such as switching can be simplified, and the possibility of image displacement can be avoided.

Furthermore, despite the use of a total of five developing units, the number of developing positions on the photosensitive member path is two, so that miniaturization of the apparatus itself can be promoted.

〔The invention's effect〕

As described above, the color image processing apparatus according to the present invention develops the electrostatic latent image of each color component formed by the electrostatic latent image forming means with the corresponding yellow, magenta, cyan, and black developers. A first developing device having a plurality of developing units for performing processing, a moving unit for selectively moving a developing unit of the first developing device to a first developing position on a moving path of the photoconductor, A second developing device that is provided at a second developing position in a movement path of the photoconductor and executes a developing process on a black-and-white image with a black developer; and a black developing device inside the first developing device. Since the melting temperature of the developer is set lower than the melting temperature of the black developer in the second developing device, appropriate glossiness is ensured in both monochrome and color image processing, and In the image, if there an easy image reading to prevent fatigue of the eye, also in the color image,
Achieving vivid and attractive images, black and white images,
Switching control of developing units according to color images is simplified,
The occurrence of image shift can be avoided.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the structure when a color image processing apparatus according to the present invention is applied to a copying machine, and FIG. 2 shows an example of the position of a document content to point out a problem in the prior art. FIG. EXPLANATION OF SYMBOLS 100: color copier, 101: photoreceptor belt 105: optical writing unit 106, 108, 110, 112 developing roller 107, 109, 111.113 developing device 114: transfer paper, 117: transfer belt 135: image information reading Unit 136 Image processing unit 137 Developing device 150 Developing roller 151 Developing device P1 First developing position P2 Second developing position

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 13 / 01,15 / 01-117

Claims (2)

(57) [Claims] An electrostatic latent image forming means for forming an electrostatic latent image corresponding to a plurality of color components on a photosensitive member by repeating an image forming process of charging, exposing, and developing; A first developing device having a plurality of developing units for executing a developing process on the formed electrostatic latent images of the respective color components with respective yellow, magenta, cyan, and black developers; Moving means for selectively moving a developing section of the developing device to a first developing position on the moving path of the photoconductor; and a moving means provided at a second developing position on the moving path of the photoconductor. And a second developing device for performing a developing process according to (1). 2. The method according to claim 1, wherein the melting temperature of the black developer inside the first developing device is set lower than the melting temperature of the black developer inside the second developing device. A color image processing device characterized by the above-mentioned.