JPS61212857A - Two-color development copying machine - Google Patents

Abstract

PURPOSE:To perform two-color development with a normal photosensitive body by using a positive light image obtained by an image processing element to write a black pattern and a negative light image by said element to write a blue light image, and aligning both light images with each other on the photosensitive body. CONSTITUTION:Two developing devices 28 and 29 of blue and black are provided along the photosensitive body 27 and toner images of two colors formed on the photosensitive body 27 are transferred to the same transfer paper 31 one over the other. In this copying machine, a BSO element 1 is positioned where original luminous flux from an image forming lens 5 forms an image and a light image read out of the element 1 travels to an exposure position on the photosensitive body 27. Then, when a two-color copy of blue and black is taken, the black part of an original is recorded and then the light image is written on the photosensitive body to form a toner image; and the blue part is written on the photosensitive body by irradiating both light images so that the negative image from the element 1 is aligned with each other on the photosensitive body 27. When the back part is written on the element 1, an exposure lamp 21 is turned on and an exposure optical system is moved for scanning. When the blue part toner image is formed, the exposure optical system is moved for scanning and when the black part toner image is formed, the exposure lamp is turned off and a scan for exposure is not made.

Description

Detailed Description of the Invention Technical Field The present invention includes an image forming process in which developing units of two different colors are arranged along a photoconductor, and each of the developing units 1 to 1 develops an image. The present invention relates to a copying machine capable of two-color development in which toner images formed on respective photoreceptors are transferred onto the same transfer paper in a superimposed manner.

A copying machine that can make two-color copies from a two-color original uses a two-layer photoreceptor to transfer latent images with different potentials and polarities to the photoreceptor, corresponding to each color of the original. By forming 42 and selectively developing each of them with a developing device of a different color,
2. Description of the Related Art Copying machines that make two-color copies compatible with two-color originals have been proposed.

The photoreceptor used in this type of two-color copying machine is completely different from the photoreceptor used in ordinary single-color copying machines, and is manufactured separately for the two-color copying machine and is used as a replacement part. Must be prepared. On the other hand, if this photoreceptor is used as a common part in a monochrome copying machine, it will be expensive in terms of manufacturing and maintenance, and many of the photoreceptors are used in Demeriso 1~. Even if the number of models of equipment such as copiers increases depending on the purpose, it is standard practice in manufacturing to reduce costs by using as many common parts as possible instead of using different parts for each model. be. When adding new functions to a copying machine, it is important to keep in mind the points in item 1-1, to use previously used parts as much as possible, and to consider common parts.

In addition, two photoreceptor drums are provided, and a beam splitting means such as a half mirror is installed in the optical path after the imaging lens of the exposure optical system, and filters of different colors can be inserted into the divided beam, and filters of different colors can be inserted into the divided beam. By changing the image process, each photoreceptor drum
A two-color copying machine is also known in which a latent image corresponding to a two-color image on a document is formed on L, a latent image of a different color is developed, and the images are superimposed and transferred onto the same transfer paper. In this case, two sets of photoreceptor and copying process equipment arranged around the photoreceptor are required, which increases the size of the apparatus and increases the cost.

Purpose The present invention is based on a completely new concept that solves the above-mentioned problems of two-color development copying machines that have been proposed in the past. The purpose of the present invention is to provide a copying machine capable of

Structure The copying machine of the present invention that achieves this object is equipped with developing units of two different colors around a single ordinary photoreceptor, has an image forming process in which each developing unit performs development, and each In a copying machine in which two-color toner images formed on a photoreceptor in the image forming process are superimposed and transferred onto the same transfer paper, an image processing element, which will be described in detail later, is used to process a document light beam emitted from an image forming lens of an exposure optical system. is formed at a position such that the optical image read out from the element faces the exposure position on the photoreceptor.

The present invention particularly relates to the process of making two-color copies corresponding to the respective colors of blue and black originals using the above-mentioned copying machine, and the driving of the copying machine in each of the processes. When this copying machine performs two-color copying from a blue-black original, a step is provided to write and record the black part pattern of the original in the image processing element, prior to the toner image forming step corresponding to both the blue and black image parts. In the step of forming a toner image corresponding to a black image, the optical image is written on the photoreceptor by writing the image stored in the image processing element, and in the step of forming a toner image corresponding to a blue image, the optical image is written on the photoreceptor. For writing, the photoreceptor is irradiated with both optical images such that the original and the negative optical image emitted from the image processing element coincide on the photoreceptor. In the step of writing the black part image of the original onto the image processing element, the exposure lamp of the copying machine is turned on and the exposure system is moved for scanning. In the step of forming a toner image for the blue part of the original, the exposure lamp is turned on and scanning movement based on exposure is performed.In the process of forming a toner image for the black part of the original, the exposure lamp is turned off and scanning is performed using the exposure light system. There will be no movement.

Adding 6 development units for two colors to a normal single-color analog copying machine means that a full-color copying machine using the color separation image superimposition transfer system can handle three to four colors of yellow, magenta, cyan, and black if necessary. Since the developing device is installed around a single photoconductor, a Mylar transfer drum is installed, and the same transfer paper wrapped around this drum is used to perform overlapping transfers, there are almost no problems with the technology. .

The image processing element used in the copying machine of the present invention has strong photoconductivity in a specific wavelength range, and emits light with an intensity corresponding to the potential when irradiated with light outside the wavelength range. It is necessary. Bj1□5jO7° (hereinafter referred to as BSO) is known as a substance having such properties. As shown in FIG. 4, the photoconductive properties of the BSO single crystal are such that the photocurrent is large at short wavelengths and small at long wavelengths.

Using this characteristic, if a black/blue two-color original is irradiated with white light or blue light and the reflected light is incident on the BSO, the blue part of the original will be exposed to the BSO in the same way as the white part of the background. death,
The black image area is not exposed, and a latent image of only the black image is formed and stored. When red light is applied to the +3 SO in which an image is stored, light corresponding to the potential can be transmitted and the stored image can be read out without changing the original exposure state.

The configuration of the 880 image processing element and its operating principle will be explained in more detail. BSO image processing device As shown in FIG. 5, parylene (polyparaxylylene) is vacuum-deposited on the surface of the BSO crystal 2 to a thickness of, for example, 5 μm to form an insulating layer 3, and a transparent conductive layer is further applied on both the front and back surfaces. It is constructed by forming a film (transparent electrode) 4.

The operating principle of the 880 image processing element 1 having this configuration will be explained step by step based on FIG. is applied, and one surface of the BSO element is uniformly irradiated with light containing short wavelength light as shown in FIG. after that(
c) Reverse the applied voltage as shown in the figure, (d) As shown in the figure,
A light image of the original is irradiated onto the other surface of the BSO element. This irradiation light is obtained by irradiating the document with white light or blue light, and the voltage distribution within the element is shown by a solid line. (d) BSO
Inside the crystal, in the light irradiated area (the area corresponding to the background area and blue image area of the original), the charges generated in the crystal move in the direction of the electric field, are trapped at the interface with the insulating layer 3, and the charges inside the crystal move in the direction of the electric field. Potential gradient decreases.

On the other hand, the potential gradient within the crystal is maintained in the unirradiated portion of the optical image (the portion corresponding to the black image, the dark portion). In this state (e)
As shown in FIG. 2, when red light is irradiated onto the crystal through a polarizer and emitted through an analyzer, the optical image of the image stored as a potential gradient is read out as a negative image. If the applied voltage V is inverted or lowered during reading, a positive image will be obtained.

In order to install the 880 image processing element in a copying machine and perform the image recording and reading operations described in "-", the 880 image processing element passes through the imaging lens of the original exposure optical system, as shown in Figure 1. The original light beam incident on the BSO element 1 is imaged,
and a lens 5 that focuses the writing beam from the element onto the surface of the photoreceptor; a light source 6 that illuminates the entire surface of the BS○ element; and a light source 6 that can be inserted into and removed from the optical path between the lens 5 and the element 1. The analyzer 7, a polarizer 8 provided in the optical path between the light source 6 and the element 1, and a red filter 9 provided in the same optical path so as to be insertable and removable are housed in a case 10 for image processing. A processing device 11 is configured. The above-mentioned lens 5 is arranged so that the inside of the case 10 is arranged so that the original light beam from the imaging lens of the exposure optical system is imaged on the element 1 during recording, and the light beam emitted from the element 1 is imaged on the photoreceptor during reading. It is said to be movable in the optical axis direction. Further, the image processing element 1 is movable in the vertical direction at a constant speed. The image processing unit 11 includes an axial drive device 12 for the lens 5,
Analyzer 7, red filter 9 position switching drive, light source 6
A power source 13 for applying a voltage between transparent electrodes on both sides of the BSO element 1, a switching circuit 15 thereof, and a drive motor 16 for turning the element 1 upside down and moving it downward are provided. Further, a reflection plate 17 is provided behind the BSO element illumination light source 6.

FIG. 2 is a diagram showing a portion of an exposure device, a photoreceptor, and its peripheral equipment of a copying machine equipped with the above-described image processing device 11.

[Image Processing Apparatus] The exposure systems other than 1 are the same as those of a normal monochrome copying machine. The reflected light passes through the first mirror 22, the second mirror 23, the third mirror 24, the lens 25, and the fourth mirror 26, which are arranged as shown in the figure, to the photoreceptors 1 to 1.
An image is formed on the ram 27L, and the photoreceptor is exposed. The exposure lamp 21 and the first mirror 22 are integrally moved parallel to the original at a speed of V.
The second and third mirrors 23 and 24 move in synchronization with this in the same direction at a speed of V/2, and the photosensitive drum 27 rotates in the direction of the arrow at a circumferential speed of V, thereby performing exposure scanning. It will be done.

The fourth mirror 26 rotates around one edge thereof, and is set at a position where the original light beam emitted from the imaging lens 25 is reflected toward the photosensitive drum 27, and at a position where it is evacuated from the optical path of the original light beam from the lens 25. It is possible to move between the release position and the release position. With the fourth mirror 26 released, the lens 2
An image processing device 11 having the above-mentioned BS'O element is installed at a position where the light beams from the five originals are incident. The image processing device 11 includes a lens 25, as shown by the solid line in FIG.
There is an axis between the writing position where the optical axis coincides with the light flux from the image processing device 11 and the writing position where the light beam emitted from the image processing device 11 enters the exposure position of the photoreceptor tram 27 as shown by the broken line in the figure. It is rotatably provided at the center.

The photoreceptor drum 27 is a photoreceptor having the same panchromatic photoreceptor layer as the photoreceptor of a general bright color copying machine, and around it, following the exposure position, is a blue developer containing a blue developer. 28
, black developer 29 containing black developer, transfer 1 spatula 11
30 are arranged. The transfer 1-ram 30 is formed into a cylindrical shape with the same outer diameter as the photoreceptor drum 27 by pasting a Mylar sheet onto an aluminum frame, similar to a full-color copying machine using a three-color separation image superimposition transfer method. tshi,
The transfer paper 131 is gripped at its leading end by a clamper and wound around it, and is rotated synchronously in the same direction at the same circumferential speed at the contact portion with the photoreceptor drum 27.

When using this device to make a copy in the same color as the original from a blue/black two-color original, (a) First, write the black pattern of the original on the B50M.

('b) Next, the photoreceptor drum is exposed to the original, and at the same time the entire image is exposed, the black pattern recorded on the BSO element is turned into a negative image so that it matches the light image from the original on the photoreceptor. The toner is irradiated to remove the charge in the black area, leaving only the latent image in the blue image area, and is developed with a blue developer to form a blue toner image, which is transferred to transfer paper on a transfer drum.

(c') Next, the black image recorded on the BSO element is inverted to a positive image and exposed by irradiating it onto the photoreceptor to form a latent image of only the black image, which is developed with a black developer and then black. A toner image is formed, and the toner image is aligned and transferred onto the transfer paper on the transfer drum to which the blue toner image has already been transferred.

Through the steps (a), (b), and (c) in Section 2 below, a blue/black copy is obtained from the blue/black original. (a).

FIG. 3(a) shows the operation of each step of (b) and (c).

This will be explained with reference to (b), (c) and FIG. In Figure 3 (
'a), (b), and (c) are the above steps (a).

Corresponds to (b) and (c).

(a) Black image writing process to BSO element Fourth mirror 2
6 and set the image processing device 1 to the writing position.

The exposure lamp 21 is turned on and the exposure system is scanned. The photosensitive drum 27 and the surrounding process equipment do not operate. Prior to this process, the BSO element of the image processing device 1 releases the red filter 9 and the analyzer 7, and turns on the BS by the power supply 14.
A voltage is applied to the O element and the light source 6 is turned on to uniformly illuminate the element surface. When writing an original image by the exposure device, the drive motor 16 moves the BSO element at a speed equal to the original scanning speed multiplied by the reduction ratio of the image written in the BSO element, and scans the BSO element 2 with the original light flux.

Since the BSO element has sensitivity on the short wavelength side, by appropriately selecting the exposure amount, the blue part of the original will be exposed to the BSO element in the same way as the white part of the background, and only the black image part will be exposed to the BSO element. recorded on the element.

In this step, the lens 5 of the image processing device 11 converts the original light beam that has passed through the imaging lens 25 of the exposure optical system into BSO
It is held at a position where the image is formed on the element.

(b) Blue image forming step on photoreceptor drum Exposure lamp 21
is turned on, the exposure optical system is scanned, and the photoconductor tram 2
7. Rotate the transfer tram 30. The fourth mirror 26 is at the reflection position, and the image processing device 11 is at the readout position. A latent image of the entire black and blue image is formed on the photoreceptor 27-1-, which is uniformly charged by a charger (not shown), by the original light flux. On the other hand, the image processing device 11 inserts an analyzer 7 and a red filter 9 into the optical path, and irradiates the BSO element 1 with the light source lamp 6 via the red filter 9 and the polarizer 8. Since the BSO element is not sensitive to red light, the recorded image will not disappear. By moving the BSO element J at the same speed as during writing, the recorded image is read out as a negative image via the analyzer 7. That is, the black image area becomes brighter, and the background area and the blue image area become darker. Therefore, by writing with the light beam from the image processing device 11 so as to overlap the latent image written by the original light beam on the photoreceptor drum 27'2, the latent image in the black portion previously formed by the document light beam is removed. , B
The charge is removed by a bright image corresponding to the black portion produced by the SO element, and only the latent image of the blue image portion remains. In this case, so that the black latent image completely overlaps with the light image from the BSO element,
It is desirable that the light beam from the 13SO is somewhat defocused on the photoreceptor.

In order to form an image of the light beam from the BSO element on the photosensitive drum 27 during writing, the lens 5 may be displaced from the reading position, or the lens 5 may be fixed to the case 10 and the image processing device 11 may be connected to the lens 5. Another lens is provided in the optical path between the photosensitive drums 27. Particularly in the latter case, due to the arrangement of the lens, the image formation position on the photoreceptor will deviate from the image formation exposure position of the original light beam, but the amount of deviation can be compensated for by the time it takes for the surface of the photoreceptor to move. By shifting the irradiation timing, images can be overlapped on the photoreceptor, so there is no problem in shifting the exposure position, and this makes the arrangement of the image processing device easier.

The latent image formed through the two-step process is developed by the blue developing device 28 to form a blue toner image, and then transferred to the transfer drum 30.
The image is transferred onto the transfer paper 3] wrapped around the transfer paper 3.

(c) Black image forming process on photoreceptor drum Exposure lamp 21
turns off, the scanning of the exposure optical system stops, and the photoreceptor drum 2
7 rotates at a predetermined circumferential speed. The image processing device 11 is placed in the reading position, the analyzer 7 and the red filter 9 are inserted into the optical path,
The polarity of the voltage applied to the BSO element 1 is reversed to that in step (b), or the voltage is lowered while keeping the same polarity, and the light source 6 irradiates the BSO element 1 at a predetermined speed. By moving with A latent image corresponding to the image is formed. In this case, pin 1 is accurately aligned with photoreceptor -1-. The latent image thus formed is transferred to the black developing device 29.
The blue toner image is developed by the transfer paper 31"- onto which the blue toner image has been transferred in the step (b), and after the transfer paper is aligned and superimposed on the transfer paper 31, the transfer paper is separated from the transfer drum 30, fixed and transferred outside the machine. It is ejected and the blue-black copy is completed.

Images recorded on the BSO element will not disappear for a certain period of time unless the entire surface is irradiated with white light or short wavelength light, so when creating multiple blue/black copies from the same blue/black original, For the second and subsequent sheets, step (a) can be omitted. After copying a predetermined number of sheets 18 = -, the red filter 9 is released and the BSO element is uniformly irradiated with white light from the light source 6 to erase the recorded images. If the amount of light is insufficient, the polarizer 8 may also be made removable so that the BSO element is irradiated with light from the light source without passing through the polarizer.

The amount of light required to write the original image on the BS○ element is greater than the amount of light needed to expose the photoreceptor drum.
It is necessary to consider making the light intensity of the original illumination lamp adjustable, or arranging another original illumination lamp for BSO writing so that it can be switched.

In addition, since the BSO element is moved downward at a predetermined speed by the drive motor 16 for scanning, when reading after recording, or when starting reading again after reading once, the BSO is used as the base. It is necessary to return it to its home position. In this return operation, the position is adjusted to star 1 for starting the next image formation, so it is necessary to provide a quick return mechanism or the like.

In addition, in the embodiment mentioned above, a two-color developing copying machine that makes blue and black copies from a blue and black original was explained.

By changing the color of the developer, you can print from blue/black originals to other two.
It is also possible to make color copies.

If other elements with different spectral photoconductivity characteristics are used, it is also possible to make two-color copies from a two-color original of chromatic colors other than blue and black.

According to the present invention, a two-color development copying machine can be configured by using the photoreceptor widely used in general single-color copying machines, as described in the United States. There are benefits not only in terms of cost and town, but also in terms of maintenance as replacement parts can be shared.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the configuration of an example of an image processing device used in the two-color developing copying machine of the present invention, and FIG. 3(a), 3(b), and 3(c) are sectional views for explaining the effect, FIG. 4 is a curve diagram showing the photoconductive characteristics of BSO crystal, and 5th
The figure is a sectional view of an image processing element using BSO, and FIG. 6 is a schematic diagram illustrating its image writing/reading operation. 1... BSO element (image processing element) 5... Lens 6... BSO irradiation light source 7... Analyzer
8...Polarizer 9...Red filter 1-0.
... Case 11 ... Image processing device 14 ... BSO voltage voltage application power source ... Exposure lamp 22, 23, 24 ... 1st. Second. Third mirror 25・
...Imaging lens 26...Fourth mirror 27...Photosensitive drum 28...Blue developer 29...Black developer 30...Transfer drum 31...Transfer paper (a) (b) (c) (d)

Claims (3)

[Claims] (1) An exposure lamp that irradiates a document with a slit, an exposure scanning optical system that forms a light image of the document irradiated by the lamp on a photoreceptor, a photoreceptor that exposes the light image of the document to the slit, and a photoreceptor that The original light flux from the two-color developing unit installed along the line and the above-mentioned exposure optical type imaging lens enters the original, and only the black pattern of the blue-black original is recorded, and the optical image of the recorded image is transferred to the photoreceptor. an image processing element provided at a position that can irradiate the exposure position of the document, and an image forming process of forming a toner image corresponding to the black image area of the original on the photoconductor, and a toner image corresponding to the blue area of the original. A copying machine capable of two-color development, in which the toner images formed in both image forming processes are superimposed and transferred onto the same transfer paper, and the toner images formed in both image forming processes are superimposed and transferred onto the same transfer paper. In the case of two-color copying, prior to the toner image forming step corresponding to both the blue and black image areas, a step is provided to write and record the black part pattern of the document on the image processing element, and toner image forming process corresponding to the black image is performed. The optical image writing on the photoreceptor in the image process is performed by writing a positive optical image of the image stored in the image processing element, and the optical image writing on the photoreceptor in the blue image corresponding toner image forming process is performed by writing the positive optical image of the image stored in the image processing element. In a copying machine that irradiates both light images onto a photoreceptor so that the negative light image emitted from the image processing element and the image processing element coincide on the photoreceptor, the process of writing the black part image of the original onto the image processing element is performed by the copying machine. A copying machine characterized in that an exposure lamp is turned on and an exposure optical system is scanned and moved. (2) In the step of forming a toner image corresponding to the blue image of the above-mentioned original, the exposure lamp of the copying machine is turned on and scanning movement based on the exposure system is performed, and in the step of forming a toner image corresponding to the black image of the above-mentioned document, copying 2. A copying machine according to claim 1, wherein an exposure lamp of the machine is turned off and scanning movement of an exposure optical system is not performed. (3) When producing a plurality of two-color copies from the same blue-black original, the above-mentioned writing step to the image processing element is omitted when producing the second and subsequent copies. Copying machine according to item 1.