JPS63198082A - Duplex copying machine for black/white and color - Google Patents

Abstract

PURPOSE:To obtain a full color copy, a monocolor copy and a multicolor copy by an original scan of once, by providing an optical system which can switch a color separation optical path and an optical path forming an image on the respective photosensitive body belts by the optical path length being equal to the color separation optical path. CONSTITUTION:A 12-th mirror 201 and a 14-th mirror 203 are half mirrors, and fixed between the 9-th mirror 101 and the 10-th mirror 102, and a 13-th mirror 202 and a 15-th mirror 204 are total reflection mirrors, and provided so as to be switchable to a position which does not obstruct an optical path from the 8-th mirror 18 and a 7-th mirror 17, and a position reflecting a luminous flux from the 12-th mirror 201 and the 14-th mirror 203, in the intermediate part of a third photosensitive body belt 53'', the second photosensitive body belt 53' and its exposure and projection positions 23, 22, and a 8-th mirror 18 and the 7-th mirror 17, respectively, and these mirrors are installed so that the optical path length becomes the same as that of the time of a full color mode. In such a way, a multicolor containing a full color copy and a black toner can be obtained easily by one set.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a copying machine capable of producing monochrome copies, multicolor copies, and full color copies.

(Prior art) Digital color copying machines that use multiple photoreceptor drums and perform exposure using laser beams have been proposed as both full-color and monochrome copying machines, but because of the digital method, the smoothness of text, etc. is particularly poor. It is problematic for use in acid offices because it is prone to chipping and is expensive.

Furthermore, even in the analog system, a full-color/mono-color copying machine has been proposed, which is configured to add a developing device for monocolors such as black and white around a single photoreceptor drum, and is configured to make monocolor copies. The disadvantage is that the speed is slow because exposure and transfer are repeated to obtain copies.

Furthermore, as an example of obtaining a multi-color copy by multiple exposures, there is an apparatus shown in Japanese Patent Application Laid-Open No. 61-203474, but in this case, a plurality of developing devices are installed around one photosensitive drum. This method has the disadvantage that it is only possible to differentiate colors in the direction perpendicular to the paper traveling direction and across the entire width of the paper, and cannot be applied, for example, when it is desired to emphasize only the central part of the document by changing the color.

(Purpose) With the spread of personal computers, word processors, etc., the number of color documents printed on color printers has increased in offices, and the demand for office-use full-color copiers that can easily make high-speed color copies has increased, and several full-color copiers are already available. has been done. On the other hand, even among black and white copying machines, multicolor copying machines have been provided in which a color toner developing device outside the focal range is added for identification and partial emphasis of copies.

However, there are currently no copiers available that have both full color and multicolor functions, including black and white, and if you need both types of copying, you must install both a full color and multicolor machine, which is costly. There is a problem with the upper level.

Therefore, the purpose of the present invention is to provide a high-speed, all-purpose copying machine for office use that can easily make full-color copies and multi-color copies including black toner.

(Structure) The present invention provides a copying apparatus that is equipped with a plurality of photoreceptor belts and can obtain a full-color copy by performing simultaneous slit exposure by splitting the optical path. Mono-color copying and multi-color copying can be performed by switching between different optical paths to create images on each photoreceptor belt depending on the optical path length, specifying the area of the electrostatic latent image as necessary, and controlling the operation of the desired developing device. , a black and white copying machine that produces full color copies.

The configuration of the present invention will be described below based on one embodiment. FIG. 1 is an overall configuration diagram of an embodiment of a black-and-white and color copying apparatus according to the present invention.

The configuration and operation of this device will be explained with reference to FIG.

The twelfth mirror 201 and the fourteenth mirror 203 are half mirrors that can reflect and transmit light at a certain rate, and are fixed between the ninth mirror 101 and the tenth mirror 102. 13th mirror 202, 15th mirror 20
4 are the third photoreceptor belt 53'', the second photoreceptor belt 53', and the eighth mirror 1f and the seventh mirror 17 are located between the exposure projection position 1f23.22 and the seventh mirror 17, respectively. A position where the optical path from the mirror 17 is not blocked (shown by a solid line) and a position where the light flux from the 12th mirror 201 and the 14th mirror 203 is reflected to the exposure projection position i!23.22 if(
This is a total reflection mirror that can be switched between (shown with a broken line). These mirrors are installed so that the optical path length is the same as in full color mode.

Next, the operation and effect of the above configuration will be explained. First, when the full color copy mode is selected, the ninth mirror 101 and the eleventh mirror 103 are moved to the solid line position and held there by a driving method such as a motor or a solenoid (not shown).

The original on the original table 1 is illuminated by an illumination lamp 3, and the reflected light passes through the first mirror 11, the second mirror 12, the third mirror 13, the fourth mirror 14, the lens 2, and the fifth mirror 15. 6 mirror 16. The sixth mirror 16 is a half mirror, and has three colors: blue, green, and red.
It has spectral characteristics such that it reflects one color of light and transmits the other two colors. The reflected light from the sixth mirror 16 forms an image on the projection position 21 of the first photoreceptor belt 53.

The light beams of the other two colors that have passed through the mirror tube 6 are divided into slits by the seventh mirror 17.

The light in the slit area of the seventh mirror 17 is
Either one of the spectral reflection characteristics or a combination of both allows only one specific color of light to be transmitted to the second photoreceptor belt 53'.
The image is formed at a projection position ff122.

The light outside the area of the seventh mirror 17 is transmitted to the eighth mirror 1.
The remaining one color of light is imaged at the projection position 23 of the third photoreceptor belt 53'' by one or a combination of the spectral reflection characteristics of the filter 8 and the spectral transmission characteristics of the filter 32.

In the following explanation of the color copy image forming process, a blue light image is projected at the first photoreceptor belt 530 at the projection position 21, a green light image is projected at the second photoreceptor belt 530 at the projection position 1!22, and a green light image is projected at the third
The explanation will be given assuming that a red light image is formed at the projection position 23 of the photoreceptor belt.

The first to third photoreceptor belts 53, 53', 53'' are rotated by clockwise rotation of the respective driving rollers 51, 51', 51''.
It is driven in the direction of the arrow in the figure.

First, each photoreceptor belt has its own quenching device! 4L41'
, 41'', and then uniformly charged by each main charger 43, 43', 43''. Then, at projection positions 121, 22, and 23, the original images separated into blue, green, and red are simultaneously exposed.

As a result, an electrostatic latent image is formed on each photoreceptor belt surface, but the charges on the photoreceptor belt surface outside the area of the original size or the size of the transfer paper 70 are removed by each eraser 42.
The charges are removed by 42' and 42'', respectively.

Next, in the developing step, since the first photoreceptor belt 53 has been exposed to blue light, it is visualized with yellow toner, which is a complementary color to blue, by six developing devices.

Since the second photoreceptor belt 53' has been exposed to green light, the developing device W161' uses magenta toner, which is also a complementary color, and since the third photoreceptor belt 53'' has been exposed to red, the developing device W161'' uses cyan toner. Be visualized.

These photoreceptor surfaces on which toner images have been formed are each subjected to charge removal by pre-transfer charge eliminators 64, 64', 64'', and advance to respective transfer positions 21', 22', 23'. The timing at which the toner images arrive is such that each toner image is transferred to the same position on the transfer paper.

Transfer paper 70 is fed by paper feed roller 71 and registration rollers 72 and 73.
position, and then move the registration rollers 72.7 at a timing that matches the toner image position on the photoreceptor belt.
The transfer paper is fed in the direction of the transfer paper conveyance belt 54 by rotation No. 3. The transfer paper conveyance belt 54 is driven in the direction of the arrow in the figure by counterclockwise rotation of a drive roller 55.

The transfer paper sent out by the registration rollers 72 and 73 is sandwiched between the presser roller 74 and the transfer paper conveyance belt 54, and then transferred to the third
The cyan color transfer position 23' of the photoreceptor belt 53'' is reached.

At the cyan color transfer position 23', the cyan toner image is transferred to the transfer paper.

Then, at the magenta color transfer position 22' which is further conveyed, the magenta toner image on the second photoreceptor belt 53' is transferred again to the yellow color transfer position! At step 21', the yellow toner image on the first photoreceptor belt 53 is transferred onto the transfer paper.

As a result, on the transfer paper that has passed the transfer position 21',
An overlapping image is formed using a combination of yellow, magenta, and cyan color toners.

In order to make these three-color toner images coincide on the transfer paper, differences α and β in the circumferential length from the exposure position to the transfer position of each of the first to third photoconductors, and distances α′ and β′ between the respective transfer positions are determined. It is necessary to meet the following conditions.

That is, if the configuration is such that α=α′ β=β′, an image in which the toner images of each color are aligned will be obtained.

The transfer paper that has passed the transfer position ra21' is moved by the drive roller 55.
The toner image is separated from the conveyor belt 54 at the section, the toner image is fixed by a fixing device 75, and the toner image is ejected onto a paper ejection tray 76 to obtain a color copy.

On the other hand, each photoreceptor belt is cleaned of the toner in the rows after transfer by each cleaning device 62, 62', 62'', and further cleaned by each quenching device 41, 41', 4
1" is quenched.

Further, the transfer paper conveyance belt 54 is equipped with a transfer belt static eliminator 0!6.
After being neutralized in step 5, the transfer belt is cleaned by a transfer belt cleaning device 66.

Next, the monochrome copy mode will be explained. Monochrome copy mode is when a monochrome copy is obtained by scanning the original once. In the apparatus of this embodiment, full-color developing units 61, 61', 61'' and an additional developing unit 104 are set, and four colors can be selected and used without replacing the developing units. Now, we will explain the case where a monochrome copy mode with cyan, which can generally be recognized as blue, is selected.First, when the mode is selected, the ninth mirror 101 and the thirteenth mirror 202
moves to the dashed line position and is securely positioned and held. At this time, the reflected light from the document surface is reflected by the fifth mirror 15, then reflected by the ninth mirror 10g, the twelfth mirror 201, and the thirteenth mirror 202, and is focused at the same position 23 as the projection position by the eighth mirror. Image.

Next, the electrostatic latent image on the photoreceptor belt 53'' is transferred to the developing device 6.
1" to obtain a blue (cyan) copy. At this time, the first and second photoreceptor belts are prevented from forming an image by turning off their charges or the like.

Copies in magenta that can be recognized as red, copies in yellow,
In the case of a black and white copy (assuming that black toner is contained in the developing device iris 04), the 12th mirror 201 and the 14th mirror 203 are half mirrors, so the same operation as in the case of cyan is performed. I can do things.

Next, the multicolor mode will be explained.

The multicolor mode is a mode in which a specified zone on a document is developed in a specified color by scanning the document twice to obtain a copy.

A case will be described in which a part 301 of a monochrome original as shown in FIG. 2(a) is highlighted in blue (cyan), a part 302 is highlighted in red (magenta), and the other parts are copied in black.

First, place the original on a digitizer (not shown), specify the zone you want to emphasize, select the desired color (black, blue, and red in this example), and specify multicolor mode.

In this case, the ninth mirror 101, the eleventh mirror 103, the thirteenth mirror 202, and the fifteenth mirror 204 move to the dashed line positions and are reliably positioned and held.

At this time, the reflected light from the document surface is reflected by the ninth mirror 101, and then passes through each mirror and is exposed and projected onto the first, second, and third photoreceptors. Prior to exposure, each photoreceptor has eraser parts (42, 42', 42'') that erase charges from unnecessary parts corresponding to the zones specified by the digitizer, and the electrostatic latent image only in the specified zones is exposed to light. The electrostatic latent images formed on each phosphor are then developed by cyan, magenta, and black developing devices, respectively, as shown in FIG. 2(b).
A three-color multicolor copy including black can be obtained as shown in the image below.

The developing device 104 and the developing device 61 are configured such that when one developing device is used to develop an image, the other developing device may produce [f-images or stains].
Considerations have been taken to remove the unit or the developing roller from the photoreceptor surface so as not to have an adverse effect on the toner, and to perform magnetic and electrical control to prevent the toner from coming into contact with the photoreceptor surface.

In this embodiment, in addition to the yellow, magenta, and cyan developing units, an additional developing unit 104 is provided in the first photoconductor section, but if space permits, the second and third photoconductor sections Additional developing devices may be installed, such as one for green color and one for sepia color.Also, if it is an office copier, the proportion of copies made using black toner is likely to be high, so an additional developing device may be installed on each belt section. It is also possible to extend the life of the photoreceptor, whose life is determined by the number of times of image formation, by providing a black developing device and switching the image formation location during black and white mode.

Furthermore, regarding switching of process conditions in each mode, in the apparatus of the present invention, the image forming position is the same whether in color mode or monochrome mode, so the registration between the developed image on the photoreceptor and the paper being conveyed is difficult. The timing control is exactly the same, but other process conditions, such as the amount of charge,
It is a matter of course that consideration is given so that the exposure amount, transfer conditions, fixing conditions, etc. can be automatically switched as necessary at the same time as the mode is switched.

Furthermore, in black-and-white mode (mono-color mode), the entire luminous flux from the fifth mirror 15 is projected onto the photoreceptor belt, so there is more leeway in terms of photoreceptor sensitivity that determines the copying speed, power consumption, etc. Copying speed can be increased compared to full color mode.

(Effects) With a simple configuration, it is possible to provide a versatile copying machine capable of making full-color copies, mono-color copies, and multi-color copies by scanning an original document twice.

When switching between full color, monocolor, and multicolor modes, the optical path splitting mirror system, which has a major impact on full color image quality (misalignment of Y, M, and C colors), is not affected at all, so high-quality full color copies are maintained. In addition to this, continuous transfer is possible in multi-color printing as well as in full-color printing, and copies without registration errors can be obtained at high speed.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a black-and-white and color copying machine which is an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a multicolor copying machine. 1... Original table, 2... Lens: 1x position, 2
′... Lens: Enlargement position, 2''... Lens: Reduced position, 3... Illumination lamp, 21, 22. 23...
・Projection position, 21', 22', 23'...transfer position,
31゜32...filter, 41.41', 41"・
...Quenching device, 42.42', 42"...
Eraser, 43.43', 43"...Main charger, 61.61', 61"...Phenomenon device, 62
．． 62'. 62"...Cleaning device, 63.63', 63"
...Transfer device, 70...Transfer paper, 301,302.
...Color emphasis section.

Claims (1)

[Scope of Claims] 1) In a full-color copying machine that performs simultaneous slit exposure by splitting optical paths using a plurality of photoreceptor belts, a color separation optical path for making a full-color copy is independent of the color separation optical path, and the color separation optical path is independent of the color separation optical path, and An optical path that creates an image on each photoreceptor belt with an optical path length equal to the color separation optical path, and an optical system that can switch these optical paths are provided, and the area of the electrostatic latent image can be specified according to the required mode to create the desired image. A black and white color copying machine that is equipped with a control device that controls the operation of the developing device and is capable of monochrome copying, multicolor copying, and full color copying. 2) A patent claim that uses a mirror that is taken in and out of the optical path before color separation as an optical system that switches the optical path, and uses a half mirror that divides the light directed toward each photoreceptor into an optical path independent of the color separation optical path. A monochrome and color duplex copying machine as described in Scope 1.