JPH0451669A - Digital copying device - Google Patents

Abstract

PURPOSE:To facilitate discrimination in case that the color of a toner is different by deciding the area of a color picture and marking this area by a dot, etc., when the color of picture data obtained by separation by a reading means and the color of a picture capable of being formed by an image forming means are different. CONSTITUTION:When the discriminated color and the color of the toner are different from each other, namely, for instance, when there is a red part in an original, and the data of red is separated, if the toner of blue is charged accidentally in a color developing unit 220, since the color codes of the discrimination and development do not coincide, the area of the discriminated data of the red is decided, and the picture is formed with the toner of the blue by overlaying the dot on the data. Accordingly, it can be discriminated that the picture of the original formed in the blue is not blue but of another color from a copy based on the formed dot. Thus, when the color of the original does not coincide with the formed color, marking by the dot, etc., is executed, and the discrimination can be facilitated.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention identifies a specific color based on data read from a document, and sequentially writes recording signals of two or more colors obtained by the identification onto a photoreceptor. The present invention relates to an electrophotographic digital copying device having a color identification function for producing hard copies (duplicates) of two or more colors in one transfer.

[Conventional technology]

Conventionally, electrophotographic digital copying involves scanning a light beam from a light source on a scanning medium such as a photoreceptor to form an electrostatic latent image, and developing this electrostatic latent image with toner to make it visible. This digital copying device is widely used not only as a normal copying machine but also as a facsimile machine, a computer output device, etc. In particular, with the spread of color display, color recording is becoming more popular. With demand and the spread of color copying machines, two-color or multi-color recording has come to be performed.

Here, as an example of an apparatus for obtaining a two-color hard copy, in the image forming apparatus described in Japanese Patent Application Laid-open No. 1-228269, first, in the first copying process, the original is scanned and read; Data of a specific color is obtained by color identification, and after predetermined image processing is performed, it is binarized and written on a photoreceptor, developed, transferred, and fixed, and the copy is guided to the re-feed tray. In the second copying process, the original is scanned and read again, data of a different color than the first time is obtained by color identification, and after predetermined image processing is performed, it is binarized, written on a photoreceptor, and developed. The transfer paper on which the first image has been formed is sent out from the re-feeding tray, transferred, and fixed to obtain a two-color copy.

However, the above publication does not mention what to do when there is a discrepancy between the identified image data and the colors that can be formed.

Furthermore, Japanese Patent Laid-Open No. 56-87058 discloses an electrophotographic device that simultaneously forms two colors in one rotation of a photoreceptor drum; There is no mention of what to do when there is a discrepancy between the identified image data and the colors that can be formed.

[Problem to be solved by the invention]

Conventionally, when using a copying machine that has the function of identifying and separating specific colors from a two-color or three or more-color original and making two-color copies of the identified color and black, there is a conventional If the machine is used as a monochrome copying machine and the toner color of the second color developing unit is set to a different color, if copying is performed as is, the image data of the identified color will be copied in a different color. A problem arises in that it is impossible to tell what color the original was from the copies made in this way, even though the copying machine has a color identification function.

The present invention has been made in view of the above circumstances, and in order to prevent the above-mentioned situation, when the color to be identified and the color of the set toner are different.

It is an object of the present invention to provide a digital copying apparatus having a function of making markings such as halftone dots on parts formed in different colors so that the difference can be easily identified.

Another object of the present invention is to provide a digital copying device that can make copies without causing problems even when the color to be identified is different from the color of toner set in the developing unit. do.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a reading means for receiving a light image from an object to be copied and separating image data of a predetermined color to obtain a plurality of image data; In a digital copying apparatus comprising a writing and image forming means for writing and developing with a plurality of color developers to form a multicolor image, the color of the image data separated by the reading means and the image formation When the color of the image that can be formed by the means is different, the area of the color image is determined, and the area is marked with halftone dots or the like.

More specifically, in the present invention, the digital copying apparatus includes means for generating a color code for identification by a reading device, and generating a color code for toner set in a developing unit containing color toner. A means is provided to compare and determine the color code to be read and the toner color code, and when a mismatch between the codes is detected, the area of the color image is determined from the color image data, and halftone dots are placed in the determined area. Do an overlay.

[For production]

In the digital copying apparatus of the present invention, when the identified color and the toner color are different, the data for that color is developed in a color different from the identified color, but as described above, the data includes halftone dots, etc. Since it is formed by overlaying the original, it is easy to see that the original color is a different color when looking at the copy.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

First, an outline of a copying apparatus for forming an identification monochrome image according to the present invention will be explained with reference to the block diagram shown in FIG.

In Figure 1, the reading system scans the document in a direction perpendicular to the slit while illuminating the document in a slit shape with a light source, and uses a lens, reflector, etc. to produce a reflected light image in a direction parallel to the slit for illumination. An image is formed on two line-shaped imaging sections in which a large number of photoelectric conversion elements are arranged. At this time, an optical image that does not include image data of a predetermined color is formed in one imaging section through a transmission type filter of the color to be identified, and an illumination light source and a lens are formed in the other imaging section. , an optical image of the entire spectrum of light determined by a mirror or the like is formed.

Here, in a device that can change the color to be identified, a color encoder is provided that allows the controller 1 to change the color to be identified in accordance with the changing operation.

In addition, in devices where the identification color cannot be changed, the color code corresponding to the unique color is stored in memory, and the controller
enables the recognition of colors.

Next, a color separation circuit performs color separation from the output signals of these two imaging means, converting all colors including the color to be separated into brightness signals, and a monochrome image signal and a filter color image signal. Separate into two parts. Then, the image data is further A/D converted, predetermined image processing is performed as necessary, and each image data is written as an electrical signal into a buffer memory for timing adjustment with a writing system, which will be described later.

On the other hand, the controller 2 reads the color of the toner contained in the color developing unit from an encoder attached to the unit, and sends it to the controller 1. The controller 1 determines whether the colors match or do not match based on the color code identified by the reading system and the toner color coat of the color developing unit sent from the controller 2.

Here, if it is determined that there is a mismatch, a circuit that determines the area of the color image from the data in the buffer memory that holds the color image data for time adjustment, and a halftone dot pattern based on the area determination result. Start the overlay halftone data generator and gate. Then, the area is determined for the data in the buffer memory, and when image data is sent for writing, overlay is performed by logically ORing the area data determined to be the output of the halftone dot generator and the image data.

In addition, since this device uses a method in which color image writing is performed downstream, it has a buffer memory to compensate for the writing time, and the configuration is such that this memory and time delay can be tolerated. Since the above-mentioned area determination and halftone dot overlay are performed by utilizing the above-mentioned method, the functions of the present application can be realized while suppressing an increase in the number of parts and cost.

Now, the writing system that writes image data onto the photoreceptor with light converts image data sent by a command signal from the controller 1 into an optical signal at a predetermined timing, and writes the converted image data onto the photoreceptor.

The controller 2 that controls the image forming section is the controller 1
By exchanging data with the controller 1, the writing system sends a timing signal for starting writing to the controller 1, and controls the image forming section that forms an image using electrophotography to match the timing, and identifies the A monochrome hard copy corresponding to the color data (
make a copy).

These reading system, writing system, and image forming section are controlled with timing adjusted by a controller 1 and a controller 2, which are connected through a mutual communication path.
Each function is executed while sending and receiving data necessary for each operation under the control of the controller 1.2.

Hereinafter, each function will be explained based on the block diagram of FIG. 1.

Here, FIG. 2 shows an imaging lens placed between the document illumination and photoelectric conversion in FIG. The devices CCDI and CCD2 are shown.

As shown in FIG. 2, the reflected light from the original is focused by a lens and is incident on two prisms each having a half mirror on the boundary surface. The light split into transmitted light and reflected light by the half mirror is totally reflected by each prism and then sent to CCD1 and CCD.
Image is formed on CD2.

On the CCD 2 side, a filter of the color to be identified from the original is inserted. For example, when identifying red from a document, a red absorption filter is inserted. The advantage of using two prisms here is that CCD 1 and C0D2 can be placed on the same plane. That is, if the CCD 1 and the CCD 2 are placed on the same plane, assembly, adjustment, etc. will be easier.

The reflective surfaces of the lens, prism 1, and half mirror have characteristics that do not absorb light in a specific spectrum in the visibility band from the light reflected from the original, and an image of the original in white light is formed on the CCD 1. Image. In other words, information about the image of the original is received as information about the brightness of the reflected light. When a red filter is inserted in the CCD2, light other than red is absorbed, so images of colors other than red and black on the original are black, light reflected from the red image is transmitted, and light reflected from white is colored red. Only the components pass through. Therefore, as image data received by the CCD 2, the level of reflection from the white part of the original and the reflection from the red part of the original are the same, resulting in data in which white and red cannot be distinguished.

When receiving reflections from areas of other colors, the amount of light decreases due to absorption by the filter, and is interpreted as dark data. In other words, the image data is obtained by removing the red image data from the image data of the CCD 1.

Furthermore, by inserting a filter of another color, you can similarly obtain image data excluding the image data of that color.

The purpose of inserting the filter as shown in Figure 2 is to identify the changed color when changing the color of the toner stored in the second color developing device, which will be described later. This is because when you want to match the colors, you can easily do this by replacing the filter. In this case, multiple filters are provided so that they can be replaced using a stepping motor, and the controller 1 obtains a color code to be identified from the rotation angle data of the motor to match the color of the toner in the color developing unit. , used as data to determine inconsistency.

Also, if you don't need to replace the filter alone.

By giving prism 2 a filter function, giving a filter effect to the light transmitted through the half mirror, and
A method such as gluing a filter to 0D2 can be used.

Next, FIG. 3 shows an embodiment of an imaging device section having another color separation function in place of the one shown in FIG. This shows the arrangement of the light receiving unit and the functional blocks that operate the signals obtained by receiving the light. These are I with a window at the top for receiving light.
It is housed in a C package.

Here, the light receiving section 2 has a filter formed on the surface of the C-chip and has the function of the CCD 2 shown in FIG. 2, and the light receiving section 1 has the same function of <CCD1.

Further, the lines of the light receiving sections 1 and 2 are arranged so as to line up on the image formation plane of the imaging lens in a direction perpendicular to the scanning direction of the reading system while illuminating the document with slit exposure. Since the image formed on the two-line CCD moves according to scanning for reading the original, the light receiving section 1 is arranged so as to be on the upstream side in the direction of movement on the image forming plane.

The image formed on the light receiving sections arranged in the direction in which the document is scanned moves in accordance with the speed at which the document is scanned. The distance between the lines is equivalent to one pixel, and the scanning speed is determined so that the distance traveled is equivalent to one pixel in the time it takes to scan one pixel, so the image detected by the light receiving unit 1 located on the upstream side is , and is inspected by the light receiving section 2 with a delay corresponding to one pixel in the sub-scanning direction.

To identify the color of a document, image data at the same position on the document is compared, so an analog memory is provided on the upstream side of the light receiving section 1 in order to compensate for a delay of one pixel.

Each light-receiving section converts light into an electrical signal, and more specifically, it changes the flowing current depending on the intensity of the light, integrates the change in current, and converts it into an amount of charge.

The photo storage gate controls the start and stop of integration, and the charge accumulated by integration for a predetermined period of time is transferred to the shift register by the shift gate. The charge transferred to the shift register is sequentially moved in the direction of the arrow in the figure by a shift lock (not shown in the figure) that transfers in the line direction of the shift register, and the amount of charge is converted into voltage at the output section. Outputs image data as analog voltage data.

Note that the data of the light receiving section 1 is the same as that of the light receiving section 2 except that it is delayed by one line in the analog memory. Also, output 1. Outputs 2 are respectively output from CCD1. Corresponds to the output of CCD2.

The feature of this color identification method is that compared to color identification using a 3-line CCD equipped with R, G, and B filters, only a specific color can be identified, but because it uses 2 lines, various gates other than the light receiving section and shift Since peripheral circuit elements such as registers can be placed on both sides of the light receiving section, two light receiving sections can be placed adjacent to each other. Since the two light receiving sections are adjacent to each other, only one buffer line is required to adjust the time difference between the lines. Furthermore, since IC manufacturing technology can be applied as is, it is easy to increase the degree of parallelism and alignment between the two lines, making it easy to adjust the reading system. However, since it has a built-in filter, it is no longer possible to change the color it identifies by simply replacing the filter.

Note that even if the controller 1 does not have a function to change the color of the filter, the controller 1 is configured to hold a color code unique to the reading system so that it can determine whether the color of the toner in the color development unit matches or does not match. There is.

Next, FIG. 4 is a more detailed block diagram of the reading system shown in FIG. 1 after the photoelectric conversion section.

Here, CCD1 and CCD2 in FIG. 4 correspond to CCD1 and CCD2 in FIGS. 2 and 3, and respectively output an image signal not passed through a filter and an image signal excluding an image signal of the color of the filter. As an example, the signal of CCD1 is represented by W (white), and the signal of CCD2 is represented by W (white)-R (red).

In FIG. 4, W is input to an amplifier A1 whose amplification degree can be set by an external signal AGC1. This AGCI is set to A1 from the memory in synchronization with the image data by a start command from the controller 1 shown in FIG.
Variations in sensitivity between CD light receiving elements are corrected.

In other words, so-called shading correction is performed.

Here, A1 is an inverting amplifier, and its output is assumed to be B. In addition, W and W-R are input to input terminals with different polarities in A2, W-R is subtracted from W, and at the same time, similar to A1, image data R is corrected by AGC2 and has the same color as the filter color. is output. In addition, output B (black) from A1
is converted into 6-bit digital data by an A/D converter.

Image data R is subjected to 1-bit A/D conversion, that is, binarized. This binarization level is configured to be variable by a signal from the controller, similar to the binarization levels of An and A2. For example, if the paper of the original to be copied is pale pink, there are cases in which the background of the original is desired to be copied in red and in cases in which it is desired to be copied in white. In such a case, each case can be handled by changing the level of binarization using a selection signal from the operation section.

6 obtained by A/D converting B using this binary signal of R.
The gate before inputting the bit data to the γ converter is R
The gate is closed when a binary signal exists, and the gate is opened when there is no signal.

This gate is pulled down on the output side so that the output data is blank data when it is closed. Therefore, when there is a signal obtained by binarizing R, blanks are inserted as B data, and when there is no signal, B data is passed through as is.

In other words, since the B data is switched using the binarized R data, even if there is a problem with the alignment or parallelism of the CCDI and CCD2, the image at a certain position will not be red and black at the same time. The configuration is such that it essentially does not occur.

The 6-bit B-R data input to the γ conversion section is 8
It is converted into 8-bit data using a table configured to select any 64 states that can be expressed in 6 bits from 256 states that can be expressed in bits, and written to the buffer memory.

This conversion unit corrects the input/output characteristics of the reading system, corrects the relationship between the writing light amount of the image forming unit using electrophotography and the image density of the copy, and performs binarization by rewriting the data in the table to be converted by the controller 1. ,negative·
You can perform positive inversion, etc.

Next, FIG. 5 shows a case where both the first write data and the second write data are multivalued. This is almost the same as FIG. 4 except that the second writing is multivalued. This fifth
In the case of the configuration shown in the figure as well, the B data is switched with the binarized R data to obtain black and red multi-valued data. Even when both are multivalued in this way, image data for each of the two colors is obtained by switching, so the two image data do not overlap. Also, in this case, the area is determined using the binarized R data, and halftone dots are overlaid on the multivalued data using the area data.

Next, an outline of the structure of a digital copying apparatus for forming an identification monochrome image according to the present invention will be explained.

FIG. 6 is a sectional view showing the outline of the structure of the digital copying apparatus.

This apparatus is divided into an upper document scanning/reading section 100 and a printer section 200 that forms images using an electrophotographic method. The document scanning/reading section 100 includes a contact glass 101 on which a document to be copied is placed, a document pressure plate 102 that presses the placed document, a light source 103 that illuminates the document, and a reflector 109 that focuses the light from the light source onto a part of the document that is to be read. , mirrors 104, 105, and 106 that guide reflected light from the original to the imaging device 108 to form an image, a lens 107, and a drive mechanism including a motor (not shown) for scanning the original.

Imaging device! 108 is a CCD shown in FIGS. 1 to 5;
1. Has functions corresponding to C0D2.

FIG. 6 shows an example using the two-line CCD shown in FIG. 3, but of course the embodiment using the prism shown in FIG. 2 can also be applied.

In the apparatus having the configuration shown in FIG. 6, when a document is set on the contact glass 101 and copying is started by pressing the print button on the operation panel, the lamp 103 that illuminates the document lights up and the motor that scans the document is driven. . The reflected light from the original forms an image on the imaging device 1o8, and image data of the first-order original is output line by line in response to changes in the scanning position of the original.

The output data is subjected to the processing described above and written to a buffer memory for timing matching with the writing section described later.

The printer section is the writing section 2 surrounded by a chain line in the figure.
50, black developing unit 210, red developing unit 220,
Transfer/transport unit 230, cleaning unit 240
, a photoconductor 201, a static elimination charger 202 that eliminates static electricity before cleaning the photoconductor, a main charger 205 that charges the photoconductor, a fixing unit 260, a belt cleaning unit 270 that cleans the transfer/conveyance unit 230, and a feeder that supplies transfer paper. It is composed of a paper unit 290, a registration unit 280 that aligns the transfer paper and the image on the photoreceptor, and the like.

The writing section 250 is equipped with a motor that integrates an eight-sided polygon mirror 251, and inputs a laser beam modulated by a black image signal into the polygon mirror 251 rotated by the motor, and converts the reflected beam from the polygon mirror 251 into one. A light beam 252 formed through optical components such as an Fθ lens, a reflector, and a dustproof glass for scanning the photoreceptor 201 at a constant speed and a laser beam modulated by a red image signal are rotated by the motor. The light beam 253 that enters the opposite surface of the polygon mirror 251 and is formed via a similar optical component that scans the photoreceptor 201 at a constant speed with the reflected beam from the polygon mirror 251 generates two-color image data. is written on the photoreceptor 201.

Both beams 252 and 253 are connected to one polygon mirror 25
Since both sides of the photoreceptor are used for scanning, the scanning direction of the beam on the photoreceptor is reversed. FIG. 7 shows the polygon mirror 251 viewed from above and the beams 252 and 253 with the reflecting mirror omitted.
FIG. The arrow of the polygon mirror 251 indicates the direction of rotation, and the direction of rotation of the photoreceptor 2 at that time is
The scanning direction of each beam at 01 is indicated by an arrow.

Here, by setting the positional relationship of the semiconductor laser LDI that outputs the beam 252 corresponding to black and the semiconductor laser LD2 that outputs the beam 253 corresponding to red to a predetermined position with respect to the polygon mirror 251, the positional relationship between the beams is determined. is determined, the sensor D for detecting the position of the laser beam and obtaining the timing to start modulation based on the data for each line is installed only on the abusive beam 252, and the sensor D is installed only on the line of the red beam 253. The timing to start each modulation is generated from the signal from the same sensor.

Also, the beam 252 of the hot saw writes at position A on the photoreceptor drum, and the red beam 253 writes at position B, so the red beam 253 writes by the number of lines corresponding to the distance between AB. By performing writing with a delay, an image with no deviation between black and red image data can be obtained. For this reason, the red data to be written downstream is read and subjected to predetermined processing, and then written to the buffer memory of the number of lines corresponding to this shift to compensate for the time shift.

Next, a series of processes for forming an image using an electrophotographic method in the copying apparatus shown in FIG. 6 will be described.

First, the main charger 205 uniformly charges the photoreceptor 201 rotating in the direction of the arrow in the figure, and a light beam 252 modulated with black image data applies A to the charged photoreceptor 201.
Write with points. The electrostatic latent image formed by this writing is developed by a thermal development unit to form a black developed image on the photoreceptor.

Furthermore, writing is performed at point B on the photoreceptor on which a black image has been formed using a light beam 253 modulated with red image data.

Next, while not disturbing the black developed image, the red developing unit 220 develops only the latent image portion formed by the red image data, thereby forming a two-color developed image on the photoreceptor. . In parallel with this, transfer paper is sent out from the paper feed section 290,
The sheet is sent to the transfer/conveyance unit 230 so that the position of the leading edge of the formed two-color developed image and the leading edge of the transfer paper are aligned by the registration unit 280. The transfer paper sent out in this manner is carried by the belt of the conveyance unit 230, comes into contact with the two-color developing image on the photoreceptor 201, and is corona charged by a transfer charger installed on the back side of the belt. The upper two-color developed image is transferred to transfer paper. After the transfer, the transfer paper is further conveyed, fixed by the fixing unit 260, and discharged outside the machine. In addition, the photoreceptor 2 after transfer
01 is neutralized by the static eliminating charger 202, and then cleaned by the cleaning unit 240, and is ready for image formation in the next cycle. Further, the belt of the transfer/conveyance unit 230 that conveyed the transfer paper to the fixing unit is cleaned by a belt cleaning unit 270, and thereby the belt is rubbed once to prevent stains on the back side of the next transfer paper.

Now, in the copying machine shown in FIG. 6, in the series of operations described above, if there is a red part in the document placed on the contact glass 101 of the copying machine, that part is automatically separated. 2 at exactly the same copy speed as for black-only originals.
Create a color copy. Of course, if the original is only black, it will make a black copy just like a normal copying machine. Therefore, the person who scans this copying device does not have to worry about whether there is a red part in the document; the process is automatically done, so it is not bothersome.

Furthermore, if there is a red part in the document and blue toner happens to be in the color development unit 220 when the red data is separated, the identification and development color codes will not match. The area of the data is determined, halftone dots are overlaid on the data, and an image is formed using blue toner. Therefore, from the formed halftone dots, it can be determined from the copy that the original image formed in blue is not blue but in another color.

Of course, the color recognition function allows the machine to not only make copies in color, but also to have functions similar to those of conventional monochrome copying machines or copying machines that have a partial color change function.

Next, FIG. 8 is a block diagram mainly showing the control system of the printer section of the controller 2, which controls everything other than image reading, image data processing, and writing sections.

This control system includes the printer motor, solenoid, clutch, various detection switches, input/output, sorter, AD
a microcomputer 1 that controls peripheral devices such as F;
The microcomputer 2 includes a microcomputer 2 that controls a display section and an operation section, and a microcomputer 3 that controls the drive for scanning a document, the document illumination lamp, and the temperature of a fixing heater. Each of them is connected by a communication path with the microcomputer 1 as the master. As shown in the figure, a path for exchanging signals that cannot be completed in time by this path alone is also provided between the microcomputers 1 and 3 and the controller 1 that controls image reading and writing. . Note that the control system is the same as that of a conventional copying machine except that it has an interface with the controller 1 that handles image data, so a description thereof will be omitted.

Now, in the above embodiment, the color of the first developing device is black, the color of the second developing device is red, and the function for identifying the color of the original is made to match the respective colors. , in the case of a mismatch, halftone dots are added to indicate the mismatch in color of the original to be copied, but the operation panel is equipped with a function to select a mode other than the one in the example, so that identification can be made according to the user's selection. You can also change the color and the developing color to achieve a special effect. That is, for the convenience of user selection, a display of a color to be distinguished from the toner color may be individually provided on the operation section.

Furthermore, since the second color image is written downstream of the photoreceptor compared to the first color, there is a time delay and a memory is required to compensate for the delay. Images are written in binarized form, reducing memory capacity and reducing costs.

In the above description, the present invention was applied to a copying apparatus. However, the present invention sequentially writes recording signals of two colors onto a photoconductor to form a two-color toner image on the photoconductor. It can also be applied as an electrophotographic printer that obtains two-color hard copies in one transfer, and especially when multivalued data containing color signals is sent from the print data sender, the sent color data When the color that can be formed is different from the color that can be formed, it can be applied as a printer that prints in the color that can be formed and also performs marking.

〔Effect of the invention〕

As explained above, a conventional copying device with a color identification function is characterized in that even if the user copies the original without paying any attention to the color of the original, the original containing a predetermined color can be copied as is. Therefore, even if the color identified by the device does not match the color of the toner in the developing unit that forms the image, the copy will be made as is, and as far as the copy is concerned, the color of the original is the same as the color that was formed. There has been a problem in that it is not possible to determine whether the color matches or does not match, but in the copying apparatus according to the present invention, if the color of the document does not match the color formed, the marking by halftone dots etc. This allows for easy identification.

Although it is possible to prevent copying if the original color does not match the formed color, a feature of copying machines with a color identification function is that the user does not have to pay attention to the original color. Therefore, in such a case, if an original containing an image in such a color is mixed in with many other documents set in the ADF, copying will be interrupted when it comes time to copy that original. This will cause inconvenience.

In contrast, with the copying apparatus of the present invention, the above-mentioned inconvenience does not occur because it is possible to continue copying and to indicate to the user that there is a difference in color between the original and the copy. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an overview of the configuration of a digital copying apparatus according to the present invention, FIG. 2 is a schematic configuration diagram showing an embodiment of an imaging device equipped with a color separation function, and FIG. FIG. 4 is a block diagram showing an example of a more detailed configuration after the photoelectric conversion section of the reading system of the device shown in FIG. A block diagram showing another example of a more detailed configuration after the photoelectric conversion section of the reading system of the device shown in the figure, FIG. 6 is a cross-sectional view showing the outline of the structure of the digital copying device according to the present invention, and FIG. 7 is a beam FIG. 8 is a block diagram mainly showing the control system of the printer section of the controller 2. FIG. 100... Original scanning/reading unit, 101... Contact glass, 102... Original pressure plate, 103...
... light source, 104, 105, 106 ... mirror 1
07... Lens, 108... Imaging device, 109
... Reflector, 200 ... Printer section, 201
... Photoreceptor, 202 ... Static elimination charger, 20
5... Main charger for charging, 210... Black image unit, 220... Red developing unit, 230
...Transfer/transport unit, 240...Cleaning unit, 250...Writing section, 251...
... Polygon mirror, 252, 253 ... Light beam, 260 ... Fixing unit, 270 ... Belt cleaning unit, 280 ... Registration unit, 290 ... Paper feeding unit.

Claims (1)

[Claims] a reading means for receiving a light image from an object to be copied and separating image data of a predetermined color to obtain a plurality of image data; and a reading means for sequentially writing the plurality of image data on a photoreceptor and developing it with a developer of a plurality of colors. In a digital copying apparatus equipped with a writing and image forming means for forming an image in a plurality of colors, the color of the image data separated and obtained by the reading means is different from the color of the image that can be formed by the image forming means. A digital copying apparatus characterized in that: a digital copying apparatus determines an area of a color image and marks the area with halftone dots or the like;