JPH01232874A - Digital color copying machine - Google Patents

Abstract

PURPOSE:To facilitate the synthesis of a picture by making a prescribed area of a picture data of an original picture into a blank area and inserting the picture data from a picture memory to the blank area. CONSTITUTION:A CCD 14 reads an original picture and its picture data is inputted to a monitor picture memory circuit 201 via a log amplifier 21, an A/D converter 22 and a shading correction circuit 23. A prescribed area of a picture data is formed into a blank area by the monitor picture memory circuit 201 and the picture data from the picture memory is inserted to the blank area. The picture data outputted from the monitor picture memory circuit 201 is fed to a printer head section 31 via a masking processing circuit 24, a monitor picture tone setting circuit 202, an electric variable magnification circuit 210 and a halftone processing circuit 25.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a digital color copying machine that can easily synthesize images.

[Conventional technology and its problems]

Digital color copying machines that convert an original image read by an image sensor into image data, which is a digital signal, and print (form) an image on paper using electrophotography according to this image data have been known for some time. It is.

In digital color copying machines, the most important point in terms of performance is color reproducibility, that is, forming an image with colors as close as possible to the colors of the original image.

A digital color copying machine is equipped with a color adjustment device for performing color adjustment, and the operator operates this color adjustment device to change the color and select a color that is considered to be close to the original, or It is possible to adjust the color to the operator's preference.

Furthermore, digital color copying machines are provided with an image memory that temporarily stores images in order to perform image composition.

However, conventionally, images are stored in image memory as binary data without gradation, so color correction cannot be performed on image data read out from image memory, and color correction cannot be performed when compositing images. It was difficult to make adjustments.

In view of the above-mentioned problems, the present invention is capable of compositing a registered image stored in an image memory means with a predetermined area of a document image, and at the same time, it is possible to perform color correction on the registered image. The aim is to provide a digital color copying machine with a high level of functionality.

[Means to solve the problem]

In order to solve the above-mentioned problems, the present invention provides a means for making a predetermined area of image data of a document image a blank area, and a means for converting an image of a specific area in the document image into image data having gradation. It is characterized by comprising an image memory means for storing, and means for forming an image in the blank area using image data read from the image memory means.

[For production]

The original image is formed on a sheet of paper with a predetermined area set as a blank area.

The image memory means stores an image of a specific area in the original image as image data having gradation. An image is formed in the blank area of the original image on the paper using the image data read from the image memory means, and image synthesis is thereby performed.

At this time, color correction is performed on the image data of the original image or the image data read from the image memory means, as necessary.

The image formation of the original image and the image formation using the image data read from the image memory means are performed by the same printing process or by different printing processes.

〔Example〕

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

FIG. 1 is a front view showing the overall configuration of the copying machine.

This copying machine converts an original image read by an image sensor into image data, which is a digital signal, and prints (forms) an image on paper using an electrophotographic method in accordance with this image data.

In FIG. 1, the scanner 10 includes an exposure lamp 12 that illuminates the original, a rod lens array 13 that collects reflected light from the original, and a contact type CCD that converts the collected light into an electrical signal. It is equipped with a color image sensor 14.

The scanner 10 uses a motor 11 when reading an original image.
, and scans the original on the original platen 16.

The original image irradiated by the exposure lamp 12 is photoelectrically converted by the image sensor 14, and converted by the signal processing section 20 into a print signal of one of yellow, magenta, cyan, or black.

In the print head section 31, the LD drive circuit 33 operates according to the print signal for each color from the signal processing section 20, and the semiconductor laser 34 blinks (see FIG. 3).

A laser beam generated from the semiconductor laser 34 is reflected by the reflecting mirror 37 and exposes the photosensitive drum 41.

The surface of the photosensitive drum 41 is uniformly charged by a charging process 43, and an electrostatic latent image is formed by receiving the above-mentioned exposure.

This electrostatic latent image is developed into yellow, magenta, cyan, or black by one of the developing devices 45a to 45d.

The developed image is transferred by the transfer charger 46 onto a sheet of paper wrapped around the circumferential surface of the transfer drum 51.

After the above steps are repeated for at least one color of yellow, magenta, cyan, or black,
The paper is separated from the transfer drum 51 by the separation claw 47, fixed by the fixing device 48, and then transferred to the paper output tray 49.
The paper is ejected. Between these, the scanner 10
The scanning operation is repeated in synchronization with the rotational operation of the photosensitive drum 41 and the transfer drum 51.

Note that the paper is fed from a paper container 50, and is also fed by a chaffing mechanism 52 provided on the transfer drum 51.
The tip is chucked by the holder to prevent positional deviation during transfer of each color. Further, 42 is an eraser lamp.

FIG. 2 is a diagram showing the arrangement of various keys on the operation panel 70 provided on the top surface of the copying machine.

The operation panel 70 includes a print start key 71 for starting the copying operation, an interrupt key 72 for specifying interrupt copying, a clear/stop key 73, an all reset key 74, a numeric keypad 75, a set key 76, a cancel key 77, and a function key 74. Keys 78 to 81, Jeddah dials 82 and 83 for setting an area of interest or a specific area for image compositing, which will be described later; displaying a document image and displaying various messages to set an area of interest or a specific area; A display section 84 made of liquid crystal or the like is provided.

FIG. 3 is a block diagram showing the configuration of the signal processing section 20. As shown in FIG.

In this figure, a monitor image memory circuit 201 and a monitor image tone setting circuit 202 are characteristic parts of the present invention, and are designed not to operate when a normal copying operation is performed. These will be described later.

R (red) photoelectrically converted by the image sensor 14,
Each image signal of the three colors G (green) and B (blue) is
Each signal is operationally amplified by a log amplifier 21 into a signal having a magnitude corresponding to the image density, and then converted into a digital signal by an AD converter 22. This digital signal is an image signal (image, image data) with gradation, and then
Shading correction is performed by the shading correction circuit 23.

Next, the masking processing circuit 24 processes R, C, and so on.

Image signals (print signals) for printing corresponding to each print color of Y (yellow), M (magenta), C (cyan), and B (black) are developed from the image signals of the three colors of B. It is generated according to the characteristics of the toner in the containers 45a to 45d.

Generally, from the original image signals R, C, B, print signals Y, M,
The conversion formula for converting to C is expressed as follows.

Each of the conversion coefficients a0° to a0 is preset to an appropriate value by theory and experiment so that an image with a color as close as possible to the original image is printed.

Note that the print signal for which color is generated is determined by C.
It is determined sequentially by a control signal from the PU26.

The halftone processing circuit 25 binarizes the print signal from the masking processing circuit 24 using, for example, a dither method.
A binary pseudo-halftone signal is generated.

The clock generator 27 generates a horizontal synchronization signal 5L (Hsync
) and a dot clock signal S2 (CKA), which are supplied to each block of the signal processing section 20.

In the signal processing section 20, as shown in FIG. 6, image data from the image sensor 14 is serially processed in synchronization with the dot crotter signal CKA. Furthermore, each time the horizontal synchronization signal 1 (sync) is generated, the line in the main scanning direction is updated.

In other words, it advances by a unit distance in the sub-scanning direction.

Now, as mentioned above, an appropriate print signal is generated by the masking processing circuit 24, but the difference in color between the original image and the print image is very small for all colors (it is difficult to suppress it. , in a certain limited chromaticity range, it is possible to minimize the difference by performing color adjustment.

In this embodiment, an area (area of interest) in which the operator particularly wants to place emphasis on color reproduction is stored in the image RAM in the original image, and this area is read out multiple times, with each read image having a slightly different color. After making adjustments and reproducing the image in different positions on a sheet of paper in one printing process, the operator selects the image with the most desirable color.
It is configured to copy the entire document image based on the adjustment value (tPi adjustment coefficient). Note that one printing process refers to one copying process for a monochrome image, and refers to a number of copying processes equal to the number of primary colors used for a color image.

Next, this color adjustment selection control (hereinafter referred to as mosaic monitor) will be explained.

The mosaic monitor is realized by a monitor image memory circuit 201 that stores a region of interest, and a monitor image tone setting circuit 202 that performs color adjustment in the printing process.

FIG. 4 is a circuit diagram of the monitor image memory circuit 201.

First, let's talk about how to set the attention area (specific area) in Chapter 10.
This will be explained with reference to the figures.

By placing a document on the document table 16 and performing a preliminary scan with the scanner 10, the display section 8 of the operation panel 70
The original image is roughly displayed in the original area ED of 4, and the main scanning direction (X direction) and sub-scanning direction (Y direction)
The indication lines LPY and LPX are displayed (see Figure 1O).
, these instruction lines LPY.

The intersection of LPX becomes the center of the attention area EA. When the jitter dials 82 and 83 are operated, these indication lines move up and down or left and right, respectively, thereby determining the attention area EA, and by pressing the set key 76, the attention area is set.

The attention area EA has a size of approximately 21 squares, as shown in FIG. 10, for example, and the coordinates of each vertex thereof are input and transmitted to the CPU 26 via the communication system as necessary. Note that the size of the region of interest is equal to the storage capacity of the image RAM 403 in the monitor image memory circuit 201.

It is possible to easily calculate which line the attention area EA is located in as seen from the leading edge of the image, and in which pixel range in the main scanning direction the attention area EA is located.

The CPU 26 sets this range as a write area setting signal in the write area determination circuit 406.

The write area determination circuit 406 is configured in the main scanning direction (X direction).
A discrimination circuit 406a for discriminating the area and a sub-scanning direction (Y
It consists of a discriminating circuit 406b that discriminates the area in the direction (direction).

Each discrimination circuit 406a, b counts the dot crotter signal CKA or the horizontal synchronization signal Hsync while the image leading edge signal S5 is being input, and compares whether the count value is within the write area setting range.

If in the main scanning direction or in the sub-scanning direction, the signal S3 (low active WEX signal) or the signal S4 (low active WEY signal) becomes "L", respectively.

The write address generation counter 405 is the same as the write area determination circuit 406 described above (consisting of a counter 405a in the main scanning direction and a counter 405b in the sub-scanning direction,
One counter 405a outputs the dot clock signal CKA when the signal S3 from the discrimination circuit 406a is "L".
is counted and an address related to the main scanning direction is generated. The other counter 405b also outputs a horizontal synchronizing signal Hs when the signal S4 from the discrimination circuit 406b is "L".
ync is counted and an address related to the sub-scanning direction is generated.

Note that the address related to the main scanning direction (counter 405a
The contents of counter 405b) are cleared by the horizontal synchronization signal Hsync, and the address related to the sub-scanning direction (counter 405b
) is cleared by the image leading edge signal S5 generated by the CPU 26.

The address generated in this manner is input to the address terminal of the image RAM 403 via the selector 404.

By the way, the gate 409 receives the above-mentioned signals S3 and S4 and the dot clock signal S2 (CKA) through the inverter 4.
The signal S6 inverted by 10 and the data holding signal S7 from the CPtJ26 are input, and when it is within the write area range and the data holding signal S7 is "L" (active), the signal S6 is input to the gate 409. It will appear in the output.

Also, the signal S8 for switching between writing and reading is “
When the output of the gate 411 becomes "L" and the output of the inverter 412 becomes "H", the selector 404 selects the output of the write address generation counter 405, and the image RAM 403 selects the output of the write address generation counter 405. mode. Note that the output signal S13 of the inverter 412 is transmitted to the selection signal generation circuit 4 of the monitor image adjustment circuit 202, which will be described later.
It was also sent to the 25th.

Image data with gradation from the shading correction circuit 23 is input to the input/output terminal (I10 terminal) of the image RAM 403 via the selector 401 and the image selection circuit 402. The data are sequentially written to the designated addresses as described above in synchronization with the signal CKA.

As a result, the image of the attention area EA is stored in the image RAM 40.
Written in 3.

When writing to the image RAM 403 is completed, the CPU 2
6 sets the data holding signal S7 to "rH" and holds the written contents.

Next, reading from the image RAM 403 will be explained.

As shown in FIG. 11, the image of the attention area EA is made into a mosaic in which a total of 27 color adjustments have been made, 3 in the main scanning direction (X direction) and 9 in the sub scanning direction (X direction). It is assumed that the monitor image GM is output on one sheet of paper P. These images GM are output on paper P between coordinates XO and XI in the main scanning direction and between coordinates y0 and yI in the sub-scanning direction.

In this case, the method of reading out the image RAM M2O3 is to read out the contents of the same line three times in the main scanning direction of the image stored in the image RAM 403, and once all the contents have been read out in the sub-scanning direction, read out the image again. The data is read from the first line in the same manner as described above, and this is repeated nine times.

When reading the image RAM 403, the signal S8 from the CPU 26 becomes rH, which causes the selector 4 to
04 selects the output of the read address generation counter 407, the output of the inverter 412 becomes "L", and the image RAM 403 enters the read mode.

The readout area determination circuit 408 determines the readout area for the paper P. Like the write area determination circuit 406 described above, the readout area determination circuit 408 has a determination circuit 408a that determines the area in the main scanning direction (X direction) and a determination circuit 408a that determines the area in the subscanning direction ( It consists of a discrimination circuit 408b that discriminates the area in the X direction).

In each discrimination circuit 408a, b, if each count value is X or Y, then X0≦X≦X.

A coordinate value XOr x+ + yo + 71, which can be determined to be within the area range when the condition y0≧Y≧y1 is satisfied, is given in advance by a readout area setting signal.

When the output signals S9 (REX signal which is low active) and output signals 510 (REV signal which is low active) of each discrimination circuit 408a, b are both enabled,
An address is generated by the read address generation counter 407, and the image RAM is read according to the generated address.
The contents of 403 are read out and the held image data is output to the masking processing circuit 24.

At this time, the read address generation counter 407 is requested to count even if it exceeds its maximum value, but at that time, each generation counter 407a, b outputs an overflow signal Sll, S12 and starts counting again from the initial value. Start.

This overflow signal S11. Step S12 is sent to a monitor image tone setting circuit 202, which will be described later, and is used to switch the color correction coefficient.

Note that when reading the image RAM M2O3, the output of the image selection circuit 402 is in a high impedance state, and when the image RAM M2O3 is not being read, "white" image data is output to the subsequent stage. The selector 401 selects "white" data.

FIG. 5 is a circuit diagram of the monitor image tone setting circuit 202.

The monitor tone setting circuit 202 is a circuit that performs color correction (color adjustment) of a mosaic monitor image.

Color adjustment is performed by calculating Y, -, Y M, -, M C, -, , C for each print signal Y, M, C obtained by the calculation of equation (1) above. and adjusted print signals Y+ and M+.

The goal is to obtain C1. Here, k+ and kg are coefficients for adjustment.

In the mosaic monitor image GM shown in FIG. 11, the coefficient 1 for Y (yellow) does not change in the sub-scanning direction, but changes in the main scanning direction as 3'o, )'+, )'z, and M (magenta) coefficient kg does not change in the main scanning direction, and is m6. m.

+ m 2 + m o + m l ”・The coefficient of C (cyan) does not change in the main scanning direction, but changes as Co, C+, C! every 3 blocks in the sub-scanning direction. Change.

Therefore, in the monitor image tone setting circuit 202, the coefficients are changed for each of the print signals Y, M, and C as described above.

Now, the multiplier 421 receives the above-mentioned print signals Y, , M,
,C,. Here, in order to set three different coefficients in the main scanning direction, three latches Ll, L2 . A latch circuit 422 consisting of L3 is provided, and these latch circuits 422 include CP
The coefficients output from U26 are set.

The latch circuit 422 consisting of three latches was provided because
In the main scanning direction, the coefficient change period is short, and the CPU2
This is because it is difficult to set in real time using 6. Note that if it is desired to have n types of coefficients, n latches may be provided in parallel.

In the monitor image memory circuit 201 described above, the image RA
An overflow signal Sll in the main scanning direction generated when reading M2O3 is input to the selection signal generation circuit 424, and is input to the selector 423 via the selector 426 as a signal S21. Note that the selector 426
is adapted to transmit the output of the selection signal generation circuit 424 to the selector 423 in the mosaic monitor mode.

The selection signal generation circuit 424 generates the overflow signal 311
Each time LL is input, the selector 423 selects each latch LL,
L2. A signal is output that sequentially selectively switches L3.

As a result, each coefficient latched in the latch circuit 422 is selectively and sequentially sent to the multiplier 421.

Each latch LL, L2. The setting input of L3 is given a coefficient for a monitor image that is the next block in the sub-scanning direction.

Image RAM 403 in monitor image memory circuit 201
An overflow signal 312 in the sub-scanning direction generated when reading is input to a selector 427, and the selector 427 transmits this to the latch circuit 422 in the mosaic monitor mode. As a result, every time the overflow signal 512 is output, the latch circuit 422 latches and updates the manual data (coefficient) and outputs it to the multiplier 421 via the selector 423.

Therefore, when the block changes in the sub-scanning direction,
The set of coefficients is changed immediately.

After the mosaic monitor image is formed on the paper P, when the operator selects the image with the most desirable color among them,
The coefficients corresponding to the image of that color are automatically set, and the entire image of the document is thereby copied.

Here, the coefficient of color adjustment of the mosaic monitor image is the 11th
The CPU 26 stores information corresponding to each block in the figure.
When a block is selected, color adjustment is performed using the color adjustment coefficients of the selected block.

In order for the operator to specify an image selected from among the mosaic monitor images GM, for example, press the function keys 78 to 81 according to a message displayed on the display section 84.
All you have to do is operate the .

Alternatively, the image block shown in FIG. 11 is displayed on the display unit 84, and a coefficient is selected by selecting block coordinates using a function key or numeric keypad.

(Superimpose Mode) Next, the superimpose mode for performing image composition, which is a feature of the present invention, will be explained.

In the superimpose mode, image data registered (stored) in advance in the image RAM 2 O 3 is read out, and this registered image is printed (formed) at an arbitrary position on the paper P.

To register an image in the image RAM 403, operate the jigog dials 82 and 83 to register a specific area (same as the area of interest EA), as explained in the mosaic monitor mode above.
This is done by setting this and writing it into the image RAM 403 as image data with gradation.

Images other than the specific area are formed by printing the original image on the paper P by normal copying immediately after reading and writing to the image RAM 403 while prohibiting image formation in the specific area.

Printing of original images (images other than specific areas) and registered images (
Printing of the image of a specific area) can be performed in one printing process, except when the copying magnifications of the two images are different as described later.

When forming a document image, image formation in a specific area is prohibited by switching the image selection circuit 402 according to the read operation of the image RAM 403 (in the case that image composition is performed in one printing process), or as described below. Selector 4
15 is switched and "white" data is output (when the original image and the registered image are formed in separate printing processes), respectively.

A composite image is formed by printing the registered image read from the image RAM 403 in the superimpose mode on the prohibited portion of the specific area of this original image.

When forming an image read from the image RAM 403, that is, when forming a registered image, if this is performed in a process different from the printing process of the original image, the image RAM 403
In an image area other than the image from , the selector 401 is switched and "white" data is output.

In the superimpose mode, the selector 401 selects "white" data, the selector 426 selects the selection signal generation circuit 425, and the selector 427 selects the latch signal from the CPU 26.

Next, the operation of the monitor image memory circuit 201 shown in FIG. 4 in the superimpose mode will be described.

The registration of images in the image RAM 403 is exactly the same as in the mosaic monitor mode as described above.

When reading from the image RAM 403, a value corresponding to the desired writing position on the paper is set in the read area determination circuit 408 using a read area setting signal.

In this case, the output signal S9. of the read area determination circuit 408. SIO are both enabled (rl.

”), the output of the gate 411 becomes active, and direct image data from the image RAM 403 can be transmitted to the subsequent stage.

When reading from the image RAM 403 is not performed, the selector 401 selects a normal image from the shading correction circuit 23 and transmits this to the subsequent stage.

Next, the color adjustment operation in the superimpose mode of the monitor image tone setting circuit 202 shown in FIG. 5 will be explained.

Coefficients for color correction of the original image and coefficients for color correction of the registered image are respectively set for latches L1 and L2 of the latch circuit 422.

At this time, the selector 427 transmits a latch signal from the CPU 26 to the latch circuit 422, and the input data (coefficients) of the latch circuit 422 are latched by this latch signal.

Further, the selector 427 selects the output of the selection signal generation circuit 425.

In this selection signal generation circuit 425, when the output of the inverter 412 is "H", that is, when the image RAM 403 is not in the read state, the selector 423 selects the latch L1, and when the image RAM 403 is in the read state, the selector 423 selects the latch L2. You can now choose.

Therefore, when directly printing the original image without storing it in the image RAM 403, color adjustment is performed by the coefficient set in the latch L1, and the image (registered image) once stored in the image RAM 403 is read out and printed. In this case, color adjustment is performed using the coefficient set in latch L2.

Note that the set values of the latches LL and L2 must be reset for each print color.

Next, a case in which magnification is applied in superimpose mode will be explained.

FIG. 7 is a block diagram showing the configuration of the signal processing section 20a taking magnification control into consideration.

This signal processing section 20a and the signal processing section 2 of FIG. 3 mentioned above.
The difference from No. 0 is that an electric scaling circuit 210 and a sub-scanning clock generator 211 for scaling are added, and the other components are the same, so a description thereof will be omitted.

The electric variable magnification circuit 210 electrically performs enlargement/reduction in the main scanning direction, and the method and circuit configuration thereof are well known, so a description thereof will be omitted.

Furthermore, scaling in the sub-scanning direction is realized by varying the speed of relative movement between the document and the scanner 10, and since this configuration and control method are well known, their explanation will be omitted.

Figure 8 shows a monitor image memory circuit 2 that takes magnification control into consideration.
01a is a circuit diagram.

The difference between this monitor image memory circuit 201a and the monitor image memory circuit 201 shown in FIG. In addition, as the clock input to the read address generation counter 407, the sub-scanning clock S14 for scaling from the sub-scanning clock generator 211 for scaling is provided instead of the horizontal synchronizing signal Hsync.
This is what happened. Regarding other parts, the same parts as those of the monitor image memory circuit 201 in FIG. 4 are given the same reference numerals, and the description thereof will be omitted.

When outputting the original image to the masking processing circuit 24 regardless of reading and writing of the image RAM 403, the selector 415 replaces the image data from the image selection circuit 402 with respect to that part in order to prohibit image formation in a specific area. Outputs "white" data.

In other words, the trimming control signal is "L",
And the output signal (S13) of the inverter 412 is rL
J (when the image RAM 403 is in the read state), the output of the gate 416 becomes "L" and the selector 415 selects "white" data.

At this time, the readout area setting signal input to the readout area determination circuit 408 is based on the magnification of the original image and the image RAM 4.
The sub-scanning clock S14 for variable magnification, which is input to the readout area determination circuit 408b in the sub-scanning direction, is configured to give coordinate values that take into account the difference in magnification of the image read from 03. This corresponds to the magnification in the sub-scanning direction given to the scanner 10 that performs scanning.

FIG. 9 is a block diagram showing the configuration of the sub-scanning clock generator 211 for scaling.

The counter 441 counts in synchronization with the dot clock signal CKA from the clock generator 27, and outputs a triple carry when the count value reaches a set initial value. This ripple carry is the sub-scanning clock S14 for variable magnification.

The ripple carry is input to the load terminal, and each time the ripple carry is output, the data stored in the initial value data storage section 442 is loaded, thereby setting the initial value to the counter 441.

The data in the initial value data storage section 442 is set by the CPU 26, and a predetermined magnification in the sub-scanning direction is set based on the value. If the initial value is made equal to the number of dot clock signals CKA during one period of the horizontal synchronizing signal Hsync, the sub-scanning clock 314 for scaling is equal to the number of dot clock signals CKA during one period of the horizontal synchronizing signal Hsync.
The period is the same as c.

When the circuit described above performs one printing process using the necessary colors (up to four colors) on the original image, the paper P has the following:
For example, as shown in FIG. 12a, a document image FD is formed in which the specific area EB is blank.

Next, with the "white" data selected by the selector 401, the image registered in the image RAM 403 is read out, and the paper P has a specific area EB as shown in FIG.
A registered image FR is formed.

At this time, the sub-scanning clock S14 for scaling is inputted to the sub-scanning direction generation counter 407b of the read address generation counter 407, and the image from the image RAM 403 is enlarged to a predetermined magnification or Printed in reduced size.

The original image FD and the registered image FR are formed on the same sheet P held by the transfer drum 51, and a composite image as shown in FIG. 12C is formed.

Further, the original image FD and the registered image FR are independently color-corrected by the monitor image tone setting circuit 202, and a composite image whose color is adjusted according to the operator's preference is formed.

In the above embodiment, the original image FD and the registered image FR
We have explained the case where the images are printed at different magnifications, but if the magnifications of both images are equal to each other,
A composite image can be formed by a single printing process without having to perform two printing processes.

Furthermore, in the above-described embodiment, the blank specific area EB in the original image FD and the registered image FR have the same size, but the image may be distorted due to positional error of the image formed on the paper P. In order to prevent overlapping, the registered image FR may be made smaller than the specific area EB.

According to the above embodiment, in the mosaic monitor mode, when the attention area EA is set by operating the jitter dial 82 or 83 while looking at the display section 84, various different color corrections are performed on the attention area EA. A large number of mosaic monitor images GM are arranged and formed on the same paper P in one printing process.

The operator selects the image closest to the color of the original image or the image of the operator's favorite color from among the mosaic monitor images GM and specifies it using function keys 78 to 81 to set the color for the next copying operation. The adjustment is performed, and thereby the color adjustment for the entire image of the document can be easily performed.

Therefore, copying for color adjustment only needs to be done once, so paper and color toner are not wasted, and time and labor for color adjustment can be reduced.

Furthermore, by specifying an image selected from among the mosaic monitor images using function keys 78 to 81, the coefficients for color adjustment are automatically set.
This saves the effort of inputting coefficients numerically, and prevents coefficient setting errors.

According to the above-mentioned embodiment, in the superimpose mode, since the image of a specific area is stored in the image RAM 403 as image data having gradation, color correction cannot be performed when this is read out. can. Therefore, by once registering an image in the image RAM 403, it is possible to perform color adjustment as needed later, and especially when the image is a full color image, color adjustment with other images to be combined is made easy. It can be carried out. Furthermore, when the registered image is enlarged or reduced, the image does not deteriorate as would occur if it were registered using binary values.

In the embodiment described above, since the transfer drum 51 is provided, an image can be transferred onto the same sheet any number of times without separating the sheet from the transfer drum 51. Therefore, in the superimpose mode, it is possible to read the image registered in the image RAM 403 multiple times to form a plurality of registered images FR on the paper P, and also to register another image in the image RAM M2O3,
It is also possible to form different registered images FR on the paper P.

This allows three or more images to be combined.

According to the above-described embodiment, the image RAM 403 is used in both the mosaic monitor mode and the superimpose mode, so the image RAM 403 is effectively used, the utilization rate of resources is improved, and it is advantageous in terms of cost. Become.

〔Effect of the invention〕

According to the present invention, another image stored in the image memory means can be combined with a predetermined area of a document image.

At that time, since the image is stored in the image memory means as image data with gradation, color correction can be performed on the image data read out from there, and color adjustment can be easily performed. is possible.

It is possible to share the image memory means for image composition with the image memory means for color adjustment, for example, and in this case, the image memory means can be used effectively and the operating rate can be improved.

[Brief explanation of the drawing]

The drawings show embodiments of the present invention; FIG. 1 is a front view showing the overall configuration of the copying machine, FIG. 2 is a diagram showing the arrangement of various keys on the operation panel, and FIG. 3 is a diagram showing the configuration of the signal processing section. 4 is a circuit diagram of the monitor image memory circuit, FIG. 5 is a circuit diagram of the monitor image tone setting circuit, FIG. 6 is a timing chart showing the flow state of image data, and FIG. 7 is a signal processing unit. 8 is a circuit diagram showing another embodiment of the monitor image memory circuit, FIG. 9 is a circuit diagram of the sub-scanning clock 314 generator for variable magnification, and FIG. 10 is a display diagram. FIG. 11 is a diagram showing an example of paper on which a mosaic monitor image has been formed, and FIGS. 12 a' to 12 c are diagrams showing the state of image formation when performing image composition. 10...Scanner, 20.20a...Signal processing section,
26... CPU, 31... Print head section, 41
... Photoreceptor drum, 45a, 45b, 45c, 45c
m...Developer, 51...Transfer drum, 7B, 79,
80.81...Function key, 82.83...
・Jigog dial, 84...display section, 201, 20
1 a...Monitor image memory circuit, 202...Monitor image setting circuit, 401...Selector, 402...
Image selection circuit, 403... Image RAM, 415...
Selector, 421... Multiplier, 422... Latch circuit, P... Paper, EA... Attention area (specific area),
EB...Specific area, FD...Document image, FR...
Registered image. Figure 9 Figure 12

Claims (1)

[Claims] (1) means for making a predetermined area a blank area for the image data of the original image; image memory means for storing the image of a specific area in the original image as image data having gradation; A digital color copying machine comprising means for forming an image in the blank area using image data read from a memory means.