JP2773188B2 - Digital color copier - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a digital color copying machine having a mosaic monitor function.

(Prior Art) A digital color copier includes a reading unit that reads a document using a color image sensor and converts it into a print output signal, and a printer unit that prints an image on paper in accordance with the print output signal by electrophotography. When printing out a plurality of colors, the reading unit reads a document and prints an image on the same paper by the printer unit on a color-by-color basis.

The reading unit generally includes a masking circuit, and generates a signal whose color has been corrected in accordance with the printing characteristics of an output device (such as a printer).

The color-corrected image is printed in this way, but it is difficult for the masking circuit to keep the color difference between the original and the copy very small for all colors on the original. Therefore, when a copy is copied as a document, the color tone may be significantly changed from that of the document.

However, in a limited chromaticity range, a change in color tone can be suppressed relatively small by performing color adjustment (color balance).

However, in the past, color adjustment was performed by cut-and-try by taking a copy for each color adjustment, and scanning for the number of adjustment times × the number of print colors was repeated, which wasted in terms of time and cost. was there.

Accordingly, the present applicant has proposed a color adjustment selection method (hereinafter, referred to as a mosaic monitor) for reducing the time and cost required for color correction in another application. In this method, an area (attention area) including a part (for example, a face) where the user particularly wants to emphasize color reproduction is set by means for setting a specific area, and image data of the attention area is stored in the image memory means. . Next, color correction is performed on the image data read from the image memory means at various predetermined different color correction levels, and these are printed at different positions on the same sheet in one printing step. The user selects an image closest to the color of the original image or an image of a color desired by the user from among images (mosaic monitor images) of a plurality of regions of different colors with different tones printed on one sheet of paper. . Next, the entire document is copied based on the color correction level value of the selected image. In this way, a copy with the color adjustment desired by the user can be easily obtained.

(Problems to be Solved by the Invention) The mosaic monitor has not been able to easily copy the color adjustment desired by the user.

However, if, for example, the image of the color adjustment desired by the user is within the range of the mosaic monitor image, the user
The operation of the mosaic monitor must be repeated with different color correction levels until a satisfactory color tone is obtained. in this case,
Scanning of the image reading of the attention area of the document must be performed again. In particular, when a faithful reproduction such as a portrait skin color is desired, the color adjustment is often repeated many times.

In a color copying machine, the color tone may also change with time. Due to this change with time, the color adjustment level that was initially at an appropriate level substantially changes. It is preferable that the change over time of the color tone can be adjusted at the user level.

SUMMARY OF THE INVENTION An object of the present invention is to provide a digital color copying machine having a mosaic monitor mode capable of quickly adjusting to a desired color adjustment.

(Means for Solving the Problems) A digital color copier according to the present invention prints a plurality of images at different positions on the same paper by performing different color correction operations on image data of a certain area in a document image. Then, in a digital color copying machine having a mosaic monitor mode in which a user selects a desired image from the plurality of images, a predetermined operation is performed on a standard value of a plurality of stages of color correction coefficients used for the color correction operation. After the standard value setting by the standard value setting unit, the standard value setting unit that sets the color correction coefficient of the desired image selected by the user to the standard value for the next color correction operation, An instruction unit for instructing the printing of the plurality of images again is provided.

(Operation) In a digital color copying machine, a print signal (multi-value) corresponding to each print color (for example, yellow, magenta, cyan) is obtained from R, G, B image signals (multi-value) read by an image sensor. Y, M, C are required. In the color correction calculation, the product of the print signal and the color correction coefficient is obtained. The adjusted print signal is binarized for printing.

In the mosaic monitor mode, a multi-stage (for example, three-stage) color correction coefficient is used for each print color. The color correction coefficient is obtained by performing a predetermined calculation on the standard value by the color correction coefficient calculation means. For example, a predetermined adjustment value is added to or subtracted from the standard value to obtain a three-stage color correction coefficient.

The standard value is set by the standard value setting means so that the color correction coefficient of the desired image (that is, the desired color tone) selected by the user from the plurality of images printed in the mosaic monitor mode is a standard value for the next color correction operation. Is set.

Hereinafter, embodiments of the present invention will be described in the following order with reference to the accompanying drawings.

(A) Configuration of a digital color copier (b) Mosaic monitor (c) Image tone setting circuit (d) Registered image memory circuit (e) Flow of copy control related to mosaic monitor mode This is a part related to the standard value setting (FIG. 11) of the sections b), (c) and (e).

(A) Configuration of Digital Color Copier A digital color copier according to the present invention reads a document using an image sensor and converts the document into a print output signal. And a printer unit for printing images. When printing out a plurality of colors, reading of an original by the reading unit and printing of an image on the same paper by the printer unit are performed in a sequential manner for each color.

FIG. 1 shows the overall configuration of a digital color copying machine according to an embodiment of the present invention.

The scanner 10 includes an exposure lamp 12 for irradiating a document, a rod lens array 13 for collecting light reflected from the document, and a contact type CCD color sensor (image sensor) 14 for converting the collected light into an electric signal. Have. Scanner 10
When reading an original, the original 11 is driven by the motor 11 to move in the direction of the arrow, and scans the original placed on the platen 15. The image of the document surface illuminated by the light source 12 is
Is photoelectrically converted.

The R, G, B electrical signals (multi-valued) obtained by the CCD color sensor 14 are converted by the signal processing unit 20 into any one of yellow, magenta, cyan, and black print output signals (2
) And stored in the buffer memory 30. In the print head unit 31, the LD drive circuit 32 causes the semiconductor laser (LD) 33 to blink according to the print signal from the buffer memory 30 (see FIG. 2).

As shown in FIG. 1, the laser beam generated by the semiconductor laser 33 exposes the photosensitive drum 41, which is driven to rotate, via a reflecting mirror 37. As a result, an image of the original is drawn on the photoconductor of the photoconductor drum 41. The photoreceptor drum 41 is irradiated by an eraser lamp 42 before being exposed for each copy, charged by a charging charger 43, and further irradiated by a sub-eraser lamp 44. When exposure is performed in this state, an electrostatic latent image is formed on the photosensitive drum 41. Yellow, magenta, cyan, and black toner developing units 45
Only one of a to 45d is selected to develop the electrostatic latent image on the drum. The developed image is transferred to a paper wound around a transfer drum 51 by a transfer charge 46.

Normally, such a printing process is repeated for yellow, magenta, cyan and black. At this time, the scanner 10 repeats the scanning operation in synchronization with the operations of the photosensitive drum 41 and the transfer drum 51. Thereafter, the paper is separated from the transfer drum 51 by operating the separation claw 47, is fixed through the fixing device 48, and is discharged to the discharge tray 49.

The paper is fed from the paper cassette 50, and the leading end thereof is chucked by the chucking mechanism 52 on the transfer drum 51, so that no positional deviation occurs during transfer.

Next, referring to FIG. 2, a signal processing section 20 for processing an output signal of the CCD color sensor 14 and outputting a binary image signal will be described.

When outputting a normal image, the image signal photoelectrically converted by the CCD color sensor 14 is converted into an image density by the log amplifier 21 and then converted into a digital value (multi-value) by the A / D converter 22. . The multi-level converted R, G, B image signals are
The shading correction circuit 23 performs shading correction. In the mosaic monitor mode or the like, the signal subjected to shading correction is stored in the registered image memory circuit 1. When outputting a normal color image, the registered image memory circuit 1 is canceled, and the signal subjected to shading correction is sent to the masking processing circuit 24.

In the above processing, three colors of R, G, and B are processed in parallel. Next, the masking processing circuit 24 generates a signal of any print color (any one of yellow, magenta, thin ann, and black) from the three input signals in accordance with the characteristics of the print toner in order to perform the printing in the frame sequential manner. Which print color is to be generated is determined by a control signal from the CPU 25. When the color adjustment is changed in the mosaic monitor mode or the normal mode, the print signal is subjected to color correction by the image tone setting circuit 2. In the case of a normal image, the image tone setting circuit 2 is canceled and no color correction is performed. The electric variable power circuit 26
A signal from the masking processing circuit 24 or the image tone setting circuit 2 is electrically processed to electrically change the magnification in the main scanning direction. The technique is well known, and a description thereof is omitted here. On the other hand, zooming in the sub-scanning direction
Can be realized by making the speed of the relative movement of the variable.

The halftone processing circuit 27 converts the signal from the electric scaling circuit 26 into two.
The binarization processing is performed to generate a binary pseudo halftone signal, which is sent to the buffer memory 30. LD drive circuit 32 is a buffer memory
The semiconductor laser 33 is driven in response to the pseudo halftone signal from 30 to emit a laser beam.

The clock generator 28 generates a horizontal synchronization signal Hsync and a clock signal CKA for synchronizing reading of the CCD color sensor 14 and image data processing of each circuit. In addition, the scaling sub-scanning clock generator 29 generates a scaling sub-scanning clock which is an interrupt signal to the registered image memory circuit 1 in accordance with a signal from the CPU 25.

The CPU 25 transmits and receives signals to and from an operation panel (see FIG. 4). Further, signals are transmitted and received to and from a printer control unit (not shown) for controlling the printing operation.

In the signal processing section 20, the image data is processed at the timing as shown in FIG. Here, the horizontal synchronization signal Hsyn
c and the clock signal CKA are generated by the clock generator 28, and the R, G, B image data from the CCD color sensor 14 flows serially in synchronization with the clock CKA (the figure of the image data is mainly Indicates the address in the scanning direction.) Each time the horizontal synchronization signal Hsync is generated, the line n in the main scanning direction is updated. That is, the scanner 10 has advanced by a unit distance in the sub-scanning direction.

This digital color copying machine has a color adjustment function called a mosaic monitor and a superimpose function. Since both functions require a memory for storing image data and also have many common points in image processing, the registered image memory circuit 1 for image registration / readout and the image tone setting circuit 2 for color adjustment are shared. , And both functions are controlled by the CPU 25. Note that the superimpose function has been disclosed in another application filed by the present applicant, and a detailed description thereof will be omitted.

FIG. 4 is a diagram showing an arrangement of various keys and the like on an operation panel 70 provided on the upper surface of the copying machine.

The operation panel 70 includes a print start key 71 for starting a copying operation, an interrupt key 72 for designating an interrupt copy,
Clear / stop key 73, all reset key 74, numeric keypad 75, set key 76, cancel key 77, various function keys 78 to 81, jog dials 82 and 83 for setting areas to be described later, and original images for setting areas And a display unit 84 made of a liquid crystal or the like for displaying various messages. Here, the function keys 78, 79, and 80 are a mosaic monitor selection key, a superimpose mode selection key, and a density correction key, respectively.

The setting of a region such as a region of interest in the mosaic monitor mode described later is performed as follows. For example, when setting an attention area, as shown in FIG.
And a preliminary scan performed by the scanner 10, the document image is roughly displayed in the document area ED of the display unit 84 of the operation panel 70. The intersection of the vertical and horizontal instruction lines LPY and LPX is the center of the area EA. When the jog dials 82 and 83 are operated, these indicating lines move left and right or up and down, respectively, so that the area EA is determined, and by pressing the set key 76, the attention area is set.

(B) Mosaic monitor The mosaic monitor is realized by a registered image memory circuit (see section (d)) 1 for storing a region of interest and an image tone predetermined circuit (see section (c)) 2 for performing color adjustment in a printing process. Is done.

When the function key 78 is pressed on the operation panel 70, the mosaic monitor mode is selected.

The mosaic monitor indicates a region of interest where the user wants to perform color reproduction best, and the image of the region of interest is printed simultaneously on the same paper in various colors according to the instruction. This is a color adjustment selection method for selecting an optimum color tone from among the mosaic monitor images) and monitoring the color tone so that the optimum color adjustment is obtained from the mosaic monitor image.

In the mosaic monitor mode, first, the user
A preliminary scan of the document is performed, and a document area by the preliminary scan displayed on the display unit 84 of the operation panel 70 is viewed, and a region of interest (for example, a perspective portion in FIG. 5) where color adjustment is best performed is set. Correspondingly, the registered image memory circuit 1
Stores only image data I corresponding to the set value of the attention area in the next scan in the memory. Note that an upper limit is set for the size of the attention area in accordance with the storage capacity of the memory.

Next, the image tone setting circuit 2 prints the image data of various colors from the image data I read from the registered image memory circuit 1 and becomes the print color data by the masking processing circuit 24 on the same paper. generate kI (k = Ky, Km, Kc). Where Ky, Km, and Kc are yellow, magenta,
The color correction coefficient k for cyan. FIG. 6 shows an example of the output format. In this example, cyan (c),
Magenta (m), using a yellow color correction coefficients of the three printing colors with three _{(y) Ky = y i,} Km = m i, Kc = c i (i = 0,1,2), 3 × 3 × 3 = 27 types of images are output. Here, the color correction coefficients c ₁ , m ₁ and y ₁ with “1” represent standard coefficients for color adjustment. On the other hand, the color correction coefficients c ₀ , m ₀ , y _{0 to which} “1” and “2” are added; c ₂ , m
_2, y ₂ are each greater coefficient and standard coefficients c _1, m _1, y ₁ is less than the coefficient is obtained by performing a predetermined operation on the standard of the color correction coefficients _{c 1, m 1, y 1} .

In the present embodiment, the color correction coefficients c _i , m _i , y _i (i = 0,2) are
A predetermined color correction adjustment value a is subtracted from and added to the standard value c ₁ , m ₁ , y ₁ of the color correction coefficient of each printing color. By this calculation, the color correction count is set as follows.

y ₀ ← y ₁ −a y ₂ ← y ₁ + am ₀ ← m ₁ −am ₂ ← m ₁ + a c ₀ ← c ₁ −a c ₂ ← c ₁ + a 27 types of output images shown in Fig. 6 , The user selects an optimal color tone. Normally, this ends the mosaic monitor mode.

By the way, in order for the user to specify an image to be selected from the mosaic monitor image GM, for example, the function keys 78 to 81 may be operated according to a message displayed on the display unit 84 of the operation panel 70. .

Alternatively, the image block shown in FIG. 6 may be displayed on the display unit 84, and the block coordinates may be designated by using the function keys or numeric keys to select the counting.

Next, the original is read again, and an image is printed in the set color tone.

On the other hand, the feature of the present invention is that when there is no image of the desired color adjustment even when the mosaic monitor image is viewed, the image closest to the desired image is selected (FIG. 11, S61), and the mosaic is again performed centering on the image. A monitor image can be printed (Fig. 11, S93
And YES). That is, the color correction coefficient of the selected image is stored as the standard value y ₁ , m ₁ , c ₁ of the color correction without immediately ending the mosaic monitor mode after the first printing of the mosaic monitor image (No. ₁ ). (11 FIG. S92), another color complementary coefficient is obtained based on the standard value, and the mosaic monitor image is printed again.

Further, the reference value thus changed may be set as an initial value for the next mosaic monitor (S111 in FIG. 11). In this way, the color correction coefficient of the image faithfully reproducing the original in the mosaic monitor image can be used for the next printing, so that it is possible to adjust, for example, a color change over time at the user level.

(C) Picture Tone Setting Circuit FIG. 7 is a circuit diagram of the picture tone setting circuit 2.

The image tone setting circuit 2 is a circuit for performing color correction (color adjustment) of a mosaic monitor image provided at the next stage of the masking processing circuit 24.

The masking processing circuit 24 converts the image signals of the three colors R, G, and B into image signals (print signals) Y, M, C, and Y for printing corresponding to the respective print colors of yellow, magenta, cyan, and black.
The image signal is converted to K, and the converted image signal is output to the image tone setting circuit 2.

As is well known, a conversion formula for converting the original image signals R, G, B into print signals Y, M, C is expressed as follows.

The conversion coefficients a _{00 to} a ₂₂ are preset to appropriate values by theory and experiment so that an image of a color as close as possible to the original image is printed.

The color adjustment in the image tone setting circuit 2 is based on the calculation of Y ₁ = Ky × Y M ₁ = Km × M C ₁ = Kc × C for each of the print signals Y, M, and C obtained by the above calculation. That is, the adjusted print signals Y ₁ , M ₁ , and C ₁ are obtained. Here, Ky, Km, and Kc are color correction coefficients for yellow, magenta, and cyan, respectively.

Note that the black print signal K is output only for pixels that are printed in all three print colors of Y, M, and C. Also, no color adjustment is required.

In the mosaic monitor mode, a different set of color correction coefficients is given to each block as illustrated in FIG. That is, the read area specified by P ₀ (x ₀ , y ₀ ) and P ₁ (x ₁ , y ₁ ) is divided into blocks of three columns in the main scanning direction X and nine rows in the sub-scanning direction Y, Different combinations are set for each classification. In this case, the coefficient Ky of Y (yellow) does not change in the sub-scanning direction Y, but changes in the main scanning direction X to y ₀ , y ₁ , y _2, and the coefficient Km of M (magenta) becomes It does not change in the scanning direction X, and m ₀ , m ₁ , m ₂ , m ₀ , m _{1 for} each block in the sub-scanning direction Y
.., And the coefficient Kc of C (cyan) does not change in the main scanning direction, but changes to c ₀ , c ₁ , c ₂ every three blocks in the sub-scanning direction.

Therefore, the image tone setting circuit 2 sets the coefficient for color correction for each block of the mosaic monitor image for each of the print signals Y, M, and C in the mosaic monitor mode as described above, and outputs the adjusted print signal. Output.

In the image tone setting circuit 2, a multiplier 301 executes calculation for obtaining the print signal Y _1, M _1, C ₁ of the above. Here, a latch circuit 305 including three latches 302, 303, 304 is provided to set three coefficients in the main scanning direction in the mosaic monitor mode.
In 304, a coefficient output from the CPU 25 is set. These three coefficients are values corresponding to three blocks in the main scanning direction, respectively. Each time a sub-scanning clock for zooming is input to the CPU 25 as an interrupt signal, an interrupt process (see FIGS. 13 (a) and 13 (b)) is performed, and every time the block advances by one block in the sub-scanning direction. The CPU 25 outputs a latch signal to the image tone setting circuit 2 and causes the latches 302, 303, and 304 to latch new three coefficients for the next block.

The reason for providing the latch circuit 305 including the three latches 302 to 304 is that the coefficient change cycle is short in the main scanning direction,
This is because setting in real time by the CPU 25 is difficult in terms of speed.

The image memory 401 in the above-described registered image memory circuit 1
The overflow signal X in the main scanning direction generated at the time of reading is input to the first selection signal generation circuit 311. The first selection signal generation circuit 311 receives the overflow signal X every time (each block). And the selector 306 outputs a signal for selectively switching each of the latches 302 to 304 sequentially. In the mosaic monitor mode, the selector 312 outputs the output S21 of the first selection signal generation circuit 311 to the selector 306.
Tell

The selector 306 selectively sends the coefficients latched in the latch circuit 305 corresponding to the signal S21 to the multiplier 301 for each block.

On the other hand, in the registered image memory circuit 1, the image memory 401
The overflow signal Y in the sub-scanning direction generated at the time of reading is input to the selector 313.
Is a latch circuit in the mosaic monitor mode.
Tell 305. Thus, each time the overflow signal Y is output, the latch circuits 302 to 304 latch and update the set of color correction coefficients output from the CPU 25. Therefore, when a block changes in the sub-scanning direction, the set of color correction coefficients changes immediately.

When a color correction coefficient is selected in the mosaic monitor mode, the selected coefficient may be set in, for example, the latch 302 and output to the multiplier 301.

In superimpose mode, the selector 312
The description of selecting the output of the second selection signal generation circuit 314 and making it possible to make the color tone different between the superimposed region and the other region is omitted.

(D) Registered image memory circuit The registered image memory circuit 1 registers the registered image of the attention area of the document in the mosaic monitor mode in the memory 401,
A circuit for reading and printing at an arbitrary designated position on a sheet for printing a mosaic monitor image.

FIG. 8 shows a circuit diagram of the registered image memory circuit 1. Here, the memory 401 is a RAM for registering a registered image. The selector 421 selects the image data subjected to the shading correction and the 'white' data. When reading and printing the mosaic monitor image, 'white' data is selected. Level 42
The output signal of 1 is sent to the memory 401 and the selector 446 via the 3-state buffer 422. The 3-state buffer 422 enters the high impedance state only when the memory 401 is being read during printing of the mosaic monitor image (（= “1”). In other cases, when the mosaic monitor image is not printed in the mosaic monitor mode, 'white' data is output. When registering an image in the mosaic monitor mode, image data is output.

When the registered image is a full-color image, color adjustment is often required. Therefore, the selector 446 and the 3-state buffer 422 interpose a memory before the intermediate processing and store the multi-value data in the memory. By reading the registered image data, the mosaic monitor image can be printed with various color adjustments.

The writing area determining circuit 402 determines whether the writing area is in the writing direction in the main scanning direction or the sub scanning direction based on the writing area setting signals in the main scanning direction (X) and the sub scanning direction (Y) set by the CPU 25. It is determined whether or not. The AND gate 407 outputs the clock ▼ to the 端子 terminal of the memory 401 when it is in the writing area based on the determination result, and enables writing to the memory 401.

Similarly, the read area determination circuit 408 determines whether or not the read area exists in the main scan direction or the sub scan direction based on the read area setting signal in the main scan direction (X) in the sub scan direction (Y) set by the CPU 25. (The read area is determined by the output format.) The AND gate 405 determines whether the inverter 423
Outputs '0' to the ▲ ▼ terminal of the memory 401 via
Make the memory 401 readable.

The write and read addresses for the memory 401 are
These are generated by the write address generation counter 403 and the read address generation counter 409, respectively, and output to the address terminal of the memory 401 via the selector 404. Selector 404
Selects a write address or a read address depending on whether writing or reading is performed. Each of the write address and the read address is generated as a one-dimensional address using a multiplier and an adder based on the address in the X direction and the address in the Y direction.

The selector 446 and the AND gate 448 are provided to output “white” data to the superimposed image portion when printing the original image in the superimposed mode, but detailed description thereof will be omitted. Except for the case where the trimming signal is output in the superimpose mode, the selector 446 selects the 3-state buffer 422 or the memory 401
Select the output signal of

Hereinafter, the registered image memory circuit 1 will be described in more detail.

In writing a registered image, when the user specifies a region of interest, the CPU 25 determines that this region is (Y
The number of pixels in the main scanning direction (X direction) is calculated, ie, the coordinates of the upper left corner of this area (x ₀ , y ₀ ) and the right Find the coordinates (x ₁ , y ₁ ) of the lower corner,
A write area setting signal for determining the write area in the direction is set in each of the X section 402a and the Y section 402b of the write area determination circuit 402. X and Y indicate the main scanning direction and the sub-scanning direction, respectively. X section 402a and Y section 402b of write area determination circuit 402
Counts the horizontal synchronizing signal Hsync and the clock CKA when the image leading edge signal is input, and compares whether or not the count value is within the writing area setting range. If the main scanning direction is within the range (x ₀ ≦ x ≦ x ₁ ), ▲ ▼ =
'L' is output, and if the sub-scanning direction is within the range (y ₀ ≤ y ≤ y ₁ ), ▼ = 'L' is output. The write address generation counter 403 generates a write address when the write area determination circuit 402 determines that the area is the write area, and sends the write address to the address terminal of the memory 401 via the selector 404. That is, in the X section 403a of the write address generation counter 403, ▲ ▼
When = L, the clock CKA is counted to generate an address in the main scanning direction. This address is cleared by the horizontal synchronization signal Hsync. When Ｙ = “L”, the Y section 403b of the write address generation counter 403 counts the horizontal synchronization signal Hsync and generates an address in the sub-scanning direction. This address is cleared by the image leading edge signal generated by the CPU 25. The write address generation counter 403 includes a multiplier and an adder (not shown), and calculates a one-dimensional address from both addresses in the X and Y directions.

When the image data is written to the memory 401 that has generated the address in this manner, the data holding signal is further set to “L”, Is set to 'L'. This allows the selector 404
Receives the selection signal via the AND gate 405, selects the address signal from the write address generation counter 403, and transmits it to the address terminal of the memory 401. Further, the clock ▼ is transmitted to the 端子 terminal of the memory 401 via the inverter 406 and the AND gate 407, thereby enabling writing to the memory. Also Is set to 'L', the 3-state buffer 42
2 is the AND gate 40 only when the original image can be written.
5 and becomes active state, and the image data is
Tell the O terminal. This allows the memory 401 to store only the image of the area determined by the writing area determination circuit 402 to be within the range in both the main and sub scanning. When writing is completed, the CPU 25 sets the data save signal to 'H',
Writing is prohibited via the gate 407, and the contents of the memory 401 are retained.

When reading the data stored in the memory 401, it is necessary to read the data so that the data is printed in a designated read area. The circuit configuration required for reading is almost the same as that for writing. The CPU 25 sets x ₀ ≦ x ≦ x ₁ in the X section 408a and the Y section 408b of the read area determination circuit 408 for determining the read area on the sheet, in consideration of the original reading magnification and the printing magnification, respectively.
previously given set value can be determined to be within the scope when y is ₀ ≦ y ≦ y _1. x ₀ , y ₀ X coordinate and Y of upper left corner P ₀ of readout area
X ₁ and y ₁ are the X and Y coordinates of the lower right corner P ₁ (see FIG. 6). The read area determination circuit 408 receives a horizontal synchronization signal Hsync when an image tip signal is input during scanning.
And counts the clock CKA and compares whether the count value is within the readout area setting range. If the main scanning direction is within the range, ▼ = “L” is output, and if the sub-scanning direction is within the range, ▼ = “L” is output.

The read address generation counter 409 is provided in the read area determination circuit 4
When it is determined that 08 is a read area, a read address is generated. Is “H”, it is sent to the address terminal of the memory 401 via the selector 404. That is, the read address generation counter
X section 409a of 409 is clock CKA when ▲ = 'L'
And generates an address in the main scanning direction. This address is cleared by the horizontal synchronization signal Hsync. Also, Y section 409 of read address generation counter 409
b counts the sub-scanning clock from the scaling sub-scanning clock generator 29 when ▲ = “L” and generates an address in the sub-scanning direction. Counting the sub-scanning clock instead of the horizontal synchronizing signal Hsync takes into account magnification. This address is cleared by the image leading edge signal generated by the CPU 25. In the read address generation counter 409, a one-dimensional address is generated from the addresses in the main scanning direction and the sub-scanning direction using a multiplier and an adder (not shown).

Data read by accessing the memory 401 is transmitted to the subsequent stage. At this time, naturally, in the read area, a count request is made even if the read address counter 409 exceeds the maximum size of the memory. In this case, the X section 409a and the Y section 409b of the read address counter overflow each time they overflow. Signals X and Y are output, and counting starts again from the initial value. Overflow signal
X and Y are output to the image tone setting circuit 2 arranged at the subsequent stage. The overflow signals X and Y are used when a plurality of images are arranged in the horizontal direction and printed with different color tones in the mosaic monitor mode.

At the time of reading, Is 'H', the read area ▲ ▼ = 'L',
▲ ▼ = 'L') AND gate 405 and inverter 423
, The memory 401 is in an output enabled state, the 3-state buffer 422 is in a high impedance state via an AND gate 405, and the image data input side is the memory 40.
It is separated from one.

The selector 466 selects the data to be read from the memory 401 by a selection signal via the AND gate 448 when the memory 401 is readable (▲ ▼ = 'L'). Since it is necessary to read the data so as to be able to print in a format, the "white" data is selected in order to make the image data "white" except for reading the data from the memory. At this time, the read area determination circuits 408a and 408
In b, coordinates are set in consideration of the difference between the original reading magnification and the printing magnification of the contents of the memory 401. In the variable magnification sub-scanning clock used for printing, the magnification is set to be equal to the original reading magnification at the same magnification.

If you want to output a 3 × 9 image using the example in FIG. 6,
As a method of reading the memory, if the contents of the same line are read three times in the main scanning direction and all the contents are read in the sub-scanning direction, the main scanning direction is read again from the beginning.

X of a read area determination circuit for determining a read area for a sheet
Section 408a and Y section 408b can be output (▲ ▼ =
'L'), X part 409a, Y part 409b of read address generation counter
The address is generated, the memory 401 is accessed using the address, and the held image data is transmitted to the subsequent stage via the selector 446. Here CPU25, when the X portion 408a of the read area determination circuit, is _{x 0 ≦ x ≦ x 1,} Y portion
408b is provided with a set value that can be determined to be within the read range when y ₀ ≦ y ≦ y ₁ . At this time, the read address generation counter 409 sets the maximum size of one block (= (x ₁
When −x ₀ ) / 3) is exceeded, the overflow signal X is output, and counting is started again from the initial value. Then, the contents of the same line are read. This is repeated three times. Moving forward by (y ₁ −y ₀ ) / 9 in the sub-scanning direction, 3
The reading of the block is completed, and an overflow signal Y is output. Thus, three images are printed in the horizontal direction. This is repeated nine times in the sub-scanning direction to obtain 3 × 9
Is read out.

In the image setting circuit 2, different color correction coefficients are set for each block corresponding to the overflow signals X and Y (see FIGS. 13 (a) and 13 (b)). Different color adjustments are made and printed.

(E) Flow of Copying Machine Control in Mosaic Monitor Mode FIG. 9 shows a main flow in the superimposing function of the copying operation control of the CPU 25 for controlling the digital color copying machine and the mosaic monitor mode. When the function key 78 or 79 is pressed on the scanning panel 70 to enter the superimpose mode or the mosaic monitor mode, the main flow is entered. Normally, to select the mosaic monitor mode is "YES" for both the image registration request (step S1, hereinafter "step" is omitted) and the mosaic monitor output request (S3). Selecting the superimpose mode means that the image registration request (S1) and the superimpose mode output request (S5)
Both are "YES".

If there is a request for image registration (YES in S1), image registration processing is performed (S2, see FIG. 10). Image registration refers to registering the content of an image in a specified area. In the image registration processing (S2), an area desired by the user is set, and the contents of the area are registered in the memory. In the area setting, a document image is read, the read image is displayed on the display unit 84, and a desired area is set with the jog dials 82 and 83 and the set key 76.

If it is a mosaic monitor output request (YES in S3), mosaic monitor output processing (S4, see FIG. 11) is performed. That is, the registered contents are read out, subjected to various color corrections, and output as a mosaic monitor image. At this time, the printing conditions such as the number of prints and the magnification are reset to initial values (all reset), and the density adjustment level is set to a standard value. When an image having a color balance desired by the user is selected from the output mosaic monitor images and a copy request is made, a copy operation is performed, and the entire image is selected based on the color balance.

In the case of a superimpose output request (YES in S5), superimpose output setting is performed (S6). That is, after checking whether there is a registered image, the setting for reading from the memory is performed. Next, when a copy request is made (YE in S7)
S), copying is performed (S8, S9), and the registered image is printed over the original image.

If there is no image registration request, mosaic monitor output request, or superimpose output request (NO in all of S1, S3, and S5), normal copying is performed (S7 to S9).

The setting of the area in the mosaic monitor mode and the superimpose mode is performed using the display unit 84 as described in the section (b).

FIG. 10 shows a flow of the image registration process (S2). When the set key 76 is pressed on the operation panel 70, the area setting value set on the display unit 84 at that time is input (S2
1). Further, other various input values are set (S22).

Next, it is determined whether or not to start image registration (S3
1). When starting image registration, the vertices of the registered image area (upper left corner and lower right corner) from the input area setting value (S21)
Is calculated, a writing area setting signal is output to read the original image in that area (S32), the basic signal is subjected to shading correction (S33), and the correction value is written to the memory 401 (S34). Then, clear the image registration request (S
35), return. When not starting image registration (S31
NO), immediately clears the image registration request (S35), and returns.

FIG. 11 shows a flow of a mosaic monitor output process (S4) which is a feature of the present embodiment. First, the memory 40 of the attention area
The conditions for reading out the contents of 1 are set (S51), and the color correction coefficients y _i , m _i , c are set based on the standard values y ₁ , m ₁ , c ₁ of the color correction coefficients and the adjustment value a.
_i (i = 0,2) is calculated (S52). That is, in this embodiment, the color correction adjustment value a is increased or decreased with respect to the standard value, and the color correction coefficient is set in three stages.

y ₀ ← y ₁ −a y ₂ ← y ₁ + am ₀ ← m ₁ −am ₂ ← m ₁ + a c ₀ ← c ₁ −a c ₂ ← c ₁ + a Then, read out the memory contents and calculate the color correction coefficient. The mosaic monitor image is set and printed (S53). Note that the standard values y ₁ , m ₁ , and c ₁ are set to initial values when the power is turned on, but values selected from a mosaic monitor image may be used (S92). Also, the initial value may be changed (S
111).

Next, when an image (block) desired by the user is selected from the mosaic monitor images on the display unit 84 (S61),
Set a color correction coefficient according to the selected image. First,
Color correction coefficient selected for yellow is determined whether y ₀ (S62), if y _0, the value of y ₀ and y ₁ (S63). Otherwise y _0, then the color correction coefficients selected is determined whether or not y ₁ (S64). go directly to S71 if y _1, unless y _1, the value of y ₂ to y ₁ (S
65). That, y ₁ where represents the color correction coefficient of the yellow selected.

Next, the color correction coefficient selected for magenta is m ₀ whether it is determined (S71), if m _0, the value of m ₀ m
_{It is set to 1} (S72). Otherwise m _0, then the color correction coefficient selected is whether m ₁ is determined (S73). If m ₁ Continue to S81, unless m _1, the value of m ₂ to m ₁ (S74). In other words, where m ₁ represents the color correction coefficients of the selected magenta.

Next, the color correction coefficient selected for cyan is determined whether c ₀ (S81), if c _0, the value of c ₀ c ₁
(S82). Otherwise c _0, then, are selected color correction coefficient whether c ₁ is determined (S83). go directly to S91 if c _1, unless c _1, the value of c ₂ to c ₁ (S84). That is, where c ₁ is representative of the color correction coefficients of the selected cyan.

Next, it is determined whether the selected color correction coefficient is set to a standard value (S91). At this time, as shown in FIG. 12, the display section 84 of the operation panel 70 displays "Do you want to set the selected color balance as a standard value?", And the user can select the jog dials 82 and 83. And YES or NO by the set key 76. When setting stores selected values y ₁ set in S62~S84 above, the m _1, c ₁ as the standard value (S92).

Next, it is determined whether or not to start the mosaic monitor mode (S93). For example, when the user wants to print a mosaic monitor image based on the standard value newly set in S92, a function key (mosaic monitor selection key) 78
Press to start. When the start is selected, S5
Return to 1 and perform mosaic monitor output. If the start is not selected, the process proceeds to S101.

When copying is requested print start key 71 is pushed (S101), the scanning of the original is started, to start the copy using the selected value y _1, m _1, c ₁ of set color correction coefficients ( S102). Then, copying is performed until the copying is completed (S103).

When copying is completed, then, stores selected values y ₁ of the color correction coefficient used for copying, a m _1, c ₁ as the standard value (S 111), the process returns. This standard value becomes the initial value of the color correction coefficient in the next mosaic monitor mode.

The user may be allowed to select whether to set the standard value as the initial value.

FIGS. 13 (a) and 13 (b) are flowcharts showing a process of setting a coefficient for color adjustment in printing a mosaic monitor image.

This processing is executed every time the horizontal synchronization signal Hsync is generated.
25 is interrupted, and this is executed as an interrupt routine.

In this, the counter Ct ₁ counts the distance in the sub-scanning direction from the leading end of the print sheet P (image top), to detect the end beginning printing of the mosaic monitor image GM and printing. The counter Ct ₂ counts the distance in the sub-scanning direction,
A change in a block of the mosaic monitor image is detected. T
Represents the distance in the sub-scanning direction from the leading edge of the image to the printing position of the mosaic monitor image, and l represents the distance of one block in the sub-scanning direction (see FIG. 6).

First, the state is determined in S300, and its value is set to “0” to
Branch according to “4”.

When the state is "0", whether the image tip (leading edge of the paper P) is determined (SS301), when the image leading edge has passed the counter Ct ₁ initializes (S302), the state "1" (S303).

When the state is "1", wait for the counter Ct ₁ is T (S311), i.e. waits for reaching the position of the coordinate y ₀ is the tip of the mosaic monitor image GM, then the developing device for use toner States "2",
Jump to either “3” or “4”.

That is, when it is Y (yellow) (YES in S312), the state is set to "2" (S313). M when (magenta) (YES in S321), the counter Ct ₂ initializes (S322), the conversion i to "0" (S323), the state is "3" (S324). When C of (cyan) (NO in S321), the counter Ct ₂ initializes (S331), the transformation j to "0" (S33
2) The state is set to "4" (S333).

State is at "2" (Y-scan) latches the y _0, y _1, y ₂ as a coefficient 1-3 to set each output a latch signal to the image tone setting circuit 2 latches 302, 303, 304 (S341), the counter wait for the ct ₁ (T + 9l), i.e. waits for reaching the position of the coordinate y ₁ is a rear end of the mosaic monitor image GM (S342), the state is set to "0" (S343).

When the state is "3" (M scan), the latch 30
By substituting m _i to the coefficient 1-3 2~304 (S351), the counter Ct
₂ Wait for the l, i.e. waits for one block of the mosaic monitor ends (S352), the counter Ct ₂ initializes (S353), increments by one the variable i (S3
54). Next, it waits until the rear end of the mosaic monitor image is reached (S355), and sets the state to "0" (S356). That is, here, the same value _mi is set for the coefficients 1 to 3, and each time the mosaic monitor image changes by one block in the sub-scanning direction, the coefficients 1 to 3 are changed to the new value _{mi + 1.} You.

When the state is "4" (C scan), the latch 30
C _j is substituted for coefficients 1 to 2 of 2 to 304 (S361), and the counter Ct
Wait for ₂ to become (3l), that is, wait for the end of three blocks of the mosaic monitor (S362), and count the counter Ct ₂
Is initialized (S363), and the variable j is incremented by one (S364). Next, it waits until the rear end of the mosaic monitor image is reached (S365), and sets the state to “0” (S366). That is, here, the same value c _j is set to the coefficients 1 to 3 of the latches 302 to 304, and each time the mosaic monitor image changes by three blocks in the sub-scanning direction, the coefficients 1 to 3 become new c _{j + 1} Is changed to

When the processing in each state is completed, the counters Ct ₁ and Ct ₂ are incremented (S371).

Through the above processing, various coefficients are set for each print color for each block, and color adjustment is performed.

(Effects of the Invention) Conventionally, when there is no image having the color balance desired by the user in the image that has been subjected to the mosaic monitoring, the mosaic monitor must be operated again, and the operation is complicated.

According to the present invention, when it is desired to print the mosaic monitor image again outside the range of the mosaic monitor image, the mosaic monitor image can be obtained again without scanning the original document centering on the image closest to the desired image. Therefore, a satisfactory color balance can be easily selected.

Further, the color balance can be adjusted at a user level with respect to a change over time.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a digital color copying machine. FIG. 2 is a block diagram of a signal processing unit. FIG. 3 is a timing chart of the image data processing. FIG. 4 is a plan view of the operation panel. FIG. 5 is a diagram of setting a region of interest. FIG. 6 is a diagram of an output format of a mosaic monitor image. FIG. 7 is a circuit diagram of an image tone setting circuit. FIG. 8 is a circuit diagram of a registered image memory circuit. FIG. 9 is a diagram showing a main flow relating to the mosaic monitor mode of the digital color copying machine. FIG. 10 is a flowchart of the image registration process. FIG. 11 is a flowchart of the mosaic monitor output setting. FIG. 12 is a diagram of a screen for setting a selection value to a standard value. FIGS. 13A and 13B are flowcharts of the interrupt processing. 1 ... registered image memory circuit, 2 ... image tone setting circuit, 20 ... signal processing unit, 25 ... CPU, 70 ... operation panel, 78 ... mosaic monitor selection key, 84 ... display unit, 401 ... …memory.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Shigeru Moriya 2-3-1-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Inside the Osaka International Building Minolta Camera Co., Ltd. (56) References JP-A-1-126607 (JP, A) JP-A 1-232878 (JP, A) JP-A 62-229426 (JP, A) JP-A 61-142427 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) ) B41J 2/525 G03G 15/01 H04N 1/46

Claims (1)

(57) [Claims] An image data of a certain area in a document image is subjected to different color correction operations to print a plurality of images at different positions on the same paper, and a user selects a desired image from among the plurality of images. In a digital color copying machine having a mosaic monitor mode for selecting a color correction coefficient, a color correction coefficient calculating means for performing a predetermined calculation on a standard value for a plurality of levels of color correction coefficients used for the color correction calculation; Standard value setting means for setting a color correction coefficient of an image to a standard value for the next color correction operation, and instructing means for instructing printing of the plurality of images again after setting the standard value by the standard value setting means. A digital color copier characterized by the following.