JPH07264424A - Color image printer - Google Patents

Abstract

PURPOSE:To reduce color slurring in both main and sub-scanning directions with simple and inexpensive configuration. CONSTITUTION:A color laser printer 3 prints out a test pattern color image onto recording paper. An image scanner 1 reads out the test pattern color image of the recording paper and gives the image to a data processor 2. The data processor 2 displays the test pattern image data and reference pattern image data read out of a 2nd storage means on a display device 4 overlappingly and a manipulated quantity of a mouse 5 for each color is fed to the color laser printer 3 as color slurring correction data for each color based on the manipulation of the mouse 5 to match the test pattern image with the reference pattern image for each color. The color laser printer 3 corrects an emission timing of a laser beam to a corresponding photosensitive drum from each laser unit based on the color slurring correction data for each color.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention processes color image data by processing image data read by an image scanner with a data processing device such as a personal computer, and prints the color image data on recording paper by a color laser printer. The present invention relates to a color image printing device for printing.

[0002]

2. Description of the Related Art A conventional multi-drum type color laser printer generally prints a color image on recording paper by the following method. First, based on the input color image data, a laser beam is emitted from a laser unit provided for each color such as yellow, cyan, magenta, or black to a corresponding photosensitive drum to form a latent image. Next, each latent image formed on each photosensitive drum is developed with a toner of a corresponding color by a developing unit provided for each color, and each toner image on each photosensitive drum is superposed on one sheet of recording paper. After transfer, it is fixed on the recording paper.

That is, there are three color laser printers.
Since the toner images of four colors or four colors are sequentially transferred onto one sheet of recording paper, if the printing positions of the toner images deviate from each other, the hue of the input color image data will differ. Or, in the worst case, the characters and the like become unreadable. Therefore, it is required that the overlay accuracy of each toner image is high, but for that purpose, the mounting position accuracy of the photosensitive drum or the laser unit provided for each color is required. However, since the mounting position accuracy of the photosensitive drum and the laser unit is determined by the mechanical accuracy, it cannot be expected so much. Further, since the photosensitive drum and the laser unit are inside the main body, and the space around them is also small, there is a limit to finely adjusting these positions manually.

Therefore, in the conventional color laser printer, the scanning direction of the laser beam onto the conveyed recording paper (the direction orthogonal to the conveying direction of the recording paper, hereinafter referred to as the main scanning direction) depends on the used color. A predetermined image is printed in each area divided by type, and a positional deviation detector such as a CCD is provided at a predetermined position in each area, and the relative positional deviation amount of each image according to the output of this positional deviation detector. Is calculated,
The color misregistration in the sub-scanning direction (recording paper conveyance direction) is reduced by correcting the laser beam writing timing on each photosensitive drum for a time corresponding to the relative positional misregistration amount (Japanese Patent Laid-Open No. Sho 62). -242969). In addition, a line type CC is provided on each side of each photoconductor.
D is provided, each CCD detects the deviation of the scanning point of the laser beam on each photoconductor, and the modulation start time of the laser beam based on the color image data is changed based on the detection result, so that the color in the main scanning direction is changed. There has been proposed a device for reducing the deviation (see Japanese Patent Laid-Open No. 63-65457).

[0005]

As described above,
Japanese Unexamined Patent Publication No. 62-242969 discloses a technique for reducing color misregistration in the sub-scanning direction.
Japanese Laid-Open Patent Publication No. 7-27 discloses a technique for reducing color misregistration in the main scanning direction. However, if these techniques are simply combined to reduce color misregistration in both the main scanning direction and the sub-scanning direction, the CCD A large number are required and the device becomes expensive. The present invention has been made under such a background, and an object thereof is to provide a color image printing apparatus capable of reducing color misregistration in both the main scanning direction and the sub scanning direction with an inexpensive and simple structure. And

[0006]

The invention according to claim 1 is
An image scanner that reads an image printed on recording paper and outputs image data, and a display are provided, and the image data supplied from the image scanner is processed and edited based on the operation of the operation means to create image data. An image supplied from the data processing device including a data processing device, a plurality of laser units provided for each of a plurality of colors, and a plurality of photosensitive drums provided corresponding to the plurality of laser units. Based on the data, a color laser printer that modulates a laser beam emitted from each laser unit to a corresponding photosensitive drum to print an image on a recording sheet, and a test pattern color image data including a test pattern for each color are stored. Reference pattern image including a first storage means and a reference pattern for each color corresponding to each test pattern And a second storage unit in which the data is stored, wherein the data processing device reads the test pattern color image data from the first storage unit and supplies the test pattern color image data to the color laser printer. The printer prints a test pattern color image on the recording paper based on the test pattern color image data supplied from the data processing device, and the image scanner prints the test pattern color image printed on the recording paper by the color laser printer. The image is read and the test pattern image data is output, and the data processing device superimposes the test pattern image data supplied from the image scanner and the reference pattern image data read from the second storage unit. Displayed on the display, each displayed on the display, Based on the operation of the operation means for matching the test pattern image and the reference pattern image for each color, the operation amount of the operation means for each color is supplied to the color laser printer as color misregistration correction data for each color, The laser printer is characterized by correcting the irradiation timing of the laser beam from each laser unit to the corresponding photosensitive drum based on the color shift correction data for each color supplied from the data processing device.

According to a second aspect of the present invention, an image scanner for reading an image printed on a recording sheet and outputting image data and a display are provided, and the image data supplied from the image scanner is used for operating the operating means. A data processing device that processes and edits based on this to create image data,
A plurality of laser units provided for each of a plurality of colors, and a plurality of photosensitive drums provided corresponding to the plurality of laser units, each based on the image data supplied from the data processing device, A color laser printer that modulates a laser beam emitted from a laser unit to a corresponding photosensitive drum to print an image on a recording sheet, and a first storage unit that stores test pattern color image data including a test pattern for each color. And a second storage unit that stores reference pattern image data including a reference pattern for each color corresponding to each test pattern, wherein the data processing device stores the test pattern from the first storage unit. The color image data is read and supplied to the color laser printer, and the color laser printer includes the data processing device. A test pattern color image is printed on a recording paper based on the test pattern color image data supplied from the image scanner, and the image scanner reads the test pattern color image printed on the recording paper by the color laser printer to obtain a test pattern image. The data processing device outputs the test pattern image data supplied from the image scanner and the second data processing device.
Based on the reference pattern image data read from the storage means, the difference between the center position of the test pattern for each color and the center position of the corresponding reference pattern is calculated,
Each calculation result is supplied to the color laser printer as color misregistration correction data for each color, and the color laser printer responds from each laser unit based on the color misregistration correction data for each color supplied from the data processing device. It is characterized in that the irradiation timing of the laser beam to the photosensitive drum is corrected.

[0008]

According to the first aspect of the present invention, the operator first causes the color laser printer to print a test pattern showing the current color misregistration state on the recording paper, and then causes the image scanner to print on the recording paper. Read the image of the test pattern. Next, the operator displays the image of the test pattern read by the image scanner and the image of the reference pattern stored in the second storage device on the display of the data processing device in an overlapping manner, and looks at the screen of the display. However, until the two images match, the operating means is operated to create the color shift correction data for each color. The color shift correction data for each color is supplied to the color laser printer, and the irradiation timing of the laser beam from each laser unit to the corresponding photosensitive drum is corrected, so that the color shift is corrected by a simple operation. Further, according to the invention described in claim 2, since the correction data of the color misregistration for each color is automatically created by the data processing device, the operation is further simplified as compared with the invention described in claim 1.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic view showing the arrangement of a color image printing apparatus according to the first embodiment of the present invention. In this color image printing apparatus, image data read by the image scanner 1 is processed and edited by operating a mouse 5 and a keyboard described later in a data processing apparatus 2 including a general-purpose computer such as a personal computer. The color laser printer 3 prints the color image data on the recording paper by creating new color image data by adding new data.

In FIG. 1, an image scanner 1 reads monochrome image data from its image reading surface. The main body 2a of the data processing device 2 has a CPU (central processing unit) that controls each part of the device and a ROM that stores various control programs used in the CPU.
And to load each control program, to store data while the control program is running, to store color image data, and to drive a floppy disk in which application programs are stored and various data are stored. It has a built-in floppy disk device. Further, the data processing device 2 has a display 4 such as a CRT display for displaying color image data and the like.
, A mouse 5, a keyboard (not shown) including a numeric keypad and function keys, and the like are connected.

Next, the mouse 5 will be described. In order for the operator to move the cursor displayed on the display 4 to select a menu or specify a position, the mouse 5 is moved on the table while looking at the display screen for a predetermined distance in the direction of the selected menu or the specified position. Mouse 5 when moved
Transfers mouse data corresponding to its own moving distance and moving direction to the CPU inside the data processing device 2. Thereby, the CPU moves the cursor displayed on the display 4 in a predetermined distance and direction according to the mouse data described above.

When the cursor reaches the menu to be selected or the position to be designated and the operator clicks the enter button of the mouse 5, the mouse 5 gives a signal indicating that the menu is selected, or the position is designated. The signal to the effect is transferred to the CPU. As a result, the CPU executes processing relating to the selected menu or the designated position.

Next, the structure of the color laser printer 3 will be described. 2 is a schematic diagram showing the mechanical configuration of the color laser printer 3, and FIG. 3 is a block diagram showing the electrical configuration thereof. This color laser printer 3 is, for example,
It is mainly used to create leaflets for retail stores such as supermarkets.
As disclosed in Japanese Patent Laid-Open No. 69-65457 and Japanese Patent Laid-Open No. 63-65457, the above-mentioned three primary colors or four primary colors are not printed in the same area and mixed to express an intermediate color. Three primary colors (black, red and blue in this embodiment) are printed in different areas. However, in the color laser printer 3 as well, similar to the conventional printer described above, when the positional relationship between the photosensitive drums and the recording paper is misaligned, color misregistration occurs, so that color misregistration is prevented. Of course there is a need.

2 and 3, the CPU 6 controls the R
RAM8 according to the control program stored in OM7
By performing processing using the working area of No. 2, each unit in the color laser printer 3 is controlled, and various data such as color image data is transmitted / received to / from the data processing apparatus 2 using the communication interface 9. RAM8
The color image data is temporarily stored in the color image data area.

The paper feed unit 10 is provided so as to partially project from the lower part of one end (lower part on the right side in FIG. 2) of the main body of the color laser printer 3 (hereinafter referred to as the printer main body), and a paper feed cassette 11 in which recording paper is stored. The recording sheet is placed on the conveyor belt 13 which is composed of a sheet feeding roller (not shown) or the like and which constitutes the conveying section 12 based on a sheet feeding command from the CPU 6. The transport unit 12 is provided in the lower portion inside the printer body, and includes the above-described transport belt 13, transport rollers 14 and 15, and the like.
The recording paper placed on the conveyor belt 13 is conveyed from the right side to the left side in FIG. 2 based on the conveyance instruction from U6.

The laser units 16 to 18 are for printing black, red and blue respectively, and are provided above the conveyor belt 13 inside the printer body at predetermined intervals along the conveyor direction of the conveyor belt 13. Has been. The photosensitive drums 19 to 21 are for printing black, red, and blue, respectively, and are provided near the upper portion of the conveyor belt 13 at predetermined intervals along the conveyance direction of the conveyor belt 13. Further, the developing units 22 to 24
Are for black, red, and blue printing, respectively, and are provided near the corresponding photosensitive drums 19 to 21 above the conveyor belt 13 at predetermined intervals along the conveyor direction of the conveyor belt 13.

The laser unit 16 modulates the laser beam oscillated by the internal laser oscillating unit 16a based on the black color image data and the print command supplied from the CPU 6, and outputs the modulated laser beam. ,
By irradiating the peripheral surface of the black photosensitive drum 19 which is provided at a facing position and rotates at a predetermined speed, while horizontally scanning in the main scanning direction (axial direction of the photosensitive drum 19) by a polygon mirror (not shown), Form a latent image. In this case, by synchronizing the rotation of the photosensitive drum 19 and the irradiation of the laser beam, the image of the color image data and the photosensitive drum 1 can be obtained.
The latent images formed on the peripheral surface of 9 can be made to correspond one to one. The developing unit 22 develops the latent image formed on the peripheral surface of the photosensitive drum 19 with black toner, and at the same time, develops the developed black toner image on the photosensitive drum 19.
The image is transferred onto the recording paper that is being conveyed by the conveyor belt 13 that is driven in synchronization with the rotation of the photosensitive drum 19.

The laser unit 17, the laser oscillator 17a, the photosensitive drum 20 and the developing unit 23, the laser unit 18, the laser oscillator 18a, the photosensitive drum 21 and the developing unit 24 are based on color image data for the former red. To form a red latent image on the photosensitive drum 20 and transfer the red toner image onto the recording paper, and the latter forms a blue latent image on the photosensitive drum 21 based on the blue color image data.
Except that the blue toner image is transferred onto the recording paper.
The laser unit 16, the laser oscillation unit 16a, the photosensitive drum 19, and the developing unit 22 operate in the same manner. However, the positions of the photosensitive drums 19 to 21 and the recording paper are aligned.

The recording paper on which the black, red, and blue toner images have been transferred is conveyed by the conveyor belt 13, and is fixed to the lower portion of the other end of the printer body (lower left portion in FIG. 2). The toner image is conveyed to the inside of the sheet 25, where the toner image is fixed, and a color image is formed on the recording paper. Next, the recording paper on which the color image is formed is discharged to the outside from the discharge opening 26 formed at the lower end of the other end of the printer body and placed on the discharge tray 27.

The processing for determining the value for correcting the color misregistration position for each color of the color laser printer 3 in the data processing apparatus 2 having such a configuration will be described with reference to the flowchart shown in FIG. Before performing this process, the operator first uses the test pattern shown in FIG. 5A on the recording paper with the color laser printer 3 in order to check the current color shift state and the amount of the color laser printer 3. Print it.

In FIG. 5A, black, red, and blue test patterns 28 to 30 are arranged in order from the left. Figure 5
The color image data for one sheet of recording paper of the test pattern shown in (a) is stored in advance in a predetermined area of the RAM of the data processing device 2, so that the operator can use the keyboard and mouse 5 of the data processing device 2. Is operated to read this color image data from the RAM and transfer it to the color laser printer 3 to print a color image of a test pattern on the recording paper. Since this test pattern printing process is the same as the conventional one, its explanation is omitted.

Next, when the operator operates the keyboard or mouse 5 of the data processing device 2 to put the data processing device 2 in the correction value determination mode, the CPU of the data processing device 2 operates as shown in FIG.
In step SA1, the image data of one reference recording sheet of the reference pattern stored in a predetermined area of the RAM (see FIG. 5B) is read out, and the image of the reference pattern is displayed on the display 4. To do.

In FIG. 5B, reference patterns 31 to 33 for black, red and blue are arranged in order from the left. The image data of the reference pattern and the color image data of the test pattern shown in FIG. 5A have a one-to-one correspondence between the relative addresses in each area of the RAM.
When the photosensitive drums 19 to 21 of the color laser printer 3 are accurately aligned with the recording paper, if the respective prints are made on the same recording paper, the test patterns 28 to 30 and the reference pattern 31 can be obtained. ~ 33 completely overlaps.

Next, the operator accurately positions the recording paper on which the test pattern is prepared, which is prepared before starting this process, on the image reading surface of the image scanner 1, and then instructs the image scanner 1 to read. Operate the switch or button. As a result, the image scanner 1 reads the test pattern printed on the recording paper from the image reading surface and converts the test pattern into monochrome image data, and then transfers the monochrome image data to the data processing device 2.

As a result, the CPU of the data processing device 2
Advances to step SA2 in FIG. 4, reads the monochrome image data transferred from the image scanner 1 and temporarily stores the monochrome image data in a predetermined area of the RAM, and then, step SA3.
Go to. In step SA3, a monochrome image of the test pattern stored in a predetermined area of the RAM is displayed on the display 4 so as to be superimposed on the image of the reference pattern displayed in the process of step SA1 and read in the process of step SA2 (see FIG. (See c)), the process proceeds to step SA4.

Therefore, the operator can visually understand the current state and amount of color misregistration in the main scanning direction and the sub-scanning direction for each color by looking at the screen displayed on the display 4. . Then, in order to correct the color misregistration, the operator uses the mouse 5 so that the test patterns 28 to 30 displayed on the display 4 and the reference patterns 31 to 33 respectively match, as described later.
To operate.

At step SA4, the CPU of the data processing device 2 determines whether or not the enter button of the mouse 5 has been clicked. If the result of this determination is "NO", the same determination is repeated. First, the operator operates the mouse 5 to move the cursor displayed on the display 4 within the reference pattern 31 for black and on the test pattern 28 for black in order to correct the color misregistration of black. Click the Confirm button to move and specify that position as the reference point. As a result, the determination result of step SA4 is “Y
ES ”, and the CPU of the data processing device 2 proceeds to step SA5.

Even if the confirm button of the mouse 5 is clicked when the cursor is in an inappropriate position, that is, in a position not on the black test pattern 28 within the reference pattern 31, the determination in step SA4 is made. The result is not "YES", and the determination in step SA4 is repeated until the enter button of the mouse 5 is clicked when the cursor is at the appropriate position.

In step SA5, the color designated by the reference pattern of the cursor when the confirm button of the mouse 5 is first clicked is discriminated and the color is stored in a predetermined register of the RAM. At the same time, the position of the cursor is used as a reference point of the color, and the position of the test pattern displayed on the display 4 at the reference point on the monochrome image of one sheet of recording paper, that is, in the RAM in which the test pattern is stored. After storing the relative address corresponding to the above-mentioned reference point in a predetermined register of the RAM, the process proceeds to step SA6.

In step SA6, in the monochrome image data of one recording sheet of the test pattern read in the process of step SA2 and stored in the predetermined area of RAM, it is stored in the predetermined register of RAM in the process of step SA5. Search for a range in which data having the same value as the data value stored at the relative address of the reference point continuously exists, that is, the shape and size of the image having the same luminance as the luminance of the reference point. Recognition. Next, after the relative address of the image obtained as a result of the above search is obtained and stored in a predetermined address of the RAM, the process proceeds to step SA7.

In step SA7, after moving the image, the process proceeds to step SA8. The movement of this image is performed by moving the cursor to the desired position while clicking the confirmation button of the mouse 5 and sliding the cursor to the desired position, and turning off the confirmation button at the desired position. Therefore, the CPU of the data processing device 2 moves the image recognized on the image data read in step SA2 to the display 4 based on the mouse data generated by the movement of the mouse 5 and the signal for confirming the movement position. Moves the displayed cursor and the specified image on the screen. The operator repeats the operation of the mouse 5 until, for example, the black test pattern 28 matches the corresponding reference pattern 31, and then turns off the enter button of the mouse 5.

In step SA8, the CPU of the data processing device 2 determines whether or not the confirmation button of the mouse 5 is turned off to input a signal for confirming the moving position of the image. If the result of this determination is "NO",
Return to step SA7. On the other hand, if the determination result in step SA8 is "YES", that is, if the confirmation button of the mouse 5 is turned off and a signal for confirming the moving position of the image is input, the process proceeds to step SA9. .

In step SA9, the relative address corresponding to the reference point of the designated color (black in this case) stored in the predetermined register of the RAM in the process of step SA5, and the enter button is turned off in step SA8. After the difference from the relative address of the RAM corresponding to the position of the cursor when the main scanning direction and the sub-scanning direction are obtained, R is set as the correction value data of the color designated in the process of step SA5.
After storing in a predetermined register of AM, step SA10
Go to.

In step SA10, it is determined whether or not the above-mentioned correction value data for all of black, red and blue has been stored in a predetermined register of the RAM.
If the result of this determination is "NO", the flow returns to step SA4, and the processes of steps SA4 to SA9 are performed for the next color. On the other hand, the judgment result of step SA10 is "YE
In the case of "S", that is, when the storage of the correction value data in the predetermined register of the RAM for all of black, red and blue is completed, the process proceeds to step SA11. In step SA11, the correction value data for each color stored in the predetermined register of the RAM in the process of step SA9 is sequentially transferred to the color laser printer 3 together with the data indicating that the color type data and the correction value data are stored. A series of processing ends. By the processing described above, the correction value data in the main scanning direction and the sub-scanning direction for each color are transferred to the color laser printer 3, so that the operation is simple, quick, and accurate.

Next, the CPU 6 of the color laser printer 3
The print / data storage process of will be described with reference to the flowchart shown in FIG. When the color image data or the correction value data transferred from the data processing device 2 is input through the communication interface 9, the printing / printing shown in FIG.
The data storage process starts. First, the CPU 6 proceeds to the process of step SB1 and determines whether or not the input data is correction value data based on the presence or absence of data indicating that it is correction value data. This judgment result is "YES"
In the case of, it progresses to step SB2.

In step SB2, the inputted correction value data is stored in a predetermined register of the RAM 8 for each color, and then a series of processing is terminated. On the other hand, step SB1
If the result of the determination is “NO”, that is, if the input data is color image data, then step SB
Go to 3. In step SB3, the paper feed command is given to the paper feed unit 10, the carry command is given to the carry unit 12, and each laser unit 16 is sent.
After starting each part such as transferring the print command to ~ 18,
Go to step SB4. As a result, the paper feeding unit 10 takes out the recording paper from the paper feeding cassette 11 and places it on the transport belt 13, the transport unit 12 transports the recording paper by the transport belt 13, and the laser units 16 to 18 respectively. The rotation of the polygon mirror is started at the timing.

In step SB4, the black correction value data stored in the predetermined register of the RAM 8 is read out, and then the process proceeds to step SB5. At step SB5, since the rotation of the photosensitive drum 19 and the scanning of the laser beam modulated by the black color image data are synchronized,
After the black correction value data read in the process of step SB4 is converted into the time data in the main scanning direction and the time data in the sub scanning direction, the timing of transferring the black color image data to the laser unit 16 is corrected. And CP
U6 advances to step SB6. In step SB6,
After transferring the black color image data to the laser unit 16 at the timing corrected in the process of step SB5,
Go to step SB7.

As a result, the laser unit 16 is
Based on the black color image data transferred from U6, the laser beam of the laser oscillation unit 16a is modulated, and the modulated laser beam is applied to the peripheral surface of the black photosensitive drum 19 that rotates at a predetermined speed. A latent image is formed by irradiating a polygon mirror (not shown) while horizontally scanning in the main scanning direction. The developing unit 22 develops the latent image formed on the peripheral surface of the photosensitive drum 19 with black toner, and conveys the developed black toner image on the photosensitive drum 19 by the conveyor belt 13. Transfer it to the recording paper.

In step SB7, the red correction value data stored in the predetermined register of the RAM 8 is read out, and then the process proceeds to step SB8. In step SB5, the red correction value data read in the process of step SB7 is converted into time data in each of the main scanning direction and the sub scanning direction, and then the timing of transferring the red color image data to the laser unit 17 is corrected. . And CPU
In step 6, the process proceeds to step SB9. In step SB9, the red color image data is transferred to the laser unit 17 at the timing corrected in the process of step SB8, and then the process proceeds to step SB10.

As a result, the laser unit 17 is
Based on the red color image data transferred from U6, the laser beam of the laser oscillator 17a is modulated, and the modulated laser beam is applied to the peripheral surface of the red photosensitive drum 20 rotating at a predetermined speed. A latent image is formed by irradiating a polygon mirror (not shown) while horizontally scanning in the main scanning direction. The developing unit 23 develops the latent image formed on the peripheral surface of the photosensitive drum 20 with red toner and conveys the developed red toner image on the photosensitive drum 20 by the conveyor belt 13. The black toner image is transferred onto the recording paper.

In step SB10, the blue correction value data stored in the predetermined register of the RAM 8 is read out, and then the process proceeds to step SB11. In step SB11, the blue correction value data read in the process of step SB10 is converted into time data in each of the main scanning direction and the sub scanning direction, and then the timing of transferring the blue color image data to the laser unit 18 is corrected. . Then, the CPU 6 proceeds to step SB11. Step S
At B11, the blue color image data is converted to step SB1.
Laser unit 18 at the timing corrected by the process 1
After transferring to, the series of processing is ended.

As a result, the laser unit 18 is
The laser beam of the laser oscillator 18a is modulated based on the blue color image data transferred from U6, and the modulated laser beam is applied to the peripheral surface of the blue photosensitive drum 21 rotating at a predetermined speed. A latent image is formed by irradiating a polygon mirror (not shown) while horizontally scanning in the main scanning direction. The developing unit 24 develops the latent image formed on the peripheral surface of the photosensitive drum 21 with blue toner and conveys the developed blue toner image on the photosensitive drum 21 by the conveyor belt 13. The black and red toner images are transferred onto the recording paper.

The recording paper on which the black, red and blue toner images have been transferred is carried by the carrying belt 13 and carried inside the fixing unit 25 where the toner images are fixed and a color image is formed on the recording paper. Is formed.
Next, the recording paper on which the color image is formed is discharged to the outside from the discharge opening 26 formed at the lower end of the other end of the printer body and placed on the discharge tray 27.

As described above, according to the first embodiment described above, the color laser printer 3 inputs the correction value data for each color transferred from the data processing device 2, and based on the correction value data. By adjusting the toner image formation timing on each of the photosensitive drums 19 to 21, the color misregistration is reduced.

Next, a second embodiment of the present invention will be described. The second embodiment has the same configuration and operation as each part of the color image printing apparatus of the first embodiment described above, except for the color-based position correction value determination processing of the CPU of the data processing device 2 described later. Next, with reference to the flowchart shown in FIG. 7, description will be given of a process of determining a value for correcting the position of the color shift of each color of the color laser printer 3 in the data processing device 2. Before performing this process, the operator first checks the current color misregistration state of the color laser printer 3 and the amount thereof, as in the first embodiment.
The test pattern shown in FIG. 5A is printed on the recording paper by the color laser printer 3.

Next, the operator accurately positions the recording paper on which the test pattern is printed on the image reading surface of the image scanner 1, and then operates a switch or button for instructing the reading of the image scanner 1. . As a result, the image scanner 1 reads the test pattern printed on the recording paper from the image reading surface and converts the test pattern into monochrome image data, and then transfers the monochrome image data to the data processing device 2.

Then, when the operator operates the keyboard or mouse 5 of the data processing device 2 to put the data processing device 2 into the correction value determination mode, the CPU of the data processing device 2 proceeds to the processing of step SC1 in FIG. Image scanner 1
Read the monochrome image data transferred from the RAM
After being temporarily stored in a predetermined area of, the process proceeds to step SC2. In step SC2, among the monochrome image data of one recording sheet of the test pattern read in the processing of step SC1 and stored in the predetermined area of the RAM, FIG.
After searching for data having the same value or a value close to the value of the data of the black test pattern 28 in the position corresponding to the black reference pattern 31 shown in (4), the process proceeds to step SB3.

In step SC3, a range in which data having the same value or a value close to the data searched in the process of step SC2 continuously exists, that is,
After recognizing the shape and size of the black image, the process proceeds to step SC4. In step SC4, step SC
After the relative address of the RAM at the center position of the image obtained by the process of 3 is obtained and stored at a predetermined address of the RAM, the process proceeds to step SC5.

In step SC5, the center of the reference pattern of the corresponding color (black reference pattern 31 in this case) in the image data of one recording sheet of the reference pattern stored in the predetermined area of the RAM. The relative address of the RAM corresponding to the position is calculated, and the difference between the calculated result and the relative address of the RAM at the center position of the image stored in the predetermined register of the RAM in the process of step SC4 is calculated in the main scanning direction and the sub scanning direction. And then stored in a predetermined register of the RAM as black correction value data, and then step SC6
Go to.

In step SC6, it is determined whether or not the correction value data described above for all of black, red and blue has been stored in a predetermined register of the RAM. If the result of this determination is "NO", then the processing returns to step SC2 and the processing of steps SC2-SC5 is performed for the next color. On the other hand, the judgment result of step SC6 is "YES".
In the case of, that is, when the storage of the correction value data for all of black, red and blue in the predetermined register of the RAM is completed, the process proceeds to step SC7. Step S
In C7, the correction value data for each color stored in the predetermined register of the RAM in the process of step SC5 is sequentially transferred to the color laser printer 3 together with the color type data and the data indicating the correction value data, and then a series of Ends the process. By the processing described above, the correction value data in the main scanning direction and the sub-scanning direction for each color is transferred to the color laser printer 3 without the operator operating the mouse 5, so the first embodiment described above is used. It is easier and quicker to operate and more accurate than.

The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to this embodiment, and the design change and the like without departing from the gist of the present invention. Even so, it is included in the present invention. For example, in the above-described first and second embodiments, an example in which the image scanner 1 uses monochrome image data is shown, but the present invention is not limited to this. You may use. In this case, since the image recognition only needs to search the color data, it is possible to cope with a large color shift.

Further, in the above-described first embodiment, each of the reference patterns 31 to 33 and each of the test patterns 28 to 30.
If and are enlarged and displayed on the screen, each test pattern 2
The operation of matching 8 to 30 with each of the reference patterns 31 to 33 becomes easier. Furthermore, in the above-described first embodiment, an example in which the CPU of the data processing device 2 determines the color for correcting the color misregistration in the process of step SA5 of FIG. 4 is shown, but the present invention is not limited to this, and the operator May be specified and designated by the mouse 5 or the keyboard. In this case, a large color shift can be dealt with.

In addition, in the above-described first and second embodiments, an example in which the present invention is applied to a color image printing apparatus for printing black, red, and blue leaflet advertisements is shown. And the configuration of the device is not limited to these examples. For example, even when the color laser printer 3 is used alone, the data processing device 2 and the image scanner 1 may be connected to the color laser printer 3 only when the color misregistration is corrected.

Further, in the above-mentioned first and second embodiments, as shown in FIG. 5, an example using the square test pattern and the reference pattern is shown, but the present invention is not limited to this, and the test pattern is not limited to this. Any shape may be used as long as the positional deviation between the reference pattern and the reference pattern is clear. Further, in the first and second embodiments, the correction value data for each color obtained by the data processing device 2 is sequentially transferred to the color laser printer 3 together with the color type data and the data indicating the correction value data. However, the present invention is not limited to this. For example, the data processing device 2
In step 1, after obtaining the correction value data for each color, the image data to be printed is created by shifting the position for each color based on the correction value data for each color, or the image data once created is set for each color. You may make it shift. In this case, the irradiation timing of the laser beam emitted from the laser oscillators 16a to 18a of the laser units 16 to 18 of the color laser printer 3 is automatically corrected in the data processing device 2.

[0055]

As described above, according to the present invention,
A detector for detecting a color shift, which has been conventionally required, is unnecessary, and it is possible to reduce color shifts in both the main scanning direction and the sub-scanning direction with an inexpensive and simple configuration.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a configuration of a color image printing apparatus according to first and second embodiments of the present invention.

FIG. 2 is a schematic diagram showing a mechanical configuration of a color laser printer 3.

FIG. 3 is a block diagram showing an electrical configuration of a color laser printer 3.

FIG. 4 is a flowchart showing a color-based position correction value determination process of the CPU of the data processing device 2 according to the first embodiment of the present invention.

FIG. 5 is a diagram for explaining the operation of the embodiment of the present invention.

FIG. 6 is a flowchart showing a print / data storage process of a CPU 6 of the color laser printer 3.

FIG. 7 is a flowchart showing a color-based position correction value determination process of the CPU of the data processing device 2 according to the second embodiment of the present invention.

[Explanation of symbols]

 1 image scanner 2 data processor 3 color laser printer 4 display 5 mouse 6 CPU

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Claims (2)

[Claims] 1. An image scanner for reading an image printed on a recording sheet and outputting image data, and a display. The image data supplied from the image scanner is processed / edited based on the operation of an operating means. And a plurality of laser units provided for each of a plurality of colors and a plurality of photosensitive drums provided corresponding to the plurality of laser units. A color laser printer that modulates the laser beam emitted from each laser unit to the corresponding photosensitive drum based on the image data supplied from the printer to print an image on the recording paper, and a test pattern color consisting of a test pattern for each color It comprises a first storage means for storing image data and a reference pattern for each color corresponding to each test pattern. Second storage means in which the quasi-pattern image data is stored, the data processing device reads the test pattern color image data from the first storage means and supplies the test pattern color image data to the color laser printer. The color laser printer prints a test pattern color image on a recording sheet based on the test pattern color image data supplied from the data processing device, and the image scanner prints a test image printed on the recording sheet by the color laser printer. The pattern color image is read and test pattern image data is output, and the data processing device receives the test pattern image data supplied from the image scanner and the reference pattern image data read from the second storage unit. The display is overlaid and displayed on the display. On the basis of the operation of the operating means for matching the test pattern image for each color and the reference pattern image displayed on the color laser printer, the operation amount of the operating means for each color is used as color misregistration correction data for each color. The color laser printer corrects the irradiation timing of the laser beam from each laser unit to the corresponding photosensitive drum based on the color misregistration correction data for each color supplied from the data processing device. Color image printing device. 2. An image scanner for reading an image printed on a recording paper and outputting image data, and a display, wherein the image data supplied from the image scanner is processed / edited based on an operation of an operation means. And a plurality of laser units provided for each of a plurality of colors and a plurality of photosensitive drums provided corresponding to the plurality of laser units. A color laser printer that modulates the laser beam emitted from each laser unit to the corresponding photosensitive drum based on the image data supplied from the printer to print an image on the recording paper, and a test pattern color consisting of a test pattern for each color It comprises a first storage means for storing image data and a reference pattern for each color corresponding to each test pattern. Second storage means in which the quasi-pattern image data is stored, the data processing device reads the test pattern color image data from the first storage means and supplies the test pattern color image data to the color laser printer. The color laser printer prints a test pattern color image on a recording sheet based on the test pattern color image data supplied from the data processing device, and the image scanner prints a test image printed on the recording sheet by the color laser printer. The pattern color image is read and test pattern image data is output, and the data processing device outputs the test pattern image data supplied from the image scanner and the reference pattern image data read from the second storage unit. Based on the center position of the test pattern for each color, The difference between the center position of the reference pattern is calculated, each calculation result is supplied to the color laser printer as color misregistration correction data for each color, the color laser printer, for each color supplied from the data processing device. A color image printing apparatus, which corrects the irradiation timing of a laser beam from each laser unit to a corresponding photosensitive drum based on the color misregistration correction data.