JP2001277599A - Image position shift self-adjustment method, device thereof, and recording medium on which the method is programmed and recorded - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To improve the accuracy of the printing position of each color by measuring the image position shift amount, and to perform the self-adjustment of the image position shift amount. An inspection apparatus 1 generates and outputs a plurality of single-color L-shaped patterns prepared for each color material (YMCK) used in a printing process with regularity, and outputs a single-color L-shaped pattern output by a device to be inspected. The patterns are sequentially read via the measurement scanner 5, captured as red, green, and blue signals, and the relative coordinate position of each single-color L-shaped pattern with respect to the reference L-shaped pattern is measured and compared with a predetermined ideal relative coordinate position. The color shift of the monochromatic L-shaped pattern in the main scanning direction and the sub-scanning direction is inspected. Also, by measuring the amount of displacement in the main scanning direction and the sub-scanning direction of each single-color L-shaped pattern, an adjustment amount is calculated so as to minimize the amount of displacement, and the printing timing based on the calculated adjustment amount is determined. Make adjustments.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for self-adjustment of image position deviation for inspecting and adjusting the position accuracy of a color image among image qualities reproduced by a copying machine or a printer, and a program for the method. And a recording medium to be recorded.

[0002]

2. Description of the Related Art With the spread of office automation (OA), various types of information devices output image information such as characters and images in offices. This typical one is
It is a copying machine for copying a document, and a printer for outputting data processed by the information processing apparatus main body.

The above-described copying machine or printer forms an electrostatic latent image on a photosensitive drum and reads and develops image information using an image pickup device such as a CCD, or uses a recording head such as a thermal head to perform development. To print images on paper.

[0004] When such information equipment is designed, manufactured and shipped at a factory, a reproduced image is inspected. Recently, color copying or color recording has become popular, and it is necessary to inspect images of these. When the inspection target is a color image, reproduction of a color other than the predetermined color is performed by mixing some colors. That is, when a color image is printed in an electrostatic copying machine or a thermal transfer type printer, black B is applied to the three color materials of cyan (C), magenta (M), and yellow (Y). Added 4
An image is formed using a color material. When printing is performed by successively superimposing such color materials, the amount of color misregistration as one factor that affects color reproducibility becomes a problem. That is, if color misregistration occurs in the process of reproducing colors for each color, the quality of the image will be significantly degraded, especially in the case of line drawings and characters.

[0005]

As described above, in a color printing apparatus, printing is performed using toners and inks of KCMY four colors, and colors are synthesized by superimposing CMY colors. If the positions of the colors to be superimposed are shifted in this synthesis process, a color different from the original color is synthesized, and the quality of the image is remarkably deteriorated especially in a line drawing or a character portion.

For example, blue characters are reproduced by mixing the primary colors of magenta and cyan. If the positions of these two colors are shifted during the printing process, the characters are blurred and very difficult to read. Further, in the case of a picture image, the effect of misregistration appears on the printed picture itself, and there is a problem that accurate color reproduction cannot be performed.

Therefore, conventionally, the amount of color misregistration has been measured for a reproduced image. Conventionally, such a color shift amount is measured by a method in which a color image to be inspected is magnified and projected using a microscope, and an inspector directly reads the color shift. Alternatively, a pattern as a non-inspection object may be cyan, magenta, yellow,
An inspection pattern is prepared in which black color materials are sequentially adjacent to each other and arranged on a straight line, and the inspection pattern is read by a computer to detect the maximum value of the amount of color misregistration of the image. I was going to do an inspection.

However, according to the former, since the inspector is the main subject, the measurement value or the test result changes when the inspector is different, and also the psychological level based on the mental fatigue and physical fatigue of the inspector. The effect was reflected in the measured values and inspection results, making accurate measurement or inspection difficult. According to the latter, although measurement and inspection are automated, there is a difference between the measured amount of color shift and the sense of color shift when an actual color image is visually observed, and human Inspection of the amount of color misregistration accurately corresponding to vision was impossible.
In addition, according to the latter, since the inspection is performed using an inspection pattern in which each color material is sequentially adjacent and arranged on a straight line, there is a disadvantage that only one of the main scanning direction and the sub-scanning direction can be measured and inspected. I was

The present invention has been made in view of the above circumstances, and a plurality of single-color L-shaped inspection patterns prepared for each color material used in a printing process are adjacently generated and output with regularity, and the output inspection is performed. The pattern is read by a scanner to calculate the amount of misalignment, measure the amount of misalignment in the main scanning direction and sub-scanning direction, and compare with the standard value to calculate the amount of adjustment and perform self-adjustment so that it is within the standard. It is an object of the present invention to provide a self-adjusting method of image position deviation, a device thereof, and a recording medium on which the method is programmed and recorded.

[0010]

According to a first aspect of the present invention, there is provided an image forming apparatus comprising: a plurality of monochromatic L-shaped test patterns prepared for each color material used in a printing process; Generates and outputs the output monochromatic L
The character patterns are sequentially read, fetched as RGB signals, the relative coordinate position of each single-color L-shaped pattern with respect to the reference L-shaped pattern is measured and compared with a predetermined ideal relative coordinate position. The amount of displacement in the scanning direction and the sub-scanning direction is measured to calculate an adjustment amount so as to minimize the amount of displacement, and the print timing is adjusted based on the calculated amount of adjustment.

According to a second aspect of the present invention, a single-color L-shaped pattern prepared for each color material used in a printing process is generated and output, and the output L-shaped pattern is captured and recorded as an RGB image pattern. Measuring the intersection coordinates of the L-shaped pattern in the printing process color having a complementary color relationship with a reference color for each of the recorded RGB image patterns;
On the basis of the coordinates of the intersection of the black L-shaped pattern, the relative position coordinates of the L-shaped pattern of the printing process color having the complementary color relationship are obtained, and the obtained relative position coordinates are compared with the relative position coordinates which are design values. And calculating an average value and a maximum value of the shift amounts calculated for the one or more L-shaped patterns, and calculating an average value of the shift amounts of the respective color materials used in the printing process. And the maximum value, the displacement amount in the color image is measured by comparing with the standard value, and the adjustment amount is calculated so that the displacement amount is minimized by measuring the displacement amount. The printing timing is adjusted based on the adjustment amount.

[0012] Thus, since the color shift in the color image is inspected by the average value and the maximum value of the shift amounts of the respective color materials used in the printing process, the inspection of the color shift amount more accurately corresponds to human vision. , And automatic adjustment of the print timing based on the deviation amount becomes possible.

According to a third aspect of the present invention, a device to be inspected for printing an image generated by an inspection device and a single-color L-shaped pattern prepared for each color material used in a printing process are arranged adjacent to each other and have regularity. A plurality of inspection devices that are generated and supplied to the inspection device, and an image input device that sequentially reads the single-color L-shaped patterns from an image output printed by the inspection device, converts the monochrome L-shaped patterns into RGB L-shaped patterns, and stores the L-shaped patterns. The output device and the image input / output device cut out an RGB L-shaped pattern for each predetermined unit, measure the intersection coordinate position of each of the L-shaped patterns, and compare the measured intersection coordinate position with a predetermined ideal coordinate position. The color misregistration amount of the image in the main scanning direction and the sub-scanning direction is measured, and the measured misregistration amount is compared with a standard value. Calculating an adjustment amount, it was decided comprising an adjustment device for adjusting the print timing based on the adjustment amount.

The invention described in claim 4 is the third invention.
5. The image misalignment self-adjustment device according to item 1, wherein the adjustment device is configured to generate a plurality of regular-color L-shaped patterns prepared for each color material used in a printing process, and to generate a plurality of images with regularity. Output means for outputting the output image to a printing device; and R, G, B from the image input / output device.
The L-shaped pattern is cut out for each predetermined unit, the intersection coordinate position of each of the L-shaped patterns is measured, and compared with a predetermined ideal coordinate position, so that the main scanning direction and the sub-scanning direction of the printed image are obtained. A position shift amount measuring means for measuring the position shift amount, and comparing the measured position shift amount with a standard value to calculate a position shift adjustment amount in the color image, and adjusting the printing timing based on the adjustment amount. And a timing adjusting means for performing the above.

With the above arrangement, the positions of the vertical line and the horizontal line of the monochromatic L-shaped pattern generated corresponding to the printing process color are detected, and the coordinates of the intersection are calculated and compared with the predetermined ideal coordinate position. By doing so, it is possible to provide an inspection apparatus that can automatically perform color misregistration in the main scanning direction and the sub-scanning direction and that can accurately inspect human vision. Further, by comparing the measured displacement amount with the standard value, the displacement amount adjustment amount in the color image can be calculated, and the printing timing can be automatically adjusted based on the adjustment amount.

According to a fifth aspect of the present invention, an inspection pattern generating means for reading and outputting a single-color L-shaped pattern prepared for each color material used in a printing process, and reading and outputting the output inspection pattern are obtained. RG for L-shaped pattern
Recording means for capturing and recording as an image pattern of B;
Measuring means for measuring the intersection coordinates of the L-shaped pattern in the printing process color having a complementary color relationship with black for each of the recorded RGB image patterns; and the complementary color based on the intersection coordinates of the black L-shaped pattern. Relative position coordinate calculating means for calculating relative position coordinates of the L-shaped pattern of the printing process color having a relationship, and calculating the amount of deviation from the design value by comparing the calculated relative position coordinate with the relative position coordinate which is a design value. Position deviation calculating means, and calculating an average value and a maximum value of the position deviation calculated for the one or more L-shaped patterns;
Logic operation means for calculating an amount of misregistration adjustment in a color image by comparing an average value and a maximum value of misregistration amounts of the respective color materials used in the printing process with a standard value; And a timing adjusting means for adjusting the printing timing based on the above.

With the above arrangement, a monochromatic L-shaped pattern prepared for each color material used in the printing process is read, the read L-shaped pattern is captured and recorded as an RGB image pattern, and the recorded RGB image pattern is recorded. every,
The intersection coordinates of the L-shaped pattern in the reference color and the printing process color having the complementary color relationship are measured, and the relative position coordinates of the L-shaped pattern of the printing process color in the complementary color relationship are measured with reference to the intersection coordinates of the black L-shaped pattern. Is calculated, and the obtained relative position coordinates are compared with the relative position coordinates, which is a design value, to calculate a shift amount with respect to the design value, and the average value and the maximum value of the shift amounts calculated for all the captured L-shaped patterns are calculated. The values are obtained, and the average value and the maximum value of the deviation amounts of the respective color materials used in the printing process are compared with a standard value to inspect the color deviation in the color image. As a result, it is possible to provide an inspection apparatus that can automatically perform color misregistration in the main scanning direction and the sub-scanning direction and that can accurately inspect human vision. Further, by comparing the measured displacement amount with the standard value, the displacement amount adjustment amount in the color image can be calculated, and the printing timing can be automatically adjusted based on the adjustment amount.

According to a sixth aspect of the present invention, a single-color L-shaped pattern prepared for each color material used in a printing process is printed by a device to be inspected, and the single-color L-shaped patterns are sequentially printed from the printed image. The read image is used in an image misalignment self-adjustment device that measures the misregistration amount of the printed image in the main scanning direction and the sub-scanning direction and adjusts the print timing based on the misalignment amount, and is used in the printing process. Reading a single-color L-shaped pattern prepared for each color material to be used; capturing and reading the read L-shaped pattern as an RGB image pattern; and for each of the recorded RGB image patterns,
Measuring the intersection coordinates of the L-shaped pattern in the printing process color having a complementary color relationship with black; and determining, based on the intersection coordinates of the black L-shaped pattern, the L-shaped pattern of the printing process color having the complementary color relationship. Calculating a relative position coordinate; calculating the amount of deviation from the design value by comparing the calculated relative position coordinate with a relative position coordinate that is a design value; Calculating an average value and a maximum value of the shift amount; comparing the average value and the maximum value of the shift amount of each color material used in the printing process with a standard value; and a position shift generated as a result of the comparison. Calculating an adjustment amount so as to minimize the amount, and instructing adjustment of print timing based on the calculated adjustment amount, and recording and recording the adjustment amount. And the.

Thus, starting from the coarse detection of the position of the color pattern including the reference pattern in the main and sub scanning directions, the position of the color pattern including the reference pattern in the main and sub scanning directions is detected with high precision. By extending the position of the pattern line and determining the intersection coordinates as the pattern coordinates, the measurement of the intersection coordinates can be facilitated and the accuracy can be increased. The calculated relative position coordinates are compared with the relative position coordinates, which are design values, to calculate the amount of deviation from the design value, and the average and maximum values of the amounts of deviation calculated for all the captured L-shaped patterns are calculated. Can be provided, and a program for inspecting the color misregistration in the color image by comparing the average value and the maximum value of the misregistration amount of each color material used in the printing process with the standard value can be provided. In a color printing apparatus, printing is performed using toners and inks of four KCMY colors, and colors are synthesized by superimposing CMY colors. Conventionally, when the position of the superimposed colors is shifted in this synthesis process, a color different from the original color is obtained. Combined, the quality of the image was remarkably degraded, especially in line drawings and character portions, but the present invention improves the positional accuracy of the printing position of each color because the amount of misregistration is adjusted and guaranteed. The printing quality is improved.

[0020]

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, reference numeral 1 denotes an inspection device, which takes in an L-shaped pattern printed on an inspection sheet described later and performs measurement and inspection of a positional shift of a color image. Here, a personal computer is used as an inspection device, and a comparison process with a standard value is also performed for the inspection. 2
Is an image input / output board, and the inspection apparatus 1 is a PCI (Pe
(Ripheral Component Interconnect) bus 6 and captures an image captured via the measurement scanner 5 via a dedicated video interface 7. In addition,
When a copying machine is connected as a device to be inspected, a scanner provided in the copying machine can be used in place of the measurement scanner 5.

The general operation of the above configuration is as follows. That is, inspection pattern data is output to the device to be inspected, for example, a printer or a copying machine via the image input / output board 2, and the inspection pattern is read. After this image reading is completed, the position of each color pattern is measured, the amount of deviation from the pattern design value (ideal position) is calculated, and a pass / fail judgment is made by comparing the deviation with a standard value. Details will be described later with reference to a flowchart.

FIG. 2 is a block diagram showing another embodiment of the present invention. Here, a printer is connected in addition to the copying machine as the device 4 to be inspected, and is connected to the pattern generator board 3 via the dedicated video interface 7 and the dedicated printer interface 9, respectively. It should be noted that the measuring scanner 5 for reading an image is
CSI (Small Computer System Bus) or US
It may be connected via a scanner interface such as B (Universal Serial Bus). Details such as the internal configuration of the above-described inspection apparatus 1 and pattern generator board 3 will be described later.

FIG. 3 shows an example of a color image misregistration measurement pattern printed on an inspection sheet used in the present invention. Here, a single-color L-shaped pattern prepared for each of cyan (C), magenta (M), yellow (Y), and black (B), which is a color material (toner / ink) used in the printing process, is represented by one. Four pieces are arranged adjacent to each other and are arranged (printed) continuously on the entire surface of the inspection sheet 10.

The printing area for the inspection sheet 10 is 6 mm inside the paper edge at each of the four corners, and has an L-shape as shown in FIG. 3A. The L-shaped pattern has a line length of 114 dots both vertically and horizontally and a line width. It is assumed that there are two dots, and an L-shaped pattern of another color is arranged at a distance of 12 dots.
That is, an L-shaped pattern, an inverted L-shaped pattern, an L-shaped pattern rotated by 90 degrees, and an inverted L-shaped pattern rotated by 90 degrees are arranged adjacent to each other in one division area. The numbers in the figure are all non-inspection devices 4
Represents the number of dots when the resolution is 400 dpi. FIG. 3 shows an example of a continuous pattern printed on an inspection sheet.
This is shown in (b).

Note that the smaller the size of the L-shaped pattern (the line length, interval, and thickness of each color), the higher the density can be measured. However, the probability of erroneous recognition and erroneous detection increases. Become. Specifically, if the distance between the L-shaped patterns is too wide, there is a possibility that the purpose and the characteristic of detecting the positional deviation at the same position may be different from each other. And the probability of erroneous measurement increases. On the other hand, if the pattern is too large, the density to be measured will be coarse, and if it is too small, the tolerance for pattern displacement will be small, and the probability of erroneous measurement will be high. Furthermore,
If the line width is too thin, the line tends to be faint, and if it is too thick, the measurement error of the line position (center position) tends to increase. Therefore, it is necessary to set an optimal value according to the measurement specifications.

The above pattern can be visually inspected with a loupe, but for visual sensory evaluation, four colors of ink (toner) are superimposed at the same position and it is determined whether or not the line appears colored. The easiest to do. To this end, a cross-shaped pattern is effective for simultaneously viewing both the main and sub-scans. Therefore, here, FIG.
As shown in (d), by arranging the cross-shaped pattern for visual evaluation and the above-described L-shaped pattern for machine inspection alternately in the row or column direction, the measurement pattern can be shared by both.

The above-described pattern is created using commercially available image creation / processing software such as photo retouching. Here, Adobe's Photoshop
op version 5.5 shall be used. In this case, first, a file for creating a pattern in CMY colors for the size of one pattern (240 × 240 dots) is opened. Next, an L-shaped pattern corresponding to each color of KCMY is created for the entire file. The pattern density is 100%. Thus, one single pattern is completed, and a plurality of the single patterns are arranged to complete an inspection pattern. Then, the entire area of the created pattern is selected and registered, and the saving is completed. Next, the size of the inspection pattern to be finally created,
For example, a file is opened in A3 size CMY color. Then, the entire area of the opened file is specified, and the area is filled with the registered pattern.

FIG. 4 is a block diagram showing the internal configuration of the inspection apparatus 1 shown in FIGS. The inspection device 1 has a CPU
11 is a control center, and a main storage device 12 and a hard disk device 13 are commonly connected to a system bus 15. Although not shown, a keyboard / mouse and a display monitor are also connected to the system bus via a dedicated controller. The system bus 15 is connected to the PC via the bus bridge 14.
The image bus is connected to the I bus 3, and the image input / output device 2 (3) including the image memory is connected to the PCI bus 3 as described above.

In the main storage device 12, as an OS (basic software), a Wi-Fi system manufactured by Microsoft Corporation in the United States is used.
Windows 98 are resident, and a pattern generator 122, a printer driver 123, and a scanner driver 124 are allocated and stored as software tools for image input / output. In addition, the above-mentioned Photo
An image creation and processing software 125 such as a shop, and a pattern measurement and evaluation program described later are also allocated and stored. 127 is a work area used by application software such as the image creation, processing program 126, pattern measurement, and evaluation program 126 described above.
Furthermore, a work area having a relatively large capacity is also allocated to the hard disk device 13.

FIG. 5 is a functional block diagram showing an embodiment of the image color misregistration inspection apparatus according to the present invention.
Corresponds to a functional block diagram when the CPU 11 executes the pattern measurement / evaluation program stored in the main storage device 12.

As shown in the figure, the image color misregistration inspection apparatus of the present invention comprises a pattern generation / output unit 111, a color image extraction unit 112, a work memory 113, and a pattern cutout unit 11.
4. Intersection coordinate measurement unit 115, relative position calculation unit 116, deviation amount calculation unit 117, control unit 118, logical operation unit 119,
It comprises a table memory 120 and a timing adjustment unit 121.

The pattern generation / output unit 111 fetches a pattern scanned via the scanner unit of the copying machine (device to be inspected) shown in FIG. 1 or the scanner unit 5 shown in FIG. 2 and supplies it to the color image extraction unit 112. I do. The color image extracting unit 112 extracts a predetermined amount of the captured image for each of the R, G, and B images and discharges the extracted image to the work memory 113. The work memory 113 corresponds to the work area 127 of the main storage device 12 or the work area of the hard disk device 13 shown in FIG. The pattern cutout unit 114 includes R, G, B
Each time, an L-shaped pattern corresponding to one section is cut out from the work memory 113 and supplied to the intersection coordinate measuring unit 115.

The intersection coordinate measuring unit 115 obtains the intersection coordinates of the L-shaped patterns of the colors constituting R, G, and B according to an algorithm described later and supplies the coordinates to the relative position calculating unit 116. The relative position calculator 116 calculates the relative position of the intersection coordinates of the color pattern based on the previously obtained intersection coordinates, and passes the calculated relative position to the displacement amount calculator 117. The shift amount calculating unit 117 compares the relative coordinates obtained by the relative position calculating unit with the relative coordinates defined in advance as ideal values in the table memory 120, calculates a shift amount, and outputs the shift amount to the logical operation unit 119. The control unit 118 controls the order of each operation by the intersection coordinate measurement unit, the relative position calculation unit, the shift amount calculation unit 117, and the logical operation unit 119. The logical operation unit 119 accumulates the deviation amount calculated by the deviation amount calculation unit 117 as the deviation amount of the color pattern, obtains the average value and the maximum value of the deviation amount calculated for the pattern on the entire inspection sheet, and defines in advance. Then, a pass / fail judgment is made by comparing with a standard value recorded in the table memory 120. The timing adjustment unit 121 includes the logical operation unit 1
Further, the position shift adjustment amount in the color image is calculated by 19, and the print timing is adjusted based on the calculated adjustment amount. Details of the processing flow and the like will be described later using a flowchart.

FIGS. 6 and 7 are block diagrams showing the internal configuration of the image input / output device shown in FIGS. 1 and 2, respectively.

FIG. 6 shows the configuration of an image input / output device for connection to a copying machine. The image input / output device 2 includes an image memory 21 in which color image information is developed in a bitmap format, and an image control circuit. 22, a data selector 23 and a PCI bus interface 24. Image input / output device 2
Is connected to the inspection apparatus 1 via a PCI bus 6 and to the copying machine 4 via a dedicated video interface 7, and when outputting data to the copying machine 4, is directly connected via the dedicated video interface In addition, when the image memory 21 is accessed from the inspection apparatus 1, data is input / output while performing bus conversion via the internal local bus 24.

FIG. 7 shows the configuration of an image input / output device for connection to a printer. The image input / output device 3 has an image memory 31 in which color image information is developed in a bitmap format as a core, and an image control circuit. 32, a PCI bus interface 33, a local bus interface 34, and an image data bus interface 35. Image input / output device 3
Are directly connected to the inspection apparatus 1 via the PCI bus 6 and to the image data bus interface 35 connected to the printer connected as the apparatus 4 to be inspected. Therefore, the inspection pattern can be directly output to the printer engine using the pattern generator 122 without the intervention of the printer driver 123 stored in the main storage device 12. The image control circuit 32 performs a rasterizing process for this.

FIG. 8 is a flowchart showing the operation of the image color misregistration inspection apparatus of the present invention, and specifically shows a processing procedure for image color misregistration inspection by the pattern measurement / evaluation program shown in FIG.

Hereinafter, the operation of the embodiment of the present invention shown in FIGS. 1 to 7 will be described in detail with reference to FIG. First, the inspection apparatus 1 generates an inspection pattern by the above-described method, supplies the generated inspection pattern to the copying machine or the printer as the inspection target apparatus 2 via the image input / output apparatus 2 (3), and performs a printing process (step S81). , S82). The printed inspection pattern is taken in and stored again in the inspection apparatus 1 by the scanner unit of the copying machine or the scanner device 5 connected externally (step S83). The printed L-time pattern of each single color is taken in as three color signals of red (R), green (G), and blue (B) by the scanner unit of the copier or the scanner device 5 and input into the image. It is stored in the image memory 21 in the output device 2.

Next, the inspection apparatus 1 first extracts only the R image from the image memory 21 and reads it out to the work area 127 in the inspection apparatus 1 (step S84). From the relationship of complementary colors, the R image can clearly distinguish the black and cyan L-shaped patterns. Next, an image of an area including one set (four L-shaped patterns) of patterns at the upper left corner of the inspection sheet is cut out (step S85), and intersection coordinates (X, Y) of the L-shaped patterns of black and cyan, respectively. ) Is measured (step S86). The measurement algorithm will be described later. Then, the relative position (X, Y) of the cyan pattern intersection coordinates is calculated based on the black pattern intersection coordinates (step S87). Next, the previously obtained relative coordinates are compared with the relative coordinates of the pattern design value, and a deviation amount (X, Y) with respect to the design value (ideal value) is calculated (step S8).
8). Then, the shift amount is determined as the cyan position shift in the pattern 1. The processing from step S85 to step S88 is sequentially performed on all L-shaped patterns printed on the inspection sheet (step S89). Next, an average value and a maximum value of the shift amounts calculated for the L-shaped pattern on the entire inspection sheet by the logical operation unit 119 are obtained (step S1).
00).

Next, only the G image is extracted from the image memory 21 and read out to the work area 127 of the inspection apparatus 1. In the G image, the L-shaped pattern of black and magenta can be clearly distinguished from the complementary color relationship. Steps S85 to S described above
Steps S90 to S93 of the G image corresponding to 88 are sequentially performed on the entire pattern printed on the inspection sheet (step S94), and the logical operation unit 119 calculates the deviation amount calculated for the pattern on the entire inspection sheet. Find the average and maximum. Finally, only the B image is extracted from the image memory 21 and read into the work area 127 of the inspection device 1. In the B image, the L-shaped pattern of black and yellow can be clearly distinguished from the complementary color relationship. Steps S95 to S95 of the B image corresponding to steps S85 to S88 described above
98 are sequentially performed on the entire pattern printed on the inspection sheet (step S99), and the average value and the maximum value of the deviation amounts calculated for the pattern on the entire inspection sheet by the logical operation unit 119 are obtained.

Finally, the logical operation unit 119 uses the above measurement results to determine the average value and the maximum value of the deviation amounts of the C, M, and Y color materials used in the printing process with a predetermined standard value. A pass / fail judgment is made by comparing. If not, an abnormal notification is issued and the process ends (step S104). In the case of a pass, the logical operation unit 119 calculates an adjustment amount based on the calculated positional deviation amount so as to minimize the positional deviation amount (Step S102). Then, the timing adjustment unit 121 is activated, and the print timing is adjusted based on the calculated adjustment amount (step S103).

FIG. 15 shows a specific example of this timing adjustment.
This will be described with reference to FIG. For example, in the embodiment of the present invention shown in FIG. 1, it is assumed that the inspection apparatus 1 first outputs a displacement measurement image in the product internal pattern output mode, and sets the output image on the measurement scanner 5. As a result, the inspection apparatus 1 scans the output image in the product self-inspection mode, fetches the image data into the memory built in the image input / output board 2, and calculates the KCMY relative positional deviation amount according to the above-described algorithm. Then, the adjustment amount is calculated so that the displacement amount at each of the KCMY measurement points is minimized. FIG. 15 shows a specific example thereof.

In the example shown on the left, the position of C (cyan) is shifted to the rear end side by the same amount as a whole with respect to K (black) as the reference color. Therefore, it is necessary to adjust C for the sub resist. Further, in the example shown on the right, a magnification error abnormality in the sub-scanning direction of C is recognized. Here, it is necessary to adjust the sub-registration amount of C so as to minimize the displacement. In any case, the logical operation unit 119 shown in FIG. 5 calculates according to the procedure shown in FIG.
The print timing adjustment circuit of the device to be inspected is driven via 21 to adjust the print timing.

In the above example, the operation is performed in the self-adjustment mode. In the remote adjustment mode, the inspection apparatus obtains, for example, the operation status data of the inspected apparatus, such as the number of copies, via the communication line. The position adjustment amount is calculated from the data at the time of production registered in advance, and is supplied to the device to be inspected again via the communication line to adjust the timing.

FIGS. 9 to 13 are flowcharts cited for explaining the algorithm for the intersection coordinate measurement (steps S86, S91, S96) shown in FIG. 8, and FIG. 15 is a diagram for explaining the operation. It is the operation | movement conceptual diagram quoted.

Hereinafter, the algorithm for measuring the coordinates of the intersection will be described in detail with reference to FIGS. 9 to 13 and FIG.

In the color image misregistration inspection method of the present invention, the inspection apparatus 1 first measures the RGB single-color image file from the color image file 130 in the main storage device 12 to measure the intersection coordinates of the L-shaped pattern. Is read out by a predetermined amount and written in the work area 127 (step S91).
1). Then, a pattern is cut out in units of sections (step S912), and the following measurement operation starts.

The measurement operation is basically performed after coarsely detecting the position of the reference pattern (black) in the main and sub scanning directions for each L-shaped pattern in the section (step S913,
(S914), high-precision detection of the position of the reference pattern in the main and sub scanning directions is performed (steps S915 and S916), and the reference pattern position coordinates are determined (step S917). Further, the position coordinates of the color pattern position coordinates having a complementary color relationship are determined by the same algorithm as the above-described reference pattern.

FIG. 10 is a flowchart showing a procedure for performing coarse detection of the position of the reference (color) pattern in the main scanning direction. FIG. 14 is a conceptual diagram of the operation.

The operation conceptual diagram shown in FIG. 14 will be described below with reference to FIG. The inspection apparatus 1 first calls only a single-color image from the color image file 130 in the main storage device 12 into the work area 127, and cuts out an image area at a coarse detection position where a line is considered to always exist (FIGS. 14a, 14b, and 14c). And step S9131 in FIG. 10). Next, calculation of product-sum data is performed (step S9132 in FIGS. 14D and 10). Here, a graph is shown in which, for example, 10 pixel values that are cut out, for example, vertically arranged in a 10 × 100 area are added, and the sum of the products is arranged in the horizontal direction. In the embodiment of the present invention, since the sum-of-products value is reversed, a black image portion has a peak. Then, the histogram waveform is smoothed by performing a smoothing process (Step S).
9133). Next, the peak position of the waveform is detected, spline processing is performed based on the data of the three pixels before and after including the detected peak value, and the waveform is further shaped (FIGS. 14e and f and steps S9134 and S9135 in FIG. 10).

Then, the peak value is obtained from the obtained spline curve (step S9136), and the higher data value of both end data used for the spline curve calculation is obtained (step S9137). Next, in step S9136,
1 from the bottom between the data obtained based on the processing of S9137
The peak width of the spline waveform is determined using / 3 as a threshold (threshold level), and this is defined as the line width. (Step S9138 in FIG. 14g and FIG. 10) Further, the center position of the width is obtained and is set as a coarse position in the main scanning direction of the reference pattern line (step S9139).

FIG. 11 is a flowchart showing a procedure for roughly detecting the position of the reference (color) pattern in the sub-scanning direction. The inspection apparatus 1 first calls only a single-color image from the color image file 130 in the main storage device 12 into the work area 127, and cuts out an image area at a coarse detection position where a line is considered to exist (step S914).
1). Next, sum-of-products data is calculated (step S91).
42). Here, for example, 10 × 100
The graph shown in the figure is obtained by adding ten pixel values arranged vertically in the area of, and summing the product sum values in the horizontal direction. In the embodiment of the present invention, since the sum-of-products value is reversed, a black image portion has a peak. Then, the waveform is smoothed to shape the waveform (step S9143). Next, the peak position of the waveform is detected, spline processing is performed based on the data of the three pixels before and after including the detected peak value, and the waveform is further shaped (steps S9144 and S9145).

Then, a peak value is obtained from the obtained spline curve (step S9146), and the higher data value of both end data used for the spline curve calculation is obtained (step S9147). Next, in the previous step S9146,
1 from the bottom between the data obtained based on the processing of S9147
The peak width of the spline waveform is determined using / 3 as a threshold (threshold level), and this is defined as the line width. (Step S
9148) Further, the center position of the width is obtained, and is set as the coarse position of the reference pattern line in the sub-scanning direction (step S914).
9).

FIG. 12 is a flowchart showing a procedure for detecting the position of the reference (color) pattern in the main scanning direction with high accuracy. In FIG. 12, the inspection apparatus 1 determines the image area immediately near the pattern intersection based on the sub-scanning direction coarse detection position data of the pattern acquired in the reference pattern sub-scanning direction coarse detection processing (steps S9141 to S9149 in FIG. 11). Is cut out (step S9151). Next, an image data histogram in the main scanning direction is obtained (Step S)
9152) Then, the histogram waveform is smoothed to shape the waveform (step S9153). Next, the peak position of the waveform is detected, spline processing is performed based on the data of the three pixels before and after including the detected peak value, and the waveform is further shaped (steps S9154 and S9155).

Then, a peak value is obtained from the obtained spline curve (step S9156), and the higher data value of both end data used for the spline curve calculation is obtained (step S9157). Next, in step S9156,
1 from the bottom between the data obtained based on the processing of S9157
The peak width of the spline waveform is determined using / 3 as a threshold (threshold level), and this is defined as the line width. (Step S
9138) Further, the center position of the width is obtained and set as the position of the reference pattern line in the main scanning direction (step S9139).

FIG. 13 is a flowchart showing a procedure for performing high-accuracy detection of the position of the reference (color) pattern in the sub-scanning direction. In FIG. 13, the inspection apparatus 1 determines the image area immediately adjacent to the pattern intersection based on the main scanning direction coarse detection position data of the pattern acquired in the reference pattern main scanning direction position coarse detection processing (steps S9131 to S9139 in FIG. 10). Is cut out (step S9161). Next, an image data histogram in the main scanning direction is obtained (Step S)
9162) Then, the histogram waveform is smoothed to shape the waveform (step S9163). Next, the peak position of the waveform is detected, spline processing is performed based on the data of the three pixels before and after including the detected peak value, and the waveform is further shaped (steps S9164 and S9165).

Then, a peak value is obtained from the obtained spline curve (step S9166), and the higher data value of both end data used for the spline curve calculation is obtained (step S9157). Next, the previous step S9166,
1 from the bottom between the data obtained based on the processing of S9167
The peak width of the spline waveform is determined using / 3 as a threshold (threshold level), and this is defined as the line width. (Step S
9168) Further, the center position of the width is obtained, and is set as the position of the reference pattern line in the sub-scanning direction (step S9169).

Then, the pattern line position obtained according to the processing procedures shown in FIGS. 12 and 13 is extended, and the coordinates of the intersection are determined as the reference position pattern coordinates. Further, the color pattern position coordinates are obtained in the same procedure as the above-described reference pattern position measurement, and are determined as the color pattern coordinates.

In the above-described embodiment of the present invention, only the color image misregistration inspection has been exemplified. However, a RGB signal switching means is added to the connection interface of the image input / output device 2 (3), and each color signal is output. The same system construction can be realized even if a monochrome type scanner controller is used by performing the measurement processing. However, in this case, although cost effectiveness can be obtained, three scans are required for coordinate position measurement, and an extra time is required during the scan.

In the above-described embodiment, when a scanner unit of a copying machine connected as the device to be inspected 4 or a printer is connected as the device to be inspected 4, the color to be taken into the inspection device 1 from the scanner device 5 connected externally. The signal is sequentially switched every scan. Then, the image input / output device 2 (3)
First, an R signal is selected, and a pattern of only the R signal is taken into the inspection apparatus 1. In the case of the R signal, since the black and cyan patterns can be clearly discriminated from the relationship between the complementary colors as described above, the intersection coordinates of both patterns are measured. Then, the deviation amount of the cyan pattern is obtained by comparing with the pattern design value which is an ideal value. The above processes are performed on the pattern printed on the entire surface of the inspection sheet.

Next, the G signal and the B signal are sequentially selected by the signal interface, and only the G signal and the B signal are taken into the inspection apparatus 1 respectively. The former can clearly discriminate between the black and magenta patterns, and the latter can clearly discriminate between the black and yellow patterns. Therefore, the intersection coordinates of both patterns are measured. Then, the deviation amount of the cyan pattern is obtained by comparing with the pattern design value which is an ideal value. The above processes are performed on the pattern printed on the entire surface of the inspection sheet. As a result, by performing measurement processing for each color signal, a similar system can be constructed even when a monochrome type scanner is used.

In the above-described embodiment of the present invention, the relative position with respect to black is measured and inspected in order to easily determine the reference pattern within one division pattern, here, the pattern. However, for example, when the order of development is considered, yellow may be used as a reference. At the same time as the inspection, the print quality can be inspected by measuring the absolute position of the pattern on the paper. In this case, a mark is attached to the four corners or more points of the paper surface, and by detecting this mark, the resist (tip, horizontal), magnification error, magnification deviation (vertical, horizontal), parallelism, skew, Inspections such as linearity and paper length are also performed. This makes it possible to provide a printing apparatus with better print quality.

The flowcharts shown in FIGS. 8 to 13 show the operation procedure of the pattern measurement / evaluation program 126. When the program 126 operates, the program is loaded into the main storage device 12 shown in FIG. It is assigned and is always saved in the hard disk drive 13. Alternatively, it is recorded on a recording medium such as an optical disk and distributed, and is installed and used in the system as needed. Further, a form in which the information is supplied via a communication medium such as the Internet is also conceivable.

[0064]

As described above, according to the present invention, a plurality of single-color L-shaped inspection patterns prepared for each color material used in the printing process are arranged adjacent to each other and regularly output, and the output inspection patterns are scanned. It calculates the amount of misalignment in the main scanning direction and the sub-scanning direction by calculating the amount of misalignment by reading in, and calculates the amount of adjustment by comparing with the standard value, and performs self-adjustment so that it is within the standard. Yes,
As a result, it is possible to automatically inspect the color misregistration of each single-color L-shaped pattern in the main scanning direction and the sub-scanning direction and to accurately correspond to human vision. Further, it is possible to automatically adjust the print timing based on the shift amount.

In a color printing apparatus, printing is performed using toners and inks of four colors of KCMY, and colors are synthesized by superimposing CMY colors. Different colors were synthesized, and the quality of the image was significantly degraded, especially in line drawings and character portions. However, the present invention guarantees the amount of misregistration, thereby improving the positional accuracy of the printing position of each color. The printing quality is improved. A cross-shaped pattern is effective for performing a visual inspection in both the main and sub directions. By arranging the visual evaluation pattern and the above-described L-shaped mechanical inspection pattern alternately, the inspection pattern can be shared by both. Therefore, the mechanical inspection and the visual inspection can be performed in both the main and sub scanning directions in parallel, and the degree of color misregistration can be accurately detected, and the amount of color misregistration corresponding to human vision can be detected.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a block diagram showing another embodiment of the present invention.

FIG. 3 is a diagram showing an L-shaped pattern printed on an inspection sheet used in the present invention.

FIG. 4 is a block diagram showing an internal configuration of the inspection device shown in FIGS. 1 and 2;

FIG. 5 is a functional block diagram of a CPU in FIG. 4;

FIG. 6 is a block diagram showing an internal configuration of the image input / output device shown in FIG.

FIG. 7 is a block diagram illustrating an internal configuration of the image input / output device illustrated in FIG. 2;

FIG. 8 is a flowchart showing an operation procedure of the embodiment of the present invention.

FIG. 9 is a flowchart cited for explaining a pattern position measurement algorithm used in the present invention.

FIG. 10 is a flowchart cited for explaining a pattern position measurement algorithm used in the present invention.

FIG. 11 is a flowchart cited for explaining a pattern position measurement algorithm used in the present invention.

FIG. 12 is a flowchart cited for explaining a pattern position measurement algorithm used in the present invention.

FIG. 13 is a flowchart cited for explaining a pattern position measurement algorithm used in the present invention.

FIG. 14 is an operation conceptual diagram cited for explaining the operation of the embodiment of the present invention.

FIG. 15 is a diagram cited for describing the operation of the embodiment of the present invention, and is a diagram illustrating an example of an adjustment example.

[Explanation of symbols]

 Reference Signs List 1 inspection device 2 (3) image input / output device (image input / output board) 4 device to be inspected 5 scanner for measurement 6 PCI bus 7 dedicated video interface 9 dedicated printer interface 10 inspection sheet 21 (31) image memory 22 (32) Image control circuit 23 Data selector 24 (33) PCI bus interface 34 Local bus interface 35 Image data bus interface 111 Pattern generation and output unit 112 Color image extraction unit 113 Work memory 114 Pattern cutout unit 115 Intersection coordinate measurement unit 116 Relative position calculation unit 117 Shift amount calculation unit 118 Control unit 119 Logical operation unit 120 Table memory 121 Timing adjustment unit

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/01 H04N 1/29 G 2H030 G06T 1/00 510 B41J 3/00 B 5B057 H04N 1/29 D 5C074 1/46 H04N 1/46 Z 5C079 9A001 (72) Inventor Fumihiro Nakashige 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (Reference) 2C061 AP04 AQ04 AQ06 AR01 KK13 KK18 2C262 AA03 AA04 AB15 FA03 FA06 FA10 FA13 GA04 GA30 GA32 2C362 BA52 CA22 CA23 CB73 2F065 AA03 AA17 AA20 AA22 AA23 AA56 BB01 BB27 CC02 FF04 FF61 QQ24 QQ25 QQ27 QQ28 QQ29 QQ42 QQ43 RR08 2H027 DE03 EC07 A03 AD03 EC03 A03 EC02 CA08 CA12 CA16 CB01 CB08 CB12 CB16 CE18 CH01 CH11 DA07 DB02 DB06 DB09 5C074 AA10 BB02 BB26 CC26 DD11 DD15 DD22 EE04 FF15 HH02 5C079 HA18 HB01 HB03 KA03 KA15 LA02 LA24 MA10 MA11 NA03 NA06 NA29 PA02 PA03 9A001 EE05 HH34 JJ35 KK42 LL09

Claims (6)

[Claims] 1. A plurality of monochromatic L-shaped inspection patterns prepared for each color material used in a printing process are arranged adjacent to each other, and a plurality of monochromatic L-shaped inspection patterns are generated and output with regularity.
It is captured as a GB signal, and the relative coordinate position of each monochromatic L-shaped pattern with respect to the reference L-shaped pattern is measured and compared with a predetermined ideal relative coordinate position. An image position self-adjustment method, wherein an amount of adjustment is calculated by measuring the amount of positional deviation so as to minimize the amount of positional deviation, and printing timing is adjusted based on the calculated amount of adjustment. 2. A monochromatic L-shaped pattern prepared for each color material used in a printing process is generated and output, the output L-shaped pattern is captured and recorded as an RGB image pattern, and the recorded RGB For each image pattern, measure the coordinates of the intersection of the L-shaped pattern in the reference color and the printing process color in a complementary color relationship to the reference color. Based on the coordinates of the intersection of the black L-shaped pattern, the L of the printing process color in the complementary color relationship is measured. The relative position coordinates of the character pattern are obtained, the calculated relative position coordinates are compared with the relative position coordinates, which is a design value, to calculate a positional deviation amount with respect to the design value, and the relative position coordinates are calculated for the one or more L-shaped patterns The average value and the maximum value of the shift amount are obtained, and the average value and the maximum value of the position shift amount of each color material used in the printing process are compared with a standard value to thereby determine the position in the color image. Measuring the shift amount, calculating the adjustment amount so as to minimize the shift amount by measuring the shift amount, and adjusting the print timing based on the calculated adjustment amount. Image position self-adjustment method. 3. An inspection apparatus for printing an image generated by an inspection apparatus and a single-color L-shaped pattern prepared for each color material used in a printing process are adjacent to each other, and a plurality of patterns are generated with regularity. An inspection device to be supplied to the device; an image input / output device that sequentially reads the single-color L-shaped patterns from an image output printed by the device to be inspected, converts the L-shaped patterns into RGB L-shaped patterns, and stores the converted L-shaped patterns; The L-shaped pattern of RGB is cut out from the output device for each predetermined unit, the coordinate position of the intersection of each of the L-shaped patterns is measured, and compared with a predetermined ideal coordinate position, the main scanning direction of the printed image and A color misregistration amount in the sub-scanning direction is measured, and a misregistration adjustment amount in a color image is calculated by comparing the measured misregistration amount with a standard value. An image position deviation self-adjustment device, comprising: an adjustment device that adjusts a printing timing based on an adjustment amount. 4. An adjusting device, comprising: an image generating means for adjoining a single-color L-shaped pattern prepared for each color material used in a printing process and generating a plurality of patterns with regularity; An output unit for outputting, an R-shaped pattern of R, G, and B is cut out from the image input / output device for each predetermined unit, an intersection coordinate position of each of the L-shaped patterns is measured, and compared with a predetermined ideal coordinate position. By doing so, a displacement amount measuring means for measuring the displacement amount in the main scanning direction and the sub-scanning direction of the printed image, and by comparing the measured displacement amount with a standard value, the color image 4. The apparatus according to claim 3, further comprising: timing adjustment means for calculating a position shift adjustment amount and adjusting printing timing based on the adjustment amount. Adjusting device. 5. An inspection pattern generating means for reading and outputting a single-color L-shaped pattern prepared for each color material used in a printing process, and reading the output inspection pattern and converting the obtained L-shaped pattern into an RGB image. Recording means for capturing and recording as a pattern; measuring means for measuring, for each of the recorded RGB image patterns, intersection coordinates of an L-shaped pattern in the printing process color having a complementary color relationship to black; and the black L-shaped pattern Relative position coordinate calculating means for calculating the relative position coordinates of the L-shaped pattern of the printing process color having the complementary color relationship, based on the coordinates of the intersection, and comparing the obtained relative position coordinates with the relative position coordinates which are design values. A displacement amount calculating means for calculating a displacement amount with respect to a design value, and an average value of the displacement amounts calculated for the one or more L-shaped patterns. A logical operation means for calculating a large value, calculating an amount of misregistration adjustment in a color image by comparing an average value and a maximum value of misregistration amounts of the respective color materials used in the printing process with a standard value, A self-adjustment device for image misalignment, comprising: timing adjustment means for adjusting print timing based on the calculated adjustment amount. 6. A monochromatic L-shaped pattern prepared for each color material used in a printing process is printed by a device to be inspected,
The single-color L-shaped patterns are sequentially read from the printed image to measure the amount of misalignment of the printed image in the main scanning direction and the sub-scanning direction, and adjust the printing timing based on the amount of misalignment. A step of reading a monochromatic L-shaped pattern used for the image position shift self-adjustment device and prepared for each color material used in the printing process; and a step of capturing and recording the read L-shaped pattern as an RGB image pattern Measuring the intersection coordinates of the L-shaped pattern in the printing process color having a complementary color relationship with black for each of the recorded RGB image patterns; and, based on the intersection coordinates of the black L-shaped pattern, Calculating relative position coordinates of an L-shaped pattern of a printing process color having a complementary color relationship; Calculating a shift amount from the design value by comparing the relative position coordinates as a design value; obtaining an average value and a maximum value of the shift amounts calculated for the one or more L-shaped patterns; Comparing the average value and the maximum value of the shift amounts of the respective color materials used with the standard value, and calculating the adjustment amount so that the position shift amount generated as a result of the comparison is minimized; And a step of instructing adjustment of print timing based on the calculated adjustment amount.