JP2021044662A - Image forming apparatus and image forming system - Google Patents

Abstract

To reproduce the color of an image displayed on a display device in an image formed on a recording medium.SOLUTION: In a display unit of a display device 10, the color of a second color patch having the same configuration as a first color patch included in a reference chart 70 is adjusted to match the color of the first color patch. An image forming apparatus reads, with an image reading unit 30, the reference chart and the display unit of the display device 10 on which the second color patch after the color adjustment and a document image are displayed, and generates read image data. The image forming apparatus compares a read value of the second color patch with a read value of the first color patch in the read image data to calculate a color correction parameter, performs color correction on the document image included in the read image data based on the color correction parameter, and forms the document image on a recording medium based on data of the document image after the color correction is performed.SELECTED DRAWING: Figure 11

Description

The present invention relates to an image forming apparatus and an image forming system.

The printing company makes a trial print based on the digital data submitted by the customer, and then makes a final print. At this time, the image to be printed is displayed on the display to check the contents and perform color proofing. The color of the image displayed on the display differs depending on the display, and even if the RGB data used for display is directly converted into YMCK data for printing, the color may not match. For this reason, it is necessary to ask the customer to check the printed matter printed on the test print, and if the result of the test print does not match the color desired by the customer, adjust the color again and repeat the test print and the confirmation of the image by the customer. is there.

In recent years, tablet-type terminals in which a touch panel is formed on a display have become widespread and are used for various purposes. When a user adjusts an image to a favorite color on the display of a tablet terminal, it is desired to obtain the image displayed on the display as a printed matter in the same color.

As a technique for scanning a self-luminous object such as a display of a tablet terminal with a scanner, the scanner is provided with a photodetector that detects the light of the object in addition to the image reader, and the photodetector detects the light of the object. In this case, a scanner device has been proposed in which it is determined that the object is a display (self-luminous object) and the reading lamp is brightened to read the object (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2015-130710

However, due to the characteristics of the scanner, there is a difference in color between the image read by the scanner and the visual result, and when the image read by the scanner is printed as it is, the image is formed with the same color as the display. Was not possible in some cases.

The present invention has been made in view of the above-mentioned problems in the prior art, and an object of the present invention is to reproduce the color of an image displayed on a display device in an image formed on a recording medium.

In order to solve the above problems, the invention according to claim 1 is a second color patch having the same configuration as the first color patch included in the reference chart, and the first color patch is displayed on the display means of the display device. The display means in a state where the second color patch and the original image whose color is adjusted so as to match the color of the above, the reference chart, and the image reading means for generating the scanned image data, and the scanning. The reading value of the second color patch of the image data is compared with the reading value of the first color patch, and the reading value obtained from the display means of the read image data is read from other than the display means. A calculation means for calculating a color correction parameter for color correction to a value corresponding to a value, and a color correction means for performing color correction on the original image included in the scanned image data based on the calculated color correction parameter. An image forming apparatus including an image forming means for forming the original image on a recording medium based on the data of the original image after the color correction is performed.

The invention according to claim 2 is the image forming apparatus according to claim 1, wherein the calculation means corresponds to the second color patch and the first color patch of the read image data for each patch. The difference between the reading values is obtained, and the reading value of the second color patch of the read image data is color-corrected based on the difference for each patch, and the reading value of the first color patch of the read image data. The color correction parameter is calculated so that the difference from the above is minimized.

The invention according to claim 3 is the image forming apparatus according to claim 1 or 2, wherein the image reading means is composed of a flatbed scanner, and the image reading means has a lamp for illuminating an object to be read. The image reading means is provided with a reading control means for controlling the image reading means so as to turn off the lamp when the image reading means reads the display means.

According to a fourth aspect of the present invention, in the image forming apparatus according to the third aspect, the image reading means uses a reading / receiving unit that receives light from the reading object and an output value from the reading / receiving unit. The reading control means has an amplifier for amplifying, and the reading control means detects a peak value corresponding to a white patch displayed on the display means from the read image data, and the peak value is not within a predetermined range. In this case, adjusting the gain of the amplifier and causing the image reading means to read the display means with the adjusted gain is repeated until the peak value falls within the predetermined range.

The invention according to claim 5 is the image forming apparatus according to claim 4, wherein the reading control means reads the reading when the peak value does not fall within the predetermined range in the gain adjustment of the amplifier. The exposure time in the light receiving unit is made longer than the current state, and the image reading means is made to read the display means at the changed exposure time until the peak value is within the predetermined range.

The invention according to claim 6 is an image forming system including a display device having a display means and an image forming device, wherein the display device has the same configuration as the first color patch included in the reference chart. The display control means for displaying the two-color patch on the display means and the color of the second color patch displayed on the display means by the user are matched with the color of the first color patch included in the reference chart. The image forming apparatus includes an operating means for operating and a color adjusting means for adjusting the color of the second color patch displayed on the display means based on the operation from the operating means. An image reading means that reads an image and the display means in a state where the second color patch whose color is adjusted by the color adjusting means is displayed, the reference chart, and generates read image data, and the read image data. The reading value of the second color patch is compared with the reading value of the first color patch, and the reading value obtained from the display means of the read image data is converted into a reading value obtained from other than the display means. A calculation means for calculating a color correction parameter for color correction to a corresponding value, a color correction means for performing color correction on the original image included in the scanned image data based on the calculated color correction parameter, and a color correction means. An image forming means for forming the original image on a recording medium based on the data of the original image after the color correction is performed is provided.

According to the present invention, the colors of the image displayed on the display device can be reproduced in the image formed on the recording medium.

It is a block diagram which shows the functional structure of a display device. It is a figure which shows the example of the reference chart. It is a schematic cross-sectional view which shows the whole structure of an image forming apparatus. It is a block diagram which shows the functional structure of an image forming apparatus. It is a figure which shows the structure of the image reading part. It is a flowchart which shows the color adjustment process executed by a display apparatus. It is a figure which shows the example of the manuscript data. This is an example of a color adjustment screen displayed on a display device and a reference chart. This is an example of a scanning screen displayed on a display device. It is a flowchart which shows the document image formation process executed by an image formation apparatus. It is a figure for demonstrating the reading method of a display apparatus and a reference chart. It is a flowchart which shows the color correction parameter calculation process.

Hereinafter, embodiments of the image forming apparatus and the image forming system according to the present invention will be described with reference to the drawings. The present invention is not limited to the illustrated examples.
The image forming system according to the present embodiment includes a display device 10 (see FIG. 1) and an image forming device 20 (see FIGS. 3 and 4). This image forming system is used by a printing company or the like that forms an image at the request of a customer.

The display device 10 is a tablet-type terminal used when displaying a document image to be printed and performing color proofing. The content of the manuscript image is not particularly limited, and may be an image, a photograph, a material created by a customer, or the like.

The image forming apparatus 20 forms an image on a recording medium using four colors of yellow (Y), magenta (M), cyan (C), and black (K). The image forming apparatus 20 is equipped with an image reading unit 30 (see FIGS. 3 to 5) for a copy function and a scanning function.

FIG. 1 is a block diagram showing a functional configuration of the display device 10.
The display device 10 includes a control unit 11, an operation unit 12, a display unit 13, a communication unit 14, a storage unit 15, and the like, and each unit is connected via a bus 16.

The control unit 11 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), and the like. The CPU of the control unit 11 reads various processing programs stored in the storage unit 15 and expands them in the RAM, and executes various processes according to the expanded programs.

The operation unit 12 generates an operation signal according to the user's operation and outputs it to the control unit 11. The operation unit 12 is composed of a touch panel arranged so as to be superimposed on the screen of the display unit 13, operation keys, and the like. For example, the operation unit 12 is used when instructing adjustment of the color brightness, hue, saturation, etc. of the image displayed on the display unit 13.

The display unit 13 is composed of an LCD (Liquid Crystal Display) or the like, and displays an operation screen or the like according to the instructions of the control unit 11. The display unit 13 displays the original image, the second color patch, and the like. The second color patch has the same configuration as the first color patch included in the reference chart. The first color patch and the second color patch are a group of patches including patches of a plurality of colors. The "same configuration" of the second color patch as the first color patch means that the color of each patch included in the second color patch and the first color patch is the same (the color of the second color patch is changed to the first color patch by color adjustment). It is not necessary for the colors to match exactly in order to match the colors of, but the colors are close to the extent that the colors can be matched by color adjustment.) , It means that the arrangement of each corresponding patch is the same. Further, it is desirable that the sizes of the second color patch and the first color patch are substantially the same.

FIG. 2 shows an example of the reference chart 70. The reference chart 70 is a printed matter in which the first color patch 71 is formed on paper or the like. In the example shown in FIG. 2, 12 patches are included in the first color patch 71. In the drawing, the difference in color is expressed by the difference in the pattern of each patch. It is desirable that each patch contains the basic colors used in the image, such as red, green, blue, yellow, magenta, cyan, and gray gradations.

The communication unit 14 transmits / receives data to / from an external device connected to the communication network.

The storage unit 15 is composed of a storage device such as a non-volatile semiconductor memory or a hard disk, and stores data such as various processing programs executed by the control unit 11, parameters necessary for executing the processing, and processing results.
For example, the storage unit 15 stores data of a manuscript image to be printed (manuscript data) and data for displaying a second color patch.

The control unit 11 causes the display unit 13 to display the original image based on the original data.
The control unit 11 adjusts the color of the original image displayed on the display unit 13 in response to an instruction from the user's operation unit 12 (color proofing).

The control unit 11 causes the display unit 13 to display the second color patch based on the data of the second color patch. That is, the control unit 11 functions as a display control means.
The operation unit 12 accepts an operation by the user for matching the color of the second color patch displayed on the display unit 13 with the color of the first color patch included in the reference chart.
The control unit 11 adjusts the color of the second color patch displayed on the display unit 13 based on the operation from the user's operation unit 12. That is, the control unit 11 functions as a color adjusting means.

FIG. 3 is a schematic cross-sectional view showing the overall configuration of the image forming apparatus 20. FIG. 4 is a block diagram showing a functional configuration of the image forming apparatus 20.
The image forming apparatus 20 includes a control unit 21, an operation unit 22, a display unit 23, a communication unit 24, a storage unit 25, an image reading unit 30, an image processing unit 50, an image forming unit 60, and the like, and each unit is a bus. It is connected via 26.

The control unit 21 includes a CPU, RAM, and the like. The CPU of the control unit 21 reads various processing programs stored in the storage unit 25, expands them in the RAM, and executes various processes according to the expanded programs.

The operation unit 22 generates an operation signal according to the user's operation and outputs it to the control unit 21. The operation unit 22 is composed of a touch panel arranged so as to be superimposed on the screen of the display unit 23, operation keys, and the like.
The display unit 23 is composed of an LCD or the like, and displays an operation screen or the like according to the instructions of the control unit 21.

The communication unit 24 transmits / receives data to / from an external device connected to the communication network.

The storage unit 25 is composed of a storage device such as a non-volatile semiconductor memory or a hard disk, and stores data such as various processing programs executed by the control unit 21, parameters necessary for executing the processing, and processing results.

The image reading unit 30 is composed of a flatbed scanner, reads an object to be read, and generates scanned image data (RGB data). The image reading unit 30 includes a platen glass 31, a lamp 32, a mirror 33, a CCD (Charge Coupled Device) 34, and the like. The lamp 32 is a light source that illuminates the object to be read mounted on the platen glass 31. The mirror 33 guides the light reflected from the object to be read to the CCD 34. The CCD 34 receives the light reflected from the object to be read and guided by the mirror 33, and outputs an electric signal corresponding to each color of red (R), green (G), and blue (B) by photoelectric conversion. That is, the CCD 34 is a reading / receiving unit that receives light from the object to be read.

The configuration of the image reading unit 30 will be described with reference to FIG. The image reading unit 30 includes a lamp 32, a mirror 33, a CCD 34, a control circuit 35, a clock driver 36, an amplifier 37, an A / D converter 38, a slider 39, a motor 40, a motor driver 41, a lamp driving unit 42, and the like.

The control circuit 35 controls each unit of the image reading unit 30 according to the control of the control unit 21.
The clock driver 36 controls the reading timing (exposure time, etc.) of the CCD 34.
The amplifier 37 amplifies the electric signal (output value) output from the CCD 34.
The A / D converter 38 converts the electric signal (analog data) amplified by the amplifier 37 into digital data.
The slider 39 is equipped with a lamp 32 and a mirror 33, and moves in the X direction shown in FIG. 3 when reading an object to be read mounted on the platen glass 31.
The motor 40 is a motor for moving the slider 39.
The motor driver 41 controls the operation (on, off, rotation direction, rotation speed, etc.) of the motor 40.
The lamp driving unit 42 controls lighting / extinguishing of the lamp 32.

The image processing unit 50 performs various image processing such as color correction processing on the image data read by the image reading unit 30. The color correction process is a process of converting the pixel value of each color of the image data so that the color of the image becomes a target color.

The image forming unit 60 is based on the image data (YMCK data) of yellow (Y), magenta (M), cyan (C), and black (K) obtained by processing by the image processing unit 50. An image is formed on a recording medium. The image forming section 60 includes a yellow image forming section 61Y, a magenta image forming section 61M, a cyan image forming section 61C, a black image forming section 61K, an intermediate transfer belt 62, a secondary transfer section 63, a fixing section 64, and the like.

The yellow image forming unit 61Y includes a photoconductor, a charging unit, an exposed unit, a developing unit, and the like. The photoconductor is uniformly charged by the charged portion and then scanned and exposed by the exposed portion based on the yellow image data to form an electrostatic latent image. Yellow toner is attached to the electrostatic latent image on the photoconductor by the developing unit, and a yellow toner image is formed on the photoconductor.
The magenta image forming portion 61M, the cyan image forming portion 61C, and the black image forming portion 61K are also the same as the yellow image forming portion 61Y except that the colors of the formed toner images are different.

A toner image of each color is transferred to the intermediate transfer belt 62 from a photoconductor corresponding to each color of yellow, magenta, cyan, and black. That is, a color toner image in which toner images of each color are superimposed is formed on the intermediate transfer belt 62.
The secondary transfer unit 63 transfers the color toner image on the intermediate transfer belt 62 onto the recording medium.
The fixing unit 64 fixes the color toner image on the recording medium by heating and pressurizing the recording medium on which the color toner image is transferred.

In the image forming apparatus 20, the color measurement values of each patch of the first color patch included in the reference chart are acquired in advance, and when the reference chart is read by the image reading unit 30 and copied, the color is the same as that of the reference chart. The image is adjusted so that it is formed on the recording medium. That is, a parameter for color-converting RGB data obtained by reading a normal reading object such as a reference chart or paper into YMCK data that can be reproduced in the same color as the reading object by the image forming unit 60. Is prepared.
Further, the present invention makes it possible for the image forming unit 60 to reproduce the read image data obtained by reading the display unit 13 of the display device 10 in the same color as the image on the display unit 13.

The control unit 21 controls the image reading unit 30 to read the display unit 13 of the display device 10 in the state where the original image and the color-adjusted second color patch are displayed and the reference chart, and read the scanned image. Generate data.

The control unit 21 controls the image reading unit 30 so that the lamp 32 is turned off when the image reading unit 30 reads the display unit 13 of the display device 10. That is, the control unit 21 functions as a reading control means.

The control unit 21 detects the peak value corresponding to the white patch displayed on the display unit 13 of the display device 10 from the scanned image data. The control unit 21 adjusts the gain of the amplifier 37 when the peak value is not within a predetermined range, and causes the image reading unit 30 to read the display unit 13 of the display device 10 with the adjusted gain. Repeat until the value is within a predetermined range.

When the gain adjustment of the amplifier 37 does not bring the peak value within a predetermined range, the control unit 21 sets the exposure time of the CCD 34 longer than the current state, and sets the display device 10 on the image reading unit 30 with the changed exposure time. The reading of the display unit 13 is repeated until the peak value falls within a predetermined range.

The control unit 21 compares the reading value of the second color patch of the read image data with the reading value of the first color patch, and obtains the reading value obtained from the reading image data display unit 13 from other than the display unit 13. A color correction parameter for color correction to a value corresponding to the obtained reading value is calculated. That is, the control unit 21 functions as a calculation means.
Specifically, the control unit 21 obtains the difference in the reading value for each of the corresponding patches for the second color patch and the first color patch of the read image data, and reads based on the difference for each patch. The color correction parameter is calculated so that the difference between the color-corrected value of the second color patch reading of the image data and the reading value of the first color patch of the read image data is minimized.

The control unit 21 causes the image processing unit 50 to perform color correction on the original image included in the scanned image data based on the calculated color correction parameters. That is, the image processing unit 50 functions as a color correction means.

The control unit 21 controls the image forming unit 60 to form the original image on the recording medium based on the data of the original image after the color correction is performed.

Next, the operation in the image forming system will be described.
FIG. 6 is a flowchart showing a color adjustment process executed by the display device 10.

First, the control unit 11 reads the manuscript data selected by the operation from the user's operation unit 12 from the storage unit 15 and displays the manuscript image on the display unit 13 (step S1).
FIG. 7 shows an example of the manuscript data 80. The user confirms the original image displayed on the display unit 13, and if necessary, makes color adjustments such as lightness, hue, and saturation.

The control unit 11 determines whether or not the user has performed an operation for color adjustment (brightness, hue, saturation, etc.) on the original image displayed on the display unit 13 from the operation unit 12 ( Step S2).

When an operation for color adjustment for the original image is performed (step S2; YES), the control unit 11 adjusts the color to the original image displayed on the display unit 13 based on the operation from the operation unit 12. The result is reflected (step S3). After step S3, the process returns to step S2 and the process is repeated. In this way, color proofing is performed on the original image. It is desirable to have the customer confirm the result of color adjustment for the original image.

In step S2, when the operation for color adjustment for the original image is not performed (step S2; NO), that is, when the color adjustment for the original image is completed, the control unit 11 inputs the data of the second color patch. It is read from the storage unit 15 and the adjustment screen for the second color patch is displayed on the display unit 13 (step S4).

FIG. 8 shows an example of a color adjustment screen 131 displayed on the display unit 13 of the display device 10 and a reference chart 70 to be compared with the color adjustment screen 131. The color adjustment screen 131 includes a color patch display area 131A and a color adjustment operation area 131B.
The second color patch 72 is displayed in the color patch display area 131A. Here, the second color patch 72 includes 12 patches.
The color adjustment operation area 131B includes an adjustment patch selection area 90, an R value display area 91, a G value display area 92, a B value display area 93, an increase button 94 to 96 for increasing each color component, and a decrease of each color component. Includes reduction buttons 97-99 for.

The adjustment patch selection area 90 is an area for selecting a patch to be adjusted from the second color patch 72 displayed in the color patch display area 131A. Specifically, the patch No. of the patch to be adjusted is input to the adjustment patch selection area 90.
The R value, G value, and B value, which are the color components of the patch selected in the adjustment patch selection area 90, are displayed in the R value display area 91, the G value display area 92, and the B value display area 93, respectively. .. After the color adjustment, the adjusted R value, G value, and B value are displayed in the R value display area 91, the G value display area 92, and the B value display area 93.
When the increase buttons 94 to 96 are pressed, the corresponding color component is increased for the patch selected in the adjustment patch selection area 90.
When the decrease buttons 97 to 99 are pressed, the corresponding color component is decreased for the patch selected in the adjustment patch selection area 90.

The control unit 11 determines whether or not the user has performed an operation for color adjustment (brightness, hue, saturation, etc.) on the second color patch displayed on the display unit 13 from the operation unit 12. (Step S5).
For example, the user arranges the reference chart 70 in the vicinity of the color patch display area 131A of the color adjustment screen 131 shown in FIG. 8, and arranges the color of the second color patch 72 of the color patch display area 131A and the reference chart 70. 1 The colors of the color patch 71 are visually compared. The user selects a patch to be adjusted in the adjustment patch selection area 90 for each patch of the second color patch 72 displayed in the color patch display area 131A, and the color of the selected patch is displayed on the reference chart 70. Among the included first color patches 71, each button (increase button 94 to 96, decrease button 97 to 99) of the color adjustment operation area 131B is operated so as to be the same as the color of the patch corresponding to the selected patch. And change the color of the selected patch.

When the operation for color adjustment for the second color patch is performed in step S5 (step S5; YES), the control unit 11 is displayed on the display unit 13 based on the operation from the operation unit 12. The color adjustment result is reflected in the second color patch (step S6). After step S6, the process returns to step S5 and the process is repeated. In this way, all the patches included in the second color patch are color-adjusted to match the colors of the corresponding patches included in the first color patch.

In step S5, when the operation for color adjustment for the second color patch is not performed (step S5; NO), that is, when the color adjustment for the second color patch is completed, the control unit 11 has completed the color adjustment. The original image and the color-adjusted second color patch are displayed on the display unit 13 (step S7).

FIG. 9 shows an example of the scanning screen 132 displayed on the display unit 13 of the display device 10. The scanning screen 132 includes a color patch display area 132A, a white patch display area 132B, and a document image display area 132C.
In the color patch display area 132A, the color-adjusted second color patch 72 (the second color patch 72 whose color is matched with the first color patch 71 of the reference chart 70) is displayed.
A white patch is displayed in the white patch display area 132B. Assuming that the range of RGB data used for the display of the display device 10 is 0 to 100, data of R100, G100, and B100 are used as the white patch, for example.
The color-adjusted original image (the original image color-calibrated in steps S2 and S3) is displayed in the original image display area 132C. Marks (register marks) 132D, 132E, 132F, and 132G for area identification are added to the four corners of the original image.
This completes the color adjustment process.

FIG. 10 is a flowchart showing a document image forming process executed by the image forming apparatus 20. As a premise of this processing, it is assumed that the original image displayed on the display unit 13 of the display device 10 has been color-adjusted to the user's (customer's) favorite color (color proofing). The color of the second color patch displayed on the display unit 13 of the display device 10 is adjusted so as to match the color of the first color patch included in the reference chart.

First, the user sets the display device 10 in which the original image and the second color patch are displayed on the display unit 13 of the display device 10 and the reference chart so as to face the platen glass 31 of the image reading unit 30. (Step S11). On the platen glass 31, the area where the display unit 13 of the display device 10 is placed (for example, the left half of the area where the A3 original is usually placed) and the area where the reference chart is placed are predetermined. Information indicating each area is stored in the storage unit 25. The user arranges the display unit 13 of the display device 10 and the reference chart at predetermined positions.

Next, when the user presses the display reading button by an operation from the operation unit 22 (step S12), the control unit 21 causes the image reading unit 30 to perform a prescan (step S13). Specifically, the control unit 21 controls the image reading unit 30 to read the display screen of the display unit 13 of the display device 10 and the reference chart to generate the scanned image data, and the image reading unit 30 generates the scanned image data. Acquire the scanned image data. At this time, the control unit 21 controls the image reading unit 30 so as to read an image on the platen glass 31 with the lamp 32 turned off in the area where the display unit 13 of the display device 10 is placed.

A method of reading the display device 10 and the reference chart 70 will be described with reference to FIG. Since the display unit 13 of the display device 10 itself emits light, when the image reading unit 30 reads the display screen of the display unit 13, the control unit 21 controls the reading lamp 32 in the range of X1 shown in FIG. Turns off (display reading mode). On the other hand, since the reference chart 70 placed in the area outside the display device 10 is a printed matter (paper or the like), when the image reading unit 30 reads the reference chart 70, the control unit 21 reads in the range of X2 shown in FIG. Lamp 32 is turned on (normal reading mode).

Next, the control unit 21 extracts a region of the white patch displayed on the display unit 13 of the display device 10 from the scanned image data obtained by the prescan. For example, the control unit 21 recognizes the position of the white patch display area 132B (see FIG. 9) with reference to the marks 132D to 132G (see FIG. 9) in the scanned image data.

Next, the control unit 21 detects the peak value having the largest output from the extracted white patch region, and determines whether or not the peak value is within a predetermined range (step S14). Assuming that the range of the scanned image data (RGB data) is 0 to 100, it can be said that the S / N ratio is the best when the scanned value (RGB value) is 100 when the white patch is read. If the value obtained by reading the white patch exceeds 100 or is small (for example, 50), the gain setting of the amplifier 37 is not appropriate. For example, the control unit 21 determines whether or not the peak value is in the range of 90 to 99.

If the peak value is not within the predetermined range (step S14; NO), the control unit 21 determines whether or not the gain value of the amplifier 37 is the maximum (step S15). When the display of the display device 10 is dark, the peak value may not fall within the predetermined range even if the gain of the amplifier 37 is maximized.

If the gain value of the amplifier 37 is not the maximum (step S15; NO), the control unit 21 adjusts the gain value of the amplifier 37 (step S16). Specifically, the control unit 21 controls the control circuit 35, and the control circuit 35 changes the gain value of the amplifier 37. After step S16, the process returns to step S13 and the process is repeated.

In step S15, when the gain value of the amplifier 37 is maximum (step S15; YES), the control unit 21 changes the exposure time of the CCD 34 and the speed of the slider 39 (step S17). Specifically, the control unit 21 controls the control circuit 35, the control circuit 35 controls the clock driver 36, and the exposure time of the CCD 34 is lengthened to increase the output of the CCD 34. In this case, since the scanning time of one line becomes long, it is necessary to slow down the moving speed of the slider 39 according to the exposure time of the CCD 34. Under the control of the control unit 21, the control circuit 35 controls the signal to the motor driver 41 to change the moving speed of the slider 39 to an optimum value. After step S17, the process returns to step S13 and the process is repeated.

In step S14, when the peak value is within the predetermined range (step S14; YES), the control unit 21 causes the image reading unit 30 to perform the main scan (step S18). Specifically, the control unit 21 controls the image reading unit 30 to read the display screen (original image, second color patch) of the display unit 13 of the display device 10 and the reference chart to read the scanned image data. Is generated, and the scanned image data is acquired from the image reading unit 30. At this time, the control unit 21 controls the image reading unit 30 so as to read an image on the platen glass 31 with the lamp 32 turned off in the area where the display unit 13 of the display device 10 is placed.

Next, the control unit 21 performs a color correction parameter calculation process (step S19).
Here, the color correction parameter calculation process will be described with reference to FIG.

The control unit 21 identifies the second color patch displayed on the display unit 13 of the display device 10 based on the position of the mark (register mark) from the scanned image data obtained in the main scan (step S31). For example, the control unit 21 detects marks 132D to 132G (see FIG. 9) from the scanned image data, and recognizes the position of the color patch display area 132A (see FIG. 9) with reference to the detected marks 132D to 132G.
The control unit 21 averages the readings (RGB values) in the patch for each patch of the second color patch (step S32).

Next, the control unit 21 identifies the first color patch included in the reference chart from the scanned image data obtained in the main scan (step S33). For example, the control unit 21 extracts each patch of the first color patch by extracting an edge from a region predetermined as a region on which the reference chart of the scanned image data is placed.
The control unit 21 averages the readings (RGB values) in the patch for each patch of the first color patch (step S34).

Next, the control unit 21 includes the averaged reading value (RGB value) in the reference chart and the second color patch displayed on the display unit 13 of the display device 10 for each patch corresponding to each other. A difference from the first color patch is generated (step S35).

Next, the control unit 21 calculates the color correction parameter from the difference between the reading values for each patch (step S36). For example, the control unit 21 obtains the read values (r, g, b) obtained from the display unit 13 of the display device 10 from the scanned image data from other than the display unit 13, as shown in the following equation (1). _{The color correction parameters a 1 to} a ₉ used in the 3 × 3 color correction matrix for color correction to the values (R, G, B) corresponding to the read values to be obtained are calculated. Here, the control unit 21, reading of each patch of the second color patch (r, g, b), obtained by the color conversion using the color correction parameters _{a 1 ~a 9 (R, G} , and B), as the difference between the readings of each patch of the first color patches is minimized, and calculates the color correction parameters a ₁ ~a _9.

According to the formula (1), the reading value obtained from the display unit 13 of the display device 10 is converted into the reading value (RGB value) when the image on the display unit 13 and the image on the paper having the same color appearance are read. Can be converted.

After the color correction parameter calculation process, returning to FIG. 10, the control unit 21 causes the image processing unit 50 to perform color correction on the original image area included in the scanned image data based on the calculated color correction parameters. Let it be done (step S20). For example, the control unit 21 recognizes the position of the original image display area 132C (see FIG. 9) with reference to the marks 132D to 132G (see FIG. 9) in the scanned image data. The image processing unit 50 performs color correction on the read value (r, g, b) of the original image by the above formula (1).

Next, the control unit 21 controls the image forming unit 60 to form the original image on the recording medium based on the data of the original image after the color correction is performed (step S21). The conventional method is used for color conversion from the original image data (RGB data) after the color correction is performed to the YMCK data used by the image forming unit 60.
This completes the document image forming process.

As described above, according to the present embodiment, after adjusting the color of the second color patch displayed on the display unit 13 of the display device 10 so as to match the color of the first color patch, the display unit 13 By reading the reference chart including the second color patch and the first color patch displayed in, the reading value obtained from the display unit 13 should be color-corrected so that a person can be displayed on the display unit 13. It is possible to acquire the correspondence (color correction parameter) as to whether or not the color can be read as the same color as the color. Therefore, the color of the image displayed on the display device 10 can be reproduced in the image formed on the recording medium by the image forming device 20. Since the original image confirmed by the user (customer) on the display device 10 can be printed in the same color, test printing becomes unnecessary.

Specifically, for the second color patch and the first color patch of the scanned image data, the difference in the reading value is obtained for each patch corresponding to each other, and the second of the scanned image data is obtained based on the difference for each patch. The color correction parameter can be calculated so that the difference between the color-corrected value of the color patch reading value and the reading value of the first color patch of the read image data is minimized.

Further, when the image reading unit 30 reads the display unit 13 of the display device 10, by turning off the lamp 32, it is possible to perform reading suitable for the self-luminous display unit 13.

Further, prior to the main scan, when the peak value corresponding to the white patch is not within a predetermined range in the scanned image data at the time of pre-scan, the gain of the amplifier 37 is adjusted to improve the S / N ratio. This scan can be performed in the state.

If the peak value range is not improved only by adjusting the gain of the amplifier 37, the main scan can be performed with high accuracy by adjusting the exposure time of the CCD 34.

The description in the above embodiment is an example of the image forming apparatus and the image forming system according to the present invention, and is not limited thereto. The detailed configuration and detailed operation of each part constituting each device can be appropriately changed without departing from the spirit of the present invention.

For example, in the above embodiment, when the image reading unit 30 of the image forming apparatus 20 reads the display unit 13 of the display device 10 and the reference chart, the area on which the display unit 13 and the reference chart are placed is predetermined. However, prior to the prescan, the image reading unit 30 reads the image, detects a self-luminous portion (display unit 13) from the scanned image data, and automatically detects the self-luminous portion (display unit 13) of the display device 10. Area and the area of the reference chart may be extracted.

Further, in the above embodiment, the lighting / extinguishing of the lamp 32 is controlled along the moving direction of the lamp 32 and the mirror 33 in the image forming apparatus 20, but the lighting / extinguishing of the lamp 32 is controlled along the direction orthogonal to the moving direction of the lamp 32. The lighting / extinguishing of the lamp 32 may be controlled for each of the divided regions.

In the above description, an example in which a non-volatile memory or a hard disk is used as a computer-readable medium in which a program for executing each process is stored has been disclosed, but the present invention is not limited to this example. As another computer-readable medium, a portable recording medium such as a CD-ROM can be applied. Further, a carrier wave may be applied as a medium for providing program data via a communication line.

10 Display device 11 Control unit 12 Operation unit 13 Display unit 15 Storage unit 20 Image forming device 21 Control unit 22 Operation unit 25 Storage unit 30 Image reading unit 31 Platen glass 32 Lamp 33 Mirror 34 CCD
37 Amplifier 40 Motor 42 Lamp drive unit 50 Image processing unit 60 Image forming unit 70 Reference chart 71 1st color patch 72 2nd color patch 131 Color adjustment screen 132 Scan screen

Claims (6)

A second color patch having the same configuration as the first color patch included in the reference chart, the second color patch whose color is adjusted to match the color of the first color patch on the display means of the display device, and the second color patch. An image reading means that reads the display means in a state where the original image is displayed, the reference chart, and generates scanned image data.
The reading value of the second color patch of the scanned image data is compared with the reading value of the first color patch, and the reading value obtained from the display means of the read image data is obtained from other than the display means. A calculation means for calculating a color correction parameter for color correction to a value corresponding to the read value to be obtained, and
A color correction means for performing color correction on the original image included in the scanned image data based on the calculated color correction parameters, and
An image forming means for forming the original image on a recording medium based on the data of the original image after the color correction is performed, and
An image forming apparatus comprising. The calculation means obtains a difference in reading value for each of the corresponding patches for the second color patch and the first color patch of the read image data, and based on the difference for each patch, the read image. Claim 1 for calculating the color correction parameter so that the difference between the value obtained by color-correcting the reading value of the second color patch of the data and the reading value of the first color patch of the read image data is minimized. The image forming apparatus according to. The image reading means is composed of a flatbed scanner.
The image reading means has a lamp that illuminates the object to be read.
The image forming apparatus according to claim 1 or 2, further comprising a reading control means for controlling the image reading means so that the lamp is turned off when the image reading means reads the display means. The image reading means includes a reading / receiving unit that receives light from the reading object and an amplifier that amplifies an output value from the reading / receiving unit.
The reading control means detects a peak value corresponding to the white patch displayed on the display means from the read image data, and adjusts the gain of the amplifier when the peak value is not within a predetermined range. The image forming apparatus according to claim 3, wherein the image reading means is made to read the display means with the adjusted gain until the peak value is within the predetermined range. When the peak value does not fall within the predetermined range in the gain adjustment of the amplifier, the reading control means makes the exposure time in the reading / receiving unit longer than the current state, and reads the image with the changed exposure time. The image forming apparatus according to claim 4, wherein the means repeats reading the display means until the peak value falls within the predetermined range. An image forming system including a display device having a display means and an image forming device.
The display device is
A display control means for causing the display means to display a second color patch having the same configuration as the first color patch included in the reference chart.
An operating means for the user to operate so as to match the color of the second color patch displayed on the display means with the color of the first color patch included in the reference chart.
A color adjusting means for adjusting the color of the second color patch displayed on the display means based on the operation from the operating means, and a color adjusting means.
With
The image forming apparatus
An image reading means that reads the original image and the display means in which the second color patch whose color has been adjusted by the color adjusting means is displayed, the reference chart, and generates scanned image data.
The reading value of the second color patch of the scanned image data is compared with the reading value of the first color patch, and the reading value obtained from the display means of the read image data is obtained from other than the display means. A calculation means for calculating a color correction parameter for color correction to a value corresponding to the read value to be obtained, and a calculation means for calculating the color correction parameter.
A color correction means for performing color correction on the original image included in the scanned image data based on the calculated color correction parameters, and
An image forming means for forming the original image on a recording medium based on the data of the original image after the color correction is performed, and
An image forming system comprising.

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