JPH0651732A - Display device - Google Patents

Abstract

(57) [Abstract] [Purpose] The purpose of the display device is to automatically perform color matching between the display screen and the corresponding printed matter according to the ambient light. [Configuration] The light reflected from the measurement object through the measurement window (5b) is dispersed by a predetermined filter (9), and each light amount is detected by a sensor (7) to obtain a predetermined tristimulus value representing a color. Colorimeter (30), the tristimulus value of the printed matter (4) obtained by the colorimeter, and a display screen corresponding to the printed matter
A display device having a correction unit (34) for correcting the display color of the display screen so as to match the tristimulus value of (33), and a lighting window (31) is provided in the colorimeter (30). It is provided so that the display color of the display screen is corrected by the tristimulus value obtained by the ambient light taken in from the lighting window.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a display device in DTP (desktop publishing, electronic publishing) or the like having a color matching function of matching an image display color with a color of a printed matter to be input / output.

In recent years, the DTP system has become widespread. This system is configured to display image data read from printed matter, create and edit a new document on the display screen, and output the result to a printer. Full-color display and printing Systems, it is desired that the displayed colors match the printed colors. For this reason, a display device has been developed in which a sensor is provided and the color of the printed matter and the color of the display screen are measured to perform color matching. However, there is a problem that the color of the printed matter and the display color do not match depending on ambient light. is there. Therefore, there is a need for a display device capable of color matching that is not affected by ambient light.

[0003]

2. Description of the Related Art FIG. 8 is a diagram showing an example of a DTP system, and FIG.
[FIG. 6] is a diagram showing a conventional colorimeter. FIG. 8 shows an example of a DTP system including a processing device 1 having a full-color display device, a printer 2 for full-color printing, and an image scanner 3 for collecting color image data from a printed matter. The creator creates a new document by interacting with the display screen of the processing device 1, for example, displaying the printed matter 4 input from the image scanner 3 and mixing a part or all of this screen with the document. After that, it prints out to the printer 2.

The color image data read by the image scanner 3 is usually the International Commission on Illumination C
The tristimulus values (hereinafter, X, Y, Z values) defined by IE are decomposed and passed to the processing device 1, and in the processing device 1,
Image processing is performed with X, Y, Z values, and X, Y, Z values are passed to the printer 2 for printing, but when displaying on a display screen (hereinafter referred to as cathode ray tube CRT), NTSC is used.
(National Television System Committee color syste
m) color stimuli R, G, B (hereinafter, when described as R, G, B values, all represent NTSC color stimulus values) and converted to C
Supply to RT. As is well known, this conversion formula is R = 1.9196X-0.5326Y-0.2883Z G = -0.9843X + 1.9984Y-0.0283Z B = 0.0584X-0.1185Y + 0.8985Z. [Formula (1) below] In the DTP system, since the document is created on the display screen, the color of the display screen and the color of the print result, or the color of the printed matter read from the image scanner 3 and the color of the display screen match. Is desirable. Therefore, as shown in FIG. 8, the colorimeter 5 is applied to the printed matter 4, and then the colorimeter 5 is applied to the corresponding display screen of the printed matter to measure the X, Y, and Z values, respectively, and the X, Y of the display screen is measured. , Z values match the X, Y, Z values of the printed matter, and the R, G, B values obtained by the equation (1) are corrected.

FIG. 9 shows a sectional view of a conventional colorimeter 5. When the surface of the measuring window 5b is applied to the printed matter 4 or the display screen, the printed matter 4 illuminated by the light source 8 passes through the measuring window 5b.
The amount of light reflected from (or the display screen) is detected by the sensor 7 via the filter 9. Here, as shown in FIG. 9, the filter 9 is composed of three filters for separating R, G, and B, and is rotated by a switch (not shown) or the like to pass the R, G, and B filters, respectively. The light amount of the reflected light is detected by the sensor 7, and the light amount is output to the processing device 1 together with the R, G, B identification signals. Then, in the display device of the processing device 1, for each detected light amount, the spectral transmittance of each of the R, G, and B filters, the spectral sensitivity of the sensor 7, the light source defined by CIE, and the light source 8 actually used. And the tristimulus values X, Y,
Converted to Z.

The case 5a of the colorimeter 5 covers the light source 8, the sensor 7, the filter 9, etc. so as to be shielded from the ambient light, except for the measurement window 5b provided on the lower surface of the drawing, and the measurement window 5b. By applying to the printed material 4 or the display surface, the amount of reflected light can be detected without being affected by the illumination light, the reflected light from a portion other than the measurement target, and the like.

When color matching is performed by the colorimeter 5,
For example, X, Y, and Z values of a printed matter having a plurality of color patterns for color matching and X of a display screen corresponding to the printed matter 4 (for example, the printed matter 4 read and displayed by the image scanner 3), The Y, Z values are measured, and the R, G, B values for display are corrected so that the X, Y, Z values on the display screen match the X, Y, Z values of the printed matter 4. Various correction methods have been proposed, but as a simple method, for example, a plurality of points obtained from the printed matter 4 by converting the respective X, Y, and Z values into R, G, and B values by the equation (1) are obtained. R, G, B values (output) of R, G, B values (output) at a plurality of points on the display screen, and a correction curve is calculated from the R, G, B values (input). As a result, the display device corrects the R, G, B values output from the processing device 1 and outputs the corrected values to the CRT.

[0008]

As described above, the conventional color matching between the printed matter 4 and the display screen is performed by measuring the color with the colorimeter 5 having a constant light source 8.
Therefore, even if color matching is performed by the colorimeter 5, the appearance of colors of printed matter and the appearance of colors on a display screen are different under ambient light having different spectral distributions, for example, under an incandescent lamp and a fluorescent lamp. There was a problem that they did not match.

In view of the above problems, it is an object of the present invention to provide a display device capable of performing color matching between a printed matter and a display screen without being affected by ambient light.

[0010]

In the principle diagram of the present invention shown in FIG. 1, reference numeral 30 is a colorimeter, which is provided with a lighting window 31 to take in ambient light and reflects from a measuring object illuminated by using the ambient light as a light source. The amount of light is detected through a predetermined filter. Reference numeral 34 is a correction unit for matching the tristimulus values X, Y, Z of the printed matter 4 obtained by the colorimeter 30 with the tristimulus values X, Y, Z of the display screen 33 corresponding to the printed matter. The display stimulus values R, G, B of the display device are corrected.

[0011]

[Function] A part of the case of the colorimeter 30, for example, a surface facing the measurement window 5b is provided with a daylighting window 31 to take in ambient light. At this time, no light source is provided inside. The ambient light is used as a light source to illuminate the measurement target, and the reflected light is dispersed by a filter to measure the light amount, and the CIE tristimulus values X, Y, and Z values are obtained.

The correction unit 34 detects the X,
The R, G, B values supplied to the display tube are corrected so that the Y, Z values and the X, Y, Z values obtained from the display screen 33 displaying the printed matter 4 match.

As described above, the colorimeter 30 provided with the daylighting window 31
Since the color matching is performed based on the ambient light under the use environment by the color measurement by, it is possible to always match the display color with the color of the printed matter.

When the type of ambient light (illumination light) is specified, the detecting means determines the type of the illumination light, and the correction unit corresponds to the detected illumination light and the display tristimulus values R and G. , B are corrected. For example, a correction table is prepared for each type of illumination light (fluorescent lamp, incandescent lamp, etc.), the correction table corresponding to the detected illumination light is selected, and the display tristimulus values output from the processing apparatus main body. R, G, B are corrected and output.

As described above, since the color of the display screen and the color of the printed matter are matched according to the ambient light, it is possible to easily cope with the change in the ambient light.

[0016]

【Example】

(First Embodiment) FIG. 2 is a sectional view of a colorimeter of the first embodiment, and FIG. 3 is an apparatus configuration diagram of the second embodiment. The first embodiment describes an example of a display device using a colorimeter 30 provided with a daylighting window 31.

FIG. 2 is a sectional view of the colorimeter 30 of the present invention shown in FIG. 1 as viewed from the Z direction. This colorimeter
30 is a light source 8 in the colorimeter 7 of the conventional example shown in FIG.
Except that the lighting window 31 is provided, and other parts have the same structure. The colorimeter 30 may be provided with a function for converting into X, Y, and Z values. When the measurement window 5b of the colorimeter 30 comes into contact with the printed matter 4 and the display screen 33, only ambient light (illumination light) is taken inside the colorimeter 30 to illuminate these measurement targets, and the resulting reflected light is Similarly to the conventional example, the light is input to the sensor 7 via the filter 9, and the light amount in each filter is detected and input to the display device for correction.

FIG. 3 is a block diagram of the inside of the display device when the colorimeter 30 is used. Where 10
Is a correction circuit for R, R
Spectral transmittance of G and B filters, spectral sensitivity of sensor,
The difference between the light source defined by CIE and the light source 8 actually used is corrected and converted into tristimulus values X, Y, Z (X, Y, Z values). 13 is a processor, these converted X,
The Y and Z values are stored in the memory 15. 14 is a correction unit, which is a memory
Correction tables R-19, G-20, B based on the X, Y, Z values of the printed matter 4 stored in 15 and the X, Y, Z values of the display screen.
-21 is created. 15 is a memory, which is the measured X, Y, Z
The value is stored. Numerals 16 to 18 are 8-bit address bus switches, which are switched to the processor 13 side during correction and to the processing device main body side during operation. Reference numeral 19 is a correction table R, 20 is a correction table G, and 21 is a correction table B. In the present embodiment, the 8-bit R, G, B values (Ri, Gi, Bi shown in the figure) output from the processor main body are respectively addressed. 8-bit R, G, B (illustrated Ro, Go,
(Bo) is stored. Reference numerals 22 to 24 are switches for switching the data bus, and correction data is output from the correction unit 14 during correction and stored in each correction table. 25 is a display controller Disp Cont, which is corrected R, G, B (R
o, Go, Bo) is output and displayed on a CRT (not shown).

In the above configuration, the correction table R-19
, G-20, B-21 will be described as an example. First, at the time of initial setting such as when the power is turned on, the correction unit 14 switches the switching units 16 to 18 and the bus switching units 22 to 24 to the processor 13 side to correct the correction tables R-19 and G-20.
, Set the initial value to B-21. This initial value is set so that the R, G, B inputs from the processor body are output as they are. For example, the n address represented by 8 bits.
A value n represented by 8 bits is stored in (n = 0 to 255). This gives the correction curve M as shown in the correction table R-19 of FIG.

At the time of display, the switches 16 to 18 and the switch 22
24 are switched to the processing device side and the display controller 25 side, respectively, and the correction tables R-19, G are set using Ri, Gi, Bi output from the processing device main body as addresses.
-20 and B-21 are referenced and Ro, Go and Bo are output. In this case, since the initial value is set, uncorrected R,
G and B values are output and displayed.

When performing the correction, first, the operator causes the image scanner to read the printed matter 4 (here, it is composed of a plurality of patterns for correction having a non-patterned color), and simultaneously reads the read image data. indicate. Note that image data collected in advance from the printed matter 4 may be stored in a memory and displayed according to a correction instruction.

Next, the colorimeter 30 is applied to one pattern of the printed matter 4 under the same ambient light as the display screen, and the switch 26 is operated to rotate the filter 9. As a result, the respective amounts of light separated into R, G, and B are detected and are input to the display device together with the trigger signal in a distinguishable manner. Then, the input signal is converted into X, Y, and Z values by the correction circuit 10 and stored in the memory 15 by the processor 13.

Next, the operator applies the colorimeter 30 to the display screen corresponding to the pattern measured on the printed matter 4. As a result, the X, Y, Z values of the display screen are stored in the memory 15 by the same operation and process as when the colorimeter 30 is applied to the printed matter 4.
Stored in. Then, such an operation is performed for a plurality of patterns.

When the measurement completion is instructed, the correction section 14 converts the respective X, Y and Z values into the display tristimulus values R, G and B values, and as shown in the correction table R-19 in FIG. A correction curve N is created in 256 units using a plurality of R values obtained on the printed matter 4 and R values on the display screen respectively corresponding to the R values. Then, the switch 16 and the switch 22 are switched to the processor 13 side, and the R value (0 to 255, the value on the horizontal axis of the correction curve) on the display screen side is used as an address in each area to set the R value on the printed matter 4 side ( The value of the vertical axis of the correction curve) is stored.
Then, such processing is performed by the switching devices 17 and 18 and the switching device.
Switch between 23 and 24 and perform for G and B.

By the above processing, the correction tables R-19, G-20, B-21 for making the X, Y, Z values of the display screen approximately match the X, Y, Z values obtained from the printed matter 4 are prepared. It was done. During operation, the switching devices 16 to 18 are switched to the processing device main body side, the switching devices 22 to 24 are switched to the display controller 25 side, and Ri, G output from the main body device is output.
Conversion table with i and Bi as addresses R-19, G-20, B
-21 is referred to and corrected Ro, Go, and Bo are output to the display controller 25 and displayed.

As described above, the colorimeter 30 provided with the daylighting window 31
As a result, a display screen color-matched with the printed matter 4 under ambient light (under use environment) can be obtained. (Second Embodiment) In the second embodiment, the display device is provided with a detecting means for discriminating the type of ambient light (illumination light), and the display color is corrected in accordance with the detected ambient light. An example of correcting the display tristimulus values R, G, and B by the corresponding correction table will be shown.

FIG. 4 is a schematic configuration diagram of the second embodiment, FIG. 5 is an external view of a display device of the second embodiment, FIG. 6 is a detailed configuration diagram of the second embodiment, and FIG. It is a figure showing the example of a determination method. FIG. 4 shows a principle diagram of the second embodiment.
A detection unit 41 for detecting the type of the illumination light source 6 is provided on the substantially same surface as the display surface of the RT 46 and close to the display surface.
The type of ambient light is determined by the correction table 44 or 45.
This shows that (when there are two types of light sources in this case) is selected by the selector 43 and correction is performed.

Hereinafter, a case where a fluorescent lamp or an incandescent lamp is detected as the detecting means 41 will be described. Fig. 7 (a) shows the spectral distribution characteristics of a fluorescent lamp, and Fig. 7 (b) shows the spectral distribution characteristics of an incandescent lamp. For fluorescent lamps, a spike-shaped spectrum near 450 nm (peak value is B) Therefore, the filter a having the maximum transmittance at this wavelength is used, and the filter b transmitting the peak value A near 650 nm is used. As shown in FIG. 7, the difference AB between the two light amounts obtained from the fluorescent lamp through the filters a and b is compared with the difference C-D between the two light amounts obtained from the incandescent lamp through the filters a and b. Since the difference is very small, a predetermined threshold value is set so that the differences A-B and C-D can be discriminated.

FIG. 5 shows an example of a device configuration in which ambient light is discriminated using this principle. In FIG. 5, 40a and 40b are filters a and b, 41a and 41b are sensors, 47a and 47b are analog-to-digital converters ADC, 4
8 and 49 are comparators, 44-R is R value correction table for fluorescent lamps, 4
5-R is a correction table for incandescent lamps of R value, 44-G is a correction table for fluorescent lamps of G value, 45-G is a correction table for incandescent lamps of G value, 44-B is correction table for fluorescent lamps of B value Table 45-B is a correction table for B value incandescent lamps, and 43-R, 43-G and 43-B are selectors.

The correction table 44-R for fluorescent lamps and the correction table 45-R for incandescent lamps have the same structure as the correction table R-19 shown in the first embodiment, and are read-only memories. Comprised of ROM, correction data of the result (for example, the value obtained by the first embodiment) of the printed matter 4 and the display screen that are color-matched under a fluorescent lamp and an incandescent lamp are stored in advance. . Correction table for fluorescent lamps 44-G, 44-
B and incandescent lamp correction tables 45-G and 45-B are also created in the same manner. Then, the outputs Ro, Go, Bo corrected by using R, G, B (Ri, Gi, Bi) output from the processor body as an address are selected by the selectors 43-R, 43-G, 43-B. Output from the correction table on the side (for fluorescent lamps or incandescent lamps).

The light detected by the sensor 41a and the sensor 41b through the filter a and the filter b is converted into an electric quantity, digitally converted by the ADC 47a and ADC 47b, and compared by the comparator 48. The comparator 48 outputs the difference between these two inputs, and this difference output is compared with a threshold value by the comparator 49. If the difference output is smaller than the threshold value, for example, "1" is output and the selector 43-R,
43-G, 43-B input correction table for fluorescent lamps 44-R, 44
-G, 44-B are selected. If the comparison result of the comparator 49 indicates that the difference output is the threshold value or more, "0" is output,
The incandescent lamp correction tables 45-R, 45-G, and 45-B are selected by the selectors 43-R, 43-G, and 43-B.

As described above, it is possible to determine whether the ambient light is a fluorescent lamp or an incandescent lamp and switch to the corresponding correction table, and it is possible to easily perform color matching. It should be noted that although two types of discrimination examples of a fluorescent lamp and an incandescent lamp are used here, it is not limited to these light sources, and needless to say, three or more types of illumination light sources can be targeted.

[0033]

As described above, the present invention provides a display device adapted to perform color matching between a printed material and a corresponding display screen according to ambient light. The effect that is automatically performed is extremely large.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a sectional view of a colorimeter according to an embodiment.

FIG. 3 is a device configuration diagram of a first embodiment.

FIG. 4 is a schematic configuration diagram of a second embodiment.

FIG. 5 is an external view of a display device according to a second embodiment.

FIG. 6 is a detailed configuration diagram of the second embodiment.

FIG. 7 is a diagram illustrating an example of a method for determining ambient light.

FIG. 8 is a diagram showing an example of a DTP system.

FIG. 9 is a diagram showing a conventional colorimeter.

[Explanation of symbols]

1 Processor 2 Printer 3 Image sensor 4 Printed matter 5 Colorimeter 5a Case 5b Measurement window 6 Illumination light source 7 Sensor 8 Light source 9 Filter 10 to 12 Correction circuit 13 Processor 14 Correction unit 15 Memory 16 to 18 Switch 19 Correction table R 20 Correction Table G 21 Correction table B 22 to 24 Switching device 25 Display controller Disp Cont 26 Switch 30 Colorimeter 31 Lighting window 33 Display screen 34 Correction unit 40a, 40b Filter 41 Detection means 41a, 41b Sensor 42 Discrimination unit 43-R, 43- G, 44-B selector 44, 45 Correction table 46 CRT 47a, 47b A
DC 48, 49 Comparator 44-R, 44-G, 44-B Correction table for fluorescent lamps 45-R, 45-G, 45-B Correction table for incandescent lamps

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuhiko Sato 1015 Kamiodanaka, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited (72) Inventor, Hiroshi Oshio 1015, Uedotachu, Nakahara-ku, Kawasaki City, Kanagawa Prefecture, Fujitsu Limited

Claims (2)

[Claims] 1. A sensor (7) for separating light reflected from a measurement object through a measurement window (5b) by a predetermined filter (9).
A colorimeter (30) that obtains a predetermined tristimulus value representing each color by detecting the respective light quantities by, and a display screen corresponding to the tristimulus value of the printed matter (4) and the printed matter obtained by the colorimeter, respectively. A display device having a correction unit (34) for correcting the display color of the display screen so as to match the tristimulus value of (33), wherein a lighting window (31) is provided in the colorimeter (30). Provided, by the tristimulus value obtained as a light source ambient light taken from the daylighting window,
A display device which corrects a display color of the display screen. 2. A display device for converting a standard tristimulus value representing a color into a display tristimulus value for display, and detecting means for detecting the type of illumination light, and the standard tristimulus of the printed matter under the illumination light. A correction unit that corrects the display tristimulus value so that the stimulation value and the standard tristimulus value under the illumination light of the display screen that displays the image of the printed matter are provided, and is calculated from the standard tristimulus value. A display device, wherein the display tristimulus value is corrected according to the illumination light detected by the detection means, and the color of the display screen under the illumination light is matched with the corresponding input / output target printed matter.