JP2003135399A - Color vision-examining method, color vision-examining device, and color identifying capability-investigating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a color vision-examining method and a device to be used for this color vision examination, by which the reliability for an examination result is high while sufficiently ensuring the privacy of a person to be examined, and the degree of a color vision abnormality can be quantitatively known. SOLUTION: On a color display of a computer display, two colors of the same brightness, which exist on the color confusion line for a dichromatism are displayed. A color vision capability is judged by whether these two colors can be identified or not. The displayed two colors are additive mixing colors which are controlled by the computer, and one of them may be an achromatic color. The data in details is selected by a binary searching method. Also, as a practical utilization, a circle having a slightly larger diameter than the longer diameter of an oval of MacAdam which is estimated in the vicinity of an objective color for the measurement on a chromaticity diagram is assumed, and crossing points of a plurality of diameters passing the location of the objective color for the measurement and the circle are determined. Thus, the judgement for the color vision capability in the same manner is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color vision inspection method.

[0002]

2. Description of the Related Art Since color vision is unique to each individual, there are individual differences, and it is extremely difficult to know how other people perceive it, and it is considered that it cannot be quantified. . The most extreme example of individual differences in color vision is an event called color blindness, and in the most extreme case, all colors cannot be distinguished.

As a method for inspecting color vision abnormality, the Ishihara color vision inspection table in which patterns such as numbers are printed by color dots is 193.
It was recommended by the 14th International Ophthalmology Society in 3 years and has since been used as the only method. However, in this inspection method, since the printed matter is viewed with reflected light, it is difficult to secure lighting conditions in addition to the problem of discoloration of the printing ink and discoloration due to weathering of the printing paper. Therefore, the reliability of the inspection result is not always high. . In addition, since the inspection checks whether or not the characters can be read from the inspection table, even if qualitative determination is possible, how difficult it is to read, in other words, how much the color blindness is. It cannot be known quantitatively.

Not only that, but a bigger problem of the Ishihara color vision test is that the inspector's privacy is uncertain because the inspector and the inspector face each other. As a result, there arises a problem of human rights violations such as employment discrimination due to color difference.

Further, a strict color vision test is performed by a color matching test using monochromatic light, but this test requires not only a large scale of equipment but also a quantitative test is very difficult.

[0006]

SUMMARY OF THE INVENTION The present invention aims to solve the problems of these conventional color vision inspection methods, and while ensuring sufficient privacy of the person to be inspected, the inspection results are highly reliable and quantitative. (EN) Provided are a color vision test method and a device used for this color vision test, by which the degree of color vision abnormality can be known.

In the present application, color matching tests are performed utilizing computer displays having controlled emission colors. This color matching test is conducted in an environment where only the subject uses a computer, so privacy is ensured. Also,
Since the emission color is controlled, not only is the inspection result sufficiently reliable, but it is also possible to obtain a quantitative inspection result by the binary search method, and it is possible to eliminate errors from the inspection result by the inconsistency inspection. become.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. First, a method of expressing colors will be described with reference to FIG. There is also a method of specifying the color expression with a standard number as specified in JIS, for example, but it is not possible to glance at the entire color with this method, so in practice, the International Commission on Illumination (CIE: Commission) was adopted in 1931. Internationale de
The "CIE1931 chromaticity diagram (hereinafter simply" chromaticity diagram ")" based on the "XYZ color system" defined by L'Eclairage) is generally adopted.

FIG. 1 shows a schematic diagram of a "chromaticity diagram". In this figure, chromaticity (hue, saturation) is represented on the xy axis, and lightness is represented on the Y axis (not shown). The shape is similar to a color cube. All colors existing in nature can be represented by coordinate values in a chromaticity diagram, and the dominant wavelength component and saturation of that color can be read from the chromaticity diagram.

In the chromaticity diagram, the human visible range has a horseshoe shape 1 as shown in the figure. The upper part is green (G), the lower left part is blue (B), and the lower right part is red (R). And
The center of the horseshoe is white (W), and the outside is invisible black. In this figure, horseshoe 1
The number listed along with is the wavelength of that color in nm. In addition, in FIG. 1, 3 represented as “CRT”
Square 2 is the range of color expression by CRT display,
The triangle 3 expressed as "TFT" is the range of color expression by the TFT liquid crystal display.

Next, the color blindness will be described with reference to FIG. Most people require three colors (red, blue, yellow or R, G, B) to express a color, and such color vision is called a three-color type color vision. However, there is a color vision that does not require three colors to express colors, and such a color vision is called color blindness. A color vision that can be represented by only two colors is called a two-color type, and a color vision that can be represented by only one color is called a one-color type.

A two-color type color vision associated with the chromaticity diagram is shown in FIG. Color blindness in which colors arranged on a straight line drawn from the convergence point P shown in FIG. 2 (a) cannot be discriminated is called first-class two-color color blindness (P). Color blindness in which colors arranged on a straight line drawn from the convergence point D shown in FIG. 2B cannot be identified is called type II two-color color blindness (D). Color blindness in which colors arranged on a straight line drawn from the convergence point T shown in FIG. 2 (c) cannot be identified is called a type III two-color color blindness (T). Further, even in the case of three-color type vision, color vision in which the ratio of three colors is significantly different from normal is called abnormal three-color type vision, and such color vision is called color blindness.

These convergence points P, D and T are called confusion color centers, and P: x = 0.747, y = 0.253, z = 0.000 D: x = 1.080, y = It has been confirmed that -0.080, z = 0.000 T: x = 0.175, y = 0.004, z = 0.821.

According to the invention of the present application, the colors existing on these straight lines called confusion color lines and achromatic colors are displayed on a display by a computer, and the subject himself / herself judges whether or not chromatic colors are displayed. Automatically determines the color blindness. The colors on the computer are R, G, and B colors, each of which has a gradation of 8 bits (256) and a total of 24 bits (1
6,777,216). Note that some graphics computers represent R, G, and B three colors with 10-bit (1024) gradations and a total of 30-bit (1,073,741,824) colors. The relationship between the color represented on the computer and the chromaticity diagram is as follows:
2-1 "is uniquely defined, and the color on the chromaticity diagram is displayed by the computer based on this relationship.

A color vision test method and a color vision test apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 3 shows the case of inspecting the abnormality of the first-kind two-color type color vision (P) related to the confusion color center P, and the confusion color center P and the white center point C on the chromaticity diagram.
Draw a confusion color straight line P-C that passes through, and of the two points where the confusion color straight line P-C intersects the triangle 2, the point farther from the center P of confusion color (green) is P1, and the closer point (red) is P1 '.

Chromatic color (green) corresponding to these points P1
Are combined on a computer, and chromatic colors and achromatic colors are displayed as rectangles 5 and 6 on the CRT display 4 side by side with achromatic colors (gray) having the same brightness as shown in FIG. One of the colors displayed in the rectangles 5 and 6 is always an achromatic color, and the rectangles 5 and 6 may be displayed in an achromatic color. In the example of FIG. 4, the rectangle 5 has a chromatic color and the rectangle 6 has an achromatic color, but naturally the reverse color arrangement is also possible. A black line 7 is arranged at the boundary between the two rectangles so that the colors of the rectangle 5 and the color of the rectangle 6 cannot be directly compared.

The subject compares the color of the rectangle 5 and the color of the rectangle 6 displayed on the CRT display 4, and when it judges that the colors are different, clicks the left button of the computer. The means for inputting the judgment result to the computer is not limited to the left button of the mouse, and it is possible to use any suitable input means such as an appropriate key on the keyboard or a dedicated switch, but the privacy of the subject. In order to preserve the security, the operation is hidden by operating the mouse button.

When the operation is performed, the computer recognizes that the subject judges that the color of the rectangle 5 and the color of the rectangle 6 are different, and the operation is not performed within a predetermined time (for example, 2 seconds). The computer recognizes that the subject has determined that the color of rectangle 5 and the color of rectangle 6 are not different. The display time of 2 seconds is not enough for the examinee to think, and is a time that must be intuitively judged.

When the subject operates, the computer determines that the subject has recognized that one is chromatic. If the subject does not perform any operation, the computer determines that the subject has recognized that only gray, which is an achromatic color, has been displayed, or has not recognized that the chromatic color has been displayed.

If the subject's judgment is correct, a more detailed examination is performed by a binary search (dichotomizing search). (See "Iwanami Information Science Dictionary" for "binary search".) The binary search will be described with reference to FIG. In this explanation, there is no mistake in the operation of the subject,
The explanation will be given assuming that the operation corresponding to one's own judgment is correctly performed. In this figure, C and P1 are points C and P1 existing on the confusion color straight line CP shown in FIG.
The points described as 1, 1/2, 1/4, etc. are confusion color straight lines C- when the point C is 0 and the point P1 is 1.
This is a point existing on P.

When the subject judges that the colors of the points P1 and C are not different, it is not necessary to perform further inspection between the points P1 and C. When the subject determines that the colors of P1 and C are different, the same test is performed on the point P2 located in the middle of the points C-P1.

When the subject judges that the color of the point P2 and the color of the point C are different, the same inspection is performed on the point P3 located in the middle of the points P2-C, and thereafter the same inspection is performed in detail. . When the subject judges that the color of the point P2 and the color of the point C are not different, it is not necessary to perform further inspection between the points P2 and C. Instead, a similar inspection is performed on the point P6 located in the middle of the points P1-P2.

By carrying out such an inspection, it is finally determined up to which point the color can be judged to be different from the point C. With respect to the accuracy, it is possible to make a judgment up to a point of 2-n by n inspections. Similarly, the same convergence point P
A similar test is performed on the point P1 ′ on the first-kind two-color type color vision (P) with respect to the second-type two-color type color vision (D) regarding the confusion color center D and the third kind 2 regarding the confusion color center T. Similar tests are performed on the color type color vision (T).

The inspections of the first-type two-color type color vision (P), the second-type two-color type color vision (D) and the third-type two-color type color vision (T) are not performed in order, but are appropriately mixed. Is done.

If these inspections are performed without error, the minimum required number of inspections is (n
+1) × 2 (direction) × 3 (center of confusion color) times. Therefore, as shown in FIG. 5, the inspection result of [n = 4], that is, the accuracy of 1/16 can be obtained by the inspection of (4 + 1) × 2 × 3 = 30 times.

The result thus obtained is quantitative, and the state of color vision can be visually expressed by entering the result in the chromaticity diagram. Further, the contents of the abnormal three-color type color vision can be specifically expressed by writing on the chromaticity diagram.

However, not all the operations of the subject are correct. Some of the subject's operations are simple mistakes,
There is a possibility that the judgment content of the subject does not match the judgment content of the computer due to operation delay, oversight, or false operation. When such an erroneous operation is performed, a contradiction occurs in the operation content.

For example, if the subject operates that P5 can be discriminated and does not perform the discrimination that P3 is discriminated, this operation is inconsistent.
In such a case, the whole inspection for P1, P2, P3, P4 and P5 is redone and performed again. This method is called a contradiction inspection. Although the number of inspections is increased by adopting this method, the reliability of the inspection result is significantly improved.

[Application Example of the Present Invention] An application example of the present invention will be described with reference to FIG. What is indicated by M in FIG. 6 is how far apart the colors appear to be different from each other at 25 points in the chromaticity diagram, which is called “MacAdam's ellipse”. This ellipse is an exact ellipse and therefore has a major axis and a minor axis. It should be noted that this ellipse is actually a smaller one, and is shown ten times enlarged for convenience of display.

Although humans perceive these colors outside the ellipse to be different, the color discrimination threshold for discriminating whether they are the same color or different colors has a spread approximately three times as large as this ellipse. ing. In other words, if the colors existing within three times the range of each ellipse are used, it is recognized that the same color is used without using the exact same color.

As seen in MacAdam's elliptical shape, the color discrimination threshold does not exist only on the confusion color line but has an elliptical spread, in other words, spreads on a straight line orthogonal to the confusion color line. have. Therefore, similar to the inspection on the confusion color line, a more accurate inspection result can be obtained by performing the same inspection for the color existing on the straight line orthogonal to the confusion color line at the center point C.

In order to perform this inspection, the operation of the device needs to be restricted. Therefore, γ correction for correcting the linearity of the display device and brightness adjustment are performed before the inspection is started.

In the above embodiment, the case where the CRT is used has been described. The reason is that at the present stage, only the CRT is standardized for the emission color, and other display devices LCD, P.
LD, LED and EL are not standardized. However, it goes without saying that these display devices and other display devices can also be used in the present invention if the emission color is standardized. Further, when a precise inspection result is not required, it is possible to use a non-standardized display device.

[Application Example of MacAdam's Ellipse] As described above, humans recognize colors existing within the color discrimination threshold that is three times as large as the range of MacAdam's ellipse. Knowing three times the range of MacAdam's ellipse eases the requirements for colors used in the industrial and expressive fields. However, as shown in FIG.
There are only 25 "ellipses of dams", but as a matter of course, the number exists for infinite colors existing on the chromaticity diagram, that is, an infinite number.

Therefore, it is difficult to find the necessary color discrimination threshold for a certain color and use the result in the industrial or expression field. Conventionally, the color discrimination threshold is obtained by trial and error, which is extremely inefficient. Further, the color discrimination threshold obtained in this way is only qualitative and not quantitative, so the results cannot be diverted and must be calculated each time.

The method of the present invention can be used to determine this color discrimination threshold and is briefly described below. O for displaying the central color O on the display
The computer data of 24 bits or 30 bits corresponding to is determined. Computer data of points Q1 to Q16 at equal intervals (16 in the figure) on a circle Q centered on O is obtained. In this case, the diameter of the circle Q is slightly larger than the expected major axis of the "MacAdam's ellipse". Each diameter is treated as a virtual confusion color line, and a range E1 ~
Find E16. These ranges are elliptic (El
lipse).

The binary search applied in the use example of FIG. 7 will be described with reference to FIG. In this explanation, it is assumed that there is no error in the operation of the subject and that the operation corresponding to his / her own judgment is correctly performed. In this figure, O and Q are points O and Q1, ... Present on the virtual confusion color line on the arbitrary diameter shown in FIG. In addition, 1, 1/2, 1
A point described as / 4 ... is a point existing on the virtual confusion color straight line OQ when the O point is 0 and the Q point is 1.

In (a), the color of point O and point Q are measured by the subject.
This is the case where it is judged that the colors are different, the points R1 and R2 are inspected, and the point R is obtained as the final color distinguishable range. (B) shows the case where the subject does not judge that the color of the point O and the color of the point Q are different, and in that case, the color distinguishable range is outside the virtual confusion color straight line O-Q. become. In that case, a point R of O-Q = Q-R1 is determined, and Q-R1 is inspected as points R2 and R3 in the same manner as in the case of (a) to obtain a point R as a final color distinguishable range.

Since humans cannot recognize the difference in color in the thus obtained ellipse, it is useful for selecting or limiting the colors used in the industrial field or in the expressive fields such as printing and television.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a chromaticity diagram.

FIG. 2 is an explanatory diagram of color blindness.

FIG. 3 is an explanatory diagram of a color vision test.

FIG. 4 is an example of a display screen.

FIG. 5 is an explanatory diagram of a binary search method.

FIG. 6 is an explanatory diagram of an ellipse of MacAdam.

FIG. 7 is an explanatory diagram of an application example.

FIG. 8 is an explanatory diagram of a binary search method of an application example.

[Explanation of symbols]

1 Chromaticity diagram curve 2 Color display range by CRT display 3 Color display range by TFT liquid crystal display 4 CRT display 5,6 rectangle 7 black line C, O center point P, D, T mixed color center Ellipse of M MacAdam Q yen E ellipse

   ─────────────────────────────────────────────────── ─── Continued front page    (71) Applicant 501423894             Atsushi Murakami             12-5 Umedacho, Shimizu City, Shizuoka Prefecture (71) Applicant 501423908             SBS Information System Co., Ltd.             3-1-1 Toro, Shizuoka City, Shizuoka Prefecture (72) Inventor Mitsuaki Katsuya             2255-4323 Suyama, Susono City, Shizuoka Prefecture (72) Inventor Hiroshi Fukuda             25-18-202 Yata, Shizuoka City, Shizuoka Prefecture (72) Inventor Shogo Uematsu             519-1 Orido, Shimizu City, Shizuoka Prefecture (72) Inventor Atsushi Murakami             12-5 Umedacho, Shimizu City, Shizuoka Prefecture

Claims (12)

[Claims] 1. A color vision inspection method in which two colors having the same lightness existing on a confusion color line of dichroic color vision are displayed on a color display, and the color vision ability is judged based on whether or not these two colors can be discriminated. 2. The color vision inspection method according to claim 1, wherein the two colors displayed are additive color mixture controlled by a computer. 3. The color vision inspection method according to claim 1, wherein one of the two displayed colors is an achromatic color. 4. A color vision ability is judged by displaying two colors existing on a color line orthogonal to a confusion color line of a dichroic color vision deficient person and judging whether or not these two colors can be discriminated. 1. The color vision inspection method according to claim 2 or claim 3. 5. The color vision inspection method according to claim 1, claim 2, claim 3 or claim 4, wherein the two colors displayed are selected by a binary search method. 6. The color vision test method according to claim 1, claim 2, claim 3, claim 4, or claim 5, wherein the test is repeated if there is an error in the test result. 7. A color display for displaying two colors of the same lightness existing on a confusion color line of two-color type color vision, and adding two colors existing on the confusion color line of two-color type color vision displayed on the color display. Computer controlled by mixing,
A color vision inspection device comprising an input device for inputting the difference between two displayed colors. 8. The color vision inspection apparatus according to claim 7, wherein one of the two displayed colors is an achromatic color. 9. The method according to claim 9, further comprising displaying two colors existing on a color line orthogonal to the confusion color line of the dichroic color vision deficient person, and determining the color vision ability based on whether or not the two colors can be discriminated. 7. The color vision inspection device according to claim 7 or 8. 10. The color vision test apparatus according to claim 7, 8 or 9, wherein the two displayed colors are selected by a binary search method. 11. The method according to claim 7, claim 8, claim 9, or claim 10, wherein the test is redone when there is an error in the test result.
Color vision inspection device. 12. Assuming a circle having a diameter slightly larger than the major axis of the MacAdam ellipse predicted near the measurement target color on the chromaticity diagram, a plurality of circles passing through the position of the measurement target color on the chromaticity diagram are assumed. A diameter is set, an intersection of the plurality of diameters and the circle is determined, computer data of the color to be measured and the intersection is determined, and two colors of the same brightness existing on each of the plurality of diameters are determined. A method for investigating color discrimination ability, wherein the color discrimination ability is displayed, the color discrimination ability is judged based on whether or not these two colors can be discriminated, and the two displayed colors are selected by a binary search method.