Visual characteristic inspection image set, visual characteristic inspection method, correction filter characteristic determination method, and correction filter

Abstract

Provided are: a visual characteristics inspection method that imposes little burden on a subject and enables inspection of visual characteristics of the subject; an inspection image set used for inspection of visual characteristics; a method for determining characteristics of a compensation filter on the basis of results of inspection of visual characteristics; and a compensation filter that is created by the same. The inspection image set comprises a plurality of inspection images that are used for inspection of visual characteristics of the subject. Each of the inspection images comprises a background region and an inspection region that is provided inside the background region. The inspection region has provided therein a figure in which at least one of the R, G, and B components in the RGB color space is different with respective to the background region. The respective inspection images contain at least one color that is different between the background region and the inspection region.

Description

[Technical Field]

[0001] The present invention relates to a test image set for visual characteristics, a method for testing visual characteristics, a method for determining characteristics of a correction filter, and a correction filter. [Background technology]

[0002] Known human visual disorders include color blindness and color weakness, which are conditions in which the patient is insensitive to light in certain wavelength bands, and photosensitivity, which is the sensitivity to light of certain wavelengths. An example of photosensitivity is Aaron syndrome. These visual disorders occur when the sensitivity of the three cone cells (S-cones, M-cones, and L-cones) and rod cells in the retina is higher or lower than that of a healthy individual. S-cones, M-cones, and L-cones respond to blue, green, and red light, respectively. Rod cells respond to the intensity of light. A person's sensitivity to light also varies depending on the brightness of the surroundings. Sensitivity in bright places is called photopic vision, and sensitivity in dark places is called scotopic vision. Photopic vision is primarily responsible for cone fibrillation, while scotopic vision is primarily responsible for rod cells (see Figure 3). Sensitivity in brightness levels between the two is called mesopic vision. Mesopic vision is driven by both cone and rod cells. A known method for correcting the vision of visually impaired patients is to use optical filters whose light transmission characteristics are tailored to each individual. By having the patient wear eyeglasses with the optical filters whose characteristics have been tailored, the patient's visual impairment is alleviated.

[0003] To create an optical filter tailored to a patient, it is necessary to test the patient's visual characteristics (sensitivity) to various colors of light. However, because there are countless combinations of sensitivity to various colors of light, testing visual characteristics is a heavy burden for both the examiner and the patient.

[0004] Methods for producing optical filters tailored to patients have been known for some time. For example, Japanese Patent Laid-Open Publication No. 6-18819 describes a method for producing eyeglasses that classify the color vision characteristics of patients. In the eyeglasses production method described in Patent Document 1, color vision characteristics are classified into 32 types based on the color vision characteristic test results of multiple patients. In Patent Document 1, the patient's color vision characteristics are tested to determine which of the 32 color vision characteristics they fall into. The characteristics of the optical filter are determined based on the test results, thereby alleviating the patient's color vision deficiency. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 6-18819 Summary of the Invention [Problem to be solved by the invention]

[0006] The color vision testing method described in Patent Document 1 determines which of predetermined categories a patient's color vision characteristics falls into. Therefore, there is a problem that accurate test results cannot be obtained for patients whose color vision characteristics do not fall into any of the predetermined categories or whose color vision characteristics are intermediate between multiple categories. Furthermore, the color vision testing method described in Patent Document 1 classifies color vision characteristics according to the wavelength range to which cone cells are sensitive, and does not take into account the sensitivity of rod cells. Therefore, there is a problem that the color vision testing method described in Patent Document 1 cannot test abnormalities in visual characteristics caused by the influence of rod cells. Furthermore, Patent Document 1 does not take into account photopic vision, scotopic vision, and mesopic vision, which are affected by the combined sensitivity of cone cells and rod cells.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a visual characteristics testing method that places little burden on a subject and enables testing of the subject's visual characteristics, a test image set used for testing visual characteristics, a method for determining characteristics of a correction filter based on the visual characteristics test results, and a correction filter created thereby. [Means for solving the problem]

[0008] A test image set according to one embodiment of the present invention is a test image set used to test the visual characteristics of a subject, and includes a plurality of test images, each of which has a background region and a test region set within the background region, and within the test region is a shape whose color differs from the color of the background region in at least one of the R, G, and B components in the RGB color space, and the plurality of test images have at least one color different between the background region and the test region.

[0009] A visual characteristics testing method according to one embodiment of the present invention is a method for testing the visual characteristics of a subject using test images included in the test image set. The visual characteristics testing method includes a presentation step of sequentially presenting test images included in the test image set to the subject, and a first determination step of determining whether the test images presented in the presentation step satisfy predetermined test conditions when the subject views the test images.

[0010] A method for determining characteristics of a correction filter according to one embodiment of the present invention includes, in the above-described visual characteristic inspection method, a determination step of determining the transmittance of a correction filter that adjusts the intensity of transmitted light, based on the color of an inspection image that satisfies predetermined inspection conditions.

[0011] A correction filter according to one embodiment of the present invention has a transmittance determined by the above-described method for determining characteristics of a correction filter. [Effects of the Invention]

[0012] According to embodiments of the present invention, there are provided a visual characteristics testing method that places little strain on a subject and enables testing of the subject's visual characteristics, a test image set used for testing visual characteristics, a method for determining characteristics of a correction filter based on the visual characteristics test results, and a correction filter created thereby. [Brief explanation of the drawings]

[0013] [Figure 1]FIG. 1 is a schematic diagram of a visual inspection system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing an example of the absorption spectra of human cone cells (S cone cells, M cone cells, L cone cells) and rod cells. [Figure 3] FIG. 3 is a diagram showing human photopic vision and scotopic vision. [Figure 4] FIG. 4 is a diagram showing an example of an inspection image according to an embodiment of the present invention. [Figure 5] FIG. 5 is a flowchart of a visual inspection method according to an embodiment of the present invention. [Figure 6] FIG. 6 is a diagram illustrating an example of a correction filter according to an embodiment of the present invention. [Figure 7] FIG. 7 shows the bandwidth of a compensation filter according to an embodiment of the present invention. [Figure 8] FIG. 8 is a diagram illustrating an example of the characteristics of the correction filter according to the embodiment of the present invention. [Figure 9] FIG. 9 is a diagram illustrating an example of the characteristics of the correction filter according to the embodiment of the present invention. [Figure 10] FIG. 10 is a diagram illustrating an example of the characteristics of the correction filter according to the embodiment of the present invention. [Figure 11] FIG. 11 is a diagram showing an example of an inspection image according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0015] [Visual inspection system] 1 is a schematic diagram of a visual inspection system 1 for performing a visual inspection in one embodiment of the present invention. The visual inspection system 1 includes a display device 100 and a shading hood 200, and is used to inspect the visual characteristics of a subject 500.

[0016] The display device 100 is, for example, a liquid crystal display or a CRT (Cathode Ray Tube) display. The display device 100 displays an examination image 110. Note that the display device 100 is not limited to a device that displays an image in response to an image signal, such as a liquid crystal display, as long as it can show the examination image 110 to the subject 500. For example, the display device 100 may include a film on which the examination image 110 is printed and a backlight that irradiates the film with illumination light, and present the examination image 110 to the subject 500 by irradiating the film with the illumination light.

[0017] The display device 100 is covered with a light-shielding hood 200. The light-shielding hood 200 prevents external light from irradiating the test image 110 and changing the brightness and color of the test image 110 as seen by the subject 500. The inside of the light-shielding hood 200 is preferably black, which absorbs light, to prevent light reflection and affect the visual test.

[0018] In the visual test, the subject 500 looks at the test image 110 with one or both eyes. Then, the degree to which the subject 500 perceives the test image 110 as dazzling (i.e., the degree of photosensitivity of the subject 500) and the subject's perception of the color of the test image 110 (i.e., the subject's 500 color vision) are tested.

[0019] When the visual characteristics of the subject 500 are tested by a visual test, a correction filter that corrects the visual characteristics of the subject 500 can be produced based on the test results. Note that the test results may be used not only to produce a correction filter, but also to adjust the brightness and color of a lighting device and a monitor such as a television or mobile terminal used by the subject 500 to match the visual characteristics of the subject 500.

[0020] Figure 2 shows an example of the absorption spectra of human cone cells (S cone cells, M cone cells, and L cone cells) and rod cells. The horizontal axis of Figure 2 represents the wavelength of light, and the vertical axis represents the absorption rate of each cone cell and rod cell. "S," "M," "L," and "Rod" in Figure 2 represent the absorption spectra of S cone cells, M cone cells, L cone cells, and rod cells, respectively. Each absorption spectrum shown in Figure 2 is normalized by the maximum absorption rate. The higher the absorption rate of each cone cell and rod cell, the higher its sensitivity (susceptibility) to that light. S cone cells have their maximum sensitivity around 420 nm. M cone cells have their maximum sensitivity around 534 nm. L cone cells have their maximum sensitivity around 564 nm. Rod cells have their maximum sensitivity around 498 nm. Note that the wavelengths at which each cone and rod cell is most sensitive vary from person to person.

[0021] Figure 3 shows human photopic and scotopic vision. The horizontal axis of Figure 3 represents the wavelength of light, and the vertical axis represents the human sensitivity to each wavelength. Photopic vision is represented by a solid line, while scotopic vision is represented by a dashed line. Human sensitivity to light differs between bright and dark places. Because photopic vision is primarily performed by cone cells, in bright places, humans are thought to recognize color using M and L cone cells, while the remaining S cone cells recognize brightness. On the other hand, because scotopic vision is primarily performed by rod cells, humans are thought to recognize brightness using rod cells in dark places. Therefore, people with high sensitivity of S cone cells and rod cells, which are used to recognize brightness, experience symptoms of photosensitivity, where light is perceived as dazzling. Furthermore, people with a difference in sensitivity between M cone cells and L cone cells, which are used to recognize color (i.e., sensitivity to green light and sensitivity to red light), experience symptoms of color weakness or color blindness. Color deficiency includes, for example, type 1 color deficiency, which is a reduced sensitivity to red light, and type 2 color deficiency, which is a reduced sensitivity to green light.

[0022] [Inspection image set] Next, the test image set will be described. The test image set is a set of a plurality of test images. The test images are displayed on the display device 100. FIG. 4 shows an example of a test image 110.

[0023] The inspection image 110 has an inspection area 120 located near the center of the inspection image 110 and a surrounding background area 130. In FIG. 4, the inspection area 120 is the area surrounded by a dashed line. This dashed line is drawn for the purpose of explaining the inspection area 120 and is not included in the inspection image 110. A figure 121 is located in the inspection area 120. The figure 121 and the background area 130 have different colors. Furthermore, the area of the inspection area 120 other than the figure 121 has the same color as the background area 130. In the example shown in FIG. 4, the background area 130 has a circular shape. Furthermore, a peripheral area 140 further outside the background area 130 is black.

[0024] 4, the figure 121 is a Landolt ring that is typically used in visual acuity tests, but the embodiment of the present application is not limited to this. The figure 121 may be any shape that a person can recognize, such as a letter, a number, a circle, a square, or the like. The figure 121 may also be a combination of multiple letters or shapes.

[0025] The inspection area 120 is an area corresponding to the fovea centralis on a human retina. The size of the inspection area 120 is set so that light emitted from the inspection area 120 forms an image within the fovea centralis. For example, the size of the inspection area 120 is determined by the apex angle θ of a cone with the inspection area 120 as the base and the eye of the subject 500 as the apex. IN (See Figure 1) The apex angle θ of about 2 degrees is set to be approximately 2 degrees. IN corresponds to the width of the visual field (i.e., the visual field angle) of the fovea. The diameter of the inspection area 120 varies depending on the distance between the subject 500 and the display device 100 of the visual inspection system 1. The size of the inspection area 120 only needs to be set so that the light emitted from the inspection area 120 forms an image within the fovea, and the apex angle θ IN does not have to be exactly twice.

[0026] The background region 130 corresponds to the region around the fovea centralis on the human retina. The size of the background region 130 is set so that light emitted from the background region 130 forms an image outside the fovea centralis on the human retina. For example, the size of the background region 130 is determined by the apex angle θ of a cone with the background region 130 as the base and the eye of the subject 500 as the apex. OUT (See FIG. 1) is set to be approximately 40 degrees (See FIG. 1). When the fovea is set to the center of the visual field (0 degrees), rod cells are mostly arranged around ±20 degrees. Therefore, the background region 130 is set to have an apex angle θ OUT It is desirable that the angle is set to 40 degrees or more. The shape of the background region 130 is not limited to a circle. If the display screen of the display device 100 is rectangular, the entire area of the display screen other than the inspection region 120 may be the background region 130.

[0027] The fovea of the human retina contains many M cones, which are sensitive to green light, and many L cones, which are sensitive to red light. The fovea also contains very few S cones and rods. On the other hand, the area outside the fovea contains S, M, and L cones and rods.

[0028] Human visual acuity is improved when the fovea is used. When viewing objects, images, or text, people primarily use the M and L cone cells located in the fovea to recognize the shape and color of the object. In other words, people can recognize color using only the M and L cone cells. Furthermore, people recognize not only color but also brightness using the S and M cone cells and rod cells around the fovea. Therefore, it is possible to test a person's color vision by conducting a visual test targeting the M and L cone cells in the fovea. Furthermore, it is possible to test the degree of light sensitivity by conducting a test targeting the fovea and the S cone and rod cells around the fovea.

[0029] The figure 121 in the test area 120 is an area used to test color vision using the M and L cone cells in the fovea, and has a chromatic color. In this embodiment, the background area 130 is achromatic. That is, in the background area 130, the R, G, and B components in the RGB color space have the same magnitude. This is because if a chromatic color were used in the background area 130, the color of the background area 130 could affect the color vision test using the test area 120. The color of the background area 130 must include a color to which rod cells are sensitive. For example, the color of the background area 130 is a color other than black (i.e., the magnitude of the R, G, and B components is zero). The color of the background area 130 may also be white. The background area 130 does not need to be a uniform color throughout, and may include areas of relatively low and high brightness.

[0030] The test image set includes multiple test images 110 in which the colors of the figures 121 or the colors of the background regions 130 are different from one another. As an example, in this embodiment, the test image set includes 345 types of test images 110 in which the colors of the test images 110 are different from one another. Specifically, the test image set includes 115 types of test images 110B in which the colors of the blue components are different from one another, 115 types of test images 110R in which the colors of the red components are different, and 115 types of test images 110G in which the colors of the green components are different from one another, relative to the background regions 130. Test image 110B is a test image for testing the sensitivity of test subject 500 to blue light. Test image 110R is a test image for testing the sensitivity of test subject 500 to red light. Test image 110G is a test image for testing the sensitivity of test subject 500 to green light.

[0031] The colors of the plurality of inspection images 110B, each having a different color background region 130, are set so that the brightness of the background region 130 changes in increments of 5% or 10%, for example. The colors of the plurality of inspection images 110G, each having a different color background region 130, are set so that the brightness of the background region 130 changes in increments of 5% or 10%, for example. The colors of the plurality of inspection images 110R, each having a different color background region 130, are set so that the brightness of the background region 130 changes in increments of 5% or 10%. Note that the increments of the brightness of the background region 130 are not limited to 5% or 10%.

[0032] Since the inspection image 110 is displayed on the display device 100, the inspection image 110 is displayed after undergoing gamma correction according to the gamma value of the display device 100. In more detail, when the input value of the image signal input to the display device 100 is x, the output value (luminance) is y, and the gamma value of the display device 100 is γ, then y=x γ Therefore, the input value for changing the luminance y on the display device 100 is x=y 1 / γ In this embodiment, the RGB components of the inspection image 110 are the input values (xR, xG, xB) to the display device 100, and each input value is expressed in 256 gradations from 0 to 255. The RGB components of the background region 130 are the input values (xR BG ,xG BG ,xB BG ) and each input value is represented in 256 levels from 0 to 255.

[0033] Table 1 shows the input values (xR BG ,xG BG ,xB BG ) and the input values (xR, xG, xB) of figure 121.

[0034] [Table 1]

[0035] The "brightness [%] of the background region" in Table 1 represents the brightness when the brightness of the background region 130 is white (i.e., the input value is (255, 255, 255)) is 100%. The "color component of the background region" represents the input value (xR BG ,xG BG ,xB BG ) are shown. In this embodiment, there are 11 types of background regions 130B (5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, and 100%). In this embodiment, the background regions 130B are achromatic, so the RGB color components in each background region 130B have the same size.

[0036] The "difference [%] of blue component of figure 121 from background region 130" in the table represents the difference in luminance of the blue component of figure 121 from the luminance of the blue component of background region 130, assuming that the luminance of the blue component of background region 130 is 100%. In this embodiment, there are 12 different 10% increments of the difference [%] of the blue component of figure 121 from background region 130, ranging from -60% to +60%. Note that in this embodiment, the size of the red and green components of background region 130 is the same as the size of the red and green components of figure 121. Therefore, when the difference [%] of the blue component of figure 121 from background region 130 is 0%, figure 121 and background region 130 are the same color, and therefore are not included in inspection image 110B.

[0037] Each inspection image 110B is a combination of a background region 130 and a graphic 121 with an input value listed in the same column as the background region 130. For example, there are six types of inspection images 110B in which the input value of the background region 130 is (255, 255, 255). The red and green components of the graphic 121 in these six types of inspection images 110B are the same in magnitude as the red and green components of the background region 130 (i.e., both are 255). Furthermore, the blue input values of the graphic 121 in these six types of inspection images 110B are set so that their brightness varies in 10% increments from -60% to -10% relative to the blue input value of the background region 130. The blue input values of the graphic 121 in the six types of inspection images 110B in which the input value of the background region 130 is (255, 255, 255) are 168, 186, 202, 217, 230, and 243, respectively.

[0038] In Table 1, when the input value of background region 130 is (255, 255, 255), the input value of figure 121 whose difference [%] in the blue component from background region 130 is +10% or more is not listed because the maximum input value of blue for figure 121 is 255. Similarly, when the color components of background region 130 are (243, 243, 243), (230, 230, 230), or (217, 217, 217), no cases where the input value of blue exceeds 255 are listed.

[0039] When the difference [%] of the blue component of the figure 121 from the background region 130 is a positive value (+10% to +60), the magnitude of the blue component is greater than the red and green components, and the figure 121 has a bluish color. The greater the difference [%] of the blue component from the background region 130, the stronger the blueness, and the more distinct the color difference between the figure 121 and the background region 130. On the other hand, when the difference [%] of the blue component of the figure 121 from the background region 130 is a negative value (-10% to -60), the red and green components are greater than the blue component, and the figure 121 has a yellowish color (a color with strong greenish and reddish hues). The smaller the difference [%] of the blue component from the background region 130, the stronger the yellowness, and the more distinct the color difference between the figure 121 and the background region 130.

[0040] A subject with normal color vision can easily recognize the color difference between the figure 121 and the background region 130 even when the absolute value of the difference [%] of the blue component from the background region 130 is small. On the other hand, in order for a subject with relatively low sensitivity to blue light to recognize the color difference between the figure 121 and the background region 130, the absolute value of the difference [%] of the blue component from the background region 130 needs to be large. A subject with normal color vision can recognize the figure 121 in the background region 130, for example, when the absolute value of the difference [%] of the blue component from the background region 130 is 30% or more (i.e., −30% or less or +30% or more). On the other hand, a subject with low sensitivity to blue light cannot recognize the figure 121 even when the absolute value of the difference [%] of the blue component from the background region 130 is 30%, but can recognize the figure 121 in the background region 130 when, for example, the absolute value of the difference [%] of the blue component from the background region 130 is 40% or more. Furthermore, if the subject has photosensitivity, the subject is highly sensitive to blue light, and therefore can recognize the figure 121 in the background region 130 even if the absolute value of the difference [%] of the blue component from the background region 130 is less than 30%.

[0041] Furthermore, subjects with normal color vision generally find it easier to recognize the color difference between the background region 130 and the figure 121 as the luminance of the background region 130 and the figure 121 increases. On the other hand, if a subject has photosensitivity, which is sensitive to blue light, the high luminance of the background region 130 and the figure 121 can cause the subject to feel dazzled by the test image 110B. Therefore, for a subject with photosensitivity, it is easier to recognize the color difference between the background region 130 and the figure 121 when the "luminance [%] of the background region" is lower than 100%. Furthermore, even if a subject has photosensitivity, reducing the luminance [%] of the background region 130 may make it difficult for the subject to recognize the figure 121 in the background region 130 if the absolute value of the difference [%] of the blue component from the background region 130 is less than 30%. In this case, if the brightness [%] of the background region 130 is reduced, the absolute value of the difference [%] of the blue component from the background region 130 must be changed to 30% or more so that the subject can recognize the figure 121 within the background region 130.

[0042] Thus, the conditions for recognizing the color difference between the background region 130 and the figure 121 (in other words, recognizing the figure 121 within the background region 130) vary depending on the subject's color vision characteristics. Therefore, by using multiple test images 110B with different luminances (luminances of the background region 130 and the figure 121) and different color differences between the figure 121 and the background region 130, the subject's color vision characteristics for blue light can be determined. Table 1 shows examples of test images 110B in which the difference [%] of the blue component of the figure 121 from the background region 130 ranges from -60% to +60%, but the test images 110B are not limited to these. For example, test images 110B in which the difference [%] of the blue component of the figure 121 from the background region 130 is less than -60% or test images 110B in which the difference [%] of the blue component of the figure 121 from the background region 130 is greater than +60% may be prepared.

[0043] Tables 2 and 3 show the input values (xR BG ,xG BG ,xB BG ) and the input values (xR, xG, xB) of figure 121.

[0044] [Table 2]

[0045] [Table 3]

[0046] In the inspection image 110R shown in Table 2, when the difference [%] of the red component of the figure 121 from the background region 130 is a positive value (+10% to +60), the magnitude of the red component is greater than the green and blue components, and therefore the figure 121 has a reddish color. The greater the difference [%] of the red component from the background region 130, the stronger the redness, and the more obvious the difference in color between the figure 121 and the background region 130. On the other hand, when the difference [%] of the red component of the figure 121 from the background region 130 is a negative value (-10% to -60), the green and blue components are greater than the red component, and therefore the figure 121 has a cyan color (a color with strong greenish and blueish hues). The smaller the difference [%] of the red component from the background region 130, the more obvious the cyan color, and the more obvious the difference in color between the figure 121 and the background region 130.

[0047] In the inspection image 110G shown in Table 3, when the difference [%] of the green component of the pattern 121 from the background region 130 is a positive value (+10% to +60%), the magnitude of the green component is greater than the red and blue components, and the pattern 121 has a greenish color. The greater the difference [%] of the green component from the background region 130, the stronger the green color, and the more obvious the color difference between the pattern 121 and the background region 130. On the other hand, when the difference [%] of the green component of the pattern 121 from the background region 130 is a negative value (-10% to -60), the red and blue components are greater than the green component, and the pattern 121 has a magenta color (a color with strong reddish and blueish hues). The smaller the difference [%] of the green component from the background region 130, the more obvious the magenta color, and the more obvious the color difference between the pattern 121 and the background region 130.

[0048] As with test image 110B, in test images 110R and 110G, subject 500 with normal color vision can easily recognize the color difference between figure 121 and background region 130 even when the absolute values of the difference [%] of the red component of figure 121 from background region 130 and the difference [%] of the green component of figure 121 from background region 130 are small (i.e., when the colors of figure 121 and background region 130 are similar). On the other hand, in order for subject 500, who has a relatively low sensitivity to red and green light, to recognize the color difference between figure 121 and background region 130, the absolute values of the difference [%] of the red component of figure 121 from background region 130 and the difference [%] of the green component of figure 121 from background region 130 must be large. A subject 500 with normal color vision can recognize the figure 121 placed within the background region 130, for example, when the absolute value of the difference [%] of the red component of the figure 121 from the background region 130 or the difference [%] of the green component of the figure 121 from the background region 130 is 30% or more (i.e., −30% or less or +30% or more). On the other hand, a subject 500 with low sensitivity to red or green light cannot recognize the figure 121 even if the absolute value of the difference [%] of the red component of the figure 121 from the background region 130 or the difference [%] of the green component of the figure 121 from the background region 130 is 30%, but can recognize the figure 121 when, for example, the absolute value of the difference [%] of the red component of the figure 121 from the background region 130 or the difference [%] of the green component of the figure 121 from the background region 130 is 50% or more.

[0049] Furthermore, subjects with normal color vision generally find it easier to recognize the color difference between the background region 130 and the figure 121 as the brightness of the background region 130 and the figure 121 increases. On the other hand, if a subject has photosensitivity, which makes them highly sensitive to blue light, the test image 110B will be dazzling if the brightness of the background region 130 and the figure 121 is high. Therefore, subjects with photosensitivity find it easier to recognize the color difference between the background region 130 and the figure 121 when the "brightness [%] of the background region" is lower than 100%.

[0050] Thus, the conditions for recognizing the color difference between background region 130 and figure 121 (in other words, the conditions for recognizing figure 121 in background region 130) vary depending on the color vision characteristics of the subject. Therefore, by using multiple test images 110R, 110G in which the luminance (luminance of background region 130 and figure 121) of test images 110R, 110G and the color difference of figure 121 relative to background region 130 are different, it is possible to determine the color vision characteristics of the subject for red and green light. Note that Table 2 shows an example of test image 110R in which the difference [%] of the red component of figure 121 from background region 130 ranges from -60% to +60%, but test image 110R is not limited to these. For example, an inspection image 110R may be prepared in which the difference [%] of the red component of the figure 121 from the background region 130 is less than -60%, or an inspection image 110R in which the difference [%] of the red component of the figure 121 from the background region 130 is greater than +60%. Table 3 also shows examples of inspection images 110G in which the difference [%] of the green component of the figure 121 from the background region 130 ranges from -60% to +60%, but the inspection image 110G is not limited to these. For example, an inspection image 110G in which the difference [%] of the green component of the figure 121 from the background region 130 is less than -60%, or an inspection image 110G in which the difference [%] of the green component of the figure 121 from the background region 130 is greater than +60% may be prepared.

[0051] [Visual inspection method] Next, a description will be given of a visual inspection method using the visual inspection system 1 including the inspection image 110. FIG.

[0052] [Processing step S101 in Figure 5] In step S101, the appropriate brightness B is the brightness [%] of the background region 130 of the test image 110 that is appropriate for the subject 500. CENTER is identified.

[0053] In S101, first, inspection images 110B in which the difference [%] of the blue component of figure 121 from background region 130 is −30% are sequentially displayed on display device 100 while the brightness [%] of background region 130 is changed. The displayed inspection images 110B may be displayed in ascending or descending order of the brightness [%] of background region 130. Alternatively, inspection images 110B may be displayed in descending order of the brightness [%] of background region 130, and then in descending order of the brightness [%] of background region 130. Alternatively, the brightness [%] of background region 130 may be changed randomly. When the brightness [%] of background region 130 changes, the color component of figure 121 also changes accordingly, while the blue component of figure 121 relative to the blue component of background region 130 remains −30%. The time for which one test image 110B is displayed is, for example, the time during which the subject 500 can confirm whether or not the test image 110B is dazzling and whether or not he or she can recognize the figure 121, and then respond with the results of the confirmation. For example, one test image 110B is displayed for one second or more, and then the next test image 110B, which has a different luminance [%] of the background region 130, is displayed. If the figure 121 is a Landolt ring, whether or not the subject 500 can recognize the figure 121 can be confirmed by whether or not the subject 500 can see the position where the Landolt ring is interrupted (the right side in the example of FIG. 4).

[0054] If the subject 500 has normal visual sensitivity to blue light, the subject 500 is likely to be able to recognize the figure 121 in the background region 130 regardless of the luminance [%] of the background region 130. If the subject 500 has photosensitivity, the subject 500 will feel dazzled by the test image 110B when the luminance [%] of the background region 130 is high. Therefore, the subject 500 with photosensitivity will have difficulty recognizing the figure 121 in the test image 110B where the luminance [%] of the background region 130 is relatively high, but will easily recognize the figure 121 in the test image 110B where the luminance [%] of the background region 130 is relatively low. On the other hand, if the subject 500 has low luminosity sensitivity to blue light, the subject 500 will have difficulty recognizing changes in the blue component of the figure 121, and may not be able to recognize the figure 121 in the test image 110B where the difference [%] of the blue component of the figure 121 from the background region 130 is -30%. Therefore, by testing whether the subject 500 can recognize the figure 121 in the background area 130, it is possible to test the subject 500's sensitivity to blue light, or the difference between the subject 500's sensitivity to blue light and that of a healthy person.

[0055] If subject 500 can recognize figure 121 in test image 110B where the difference [%] of the blue component of figure 121 from background region 130 is -30%, this means that subject 500's sensitivity to blue light is at least as high as that of a healthy subject. On the other hand, if subject 500 cannot recognize figure 121 in test image 110B where the difference [%] of the blue component of figure 121 from background region 130 is -30%, this means that subject 500's sensitivity to blue light is lower than that of a healthy subject. Furthermore, since subject 500 with photosensitivity has a high sensitivity to blue light, he or she may be able to recognize figure 121 in test image 110B even when the difference [%] of the blue component of figure 121 from background region 130 is greater than -30% (i.e., the color of figure 121 is closer to the color of background region 130) when the brightness [%] of background region 130 is lower than 100%.

[0056] The subject 500 identifies the brightness [%] of the background region 130 at which the figure 121 can be recognized while viewing the test image 110B in which the brightness [%] of the background region 130 changes. Then, the median (or a value close to the median) of the range of brightness [%] of the background region 130 at which the subject 500 can recognize the figure 121 is defined as the appropriate brightness B CENTER The appropriate brightness B CENTER may be the maximum brightness value within the range of brightness [%] of the background region 130 at which the subject 500 can recognize the figure 121. If the subject 500 can recognize the figure 121 regardless of the brightness [%] of the background region 130, 100% is set as the appropriate brightness B CENTER The fact that the subject 500 can recognize the figure 121 is an example of the first inspection condition.

[0057] If the subject 500 cannot recognize the figure 121 in the test image 110B where the difference [%] of the blue component of the figure 121 from the background region 130 is -30%, the test image 110B where the difference [%] of the blue component of the figure 121 from the background region 130 is -40% is displayed. Then, the subject 500 is tested to see if he or she can recognize the figure 121 in the background region 130 of the displayed test image 110B. At this time, the brightness [%] of the background region 130 of the displayed test image 110B may be sequentially changed. If the subject 500 cannot recognize the figure 121 in the test image 110B where the difference [%] of the blue component of the figure 121 from the background region 130 is -40%, the test image 110B is displayed with the difference [%] of the blue component of the figure 121 from the background region 130 set even lower. In this way, the difference [%] of the blue component of figure 121 from background region 130 is changed until subject 500 can recognize figure 121. This makes it possible to test how much lower subject 500's sensitivity to blue light is compared to that of a healthy subject. If subject 500 can recognize figure 121 in test image 110B in which the difference [%] of the blue component of figure 121 from background region 130 is -30%, test image 110B in which the difference [%] of the blue component of figure 121 from background region 130 is closer to 0 (for example, -20% or -10%) may be displayed to test whether subject 500 can recognize figure 121.

[0058] In the process of S101, inspection image 110B is initially displayed with a difference [%] of the blue component of figure 121 from background region 130 of -30%, and the difference [%] of the blue component of figure 121 from background region 130 is changed to a lower value depending on the inspection results. However, embodiments of the present invention are not limited to this process. For example, inspection image 110B may initially be displayed with a difference [%] of the blue component of figure 121 from background region 130 of +30%, and the difference [%] of the blue component of figure 121 from background region 130 of the displayed inspection image 110B may be changed to a higher value depending on the inspection results. Alternatively, inspection image 110B may initially be displayed with a small absolute value of the difference [%] of the blue component of figure 121 from background region 130 (e.g., -10% or +10%), and the absolute value of the difference [%] of the blue component of figure 121 from background region 130 of the displayed inspection image 110B may be changed to a larger value depending on the inspection results. Alternatively, inspection image 110B may be initially displayed with a large absolute value of the difference [%] of the blue component of figure 121 from background region 130 (e.g., -60% or +60%), and then, depending on the inspection results, the absolute value of the difference [%] of the blue component of figure 121 from background region 130 of the displayed inspection image 110B may be changed to a smaller value.

[0059] [Processing step S102 in Figure 5] In S102, the subject 500 selects a specific red component R that is a red component that allows the subject 500 to recognize the figure 121 in the background region 130 of the test image 110R. VALUE is measured. Specifically, the difference [%] in the red component at which the subject 500 can recognize the figure 121 in the background region 130 from the background region 130 is identified. Being able to recognize the figure 121 in the background region 130 specifically means being able to recognize the difference in color between the figure 121 and the background region 130 and being able to distinguish the figure 121 in the background region 130. Note that the subject 500 being able to recognize the figure 121 is an example of a second test condition.

[0060] In S102, the inspection image 110R is sequentially displayed on the display device 100 while changing the difference [%] of the red component of the figure 121 from the background region 130 from -10% to -60%. At this time, the brightness [%] of the background region 130 of the inspection image 110R is adjusted to the appropriate brightness B specified in S101. CENTER is set to

[0061] In test image 110R in which the difference [%] of the red component of figure 121 from background region 130 is -10%, the size of the red component of figure 121 is 10% smaller than the size of the green component. As the red component of figure 121 becomes smaller (as the difference [%] of the red component from background region 130 approaches -60%), the difference between the red and green components of figure 121 increases, and the color difference between figure 121 and background region 130 also increases. If subject 500 has normal visual characteristics for red and green light, subject 500 is likely to be able to recognize figure 121 within background region 130 in test image 110R in which the difference [%] of the red component of figure 121 from background region 130 is -30% or less. On the other hand, if subject 500 has a relatively low sensitivity to red light, he or she may not be able to recognize figure 121 in test image 110R in which the difference [%] of the red component of figure 121 from background region 130 is -30%. Therefore, by testing whether subject 500 can recognize figure 121 in background region 130, it is possible to test subject 500's sensitivity to red light, or the difference between subject 500's sensitivity to red light and that of a healthy subject. In other words, it is possible to test the sensitivity of subject 500's L cone cells, or the difference between subject 500's sensitivity to red light and that of a healthy subject.

[0062] If subject 500 can recognize figure 121 in test image 110R where the difference [%] of the red component of figure 121 from background region 130 is -30%, this means that subject 500's sensitivity to red light is equal to or greater than that of a healthy subject. On the other hand, if subject 500 cannot recognize figure 121 in test image 110R where the light color component of figure 121 is -30%, this means that subject 500's sensitivity to red light is lower than that of a healthy subject.

[0063] If the subject 500 cannot recognize the figure 121 in the test image 110R where the difference [%] of the red component of the figure 121 from the background region 130 is -30%, the difference [%] of the red component of the figure 121 from the background region 130 in the test image 110R is changed to -40% and displayed. Then, a test is performed to see if the subject 500 can recognize the figure 121 in the background region 130 of the displayed test image 110R. At this time, the brightness [%] of the background region 130 of the displayed test image 110R may be sequentially changed. If the subject 500 cannot recognize the figure 121 in the test image 110R where the difference [%] of the red component of the figure 121 from the background region 130 is -40%, the test image 110R is displayed with the red component of the figure 121 set even lower. In this way, test images 110R are sequentially displayed on display device 100 while changing the difference [%] of the red component of figure 121 from background region 130 from -10% to -60%, and the difference [%] of the red component from background region 130 at which subject 500 can recognize figure 121 is identified as the difference [%] of the red component from background region 130 with the smallest absolute value. In other words, of test images 110R at which subject 500 can recognize figure 121, the one in which the color of background region 130 is closest to that of figure 121 is identified. This makes it possible to test the extent to which subject 500's sensitivity to red light differs from that of a healthy subject.

[0064] In the process of S102, inspection image 110R is initially displayed with a difference [%] of the red component of figure 121 from background region 130 of -10%, and the difference [%] of the red component of figure 121 from background region 130 is changed to a lower value depending on the inspection results. However, embodiments of the present invention are not limited to this process. For example, inspection image 110R with a difference [%] of the red component of figure 121 from background region 130 of +10% may be initially displayed, and the difference [%] of the red component of figure 121 from background region 130 of the displayed inspection image 110R may be changed to a higher value depending on the inspection results. Alternatively, inspection image 110R may be initially displayed with a large absolute value of the red component of figure 121 (e.g., -60% or +60%), and the absolute value of the difference [%] of the red component of figure 121 from background region 130 of the displayed inspection image 110R may be changed to a lower value depending on the inspection results.

[0065] [Processing step S103 in Figure 5] In S103, the subject 500 selects a specific green component G, which is a green component that allows the subject 500 to recognize the figure 121 in the background region 130 of the test image 110G. VALUE Specifically, in S103, the inspection image 110G is displayed on the display device 100 in sequence while varying the difference [%] of the green component of the figure 121 from the background region 130 from -10% to -60%. At this time, the brightness [%] of the background region 130 of the inspection image 110R is measured based on the appropriate brightness B specified in S101. CENTER is set to

[0066] In S103, similar to the test in S102, it is tested whether the subject 500 can recognize the figure 121 in the background region 130 of the test image 110G. Specifically, it is tested whether the subject 500 can recognize the difference in color between the figure 121 and the background region 130, and whether he or she can identify the shape of the figure 121.

[0067] The test method in S103 is the same as the test in S102, except that test image 110G is used instead of test image 110R, and the difference [%] of the green component of figure 121 from background region 130 is changed instead of the difference [%] of the red component of figure 121 from background region 130. Specifically, test image 110G is sequentially displayed on display device 100 while the difference [%] of the green component of figure 121 from background region 130 is changed from -10% to -60%, and the difference [%] of the green component from background region 130 at which subject 500 can recognize figure 121 is identified as the difference [%] of the green component from background region 130 with the smallest absolute value. This test can test subject 500's sensitivity to green light, or the difference between subject 500's sensitivity to green light and that of a healthy subject. In other words, it is possible to examine the sensitivity of the M cone cells of the subject 500, or the difference between the sensitivity of the M cone cells of the subject 500 and the sensitivity of the M cone cells of a healthy subject.

[0068] Through the above processes from S101 to S103, the subject's sensitivity to each of the RGB lights is tested.

[0069] In the example shown in FIG. 5, both the sensitivity of the subject 500 to red light and the sensitivity of the subject 500 to green light are tested in S102 and S103, but the processing of this embodiment is not limited to this. For example, if it is known in advance that the subject 500 has low sensitivity to either green light or red light, only a test (either S102 or S103) using only the test image 110 that changes the color to which the subject 500 has low sensitivity may be performed. For example, if the subject 500 has type 1 achromatopsia, which means low sensitivity to red, the test in S102 may be performed, and the test in S103 may be omitted. Alternatively, if the subject 500 has type 2 achromatopsia, which means low sensitivity to green, the test in S103 may be performed, and the test in S102 may be omitted.

[0070] Furthermore, when only the degree of photosensitivity of the subject 500 is to be tested, only the test in S101 may be performed. The degree of photosensitivity is tested by determining at what luminance [%] of the background region 130 the subject 500 feels dazzled. Therefore, when testing the degree of photosensitivity, it is not necessarily necessary to use the test image 110B, and the test image 110R or the test image 110G may also be used.

[0071] [Processing step S104 in Figure 5] In S104, the specific red component R VALUE and specific green component G VALUE is used to calculate the ratio of the subject's 500 sensitivity to red light to that to green light.

[0072] Specific red component R VALUE The absolute value of the specific green component G VALUE If the absolute value of |G| is greater than 1, then the subject 500's sensitivity to red light is less than its sensitivity to green light. In this case, the sensitivity ratio is |G| VALUE / R VALUE |(G VALUE / R VALUE On the other hand, the specific red component R VALUE The absolute value of the specific green component G VALUE If the absolute value of |R| is smaller than |R|, then the subject 500's sensitivity to red light is greater than its sensitivity to green light. In this case, the sensitivity ratio is |R| VALUE / G VALUE |(R VALUE / G VALUE The calculated sensitivity ratio is used to determine the characteristics of a correction filter that corrects the visual characteristics of the subject 500.

[0073] [Correction filter] When the visual characteristics of the subject 500 are tested by the visual testing method shown in Fig. 5, the test results are used to create a correction filter that corrects the visual characteristics of the subject 500. The correction filter may be any filter that changes the transmission spectrum, and there are no particular limitations on the material or the principle behind changing the transmission spectrum. The correction filter is worn by the subject 500, for example, like glasses. However, there are no particular limitations on the shape of the correction filter. The correction filter may be in the form of a contact lens, or may be attached to a display device such as a television or monitor.

[0074] 6 shows an example of a glasses-like correction filter 300. The correction filter 300 includes, for example, a filter 300B for light in the blue region, a filter 300G for light in the green region, and a filter 300R for light in the red region. Each of the filters 300B, 300G, and 300R has a band B that changes the transmittance of light. B , B G , B R It has the following characteristics.

[0075] Filter 300B changes the transmittance of light in the blue region (in other words, it absorbs or reflects a portion of the blue light) but transmits green and red light unchanged (in other words, it has low absorptance or reflectance for green and red light). Filter 300G changes the transmittance of light in the green region (in other words, it absorbs or reflects a portion of the green light) but transmits blue and red light unchanged (in other words, it has low absorptance or reflectance for blue and red light). Filter 300R changes the transmittance of light in the red region (in other words, it absorbs or reflects a portion of the red light) but transmits green and blue light unchanged (in other words, it has low absorptance or reflectance for green and blue light). Therefore, by combining the three filters 300B, 300G, and 300R, it is possible to individually adjust the transmittance for light in the three RGB wavelength bands.

[0076] 7(a) to (c) show band B in which the light transmittance of three filters 300B, 300G, and 300R can be changed, respectively.B , B G , B R The horizontal axis of Figures 7(a) to (c) shows the wavelength of light, and the vertical axis shows the normalized transmittance of each filter. In Figures 7(a) to (c), the absorption spectra of each cone cell and rod cell are shown superimposed, and the vertical axis of Figures 7(a) to (c) shows the normalized absorption rate of each cell. S Peak wavelength of sensitivity of cone cells P S is approximately 420 nm, the peak wavelength of sensitivity of M cone cells P M is approximately 534 nm, the peak wavelength of sensitivity of L cone cells, P L is approximately 564 nm, the peak wavelength of sensitivity of rod cells, P Rod is approximately 498 nm, the wavelength at which photopic vision is most sensitive. Pho is approximately 570 nm (see Figure 3).

[0077] The filter 300B is positioned at the peak wavelength P of the sensitivity of the S cone cells, as shown by the solid arrow in FIG. 7(a). S (approximately 420 nm) or more, and the peak wavelength P of rod cell sensitivity Rod In other words, the transmittance of light of wavelengths equal to or less than about 498 nm can be changed. B The lower limit of P S and the upper limit is wavelength P Rod The band B of the filter 300B is B The lower limit of P S Not limited to band B B The lower limit of P S The wavelength band may be set to a shorter wavelength band than the wavelength band of the reference wavelength.

[0078] The filter 300B only needs to be able to change the transmittance of light in the blue wavelength band. B The upper limit of is the peak wavelength P of the rod cells. Rod (approximately 498 nm). B Another example of the upper limit of the band B B is indicated by a dotted arrow.

[0079] For example, the band B of the filter 300B B The upper limit of is the wavelength X where the absorption spectrum of rod cells intersects with the absorption spectrum of M cone cells. Rod-M (approximately 515 nm). Rod-M The wavelength is the peak wavelength P Rod and the peak wavelength P of M cone cells M Wavelength X (approximately 534 nm) Rod-M In the band with wavelengths longer than , the sensitivity of rod cells is relatively low and the sensitivity of M cone cells is relatively high. B The upper limit of wavelength X Rod-M If the setting is longer than this, the transmittance of light absorbed by M cone cells (light in the green wavelength band) may be changed, which may make it impossible to properly correct the visual characteristics of the subject 500.

[0080] Also, the band B of the filter 300B B The upper limit of is the peak wavelength P of rod cell sensitivity. Rod For example, the band width B of the filter 300B may be shorter than 498 nm. B The upper limit of is the wavelength X where the absorption spectrum of S cones and rods intersects. S-Rod (approximately 453 nm). S-Rod The wavelength is the peak wavelength P S and the peak wavelength P Rod Wavelength X is shorter than S-Rod In the band with wavelengths shorter than , the sensitivity of rod cells is relatively low and the sensitivity of S cone cells is relatively high. B The upper limit of wavelength X S-Rod If the setting is shorter than this, a larger proportion of light will be absorbed by the S cones, which may result in an inability to adequately compensate for light sensitivity.

[0081] In addition, in order to properly compensate for the effect of rod cells on photosensitivity, the band B of filter 300B is B The peak wavelength of rod cells is P RodTherefore, the filter 300B includes a wavelength band close to the band B B The upper limit of is the peak wavelength P of rod cell sensitivity. Rod may be shorter than the peak wavelength P Rod For example, the peak wavelength P of rod cells is Rod and wavelength X where the absorption spectrum of rod cells intersects with the absorption spectrum of M cone cells. Rod-M When the difference between the band widths is Δ, the band width B of the filter 300B is B The upper limit of P Rod By setting the range within ±Δ, the influence of rod cells on photosensitivity can be appropriately corrected.

[0082] The filter 300G is positioned at the peak sensitivity wavelength P of the rod cells, as shown by the solid line in Figure 7(b). Rod (approximately 498 nm) or more, and the wavelength X at which the absorption spectrum of M cone cells intersects with the absorption spectrum of L cone cells M-L (approximately 548 nm) or less. This wavelength X M-L The wavelength is the peak wavelength P M and the peak wavelength P L (approximately 564 nm). In other words, the band B of the 300G filter G The lower limit of the wavelength P Rod and the upper limit is wavelength X M-L is.

[0083] In order to increase the proportion of light in the wavelength band to which M cone cells are sensitive among the light transmitted through filter 300G, the band B of filter 300G is G The lower limit of is the wavelength X where the absorption spectrum of rod cells intersects with the absorption spectrum of M cone cells. Rod-M In this case, the band B of the filter 300G may be set to approximately 515 nm. G is shown by the dotted line in Fig. 7(b). As a result, only light in the wavelength band to which M cone cells are relatively sensitive compared to rod cells and other cone cells is absorbed or reflected by filter 300G.

[0084] Rod cells are cells that respond to the intensity of light and do not affect the subject's color perception (color vision). G The lower limit of the sensitivity peak wavelength of rod cells is P Rod Even if you set it to , you can still correct for green light.

[0085] The filter 300R is a filter that changes the transmittance of red light of the subject 500, and has the property of absorbing or reflecting light in the wavelength band to which the L cone cells are sensitive.

[0086] The filter 300R is configured to filter light at a wavelength X where the absorption spectrum of the M cone cell intersects with the absorption spectrum of the L cone cell, as shown by the solid line in FIG. 7(c). M-L In other words, the band B of the filter 300R is R The lower limit of wavelength X M-L is.

[0087] wavelength M-L In the band with wavelengths shorter than , the sensitivity of the L cone cells is low and the sensitivity of the M cone cells is dominant. R The lower limit of wavelength X M-L If the wavelength is set shorter than this, not only red light from the L cones but also green light may be absorbed or reflected.

[0088] Also, the band B of filter 300R R The lower limit of wavelength X M-L Instead, the wavelength P at which photopic vision is most sensitive Pho (approximately 570 nm) may also be used.

[0089] [Example 1 of correction filter] Next, an example of the correction filter will be described. B The transmittance of the appropriate brightness B specified in S101 CENTER For example, the appropriate brightness B CENTERIf it is 70%, then band B B The transmittance of the lens is set to 70%, which compensates for the photosensitivity of the subject 500.

[0090] Filter 300G Band B G Transmittance and Bandwidth of Filter 300R R The transmittance of the specific red component R is set based on the test results of S102 and S103. VALUE is specified as -30%, the sensitivity of the subject 500 to red light is approximately the same as the sensitivity of a healthy person to red light. VALUE is specified as -50%, the sensitivity of the subject 500 to green light is lower than the sensitivity of a normal person to red light. In this case, the band B of the filter 300R R The transmittance of the filter is 300G, and the band B G than the transmittance of |R VALUE / G VALUE This compensates for the difference in sensitivity of the subject 500 to red light and green light.

[0091] 8 shows an example of the characteristics of the compensation filter 300 in the above example. The horizontal axis of FIG. 8 shows wavelength [nm], and the vertical axis shows transmittance [%] of the compensation filter 300. In this example, the band B of the filter 300B B The transmittance is set to 70%, and the filter is 300G band B. G The transmittance of the filter 300R is set to 100%, and the band B R The transmittance of the filter is 300G, and the band B G than the transmittance of |R VALUE / G VALUEThe correction filter 300 has characteristics that combine the characteristics of the three filters 300R, 300G, and 300B. By using this correction filter 300, it is possible to suppress the subject 500 from feeling glare, and also to correct the difference between the sensitivity of the subject 500 to red light and the sensitivity of the subject 500 to green light.

[0092] In the example shown in Figure 8, band B B The transmittance in the region with wavelengths shorter than 10 ... B This is compensated by reducing the transmittance in band B. B The transmittance in the region with a wavelength shorter than 10 ... B In the example shown in FIG. R So, wavelength X M-L (approximately 548 nm) or longer is set to 60%. However, light with wavelengths longer than approximately 650 nm has low absorption in both cone cells and rod cells and has almost no effect on human color vision. Therefore, the transmittance of the correction filter 300 for light with wavelengths longer than approximately 650 nm may be set to any value.

[0093] [Example 2 of correction filter] Filter 300G Band B G Transmittance and Bandwidth of Filter 300R R The transmittance of the filter 300B is B For example, the transmittance of the appropriate brightness B CENTER If it is 70%, then band B B The transmittance of the specific red component R is set to 70%. VALUE is specified as -30%, and the specific green component G VALUE is specified as -50%, the band B of filter 300R RThe transmittance of the band B B Transmittance of 70% |R VALUE / G VALUE The filter 300G band width B is set to 1 / 2 times (70% × 60% = 42%). G The transmittance of the band B B The transmittance is set to 70%, the same as the transmittance of the

[0094] 9 shows an example of the characteristics of the compensation filter 300 in the above example. The horizontal axis of FIG. 9 shows wavelength [nm], and the vertical axis shows transmittance [%] of the compensation filter 300. In this example, the band B of the filter 300B B Transmittance and filter band B of 300G G The transmittance of the filter 300R is set to 70%, and the band B R The transmittance of the correction filter 300 is set to 42% (70% x 60%). By using this correction filter 300, it is possible to suppress the subject 500 from feeling glare, and also to correct the difference in sensitivity between the subject 500 to red light and the subject 500 to green light.

[0095] [Correction filter example 3] Next, an example of the correction filter 300 when the subject 500 does not have photosensitivity will be described. When the subject 500 does not have photosensitivity and has low sensitivity to blue light, the band B of the filter 300B is B Transmittance of filter 300G band B G Transmittance of filter 300R, band width B RThe transmittance of is set based on the test results of S101 to S103. For example, in the test of S101, if the subject 500 can recognize the figure 121 in the background region 130 of the test image 110B, where the difference [%] of the blue component of the figure 121 from the background region 130 is -40%, the sensitivity of the subject 500 to blue light is 75% (30 / 40) of the sensitivity of a healthy person to blue light. Also, for example, in the test of S102, if the subject 500 can recognize the figure 121 in the background region 130 of the test image 110R, where the difference [%] of the red component of the figure 121 from the background region 130 is -30%, the sensitivity of the subject 500 to red light is approximately the same as the sensitivity of a healthy person to red light. Also, for example, in the test in S103, if the subject 500 can recognize the figure 121 in the background region 130 of the test image 110G where the difference [%] of the green component of the figure 121 from the background region 130 is -50%, the sensitivity of the subject 500 to green light is 60% (30 / 50) of that of a healthy subject. In this way, by testing how much the sensitivity of the subject 500 differs from that of a healthy subject to each color of RGB light, the ratio of the sensitivity of the subject 500 to the RGB light can be found. In the above example, the band B of the filter 300B is B The transmittance of the filter is 300G, and the band B G The transmittance of the filter 300R is set to 75% of the band B. R The transmittance of the filter is 300G, and the band B G The transmittance is set to 60% of the original value.

[0096] 10 shows an example of the characteristics of the compensation filter 300 in the above example. The horizontal axis of FIG. 10 shows wavelength [nm], and the vertical axis shows transmittance [%] of the compensation filter 300. In this example, of the three colors of light, RGB, the subject 500 has the lowest sensitivity to green light, so the band B of the filter 300G is G The transmittance of the band B of the filter 300B is set to 100%. B The transmittance of the filter is 300G, and the band B G The transmittance of the filter is set to 75% of the band B. RThe transmittance of the filter is 300G, and the band B G The correction filter 300 has a relatively high transmittance for green light, to which the subject 500 has low sensitivity, and a relatively low transmittance for red light, to which the subject 500 has high sensitivity (i.e., similar to that of a healthy person). This makes it possible to correct the difference in the sensitivity of the subject 500 to R, G, and B light.

[0097] 5 is not limited to the above embodiment. For example, instead of using all of the test results S101 to S103, the characteristics of the correction filter 300 may be determined using only one or two of them. Alternatively, instead of using the difference or ratio of sensitivity of the subject 500 to RGB light, the characteristics of the filters 300B, 300G, and 300R may be determined using each of the test results S101 to S103 individually.

[0098] Furthermore, the characteristics of the correction filter 300 may be designed to match the visual characteristics of the subject 500. Alternatively, color filters with various characteristics may be prepared in advance, and the correction filter 300 may be produced by combining a plurality of color filters in accordance with the visual characteristics of the subject 500.

[0099] 5 may be used for purposes other than determining the characteristics of the correction filter 300. For example, the results of the visual test shown in Fig. 5 may be used to adjust the brightness and color of a display device (for example, a personal computer, a portable terminal device, a television, etc.) or a lighting device used by the subject 500.

[0100] [effect] According to this embodiment, test image 110 has background region 130 and test region 120 provided in background region 130, and test region 120 is provided with a figure 121 that has a predetermined color component different from that of background region 130. By using test image 110, the visual characteristics of subject 500 to light of the predetermined color component can be efficiently tested.

[0101] According to this embodiment, the presence or absence of photosensitivity in subject 500 or the degree of photosensitivity can be examined by one-dimensionally varying the luminance [%] of background region 130 in test image 110. Furthermore, by one-dimensionally varying the blue component of figure 121 in test image 110B, the green component of figure 121 in test image 110G, and the red component of figure 121 in test image 110R, respectively, subject 500's sensitivity to blue light, green light, and red light can be examined. In this way, the visual characteristics of subject 500 can be measured by one-dimensionally varying the luminance or a specific color component rather than by varying multiple color components of test image 110, thereby reducing the burden on the test.

[0102] According to this embodiment, in the test image 110, the colors of the background region 130 and the figure 121 have the same magnitude of any two of the RGB components. Therefore, when testing the visual characteristics of the subject 500 to light of the remaining component, it is possible to prevent the difference in sensitivity of the subject 500 to light of the other two components from affecting the test.

[0103] According to this embodiment, the test image set includes a plurality of test images 110 in which the background regions 130 have the same color but the figures 121 have different colors. Therefore, when visual characteristics are tested using the colors of the figures 121, the color of the background regions 130 can be prevented from affecting the test results of the visual characteristics.

[0104] According to this embodiment, the test image set includes a plurality of test images 110 each having a different color or brightness of the background region 130. Therefore, by changing the color or brightness of the background region 130 of the test image 110, the degree of photosensitivity of the subject 500 can be examined.

[0105] In this embodiment, test image 110B is used to test the sensitivity of subject 500 to blue light, test image 110G is used to test the sensitivity of subject 500 to green light, and test image 110R is used to test the sensitivity of subject 500 to red light. Therefore, it is possible to test only a specific color that is to be tested among the three colors of RGB.

[0106] The above is a description of exemplary embodiments of the present invention. The embodiments of the present invention are not limited to those described above, and various modifications are possible within the scope of the technical concept of the present invention. For example, the embodiments of the present invention also include appropriate combinations of embodiments explicitly shown as examples in the specification or obvious embodiments.

[0107] [Variation 1] In the above-described embodiment, the background region 130 of the test image 110 is achromatic and the figure 121 of the test region 120 is chromatic, but the embodiment of the present invention is not limited to this configuration. According to another embodiment of the present invention, both the background region 130 and the figure 121 may be chromatic. For example, when testing whether or not the test subject 500 has photosensitivity or the level of the test subject 500's photosensitivity, the blue component of the figure 121 in the test image 110B may be changed, and the blue component of the background region 130 may also be changed.

[0108] Tables 4 to 14 show input values (xR, xG, xB) of the background region 130 and figure 121 of the inspection image 110B in another embodiment of the present invention. The background region 130 of the inspection image 110B may be achromatic or chromatic. The red and green components of the background region 130 are the same size, and the blue component is the same size as or smaller than the red and green components. The red and green components of the figure 121 are the same size as the red and green components of the background region 130, respectively. The blue component of the figure 121 is smaller than the blue component of the background region 130.

[0109] [Table 4]

[0110]

Table 5

[0111]

Table 6

[0112]

Table 7

[0113]

Table 8

[0114]

Table 9

[0115]

Table 10

[0116]

Table 11

[0117]

Table 12

[0118]

Table 13

[0119]

Table 14

[0120] In Tables 4 to 14, the "brightness [%] of red and green components of background region" represents the brightness of the red and green components of background region 130 when the input value of the red and green components of background region 130 is 255, which is 100%. The "brightness [%] of blue component of background region" represents the brightness of the blue component of background region 130 when the input value of the blue component of background region 130 is 255, which is 100%. The "input value of background region" represents the input value (xR, xG, xB) for each brightness [%] of background region 130. In this embodiment, the inspection images 110B shown in Tables 4 to 14 have different sizes of the red and green components of the background region 130. If the brightness when the input value of the red and green components is 255 is 100%, the brightness of the red and green components of background region 130 of inspection image 110B shown in Tables 4 to 14 are 100%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, and 5%, respectively.

[0121] The "difference [%] of blue component of figure from background region" in Tables 4 to 14 represents the difference in brightness of the blue component of figure 121 from the brightness of the blue component of background region 130, assuming that the brightness of the blue component of background region 130 is 100%. In this embodiment, there are five levels of blue component [%] of figure 121, ranging from -50% to -10%, in increments of 10%.

[0122] Each inspection image 110B is a combination of a background region 130 and a graphic 121 with an input value listed in the same column as the background region 130. For example, there are five types of inspection images 110B in which the input value of the background region 130 is (255, 255, 255). The red and green components of the graphic 121 in these five types of inspection images 110B are the same magnitude as the red and green components of the background region 130 (i.e., both 255). Meanwhile, the blue input values of the graphic 121 in these five types of inspection images 110B are set so that their brightness varies in 10% increments from -50% to -10% relative to the blue input value of the background region 130. The magnitudes of the blue input values of the graphic 121 in the five types of inspection images 110B are 186, 202, 217, 230, and 243, respectively.

[0123] In the test images 110B listed in Tables 4 to 14, the brightness of the background region 130 and the figure 121 decreases from Table 4 to Table 14. Test images 110B are selected one by one from each of Tables 4 to 14 and sequentially displayed on the display device 100. Then, by checking whether or not the test subject 500 feels dazzled by the test images 110B, it is possible to check the presence or absence of photosensitivity in the test subject 500, or the degree of photosensitivity.

[0124] Furthermore, among the test images 110B that the subject 500 did not find dazzling, a table that includes the test image 110B with the highest brightness in the background region 130 and the figure 121 is selected from Tables 4 to 14. Then, the test images 110B shown in the selected table are selected one by one and sequentially displayed on the display device 100. The subject 500 selects, from the sequentially displayed test images 110B, an image in which the subject 500 can recognize the figure 121 in the background region 130, thereby testing the sensitivity of the subject 500 to blue light.

[0125] Tables 4 to 14 show modified examples of test image 110B in which the blue component of figure 121 is changed relative to chromatic background region 130, but the present invention is not limited to these examples. For example, test image 110R in which the red component of figure 121 is changed relative to chromatic background region 130, or test image 110G in which the green component of figure 121 is changed relative to chromatic background region 130, may be used to test the visual characteristics of subject 500.

[0126] [Variation 2] For example, in the above embodiment, the inspection image 110 has only one figure 121 of a single color arranged in the inspection area 120, but the embodiments of the present invention are not limited to this configuration. Two or more figures of different colors may be arranged in the inspection area of the inspection image.

[0127] 11 shows a test image 210 according to another embodiment of the present invention. Test image 210 has a test region 220 near the center and a surrounding background region 230. As with test image 110, test region 220 of test image 210 corresponds to the fovea centralis on a human retina, and background region 230 corresponds to the area surrounding the fovea centralis on a human retina. A peripheral region 240 further outside background region 230 is preferably black.

[0128] In the test area 220, a figure 221 having a green component that is different in size relative to the background area 230, and a figure 222 having a red component that is different in size relative to the background area 230 are arranged. The green component of the figure 221 and the red component of the figure 222 can be changed independently. By using this test image 210, it is possible to test both the sensitivity of the subject 500 to green light and the sensitivity to red light.

[0129] The shapes and colors of the figures to be placed in the inspection area 220 are not limited to those shown in Fig. 11. For example, figure 222 may be placed inside figure 221. Furthermore, the inspection area 220 may contain any two or all of the following three figures: a figure whose blue component is different in size from that of the background area 230; a figure whose green component is different in size from that of the background area 130; and a figure whose green component is different in size from that of the background area 130.

[0130] [Other variations] In the above embodiment, the test image 110 is displayed on the display device 100, but the embodiment of the present invention is not limited to this configuration. The test image 110 may be printed on paper, a board, or the like. In this case, multiple test images 110 with different luminances of the background region 130 and the figure 121 are printed on different papers or boards. The multiple printed test images 110 are sequentially arranged at a predetermined distance from the subject 500, illuminated with white illumination light, and presented to the subject 500. This allows the visual characteristics of the subject 500 to be tested. It is desirable that the printed test images 110 be arranged on a black background. [Explanation of symbols]

[0131] 1. Visual inspection system 100 display device 110 Inspection Images 200 Light-shielding hood 300 Correction Filter 500 subjects

Claims

1. A test image set used to test a visual characteristic of a subject, the test image set including a plurality of test images, Each of the plurality of inspection images includes: A background region; an inspection area provided within the background area; and The test area is arranged so that, when the subject looks at approximately the center of the test image, light emitted from the test area forms an image on the subject's retina in an area inside the fovea centralis. a figure having a color different from that of the background area in at least one of an R component, a G component, and a B component in an RGB color space is provided within the inspection area; the color of the background area is the same as the color of the area of the inspection area where the graphic is not provided; The plurality of inspection images have at least one color of the background region and the graphic that is different from each other. A set of visual characteristic test images.

2. the luminance of any one of the R, G, and B components of the color of the figure is different from the luminance of the predetermined component of the color of the background region; 2. The visual characteristic test image set of claim 1.

3. Among the R component, G component, and B component of the color of the figure, the magnitudes of two components other than the predetermined component are the same.

3. The visual characteristic test image set of claim 2.

4. The inspection images include a plurality of inspection images in which the background regions have the same color and the figures have different colors. A visual characteristic test image set according to any one of claims 1 to 3.

5. The inspection images include a plurality of inspection images in which the background regions have different colors from each other. A visual characteristic test image set according to any one of claims 1 to 3.

6. The inspection images include a plurality of inspection images in which the size of any one of the R component, G component, and B component of the figure is different from each other.

6. A visual characteristic test image set according to claim 5.

7. In each of the plurality of inspection images, the magnitudes of any two of the R component, G component, and B component are the same. A visual characteristic test image set according to claim 5 or claim 6.

8. the background region is achromatic; A visual characteristic test image set according to any one of claims 1 to 7.

9. the test area is arranged so that, when the subject looks at approximately the center of the test image, light emitted from the test area forms an image within a range of 2 degrees from the center of the subject's retina. A visual property test image set according to any one of claims 1 to 8.

10. A method for testing visual characteristics of a subject using a test image included in the test image set according to any one of claims 1 to 9, comprising: The visual characteristic inspection method includes: a presenting step of sequentially presenting the test images included in the test image set to the subject; a determining step of determining whether or not a predetermined test condition is satisfied when the subject views the test image presented in the presenting step; identifying an inspection image from the set of inspection images that satisfies the predetermined inspection conditions; A method for inspecting visual characteristics, including:

11. the predetermined inspection conditions include a first inspection condition that is a condition under which the subject can recognize the figure provided in the inspection area of the inspection image when the subject views the inspection image; The visual characteristics testing method according to claim 10.

12. the first test condition is a condition under which the subject can recognize the figure provided in the test area when viewing the test image without feeling dazzled by the test image; The visual characteristics testing method according to claim 11.

13. In the identifying step, if there are a plurality of inspection images that satisfy the first inspection condition among the plurality of inspection images, one of the plurality of inspection images that satisfies the first inspection condition is identified. The visual characteristics inspection method according to claim 11 or 12.

14. In the identifying step, the inspection image including the background region having a luminance value that is equal to or closest to the median value of the luminances of the plurality of the background regions of the plurality of the inspection images that satisfy the first inspection condition is identified. The visual characteristics testing method according to claim 13.

15. In the identifying step, the inspection image having the highest luminance in the background region is identified from among the plurality of inspection images that satisfy the first inspection condition. The visual characteristics testing method according to claim 13.

16. the predetermined inspection conditions include a second inspection condition under which the subject can recognize a difference in color between the background region and the figure when viewing the inspection image. The visual characteristic inspection method according to any one of claims 10 to 15.

17. the second inspection condition is a condition that, when the subject views the inspection image, the subject can recognize a difference in color between the background area and the figure, and can also recognize the figure provided in the inspection area. The visual characteristics testing method according to claim 16.

18. In the identifying step, if there are a plurality of inspection images that satisfy the second inspection condition, an inspection image in which the color of the background region and the color of the figure are closest to each other is identified from among the plurality of inspection images that satisfy the second inspection condition. The visual characteristics inspection method according to claim 16 or 17.

19. 1. A method for testing visual characteristics of a subject using a test image set including a plurality of test images, comprising: Each of the plurality of inspection images includes: A background region; an inspection area provided within the background area; and The plurality of inspection images are a plurality of red test images in which figures having different R components in RGB color space from the color of the background region are provided within the test region, the R components of the figures in the plurality of red test images being different from one another; a plurality of green test images in which figures having different G components in an RGB color space from the color of the background region are provided within the test region, the G components of the figures in the plurality of green test images being different from one another; Including, The visual characteristic inspection method includes: a red test image presenting step of sequentially presenting the plurality of red test images to the subject; a red test image determining step of determining whether the red test image presented in the red test image presenting step satisfies a predetermined test condition when the subject views the red test image; a red inspection image identifying step of identifying a red inspection image that satisfies the predetermined inspection condition from among the plurality of red inspection images; a green test image presenting step of sequentially presenting the plurality of green test images to the subject; a green test image judging step for judging whether the green test image presented to the subject in the green test image presenting step satisfies a predetermined test condition when the subject views the green test image; a green test image identifying step of identifying a green test image that satisfies the predetermined test condition from among the plurality of green test images; a determining step of determining a ratio of the subject's sensitivity to red light to that to green light based on the R component of the figure in the red test image identified in the red test image identifying step and the G component of the figure in the green test image identified in the green test image identifying step; A method for inspecting visual characteristics, including:

20. A method for inspecting visual characteristics according to any one of claims 10 to 19, comprising a determination step of determining the transmittance of a correction filter that adjusts the intensity of transmitted light based on the color of the inspection image that satisfies the predetermined inspection condition; 2. A method for determining characteristics of a correction filter, comprising:

21. A visual characteristic inspection method according to any one of claims 11 to 15, comprising a determination step of determining the transmittance of a predetermined wavelength band of a correction filter that adjusts the intensity of transmitted light based on the color of the background area of the inspection image that satisfies the first inspection condition, the higher the luminance of the background region of the inspection image that satisfies the first inspection condition, the higher the transmittance determined in the determining step. A method for determining the characteristics of a correction filter.

22. A visual characteristic inspection method according to any one of claims 16 to 18, comprising a determination step of determining the transmittance of a predetermined wavelength band of a correction filter that adjusts the intensity of transmitted light based on the color of the background area of the inspection image that satisfies the second inspection condition, In the inspection image that satisfies the second inspection condition, the closer the size of the predetermined color component of the background region and the size of the predetermined color component of the figure are, the higher the transmittance determined in the determining step. A method for determining the characteristics of a correction filter.

23. The transmittance is determined by the correction filter characteristic determination method according to any one of claims 20 to 22. Correction filter.

24. The figure has a circular shape.

2. The visual characteristic test image set of claim 1.

Images