Metho and device for determining brightness range of visual field affecting pupil diameter of eye, and view angle thereof

Abstract

To provide a program and a device for clarifying a range of brightness in a visual field that affects a pupil diameter.SOLUTION: A screen 105 with different levels of brightness of a viewpoint and the periphery is shown to a user, a pupil diameter of the user is measured, and the reference brightness with the pupil diameter on the "reference brightness-basic pupil diameter" data as a basic pupil diameter is obtained. The size of a circle is obtained, in which average brightness of the brightness of a circle of the viewpoint and a circle of the brightness affecting a peripheral pupil diameter coincides with the reference brightness on the "reference brightness-basic pupil diameter" data. A diameter of a peripheral brightness circle in a visual recognition range affecting the pupil diameter of the user is obtained. A view angle 802 of the peripheral brightness circle affecting the pupil diameter of the user can be determined from a distance to a visible object and the diameter of the peripheral brightness circle.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a program and an apparatus for determining the range of luminance in a user's visual field that influences pupil diameter. [Background technology]

[0002] It is already known that pupil diameter expands when a person pays attention (Non-Patent Document 1), but pupil diameter is also affected by the luminance of the visual field. To remove the influence of luminance and extract a pupil diameter related only to attention level, the relationship between the user's specific reference luminance and basic pupil diameter is measured in advance, the luminance of the user's visual field when viewing content is measured, and the basic pupil diameter corresponding to the same reference luminance as the measured luminance is deleted. This removes the influence of luminance on the user's pupil diameter, and makes it possible to obtain a pupil diameter corresponding only to the attention level to the viewed object, thereby determining the user's attention level to the viewed object (Prior Patent Document 1, Prior Patent Document 2).

[0003] In addition to brightness, factors that affect pupil diameter include breathing and pulse. As a method for eliminating the influence of the user's breathing and pulse, as shown in Patent Document 3, since breathing and pulse are almost periodic movements, it is shown that the influence of breathing and pulse can be eliminated from changes in the user's pupil diameter by applying a moving average or a low pass filter with a frequency lower than the breathing cycle to the data on pupil diameter over time (Patent Document 3). [Prior art documents]

[0004] [Non-Patent Document 1] EHHess:Attitude and Pupil Size,Scientific American.46-54,(1965).

[0005] [Non-patent document 2] Ishimatsu, Kazuma, and Miura, Toshiaki: Effects of aging on functional visual field: Focusing on traffic safety (Osaka University Graduate School of Human Sciences Bulletin Vol. 28) (2002) [Patent Document 1] Patent No. 6651536 "Viewer emotion determination device and program for determining viewer emotion"

[0006] [Patent Document 2] Patent No. 5445981 "Device for determining viewer's emotion regarding visually recognized scenes"

[0007] [Patent Document 3] Patent Publication No. 2019-55161: "Method for eliminating the influence of breathing and pulse on pupil diameter changes, and viewer emotion determination device, viewer emotion determination system, and program based on pupil diameter changes due to stimuli" Summary of the Invention [Problem to be solved by the invention]

[0008] The pupil diameter of the eye is affected by the luminance of the object being viewed, but there was no method to clearly determine which range (width) of the visual field is affected by the luminance, and no luminance measurement device based on that method. [Means for solving the problem]

[0009] The pupil diameter becomes smaller when the luminance of the visual field is high, and becomes larger when the luminance is low. In this case, the luminance that affects the user's pupil diameter is considered to be the average luminance of the luminance of the viewpoint and a certain range of luminance around it.

[0010] The pupil diameter for each luminance differs for each user. Therefore, the basic pupil diameter for each user is measured in advance for a standard luminance on a plain screen (a screen with the same overall luminance) to create relationship data for "standard luminance - basic pupil diameter."

[0011] The user is shown a screen with different luminances for the viewpoint and surroundings as shown in Figure 1, and the user's pupil diameter is measured. The reference luminance is calculated based on the "reference luminance - basic pupil diameter" data, with the pupil diameter being the basic pupil diameter. The average luminance of the luminance of the gaze circle (temporarily called the "viewpoint circle") and the luminance circle that affects the peripheral pupil diameter (temporarily called the "peripheral luminance circle") is calculated by finding the size of the circle that matches the reference luminance in the "reference luminance - basic pupil diameter" data. This determines the diameter of the peripheral luminance circle of the visible range that affects the user's pupil diameter. As a result, the viewing angle of the peripheral luminance circle, which affects the pupil diameter of the user, is determined from the distance of the viewed object and the diameter of the peripheral luminance circle. The measurement angle of the luminance meter must also be adjusted to the viewing angle of the peripheral luminance circle, and the present invention relates to a luminance measurement device that can be adjusted to the viewing angle of the peripheral luminance circle. [Effects of the Invention]

[0012] The present invention allows for accurate measurement of luminance that affects the user's pupil diameter. [Brief explanation of the drawings]

[0013] [Figure 1] Basic screen configuration [Figure 2] The size of the viewing circle on the display at a viewing angle of 2 degrees [Figure 3] Specific figures for H=33cm [Figure 4] The combination of the luminance of the viewing circle (A) and its surroundings (B) on the display [Figure 5] Graph showing the relationship between pupil diameter Pn (basic pupil diameter) and plain screen luminance Ln (reference luminance) of the display [Figure 6] The screen with the viewing circle (A) and the peripheral luminance circle (C) that affects the user's pupil diameter [Figure 7] Conceptual diagram of finding the corresponding luminance (Y) from the pupil diameter (Pc) on the basic pupil diameter [Figure 8] How to calculate the luminance meter measurement angle (θ) [Figure 9] Functional configuration of measurement angle adjustment luminance device [Figure 10] Operation flow DETAILED DESCRIPTION OF THE INVENTION

[0014] The following explanation will be given using the diagram. The present invention is not limited to the embodiments described below, but also includes appropriate modifications of the embodiments below within the scope obvious to those skilled in the art. As shown in Figure 1, the viewpoint is placed at the center of the display, and a basic screen is prepared with the brightness (luminance) of the field of view of the viewpoint (A) and the brightness of the area around it (B).

[0015] There are papers and information that generally state that the field of view of the “A” viewpoint circle is 2 degrees. In other words, when humans see something, the part of the eye that is completely visible is the "center" of the eye, a circle within a 2-degree range at the center of the visual field (the viewing circle) (Non-Patent Document 2, etc.) (Figure 2). In reality, the viewing angle of this viewing circle varies slightly depending on the person and the situation. Therefore, this viewing angle does not have to be 2°, and its determination method will follow other research. However, since most papers and documents state that the viewing angle of the viewing circle is 2°, from here on, we will treat the viewing angle of the viewing circle as 2°.

[0016] The size of the viewpoint circle is as follows: H×Tan 1°=R1(radius of viewpoint circle)----------------(Equation 1) R1×2=D1(viewpoint circle diameter)--------------------(Equation 2) For example, the KIKU-NAC device is designed to allow users to view a screen at a distance of 33 cm. So, when H=33cm (Fig. 3) 33(cm) x Tan 1° = 0.576(cm) (radius of the viewing circle) 0.576×2=1.15(cm) (viewpoint diameter)

[0017] The area of the viewpoint circle Sa is Sa=πR1 2 ---------------------------(Formula 3) For example, the KIKU-NAC device is a device that allows users to view a screen at a distance of 33 cm (H). Since R=0.578 Sa=π×0.576 2 =1.042cm 2

[0018] The brightness combinations for the display are as follows: the brightness of the viewpoint circle "A" in the center of the display in Figure 4 is changed in five steps from 0% to 100%, and for each brightness (luminance) of the viewpoint circle "A", the brightness of "B" around the viewpoint is changed in five steps from 0% to 100%. The combination is shown in Figure 4. Also, instead of changing the brightness (luminance) of "B" stepwise as in Figure 4, it is possible to change the brightness continuously.

[0019] To measure, the brightness of the display is changed as shown in Figure 4, and the user is asked to look at it, and the pupil diameter is measured. The pupil diameter when each user views a combination of the luminance La of the viewpoint and the luminance Lb of the surroundings is defined as Pb (1 to 25).

[0020] Screens 1, 7, 13, 19, and 25 in the table have the same viewpoint luminance and surrounding luminance, so they are plain screens and are standard luminance screens. Therefore, this pupil diameter is the basic pupil diameter, and the graph in Figure 5 shows the relationship between the reference luminance and the basic pupil diameter. The luminance of the reference screen of display 1 at 0% brightness is L1, 7 at 25% brightness = L2, 13 at 50% brightness = L3, 19 at 75% brightness = L4, and 25 at 100% brightness = L5. The corresponding user's basic pupil diameters are P1, P2, P3, P4, and P5, respectively.

[0021] The user's pupil diameter is measured for each combination of the luminance of viewpoint circle A and the luminance of surrounding circle B. As shown in Figure 6, the pupil diameter Pc is measured when the user looks at the viewing circle A. The area Sa of the circle of luminance La of the viewpoint circle A is Sa=πR1 2 -----------------------(Formula 4) When H=33cm, Sa is R1=0.576, so Sa=π×0.576 2 =1.042cm 2

[0022] Brightness of the surroundings B of the viewpoint Brightness of the surroundings Lb If the area of the peripheral luminance circle that affects the pupil diameter of the eye, including the area of the viewpoint circle Sa, is Sc, then Sc is the average luminance of the peripheral luminance circle "C" that includes the viewpoint circle "A." As shown in Figure 7, the reference luminance (Y) of the basic pupil diameter equivalent to the measured pupil diameter Pc is the average luminance of the peripheral luminance circle "C" that corresponds to the pupil diameter Pc. To find Y from the "reference luminance - basic pupil diameter" data, the corresponding luminance (Y) is calculated using proportional interpolation within the range of brightness corresponding to the measured Pc. As a specific example, in FIG. 7, when the measured pupil diameter is Pc, Pc is between the corresponding basic pupil diameters P2 and P3, and the corresponding brightness (luminance) is between L2 and L3. The following equation 6 holds true: TIFF2025120076000002.tif17139

[0023] Therefore, the luminance (Y) corresponding to the desired Pc is calculated by proportional distribution as shown in the following (Equation 6): TIFF2025120076000003.tif15134Y is the average luminance of the peripheral luminance circle, so the average of the total luminance (La × Sa + Lb × (Sc-Sa)) within the peripheral luminance circle "C" becomes the luminance (y). Therefore, the relational expression for the area Sc of the peripheral luminance circle "C" corresponding to the user's pupil diameter Pc is given by the following Equation 8. (La×Sa+Lb×(Sc-Sa)) / (Sa+(Sc-Sa))=Y (La×Sa+Lb×(Sc-Sa)) / Sc=Y ---------(Formula 7) Therefore, by solving equation 7, the area of Sc given the user's pupil diameter is: TIFF2025120076000004.tif15133

[0024] When searching for the corresponding luminance (Y) from the pupil diameter (Pc) in the "reference luminance - basic pupil diameter" data, the relationship between the reference luminance and basic pupil diameter can be approximated using the least squares method, etc. Y=f (Pc) It can be found from

[0025] The desired measurement angle of the luminance meter is assumed to be close to the user's eyes, The area Sc of the user's peripheral vision circle "C" on the display should be the same as the area measured by the luminance meter. Therefore, the measurement angle θ of the luminance meter should also be the same as the viewing angle of the peripheral vision circle "C."

[0026] In other words, the luminance meter measurement area (Sc) was calculated. The radius R of the circle Sc is the area Sc=πR 2 that's why TIFF2025120076000005.tif14145As shown in Figure 8, the luminance meter measurement angle θ can be calculated as follows. Luminance meter measurement angle θ=2×Tan -1 (R / H)--------------(Formula 10) (Figure 8)

[0027] This operation is performed for 1 to 25, and the luminance measurement angle (θ) is calculated. In reality, if a user views one of the luminance combinations in Figure 4 for five seconds, for example, the pupil diameter will be in the process of changing as it adapts to light immediately after switching to each luminance combination screen, so consideration must be given to the time it takes to adapt to light, such as by omitting the unstable data from the first two seconds and using the average value of the measurement data from the remaining three seconds for analysis.

[0028] The above functional configuration is shown in Figure 9. The user is asked to view each combination of the viewpoint and the brightness around the viewpoint in Figure 4 using the basic screen configuration in Figure 1, and the combined brightness data (La, Lb) and pupil diameter (Pb) are sent to the receiving unit. The analysis unit sends the relationship data between the reference luminance on the plain screen and the user's specific basic pupil diameter to the storage unit and stores it. The luminance data and pupil diameter measurement values for other combined luminance screens are sent to the analysis unit, and the reference luminance-basic pupil diameter data stored in the storage unit is referenced to determine the reference luminance corresponding to the measured pupil diameter. The viewing angle of the peripheral luminance circle is calculated from this value, and the result is sent as viewing angle data, along with gaze data based on the viewpoint position, to the luminance meter, which then measures the luminance using the viewing angle as the measurement angle toward the gaze position.

[0029] The operation flow is shown in Figure 10. 1001 The user is asked to look at the basic screen in Figure 1 for each combination of the viewpoint and brightness around the viewpoint in Figure 4. 1002 Measure the user's pupil diameter 1003 sends the combined luminance data and pupil diameter data to the receiving unit, and the analysis unit sends the relationship between the reference luminance on the plain screen and the user's specific basic pupil diameter, "reference luminance-basic pupil diameter" data, to the storage unit and stores it. 1004 The luminance data and pupil diameter measurement value of other combined luminance screens of the plain screen are sent to the analysis unit, and the luminance (Lb) (= Y) equivalent to the pupil diameter (Pc) is calculated from the accumulated "reference luminance - basic pupil diameter" data (using an approximation formula such as interpolation or least squares method). 1005 Calculate the luminance screen area (Sc) that corresponds to the user's pupil diameter (Y). 1006 Calculate the radius (R) of a circle around Sc 1007 Calculate half the viewing angle (θ / 2) from the distance (H) between the user and the display and R 1008 When measuring the pupil diameter while the user is viewing the content, measure the measurement angle of the luminance meter as (θ).

[0030] Pupil diameter measuring devices already on the market are equipped with a viewpoint measurement function (for example, KIKU-NAC or EMI-9 from NAC Image Technology Co., Ltd.), and it is possible to attach a luminance meter to these devices. The luminance meter having the functions of the present invention is The device is equipped with a function to automatically track the center of the luminance meter according to the line of sight obtained by pupil diameter measurement. The measurement angle of the luminance meter may be automatically adjusted (by a program) to track the viewing angle of the peripheral luminance circle obtained by the present invention, or may be set to the average value of the viewing angle (θ). [Industrial Applicability]

[0031] The present invention allows for accurate measurement of luminance that affects the user's pupil diameter. [Explanation of symbols]

[0032] A Viewpoint Circle B. Periphery of the viewpoint circle C. Peripheral luminance circle including the viewing circle that affects pupil diameter 100 Basic screen configuration 101 Display 102 Viewpoint Brightness 103 Viewpoint brightness screen (circle) 104 Brightness around the viewpoint 105 Brightness screen around the viewpoint 200 Display size at 2 degrees of user viewing angle 201 User's Eyes 202 Display surface 203 User's viewing angle (2 degrees) 204 Half the user's field of view (1 degree) 205 Eye-to-display distance 206 H×tan1°=R1 (viewpoint radius) 207 R1×2=D1 (viewpoint diameter) 501 Reference luminance Ln 502 Basic pupil diameter Pn 503 Display Brightness 602 Peripheral luminance circle that affects the user's pupil diameter 701 Pupil diameter (Pc) Corresponding luminance (Y) equivalent to 702 Pc 800 How to calculate the luminance meter measurement angle (θ) 801 Luminance Meter 802 Viewing angle (θ) Radius of the display of 803 viewing angles (R)

Claims

1. The pupil diameter of the eye is affected by the luminance of the visual field, and when determining the range of luminance that affects the pupil diameter of the eye within the user's visual field, the average luminance of the luminance of the viewing circle and the luminance of the surrounding circles determines the pupil diameter of the user. In advance, on a plain screen (a screen with the same brightness throughout), the user's basic pupil diameter is measured relative to the screen brightness (reference brightness) of the standard plain screen, and relationship data of "reference brightness - basic pupil diameter" specific to the user is created. The user is shown a screen with different brightness levels at the viewpoint and the periphery, and the user's pupil diameter is measured. A reference luminance corresponding to the measured pupil diameter is determined from the relationship data of "reference luminance-basic pupil diameter" specific to the user, which is prepared in advance. Next, the size (radius) of the surrounding brightness circle can be calculated, where the average value of the brightness of the viewpoint circle and the brightness of the surrounding circle coincides with the reference brightness corresponding to the measured pupil diameter. The range of this peripheral circle can be said to be the range of luminance that affects the pupil diameter. Therefore, from the distance from the user's eye to the viewed object and the radius of the peripheral luminance circle, it is possible to determine the angle of view (viewing angle) of the user's eye of the user's peripheral luminance circle by trigonometry. The luminance meter, which is the visual target when measuring the user's pupil diameter, is located near the user's eyes, and the measurement angle of the luminance meter needs to be the same as the user's viewing angle. The present invention relates to a method and a program for calculating the viewing angle.

2. Pupil diameter measurement devices currently on the market also have a gaze measurement function (for example, KIKU-NAC or EMR-10, EMR-9 from NAC Image Technology Co., Ltd.), and it is possible to attach a luminance meter to these devices. The luminance meter having the function of the present invention described in claim 1 has the function of automatically tracking the center of the luminance meter to the user's line of sight, which is obtained at the same time as pupil diameter measurement and is directed toward the user's viewpoint.

2. A luminance meter device having a function of automatically adjusting the measurement angle of the luminance meter to the user's viewing angle as claimed in claim 1, or a luminance meter device capable of setting the viewing angle of the luminance meter to the average value of the user's viewing angle.

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