Automatic focusing eyeglasses and control method

Abstract

To provide automatic focusing eyeglasses and a control method that can adjust a focal length of a variable focus lens more accurately.SOLUTION: Automatic focusing eyeglasses 100 calculate a convergence distance based on a left eye gaze angle, a right eye gaze angle, and an interpupillary distance; calculate a first gaze distance as a distance in the same frontal direction as a convergence distance direction from a left eye EL to a target object M based on the left eye gaze angle and a first direction distance as a distance from the left eye EL to the target object M; calculate a second gaze distance as a frontal direction distance between a right eye ER and the target object M based on the right eye gaze angle and a second direction distance as a distance from the right eye ER to the target object M; determine a target object distance based on a convergence distance error range corresponding to the convergence distance, the first gaze distance, and the second gaze distance; and control a left variable focus lens 101 and a right variable focus lens 102 with an applied voltage or an applied current corresponding to the target object distance.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to autofocus eyeglasses and a control method. [Background technology]

[0002] Patent Document 1 describes multi-focal electronic eyeglasses that calculate a convergence distance based on a convergence angle and an interpupillary distance, and automatically adjust the focal length of a variable-focus lens based on the convergence distance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-262189 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, the convergence distance is calculated based on the convergence angle, so there may be a difference between the distance between the left eye variable focus lens and the object the user is gazing at, the distance between the right eye variable focus lens and the object, and the convergence distance. In this case, there is a problem that the focus of the user's eyes wearing the glasses does not match the object the user is gazing at.

[0005] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide automatic focus adjustment glasses and a control method that can adjust the focal length of a variable focus lens more accurately. [Means for solving the problem]

[0006] The automatic focus adjusting eyeglasses according to the present invention include a left variable focus lens and a right variable focus lens whose focal length changes depending on an applied voltage or an applied current, a left eye gaze measuring unit that detects the gaze of the left eye and measures the left eye gaze angle based on the detected gaze, a right eye gaze measuring unit that detects the gaze of the right eye and measures the right eye gaze angle based on the detected gaze, a left gaze point distance measuring unit that measures a first direction distance that is the distance from the left eye gaze measuring unit to an object, and a right gaze point distance measuring unit that measures a second direction distance that is the distance from the right eye gaze measuring unit to the object, a memory unit that stores a focal length table that associates an object distance used as the focal length with the applied voltage or the applied current and an error table that associates a convergence distance with a convergence distance error range that is an error range of the convergence distance, a calculation unit that determines the object distance, and and a focal length control unit that extracts the applied voltage or the applied current corresponding to the object distance from a point distance table and controls the left variable-focus lens and the right variable-focus lens with the applied voltage or the applied current, wherein the calculation unit calculates the convergence distance based on the left eye gaze angle, the right eye gaze angle, and the interpupillary distance, calculates a first gaze distance, which is the distance in the same front direction as the convergence distance direction between the left eye and the object, based on the left eye gaze angle and the first directional distance, calculates a second gaze distance, which is the distance in the front direction between the right eye and the object, based on the right eye gaze angle and the second directional distance, extracts the convergence distance error range corresponding to the convergence distance from the error table, and determines the object distance based on the convergence distance error range, the first gaze distance, and the second gaze distance.

[0007] In a control method according to the present invention, a computer controlling auto-focus adjusting glasses equipped with a left variable-focus lens and a right variable-focus lens whose focal length changes depending on an applied voltage or current detects the line of sight of a left eye, measures a left eye gaze angle based on the detected line of sight, detects the line of sight of a right eye, measures a right eye gaze angle based on the detected line of sight, measures a first directional distance which is a distance from the left eye to an object, measures a second directional distance which is a distance from the right eye to the object, calculates a convergence distance based on the left eye gaze angle and the right eye gaze angle and an interpupillary distance, and calculates a first gaze distance which is a distance in a front direction which is the same as the convergence distance direction between the left eye and the object based on the left eye gaze angle and the first directional distance. a second gaze distance, which is the distance in the front direction between the right eye and the object, calculated based on the right eye gaze angle and the second directional distance; a convergence distance error range corresponding to the convergence distance from an error table that corresponds the convergence distance to a convergence distance error range that is an error range of the convergence distance; a method for determining the object distance based on the convergence distance error range, the first gaze distance, and the second gaze distance; a method for extracting the applied voltage or the applied current corresponding to the object distance from a focal distance table that corresponds the object distance used as the focal distance to the applied voltage or the applied current; and controlling the left variable focus lens and the right variable focus lens with the applied voltage or the applied current. Effect of the Invention

[0008] According to the present invention, it is possible to provide automatic focus adjustment glasses and a control method that can adjust the focal length of a variable focus lens more accurately. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of auto-focus adjusting glasses according to a first embodiment. [Diagram 2] 2 is a block diagram showing an example of a control block of the auto-focus adjusting glasses according to the first embodiment. FIG. [Diagram 3] 4A to 4C are diagrams for explaining a method of calculating a convergence distance in the automatic focus adjusting glasses according to the first embodiment. [Figure 4] 4A to 4C are diagrams illustrating a method for calculating a first gaze distance and a second gaze distance in the auto focus adjustment eyeglasses according to the first embodiment. [Diagram 5] FIG. 4 is a diagram showing an example of an error table according to the first embodiment. [Figure 6] FIG. 4 is a diagram showing an example of a focal length table according to the first embodiment. [Figure 7] 4 is a flowchart showing an example of a control method according to the first embodiment. [Figure 8] FIG. 11 is a block diagram showing an example of a control block of the auto-focus adjusting glasses according to the second embodiment. [Figure 9] 11A to 11C are diagrams illustrating a correction method according to the second embodiment. [Figure 10] 11A to 11C are diagrams illustrating a correction method according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] EMBODIMENT 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an example of the configuration of auto-focus adjusting glasses 100 according to the first embodiment of the present invention. FIG. 2 shows an example of the control block of the auto-focus adjusting glasses 100. As shown in FIG. 1, the auto-focus adjusting glasses 100 include a left variable-focus lens 101, a right variable-focus lens 102, a glasses frame 103, a left eye gaze measuring unit 104, a right eye gaze measuring unit 105, a left gaze point distance measuring unit 106, a right gaze point distance measuring unit 107, a calculation unit 108, a storage unit 109, and a focal length control unit 110. In the auto-focus adjusting glasses 100, the calculation unit 108 determines the distance from the left variable-focus lens 101 and the right variable-focus lens 102 to an object (hereinafter referred to as "object distance") based on the measurement values ​​of the left eye gaze measuring unit 104, the right eye gaze measuring unit 105, the left gaze point distance measuring unit 106, and the right gaze point distance measuring unit 107. Here, the object is an object that a user wearing the auto-focus adjusting glasses 100 gazes at. Then, the focal length control unit 110 controls the left variable-focus lens 101 and the right variable-focus lens 102 with an applied voltage based on the determined object distance. This causes the auto-focus adjusting glasses 100 to function as multi-focal glasses. Note that the auto-focus adjusting glasses 100 may be capable of communicating with a mobile terminal owned by the user via a network, in which case the functions of the calculation unit 108 and the storage unit 109 may be realized by executing a predetermined app stored in the mobile terminal or the like.

[0011] The left variable-focus lens 101 and the right variable-focus lens 102 are liquid crystal lenses whose focal length changes as a result of a change in the refractive index of liquid crystal due to an applied voltage. In the first and second embodiments of the present invention, the left variable-focus lens 101 and the right variable-focus lens 102 are liquid crystal lenses, but the left variable-focus lens 101 and the right variable-focus lens 102 are not limited to liquid crystal lenses. The left variable-focus lens 101 and the right variable-focus lens 102 may be other types of lenses whose focal length changes due to an applied voltage or current. For example, the left variable-focus lens 101 and the right variable-focus lens 102 may be lenses made of an elastic polymer film or the like in which an optical liquid is sealed, and whose refractive index changes as the shape of the lens is deformed by an actuator. The left variable-focus lens 101 and the right variable-focus lens 102 may also be liquid lenses whose refractive index changes as the interface shape of immiscible liquids sealed in a predetermined container changes. The interface shape of the liquid lens changes, for example, when a voltage is applied to electrodes provided around the liquid lens. The interface shape of the liquid lens changes when an actuator provided around the liquid lens applies pressure to one of the liquids. The left variable-focus lens 101 and the right variable-focus lens 102 may be lenses formed by optically polishing an optically homogeneous single crystal, and the refractive index of the lenses may change when an electric field is applied.

[0012] The glasses frame 103 holds a left variable focus lens 101 and a right variable focus lens 102. The glasses frame 103 further holds a left eye gaze measuring unit 104, a right eye gaze measuring unit 105, a left gaze point distance measuring unit 106, a right gaze point distance measuring unit 107, and a focal length control unit 110. The glasses frame 103 may further hold a calculation unit 108 and a memory unit 109.

[0013] The left eye gaze measuring unit 104 detects the gaze of the left eye by a known method, and measures the left eye gaze angle based on the detected gaze. For example, the left eye gaze measuring unit 104 includes a camera that captures the left eye at a predetermined position of the eyeglass frame 103, and measures the left eye gaze angle by processing the image captured by the camera. Specifically, the left eye gaze measuring unit 104 detects the position of the pupil of the left eye from the image, and measures the left eye gaze angle based on the position of the pupil. Here, the left eye gaze angle is the angle between the front direction and the gaze direction of the left eye when the left eye is looking at an object. Here, the front direction is the direction perpendicular to the straight line connecting the center of the left eye and the center of the right eye.

[0014] The right eye gaze measuring unit 105 detects the gaze of the right eye by the same method as the left eye gaze measuring unit 104, and measures the right eye gaze angle based on the detected gaze. Here, the right eye gaze angle is the angle between the front direction and the gaze direction of the right eye when the right eye is looking at an object.

[0015] The left gaze point distance measurement unit 106 measures the first direction distance, which is the distance from the left gaze point distance measurement unit 106 to the object. Specifically, the left gaze point distance measurement unit 106 includes a camera that captures an image in the direction from the auto focus adjustment glasses 100 to the object, and causes the camera to capture an image in the direction of the left gaze angle measured by the left eye gaze measurement unit 104. Then, the left gaze point distance measurement unit 106 measures the first direction distance by performing image processing on the image captured by the camera.

[0016] The right gaze point distance measuring unit 107 measures the second direction distance, which is the distance from the right gaze point distance measuring unit 107 to the object, by a method similar to that used by the left gaze point distance measuring unit 106.

[0017] The calculation unit 108 includes a convergence distance calculation unit 111 , a first gaze distance calculation unit 112 , a second gaze distance calculation unit 113 , an error range setting unit 114 , and an object distance determination unit 115 .

[0018] The convergence distance calculation unit 111 calculates the convergence distance based on the left eye gaze angle, the right eye gaze angle, and the interpupillary distance. Fig. 3 shows a method for calculating the convergence distance. As shown in Fig. 3, the left eye gaze measurement unit 104 measures the left gaze angle θL, and the right eye gaze measurement unit 105 measures the right gaze angle θR. In addition, the distance D between the center of the pupil of the left eye EL and the center of the pupil of the right eye ER (hereinafter referred to as "interpupillary distance D") is set in advance. Then, the convergence distance calculation unit 111 calculates the convergence distance L based on the left gaze angle θL, the right gaze angle θR, and the interpupillary distance D using the following formula (1). L=D / (tanθL+tanθR) ····(1) Here, the convergence distance L is a substantially minimum distance between the object M and a straight line connecting the pupils of the left eye EL and the right eye ER, as shown in FIG.

[0019] The first gaze distance calculation unit 112 calculates the first gaze distance based on the left eye gaze angle θL and the first direction distance. The second gaze distance calculation unit 113 calculates the second gaze distance based on the right eye gaze angle θR and the second direction distance. FIG. 4 shows a method for calculating the first gaze distance and the second gaze distance. The first gaze distance L1 is a distance in the front direction that is the same as the convergence distance L direction between the left eye EL and the object M. Similarly, the second gaze distance L2 is a distance in the front direction that is the same as the convergence distance L direction between the right eye ER and the object M. As described above, the left eye gaze angle θL and the right eye gaze angle θR are measured by the left eye gaze measurement unit 104 and the right eye gaze measurement unit 105. As shown in FIG. 4, the first direction distance r1 is measured by the left gaze point distance measurement unit 106, and the second direction distance r2 is measured by the right gaze point distance measurement unit 107. Then, the first gaze distance calculation unit 112 calculates the first gaze distance L1 based on the left eye gaze angle θL and the first direction distance r1 using the following formula (2). L1 = r1 × cosθL (2) Similarly, the second gaze distance calculation unit 113 calculates the second gaze distance L2 based on the right eye gaze angle θR and the second direction distance r2 using the following formula (3). L2 = r2 × cosθR (3)

[0020] The error range setting unit 114 sets a convergence distance error range, which is an error range corresponding to the convergence distance L, by referring to an error table 117 stored in the storage unit 109. FIG. 5 shows an example of the error table 117. As shown in FIG. 5, the error table 117 is a table in which the convergence distance 117A corresponds to the convergence distance error range 117B. The convergence distance error range is an error range calculated in advance based on the measurement errors of the left eye gaze angle θL and the right eye gaze angle θR and the convergence distance D. The error range setting unit 114 sets the convergence distance error range by extracting the convergence distance error range 117B corresponding to the convergence distance L calculated by the convergence distance calculation unit 111 from the error table 117.

[0021] The object distance determination unit 115 determines the object distance d based on the convergence distance error range corresponding to the convergence distance L, and the first gaze distance L1 and the second gaze distance L2. Specifically, when at least one of the first gaze distance L1 and the second gaze distance L2 is included in the convergence distance error range set by the error range setting unit 114, the object distance determination unit 115 determines the included first gaze distance L1 and second gaze distance L2 as the object distance d. In addition, when neither the first gaze distance L1 nor the second gaze distance L2 is included in the convergence distance error range set by the error range setting unit 114, the object distance determination unit 115 determines the convergence distance L as the object distance d. More specifically, for example, when the convergence distance L is 100 m, the error range setting unit 114 sets the convergence distance error range to 75 to 125 m with reference to the error table 117 shown in Fig. 5. In this case, when the first gaze distance L1 calculated by the first gaze distance calculation unit 112 is 110 m and the second gaze distance L2 calculated by the second gaze distance calculation unit 113 is 150 m, the first gaze distance L1 is within the convergence distance error range and the second gaze distance L2 is outside the convergence distance error range. In this case, the object distance determination unit 115 determines the first gaze distance L1 = 110 m as the object distance d. Also, when the convergence distance L is 10 m, the error range setting unit 114 sets the convergence distance error range to 8 to 12 m with reference to the error table 117 shown in Fig. 5. In this case, when the first gaze distance L1 calculated by the first gaze distance calculation unit 112 is 15 m and the second gaze distance L2 calculated by the second gaze distance calculation unit 113 is 18 m, the first gaze distance L1 and the second gaze distance L2 are outside the convergence distance error range. In this case, the object distance determination unit 115 determines the convergence distance L = 10 m as the object distance d.

[0022] In addition, when both the first gaze distance L1 and the second gaze distance L2 are included in the convergence distance error range, the object distance determination unit 115 determines the first gaze distance L1, the second gaze distance L2, or the average value of the first gaze distance L1 and the second gaze distance L2 as the object distance d. For example, when the convergence distance L is 50 m, the error range setting unit 114 sets the convergence distance error range to 45 to 55 m with reference to the error table 117 shown in Fig. 5. In this case, when the first gaze distance L1 calculated by the first gaze distance calculation unit 112 is 55 m and the second gaze distance L2 calculated by the second gaze distance calculation unit 113 is 51 m, the first gaze distance L1 and the second gaze distance L2 are within the convergence distance error range. In this case, the object distance determination unit 115 determines the object distance d to be one of the following: first gaze distance L1=55 m, second gaze distance L2=51 m, or the average value of the first gaze distance L1 and the second gaze distance L2=53 m. Note that, if a dominant eye is set in advance, and both the first gaze distance L1 and the second gaze distance L2 are included in the convergence distance error range, the object distance determination unit 115 may determine the gaze distance of the dominant eye as the object distance d. For example, if the dominant eye is the "right" eye, and both the first gaze distance L1 and the second gaze distance L2 are included in the convergence distance error range, the object distance determination unit 115 may determine the second gaze distance L2 as the object distance d.

[0023] The storage unit 109 stores an error table 117 and a focal length table 118. The error table 117 is as described above. FIG. 6 shows an example of the focal length table 118. As shown in FIG. 6, the focal length table 118 is a table that associates an object distance 118A with a voltage 118B applied to the variable-focus lens. In the case where the variable-focus lens is a lens whose focal length changes depending on an applied current, the focal length table 118 is a table that associates an object distance 118A with a current applied to the variable-focus lens.

[0024] The focal length control unit 110 extracts an applied voltage 118B corresponding to the object distance d from the focal length table 118, and controls the left variable-focus lens 101 and the right variable-focus lens 102 with the applied voltage. Specifically, the focal length control unit 110 extracts an applied voltage 118B corresponding to the object distance d determined by the object distance determination unit 115 from the focal length table 118, and applies the applied voltage 118B to the left variable-focus lens 101 and the right variable-focus lens 102.

[0025] Next, a control method for the auto-focus adjusting glasses 100 according to the first embodiment will be described with reference to FIG. First, the left eye gaze measuring unit 104 detects the gaze of the left eye, and measures the left eye gaze angle θL based on the detected gaze (step S101).

[0026] Next, the left gaze point distance measuring unit 106 measures the first direction distance r1 (step S102).

[0027] Next, the first gaze distance calculation unit 112 of the calculation unit 108 calculates the first gaze distance L1 based on the left eye gaze angle θL and the first direction distance r1 (Step S103).

[0028] Next, the right eye gaze measuring unit 105 detects the gaze of the right eye, and measures the right eye gaze angle θR based on the detected gaze (step S104).

[0029] Next, the right gaze point distance measuring unit 107 measures the second direction distance r2 (step S105).

[0030] Next, the second gaze distance calculation unit 113 of the calculation unit 108 calculates the second gaze distance L2 based on the right eye gaze angle θR and the second direction distance r2 (Step S106).

[0031] The process of step S101 and the process of step S104 may be performed simultaneously or in sequence. Similarly, the process of step S102 and the process of step S105 may be performed simultaneously or in sequence. Moreover, the process of step S103 and the process of step S106 may be performed simultaneously or in sequence.

[0032] Next, the convergence distance calculation unit 111 of the calculation unit 108 calculates the convergence distance L based on the left eye gaze angle θL, the right eye gaze angle θR, and the interpupillary distance D (step S107).

[0033] Next, the error range setting unit 114 of the calculation unit 108 refers to the error table 117 stored in the storage unit 109, and sets a convergence distance error range corresponding to the convergence distance L calculated in step S107 (step S108).

[0034] Next, the object distance determination unit 115 of the calculation unit 108 determines the object distance d based on the convergence distance error range corresponding to the convergence distance L, the first gaze distance L1 and the second gaze distance L2 (step S109).

[0035] Next, the focal length control unit 110 extracts the applied voltage 118B corresponding to the object distance d from the focal length table 118 (step S110), applies the applied voltage to the left variable-focus lens 101 and the right variable-focus lens 102 (step S111), and ends this process.

[0036] According to the above-described automatic focus adjusting glasses 100 and control method according to the first embodiment, the object distance d is determined in consideration of not only the convergence distance L calculated based on only the left gaze angle θL and the right gaze angle θR, but also the first gaze distance L1 and the second gaze distance L2. In other words, the object distance d is determined in consideration of not only the convergence distance L calculated based on only the convergence angle, but also the distance L1 between the left variable-focus lens 101 and the object M and the distance L2 between the right variable-focus lens 102 and the object M. Specifically, a convergence distance error range is set according to the convergence distance L, and the object distance d is determined based on the convergence distance error range, the first gaze distance L1, and the second gaze distance L2. Therefore, even if a difference occurs between the convergence distance L and the first gaze distance L1 and the second gaze distance L2, the left variable-focus lens 101 and the right variable-focus lens 102 can be controlled with a suitable applied voltage. Therefore, the focal lengths of the left variable-focus lens 101 and the right variable-focus lens 102 can be adjusted more accurately.

[0037] Furthermore, when at least one of the first gaze distance L1 and the second gaze distance L2 is included in the convergence distance error range, the object distance determination unit 115 determines the included first gaze distance L1 and second gaze distance L2 as the object distance d. Furthermore, when neither the first gaze distance L1 nor the second gaze distance L2 is included in the convergence distance error range, the object distance determination unit 115 determines the convergence distance L as the object distance d. Furthermore, when both the first gaze distance L1 and the second gaze distance L2 are included in the convergence distance error range, the object distance determination unit 115 determines any one of the first gaze distance L1, the second gaze distance L2, or the average value of the first gaze distance L1 and the second gaze distance L2 as the object distance d. This makes it possible to more accurately determine the object distance d, and to more accurately adjust the focal lengths of the left variable-focus lens 101 and the right variable-focus lens 102.

[0038] Furthermore, when both the first gaze distance L1 and the second gaze distance L2 are included in the convergence distance error range, the object distance determination unit 115 may determine the gaze distance of the dominant eye as the object distance d. This allows the object distance d to be determined taking the dominant eye into consideration.

[0039] EMBODIMENT 2 Next, auto-focus adjustment glasses 200 according to a second embodiment of the present invention will be described. FIG. 8 shows an example of the configuration of the auto-focus adjustment glasses 200 according to the second embodiment. The auto-focus adjustment glasses 200 according to the second embodiment differ from the auto-focus adjustment glasses 100 according to the first embodiment in that the calculation unit 108 is provided with a correction unit 201. The auto-focus adjustment glasses 200 according to the second embodiment also differ from the auto-focus adjustment glasses 100 according to the first embodiment in that the storage unit 109 stores position information. Therefore, among the configuration of the auto-focus adjustment glasses 200 of the second embodiment, the same configuration as the auto-focus adjustment glasses 100 of the first embodiment is assigned the same reference numerals, and the description thereof will be omitted.

[0040] The auto-focus adjusting glasses 100 according to the first embodiment are based on the premise that the position of the left eye EL is the same as the position of the left gaze point distance measurement unit 106, and that the position of the right eye ER is the same as the position of the right gaze point distance measurement unit 107. The auto-focus adjusting glasses 200 according to the second embodiment are based on the premise that the position of the left eye EL is different from the position of the left gaze point distance measurement unit 106, and that the position of the right eye ER is different from the position of the right gaze point distance measurement unit 107, as shown in Fig. 9. Then, the correction unit 201 corrects the left eye gaze angle θL1 used by the left gaze point distance measurement unit 106 to measure the first direction distance r1 and the right eye gaze angle θR1 used by the right gaze point distance measurement unit 107 to measure the second direction distance r2.

[0041] The storage unit 109 stores position information 202 in addition to the error table 117 and the focal length table 118. The error table 117 and the focal length table 118 are as described above. The position information 202 is information on the positional relationship between the position of the left eye EL and the left gaze point distance measurement unit 106, and the position of the right eye ER and the right gaze point distance measurement unit 107. Specifically, the storage unit 109 stores, as the position information 202, a distance d1 between the position of the left eye EL and the left gaze point distance measurement unit 106 shown in FIG. 9, and a distance d2 between the position of the right eye ER and the right gaze point distance measurement unit 107. Note that the position of the left eye EL means the position of the center of the left eye EL, and the position of the right eye ER means the position of the center of the right eye ER. The distance d1 means the distance between the position of the center of the left eye EL and the position of the optical axis of the camera of the left gaze point distance measurement unit 106. Similarly, distance d2 means the distance between the position of the center of the right eye ER and the position of the optical axis of the camera of the right gaze point distance measuring unit 107. Moreover, the position of the left eye EL, the position of the right eye ER, the distance d1, and the distance d2 are values ​​measured in advance.

[0042] The correction unit 201 corrects the left eye gaze angle θL1 used by the left gaze point distance measurement unit 106 to measure the first direction distance r1 and the right eye gaze angle θR1 used by the right gaze point distance measurement unit 107 to measure the second direction distance r2 based on the position of the left eye EL and the position of the right eye ER and the position information 202. FIG. 9 and FIG. 10 show a correction method by the correction unit 201. Here, as shown in FIG. 9, the left eye gaze angle measured by the left eye gaze measurement unit 104 is θL1, the left eye gaze angle measured by the right eye gaze measurement unit 105 is θR1, and the convergence distance L is calculated using the above formula (1). In addition, the left measurement angle obtained by correcting the left eye gaze angle θL1 used by the left gaze point distance measurement unit 106 to measure the first direction distance r1 is θL2. Similarly, a right measurement angle obtained by correcting the right eye gaze angle θR1 used by the right gaze point distance measuring unit 107 to measure the second direction distance r2 is set to θR2.

[0043] As described above, the position of the left eye EL is different from the position of the left gaze point distance measurement unit 106, and the position of the right eye ER is different from the position of the right gaze point distance measurement unit 107. Therefore, as shown in the upper part of Fig. 10, even if the measurement direction of the left gaze point distance measurement unit 106 is tilted by the left gaze angle θL1, the object M cannot be imaged. Therefore, the left gaze point distance measurement unit 106 needs to tilt its measurement direction by the left measurement angle θL2. Therefore, the correction unit 201 calculates the left correction angle θL3 using the following formula (4) based on the distance d1 between the position of the left eye EL and the left gaze point distance measurement unit 106 and the convergence distance L, as shown in the lower part of Fig. 10. θL3=tan -1 (L / d1) (4) Then, the correction unit 201 calculates the left measured angle θL2 by using the following equation (5). θL2 = θL1 + θL3 (5) Similarly, the correction unit 201 calculates the right measured angle θR2.

[0044] Then, the left gaze point distance measurement unit 106 measures the first direction distance r1 from the image captured in the left measurement angle θL2 direction, and similarly, the right gaze point distance measurement unit 107 measures the second direction distance r2 from the image captured in the right measurement angle θR2 direction.

[0045] Furthermore, the first gaze distance calculation unit 112 calculates the first gaze distance L1 using the above formula (2) based on the left measurement angle θL2 and the first direction distance r1. Similarly, the second gaze distance calculation unit 113 calculates the second gaze distance L2 using the above formula (3) based on the right measurement angle θR2 and the second direction distance r2.

[0046] According to the automatic focusing glasses 200 and control method of embodiment 2 described above, even if the position of the left eye EL differs from the position of the left gaze point distance measurement unit 106 and the position of the right eye ER differs from the position of the right gaze point distance measurement unit 107, the object distance d can be accurately determined.

[0047] In the above embodiment, the present invention has been described as a hardware configuration, but the present invention is not limited to this. For example, the present invention can be realized by having a CPU execute a computer program to perform the above-mentioned processing procedure shown in FIG. 7 and the like.

[0048] The above-mentioned program can be stored and provided to a computer using various types of non-transitory computer readable media. The non-transitory computer readable medium includes various types of tangible storage media. Examples of the non-transitory computer readable medium include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), CD-ROM (Read Only Memory), CD-R, CD-R / W, and semiconductor memory (e.g., mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (Random Access Memory)). The program may be provided to a computer by various types of transitory computer readable media. Examples of the transitory computer readable medium include electric signals, optical signals, and electromagnetic waves. The transitory computer readable medium can provide the program to a computer via a wired communication path such as an electric wire and an optical fiber, or via a wireless communication path.

[0049] The present invention is not limited to the above-described embodiment, and can be modified as appropriate without departing from the spirit and scope of the present invention.

[0050] This disclosure includes matters that contribute to the realization of the SDGs "Good health and well-being for all" and contribute to value creation through healthcare products and services. [Explanation of symbols]

[0051] 100, 200 autofocus glasses 101 Left variable focus lens 102 Right variable focus lens 104 Left eye gaze measurement unit 105 Right eye gaze measurement unit 106 Left gaze point distance measurement unit 107 Right gaze point distance measurement unit 108 Arithmetic section 109 Storage section 110 Focal length control unit 111 Convergence distance calculation unit 112 First gaze distance calculation unit 113 Second gaze distance calculation unit 114 Error range setting section 115 Object distance determination unit 117 Error Table 118 Focal Length Table 201 Correction section 202 Location information EL left eye ER right eye M Object

Claims

1. a left variable-focus lens and a right variable-focus lens whose focal length changes depending on an applied voltage or current; a left eye gaze measuring unit that detects a gaze of a left eye and measures a left eye gaze angle based on the detected gaze; a right-eye gaze measuring unit that detects a gaze of a right eye and measures a right-eye gaze angle based on the detected gaze; a left gaze point distance measurement unit that measures a first direction distance that is a distance from the left eye gaze measurement unit to an object; a right gaze point distance measurement unit that measures a second direction distance that is a distance from the right eye gaze measurement unit to the object; a storage unit that stores a focal length table that associates an object distance used as the focal length with the applied voltage or the applied current, and an error table that associates a convergence distance with a convergence distance error range that is an error range of the convergence distance; A calculation unit for determining the object distance; a focal length control unit that extracts the applied voltage or the applied current corresponding to the object distance from the focal length table and controls the left variable-focus lens and the right variable-focus lens with the applied voltage or the applied current; Equipped with The calculation unit is calculating the convergence distance based on the left eye gaze angle, the right eye gaze angle, and an interpupillary distance; calculating a first gaze distance, which is a distance in a front direction that is the same as the convergence distance direction between the left eye and the object, based on the left eye gaze angle and the first directional distance; calculating a second gaze distance, which is a distance in the front direction between the right eye and the object, based on the right eye gaze angle and the second directional distance; extracting the convergence distance error range corresponding to the convergence distance from the error table; determining the object distance based on the convergence distance error range, the first gaze distance, and the second gaze distance; Autofocus glasses.

2. The calculation unit is When at least one of the first gaze distance and the second gaze distance is included in the convergence distance error range corresponding to the convergence distance, the included first gaze distance and the included second gaze distance are set as the object distance; When neither the first gaze distance nor the second gaze distance is included in the convergence distance error range corresponding to the convergence distance, the convergence distance is set as the object distance. The autofocus eyeglasses of claim 1 .

3. the storage unit stores position information that is information regarding a positional relationship between a left eye position and the left gaze point distance measurement unit, and a positional relationship between a right eye position and the right gaze point distance measurement unit; a correction unit that corrects the left eye gaze angle and the right eye gaze angle based on the position of the left eye and the position of the right eye and the position information, 3. The automatic focusing eyeglasses according to claim 1 or 2.

4. A computer controls automatic focusing glasses having a left variable focus lens and a right variable focus lens whose focal length changes depending on an applied voltage or an applied current, Detecting the line of sight of the left eye, measuring the line of sight angle of the left eye based on the detected line of sight, Detecting the line of sight of the right eye, and measuring the line of sight angle of the right eye based on the detected line of sight; measuring a first direction distance from the left eye to an object; measuring a second direction distance from the right eye to the object; calculating a convergence distance based on the left eye gaze angle, the right eye gaze angle, and an interpupillary distance; calculating a first gaze distance, which is a distance in a front direction that is the same as the convergence distance direction between the left eye and the object, based on the left eye gaze angle and the first directional distance; calculating a second gaze distance, which is a distance in the front direction between the right eye and the object, based on the right eye gaze angle and the second directional distance; extracting the convergence distance error range corresponding to the convergence distance from an error table in which the convergence distance and a convergence distance error range that is an error range of the convergence distance are associated with each other; determining the object distance based on the convergence distance error range, the first gaze distance, and the second gaze distance; extracting the applied voltage or the applied current corresponding to the object distance from a focal distance table in which the object distance used as the focal distance corresponds to the applied voltage or the applied current, and controlling the left variable-focus lens and the right variable-focus lens with the applied voltage or the applied current; Control methods.

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