Lens control device, eyeglass lens device, eyeglasses, control method, program

Abstract

To allow lenses to exhibit their initial functions by preventing the line of vision of the wearer of the glasses from getting out of an acceptable range from the optical axis of the lenses when the wearer is looking at another direction through the lenses.SOLUTION: The present invention relates to a lens controller 10 for controlling an optical axis variable lens 3 for which optical parameter of at least one of the direction and the position of the optical axis can be changed. The controller has a controller 11 for controlling the optical axis variable lens to change at least one of the optical axis parameters on the basis of the result of detection by vision line direction detection units 21A and 21B for detecting the direction of the line of vision of a wearer.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a lens control device, a spectacle lens device, spectacles, a control method, and a program.

Background Art

[0002] Patent Document 1 discloses a spectacle lens device that electrically controls a variable focus lens such as an oil / water encapsulated lens and changes the focal length of the variable focus lens for the purpose of delaying the onset or progression of myopia. In this device, for a myopic wearer wearing a variable focus lens, the switching between the focal length in a focused state and the focal length corresponding to a plus power (+3D) (the focal length in an unfocused state) is performed at a frequency so high that the wearer cannot perceive it.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A wearer may change the line-of-sight direction during use of the spectacle lens device. For example, when the wearer changes the viewing object from a nearby object to a distant object (when switching from near vision to distant vision), the line-of-sight direction of the wearer is changed. Also, due to the convergence / divergence movement that occurs when the distance to the viewing object is changed, the wearer's both eyes move in different directions and the line-of-sight direction of each eye of the wearer is changed. In a conventional spectacle lens device, when the line-of-sight direction of the wearer is changed, the line of sight of the wearer deviates greatly from the optical axis of the lens beyond the allowable range, and there is a possibility that the original function of the lens cannot be exerted.

Means for Solving the Problems

[0005] To solve the above-mentioned problems, one aspect of the present invention is a lens control device for controlling a variable optical axis lens in which at least one of the optical axis parameters, the direction and position of the optical axis, can be changed, and is characterized by having a control unit that controls the variable optical axis lens so as to change the at least one of the optical axis parameters based on the detection result of a gaze direction detection unit that detects the direction of the wearer's gaze. In this control device, the variable optical axis lens is controlled based on the wearer's gaze direction detected by the gaze direction detection unit, and at least one of the optical axis parameters, namely the direction and position of the optical axis of the variable optical axis lens, can be changed. As a result, even if the wearer's gaze viewed through the variable optical axis lens changes, the direction and position of the optical axis of the variable optical axis lens are changed accordingly, preventing the wearer's gaze from deviating beyond an acceptable range from the optical axis of the variable optical axis lens. Consequently, even if the wearer's gaze changes, the variable optical axis lens can perform its intended function (such as correcting eye abnormalities including refractive errors like myopia, hyperopia, and astigmatism).

[0006] In the lens control device, the variable optical axis lens may be a shape-variable lens in which at least one of the optical axis parameters changes as the shape of the refractive surface changes. This control device allows control not only of the position and direction of the optical axis, but also of other lens parameters such as focal length.

[0007] Furthermore, in the lens control device, the shape-variable lens may be a liquid lens in which the interface between two types of liquids serves as the refractive surface, and the shape of the interface can be changed according to the applied voltage. This control device enables high-speed and highly flexible control not only of the optical axis position and direction, but also of other lens parameters such as focal length.

[0008] Furthermore, in the lens control device, the control unit may control the variable optical axis lens such that the focal length of the variable optical axis lens changes to a focal length corresponding to at least one of the optical axis parameters. In this control device, the focal length of the variable optical axis lens can be changed in accordance with a change in at least one of the optical axis parameters, namely the position and direction of the optical axis of the variable optical axis lens. As a result, even when the wearer performs convergence and divergence or changes in gaze that involve a change in distance to the object being viewed through the variable optical axis lens, the movement of the wearer's ciliary muscle, such as relaxation and contraction, is minimized, thereby suppressing discomfort and eye fatigue for the wearer.

[0009] Furthermore, in the lens control device, the control unit may control the variable optical axis lens such that at least one of the optical axis parameters changes while maintaining the focal length of the variable optical axis lens. This control device allows for the change of at least one of the position and direction of the optical axis of a variable optical lens without changing the focal length of the variable optical lens. As a result, when the wearer changes their line of sight without changing the distance to the object being viewed through the variable optical lens, the movement of the wearer's ciliary muscle, such as relaxation and contraction, is reduced, thereby suppressing discomfort and eye fatigue for the wearer.

[0010] Furthermore, the lens control device may include a setting change unit that changes the focal length of the variable optical axis lens when the wearer's line of sight is the reference direction. In this control device, the focal length of the variable optical axis lens when the wearer's line of sight is directed towards the reference direction can be changed, for example, according to how the wearer intends to use the variable optical axis lens, or it can be changed to match the wearer's refractive power (refractive power measured by an ophthalmologist, etc.; hereinafter referred to as "prescribed refractive power").

[0011] Another aspect of the present invention is a spectacle lens device comprising a spectacle lens in which at least one of the optical axis parameters, the direction and position of the optical axis, can be changed, and a lens control device for controlling the optical axis lens, wherein the device includes a gaze direction detection unit for detecting the direction of the wearer's gaze, and the lens control device is used as the lens control device. Examples of this spectacle lens device include those used as items worn by the wearer, such as eyeglasses. When this spectacle lens device is used as an item worn by the wearer, even if the wearer's line of sight changes during their daily life while wearing the item, the wearer's line of sight, as viewed through the variable optical axis lens, will not deviate from the optical axis of the variable optical axis lens beyond an acceptable range, thereby enabling the variable optical axis lens to perform its intended function. Furthermore, this spectacle lens device can also be used as a stationary device installed in, for example, an ophthalmologist's office. In such a stationary spectacle lens device, even if the wearer's line of sight changes while they are viewing a predetermined object through the variable optical axis lens, the wearer's line of sight will not deviate from the optical axis of the variable optical axis lens beyond an acceptable range, thereby enabling the variable optical axis lens to perform its intended function. Furthermore, the variable optical axis lens and the lens control device may be configured as separate units, provided that they are electrically connected to each other by wire or wireless means.

[0012] A further aspect of the present invention is a pair of eyeglasses comprising the eyeglass lens device, wherein the optical axis variable lens is held in an eyeglass frame. If the spectacle lens device is used as spectacle, as described above, even if the wearer's line of sight changes during their daily life while wearing the spectacle, the wearer's line of sight will not deviate from the optical axis of the optical axis of the optical axis beyond an acceptable range, thereby allowing the optical axis of the optical axis to perform its intended function. Furthermore, if it is spectacle, the lens control device can be configured within the spectacle frame that holds the optical axis of the optical axis, simplifying the connection configuration between the optical axis of the optical axis and the lens control device, thus enabling cost reduction.

[0013] Furthermore, yet another aspect of the present invention is a control method for controlling a variable optical axis lens in which at least one of the optical axis parameters, the direction and position of the optical axis, can be changed, characterized in that the control step is to control the variable optical axis lens such that the at least one of the optical axis parameters changes based on the detection result of a gaze direction detection unit that detects the direction of the wearer's gaze. In this control method, the variable optical axis lens is controlled based on the wearer's line of sight detected by the line of sight direction detection unit, and at least one of the optical axis parameters, namely the direction and position of the optical axis of the variable optical axis lens, can be changed. As a result, even if the wearer's line of sight viewed through the variable optical axis lens changes, the wearer's line of sight will not deviate from the optical axis of the variable optical axis lens by an amount exceeding an acceptable range, and the variable optical axis lens will be able to perform its intended function.

[0014] Furthermore, yet another aspect of the present invention is a program for operating a computer of a lens control device that controls a variable optical axis lens in which at least one of the optical axis parameters, the direction and position of the optical axis, can be changed, characterized in that the computer functions as a control means for controlling the variable optical axis lens such that the at least one of the optical axis parameters changes based on the detection result of a gaze direction detection unit that detects the direction of the wearer's gaze. According to this program, based on the line-of-sight direction of the wearer detected by the line-of-sight direction detection unit, the optical-axis variable lens is controlled to change at least one optical-axis parameter of the direction and position of the optical axis of the optical-axis variable lens. Thereby, even if the line of sight of the wearer visually recognized through the optical-axis variable lens is changed, it is suppressed that the line of sight of the wearer deviates from the optical axis of the optical-axis variable lens beyond the allowable range, and the original function of the optical-axis variable lens can be exhibited.

Effect of the Invention

[0015] According to the present invention, even if the line of sight of the wearer visually recognized through the lens (optical-axis variable lens) is changed, it is suppressed that the line of sight of the wearer deviates from the optical axis of the lens beyond the allowable range, and the original function of the lens can be exhibited.

Brief Description of the Drawings

[0016] [Figure 1] Front view schematically showing the configuration of glasses according to an embodiment. [Figure 2] Plan view schematically showing the configuration of the glasses. [Figure 3] Cross-sectional view showing a schematic configuration of a variable-focus lens in the glasses. [Figure 4] Plan view showing a schematic configuration of a variable-focus lens in the glasses. [Figure 5] Block diagram showing the configuration of a control device in the glasses. [Figure 6] Plan view schematically showing the configuration of a left-eye line-of-sight direction detection unit in the glasses. [Figure 7] Flowchart showing the flow of optical-axis parameter control in the present embodiment.

Mode for Carrying Out the Invention

[0017] Hereinafter, an embodiment in which the present invention is applied to glasses as a glasses lens device including a lens control device will be described. Furthermore, the eyeglass lens device to which the present invention can be applied is not limited to eyeglasses, but may also be other articles worn by the wearer (hereinafter referred to as "user"). In addition, the present invention is not limited to articles worn by the user, but can also be applied to stationary eyeglass lens devices installed in ophthalmology clinics, etc.

[0018] Figure 1 is a schematic front view showing the configuration of the eyeglasses 1 according to this embodiment, and Figure 2 is a schematic top view showing the configuration of the eyeglasses 1 according to this embodiment. The eyeglasses 1 in this embodiment include an eyeglass frame 2, a pair of left and right variable optical axis lenses 3, 3, and a control device 10 which acts as a lens control device for controlling the optical axis parameters of the variable optical axis lenses 3, 3. The optical axis parameters referred to here are at least one of the direction and position of the optical axis of the variable optical axis lenses 3, 3.

[0019] The eyeglass frame 2 comprises a bridge portion 4, a pair of left and right lens holders 6, 6, a nose rest portion 7, a pair of left and right endpieces 8, 8, and a pair of left and right temple portions 9, 9.

[0020] The bridge section 4 is a member that connects the left and right lens holding sections 6, 6 that hold the variable optical axis lenses 3, 3. The bridge section 4 extends in the left-right direction between the left and right armor sections 8, 8, and the armor sections 8, 8 are attached to both ends of the bridge section 4 in the left-right direction. Preferably, the bridge section 4 is equipped with a lens distance adjustment section that connects the lens holding sections 6 so that the lens holding sections 6 can move in the left-right direction, and can adjust the left-right distance D between the pair of left and right variable optical axis lenses 3, 3 held by the lens holding sections 6. The lens distance D can be defined, for example, by the distance between reference positions on the variable optical axis lenses 3, 3 (for example, the center positions of the variable optical axis lenses 3, 3). Here, the reference positions of the variable optical axis lenses 3, 3 are equal to, for example, the optical center positions of the variable optical axis lenses 3, 3, and the lens distance D is equal to the distance between the optical centers of each variable optical axis lens 3, 3.

[0021] The lens holding parts 6, 6 are members that hold the variable optical axis lenses 3, 3. In this embodiment, the lens holding part 6 comprises a lens holding part body 6a that holds the variable optical axis lens 3, and slide parts 6b, 6c provided on the lens holding part body 6a, and the slide parts 6b, 6c constitute the lens distance adjustment part. Specifically, the slide parts 6b, 6c are members that hold the lens holding part body 6a so that it can slide in the left-right direction relative to the bridge part 4. In this embodiment, the slide parts 6b, 6c are hollow members into which the bridge part 4 is inserted and attached to the bridge part 4 so that it can slide along the longitudinal direction of the bridge part 4.

[0022] By providing an interlens distance adjustment unit, the interlens distance D of the variable optical axis lenses 3,3 can be adjusted to match the user's interpupillary distance PD in a normal visual state. When the variable optical axis lenses 3,3 are smaller than ordinary spectacle lenses, as in this embodiment, it is beneficial to be able to adjust the interlens distance D of the variable optical axis lenses 3,3 for each user to match their interpupillary distance PD.

[0023] The nose rest portion 7 is held by the bridge portion 4 and is a component that contacts the user's nose when the user puts on the glasses 1 to position the glasses 1.

[0024] The endpieces 8,8 are members that connect the bridge portion 4 and the temple portions 9,9. In this embodiment, the endpieces 8,8 include a mounting portion 8a that is attached to the end of the bridge portion 4 and a hinge portion 8b that rotatably supports the temple portion 9.

[0025] The temples 9,9 are components that rest on the user's ears when the user wears the eyeglasses 1. In this embodiment, the left and right temples 9,9 are configured to be folded toward the center of the eyeglasses 1 in the left-right direction by the hinges 8b provided on the endpieces 8,8.

[0026] The variable optical axis lenses 3,3 in this embodiment are not limited in their configuration as long as they are variable optical axis lenses that have a function to change the optical axis parameter that can be electrically controlled. However, it is preferable that the variable optical axis lenses 3,3 are shape-variable lenses in which at least one of the optical axis parameters (hereinafter simply referred to as "optical axis parameter") changes as a result of a change in the shape of the refractive surface. With a shape-variable lens, not only the position and direction of the optical axis but also other lens parameters such as focal length can be controlled. Lenses in which the focal length can be electrically controlled are also called variable-focus lenses.

[0027] Among shape-variable lenses, liquid lenses (also called electrowetting devices, etc.) are preferred, as they use the interface between two liquids as a refractive surface and allow for the modification of optical axis parameters by electrically controlling the wettability of the liquids to change the shape of the interface. With liquid lenses, lens parameters, including the position and direction of the optical axis and focal length, can be controlled quickly and with a high degree of freedom.

[0028] The variable optical axis lenses 3,3 of this embodiment employ, for example, liquid lenses with a lens diameter of approximately 5 mm to 12 mm. Furthermore, by using larger variable optical axis lenses, the user's line of sight range that the variable optical axis lens can cover can be expanded, thereby improving user convenience.

[0029] Figure 3 is a cross-sectional view showing the schematic configuration of the variable optical axis lens 3 in this embodiment. Figure 4 is a plan view showing the schematic configuration of the variable optical axis lens 3 in this embodiment. As shown in Figure 3, the optical axis variable lens 3 of this embodiment has a configuration in which an insulating liquid 311 and a conductive liquid 312, which are in contact in an unmixed state at interface I, are sealed by an annular first electrode 301 and two transparent window members 303 and 304 that close the upper and lower ends of the first electrode 301. The insulating liquid 311 is, for example, an oily liquid, and the conductive liquid 312 is, for example, an aqueous liquid with relatively low conductivity. A voltage V0 is applied to the first electrode 301, but in this embodiment, since the annular first electrode 301 is grounded, V0 = 0V. Furthermore, the first electrode 301 is insulated from the sealed insulating liquid 311 and conductive liquid 312 by an insulating layer 301a.

[0030] Furthermore, in this embodiment, the variable optical axis lens 3 has multiple pairs of second electrodes 302A, 302B, ... arranged symmetrically with respect to the axis O of the first electrode 301. In this embodiment, as shown in Figure 4, four pairs of second electrodes 302A to 302H are arranged on a circle centered on axis O, providing a total of eight second electrodes 302A to 302H.

[0031] As shown in Figure 3, the second electrodes 302A to 302H are positioned in contact with the conductive liquid 312. When voltages VA to VH are applied to each of the second electrodes 302A to 302H, a potential difference is generated between each of the second electrodes 302A to 302H and the first electrode 301, and the electrowetting effect can displace the end Ia of the insulating liquid 311 (the end Ia of interface I) along the insulating layer portion 301b on the first electrode 301. As the end Ia of the insulating liquid 311 is displaced in this way, the shape of the insulating liquid 311 changes, and the curvature of interface I is altered. Therefore, by controlling the voltages VA to VH applied to the second electrodes 302A to 302H, the focal length of the optical axis variable lens 3, which uses interface I as a refractive surface, can be changed.

[0032] In particular, the variable optical axis lens 3 of this embodiment can deform the interface I, which is the refractive surface, into a diffuse lens (concave lens), a planar lens, or a condensing lens (convex lens) by controlling the voltage VA to VH applied to the second electrodes 302A to 302H. Therefore, the eyeglasses 1 of this embodiment can be used as eyeglasses for nearsighted users by setting the variable optical axis lens 3 to a diffuse lens (concave lens), and can be used as eyeglasses for farsighted users by setting the variable optical axis lens 3 to a condensing lens (convex lens).

[0033] The variable optical axis lens 3 of this embodiment can change the focal length within a range of -15D to +15D in diopter equivalent (reciprocal of focal length). By using a variable optical axis lens 3 with such a wide range of focal length variation, it is possible to accommodate users with low vision, such as those with amblyopia.

[0034] In this embodiment, by applying the same voltage to all second electrodes 302A to 302H, which are positioned symmetrically with respect to the axis O of the first electrode 301, the focal length can be changed while keeping the optical axis of the variable optical axis lens 3 aligned with the axis O of the first electrode 301. On the other hand, by applying different voltages to each of the second electrodes 302A to 302H, it is possible not only to change the focal length but also to shift or tilt the optical axis of the variable optical axis lens 3. In other words, the variable optical axis lens 3 in this embodiment can change either the position and direction of the optical axis, or both, by controlling the applied voltages VA to VH.

[0035] As shown in Figure 1, the control device 10 is installed together with the battery 20 in one of the left and right armor sections 8, 8 (the left armor section 8 in the figure). The control device 10 can control the position, direction, and focal length of the optical axis

[0036] Figure 5 is a block diagram showing the configuration of the control device 10 in this embodiment. The control device 10 in this embodiment comprises a main control unit 11, a voltage changing unit 12, and an operation unit 13. The control device 10 is connected to the second electrodes 302A to 302H of the optical axis variable lens 3, a battery 20 as a power source for supplying voltage, and gaze direction detection units 21A and 21B for detecting the user's gaze direction. In this embodiment, there are two gaze direction detection units 21A and 21B that detect the gaze direction of each of the user's eyes, but a configuration in which only a gaze direction detection unit that detects the gaze direction of one of the user's eyes is provided, or a configuration in which a gaze direction detection unit that detects a single gaze direction common to both of the user's eyes is provided may also be adopted.

[0037] The main control unit 11 is composed of, for example, a control board (computer) on which a CPU, RAM, ROM, etc. are mounted, and performs overall control of the eyeglasses 1, which is an eyeglass lens device, by executing a predetermined control program stored in the ROM. In particular, in this embodiment, the main control unit 11 functions as a control unit (control means) that controls the variable optical axis lens 3 so that the optical axis parameters of the variable optical axis lenses 3, 3 change based on the user's gaze direction (detection result) detected by the gaze direction detection unit.

[0038] The voltage changing unit 12, under the control of the main control unit 11, changes the voltage applied from the battery 20 to each of the second electrodes 302A to 302H of the optical axis variable lens 3. The voltage changing unit 12 can individually change the voltage applied to each of the second electrodes 302A to 302H. However, the voltage changing unit 12 may be capable of partially changing only a portion of the second electrodes 302A to 302H (for example, only one pair of second electrodes).

[0039] The operation unit 13, when operated by the user, outputs an operation signal indicating the user's operation to the main control unit 11. Examples of user operations accepted by the operation unit 13 include turning the power on and off, issuing execution instructions to the main control unit 11, and changing the control content of the main control unit 11. The operation unit 13 is composed of an operating device of a type suitable for the content of the user operation it accepts (such as mechanical or electrostatic touch buttons, or rotary operating devices such as dials). It is also possible to configure the system so that these user operations are unnecessary, in which case the operation unit 13 can be omitted.

[0040] The battery 20 functions as a power source for the control device 10 and outputs a voltage to supply to the second electrodes 302A to 302H of the optical axis variable lens 3. The battery 20 may be a primary battery or a secondary battery. It may also be equipped with a power generation function such as a solar panel.

[0041] The two gaze direction detection units 21A and 21B individually detect the gaze direction of the user's right and left eyes, respectively. While their configuration is not limited as long as they can detect gaze direction, it is preferable that they be configured to be placed on the eyeglass frame 2.

[0042] Figure 6 is a plan view showing the schematic configuration of the left eye line of sight direction detection unit 21B in this embodiment. Note that in Figure 6, for illustrative purposes, the eyeglass frame 2 is omitted from the illustration, and only the optical axis variable lens 3 for the left eye is shown. The left eye gaze direction detection unit 21B in this embodiment consists of a light source 211, a half mirror 212, a camera 213 as an imaging means, and an image processing unit 214. The configuration of the right eye gaze direction detection unit 21A is the same as that of the left eye gaze direction detection unit 21B, so its description is omitted.

[0043] The light source 211 and camera 213 of the left eye gaze direction detection unit 21B are mounted on the left temple portion 9 near the left end portion 8 of the eyeglass frame 2, as indicated by reference numeral 21B in Figure 2. On the other hand, the half mirror 212 of the left eye gaze direction detection unit 21B is positioned between the left eye E of the user wearing the eyeglasses 1 and the optical axis variable lens 3 for the left eye, as shown in Figure 6. The half mirror 212 is preferably integrated with the optical axis variable lens 3, but it may also be a separate component.

[0044] The half mirror 212 has the function of reflecting incident near-infrared light and transmitting visible light. As a result, the visible light L from the object being viewed, which enters through the variable optical axis lens 3, passes through the half mirror 212 and enters the user's eye E, as shown in Figure 6, allowing the user to view the object.

[0045] The light source 211 emits invisible light, such as near-infrared light L0. The light source 211 is positioned on the same side as the user's eye E, who is wearing the glasses 1, relative to the half mirror 212. The near-infrared light L0 emitted from the light source 211 is reflected by the half mirror 212 and incident on the user's eye E. The near-infrared light incident on the user's eye E is reflected by the user's eye E (cornea) and reaches the half mirror 212 again. The near-infrared light L1 reflected by the user's eye E is then reflected by the half mirror 212 and incident on the camera 213, which is positioned near the light source 211.

[0046] Camera 213 is an imaging means that captures an image of invisible light irradiated from light source 211, and in this embodiment, it is a near-infrared camera capable of capturing an image of near-infrared light. The camera 213 in this embodiment is equipped with a filter that blocks visible light, and can capture an image of near-infrared light L1 reflected by the user's eye E without interference from visible light. The image data captured by camera 213 is output to image processing unit 214.

[0047] The image processing unit 214 is composed of, for example, a control board (computer) on which a CPU, RAM, ROM, etc. are mounted, and by executing a predetermined gaze direction detection program stored in the ROM, it detects the gaze direction of the user's eye E based on the image data captured by the camera 213. Alternatively, the functions of the image processing unit 214 may be assigned to the main control unit 11 of the control device 10, and the image processing unit 214 may be omitted.

[0048] The near-infrared image, which is a non-visible light image captured by the camera 213, includes an image of the user's eye E. The image processing unit 214 detects the direction of the user's gaze from the image of the user's eye E output from the camera 213. There are no particular limitations on the method for detecting the direction of the eye E's gaze, but for example, since the image captured by the camera 213 includes bright spots of near-infrared light, one method is to utilize these bright spots. Specifically, since these bright spots appear at a fixed point on the eye E in the image, regardless of the direction of the eye E's gaze, these bright spots can be used as a reference position, and the direction of the eye E's gaze can be detected from the relative position of the pupil center of the eye E to this reference position. Note that the detection of bright spots and the pupil center in the image output from the camera 213 can be achieved using existing image processing techniques such as edge extraction and Hough transform.

[0049] Next, an example of optical axis parameter control for the variable optical axis lenses 3,3 in this embodiment will be described. Figure 7 is a flowchart showing the flow of optical axis parameter control in this embodiment. In the optical axis parameter control of this embodiment, the main control unit 11, which executes a predetermined control program, controls the voltage change unit 12 to control the left and right variable optical axis lenses 3, 3 so that the direction of the optical axis, which is an optical axis parameter, changes, based on the detection results of the gaze direction detection units 21A and 21B (detection results of the gaze directions of the user's right and left eyes). Although the control of the two variable optical axis lenses 3, 3 corresponding to the user's right and left eyes is performed independently, the control content is the same, so the left and right variable optical axis lenses 3, 3 will not be distinguished below.

[0050] In this embodiment, when the operation unit 13 receives a power-on operation from the user (S1), first, if the setting of the basic focal length of the variable optical axis lens 3 has not been completed, the basic focal length is set (S2). In this embodiment, the variable optical axis lens 3 is controlled so that even if the optical axis direction of the variable optical axis lens 3 changes, the focal length of the variable optical axis lens 3 remains unchanged at the basic focal length. Note that here, optical axis parameter control is started when the power is turned on, but this is not limited to this, for example, a fitting detection unit that detects when the glasses 1 are put on by the user may be provided, and the optical axis parameter control may be started when it is detected that the user has put on the glasses 1.

[0051] The basic focal length can be set arbitrarily according to the user's intended use of the glasses 1 (the distance at which the user views objects). For example, when the user uses the glasses 1 to view nearby objects (smartphones, tablets, game consoles, books, etc.), the basic focal length is set to the focal length that brings these nearby objects into focus. Conversely, when the user uses the glasses 1 to view distant objects (videos from distant locations (movies, etc.), works of art or other objects to be appreciated, scenery, etc.), the basic focal length is set to the focal length that brings these distant objects into focus.

[0052] Furthermore, the basic focal length may be set to a fixed focal length for each user, regardless of how the user intends to use the glasses. For example, for a user with an eye abnormality including refractive errors such as myopia, hyperopia, or astigmatism, the basic focal length can be set to the focal length corresponding to the user's prescribed refractive power (basic refractive power). In this case, for example, for a myopic user, the focal length corresponding to negative refractive power would be set as the basic focal length.

[0053] The basic focal length can be set by a professional operator or the user themselves by operating the control unit 13. For example, if the control unit 13 is equipped with a dial indicating the refractive power, the basic focal length can be set by turning the dial to match the user's prescribed refractive power. In this case, an electrical signal (operation signal) corresponding to the rotation position of the dial is sent to the main control unit 11, and the main control unit 11 controls the voltage change unit 12 so that a voltage corresponding to this signal is applied to the second electrodes 302A to 302H of the variable optical lens 3. As a result, the curvature of the interface I between the insulating liquid 311 and the conductive liquid 312 in the variable optical lens 3 is changed due to a change in the shape of the interface I, and the focal length of the variable optical lens 3 is changed to the set basic focal length.

[0054] Once the basic focal length of the variable optical lens 3 has been set, the main control unit 11 starts the detection operation by the gaze direction detection units 21A and 21B (S3). As a result, near-infrared light L0 emitted from the light source 211 is reflected by the half mirror 212 and incident on each of the user's eyes E, and the reflected light is reflected again by the half mirror 212 and incident on each camera 213, capturing an image of each eye E. The image data of each eye E captured by each camera 213 is then processed by the respective image processing unit 214, and the gaze direction of each eye E is detected from the image of each eye E. This gaze direction detection operation is repeated at predetermined sampling intervals.

[0055] The detection results of the gaze direction of each eye E detected by the gaze direction detection units 21A and 21B are sent to the main control unit 11. The main control unit 11 controls the voltage change unit 12 and performs control to apply voltages corresponding to the gaze direction detection results to each of the second electrodes 302A to 302H of the optical axis variable lens 3 (S4). As a result, when the user's gaze direction changes, the voltage applied to each of the second electrodes 302A to 302H of the optical axis variable lens 3 is changed by the voltage change unit 12 according to the detection result, and the direction of the optical axis of the optical axis variable lens changes to follow the changed gaze direction of the user.

[0056] When the control unit 13 receives a power-off command from the user (Yes in S5), the main control unit 11 terminates the optical axis parameter control. At this time, the voltage supply to each of the second electrodes 302A to 302H of the variable optical axis lens 3 may be turned off or on. Turning off the voltage supply to each of the second electrodes 302A to 302H of the variable optical axis lens 3 can save power consumption of the battery 20.

[0057] On the other hand, if the voltage supply to each of the second electrodes 302A to 302H of the variable optical axis lens 3 is turned on, the optical axis parameter control, which changes the direction of the optical axis of the variable optical axis lens to follow the user's line of sight, is not performed, but the glasses 1 can be used as ordinary glasses. In this case, for example, when the operation unit 13 receives a power-off operation from the user, voltage is continuously applied to each of the second electrodes 302A to 302H so that the focal length of the variable optical axis lens 3 remains at the basic focal length and the optical axis of the variable optical axis lens 3 points in a predetermined reference direction.

[0058] According to this embodiment, even if the gaze of the user wearing the glasses 1 changes, the direction of the optical axis of the variable optical axis lenses 3,3 of the glasses 1 is changed accordingly, preventing the user's gaze from deviating too far from the optical axis of the variable optical axis lenses 3,3 beyond an acceptable range. As a result, even if the user's gaze changes, the original function of the variable optical axis lenses 3,3 (the function of correcting the user's eyes with the lenses) can be properly performed.

[0059] In particular, according to this embodiment, the direction of the optical axis of the variable optical axis lenses 3,3 changes while maintaining the focal length of the variable optical axis lenses 3,3. Therefore, when the user changes their line of sight without changing the distance to the object being viewed through the variable optical axis lenses 3,3, there is less movement such as relaxation and contraction of the ciliary muscle of the user's eye, which suppresses discomfort and eye fatigue for the user.

[0060] However, in this embodiment, the focal length of the variable optical axis lenses 3,3 may be controlled so that the focal length of the variable optical axis lenses 3,3 changes according to the detection result of the user's line of sight direction, corresponding to the focal length of the optical axis of the variable optical axis lenses 3,3. In this case, for example, table data describing the correspondence between the user's line of sight direction and the focal length of the variable optical axis lenses 3,3 is stored in the storage unit. The main control unit 11 then controls the voltage change unit 12 so that, based on the detection result of the user's line of sight direction, the direction of the optical axis of the variable optical axis lenses 3,3 is changed to follow the user's line of sight direction, and the focal length of the variable optical axis lenses 3,3 is also changed by reading the focal length corresponding to the changed optical axis direction from the storage unit.

[0061] According to this, for example, when a user changes their line of sight along with a change in distance to the object being viewed through the variable optical axis lenses 3,3, such as when changing from a near object to a far object (switching from near vision to far vision) or vice versa, the focal length of the variable optical axis lenses 3,3 can be automatically adjusted according to the change in distance to the object. Therefore, even when changing the line of sight along with a change in distance to the object, the movement of the user's ciliary muscles, such as relaxation and contraction, is reduced, suppressing discomfort and eye fatigue for the user.

[0062] In this embodiment, the optical axis parameter control was described in which the direction of the optical axis of the variable optical axis lens 3 is changed according to the detection result of the user's line of sight direction. However, a configuration in which the position of the optical axis of the variable optical axis lens 3 is changed is also possible. In this case, a configuration in which the position of the optical axis of the variable optical axis lens 3 is changed without changing the direction of the optical axis of the variable optical axis lens 3 is also possible, that is, a configuration in which the optical axis of the variable optical axis lens 3 is shifted in parallel.

[0063] Furthermore, the processing steps and components of the spectacle lens device such as the spectacle 1 described herein can be implemented by various means. For example, these steps and components may be implemented in hardware, firmware, software, or a combination thereof.

[0064] With respect to hardware implementation, the means such as processing units used to realize the processes and components described above may be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing units (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, computers, or combinations thereof.

[0065] Furthermore, with respect to the firmware and / or software implementation, means such as processing units used to realize the aforementioned components may be implemented with programs (e.g., code such as procedures, functions, modules, instructions, etc.) that perform the functions described herein. Generally, any computer / processor-readable medium that clearly embodies the firmware and / or software code may be used to implement means such as processing units used to realize the aforementioned processes and components as described herein. For example, the firmware and / or software code may be stored in memory in a control device, for example, and executed by a computer or processor. That memory may be implemented inside the computer or processor, or it may be implemented outside the processor. Also, the firmware and / or software code may be stored in a computer or processor-readable medium such as random access memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), programmable read-only memory (PROM), electrically erasable PROM (EEPROM), flash memory, floppy disks, compact disks (CDs), digital versatile disks (DVDs), magnetic or optical data storage devices, etc. The code may be executed by one or more computers or processors, and the computers or processors may be made to perform functional embodiments as described herein.

[0066] Furthermore, the medium may be a non-temporary recording medium. Also, the program code may be readable and executable by a computer, processor, or other device or machine, and its format is not limited to a specific format. For example, the program code may be source code, object code, or binary code, or it may be a mixture of two or more of these codes. [Explanation of Symbols]

[0067] 1: Glasses 2: Eyeglass frames 3: Variable optical axis lens 4: Bridge section 6: Lens holder 6a: Lens holder body 6b, 6c: Sliding part 7:Nose part 8: Armor section 8a: Mounting part 8b: Hinge section 9: Temple section 10: Control device 11: Main Control Unit 12: Voltage change section 13:Operation section 20: Battery 21A, 21B: Line of sight direction detection unit 211 :Light source 212: Half mirror 213: Camera 214: Image Processing Unit 301:First electrode 301a, 301b: Insulating layer 302A~302H: Second electrode 303,304: Window components 311: Insulating liquid 312: Conductive liquid D: Distance between lenses I: Interface Ia: End L: Visible light L0, L1: Near-infrared light O :Axis PD: pupillary distance

Claims

1. A lens control device for controlling a variable optical axis lens whose optical axis direction can be changed, The device includes a control unit that controls the variable optical axis lens so that the direction of the optical axis changes based on the detection result of a gaze direction detection unit that detects the direction of the wearer's gaze, The lens control device is characterized in that the optical axis variable lens is a liquid lens in which the interface between two types of liquids serves as the refractive surface, and the direction of the optical axis changes by changing the shape of the interface in accordance with the applied voltage.

2. In the lens control device according to claim 1, The lens control device is characterized in that the control unit controls the variable optical axis lens so that the focal length of the variable optical axis lens changes to a focal length corresponding to the direction of the optical axis.

3. In the lens control device according to claim 1, The lens control device is characterized in that the control unit controls the variable optical axis lens so that the direction of the optical axis changes while maintaining the focal length of the variable optical axis lens.

4. In the lens control device according to any one of claims 1 to 3, A lens control device characterized by having a setting change unit for setting and changing the focal length of the optical axis variable lens when the wearer's line of sight is in the reference direction.

5. A variable optical axis lens whose optical axis direction can be changed, An eyeglass lens device comprising a lens control device for controlling the optical axis variable lens, It is equipped with a gaze direction detection unit that detects the direction of the wearer's gaze, An eyeglass lens device characterized in that the lens control device is the lens control device described in any one of claims 1 to 4.

6. The eyeglass lens device is provided according to claim 5, Eyeglasses characterized in that the aforementioned variable optical axis lens is held in an eyeglass frame.

7. A control method for controlling a variable optical axis lens whose optical axis direction can be changed, The aforementioned variable optical axis lens is a liquid lens in which the direction of the optical axis changes by changing the shape of the interface between two types of liquids according to the applied voltage, with the interface serving as the refractive surface. A control method characterized by having a control step of controlling the variable optical axis lens so that the direction of the optical axis changes based on the detection result of a gaze direction detection unit that detects the direction of the wearer's gaze.

8. A program that enables the operation of a computer for a lens control device that controls a variable optical axis lens whose optical axis direction can be changed, The aforementioned variable optical axis lens is a liquid lens in which the direction of the optical axis changes by changing the shape of the interface between two types of liquids according to the applied voltage, with the interface serving as the refractive surface. A program characterized by causing the computer to function as a control means for controlling the variable optical axis lens so that the direction of the optical axis changes based on the detection result of a gaze direction detection unit that detects the direction of the wearer's gaze.

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