Eyeglass device

Abstract

To realize an eyeglass device with which a diopter can be easily switched.SOLUTION: An eyeglass device (10) comprises: a polarizing element (31) into which external light enters, and which transmits light in a first polarized state or light in a second polarized state orthogonal to the first polarized state; and a converging / diverging unit (32) which is located in a stage following a first polarizing element, and which converges or diverges light entering from the polarizing element. The converging / diverging unit includes: a transforming element (33) capable of switching to convert the polarized state of light from one of the first polarized state and the second polarized state to the other of these, or to hold the polarized state of light; and a converging / diverging element (34) which is located in a stage following the transforming element, and which converges light in the first polarized state and diverges light in the second polarized state.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a spectacle device.

Background Art

[0002] There is known a technology of a multifocal spectacle having a first lens and a second lens whose focal length changes by applying a voltage, and repeatedly applying a plurality of voltage values to the second lens stepwise at a predetermined period (see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The above - mentioned technology is for realizing multifocal spectacles and is not intended to switch the power of the spectacles according to the change in the user's visual acuity.

[0005] One aspect of the present invention aims to realize a spectacle device capable of easily switching the power.

Means for Solving the Problems

[0006] In order to solve the above problems, a spectacle device according to an aspect of the present invention includes a polarizing element that allows external light to enter and transmits light in a first polarization state or light in a second polarization state orthogonal to the first polarization state, and a converging / diverging unit disposed downstream of the first polarizing element that converges or diverges the light incident from the polarizing element. The converging / diverging unit includes a conversion element capable of switching between converting the polarization state of light from one of the first polarization state and the second polarization state to the other or maintaining the polarization state of the light, and a converging / diverging element disposed downstream of the conversion element that converges the light in the first polarization state and diverges the light in the second polarization state.

Advantages of the Invention

[0007] According to an aspect of the present invention, it is possible to realize a spectacle device capable of easily switching diopters.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0009] 〔Embodiment 1〕 Hereinafter, an embodiment of the present invention will be described in detail. FIG. 1 is a perspective view showing a spectacle device 10 according to Embodiment 1 of the present invention. The spectacle device 10 includes a frame 20, a lens unit 30, and a control unit 40.

[0010] The frame 20 has a holding portion 21 that holds the lens unit 30, an ear pad 22 for hanging on the ears of the user (human), and a nose pad 23 for hanging on the nose of the user.

[0011] The lens unit 30 can be divided into lens units 30a and 30b corresponding to the left and right eyes of the user, respectively. The lens units 30a and 30b function as lenses that converge or diverge light from the outside world and make it incident on the user's eyes. The power (also referred to as "spectacle power") of the lens units 30a and 30b is switchable. Details of the lens units 30a and 30b will be described later.

[0012] This switching can be appropriately performed by the user. For example, the spectacle device 10 may include a switch unit for switching the power. The switch unit can be installed, for example, on the side of the frame 20 (as an example, at the position of the ear pad 22 or the position from the holding portion 21 to the ear pad 22). When the switch unit is arranged on the side of the frame 20, the operability of the user becomes good. That is, the user can operate the switch unit to switch the power while wearing the glasses and looking at an object.

[0013] Alternatively, the switching may be executable from an external device such as a mobile terminal (e.g., a smartphone). For example, the glasses device 10 may include a communication unit (e.g., Bluetooth (registered trademark), WiFi (registered trademark)) that can communicate with an external device such as a mobile terminal, and the user may operate the mobile terminal to switch the diopter.

[0014] Furthermore, the switch unit and the mobile terminal may be used in combination. For example, the mobile terminal may preset a plurality of diopters from the variable range of the diopter of the glasses device 10, and the switch unit may be able to switch the plurality of preset diopters in sequence. For example, -3.75 and 1.75 may be selected (set) as presets from the diopters shown in FIG. 6 described later, and the switch unit may alternately switch between -3.75 and 1.75. In this case, the diopter for both near and far vision selected on the mobile terminal will be switched by the switch unit of the glasses device 10. Note that both the setting of such preset diopters and the switching of the diopters may be executed on the mobile terminal.

[0015] The control unit 40 controls the operation of the glasses device 10, particularly the lens units 30a and 30b. The details of the control unit 40 will be described later.

[0016] FIG. 2 is a perspective view showing an example of the state where the user wears the glasses device. FIG. 3 is a view showing an enlarged part of FIG. 2.

[0017] Here, as shown in FIG. 3, the lens units 30a and 30b have a substantially rectangular outer shape with a width W and a height H. For example, the width W is 48 mm and the height H is 29 mm. The lens units 30a and 30b may be circular or elliptical in shape. The lens units 30a and 30b each have an optical axis Aoa, Aob and a geometric center Cga, Cgb.

[0018] The optical axes Aoa and Aob represent the central axes of light convergence and divergence in the lens units 30a and 30b respectively. When light converges, it passes through the focal point. The intersections of the optical axes Aoa and Aob with the lens units 30a and 30b are the optical centers Coa and Cob. The optical centers Coa and Cob are preferably located at positions, for example, about 2 / 5 of the outer shape of the lens units 30a and 30b. Here, the optical center Cob is arranged at a distance Dx from the inner side of the lens unit 30b and a distance Dy from the upper side of the lens unit 30b. For example, the distance Dx is 20 mm and the distance Dy is 12 mm.

[0019] The geometric centers Cga and Cgb represent the centers of the lens units 30a and 30b when viewed from the outside, and are the centers of the surface shapes of the lens units 30a and 30b when viewed from the outside.

[0020] The optical axes Aoa and Aob are generally set to correspond to the centers of the eyes (pupils) of the user (human). That is, the optical axes Aoa and Aob are set to correspond to the optical axes of a pair of human eyeballs. On the other hand, the geometric centers Cga and Cgb are generally set to be more outward on the left and right than the center of the user's eye (pupil). This is to enable the user to view a wider range to the left and right through the lens units 30a and 30b. As a result, as shown in Figure 2, the distance D0 between the pair of optical axes Aoa and Aob (or between the pair of optical centers Coa and Cob) is smaller than the distance D between the pair of geometric centers Cga and Cgb. If the distance D0 becomes greater than or equal to the distance D, the range in which the user can view to the left and right through the lens units 30a and 30b becomes narrower.

[0021] Note that the optical axes Aoa and Aob (optical centers Coa and Cob) are defined by the lens units 30a and 30b, particularly the convergence / divergence unit 32 described later (which constitutes the lens units 30a and 30b). Therefore, the (plural) convergence / divergence units 32 may have a pair of parts (corresponding to the lens units 30a and 30b) that respectively correspond to a pair of human eyes, and these pair of parts may each have an optical axis.

[0022] FIG. 4 is a schematic diagram showing a configuration example of the lens unit 30 (30a, 30b). The lens unit 30 receives light L1 from the outside world, converges or diverges this light L1, and makes it incident on the user's eye E as light L2. The user can clearly view an image of the outside world through the spectacle device 10 (lens unit 30) by the light being converged or diverged so as to correspond to his or her eyesight. The lens unit 30 (spectacle device 10) has a polarization element 31 and a converging / diverging unit 32.

[0023] The polarization element 31 is an element that receives external light and transmits light in a first polarization state or light in a second polarization state orthogonal to the first polarization state. The first and second polarization states are, for example, right circular polarization and left circular polarization. The polarization element 31 can be, for example, a circular polarizer (hereinafter also referred to as "pol"), that is, a right-handed circular polarizer (hereinafter also referred to as "R-pol") that passes right circular polarization, or a left-handed circular polarizer (hereinafter also referred to as "L-pol") that passes left circular polarization. The circular polarizer can be composed of, for example, a combination of a linear polarizer and a quarter-wave plate. By setting the angle formed by the axes of the linear polarizer and the quarter-wave plate, a right-handed circular polarizer or a left-handed circular polarizer can be obtained.

[0024] The converging / diverging unit 32 is arranged at the subsequent stage of the polarization element 31 and is an element that converges or diverges the light incident from the polarization element 31. The converging / diverging unit 32 has a conversion element 33 and a converging / diverging element 34.

[0025] The conversion element 33 is an element capable of switching between converting the polarization state of light from one of a first polarization state and a second polarization state to the other or maintaining the polarization state of light. The conversion element 33 can use a switchable half-wave plate (hereinafter also referred to as "sHWP") that can switch the applied phase difference between a half wavelength and a zero wavelength by applying a voltage. The conversion element 33 has two states: a transmission state (phase difference: zero) that allows right-circularly polarized light and left-circularly polarized light to pass through as they are, and an inversion state (phase difference: half wavelength) that converts right-circularly polarized light to left-circularly polarized light and left-circularly polarized light to right-circularly polarized light. For this reason, the spectacle device 10 has a voltage supply unit (not shown) that supplies a voltage to the conversion element 33. The voltage supply unit is controlled by the control unit 40 and can switch the state (transmission state, inversion state) of the conversion element 33.

[0026] This voltage supply unit may have a rechargeable battery. Thereby, connection between the spectacle device 10 and a power source by a power cable becomes unnecessary. As a result, a user's finger or the like is not caught by the power cable, and the worn spectacle device 10 does not come off from the user.

[0027] This battery may be disposed, for example, at any position on the lateral side of the frame 20 close to the lens unit 30. At this time, substantially the same weight of batteries may be installed on both the left and right sides of the frame 20. Thereby, the balance between the left and right of the spectacle device 10 is ensured, and the comfort of the user wearing the spectacle device 10 can be improved. Further, it is possible to prevent the spectacle device 10 from coming off from the user and falling due to the imbalance in weight between the left and right of the spectacle device 10.

[0028] The spectacle device 10 may include a connection terminal for a power cable. When the charge amount of the battery decreases, the power source and the spectacle device 10 can be connected by a power cable to charge the battery. Note that if wireless charging of the battery is possible as described later, the connection terminal for the power cable may not be provided.

[0029] The glasses device 10 may be provided with a wireless charging unit that enables wireless charging of the battery. Here, when the batteries are arranged on the left and right sides of the frame 20, the left and right batteries may be wirelessly charged at the same time by folding and overlapping the frame 20.

[0030] The converging / diverging element 34 is an element that is arranged downstream of the conversion element 33 and converges light in a first polarization state and diverges light in a second polarization state. As the converging / diverging element 34, a Pancharatnam-Berry lens (hereinafter, also referred to as a "PB lens") can be used. The PB lens can be made using a liquid crystal polymer. For example, (1) a pattern of an alignment film (alignment pattern) for aligning the molecules of the liquid crystal polymer is formed on a light-transmissive substrate, and (2) the liquid crystal polymer is applied on the pattern of the alignment film and cured by ultraviolet light (UV) or the like. In the PB lens, the liquid crystal molecules are arranged with periodicity in a plurality of circumferential directions having a common center. As a result, the PB lens functions as a polarization diffraction lens and can converge or diverge light.

[0031] In the present embodiment, the PB lens converges right circularly polarized light and diverges left circularly polarized light. More specifically, the PB lens emits the incident right circularly polarized light as left circularly polarized light that converges, and emits the incident left circularly polarized light as right circularly polarized light that diverges. Such a PB lens can be formed, for example, by the alignment pattern of the liquid crystal in the PB lens, one or both of the multilayering of the PB lens.

[0032] Hereinafter, as the converging / diverging element 34, a PB lens that "converges the incident right circularly polarized light and diverges the incident left circularly polarized light" will be described as an example. However, it is also possible to use a PB lens that "converges the incident left circularly polarized light and diverges the incident right circularly polarized light" as the converging / diverging element 34.

[0033] Here, when left circularly polarized light converging from the PB lens is emitted, the emitted light may include right circularly polarized light as a noise component. On the other hand, when right circularly polarized light diverging from the PB lens is emitted, the emitted light may include left circularly polarized light as a noise component. This noise component causes multiple images (ghosts) for the user. A method for eliminating this will be described in Embodiment 3.

[0034] The PB lens may have wavelength dependence of light. That is, since the PB lens utilizes the diffraction phenomenon of light, as the wavelength of light becomes longer, the focal length becomes smaller (the diffraction angle is larger), and as the wavelength of light becomes shorter, the focal length tends to become larger (the diffraction angle is smaller). That is, for the PB lens, as the wavelength of light becomes longer, the convergence / divergence of light becomes larger. This wavelength dependence causes chromatic aberration, that is, image bleeding due to color for the user. A method for eliminating this will be described in Embodiment 4.

[0035] The control unit 40 causes the powers of the lens units 30a and 30b to be switched. The control unit 40 switches the powers of the lens units 30a and 30b, for example, based on an input of information from the user. Specifically, the control unit 40 controls a voltage application unit that applies a voltage to the conversion element 33 to cause the state of the conversion element 33, and thus the powers of the lens units 30a and 30b, to be switched. The control unit 40 can control the state of the conversion element, for example, based on the user input and a table (see, for example, FIGS. 6, 8, and 11) showing the relationship between the total power and the state of the conversion element.

[0036] Here, assuming that the polarization element 31, the conversion element 33, and the converging / diverging element 34 are a left circularly polarized element (L-pol), an sHWP, and a PB lens, respectively, the operation of the spectacle device 10 will be described. The sHWP can be switched between a transmission state (phase difference: zero) that allows left circularly polarized light (and right circularly polarized light) to pass through as it is and an inversion state (phase difference: 1 / 2 wavelength) that converts left circularly polarized light to right polarized light and right circularly polarized light to left polarized light by the control unit 40.

[0037] When the sHWP is in the transmission state, the left circularly polarized light emitted from the L-pol is directly incident on the PB lens and diverged by the PB lens. On the other hand, when the sHWP is in the inverted state, the left circularly polarized light emitted from the L-pol is converted into right circularly polarized light, incident on the PB lens, and converged by the PB lens.

[0038] As described above, according to Embodiment 1, the control unit 40 can switch the state of the conversion element 33 to switch the convergence and divergence of light in the lens unit 30, and switch the spectacle device 10 between myopia use and hyperopia use (or presbyopia use).

[0039] 〔Embodiment 2〕 Embodiment 2 of the present invention will be described below. For convenience of explanation, members having the same functions as those described in the above embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.

[0040] FIG. 5 is a schematic diagram showing the lens unit 30 of the spectacle device 10 according to Embodiment 2 of the present invention. In Embodiment 2, the lens unit 30 includes n (n: an integer of 2 or more) convergence / divergence units 32 arranged in multiple stages. Here, as an example, the number n of the convergence / divergence units 32 is set to 4.

[0041] The n convergence / divergence units 32 can be switched between positive and negative spectacle powers by the control unit 40. The n convergence / divergence units 32 preferably have different spectacle powers from each other. For example, the n convergence / divergence units include one convergence / divergence unit 32 having the minimum spectacle power and the other "n - 1" convergence / divergence units each having a spectacle power corresponding to m (m: an integer, 1 ≤ m ≤ n - 1) times the minimum spectacle power. Here, the minimum spectacle power of the n convergence / divergence units may be, for example, 0.25 [D] or less. By setting the minimum spectacle power to 0.25 [D], it is possible to switch the power in steps of 0.5 [D] suitable for the human eye. m times (m: integer, 1 ≤ m ≤ n - 1) of the minimum spectacle power. Here, the minimum spectacle power of the n convergence / divergence units may be, for example, 0.25 [D] or less. By setting the minimum spectacle power to 0.25 [D], it is possible to switch the power in steps of 0.5 [D] suitable for the human eye.

[0042] FIG. 6 is a table showing an example of diopter switching in the spectacle device according to Embodiment 2 of the present invention. The control unit 40 can switch the positive and negative of the spectacle diopter in the converging / diverging units 32(1) to 32(4) of steps (1) to (4). In the converging / diverging unit 32(4) of step (4), the (minimum) spectacle diopter of 0.25 [D] can be switched between positive and negative. On the other hand, the conversion elements 33(3) to 33(1) can switch the positive and negative of the spectacle diopters of 0.5 [D], 1.0 [D], and 2.0 [D], which are 2 1 times, 2 2 times, and 2 3 times the minimum spectacle diopter of 0.25 [D]. Here, for the sake of clarity, the diopters are arranged in ascending order from steps (1) to (4), but this order can be changed as appropriate.

[0043] The control unit 40 switches the states (transmission state, inversion state) of the plurality of conversion elements 33 based on, for example, the table shown in FIG. 6, thereby switching the spectacle diopter of the spectacle device 10 (lens unit 30) in 2 n steps. Here, the diopter (total diopter) of the spectacle device 10 (lens unit 30) can be switched in 0.5 [D] increments within the range of -3.75 [D] to +3.75 [D]. As a result, it becomes easy to cope with various visual acuities from myopia to hyperopia (presbyopia).

[0044] As described above, according to Embodiment 2, the control unit 40 can switch the states (transmission state, inversion state) of the plurality of conversion elements 33 to switch the diopter (total diopter) in the lens unit 30 in multiple steps.

[0045] [Embodiment 3] Embodiment 3 of the present invention will be described below. For the sake of convenience of explanation, members having the same functions as those described in the above embodiments are denoted by the same reference numerals, and their descriptions will not be repeated.

[0046] FIG. 7 is a schematic diagram showing the lens unit 30 of the glasses device 10 according to Embodiment 3 of the present invention. Here, the glasses device 10 includes a polarization blocking unit 35(5) at the final stage (5). The polarization blocking unit 35(5) is disposed downstream of the plurality of converging / diverging units 32 and blocks light in the first polarization state or light in the second polarization state.

[0047] The polarization blocking unit 35 includes a second conversion element 33(5) and a second polarization element 31(5). The second conversion element 33(5) is an element capable of switching between converting the polarization state of light from one of the first polarization state and the second polarization state to the other or maintaining the polarization state of light, and may be the same as the conversion element 33 in the previous stage.

[0048] The second polarization element 31(5) is an element that blocks light in the first polarization state or light in the second polarization state included in the light emitted from the second conversion element 33(5), and may be the same as the polarization element 31 in the previous stage.

[0049] In the present embodiment, by providing the polarization blocking unit 35(5), it is possible to eliminate double images (ghosts). This will be described in detail below.

[0050] As described above, the converging / diverging unit 32 has the characteristic of converging light in the first polarization state and diverging light in the second polarization state. However, the light emitted from the converging / diverging unit 32 includes light in one of the first and second polarization states (signal light) and light in the other of the first and second polarization states (noise light) as a noise component. That is, when the signal light is converged in the next-stage converging / diverging unit 32, the noise light is diverged, while when the signal light is diverged in the next-stage converging / diverging unit 32, the noise light is converged. As a result, the light that has passed through the multi-stage converging / diverging units 32 is in a state where images reduced and enlarged at different magnifications (powers) overlap. That is, when viewed from the user of the glasses device 10, in addition to the image of the original signal light, images of a plurality of magnifications due to the noise light are seen to overlap, and the usability of the glasses device 10 is reduced.

[0051] The converging / diverging element 34 converts light in the first polarization state into light in the second polarization state and converges it (noise component: light in the first polarization state), and converts light in the second polarization state into light in the first polarization state and diverges it (noise component: light in the second polarization state).

[0052] The control unit 40 controls the plurality of converging / diverging units 32 and the polarization blocking unit 35 as follows in (1) and (2). (1) When the converging / diverging unit 32 at the final stage of the multi-stage converging / diverging unit 32 converges light in the first polarization state, this polarization blocking unit blocks the first polarization. (2) When the converging / diverging unit 32 at the final stage diverges light in the second polarization state, the polarization blocking unit blocks the second polarization.

[0053] FIG. 8 is a table showing an example of diopter switching in the spectacle device 10 according to Embodiment 3 of the present invention. FIG. 9 is a schematic diagram showing an example of the operating state of the lens unit 30 of the spectacle device 10 according to Embodiment 3 of the present invention. FIG. 9 shows the operating state of the lens unit 30 at the uppermost stage of the table in FIG. 8.

[0054] Hereinafter, based on FIGS. 8 and 9, the operating state of the lens unit 30 will be described. Here, it is assumed that a left polarization element (L-pol), an sHWP, and a PB lens are used for the polarization element 31, the conversion element 33, and the converging / diverging element 34, respectively.

[0055] Operating state at A (polarization element 31: POL) The polarization element 31 (L-pol) converts the incident light into left circular polarization (L) and makes it incident on the conversion element 33(1).

[0056] Operating state at B (converging / diverging unit 32(1)) The conversion element 33(1) (sHWP) passes the left circular polarization (L) as it is (transmission state: 0), and the converging / diverging element (1) (PB lens) converts the left circular polarization (L) into right circular polarization (R), diverges it, and makes it incident on the conversion element 33(2).

[0057] Operation state at C (convergence / divergence unit 32(2)) The conversion element 33(2) (sHWP) converts right circular polarization (R) to left circular polarization (L) (inversion state: 1), and the convergence / divergence element (2) converts left circular polarization (L) to right circular polarization (R), diverges it, and makes it incident on the conversion element 33(3).

[0058] Operation state at D (convergence / divergence unit 32(3)) The conversion element 33(3) (sHWP) converts right circular polarization (R) to left circular polarization (L) (inversion state: 1), and the convergence / divergence element (3) converts left circular polarization (L) to right circular polarization (R), diverges it, and makes it incident on the conversion element 33(4).

[0059] Operation state at E (convergence / divergence unit 32(4)) The conversion element 33(4) (sHWP) converts right circular polarization (R) to left circular polarization (L) (inversion state: 1), and the convergence / divergence element (4) converts left circular polarization (L) to right circular polarization (R), diverges it, and makes it incident on the conversion element 33(5).

[0060] Operation state at F (polarization blocking unit 35(5)) The conversion element 33(4) (sHWP) converts right circular polarization (R) to left circular polarization (L) (inversion state: 1), and the polarization element 31(5) allows left circular polarization (L) to pass through and blocks right circular polarization (R). As a result, the noise component (left circular polarization) included in the emitted light from the conversion elements 33(4) (and further, the conversion elements 33(1) to 33(3)) is removed, and the multiple images are eliminated.

[0061] Here, the control unit 40 controls the conversion elements 33(1) to 33(4) so that light is diverged in all of the convergence / divergence units 32(1) to 32(4), and controls the conversion element 33(5) so that the noise components from the conversion elements 33(1) to 33(4) are cut off.

[0062] As described above, according to Embodiment 3, the noise component (left circular polarization) included in the light emitted from the conversion element 33(4) is removed by the polarization blocking unit 35, and the multiple image (ghost) is eliminated.

[0063] [Embodiment 4] Embodiment 4 of the present invention will be described below. For convenience of explanation, members having the same functions as those described in the above embodiments are denoted by the same reference numerals, and their descriptions will not be repeated.

[0064] FIG. 10 is a schematic diagram showing an example of the operating state of the lens unit 30 of the spectacle device 10 according to Embodiment 4 of the present invention. Here, the lens unit 30 (spectacle device 10) includes a polarization blocking unit 35. The lens unit 30 (spectacle device 10) also includes a second converging / diverging element 34(0) disposed between the polarization element 31 and the plurality of converging / diverging units 32. This second converging / diverging element 34(0) functions as an offset lens not controlled by the control unit 40.

[0065] In FIG. 10, the polarization element 31 is a left circular polarization element (L-pol). As a result, when the second converging / diverging element 34(0) is a PB lens, a negative offset is brought about.

[0066] FIG. 11 is a table showing an example of diopter switching in the spectacle device according to Embodiment 5 of the present invention. The control unit 40 controls the conversion elements 33(1) to 33(5) according to this table. As a result, the diopter can be changed within the range of -2D ± 3.75D. Further, the multiple image (ghost) is eliminated by the polarization blocking unit 35(5).

[0067] FIG. 12 is a schematic diagram showing another example of the operating state of the lens unit 30 of the spectacle device 10 according to Embodiment 4 of the present invention. In FIG. 12, since the polarization element 31 is a right circular polarization element (R-pol), a positive offset is brought about. As a result, the diopter can be changed within the range of +2D ± 3.75D. Further, the multiple image (ghost) is eliminated by the polarization blocking unit 35(5).

[0068] As described above, according to Embodiment 4, the second converging / diverging element 34(0) disposed between the polarizing element 31 and the plurality of converging / diverging units 32 can set the diopter offset.

[0069] 〔Embodiment 5〕 Embodiment 5 of the present invention will be described below. For convenience of explanation, members having the same functions as those described in the above embodiments are denoted by the same reference numerals, and the description thereof will not be repeated.

[0070] In Embodiment 5 of the present invention, the lens unit 30 (eyeglass device 10) includes an optical lens disposed in front of, behind, or between the polarizing element 31 and the plurality of converging / diverging units 32. The optical lens is made of an optical material whose refractive index decreases as the wavelength increases in the wavelength range of visible light.

[0071] As described above, the PB lens has a wavelength dependency in which the convergence / divergence of light increases as the wavelength increases, which causes image bleeding due to color. On the other hand, the optical lens has a refractive index that decreases as the wavelength increases, and as a result, acts in a direction to cancel the wavelength dependency of the PB lens. The wavelength dependency of the optical lens is defined by the Abbe number, and the wavelength dependency of the refractive index increases as the Abbe number decreases. For this reason, it is conceivable to use an optical material having a relatively small Abbe number for the optical lens. As an example of this optical material, PC (polycarbonate) having an Abbe number of about 25 to 30 can be mentioned.

[0072] As described above, according to Embodiment 5, by using an optical lens made of an optical material whose refractive index decreases as the wavelength increases in the wavelength range of visible light, the wavelength dependency of the PB lens can be canceled, and the chromatic aberration of the PB lens can be canceled.

[0073] 〔Summary〕 The spectacle device according to aspect 1 of the present invention includes a polarizing element through which external light is incident and which transmits light in a first polarization state or light in a second polarization state orthogonal to the first polarization state, and a converging / diverging unit disposed downstream of the polarizing element and configured to converge or diverge the light incident from the polarizing element. The converging / diverging unit includes a conversion element capable of switching between converting the polarization state of the light from one of the first polarization state and the second polarization state to the other or maintaining the polarization state of the light, and a converging / diverging element disposed downstream of the conversion element and configured to converge the light in the first polarization state and diverge the light in the second polarization state.

[0074] According to the above configuration, it is possible to switch between converging and diverging of light in the lens unit, and switch the spectacle device between myopia use and hyperopia use (or presbyopia use).

[0075] The spectacle device according to aspect 2 of the present invention may, in the above aspect 1, include n (n: an integer of 2 or more) converging / diverging units arranged in multiple stages. According to the above configuration, it is possible to switch the diopter (total diopter) in the lens unit in multiple stages.

[0076] The spectacle device according to aspect 3 of the present invention may, in the above aspect 2, be such that the n converging / diverging units are capable of switching the positive and negative of the spectacle diopter. It is possible to switch the positive and negative of the diopter (total diopter) in the lens unit.

[0077] The spectacle device according to aspect 4 of the present invention may, in the above aspect 2 or 3, be such that the n converging / diverging units have different spectacle diopters from each other. Thereby, it is possible to increase the number of stages of the spectacle diopter (total diopter) in the lens unit that can be switched.

[0078] The spectacle device according to aspect 5 of the present invention may, in any of the above aspects 2 to 4, be such that the n converging / diverging units include one converging / diverging unit having the minimum spectacle diopter, and twice the minimum spectacle diopter mIncluding the other "n - 1" converging / diverging units, each having a diopter corresponding to a multiple (m: integer, 1 ≤ m ≤ n - 1). Thereby, the range of diopters that can be changed can be increased.

[0079] In the spectacle device according to Aspect 6 of the present invention, in any of the above Aspects 2 to 5, the minimum diopter of the n converging / diverging units is 0.25 or less. Thereby, corresponding to the human visual acuity, the diopter can be appropriately switched every 0.5 [D].

[0080] The spectacle device according to Aspect 7 of the present invention, in any of the above Aspects 2 to 6, includes a control unit that controls the plurality of conversion elements to switch the diopter of the spectacle device in 2 n steps. The control unit controls the state of the conversion element, for example, based on a user input and a table representing the relationship between the total diopter and the state of the conversion element.

[0081] The spectacle device according to Aspect 8 of the present invention, in any of the above Aspects 2 to 7, is disposed downstream of the plurality of converging / diverging units and includes a polarization blocking unit that blocks the light in the first polarization state or the light in the second polarization state. The polarization blocking unit includes a second conversion element that can switch between converting the polarization state of the light from one of the first polarization state and the second polarization state to the other or maintaining the polarization state of the light, and a second polarization element that blocks the light in the first polarization state or the light in the second polarization state included in the light emitted from the second conversion element. Thereby, the polarization blocking unit can block noise light and reduce multiple images (ghosts).

[0082] The spectacle device according to aspect 9 of the present invention is, in the above aspect 8, wherein the spectacle device includes a control unit, and the converging / diverging element converts the light in the first polarization state into the light in the second polarization state and converges it, and converts the light in the second polarization state into the light in the first polarization state and diverges it. When the converging / diverging unit in the final stage of the multi-stage converging / diverging unit converges the light in the first polarization state, the control unit controls the plurality of converging / diverging units and the polarization blocking unit such that the polarization blocking unit blocks the first polarization. When the converging / diverging unit in the final stage diverges the light in the second polarization state, the polarization blocking unit blocks the second polarization. Thereby, by the control unit controlling the plurality of converging / diverging units and the polarization blocking unit, it becomes possible to more reliably reduce multiple images (ghosts).

[0083] The spectacle device according to aspect 10 of the present invention includes, in any one of the above aspects 2 to 9, a second converging / diverging element disposed between the polarization element and the plurality of converging / diverging units. Thereby, the second converging / diverging element can function as an offset lens.

[0084] The spectacle device according to aspect 11 of the present invention includes, in any one of the above aspects 2 to 10, an optical lens disposed in front of, behind, or between the polarization element and the plurality of converging / diverging units. By the optical lens, it becomes possible to cancel the wavelength characteristics of the converging / diverging unit.

[0085] The spectacle device according to aspect 12 of the present invention is, in the above aspect 10, wherein the optical lens is composed of an optical material in which the refractive index decreases as the wavelength increases in the wavelength range of visible light. Thereby, it becomes possible to more reliably cancel the wavelength characteristics of the converging / diverging unit.

[0086] The eyeglass device according to aspect 13 of the present invention is, in any of the above aspects 1 to 12, wherein the plurality of converging / diverging units have a pair of portions respectively corresponding to a pair of human eyes, the pair of portions each have an optical axis, and the distance between the optical axes of the pair of portions is smaller than the distance between the geometric centers of the pair of portions. Thereby, the user can widely view left and right through the eyeglass device.

[0087] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. Furthermore, by combining the technical means disclosed in each embodiment, new technical features can be formed.

Explanation of Reference Numerals

[0088] 10 Eyeglass device 20 Frame 21 Holding portion 30, 30a, 30b Lens portion 31 Polarizing element 32 Converging / diverging unit 33 Conversion element 34 Converging / diverging element 35 Polarization blocking unit 40 Control unit

Claims

1. A polarizing element that allows external light to enter and transmits light in a first polarization state or light in a second polarization state orthogonal to the first polarization state; A converging / diverging unit disposed downstream of the polarizing element that converges or diverges the light incident from the polarizing element, comprising: The converging / diverging unit includes: A conversion element capable of switching to convert the polarization state of light from one of the first polarization state and the second polarization state to the other or to maintain the polarization state of the light; A converging / diverging element disposed downstream of the conversion element that converges the light in the first polarization state and diverges the light in the second polarization state; An eyewear device.

2. Comprising n (n: an integer of 2 or more) of the converging / diverging units arranged in multiple stages, The eyewear device according to Claim 1.

3. The eyewear device according to Claim 2, wherein the n converging / diverging units are capable of switching the positive / negative of the eyeglass power.

4. The eyewear device according to Claim 2 or 3, wherein the n converging / diverging units have different eyeglass powers from each other.

5. The n converging / diverging units include: One converging / diverging unit having the minimum eyeglass power; two times the minimum eyeglass power ｍ The eyeglass device according to claim 2, further comprising another "n-1" converging / diverging units each having an eyeglass power corresponding to m times (m is an integer, 1 ≤ m ≤ n-1) the minimum eyeglass power.

6. The eyewear device according to Claim 2, wherein the minimum eyeglass power of the n converging / diverging units is 0.25 or less.

7. Controlling the plurality of conversion elements, The spectacle power of the spectacle device can be switched in two steps ｎ The spectacle device according to claim 2, further comprising a control unit capable of switching in two steps

8. Comprising a polarization blocking unit disposed downstream of the plurality of converging / diverging units that blocks the light in the first polarization state or the light in the second polarization state, The polarization blocking unit includes: A second conversion element capable of switching to convert the polarization state of light from one of the first polarization state and the second polarization state to the other or to maintain the polarization state of the light; A second polarizing element that blocks the light in the first polarization state or the light in the second polarization state included in the light emitted from the second conversion element; The eyewear device according to Claim 2.

9. The eyewear device includes a control unit, The converging / diverging element: Converts the light in the first polarization state into the light in the second polarization state and converges it; Converts the light in the second polarization state into the light in the first polarization state and diverges it; The control unit: When the converging / diverging unit at the final stage of the multi-stage converging / diverging unit converges the light in the first polarization state, the polarization blocking unit blocks the first polarization. When the final-stage convergence / divergence unit diverges the light in the second polarization state, the polarization blocking unit blocks the second polarization. The spectacle device according to claim 8, which controls the plurality of convergence / divergence units and the polarization blocking unit.

10. The spectacle device according to claim 2, further comprising a second convergence / divergence element disposed between the polarization element and the plurality of convergence / divergence units.

11. The spectacle device according to claim 2, further comprising an optical lens disposed in front of, behind, or between the polarization element and the plurality of convergence / divergence units.

12. The spectacle device according to claim 11, wherein the optical lens is made of an optical material whose refractive index decreases as the wavelength increases in the wavelength range of visible light.

13. The plurality of convergence / divergence units have a pair of parts respectively corresponding to a pair of human eyes. Each of the pair of parts has an optical axis. The distance between the optical axes of the pair of parts is smaller than the distance between the geometric centers of the pair of parts. The spectacle device according to claim 1.

Images