Eyeglass device

Abstract

An eyeglass device (10) comprises: a polarizing element (31) into which external light enters and which transmits one of light in a right circular polarization state and light in a left circular polarization state and blocks the other; and a converging / diverging unit (32) which is disposed downstream of a first polarizing element and which is capable of switching between convergence and divergence of incoming light from the polarizing element, wherein the converging / diverging unit has a transforming element (33) which is capable of switching between transformation of the polarization state of light from one of the right circular polarization state and the left circular polarization state to the other and maintenance of the polarization state of light and a converging / diverging element (34) which is disposed downstream of the transforming element and which converges one of light in the right circular polarization state and light in the left circular polarization state and causes the other to diverge.

Description

eyeglass equipment

[0001] The present invention relates to an eyewear device.

[0002] A technology for multifocal glasses is known that has a first lens and a second lens whose focal length changes when a voltage is applied, and in which multiple voltage values ​​are repeatedly applied to the second lens in steps at a predetermined cycle (see Patent Document 1).

[0003] Also known is a technology for variable refraction control glasses having a polarizing film 4, a liquid crystal layer 6, and lenses 7 and 8 (see Patent Document 2). Linearly polarized light selected from incident light 3 by the polarizing film 4 is incident on the liquid crystal layer 6 and then on the lenses 7 and 8. The liquid crystal layer 6 switches the polarization direction of the linearly polarized light between two orthogonal directions depending on whether or not a voltage is applied. The lenses 7 and 8 function as a convex lens and a concave lens depending on the polarization direction. As a result, vision correction is possible.

[0004] Japanese Patent Publication No. 2007-212623 Japanese Patent Publication No. 2002-323680

[0005] The technology of Patent Document 1 is intended to realize multifocal eyeglasses, but is not intended to change the eyeglasses' power according to changes in the user's eyesight. The technology of Patent Document 2 utilizes switching of linearly polarized light between two orthogonal directions, but does not utilize circularly polarized light.

[0006] An object of one aspect of the present invention is to provide an eyeglass device that can change the prescription of eyeglasses by using circularly polarized light.

[0007] In order to solve the above problem, an eyewear device according to one aspect of the present invention includes a polarizing element that receives external light and transmits either right-handed circularly polarized light or left-handed circularly polarized light while blocking the other, and a converging / diverging unit that is arranged downstream of the first polarizing element and is capable of switching between converging and diverging the light incident from the polarizing element, wherein the converging / diverging unit has a conversion element that is capable of switching between converting the polarization state of the light from one of the right-handed circularly polarized state and the left-handed circularly polarized state to the other, or maintaining the polarization state of the light, and a converging / diverging element that is arranged downstream of the conversion element and converges either the right-handed circularly polarized light or the left-handed circularly polarized light and diverges the other.

[0008] According to one aspect of the present invention, an eyewear device capable of switching the eyeglass power by using circularly polarized light can be realized.

[0009] FIG. 2 is a perspective view showing an eyeglass device according to a first embodiment of the present invention. FIG. 3 is a perspective view showing an example of a state in which the eyeglass device is worn by a user. FIG. 4 is an enlarged view of a portion of FIG. 2. FIG. 5 is a schematic view showing an example of the configuration of a lens unit. FIG. 6 is a schematic view showing a lens unit of an eyeglass device according to a second embodiment of the present invention. FIG. 7 is a table showing an example of switching of eyeglass power in an eyeglass device according to the second embodiment of the present invention. FIG. 8 is a schematic view showing a lens unit of an eyeglass device according to a third embodiment of the present invention. FIG. 9 is a table showing an example of switching of eyeglass power in an eyeglass device according to the third embodiment of the present invention. FIG. 10 is a schematic view showing an example of an operating state of the lens unit of an eyeglass device according to the third embodiment of the present invention. FIG. 11 is a schematic view showing an example of an operating state of the lens unit of an eyeglass device according to a fourth embodiment of the present invention. FIG. 12 is a table showing an example of switching of eyeglass power in an eyeglass device according to the fourth embodiment of the present invention. FIG. 13 is a schematic view showing an example of an operating state of the lens unit of an eyeglass device according to the fourth embodiment of the present invention.

[0010] [Embodiment 1] An embodiment of the present invention will be described in detail below. Fig. 1 is a perspective view showing an eyewear device 10 according to embodiment 1 of the present invention. The eyewear device 10 has a frame 20, a lens unit 30, and a control unit 40.

[0011] The frame 20 has a holding portion 21 that holds the lens portion 30, ear pieces 22 that are placed on the ears of a user (human), and nose pieces 23 that are placed on the nose of the user.

[0012] 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 allow it to enter the user's eyes. The powers of the lens units 30a and 30b (also called "eyeglass powers") are switchable. The lens units 30a and 30b will be described in detail later.

[0013] This switching can be performed by the user as appropriate. For example, the eyewear device 10 may include a switch unit for switching the power. The switch unit can be installed, for example, to the side of the frame 20 (for example, at the earpiece 22 or in the area from the holder 21 to the earpiece 22). Placing the switch unit to the side of the frame 20 improves user operability. In other words, the user can switch the power by operating the switch unit while wearing the eyeglasses and looking at an object. The switch unit functions as a receiving unit that receives user input and receives input to switch the eyeglass power of the convergence / divergence unit 32 (described later) between positive and negative.

[0014] The switching may also be performed from an external device such as a mobile terminal (e.g., a smartphone). For example, the eyewear device 10 may include a communication unit (e.g., Bluetooth (registered trademark) or Wi-Fi (registered trademark)) that can communicate with an external device such as a mobile terminal, and the user may switch the power by operating the mobile terminal. The communication unit receives a signal from the external device and functions as a reception unit that receives an input for switching the eyeglass power of the convergence / divergence unit 32 (described later) between positive and negative.

[0015] Furthermore, the switch unit and the portable terminal may be used together. For example, the portable terminal may be used to set multiple powers as presets from the variable power range of the eyewear device 10, and the switch unit may be used to sequentially switch between the multiple set powers. For example, from the powers shown in FIG. 6 (described later), −3.75 and 1.75 may be selected (set) as presets, and the switch unit may be used to alternate between −3.75 and 1.75. In this case, the bifocal power selected on the portable terminal is switched using the switch unit of the eyewear device 10. Note that both the setting of the preset powers and the power switching may be performed on the portable terminal.

[0016] The control unit 40 controls the operation of the eyewear device 10, particularly the lens units 30a and 30b. The control unit 40 will be described in detail later.

[0017] Fig. 2 is a perspective view showing an example of a state in which a user wears the eyewear device, and Fig. 3 is an enlarged view of a part of Fig. 2.

[0018] 3, the lens portions 30a and 30b have a substantially rectangular 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 portions 30a and 30b may have a circular or elliptical shape. The lens portions 30a and 30b have optical axes Aoa and Aob and geometric centers Cga and Cgb, respectively.

[0019] The optical axes Aoa and Aob refer to the central axes of convergence and divergence of light at the lens portions 30a and 30b, respectively, and pass through the focal points when light converges. The intersections of the optical axes Aoa and Aob with the lens portions 30a and 30b are the optical centers Coa and Cob. The optical centers Coa and Cob are preferably located, for example, at approximately 2 / 5 of the outer dimensions of the lens portions 30a and 30b. Here, the optical center Cob is located at a distance Dx from the inner edge of the lens portion 30b and a distance Dy from the upper edge of the lens portion 30b. For example, the distance Dx is 20 mm and the distance Dy is 12 mm.

[0020] The geometric centers Cga and Cgb refer to the centers of the lens portions 30a and 30b when viewed from the outside, and are the centers of the surface shapes of the lens portions 30a and 30b when viewed from the outside.

[0021] The optical axes Aoa and Aob are generally set to correspond to the centers of the eyes (pupils) of a 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 outward to the left and right of the centers of the user's eyes (pupils). This is to allow the user to see a wide range to the left and right through the lens units 30a and 30b. As a result, as shown in FIG. 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 is greater than or equal to the distance D, the range that the user can see to the left and right through the lens units 30a and 30b becomes narrower.

[0022] The optical axes Aoa and Aob (optical centers Coa and Cob) are determined by the lens units 30a and 30b, and in particular by the converging / diverging units 32 (which constitute the lens units 30a and 30b) described below. Therefore, the (plural) converging / diverging units 32 may have a pair of portions (corresponding to the lens units 30a and 30b) corresponding to a pair of human eyes, respectively, and each of these pair of portions may have an optical axis.

[0023] 4 is a schematic diagram showing an example of the configuration of the lens unit 30 (30a, 30b). The lens unit 30 receives light L1 from the outside world, converges or diverges the light L1, and causes the light L1 to enter the user's eye E as light L2. The user can clearly view an image of the outside world through the eyeglass device 10 (lens unit 30) by converging or diverging the light in accordance with the user's eyesight. The lens unit 30 (eyeglass device 10) has a polarizing element 31 and a converging / diverging unit 32.

[0024] The polarizing element 31 is an element that receives incident external light and transmits light of a first polarization state or light of a second polarization state orthogonal to the first polarization state. The first and second polarization states are, for example, right-handed circular polarization and left-handed circular polarization. The polarizing element 31 can be, for example, a circular polarizer (hereinafter also referred to as "pol"), i.e., a right-handed circular polarizer (hereinafter also referred to as "R-pol") that transmits right-handed circularly polarized light, or a left-handed circular polarizer (hereinafter also referred to as "L-pol") that transmits left-handed circularly polarized light. The circular polarizing element can be composed of, for example, a linear polarizer and a quarter-wave plate. By setting the angle between the axes of the linear polarizer and the quarter-wave plate, it can be made into a right-handed circular polarizing element or a left-handed circular polarizing element.

[0025] The converging / diverging unit 32 is disposed after the polarizing element 31, and is an element that converges or diverges the light incident from the polarizing element 31. The converging / diverging unit 32 includes a conversion element 33 and a converging / diverging element .

[0026] The conversion element 33 is an element that can switch 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 be a switchable half-wave plate (hereinafter also referred to as "sHWP") that can switch the phase difference between a half wavelength and zero wavelength by applying a voltage. The conversion element 33 has two states: a transmission state (phase difference: zero) that passes right-handed and left-handed circularly polarized light as is, and an inversion state (phase difference: half wavelength) that converts right-handed circularly polarized light to left-handed circularly polarized light and left-handed circularly polarized light to right-handed circularly polarized light. Therefore, the eyeglass device 10 includes a voltage supply unit (not shown) that supplies voltage to the conversion element 33. The voltage supply unit is controlled by the control unit 40 to switch the state of the conversion element 33 (transmission state, inversion state).

[0027] The voltage supply unit may have a rechargeable battery, which eliminates the need to connect the eyewear device 10 to a power source via a power cable. As a result, the eyewear device 10 will not come off the user's body due to the user's fingers or other factors getting caught on the power cable.

[0028] The battery may be located, for example, at any position on the side of the frame 20 near the lens unit 30. In this case, batteries of approximately the same weight may be installed on both the left and right sides of the frame 20. This ensures left-right balance of the eyeglass device 10, improving the comfort of the user wearing the eyeglass device 10. It also prevents the eyeglass device 10 from coming off the user and falling due to an imbalance in the weight of the left and right sides of the eyeglass device 10.

[0029] The eyewear device 10 may include a power cable connection terminal. When the battery is low, the battery can be charged by connecting the power source to the eyewear device 10 with the power cable. Note that, as described below, if wireless charging of the battery is possible, the power cable connection terminal may be omitted.

[0030] The eyewear device 10 may include a wireless charging unit that enables wireless charging of the battery. When batteries are arranged on the left and right sides of the frame 20, the frame 20 may be folded and overlapped to wirelessly charge both batteries at the same time.

[0031] The converging / diverging element 34 is disposed after the conversion element 33 and converges light of a first polarization state and diverges light of a second polarization state. A Pancharatnam-Berry lens (hereinafter also referred to as a "PB lens") can be used as the converging / diverging element 34. The PB lens can be made using a liquid crystal polymer. For example, (1) an alignment film pattern (alignment pattern) for aligning liquid crystal polymer molecules is formed on a light-transmitting substrate, and (2) a liquid crystal polymer is applied to the alignment film pattern and cured by ultraviolet (UV) or the like. In the PB lens, the liquid crystal molecules are arranged with periodicity in multiple circumferential directions with a common center. As a result, the PB lens functions as a polarized diffractive lens and can converge or diverge light.

[0032] In this embodiment, the PB lens converges right-handed circularly polarized light and diverges left-handed circularly polarized light. More specifically, the PB lens outputs incident right-handed circularly polarized light as converging left-handed circularly polarized light, and outputs incident left-handed circularly polarized light as diverging right-handed circularly polarized light. Such a PB lens can be formed, for example, by one or both of an orientation pattern of liquid crystal in the PB lens and / or multi-layering of the PB lens.

[0033] The following description will be given taking a PB lens that "converges incident right-handed circularly polarized light and diverges incident left-handed circularly polarized light" as an example of the converging / diverging element 34. However, it is also possible to use a PB lens that "converges incident left-handed circularly polarized light and diverges incident right-handed circularly polarized light" as the converging / diverging element 34.

[0034] Here, when converging left-handed circularly polarized light is emitted from the PB lens, the emitted light may contain right-handed circularly polarized light as a noise component. On the other hand, when diverging right-handed circularly polarized light is emitted from the PB lens, the emitted light may contain left-handed circularly polarized light as a noise component. This noise component causes overlapping images (ghost images) for the user. A method for eliminating this problem will be described in embodiment 3.

[0035] PB lenses can have wavelength dependency. That is, because PB lenses utilize the diffraction phenomenon of light, the focal length tends to become shorter (the diffraction angle becomes larger) as the wavelength of light becomes longer, and the focal length tends to become longer (the diffraction angle becomes smaller) as the wavelength of light becomes shorter. That is, with PB lenses, the convergence / divergence of light increases as the wavelength of light becomes longer. This wavelength dependency causes chromatic aberration, i.e., the blurring of images due to color that users perceive as blurring. A method for eliminating this problem will be described in embodiment 4.

[0036] The control unit 40 switches the power of the lens units 30a, 30b. The control unit 40 switches the power of the lens units 30a, 30b, for example, based on information input from the user. Specifically, the control unit 40 controls a voltage application unit that applies voltage to the conversion element 33, thereby switching the state of the conversion element 33 and, ultimately, the power of the lens units 30a, 30b. The control unit 40 can control the state of the conversion element based on, for example, user input and a table (see, for example, FIGS. 6, 8, and 11) that shows the relationship between the total power and the state of the conversion element.

[0037] Here, the operation of the eyeglass device 10 will be described assuming that the polarizing element 31, the converting element 33, and the converging / diverging element 34 are a left-handed circularly polarizing element (L-pol), an sHWP, and a PB lens, respectively. The sHWP is switched by the control unit 40 between a transmission state (phase difference: zero) that passes left-handed circularly polarized light (and right-handed circularly polarized light) as is, and an inversion state (phase difference: 1 / 2 wavelength) that converts left-handed circularly polarized light into right-handed polarized light and right-handed circularly polarized light into left-handed polarized light.

[0038] When the sHWP is in the transmission state, the left-handed circularly polarized light emitted from the L-pol is incident on the PB lens as is and is diverged by the PB lens. On the other hand, when the sHWP is in the inversion state, the left-handed circularly polarized light emitted from the L-pol is converted to right-handed circularly polarized light and incident on the PB lens, where it is converged by the PB lens.

[0039] As described above, according to the first embodiment, the control unit 40 can switch the state of the conversion element 33 to switch between convergence and divergence of light at the lens unit 30, thereby switching the eyeglass device 10 between myopia and hyperopia (or presbyopia).

[0040] [Embodiment 2] A second embodiment of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0041] 5 is a schematic diagram illustrating the lens unit 30 of the eyewear device 10 according to a second embodiment of the present invention. In the second embodiment, the lens unit 30 includes n (n: an integer of 2 or more) converging / diverging units 32 arranged in multiple stages. Here, as an example, the number n of converging / diverging units 32 is set to 4.

[0042] The n converging / diverging units 32 can be switched between positive and negative eyeglass powers by the control unit 40. It is preferable that the n converging / diverging units 32 have different eyeglass powers from each other. For example, the n converging / diverging units may include one converging / diverging unit 32 having the minimum eyeglass power and two converging / diverging units 32 having the minimum eyeglass power. ｍ and other "n-1" convergence / divergence units each having eyeglass powers corresponding to m times m (m: integer, 1≦m≦n-1). Here, the minimum eyeglass power of the n convergence / divergence units may be, for example, 0.25 [D] or less. By setting the minimum eyeglass power to 0.25 [D], it becomes possible to switch the power in increments of 0.5 [D] to suit the human eye.

[0043] 6 is a table showing an example of power switching in the eyeglass device according to the second embodiment of the present invention. The control unit 40 can switch between positive and negative eyeglass powers in the convergence / divergence units 32(1) to 32(4) of stages (1) to (4). In the convergence / divergence unit 32(4) of stage (4), the (minimum) eyeglass power of 0.25 [D] is switched between positive and negative. On the other hand, the conversion elements 33(3) to 33(1) are respectively switched between positive and negative for the minimum eyeglass power of 0.25 [D]. １ double, two ２ double, two ３ The eyeglasses powers of 0.5 [D], 1.0 [D], and 2.0 [D] can be switched between positive and negative. For ease of understanding, the powers are shown in order of decreasing from step (1) to step (4), but this order may be changed as appropriate.

[0044] The control unit 40 changes the eyeglass prescription of the eyeglass device 10 (lens unit 30) between two or more states (transmission state, inversion state) of the plurality of conversion elements 33 based on the table shown in FIG. 6, for example. ｎHere, the power (total power) of the eyeglass device 10 (lens unit 30) can be changed in 0.5 D increments within the range of -3.75 D to +3.75 D. As a result, it is easy to accommodate a wide range of vision, from myopia to hyperopia (presbyopia).

[0045] As described above, according to the second embodiment, the control unit 40 can switch the state (transmitting state, inverting state) of the multiple conversion elements 33, thereby switching the power (total power) of the lens unit 30 in multiple stages.

[0046] [Embodiment 3] A third embodiment of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0047] 7 is a schematic diagram showing the lens unit 30 of the eyeglass device 10 according to the third embodiment of the present invention. Here, the eyeglass device 10 includes a polarization blocking unit 35(5) in the final stage (stage (5)). The polarization blocking unit 35(5) is disposed after the plurality of converging / diverging units 32 and blocks light of the first polarization state or the second polarization state.

[0048] The polarization blocking unit 35 has a second conversion element 33(5) and a second polarizing element 31(5). The second conversion element 33(5) is an element that can switch 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 similar to the conversion element 33 in the previous stage.

[0049] The second polarizing element 31(5) is an element that blocks light of the first polarization state or light of the second polarization state contained in the light emitted from the second conversion element 33(5), and may be similar to the polarizing element 31 in the previous stage.

[0050] In this embodiment, the provision of the polarization blocking unit 35(5) makes it possible to eliminate double images (ghost images), as will be explained in detail below.

[0051] As described above, the converging / diverging unit 32 has the characteristic of converging light of a first polarization state and diverging light of a second polarization state. However, the light output from the converging / diverging unit 32 contains light of one of the first and second polarization states (signal light) and light of 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 converging / diverging unit 32 of the next stage, the noise light is diverged, and conversely, when the signal light is diverged in the converging / diverging unit 32 of the next stage, the noise light is converged. As a result, the light passing through the multiple converging / diverging units 32 becomes a state in which images reduced and enlarged at different magnifications (powers) are superimposed on each other. That is, from the perspective of the user of the eyeglass device 10, in addition to the image of the original signal light, images of multiple magnifications due to the noise light are superimposed, which reduces the usability of the eyeglass device 10.

[0052] The converging / diverging element 34 converts light of a first polarization state into light of a second polarization state and converges it (noise component: light of the first polarization state), and converts light of the second polarization state into light of the first polarization state and diverges it (noise component: light of the second polarization state).

[0053] The control unit 40 controls the multiple converging / diverging units 32 and the polarization blocking unit 35 as follows: (1) When the final converging / diverging unit 32 of the multi-stage converging / diverging units 32 converges light of a first polarization state, the polarization blocking unit blocks the first polarization. (2) When the final converging / diverging unit 32 diverges light of a second polarization state, the polarization blocking unit blocks the second polarization.

[0054] Fig. 8 is a table showing an example of switching of power in the eyeglass device 10 according to the third embodiment of the present invention. Fig. 9 is a schematic diagram showing an example of an operating state of the lens unit 30 of the eyeglass device 10 according to the third embodiment of the present invention. Fig. 9 shows the operating state of the lens unit 30 at the top of the table in Fig. 8.

[0055] 8 and 9, the operating state of the lens unit 30 will be described. Here, it is assumed that a left-handed polarizing element (L-pol), an sHWP, and a PB lens are used for the polarizing element 31, the converting element 33, and the converging / diverging element 34, respectively.

[0056] A (Operating state of polarizing element 31: POL) The polarizing element 31 (L-pol) converts the incident light into left-handed circularly polarized light (L) and makes it incident on the conversion element 33 (1).

[0057] Operating state in B (convergence / divergence unit 32(1)) The conversion element 33(1) (sHWP) passes the left-handed circularly polarized light (L) as is (transmission state: 0), and the converging / divergence element (1) (PB lens) converts the left-handed circularly polarized light (L) into right-handed circularly polarized light (R), diverges it, and makes it incident on the conversion element 33(2).

[0058] C (Operating state in converging / diverging unit 32(2)) The conversion element 33(2) (sHWP) converts right-handed circularly polarized light (R) into left-handed circularly polarized light (L) (inverted state: 1), and the converging / diverging element (2) converts left-handed circularly polarized light (L) into right-handed circularly polarized light (R), diverges it, and makes it incident on the conversion element 33(3).

[0059] D (Operating state in converging / diverging unit 32(3)) The conversion element 33(3) (sHWP) converts right-handed circularly polarized light (R) into left-handed circularly polarized light (L) (inverted state: 1), and the converging / diverging element (3) converts left-handed circularly polarized light (L) into right-handed circularly polarized light (R), diverges it, and makes it incident on the conversion element 33(4).

[0060] E (Operating state in converging / diverging unit 32(4)) The conversion element 33(4) (sHWP) converts right-handed circularly polarized light (R) into left-handed circularly polarized light (L) (inverted state: 1), and the converging / diverging element (4) converts left-handed circularly polarized light (L) into right-handed circularly polarized light (R), diverges it, and makes it incident on the conversion element 33(5).

[0061] F (polarization blocking unit 35(5)) operating state The conversion element 33(4) (sHWP) converts right-handed circularly polarized light (R) to left-handed circularly polarized light (L) (inversion state: 1), and the polarizing element 31(5) passes left-handed circularly polarized light (L) and blocks right-handed circularly polarized light (R). As a result, noise components (left-handed circularly polarized light) contained in the light emitted from the conversion element 33(4) (and conversion elements 33(1) to 33(3)) are removed, and overlapping images are eliminated.

[0062] Here, the control unit 40 controls the conversion elements 33(1) to 33(4) so ​​that light is diverged in all of the converging / diverging units 32(1) to 32(4), and controls the conversion element 33(5) so that noise components from the conversion elements 33(1) to 33(4) are cut.

[0063] As described above, according to the third embodiment, the polarization blocking unit 35 removes noise components (left-handed circularly polarized light) contained in the light emitted from the conversion element 33(4), thereby eliminating overlapping images (ghosts).

[0064] [Embodiment 4] A fourth embodiment of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiments, and the description thereof will not be repeated.

[0065] 10 is a schematic diagram illustrating an example of an operating state of the lens unit 30 of the eyeglass device 10 according to the fourth embodiment of the present invention. Here, the lens unit 30 (eyeglass device 10) includes a polarization blocking unit 35. The lens unit 30 (eyeglass device 10) also includes a second converging / diverging element 34(0) disposed between the polarizing element 31 and the plurality of converging / diverging units 32. This second converging / diverging element 34(0) functions as an offset lens that is not controlled by the control unit 40.

[0066] 10, the polarizing element 31 is a left-handed circular polarizing element (L-pol), which results in a negative offset when the second converging / diverging element 34(0) is a PB lens.

[0067] 11 is a table showing an example of power switching in an eyeglass device according to the fifth embodiment 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 power can be changed within a range of -2D±3.75D. In addition, the polarization blocking unit 35(5) eliminates overlapping images (ghosts).

[0068] FIG. 12 is a schematic diagram showing another example of the operating state of the lens unit 30 of the eyeglass device 10 according to the fourth embodiment of the present invention. In FIG. 12, the polarizing element 31 is a right-handed circular polarizing element (R-pol), which results in a positive offset. As a result, the power can be changed within a range of +2D±3.75D. In addition, the polarization blocking unit 35(5) eliminates overlapping images (ghost images).

[0069] As described above, according to the fourth embodiment, the second converging / diverging element 34 ( 0 ) disposed between the polarizing element 31 and the plurality of converging / diverging units 32 can set an offset in power.

[0070] [Embodiment 5] A fifth embodiment of the present invention will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiments, and the description thereof will not be repeated.

[0071] In the fifth embodiment of the present invention, the lens unit 30 (eyeglasses device 10) includes a polarizing element 31 and an optical lens disposed before, after, or between the plurality of converging / diverging units 32. The optical lens is made of an optical material whose refractive index decreases as the wavelength becomes longer in the wavelength range of visible light.

[0072] As mentioned above, PB lenses have wavelength dependency, in which the convergence / divergence of light increases as the wavelength increases, causing color image blur. In contrast, the refractive index of optical lenses decreases as the wavelength increases, which acts to cancel out the wavelength dependency of PB lenses. The wavelength dependency of optical lenses is determined by their Abbe number, and as the Abbe number decreases, the wavelength dependency of the refractive index increases. For this reason, it is considered to use optical materials with a relatively small Abbe number for optical lenses. One example of such an optical material is PC (polycarbonate), which has an Abbe number of approximately 25 to 30.

[0073] As described above, according to the fifth embodiment, by using an optical lens made of an optical material whose refractive index decreases as the wavelength becomes longer in the wavelength range of visible light, it is possible to cancel the wavelength dependency of the PB lens and thereby eliminate the chromatic aberration of the PB lens.

[0074] [Summary] An eyewear device according to aspect 1 of the present invention comprises a polarizing element that receives incident external light and transmits either right-handed circularly polarized light or left-handed circularly polarized light while blocking the other, and a converging / diverging unit that is arranged downstream of the polarizing element and is capable of switching between converging and diverging the light incident from the polarizing element, wherein the converging / diverging unit has a conversion element that is capable of switching between converting the polarization state of the light from one of the right-handed circularly polarized state and the left-handed circularly polarized state to the other, or maintaining the polarization state of the light, and a converging / diverging element that is arranged downstream of the conversion element and converges either the right-handed circularly polarized light or the left-handed circularly polarized light and diverges the other.

[0075] According to the above configuration, the convergence and divergence of light at the lens section can be switched, and the eyeglass device can be switched between myopia and hyperopia (or presbyopia).

[0076] The eyeglass device according to Aspect 2 of the present invention may be configured as in Aspect 1, further comprising n (n: an integer of 2 or more) converging / diverging units arranged in multiple stages. With the above configuration, the power (total power) of the lens section can be switched in multiple stages.

[0077] In the eyewear device according to Aspect 3 of the present invention, in the above-mentioned Aspect 2, the n converging / diverging units may be capable of switching between positive and negative eyeglass powers. The power (total power) of the lens portion can be switched between positive and negative.

[0078] In the eyeglass device according to Aspect 4 of the present invention, in the above-mentioned Aspects 2 or 3, the n converging / diverging units may have different eyeglass powers from each other, thereby increasing the number of levels of eyeglass power (total power) that can be switched in the lens units.

[0079] In the eyeglass device according to Aspect 5 of the present invention, in any one of Aspects 2 to 4, the n converging / diverging units include one converging / diverging unit having a minimum eyeglass power and two converging / diverging units having the minimum eyeglass power. ｍ and other "n-1" convergence / divergence units each having eyeglass powers corresponding to m times (m: integer, 1≦m≦n-1) times the optical power of the eyeglasses. This allows the range of eyeglass powers that can be changed to be wider.

[0080] In the eyeglass device according to Aspect 6 of the present invention, in any one of Aspects 2 to 5, the minimum eyeglass power of the n converging / diverging units is 0.25 or less, thereby enabling the eyeglass power to be appropriately switched in increments of 0.5 [D] in accordance with human visual acuity.

[0081] According to a seventh aspect of the present invention, in any one of the second to sixth aspects, the eyewear device further includes a receiving unit that receives an input for switching between convergence and divergence of light of the n converging / diverging units, and switches between convergence and divergence of light of the n converging / diverging units based on the switching input, thereby enabling switching of eyeglass prescription based on the switching input.

[0082] In an eyewear device according to Aspect 8 of the present invention, in the above-mentioned Aspect 7, the reception unit is a switch unit that receives a user input or a communication unit that receives a signal from an external device, thereby making it possible to switch the eyeglasses power based on the user input or the signal from the external device.

[0083] According to a ninth aspect of the present invention, in any one of the second to eighth aspects, the eyeglass device controls the plurality of conversion elements to change the eyeglass prescription of the eyeglass device to two or more. ｎ The control unit controls the state of the conversion elements based on, for example, a user's input and a table that indicates the relationship between the total frequency and the state of the conversion elements.

[0084] According to a tenth aspect of the present invention, in any one of the second to ninth aspects, the eyewear device further includes a polarization blocking unit disposed downstream of the plurality of converging / diverging units, which blocks the right-handed circularly polarized light or the left-handed circularly polarized light, and the polarization blocking unit includes a second conversion element that can switch between converting the polarization state of the light from one of the right-handed circularly polarized state and the left-handed circularly polarized state to the other, or maintaining the polarization state of the light, and a second polarizing element that blocks the right-handed circularly polarized light or the left-handed circularly polarized light contained in the light output from the second conversion element. This allows the polarization blocking unit to block noise light and reduce overlapping images (ghosts).

[0085] According to an eleventh aspect of the present invention, in the eyeglass device of the tenth aspect, the eyeglass device further includes a control unit, wherein the converging / diverging element converts light of one of the right-handed and left-handed circularly polarized states into light of the other polarized state and converges the light, and converts the light of the other polarized state into light of the one polarized state and diverges the light, and the control unit controls the plurality of converging / diverging units and the polarization blocking units so that when a final-stage converging / diverging unit of the multi-stage converging / diverging units converges the light of the one polarized state, the polarization blocking unit blocks the light of the one polarized state, and when the final-stage converging / diverging unit diverges the light of the other polarized state, the polarization blocking unit blocks the light of the other polarized state. This makes it possible for the control unit to more reliably reduce overlapping images (ghosts) by controlling the plurality of converging / diverging units and the polarization blocking units.

[0086] According to a twelfth aspect of the present invention, in any one of the second to eleventh aspects, the eyewear device further includes a second converging / diverging element disposed between the polarizing element and the plurality of converging / diverging units, whereby the second converging / diverging element can function as an offset lens.

[0087] The eyeglass device according to Aspect 13 of the present invention is the eyeglass device according to any one of Aspects 2 to 12, further comprising an optical lens disposed before, after, or between the polarizing element and the plurality of converging / diverging units, which can cancel the wavelength characteristics of the converging / diverging units.

[0088] According to Aspect 14 of the present invention, in the eyeglass device of Aspect 13, the optical lens is made of an optical material whose refractive index decreases as the wavelength increases in the visible light wavelength range, thereby making it possible to more reliably cancel the wavelength characteristics of the converging / diverging unit.

[0089] According to Aspect 15 of the present invention, in any one of Aspects 1 to 14, the plurality of converging / diverging units have a pair of portions corresponding to a pair of human eyes, each of the pair of portions having 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 enabling the user to see widely to the left and right through the eyeglass device.

[0090] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of 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, new technical features can be formed by combining the technical means disclosed in each embodiment.

[0091] REFERENCE SIGNS LIST 10 Eyeglass device 20 Frame 21 Holding portion 30, 30a, 30b Lens portion 31 Polarizing element 32 Converging / diverging unit 33 Converting element 34 Converging / diverging element 35 Polarization blocking unit 40 Control portion

Claims

1. An eyeglass device comprising: a polarizing element that receives incident external light, transmits either right-handed circularly polarized light or left-handed circularly polarized light, and blocks the other; and a convergence / divergence unit that is arranged downstream of the polarizing element and is capable of switching between converging and diverging the light incident from the polarizing element, wherein the convergence / divergence unit has: a conversion element that is capable of switching between converting the polarization state of the light from one of the right-handed circularly polarized state and the left-handed circularly polarized state to the other, or maintaining the polarization state of the light; and a convergence / divergence element that is arranged downstream of the conversion element and converges either the right-handed circularly polarized light or the left-handed circularly polarized light, and diverges the other.

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

3. The eyeglass device according to claim 2, wherein the n convergence / divergence units are switchable between positive and negative eyeglass power.

4. The eyeglass device according to claim 2 or 3, wherein the n convergence / divergence units have different eyeglass powers.

5. The n convergence / divergence units include one convergence / divergence unit having a minimum eyeglass power and two convergence / divergence units having the minimum eyeglass power. ｍ and other "n-1" convergence / divergence units each having eyeglass powers corresponding to m times (m: integer, 1≦m≦n-1).

6. The eyeglass device according to any one of claims 2 to 5, wherein the minimum eyeglass power of the n convergence / divergence units is 0.25 or less.

7. An eyeglass device according to any one of claims 2 to 6, further comprising a receiving unit that receives an input for switching between convergence and divergence of light of the n converging / diverging units, and switches between convergence and divergence of light of the n converging / diverging units based on the switching input.

8. The eyewear device according to claim 7, wherein the reception unit is a switch unit that receives an input from a user, or a communication unit that receives a signal from an external device.

9. Controlling the plurality of conversion elements to convert the eyeglasses power of the eyeglasses device into two ｎ The eyewear device according to claim 2, further comprising a step-switchable control unit.

10. An eyeglass device according to any one of claims 2 to 9, further comprising a polarization blocking unit arranged downstream of the plurality of converging / diverging units and blocking the right-handed circularly polarized light or the left-handed circularly polarized light, the polarization blocking unit having: a second conversion element capable of switching between converting the polarization state of light from one of the right-handed circularly polarized state and the left-handed circularly polarized state to the other, or maintaining the polarization state of the light; and a second polarizing element that blocks the right-handed circularly polarized light or the left-handed circularly polarized light contained in the light output from the second conversion element.

11. The eyeglass device according to claim 10, further comprising a control unit, wherein the converging / diverging element converts light of one of the right-handed and left-handed circularly polarized states into light of the other polarized state and converges it, and converts the light of the other polarized state into light of the one polarized state and diverges it, and the control unit controls the multiple converging / diverging units and the polarization blocking unit so that when a final-stage converging / diverging unit of the multi-stage converging / diverging units converges the light of the one polarized state, the polarization blocking unit blocks the light of the one polarized state, and when the final-stage converging / diverging unit diverges the light of the other polarized state, the polarization blocking unit blocks the light of the other polarized state.

12. The eyeglass device according to any one of claims 2 to 11, further comprising a second converging / diverging element disposed between the polarizing element and the plurality of converging / diverging units.

13. The eyeglass device according to any one of claims 2 to 12, further comprising an optical lens disposed before, after or between the polarizing element and the plurality of converging / diverging units.

14. The eyeglass device according to claim 13, wherein the optical lens is made of an optical material whose refractive index decreases as the wavelength increases in the visible light wavelength range.

15. The eyeglass device according to any one of claims 1 to 14, wherein the plurality of converging / diverging units have a pair of portions each corresponding to a pair of human eyes, the pair of portions each having 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.

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