JP5359829B2 - Liquid crystal lenses and variable focal length glasses using them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bright liquid crystal lens having a high response speed, and variable in a focal length thereof. <P>SOLUTION: A first transparent electrode 103 is formed on a first curved transparent substrate 101, and a second transparent electrode 104 is formed on a second curved transparent substrate 102 in the same manner. The first and the second transparent substrates 101 and 102 are superposed on each other while interposing an insulating spacer 105 therebetween. A blue phase liquid crystal is sealed into a enclosure in between the first and the second transparent substrates 101 and 102 to form a liquid crystal layer 106. In the liquid crystal lens, the focal length (f) of the liquid crystal lens 100 is varied by controlling a voltage applied to the first and the second transparent electrodes 103 and 104, and then, changing the strength of the electric field formed in the liquid crystal layer 106. The liquid crystal lens 100 uses the blue phase liquid crystal, and accordingly, it is unnecessary to use the polarization effect and to use a polarization plate therein, then, the bright lens having higher response speed is provided. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention relates to a liquid crystal lens, in particular a liquid crystal lens using a blue phase liquid crystal, relates to variable focal length eyeglass using the same.

  For example, Patent Document 1 discloses a liquid crystal lens having a configuration in which liquid crystal molecules are sandwiched between a pair of transparent substrates on which transparent electrodes facing each other are formed. Such a liquid crystal lens makes use of the fact that the orientation gradually changes depending on the position of the liquid crystal molecules by forming a non-uniform electric field in the nematic liquid crystal layer sandwiched between the transparent electrodes. The distance to the focal point where the light incident on the lens is connected can be changed.

  By the way, in recent years, a liquid crystal called a blue phase liquid crystal has attracted attention. This blue phase liquid crystal is optically isotropic in the absence of an electric field, and exhibits birefringence when an electric field is applied. The blue phase liquid crystal is thought to be formed by the spiral axis of chiral nematic liquid crystal forming a three-dimensional lattice. By forming an electric field there, local molecular reorientation, lattice distortion, and phase transition to the nematic phase One of these occurs. For this reason, what is optically isotropic when no electric field is formed exhibits birefringence when the electric field is formed. Furthermore, the response time of the orientation change of the blue phase liquid crystal is about 1 millisecond or less.

JP 2005-128518 A

  Since the conventional liquid crystal lens utilizes birefringence due to liquid crystal molecules, the lens effect can be exerted only for extraordinary light. Therefore, the conventional liquid crystal lens needs to be provided with a polarizing plate, and does not function as a lens unless polarized input light is used. Therefore, only a half or less of the light amount can be effectively used for non-polarized input light. Further, the response time of the alignment change of the conventional nematic liquid crystal layer is about several tens of milliseconds.

Accordingly, an object of the present invention is to provide a liquid crystal lens that can change the focal length and is bright and has a high response speed. Further, using the liquid crystal lens, and an object thereof is to provide a variable focal length eyeglass.

To achieve the above object, according to one aspect of the liquid crystal lens of the present invention, a first transparent substrate, a first transparent electrode formed on the first transparent substrate, and the first transparent electrode are formed. A second transparent substrate facing the first transparent substrate on the surface side, a second transparent electrode formed on the surface of the first transparent substrate on the second transparent substrate, A third transparent electrode formed on a surface of the second transparent substrate opposite to the surface on the first transparent substrate side, and the third transparent electrode on the side of the surface on which the third transparent electrode is formed. A third transparent substrate facing the second transparent substrate, a fourth transparent electrode formed on the surface of the second transparent substrate on the third transparent substrate, the first transparent electrode, It is sandwiched between the second transparent electrode, when there is no voltage difference between the first transparent electrode and the second transparent electrode Histological to express isotropic, express birefringence when there is a voltage difference between the first transparent electrode and the second transparent electrode, blue phase liquid crystal or a polymer-stabilized blue A voltage difference between the third transparent electrode and the fourth transparent electrode, sandwiched between the first liquid crystal layer formed of phase liquid crystal , the third transparent electrode, and the fourth transparent electrode. The blue phase liquid crystal that is optically isotropic when there is no light and exhibits birefringence when there is a voltage difference between the third transparent electrode and the fourth transparent electrode Or a second liquid crystal layer formed of the polymer-stabilized blue phase liquid crystal, and the surface of the first transparent substrate on which the first transparent electrode is formed is a concave surface, The surface of the first transparent substrate opposite to the surface on which the first transparent electrode is formed is a convex surface, and the second The surface of the transparent substrate on which the second transparent electrode is formed is a concave surface, and the surface of the second transparent substrate opposite to the surface on which the second transparent electrode is formed is a convex surface. The first liquid crystal layer has a convex lens shape, the first liquid crystal lens portion and the surface of the second transparent substrate on which the third transparent electrode is formed are convex surfaces, and the second liquid crystal layer is a convex surface. The surface of the transparent substrate opposite to the surface on which the third transparent electrode is formed is a concave surface, and the surface of the third transparent substrate on the side on which the fourth transparent electrode is formed is a convex surface. A surface of the third transparent substrate opposite to the surface on which the fourth transparent electrode is formed is a concave surface, and the second liquid crystal layer has a concave lens shape; The voltage applied to the first transparent electrode and the second transparent electrode of the first liquid crystal lens unit is controlled. , Controlling the electric field formed in the first liquid crystal layer, controlling the voltage applied to the third transparent electrode and the fourth transparent electrode of the second liquid crystal lens unit, Voltage control means for controlling an electric field formed in the liquid crystal layer, wherein the first liquid crystal lens unit and the second liquid crystal lens unit are configured to overlap each other, and the first liquid crystal lens unit The first optical axis of the second liquid crystal lens unit and the second optical axis of the second liquid crystal lens unit coincide with each other .

Also, one aspect of the variable focal length glasses using the liquid crystal lens of the present invention is the target for setting the target focal length of the liquid crystal lens based on the measurement result of the liquid crystal lens, the distance measurement means, and the distance measurement means. A focal length setting unit, wherein the voltage control unit controls an electric field formed in the first liquid crystal layer and the second liquid crystal layer based on the target focal length, and the liquid crystal lens It is used as a lens for spectacles.

According to the present invention, by using a blue phase liquid crystal as a liquid crystal lens, it is possible to provide a bright liquid crystal lens that can change a focal length and has a quick response speed. Furthermore, it is possible to provide a variable focal length eyeglass using the liquid crystal lens.

The figure which shows an example of a structure of the liquid crystal lens which concerns on each embodiment of this invention. The figure explaining the change of the focal distance of the liquid crystal lens which concerns on each embodiment of this invention. The figure which shows another example of a structure of the liquid crystal lens which concerns on each embodiment of this invention. The figure explaining the change of the focal distance of the liquid crystal lens which concerns on each embodiment of this invention. The figure which shows another example of a structure of the liquid crystal lens which concerns on each embodiment of this invention. The figure which shows an example of a structure of the focal distance variable glasses using the liquid crystal lens based on the 4th Embodiment of this invention. The block diagram which shows an example of the structure of the control system of the focal distance variable glasses using the liquid crystal lens based on the 4th Embodiment of this invention. The figure which shows an example of a structure of the optical pick-up apparatus using the liquid crystal lens based on the 5th Embodiment of this invention. The figure which shows an example of a structure of the optical switch using the liquid crystal lens based on the 6th Embodiment of this invention. The figure which shows an example of a structure of the liquid-crystal lens array based on the 7th Embodiment of this invention. The figure which shows an example of a structure of the three-dimensional display apparatus using the liquid-crystal lens array based on the 8th Embodiment of this invention. The figure which shows an example of the structure of the directivity control liquid crystal display using a liquid crystal lens array based on the 9th Embodiment of this invention, and the outline of the directivity of the light by a liquid crystal lens array. The figure which shows an example of the structure of the directivity control liquid crystal display using a liquid crystal lens array based on the 9th Embodiment of this invention, and the outline of the directivity of the light by a liquid crystal lens array.

[First Embodiment]
First, a first embodiment of the present invention will be described with reference to the drawings. First, the structure of the liquid crystal lens 100 according to the present embodiment is shown in FIG. As shown in this figure, the liquid crystal lens 100 includes a first transparent substrate 101, a second transparent substrate 102, a first transparent electrode 103, a second transparent electrode 104, an insulating spacer 105, A liquid crystal layer 106.

  On the first transparent substrate 101 which is a curved transparent substrate such as a glass substrate, a first transparent electrode 103 made of a transparent conductive film such as an indium tin oxide (ITO) film is formed. Similarly, a second transparent electrode 104 such as an ITO film is formed on a second transparent substrate 102 such as a curved glass substrate. The first transparent substrate 101 and the second transparent substrate 102 have an insulating spacer so that the surface on which the first transparent electrode 103 is formed faces the surface on which the second transparent electrode 104 is formed. 105 are stacked. The first transparent substrate 101, the second transparent substrate 102, and the insulating spacer 105 form a convex lens-shaped hollow, and the first transparent substrate 101, the second transparent substrate 102, and the insulating spacer 105 The outer shape of the container formed is also a convex lens shape. Liquid crystal is sealed in the hollow of the convex lens type to form a liquid crystal layer 106.

  A liquid crystal called a blue phase liquid crystal is used as the liquid crystal forming the liquid crystal layer 106 of the present liquid crystal lens. The blue phase liquid crystal is thought to have a spiral axis of chiral nematic liquid crystal forming a three-dimensional lattice. Blue phase liquid crystals are optically isotropic when no electric field is formed. On the other hand, when an electric field is formed, any one of local molecular reorientation, lattice distortion, and phase transition to a nematic phase is generated, thereby expressing birefringence. The typical blue phase temperature range is very narrow. On the other hand, in recent years, a technology has been developed to form a thermally stable blue phase by mixing several to several tens of percent of a photopolymerized polymer in a liquid crystal and photopolymerizing the polymer in the temperature range of the blue phase. ing. The temperature range of the blue phase of such a liquid crystal stabilized blue phase liquid crystal is wider than the temperature range of a typical blue phase. The blue phase liquid crystal is also characterized in that the response speed for changing the orientation of the liquid crystal molecules is faster than that of the nematic liquid crystal. As the liquid crystal forming the liquid crystal layer 106, a typical blue phase liquid crystal may be used, or a polymer stabilized blue phase liquid crystal may be used.

  The first transparent electrode 103 and the second transparent electrode 104 are electrically connected to the applied voltage control unit 121. The applied voltage control unit 121 is connected to the power supply unit 122. The power supply unit 122 supplies power to the applied voltage control unit 121. The applied voltage control unit 121 controls the voltage applied to the first transparent electrode 103 and the second transparent electrode 104 and controls the electric field formed in the liquid crystal layer 106.

  Thus, for example, the first transparent substrate 101 functions as a first transparent substrate, for example, the first transparent electrode 103 functions as a first transparent electrode formed on the first transparent substrate, for example, The second transparent substrate 102 functions as a second transparent substrate facing the first transparent substrate. For example, the second transparent electrode 104 is formed on the surface on the first transparent substrate side on the second transparent substrate. For example, the liquid crystal layer 106 functions as a liquid crystal layer formed of blue phase liquid crystal. For example, the applied voltage control unit 121 applies a voltage applied to the first transparent electrode and the second transparent electrode. Functions as a voltage control means for controlling.

  Next, the operation of the present liquid crystal lens will be described. FIG. 2A schematically shows a path of light incident on the liquid crystal lens 100 when no electric field is formed in the liquid crystal layer 106. When no electric field is formed in the liquid crystal layer 106, the liquid crystal layer 106 is optically isotropic, so that incident light exhibits refraction depending on the shapes of the first transparent substrate 101 and the second transparent substrate 102. . On the other hand, FIG. 2B shows a schematic path of light incident on the liquid crystal lens when an electric field is formed in the liquid crystal layer 106.

The refractive index in the optical axis direction of the liquid crystal layer 106 when the electric field shown in FIG. 2A is not formed is N _off, and the light of the liquid crystal layer 106 when the electric field shown in FIG. 2B is formed. If the refractive index in the axial direction is N _on , generally N _off > N _on . Here, the refractive index N _on is to vary the intensity of the electric field formed in the liquid crystal layer 106.

Diopter D, which is the reciprocal of focal length f, is used as an amount representing the refractive power of the lens. When the radius of curvature inside the first transparent substrate 101 and the second transparent substrate 102 is R, the diopter D _off when no electric field is formed in the liquid crystal layer 106 is expressed by the following formula (1).

Here, f _off is a focal length f when no electric field is formed in the liquid crystal layer 106.

Similarly, the diopter D _on when an electric field is formed in the liquid crystal layer 106 is expressed by the following formula (2).

Here, f _on is a focal length f when an electric field is formed in the liquid crystal layer 106. Therefore, the focal length f is f _off <f _on when the refractive index is N _off > N _on .

ΔD, which is the difference between the diopter D when the electric field is formed in the liquid crystal layer 106 and when it is not, is expressed by the following formula (3).

Here, ΔN = N _on −N _off .

  As described above, the voltage applied to the first transparent electrode 103 and the second transparent electrode 104 is controlled by the applied voltage control unit 121 and the intensity of the electric field formed in the liquid crystal layer 106 is changed, so that the liquid crystal lens The focal length f of 100 can be changed.

  In the description with reference to FIG. 2, the case where the container formed by the first transparent substrate 101, the second transparent substrate 102, and the insulating spacer 105 has a convex lens shape has been described. Similar effects can be obtained when the shape of the mold is adopted. However, in the case of the concave lens type, the value of the diopter D is defined as a negative number.

  According to the present embodiment, the liquid crystal lens 100 can change the focal length by controlling the voltage applied to the first transparent electrode 103 and the second transparent electrode 104. Furthermore, since the blue phase liquid crystal is used as the liquid crystal forming the liquid crystal layer 106 of the liquid crystal lens 100 according to the present embodiment, it is not necessary to use polarized light. Therefore, since a polarizing plate is not used, a bright lens can be realized. Even when the light source is polarized in advance, the liquid crystal lens 100 exhibits the effect of the lens regardless of the direction of the polarization plane. Further, the liquid crystal lens 100 using the blue phase liquid crystal is characterized in that the response speed is faster than the liquid crystal lens using the nematic liquid crystal.

[Second Embodiment]
Next, a second embodiment of the present invention will be described. Here, in the description of the present embodiment, differences from the first embodiment will be described, the same parts as those in the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted. The liquid crystal lens 200 according to the present embodiment is a combination of the convex liquid crystal lens and the concave liquid crystal lens according to the first embodiment.

  As shown in FIG. 3, the liquid crystal lens 200 includes a first transparent substrate 201 that is a curved transparent substrate such as a glass substrate, a second transparent substrate 202, and a third transparent substrate 203. A first transparent electrode 204 made of a transparent conductive film such as an ITO film is formed on the concave surface side of the first transparent substrate 201. Similarly, a fourth transparent electrode 207 such as an ITO film is formed on the convex surface side of the third transparent substrate 203. A second transparent electrode 205 such as an ITO film is formed on the concave surface side of the second transparent substrate 202, and a third film such as an ITO film is formed on the convex surface side of the second transparent substrate 202. The transparent electrode 206 is formed.

  Then, the first transparent substrate 201 and the second transparent substrate 202 are bonded to each other with the first insulating spacer 208 interposed therebetween so that the first transparent electrode 204 and the second transparent electrode 205 face each other. . Further, the second transparent substrate 202 and the third transparent substrate 203 are bonded with the second insulating spacer 209 interposed therebetween so that the third transparent electrode 206 and the fourth transparent electrode 207 face each other. .

  In a space formed between the first transparent substrate 201 and the second transparent substrate 202, blue phase liquid crystal is sealed to form a first liquid crystal layer 210. A blue liquid crystal is enclosed in a space formed between the second transparent substrate 202 and the third transparent substrate 203 to form a second liquid crystal layer 211.

  Here, the curvature radii of the first transparent substrate 201, the second transparent substrate 202, and the third transparent substrate 203 are all R. Therefore, the liquid crystal lens 200 configured as described above is optically isotropic when no electric field is formed in the first liquid crystal layer 210 and the second liquid crystal layer 211.

  The first transparent electrode 204, the second transparent electrode 205, the third transparent electrode 206, and the fourth transparent electrode 207 are each electrically connected to the applied voltage control unit 121. The applied voltage control unit 121 is connected to the power supply unit 122. The power supply unit 122 supplies power to the applied voltage control unit 121. The applied voltage control unit 121 controls the voltage applied to the first transparent electrode 204, the second transparent electrode 205, the third transparent electrode 206, and the fourth transparent electrode 207, and controls the first liquid crystal layer 210 and The electric field formed in the second liquid crystal layer 211 is controlled.

  Thus, for example, the second transparent substrate 202 is a single transparent substrate in which two liquid crystal lenses are superposed on each other in a liquid crystal lens formed by superimposing two liquid crystal lenses. Function.

  Next, the operation of the liquid crystal lens 200 according to this embodiment will be described. FIG. 4 shows an outline of the path of light incident on the liquid crystal lens 200 when an electric field is formed or not formed on each liquid crystal layer of the liquid crystal lens 200. FIG. 4A shows an optical path of incident light when an electric field is not formed in the first liquid crystal layer 210 but an electric field is formed in the second liquid crystal layer 211. FIG. 4B shows an optical path of incident light when no electric field is formed in the first liquid crystal layer 210 and the second liquid crystal layer 211. FIG. 4C shows an optical path of incident light when an electric field is formed in the first liquid crystal layer 210 and no electric field is formed in the second liquid crystal layer 211.

In the case shown in FIG. 4B, the synthesized diopter D _{off, off} is the shape of the liquid crystal lens 200 because the first liquid crystal layer 210 and the second liquid crystal layer 211 do not have birefringence. _Therefore , D _{off, off} = 0.

On the other hand, the diopter D _{off, on in the} case shown in FIG. 4A is expressed by the following formula (4), and the liquid crystal lens 200 functions as a convex lens.

Similarly, the diopter D _{on, off in the} case shown in FIG. 4C is expressed by the following equation (5), and the liquid crystal lens 200 functions as a concave lens.

  That is, the focal length of the liquid crystal lens 200 can be changed continuously in the range where the diopter D is ± 2ΔN / R. In the description of the present embodiment, since it is assumed that the curvature radii of the curved surfaces of the first transparent substrate 201, the second transparent substrate 202, and the third transparent substrate 203 are all equal to R, the synthesized diopter D is 0. Although the control range is determined at the center, by appropriately designing the curvature radii of the curved surfaces of the first transparent substrate 201, the second transparent substrate 202, and the third transparent substrate 203, the control center value is shifted. It can also be set.

  According to the present embodiment, the liquid crystal lens 200 can change the focal length to a wider range as compared with the liquid crystal lens 100 of the first embodiment. Further, as in the first embodiment, since the liquid crystal lens 200 according to this embodiment uses a blue phase liquid crystal, it is not necessary to use polarized light. Therefore, since a polarizing plate is not used, a bright lens can be realized. Further, even when the light source is polarized in advance, the liquid crystal lens 200 exhibits the lens effect regardless of the direction of the polarization plane. Further, the liquid crystal lens 200 using a blue phase liquid crystal is characterized in that the response speed is faster than a liquid crystal lens using a nematic liquid crystal.

[Third Embodiment]
Next, a third embodiment of the present invention will be described. Here, in the description of the present embodiment, differences from the first embodiment will be described, the same parts as those in the first embodiment will be denoted by the same reference numerals, and description thereof will be omitted.

  The liquid crystal lens 310 according to the present embodiment has a configuration as shown in FIG. That is, for example, a first transparent electrode 312 made of a transparent conductive film such as an ITO film is formed on an insulating first transparent substrate 311 such as a glass substrate. In addition, the insulating second transparent substrate 313 such as a glass substrate is provided with a depression having a concave lens-like curved surface on one surface and a second conductive film made of a transparent conductive film such as an ITO film on the other surface. Two transparent electrodes 314 are formed.

  The surface of the first transparent substrate 311 where the first transparent electrode 312 is formed and the surface where the recess of the second transparent substrate 313 is provided are bonded together, and the recess of the second transparent substrate 313 is bonded. The liquid crystal layer 315 having a convex lens shape is formed by enclosing the blue phase liquid crystal in the space formed by the above. The first transparent electrode 312 and the second transparent electrode 314 are connected to an applied voltage control unit similar to the applied voltage control unit 121 (not shown).

Thus, for example, the first transparent substrate 311 functions as a first transparent substrate, for example, the first transparent electrode 312 functions as a first transparent electrode formed on the first transparent substrate, for example, the first transparent substrate 311 the second transparent substrate 313 functions as a second transparent substrate having a recess of concave shape on the first transparent substrate, for example, a second transparent electrode 314 surface having a recess of the concave shape of the second transparent substrate For example, the liquid crystal layer 315 functions as a liquid crystal layer formed of a blue phase liquid crystal sealed in a concave lens-shaped depression. For example, the applied voltage control unit 121 and the liquid crystal layer 315 function as a second transparent electrode. A similar applied voltage control unit functions as voltage control means for controlling the voltage applied to the first transparent electrode and the second transparent electrode.

  The liquid crystal lens 320 according to the present embodiment has a configuration as shown in FIG. That is, for example, a first transparent electrode 322 made of a transparent conductive film such as an ITO film is formed on an insulating first transparent substrate 321 such as a glass substrate. A convex lens-like structure 323 made of a transparent structure such as glass is bonded onto the first transparent electrode 322. Further, a second transparent electrode 325 made of a transparent conductive film such as an ITO film is formed on an insulating second transparent substrate 324 such as a glass substrate.

  The first transparent substrate 321 and the second transparent substrate 324 are bonded to each other so that the first transparent electrode 322 and the second transparent electrode 325 are opposed to each other and maintained at a constant interval by an insulating spacer (not shown). Yes. Then, blue phase liquid crystal is sealed in the formed gap, and a concave lens-shaped liquid crystal layer 326 is formed. Further, the first transparent electrode 322 and the second transparent electrode 325 are connected to an applied voltage control unit similar to the applied voltage control unit 121 not shown.

  Thus, for example, the convex lens-like structure 323 functions as a convex lens-shaped transparent member present in the liquid crystal layer.

  The liquid crystal lens 330 according to the present embodiment has a configuration as shown in FIG. That is, for example, a first transparent electrode 332 made of a transparent conductive film such as an ITO film is formed on an insulating first transparent substrate 331 such as a glass substrate. In addition, the insulating second transparent substrate 333 such as a glass substrate is provided with a depression having a prism shape on one surface, and the second surface made of a transparent conductive film such as an ITO film on the other surface. A transparent electrode 334 is formed.

  The surface of the first transparent substrate 331 on which the first transparent electrode 332 is formed and the surface on which the recess of the second transparent substrate 333 is provided are bonded together, and the recess of the second transparent substrate 333 is bonded. A blue phase liquid crystal is sealed in the space formed by the above, and a prism-shaped liquid crystal layer 335 is formed. The first transparent electrode 332 and the second transparent electrode 334 are connected to an applied voltage control unit similar to the applied voltage control unit 121 (not shown).

Thus, for example, the first transparent substrate 331 functions as a first transparent substrate, for example, the first transparent electrode 332 functions as a first transparent electrode formed on the first transparent substrate, for example, the first transparent substrate the second transparent substrate 333 functions as a second transparent substrate having a recess of prisms on the first transparent substrate, for example, a second transparent electrode 334 surface having a recess of the prism shape of the second transparent substrate For example, the liquid crystal layer 335 functions as a liquid crystal layer formed of blue phase liquid crystal sealed in a prism-shaped depression, and for example, the applied voltage control unit 121 and A similar applied voltage control unit functions as voltage control means for controlling the voltage applied to the first transparent electrode and the second transparent electrode.

  The liquid crystal lens 340 according to the present embodiment has a configuration as shown in FIG. In other words, a first transparent electrode 342 made of a transparent conductive film such as an ITO film is formed on an insulating first transparent substrate 341 such as a glass substrate. A prismatic structure 343 made of a transparent structure such as glass is bonded onto the first transparent electrode 342. Further, a second transparent electrode 345 made of a transparent conductive film such as an ITO film is formed on an insulating second transparent substrate 344 such as a glass substrate.

  The first transparent substrate 341 and the second transparent substrate 344 are bonded to each other so that the first transparent electrode 342 and the second transparent electrode 345 are opposed to each other and maintained at a constant interval by an insulating spacer (not shown). Yes. Then, blue phase liquid crystal is sealed in the formed gap, and a liquid crystal layer 346 is formed. The first transparent electrode 342 and the second transparent electrode 345 are connected to an applied voltage control unit similar to the applied voltage control unit 121 (not shown).

  Thus, for example, the prismatic structure 343 functions as a prism-shaped transparent member in the liquid crystal layer.

Next, the operation of the liquid crystal lens 310 according to this embodiment will be described. The lens effect of the liquid crystal lens 310 is that the refractive index N _{g of} the second transparent substrate 313, the refractive index N on of the liquid crystal layer 315 when an electric field is formed in the liquid crystal layer 315, and the electric field _on the liquid crystal layer 315. It is determined by the relationship with the refractive index N _off of the liquid crystal layer 315 when it is not formed. In the case of N _g <N _on <N _off , the liquid crystal lens 310 functions as a convex lens. Further, when N _on <N _off <N _g , the liquid crystal lens 310 functions as a concave lens. When N _on <N _g <N _off , the liquid crystal lens 310 functions as a concave / convex lens. In any case, the liquid crystal lens 310 can change the focal length by the voltage applied to the first transparent electrode 312 and the second transparent electrode 314.

Next, the operation of the liquid crystal lens 320 according to this embodiment will be described. Also the lens effect of the liquid crystal lens 320, forming a refractive index _{N g} of the convex lens structure 323, the refractive index _{N on} the liquid crystal layer 326 when the liquid crystal layer 326 to form an electric field, an electric field to the liquid crystal layer 326 It is determined by the relationship with the refractive index N _off of the liquid crystal layer 326 when it is not. In the case of N _on <N _off <N _g , the liquid crystal lens 320 functions as a convex lens. Further, when N _g <N _on <N _off , the liquid crystal lens 320 functions as a concave lens. In the case of N _on <N _g <N _off , the liquid crystal lens 320 functions as a concave / convex lens. In any case, the liquid crystal lens 320 can change the focal length by the voltage applied to the first transparent electrode 322 and the second transparent electrode 325.

  The operations of the liquid crystal lens 330 and the liquid crystal lens 340 are the same as those of the liquid crystal lens 310 and the liquid crystal lens 320, respectively, and the first transparent electrode 332 and the second transparent electrode 334, or the first transparent electrode 342 and the second transparent electrode. The refractive index of the liquid crystal layer 335 or the liquid crystal layer 346 can be changed by a voltage applied to the electrode 345. Therefore, by controlling the change in the refractive index, the light emission direction can be controlled.

  According to the present embodiment, the liquid crystal lens 310 and the liquid crystal lens 320 are variable focal length lenses that change the focal length, like the liquid crystal lens 100 of the first embodiment and the liquid crystal lens 200 of the second embodiment. Function. Further, the liquid crystal lens 330 and the liquid crystal lens 340 function as optical elements that change the light emission direction. In addition, since the blue phase liquid crystal is used as in the first embodiment, it is not necessary to use polarized light. Therefore, since a polarizing plate is not used, a bright lens can be realized. Even when the light source is polarized in advance, the liquid crystal lens exhibits the effect of the lens regardless of the direction of the polarization plane. Further, the liquid crystal lens using the blue phase liquid crystal is characterized in that the response speed is faster than the liquid crystal lens using the nematic liquid crystal.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to the drawings. The present embodiment is a variable focal length glasses 400 using the liquid crystal lens 100, the liquid crystal lens 200, the liquid crystal lens 310, or the liquid crystal lens 320.

  As shown in FIGS. 6 and 7, the variable focal length glasses 400 according to the present embodiment include a liquid crystal lens 401 and a distance measuring sensor 402. In addition, a main body 406 including a control unit 403, a power supply unit 404, and a user information recording unit 405 is provided. The control unit 403 includes a ranging sensor control unit 407 and an applied voltage control unit 408. The liquid crystal lens 401 is the liquid crystal lens 100 of the first embodiment, the liquid crystal lens 200 of the second embodiment, the liquid crystal lens 310 of the third embodiment, or the liquid crystal lens 320 of the third embodiment. The control unit 408 is the same as the applied voltage control unit 121 in the first embodiment and the like. Therefore, these descriptions are omitted.

  The distance measuring sensor 402 is, for example, a known infrared irradiation type distance measuring sensor. The distance measurement sensor control unit 407 controls the operation of the distance measurement sensor 402, calculates distance measurement, and the like. The control unit 403 determines the target focal length of the liquid crystal lens 401 based on the measurement result calculated by the ranging sensor control unit 407 and sends it to the applied voltage control unit 408. The applied voltage control unit 408 sets the focal length of the liquid crystal lens 401 based on the target focal length of the liquid crystal lens 401 input from the control unit 403. The user information recording unit 405 records information on the visual acuity of the user of the focal length variable glasses.

  In this manner, for example, the distance measuring sensor 402 and the distance measuring sensor control unit 407 function as a distance measuring unit, and for example, the control unit 403 serves as a target focal length setting unit that sets a target focal length based on the measurement result of the distance measuring unit. For example, the user information recording unit 405 functions as a user information recording unit that records the user's visual acuity information.

  Next, the operation of the variable focal length glasses according to this embodiment will be described. If the distance measuring sensor 402 is controlled by the distance measuring sensor control unit 407, for example, if it is an infrared irradiation type distance measuring sensor, it irradiates infrared rays, receives reflected light, and sends a received light signal to the distance measuring sensor control unit 407 Output. The distance measurement sensor control unit 407 calculates the distance between the distance measurement sensor 402 and the object, for example, an object reflecting infrared rays, based on the light reception signal input from the distance measurement sensor 402. The distance sensor control unit 407 outputs the calculated distance between the object and the distance sensor 402 to the control unit 403.

  The control unit 403 determines a target focal length that is a target value of the focal length of the liquid crystal lens 401 based on the distance between the object input from the distance measurement sensor control unit 407 and the distance measurement sensor 402. At this time, information relating to the visual acuity of the user of the variable focal length glasses recorded in advance in the user information recording unit 405 is referred to. In the information on the user's visual acuity, for example, the focal length of the liquid crystal lens 401, which is optimal for correcting the user's visual acuity, is recorded according to the distance from the user to the observation object. As a result, the control unit 403, for example, corrects myopia of the user who has myopia and presbyopia when the distance from the user to the observation object is longer than a preset distance. When the target focal length is the focal length of the liquid crystal lens 401 that is optimal for the user, and the distance from the user to the observation object is shorter than a preset distance, the liquid crystal lens 401 that is optimal for correcting the presbyopia of the user. Is the target focal length.

  Here, an example in which two setting values are selected when the distance from the user to the observation object is longer than a preset distance and when the distance is shorter is described. However, three or more setting values are selected. Also good. Further, when the distance between the object input from the distance measuring sensor control unit 407 and the distance measuring sensor 402 changes one after another, if the focal length of the liquid crystal lens 401 is changed one after another accordingly, the user feels uncomfortable. Therefore, the focal length of the liquid crystal lens 401 may not be changed by a short-time change. For example, the control unit 403 may set the target focal length of the liquid crystal lens 401 as described above only when the user presses a setting switching button (not shown).

  When the control unit 403 determines the target focal length of the liquid crystal lens 401, the control unit 403 outputs it to the applied voltage control unit 408. The applied voltage control unit 408 determines and controls the voltage applied to each transparent electrode of the liquid crystal lens 401 based on the target focal length input from the control unit 403. As a result, the focal length of the liquid crystal lens 401 becomes the target focal length determined by the control unit 403 according to the distance from the user to the observation target detected by the distance measuring sensor 402.

  According to the variable focal length glasses 400 according to the present embodiment, the distance from the user to the observation object is measured by the distance measuring sensor 402, and the focal length of the liquid crystal lens 401 is automatically adjusted based on the information. it can. Further, when the focal length variable glasses 400 are used, if user information recorded in the user information recording unit 405 is rewritten, even if the user's visual acuity changes, the glasses can be changed without changing the glasses. Glasses having different focal lengths can be provided. Furthermore, in conventional bifocal glasses, a lens having a different focal length is realized by a single lens so that a part of the lens is used for correcting myopia and the other part is used for correcting presbyopia. For this reason, there is a limit to the field of view when using conventional bifocal glasses. On the other hand, the variable focal length glasses 400 according to the present embodiment can realize a plurality of focal lengths by changing the focal length of the entire lens surface, so that a wide field of view can be realized.

[Fifth Embodiment]
Next, an optical pickup device using the liquid crystal lens 100, the liquid crystal lens 200, the liquid crystal lens 310, or the liquid crystal lens 320 according to a fifth embodiment of the present invention will be described with reference to the drawings. FIG. 8 shows an outline of the optical pickup device 500 using the liquid crystal lens 100, the liquid crystal lens 200, the liquid crystal lens 310, or the liquid crystal lens 320. The optical pickup device 500 is a device that reads information recorded on a recording surface 511 of an optical disc 510 that is an optical recording medium. The optical pickup device 500 includes a displacement sensor 521 that is a known minute displacement measuring instrument, a laser light source 522 that is, for example, a semiconductor laser, a beam splitter 523, a known optical sensor 524, and a control unit 525. The optical pickup device 500 includes a liquid crystal lens 541 and an applied voltage control unit 542.

  The control unit 525 controls each unit of the optical pickup device 500. The liquid crystal lens 541 is the liquid crystal lens 100 of the first embodiment, the liquid crystal lens 200 of the second embodiment, the liquid crystal lens 310 of the third embodiment, or the liquid crystal lens 320 of the third embodiment. The control unit 542 is the same as the applied voltage control unit 121 in the first embodiment or the like. Therefore, these descriptions are omitted.

  Thus, for example, the displacement sensor 521 functions as a distance measuring unit, for example, the control unit 525 functions as a target focal length setting unit that sets a target focal length based on the measurement result of the distance measuring unit, and the laser light source 522, for example. For example, the liquid crystal lens 541 condenses the laser light generated from the laser light source on the recording surface of the optical disc and collects the laser light condensed on the recording surface of the optical disc. For example, the optical sensor 524 functions as a light receiving element that receives the reflected light from the recording surface of the optical disk.

  Next, the operation of the optical pickup device 500 according to this embodiment will be described. The optical disk 510 rotates at a high speed, and the recording surface 511 of the optical disk 510 is slightly displaced up and down. Therefore, the displacement sensor 521 measures a minute displacement of the optical disc 510. The measurement result of the displacement by the displacement sensor 521 is output to the control unit 525.

  Laser light emitted from the laser light source 522 enters the beam splitter 523 and travels toward the liquid crystal lens 541. At this time, the control unit 525 calculates the focal length of the liquid crystal lens 541 necessary for focusing the laser beam on the recording surface 511 of the optical disc 510 based on the displacement of the optical disc 510 input from the displacement sensor 521. To do. Then, the control unit 525 outputs the calculated focal length of the liquid crystal lens 541 to the applied voltage control unit 542. The applied voltage control unit 542 controls the voltage input to the liquid crystal lens 541 based on the focal length of the liquid crystal lens 541 input from the control unit 525.

  The laser beam converged by the liquid crystal lens 541 whose focal length is controlled as described above is focused on the recording surface 511 of the optical disc 510, and the reflected light is an optical sensor via the liquid crystal lens 541 and the beam splitter 523. Incident to 524. The optical sensor 524 outputs a light reception signal to the control unit 525. The control unit 525 acquires information recorded on the recording surface 511 based on the light reception signal input from the optical sensor 524. In the above description, reading of the optical disk has been described. Of course, writing can also be performed with the same configuration.

According to the optical pickup device 500 according to the present embodiment, the focal position of the laser beam for reading information can be adjusted at high speed in accordance with the displacement of the optical disc 510, thereby enabling accurate reading. At this time, the quick time response of the blue phase liquid crystal is effective. In addition, the wavelength of laser light used for an optical disc varies depending on the standard of the optical disc, such as an audio CD, a DVD, a Blu-ray Disc (BD) (registered trademark), or the like. In general, since there is chromatic dispersion in the refractive index of a lens, the focal lengths for light of different wavelengths are different. Therefore, in general, it is necessary to adjust the optical system according to the wavelength. However, if the liquid crystal lens of this embodiment is used, the focal length of the lens can be adjusted in accordance with the wavelength of the laser beam to be used by adjusting the voltage applied to the liquid crystal lens. Therefore, an optical system can be designed simply even in an apparatus that handles optical discs of a plurality of types of standards.

[Sixth Embodiment]
Next, an optical switch using the liquid crystal lens 330 or the liquid crystal lens 340 of the third embodiment according to the sixth embodiment of the present invention will be described with reference to the drawings. FIG. 9 is a conceptual diagram of the optical switch 600 using the liquid crystal lens 330 or the liquid crystal lens 340 of the third embodiment. The optical switch 600 includes a first input optical waveguide 601, a second input optical waveguide 602, a first output optical waveguide 603, a second output optical waveguide 604, a prism-like liquid crystal lens 611, and an application. Voltage control unit 612.

  The prism-shaped liquid crystal lens 611 is, for example, the liquid crystal lens 340 according to the third embodiment, and can control the optical path under the control of the applied voltage control unit 612. Here, the shape of the prism is different from that in FIG. 5D, but the essence is the same, and only the traveling direction of the light is described. Thus, the shape of the liquid crystal lens 611 can be set as appropriate depending on the shape of the optical switch 600. Here, the liquid crystal lens 611 is denoted by the same reference numeral as that in the third embodiment, and the description thereof is omitted.

  Next, the operation of the optical switch according to the present embodiment will be described. First, in a first state where no electric field is formed in the liquid crystal layer 346 of the liquid crystal lens 611, the incident light travels straight through the liquid crystal lens 611. Accordingly, light that has entered the liquid crystal lens 611 through the first input optical waveguide 601 travels straight through the liquid crystal lens 611 and is guided to the first output optical waveguide 603. Similarly, light that has entered the liquid crystal lens 611 through the second input optical waveguide 602 travels straight through the liquid crystal lens 611 and is guided to the second output optical waveguide 604.

  On the other hand, in the second state where an electric field is formed in the liquid crystal layer 346 of the liquid crystal lens 611, incident light is bent in the liquid crystal lens 611. Therefore, the light that has entered the liquid crystal lens 611 through the first input optical waveguide 601 is bent by the liquid crystal lens 611, guided to the second output optical waveguide 604, and passed through the second input optical waveguide 602 to be liquid crystal lens 611. The light incident on is bent by the liquid crystal lens 611 and guided to the first output optical waveguide 603.

  As described above, according to the present embodiment, by combining the prism-shaped liquid crystal lens 611 and the optical waveguide, a crossbar type optical switch that switches two sets of inputs and outputs can be manufactured.

  The above embodiment is an example. For example, in a first state where an electric field is not formed in the liquid crystal layer 346 of the liquid crystal lens 611, incident light is bent in the liquid crystal lens 611 and an electric field is formed in the liquid crystal layer 346. In the second state, the refractive indexes of the prismatic structure 343 and the liquid crystal layer 346 may be set so that incident light travels straight through the liquid crystal lens 611. Further, the input optical waveguide as an input is only the first input optical waveguide 601, and the light output is changed to the first output optical waveguide 603 by switching between the first state and the second state of the liquid crystal lens 611. Alternatively, it may be designed to switch to the second output optical waveguide 604. Further, the number of inputs / outputs is not limited to two, and three or more inputs / outputs may be switched.

[Seventh Embodiment]
Next, a liquid crystal lens array according to a seventh embodiment of the present invention in which the liquid crystal lenses according to the first to third embodiments are arranged in an array will be described with reference to the drawings. A liquid crystal lens array 710 shown in FIG. 10A is a liquid crystal lens array in which a large number of circular lenses are arranged in an array. The liquid crystal lens array 710 includes a first transparent substrate 711 on which a first transparent electrode (not shown) is formed, a second transparent electrode (not shown), and a large number of surfaces on which the second transparent electrode is not formed. A liquid crystal layer 713 is formed by pasting together a second transparent substrate 712 provided with a circular lens-shaped depression and encapsulating a blue phase liquid crystal in the circular lens-shaped depression.

  A liquid crystal lens array 720 shown in FIG. 10B is a liquid crystal lens array in which a large number of cylindrical lenses are arranged in an array. The liquid crystal lens array 720 includes a first transparent substrate 721 on which a first transparent electrode (not shown) is formed, a second transparent electrode (not shown), and a large number of surfaces on a surface where the second transparent electrode is not formed. A liquid crystal layer 723 is formed by pasting together a second transparent substrate 722 provided with a cylindrical surface-shaped depression and enclosing a blue phase liquid crystal in the cylindrical surface-shaped depression.

  A liquid crystal lens array 730 shown in FIG. 10C is a liquid crystal lens array in which a large number of pyramidal prisms are arranged in an array. The liquid crystal lens array 730 includes a first transparent substrate 731 on which a first transparent electrode (not shown) is formed, a second transparent electrode (not shown), and a large number of surfaces on the surface where the second transparent electrode is not formed. A liquid crystal layer 733 is formed by pasting together a second transparent substrate 732 provided with a pyramid-shaped depression and sealing a blue phase liquid crystal in the pyramid-shaped depression.

  A liquid crystal lens array 740 shown in FIG. 10D is a liquid crystal lens array in which a large number of triangular prisms are arranged in an array. The liquid crystal lens array 740 includes a first transparent substrate 741 on which a first transparent electrode (not shown) is formed, a second transparent electrode (not shown), and a large number on a surface on which the second transparent electrode is not formed. A liquid crystal layer 743 is formed by pasting together a second transparent substrate 742 provided with a triangular prism-shaped depression and enclosing a blue phase liquid crystal in the triangular prism-shaped depression.

In any liquid crystal lens array, by controlling the voltage applied to the first transparent electrode and the second transparent electrode, each circular lens shape and each cylindrical surface shape are the same as in the case of the third embodiment. The direction of light from the light source can be changed by refraction in each pyramid-shaped or triangular prism-shaped liquid crystal layer. Therefore, the entire liquid crystal lens array can electrically control the condensing property, diffusibility, and directivity of light from the light source.

  For example, in the liquid crystal lens array 710 illustrated in FIG. 10A, for example, the first transparent substrate 711 side is provided for each unit including one circular lens-shaped liquid crystal layer 713 by an electric field formed in the liquid crystal layer 713. The light incident on each unit can be converged or diffused. Similarly, in the liquid crystal lens array 730 shown in FIG. 10C, for example, on the side of the first transparent substrate 731 for each unit including one pyramid-shaped liquid crystal layer 733 by the electric field formed in the liquid crystal layer 733. The light incident on each unit can be converged or diffused.

  Further, in the liquid crystal lens array 720 shown in FIG. 10B, the light incident on the liquid crystal lens array 720 from the first transparent substrate 721 side by the electric field formed in the liquid crystal layer 723 is changed to that shown in FIG. Can be converged or diffused in the left-right direction. Similarly, in the liquid crystal lens array 740 shown in FIG. 10 (d), the light incident on the liquid crystal lens array 740 from the first transparent substrate 741 side by the electric field formed in the liquid crystal layer 743 is changed to that shown in FIG. ) In the left-right direction.

  In each liquid crystal lens array, the liquid crystal when light is incident on the liquid crystal lens array as described in the description of the third embodiment by appropriately setting the relationship between the refractive indexes of the transparent substrates and the liquid crystal layer. The relationship between the electric field formed in the layer and the convergence or diffusion of light can be set.

  The shape of the liquid crystal lens array described above is an example, and the same effect can be obtained in liquid crystal lens arrays having various shapes that change the traveling direction of light according to the application.

[Eighth Embodiment]
It will now be described with reference to the drawings attached to the three-dimensional display device that applies the liquid crystal lens array 740 of the seventh embodiment according to the eighth embodiment of the present invention. In general, the three-dimensional display device enables three-dimensional display by displaying right-eye image information on pixels observed with the right eye and left-eye image information on pixels observed with the left eye. That is, in order to display image information for one pixel, two pixels for the right eye and the left eye are required. For this reason, when a two-dimensional image is displayed on a conventional three-dimensional display device, the display pixel becomes one-half of the substantial number of pixels that the display device has, so that detailed information such as characters can be displayed. There is a problem that it is difficult. Therefore, the three-dimensional display device 800 according to the present embodiment uses the liquid crystal lens array 740 to switch between the three-dimensional display mode and the two-dimensional display mode, so that in the two-dimensional display mode, the right-eye pixel, By using the left-eye pixel, an image having the number of pixels twice the number of pixels in the three-dimensional display mode can be displayed.

  A three-dimensional display device 800 according to this embodiment includes a display panel 810 having a plurality of pixels 811, a liquid crystal lens array 820, and an applied voltage control unit 822. The liquid crystal lens array 820 is the liquid crystal lens array 740 according to the seventh embodiment. Here, the same reference numerals as those in the description of the seventh embodiment are given, and the configuration thereof will be described. The liquid crystal lens array 820 includes a first transparent substrate 741 on which a first transparent electrode 744 is formed and a second transparent substrate 742 on which a second transparent electrode 745 is formed. A large number of triangular prism-shaped depressions are provided on the surface of the second transparent substrate 742 where the second transparent electrode 745 is not formed. The surface of the first transparent substrate 741 on which the first transparent electrode 744 is formed and the surface of the second transparent substrate 742 on which the triangular prism-shaped recess is provided are bonded together, and the triangular prism-shaped recess Is filled with blue phase liquid crystal, and a liquid crystal layer 743 is formed.

  In this manner, for example, the display panel 810 is arranged on a plane and functions as a display surface that displays an image including a plurality of pixels that emit display light. For example, the liquid crystal lens array 820 is overlaid on the display surface. Further, it functions as a liquid crystal lens array that changes the optical path by controlling the electric field formed in the liquid crystal layer.

  Next, the operation of the three-dimensional display device 800 will be described. In the three-dimensional display device 800, the liquid crystal lens array 820 is turned off (two-dimensional display mode), that is, as shown by the broken line in FIG. In the case where the applied voltage is controlled so as not to exist, it functions in the same manner as a general two-dimensional display element. On the other hand, when the liquid crystal lens array 820 is turned on (three-dimensional display mode), that is, as shown by the solid line in FIG. 11, the applied voltage is controlled so that the light is refracted by the liquid crystal lens array 820. In this case, the image information for the right eye is displayed on the pixel observed with the right eye, and the image information for the left eye is displayed on the pixel observed with the left eye, thereby enabling three-dimensional display.

According to this embodiment, in the three-dimensional display mode, the right-eye pixel and the left-eye pixel are separately used to enable three-dimensional display, while in the two-dimensional display mode, the right-eye pixel, An image having the number of pixels twice the number of pixels in the three-dimensional display mode can be displayed using the left-eye pixels. Furthermore, by controlling the voltage applied to the liquid crystal lens array 820, there is a feature that the distance between the display device suitable for three-dimensional display that changes the refraction angle and the eyes can be varied. In addition, it is possible to switch between the three-dimensional display mode and the two-dimensional display mode at high speed by using the fast time response of the blue phase liquid crystal. Moreover, since the liquid crystal lens of this embodiment does not use polarized light, it can be used not only for liquid crystal displays but also for plasma displays and organic EL displays that do not use polarized light. At that time, the brightness of the display is not impaired.

[Ninth Embodiment]
Next, a directivity control liquid crystal display to which the liquid crystal lens array 740 of the seventh embodiment is applied according to the ninth embodiment of the present invention will be described with reference to the drawings. The directivity control liquid crystal display 900 of this embodiment includes a liquid crystal display panel 910, which is a general liquid crystal display element, a backlight 911, a liquid crystal lens array 920, and an applied voltage control, as shown in FIGS. 922, an illuminance sensor 923 that measures the brightness of the environment, and a controller 924 that controls the liquid crystal display panel 910.

  The liquid crystal lens array 920 is the liquid crystal lens array 740 according to the seventh embodiment. Here, the same reference numerals as those of the liquid crystal lens array 820 described in the eighth embodiment are given, and the description thereof is omitted.

  In this manner, for example, the liquid crystal display panel 910 functions as a light-transmissive display element that has a light source behind the display surface and emits display light representing an image from the display surface. For example, the liquid crystal lens array 920 includes a display element. And functions as a liquid crystal lens array that changes the directivity of the display light.

  Next, the operation of the directivity control liquid crystal display 900 will be described. The illuminance sensor 923 measures the brightness of the environment where the directivity control liquid crystal display 900 is installed. The illuminance sensor 923 outputs a measurement result signal to the control unit 924.

As described in the description of the seventh embodiment, the liquid crystal lens array 920 can electrically control the condensing property, diffusibility, and directivity of light from the light source. Therefore, if the brightness of the environment input from the illuminance sensor 923 is higher than a preset threshold, the control unit 924 displays the light from the backlight 911 as indicated by a dotted line at the top in FIGS. 12 and 13. In order to enhance the directivity, the applied voltage control unit 922 is commanded to control the electric field formed in the liquid crystal layer 743 of the liquid crystal lens array 920.

The applied voltage control unit 922 controls the electric field formed in the liquid crystal layer 743 of the liquid crystal lens array 920 based on a command from the control unit 924, and enhances the directivity of light from the backlight 911.

On the other hand, if the brightness of the environment input from the illuminance sensor 923 is lower than a preset threshold, the control unit 924 displays the light from the backlight 911 as indicated by a solid line at the top in FIGS. 12 and 13. In order to weaken the directivity, the applied voltage control unit 922 is instructed to control the electric field formed in the liquid crystal layer 743 of the liquid crystal lens array 920.

The applied voltage control unit 922 controls the electric field formed in the liquid crystal layer 743 of the liquid crystal lens array 920 based on a command from the control unit 924, and weakens the directivity of light from the backlight 911.

  As described above, for example, when used in bright sunny weather outdoors, the liquid crystal lens array 920 increases the directivity of the light from the backlight 911 as indicated by the dotted lines in the upper part of FIGS. Thereby, at the expense of the viewing angle of the display of the liquid crystal display panel 910, the front brightness can be increased and the visibility can be improved. On the other hand, when used in a dark environment, the directivity of the light from the backlight 911 is weakened as indicated by the solid line in the upper part of FIGS. Thereby, priority can be given to a viewing angle.

  As described above, according to the present embodiment, it is possible to provide the directivity control liquid crystal display 900 that can be used by changing the display state according to the use environment.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, the problem described in the column of problems to be solved by the invention can be solved and the effect of the invention can be obtained. The configuration in which this component is deleted can also be extracted as an invention. Furthermore, constituent elements over different embodiments may be appropriately combined.

  DESCRIPTION OF SYMBOLS 100 ... Liquid crystal lens, 101 ... 1st transparent substrate, 102 ... 2nd transparent substrate, 103 ... 1st transparent electrode, 104 ... 2nd transparent electrode, 105 ... Insulating spacer, 106 ... Liquid crystal layer, 121 ... Applied voltage control unit, 122 ... power supply unit, 200 ... liquid crystal lens, 201 ... first transparent substrate, 202 ... second transparent substrate, 203 ... third transparent substrate, 204 ... first transparent electrode, 205 ... first 2 transparent electrodes, 206 ... third transparent electrode, 207 ... fourth transparent electrode, 208 ... first insulating spacer, 209 ... second insulating spacer, 210 ... first liquid crystal layer, 211 ... first 2 liquid crystal layers, 310 ... liquid crystal lens, 311 ... first transparent substrate, 312 ... first transparent electrode, 313 ... second transparent substrate, 314 ... second transparent electrode, 315 ... liquid crystal layer, 320 ... liquid crystal Lens, 321... First transparent substrate, 3 2 ... 1st transparent electrode, 323 ... Convex lens-like structure, 324 ... 2nd transparent substrate, 325 ... 2nd transparent electrode, 326 ... Liquid crystal layer, 330 ... Liquid crystal lens, 331 ... 1st transparent substrate, 332 ... 1st transparent electrode, 333 ... 2nd transparent substrate, 334 ... 2nd transparent electrode, 335 ... Liquid crystal layer, 340 ... Liquid crystal lens, 341 ... 1st transparent substrate, 342 ... 1st transparent electrode, 343 ... prismatic structure, 344 ... second transparent substrate, 345 ... second transparent electrode, 346 ... liquid crystal layer, 400 ... variable focal length glasses, 401 ... liquid crystal lens, 402 ... distance measuring sensor, 403 ... control unit, 404 ... Power source unit, 405 ... User information recording unit, 406 ... Main body unit, 407 ... Ranging sensor control unit, 408 ... Applied voltage control unit, 500 ... Optical pickup device, 510 ... Optical disc, 511 ... Recording surface, 521 ... Strange Sensors 522 ... Laser light source 523 ... Beam splitter 524 ... Optical sensor 525 ... Control unit 541 ... Liquid crystal lens 542 ... Applied voltage control unit 600 ... Optical switch 601 ... First input optical waveguide 602 ... Second input optical waveguide, 603 ... first output optical waveguide, 604 ... second output optical waveguide, 611 ... liquid crystal lens, 612 ... applied voltage control unit, 710 ... liquid crystal lens array, 711 ... first transparent substrate 712 ... second transparent substrate, 713 ... liquid crystal layer, 720 ... liquid crystal lens array, 721 ... first transparent substrate, 722 ... second transparent substrate, 723 ... liquid crystal layer, 730 ... liquid crystal lens array, 731 ... first. 1 transparent substrate, 732 ... second transparent substrate, 733 ... liquid crystal layer, 740 ... liquid crystal lens array, 741 ... first transparent substrate, 742 ... second transparent substrate, 743 ... liquid crystal Layer 744 ... 1st transparent electrode, 745 ... 2nd transparent electrode, 800 ... 3D display device, 811 ... Pixel, 810 ... Display panel, 820 ... Liquid crystal lens array, 822 ... Applied voltage controller, 900 ... 3 Dimensional display device, 910 ... liquid crystal display panel, 911 ... backlight, 920 ... liquid crystal lens array, 922 ... applied voltage control unit, 923 ... illuminance sensor, 924 ... control unit.

Claims (4)

A first transparent substrate;
A first transparent electrode formed on the first transparent substrate;
A second transparent substrate facing the first transparent substrate on the side where the first transparent electrode is formed;
A second transparent electrode formed on a surface on the first transparent substrate side on the second transparent substrate;
A third transparent electrode formed on a surface opposite to the surface on the first transparent substrate side on the second transparent substrate;
A third transparent substrate facing the second transparent substrate on the side on which the third transparent electrode is formed;
A fourth transparent electrode formed on the second transparent substrate side surface on the third transparent substrate;
Optically isotropic when there is no voltage difference between the first transparent electrode and the second transparent electrode between the first transparent electrode and the second transparent electrode In addition, when there is a voltage difference between the first transparent electrode and the second transparent electrode, the first phase is formed by blue phase liquid crystal or polymer stabilized blue phase liquid crystal that exhibits birefringence . and a liquid crystal layer of,
Optically isotropic when there is no voltage difference between the third transparent electrode and the fourth transparent electrode between the third transparent electrode and the fourth transparent electrode. In addition, when there is a voltage difference between the third transparent electrode and the fourth transparent electrode, the blue phase liquid crystal or the polymer stabilized blue phase liquid crystal that exhibits birefringence is formed. A second liquid crystal layer;
Have
The surface of the first transparent substrate on which the first transparent electrode is formed is a concave surface, and the surface of the first transparent substrate opposite to the surface on which the first transparent electrode is formed. Is a convex surface, the surface of the second transparent substrate on the side where the second transparent electrode is formed is a concave surface, and the surface of the second transparent substrate on which the second transparent electrode is formed The surface on the opposite side is a convex surface, and the first liquid crystal layer has a convex lens shape.
A first liquid crystal lens unit;
The surface of the second transparent substrate on which the third transparent electrode is formed is a convex surface, and the surface of the second transparent substrate opposite to the surface on which the third transparent electrode is formed. Is a concave surface, the surface of the third transparent substrate on the side where the fourth transparent electrode is formed is a convex surface, and the surface of the third transparent substrate on which the fourth transparent electrode is formed The surface on the opposite side is concave, and the second liquid crystal layer has a concave lens shape.
A second liquid crystal lens unit;
Controlling the voltage applied to the first transparent electrode and the second transparent electrode of the first liquid crystal lens unit, controlling the electric field formed in the first liquid crystal layer,
Controlling a voltage applied to the third transparent electrode and the fourth transparent electrode of the second liquid crystal lens unit, and controlling an electric field formed in the second liquid crystal layer;
Voltage control means;
With
The first liquid crystal lens unit and the second liquid crystal lens unit are configured to overlap each other, and a first optical axis of the first liquid crystal lens unit and a second of the second liquid crystal lens unit are configured. The optical axis matches,
A liquid crystal lens characterized by that. A liquid crystal lens according to claim 1 ;
A distance measuring means;
A target focal length setting unit that sets a target focal length of the liquid crystal lens based on a measurement result of the distance measuring means;
Further comprising
The voltage control unit controls an electric field formed in the first liquid crystal layer and the second liquid crystal layer based on the target focal length;
A liquid crystal lens characterized by that. The liquid crystal lens according to claim 2 is used as a spectacle lens.
This is a variable focal length glasses. It further comprises a user information recording means for recording the user's eyesight information,
The target focal length setting unit sets the target focal length based on the visual information of the user in addition to the measurement result of the distance measuring unit;
The focal length variable glasses according to claim 3 .

Images