JP3401760B2 - Optical device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device, and more particularly, to optical characteristics of the optical device, such as a focal length of a lens, a deflection angle of a prism, a divergence angle of a lenticular lens, etc., depending on an applied voltage. The present invention relates to an optical device that can change accurately at high speed and continuously.

[0002]

2. Description of the Related Art Most conventional optical devices are passive optical devices, and the types of active optical devices whose optical properties can be changed by a voltage have been limited. Among them, as an optical device using a variable refractive index material, for example, a liquid crystal lens as shown in FIG. 15 has been proposed.
o. 59850048).

As shown in FIG. 15, the structure of this liquid crystal lens is such that a plano-concave lens 91 formed of polymer or glass, a transparent electrode 93 formed on the surface thereof, and a transparent electrode 93 formed on the transparent electrode 93. Alignment film 9 made of polyimide
5, the liquid crystal layer 92, and the counter substrate 910 facing them.
The transparent electrode 94 is formed on the transparent electrode 94, the alignment film 96 made of polyimide or the like is formed on the transparent electrode 94, and a driving device 915 for driving these. Here, a normal nematic liquid crystal in which the dielectric anisotropy is not reversed due to the difference in frequency is used for the liquid crystal layer 92, and the alignment films (95, 96) have the liquid crystal molecules of the liquid crystal layer 92 substantially parallel to each other. It is in a homogeneous orientation so as to be aligned.

When no voltage is applied between the transparent electrode 93 and the transparent electrode 94 from the driving device 915, the liquid crystal molecules of the liquid crystal layer 92 are made substantially parallel to the counter substrate 910 by the action of the alignment films (95, 96). Orient to line up. In this case, the liquid crystal layer 92 appears to have a larger refractive index than the plano-concave lens 91 for the incident light 99 in the polarization state parallel to the alignment direction, and thus the optical device as a whole functions as a plano-convex lens. It is focused like emitted light 98.

On the other hand, when a suitable voltage is applied between the transparent electrode 93 and the transparent electrode 94 from the driving device 915, the liquid crystal molecules of the liquid crystal layer 92 are acted on by the applied voltage to cause the liquid crystal molecules of the liquid crystal layer 92 to face the opposite substrate 910 and the plano-concave lens 91. Oriented perpendicular to. In this case, to the incident light 99, the liquid crystal layer 92 seems to have a refractive index almost the same as that of the plano-concave lens 91, so that the optical device as a whole exerts only the same action as a simple glass plate, and the emitted light 97. The light is emitted in almost the same direction as the incident light.

As described above, in the liquid crystal lens shown in FIG. 15, the focal length of the plano-convex lens can be continuously changed by the applied voltage.

[0007]

As described above, FIG.
Also in the conventional optical device shown in FIG. 5, it is possible to continuously change the optical characteristics of the optical device, for example, the focal length of the plano-convex lens, by the applied voltage.

However, in the conventional optical device shown in FIG. 15, the alignment of the liquid crystal molecules of the liquid crystal layer 92 when no voltage is applied is performed only by the alignment regulating force of the alignment films (95, 96). In such an optical device, the thickness of the liquid crystal layer 92 is as large as several hundreds of μm or more, and therefore, FIG.
As shown in (3), the recovery time at the time of driving is extremely slow, being several seconds or more, which is a drawback. Moreover, since the recovery time is a state in which no voltage is applied, almost no improvement is seen, and there is currently no measure for shortening the recovery time.

Further, as shown in FIG. 18, the alignment film (9
5, 96), when the liquid crystal molecules of the liquid crystal layer 92 are aligned only by the alignment regulating force of the liquid crystal layer 92, near the transparent electrode 93,
For example, the liquid crystal molecules of the liquid crystal layer 92 are aligned along the curved surface of the plano-concave lens 91. For this reason, the orientation of the liquid crystal molecules is partially tilted, the refractive index felt by the incident light approaches the refractive index of the plano-concave lens 91, for example, and the amount of change in optical properties becomes small, and the optical properties change depending on the position of the lens. It has a drawback that the distribution of the change amount of is generated.

Further, for example, since the transparent electrode 93 is formed on the surface of the plano-concave lens 91 or the like, when a voltage is applied, an electric field is applied near the transparent electrode 93 in a form perpendicular to the surface, and FIG. As shown in, the liquid crystal molecules of the liquid crystal layer 92 are aligned perpendicular to the surface of the transparent electrode 93.
For this reason, the orientation of the liquid crystal molecules is partially tilted, and a region in which the refractive index felt by the incident light is considerably different from the refractive index of the plano-concave lens 91 is formed. Had a drawback that it was partially deflected.

Further, if the plano-concave lens 91 has a more complicated surface shape, particularly if it has a deep groove or a sharp protrusion, it becomes difficult to form the transparent electrode 93 uniformly, and further, the liquid crystal layer 92. However, there is a drawback in that the alignment treatment of the alignment film 95 for aligning the liquid crystal molecules, such as rubbing treatment, becomes difficult.

Further, as can be seen from FIG. 15, since the distance between the transparent electrodes (93, 94) differs depending on the position and the same voltage is applied to the transparent electrodes (93, 94), deterioration of insulation property or short circuit may occur in the narrowed portion. It had the drawback of being prone to occur.

As described above, the conventional active optical device using the variable refractive index material has many problems in practical use such as long recovery time, nonuniformity, manufacturing or active problems. It had drawbacks.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and an object of the present invention is to enable an optical device to be driven at a high speed, have good uniformity, and be easy to manufacture. It is an object of the present invention to provide a technique capable of actively and continuously changing the optical characteristics periodically.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0016]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows.

A layer including a liquid crystal layer, a layer of a transparent material having a surface shape of a desired curved surface in contact with the liquid crystal layer, a first electrode group composed of a plurality of parallel electrodes, and a first electrode group parallel to each other. A plurality of different electrodes, a second electrode group that faces the first electrode group in parallel with the layer including the liquid crystal layer and the transparent material layer, and the first electrode group and the second electrode group. An optical device having a driving device that applies a voltage to each electrode of the electrode group of, wherein voltages different in amplitude are applied from the driving device to each electrode of the first electrode group and the second electrode group, Changing the direction of the electric field direction in a region surrounded by two adjacent electrodes of the first electrode group and two adjacent electrodes of the second electrode group and in a layer containing liquid crystal It is characterized by

Voltages having different phases are applied from the drive unit to the electrodes of the first electrode group and the second electrode group, and the two adjacent electrodes of the first electrode group and the second electrode are applied. It is characterized in that the direction of the electric field direction in the region surrounded by two adjacent electrodes of the electrode group and in the layer containing the liquid crystal is periodically changed.

The center of gravity of a region surrounded by two adjacent electrodes of the first electrode group and two adjacent electrodes of the second electrode group, and adjacent to the first electrode group. The two adjacent electrodes of the first electrode group and the adjacent two electrodes of the second electrode group are proportional to the distances between the two electrodes and the adjacent two electrodes of the second electrode group. It is characterized in that the amplitude of the voltage applied to the electrodes of the book is increased.

A cross section of two adjacent electrodes of the first electrode group and two adjacent electrodes of the second electrode group taken along a plane orthogonal to the plurality of parallel electrodes is substantially the same. The electrodes are arranged in a square position, and the phases of the voltages applied to the two adjacent electrodes of the first electrode group and the two adjacent electrodes of the second electrode group are orthogonal to the plurality of parallel electrodes. It is characterized in that the cross section cut by a plane is shifted 90 degrees clockwise (or counterclockwise).

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In all the drawings for explaining the embodiments, parts having the same function are designated by the same reference numerals, and the repeated description thereof will be omitted.

[Embodiment 1] FIG. 1 is a cross-sectional view of essential parts showing a schematic configuration of an optical device according to Embodiment 1 of the present invention.
The optical device according to the present embodiment includes a substrate (110, 111)
A transparent material layer 11, a liquid crystal layer 12, and a plurality of parallel electrodes sandwiching the transparent material layer 11 and the liquid crystal layer 12 (in FIG. 1, four electrodes (13, 14, 15, 16)). (Only numbered), and a driving device 115 for driving these. Here, the substrate (110, 1
11) is formed of, for example, glass, polymer, insulated metal, or the like, and the transparent material layer 11 is formed of, for example, transparent polymer or glass. Further, for the liquid crystal layer 12, for example, nematic liquid crystal or smectic liquid crystal is used.

A plurality of parallel electrodes, eg electrodes (13,
14, 15, 16) are ITO, tin oxide (SnOx), which is a transparent electrode, and aluminum (A
l) It is formed by an electrode or a combination thereof. Here, each electrode on the substrate 110 side, that is, each electrode including the electrodes (13, 14) shown in FIG. 1 is a first electrode group,
Further, each electrode on the substrate 111 side, that is, each electrode including the electrodes (15, 16) shown in FIG. 1 constitutes a second electrode group.

In the present embodiment, as an example of the active optical device, for example, it is intended to provide a plano-convex lens (focal length is positive) having a variable focal length, and, for example, refraction of the liquid crystal layer 12 is performed. When the refractive index is larger than the refractive index of the transparent material layer 11, the liquid crystal layer 12 having a large refractive index is used.
However, for example, a case of a convex lens shape will be described. In this case, the surface shape of the transparent material layer 11 on the liquid crystal layer 12 side is, for example, a concave Fresnel lens shape as shown in FIG. Of course, for example, when the refractive index of the liquid crystal layer 12 is smaller than that of the transparent material layer 11,
It is clear that the surface shape of the transparent material layer 11 on the liquid crystal layer 12 side may be, for example, a convex Fresnel lens shape as shown in FIG. 10 described later.

In the present embodiment, in order to simplify the explanation, the electrodes (13, 14, 15, 16) are viewed at a substantially square position (however, a cross section taken along a plane orthogonal to a plurality of electrodes parallel to each other). Case). In addition, the liquid crystal layer 1
No. 2 has a positive dielectric anisotropy, and as the refractive index anisotropy, n _o (normal refractive index) is almost equal to the refractive index of the transparent material layer 11, and n _e (abnormal refractive index) A liquid crystal layer 12 is used which is substantially larger than the layer 11 of transparent material.

Therefore, in the present embodiment, the liquid crystal layer 1
When the liquid crystal molecules of No. 2 are aligned perpendicular to the substrate (110, 111), the refractive index of the transparent material layer 11 and the liquid crystal layer 12 become equal, and the incident light 19 is hardly changed and the emitted light is It is emitted as 17. On the other hand, when the liquid crystal molecules of the liquid crystal layer 12 are aligned parallel to the substrate (110, 111), the refractive index of the liquid crystal layer 12 is larger than that of the transparent material layer 11, and the liquid crystal molecules are aligned parallel to the alignment direction of the liquid crystal. The incident light 19 having polarization functions as a convex Fresnel lens, and thus is focused like the emitted light 18, for example. When the liquid crystal molecules of the liquid crystal layer 12 have an inclination between the two, the refractive index of the liquid crystal layer 12 also takes an intermediate value, so that it functions as a lens with a variable focal length. It is almost the same as the example.

2 and 3 are diagrams for explaining the operating principle of the optical device according to the first embodiment. As described above, in the conventional example, the liquid crystal layer (92 shown in FIG. 15) has a large thickness of, for example, several hundreds of μm, so that the speed at which the liquid crystal molecules recover from the state perpendicular to the substrate to the state parallel to the substrate is about several seconds. And because the applied voltage is zero,
I couldn't respond at high speed.

On the other hand, in this embodiment, for example, as shown in FIG. 2, the electrodes (13, 14) are set to the same voltage V11, and the electrodes (15, 16) are set to the same voltage V12.
In addition, from the state where a sufficient voltage difference is applied between the voltage (V11) and the voltage (V12), for example, as shown in FIG. 3, the electrodes (13, 15) are set to the same voltage V13 and the electrode (14 , 16) are the same voltage V14, and the voltage (V
13) and the voltage (V14) to a state in which a sufficient voltage difference is applied, the driving device 115 drives the electrodes (13, 14, 15,
The voltage applied to 16) is changed. As a result, the electric field in the region surrounded by the electrodes (13, 14, 15, 16) and in the region of the liquid crystal layer 12 is changed from the spatially substantially uniform electric field E11 to another spatially uniform uniform direction. It can be changed to the electric field E12.

Therefore, when the liquid crystal molecules in this region have a positive dielectric anisotropy, the liquid crystal molecules have an electric field E.
It changes according to the direction of the electric field from the direction parallel to 11 to the direction parallel to the electric field E12, that is, from the state perpendicular to the substrates (110, 111) to the state parallel thereto. As described above, in this embodiment, since the orientation of the liquid crystal molecules is changed by the orientation change of the electric field, the speed can be increased as compared with the conventional example shown in FIG. 15, and the strength of the electric field can be further increased. It has the advantage that the speed can be increased.

The voltage application method shown in FIGS. 2 and 3 is an example, and the direction of the electric field E is continuously changed by changing the amplitude of the voltage applied to the electrodes (13, 14, 15, 16). Obviously, it can be changed in any direction.
Further, in the present embodiment, unlike the conventional example shown in FIG. 15, the orientation of liquid crystal molecules is determined mainly by the orientation of the electric field rather than the orientation regulating force, which is difficult to measure, so that orientation can be accurately controlled. Has the advantage. Therefore, in the optical device according to the present embodiment, the optical characteristics (for example, the focal length) can be changed accurately at high speed and continuously.

In addition, since the movement of the liquid crystal molecules of the present embodiment mainly depends on the direction of the electric field, it has an advantage that it is less affected by the surface state of the layer in contact therewith as compared with the conventional example shown in FIG. . In addition, in the present embodiment, since the electrode 13 is not provided on the surface of the transparent material layer 11, it is not necessary to form a conductive film in a portion having a complicated shape, which is more difficult than the conventional example shown in FIG. Has the advantage that it becomes easier.
Further, it is easy to make the distance between the electrodes, for example, the electrode 13 and the electrode 15 approximately the same, and the transparent material layer 11 may exist between the electrodes. Differently, it also has the advantage that insulation deterioration and short circuiting are less likely to occur. As described above, in the present embodiment, the driving speed can be increased, the uniformity, the ease of manufacture, and the driving problems can be solved, as compared with the conventional example.
Here, in the present embodiment, if the dielectric constant of the transparent material layer 11 and the dielectric constant of the liquid crystal layer 12 are substantially the same, it is clear that the direction of the electric field can be easily controlled and the uniformity can be easily obtained. Is.

In the present embodiment, the liquid crystal layer 12 is
Although the case where the liquid crystal layer 12 has a positive dielectric anisotropy has been described, it is clear that the same effect as described above can be obtained even when the liquid crystal layer 12 has a negative dielectric anisotropy.
However, when the liquid crystal layer 12 has a negative dielectric anisotropy, the liquid crystal molecules tend to be perpendicular to the direction of the electric field, so that the degree of freedom in the perpendicular plane is generated and some May cause instability. Of course, since the electrodes are usually the controls, their freedom is considered to be limited.

Further, in the present embodiment, in order to simplify the explanation, the case where the electrodes (13, 14, 15, 16) are arranged in a substantially square position has been described, but as will be described later, the electrodes (13 , 14, 15, 16), even if the arrangement shape is different from the substantially square position, the electrode (1
3, 14, 15, 16) and by adjusting the amplitude of the voltage applied to the electrodes (13, 14, 15, 16) so as to give a substantially uniform electric field in the region of the liquid crystal layer 12. The good is clear.

In this embodiment, as described above, the refractive index of the transparent material layer 11 and the refractive index variable material, for example, the liquid crystal layer 12 have the same extraordinary refractive index or normal refractive index. It may be set to a value close to it. However, it is not always necessary to set these refractive indices to the same value or a close value, and similar effects can be obtained as follows. That is, for example, considering the case of a fixed focus lens as the layer 11 of transparent material, setting the refractive index to the same value or a value close thereto means setting the focal length in that case to near infinity. Equivalent to. For example, if it is difficult for the material to make the refractive index the same value or a value close to it, or if such a material has another physical property value (for example,
Even if it is disadvantageous due to the relationship of dielectric anisotropy, refractive index anisotropy, temperature characteristics, miscibility with solvent, toxicity, etc., simply attach another fixed focus lens before and after this variable focus lens. This can be solved by simply disposing it and correcting the focal length.

Further, in the present embodiment, the case where the refractive index of the liquid crystal layer 12 is substantially larger than the refractive index of the transparent material layer 11 has been described, but the present invention is not limited to this, and the liquid crystal layer 12 is not limited thereto. Even when the refractive index is substantially smaller than the refractive index of the transparent material layer 11, or even when the value of the refractive index of the transparent material layer 11 is within the variable range of the refractive index of the liquid crystal layer 13, It is clear that the same effect can be obtained.

Further, in this embodiment, the transparent material layer 1 is used.
Although the case where the Fresnel lens shape is used as the surface shape on the liquid crystal layer 12 side of No. 1 is not limited to this, the surface shape on the liquid crystal layer 12 side of the transparent material layer 11 is a convex lens shape, It is obvious that the same effect can be obtained even when the concave lens shape, the prism array shape, the lenticular lens shape, the lens array shape, the diffraction grating shape, or the curved surface shape in which these are combined is included.

Further, in the present embodiment, the refractive index of the liquid crystal layer 12 and the refractive index of the transparent material layer 11 are such that the liquid crystal molecules stand perpendicular to the electrodes (13, 14, 15, 16). In the above description, the case where the two are substantially equal is described, but the present invention is not limited to this, and liquid crystal molecules are used as electrodes (13, 1).
4, 15 and 16) when they are parallel to each other or when the liquid crystal molecules are in the electrode (13, 1).
It is obvious that the same effect as that of the present embodiment can be obtained even when both are substantially equal when a certain angle is formed with respect to (4, 15, 16).

[Embodiment 2] FIG. 4 is a cross-sectional view of essential parts showing a schematic structure of an optical device according to Embodiment 2 of the present invention.
The optical device of the present embodiment is similar to that of the first embodiment.
The substrate (210, 211), the transparent material layer 21, the liquid crystal layer 22, and a plurality of parallel electrodes (in FIG. 4, four electrodes (23, 23) sandwiching the transparent material layer 21 and the liquid crystal layer 22). Two
Only numbers 4, 25, 26) are numbered. ) And a driving device 215 for driving them.
Here, each electrode on the substrate 210 side, that is, each electrode including the electrodes (23, 24) shown in FIG. 4 constitutes the first electrode group,
Each electrode on the substrate 211 side, that is, the electrodes (25,
Each electrode including 26) constitutes a second electrode group.

Further, in the present embodiment, as in the first embodiment, as an example of an active optical device, for example, a plano-convex lens (focal length is positive) having a variable focal length is provided, and For example, the case where the refractive index of the liquid crystal layer 22 is substantially larger than the refractive index of the transparent material layer 21, and the liquid crystal layer 22 having a large refractive index has, for example, a convex lens shape will be described.

Further, in the present embodiment, in order to simplify the explanation, the electrodes (23,
24, 25, 26) are arranged in a substantially square position (however, when viewed in a cross section taken along a plane orthogonal to a plurality of parallel electrodes). The liquid crystal layer 22 has positive dielectric anisotropy, and further, the refractive index anisotropy, substantially equal to n _o (ordinary index) refractive index of the layer 21 of transparent material,
A liquid crystal layer having a larger n _e (abnormal refractive index) than the transparent material layer 21 is used.

Therefore, in this embodiment, as in the case of the first embodiment, the liquid crystal molecules of the liquid crystal layer 22 are formed on the substrate (210,
211), the refractive index of the transparent material layer 21 becomes equal to that of the liquid crystal layer 22, and the incident light 29
Is emitted as outgoing light 27 with almost no change.
On the other hand, the liquid crystal molecules of the liquid crystal layer 22 are the substrates (210, 211).
When the liquid crystal layer 22 is oriented parallel to the liquid crystal layer 22, the refractive index of the liquid crystal layer 22 becomes larger than that of the transparent material layer 21, and the liquid crystal layer 22 functions as a convex Fresnel lens for incident light 29 having polarized light parallel to the alignment direction of the liquid crystal molecules. Therefore, for example, the light is focused like the emitted light 28. When the liquid crystal molecules of the liquid crystal layer 22 have an intermediate inclination between the two, the refractive index of the liquid crystal layer 22 also takes an intermediate value, so that the lens functions as a lens whose focal length changes.

In the present embodiment, as shown in FIG. 4, each electrode of the first electrode group and the second electrode group of the optical device is
When the voltages have different phases, for example, four electrodes, the phases of the voltages are, for example, clockwise or counterclockwise (however, when viewed in a cross section taken along a plane orthogonal to a plurality of parallel electrodes). ,) Deviated by 90 degrees, for example,
Apply a sinusoidal voltage. This allows the electrodes (23, 2
4, 25, 26) and the direction of the substantially uniform electric field E in the region of the liquid crystal layer 22 is clockwise or counterclockwise (however, in a plane orthogonal to a plurality of parallel electrodes). It can be changed continuously and periodically when viewed in a cut section). Therefore, when the direction of the liquid crystal molecules in this region has a positive dielectric anisotropy,
To change continuously in a clockwise direction or in a counterclockwise direction (when viewed in a cross section taken along a plane orthogonal to a plurality of parallel electrodes) parallel to the direction of the electric field E and in a time-periodic manner. You can

As described above, in the present embodiment, the orientation of the liquid crystal molecules can be accurately and periodically changed at high speed and continuously by changing the orientation of the electric field. Of course, the speed can be increased by further increasing the strength of the electric field, as in the first embodiment. Therefore, in this embodiment, the optical characteristics of the optical device, that is,
It is possible to change the focal length and the like at high speed, continuously, and accurately and periodically.

In the present embodiment, the case where the liquid crystal layer 22 has a positive dielectric anisotropy has been described. However, even when the liquid crystal layer 22 has a negative dielectric anisotropy, It is clear that the same effect as can be obtained. However,
When the liquid crystal layer 22 has a negative dielectric anisotropy, the liquid crystal molecules tend to be perpendicular to the direction of the electric field, so that the degree of freedom in the perpendicular plane is generated and some instability factors are caused. There is a possibility that Of course, since the electrodes are usually the controls, their freedom is considered to be limited.

Further, in the present embodiment, in order to simplify the description, the case where the electrodes (23, 24, 25, 26) are arranged in a substantially square position has been described, but as will be described later, the electrodes (23 , 24, 25, 26) has an arrangement shape different from the substantially square position, the electrodes (2
3, 24, 25, 26) and by adjusting the amplitude of the voltage applied to the electrodes (23, 24, 25, 26) so as to provide a substantially uniform electric field in the region of the liquid crystal layer 22. The good is clear.

In the present embodiment, the case where the voltage applied to each electrode is a sine wave has been described, but it goes without saying that the waveform of this voltage does not necessarily have to be a sine wave, and the region surrounded by the electrodes is not necessarily required. It is obvious that any waveform can be used as long as it changes so that the electric field becomes almost uniform.

In this embodiment, as described above, the refractive index of the transparent material layer 21 and the refractive index variable material, for example, the liquid crystal layer 22 have the same extraordinary refractive index or normal refractive index. It may be set to a value close to it. However, it is not always necessary to set these refractive indices to the same value or a close value, and similar effects can be obtained as follows. That is, for example, considering a case of a fixed focus lens as the transparent material layer 21, setting the refractive index to the same value or a close value means setting the focal length in that case to near infinity. Equivalent to. For example, if it is difficult for the material to make the refractive index the same value or a value close to it, or if such a material has another physical property value (for example,
Even if it is disadvantageous due to the relationship of dielectric anisotropy, refractive index anisotropy, temperature characteristics, miscibility with solvent, toxicity, etc., simply attach another fixed focus lens before and after this variable focus lens. This can be solved by simply disposing it and correcting the focal length.

In the above description, the case where the present invention is applied to a region surrounded by four electrodes (23, 24, 25, 26) has been described, but other four electrodes adjacent to this region are used. It is clear that the same effect can be expected by applying the present invention to the enclosed area. However, in the adjacent area, any of the four electrodes (23, 24, 25, 26) in the area becomes a common electrode in the adjacent area (for example, in the case of the adjacent area on the left side in FIG. (23, 25) is a common electrode).

Therefore, in the adjacent regions, the direction in which the liquid crystal molecules change direction is reversed (for example,
If one is clockwise, the adjacent region is counterclockwise), and it is possible to assign voltages to the electrodes in each region without contradiction. In this case, since the liquid crystal molecules move in opposite directions in the adjacent regions, there is a possibility that a domain will be generated at this boundary. However, since the electrode spacing can be made sufficiently large, even if domains occur spatially periodically at this site,
This is unlikely to have any adverse effects such as confusion.

[Third Embodiment] FIG. 5 is a cross-sectional view of essential parts showing a schematic structure of an optical device according to a third embodiment of the present invention.
The optical device of the present embodiment is similar to the first and second embodiments, in that the substrate (710, 711), the transparent material layer 71,
The liquid crystal layer 72 and a plurality of parallel electrodes sandwiching the transparent material layer 71 and the liquid crystal layer 72 (in FIG. 5, four electrodes (7
3, 74, 75, 76) are numbered only),
And a driving device 715 for driving these. Here, each electrode on the substrate 710 side, that is, each electrode including the electrodes (73, 74) shown in FIG. 5 is the first electrode group, and each electrode on the substrate 711 side, that is, the electrode shown in FIG. (7
5, 76) each of which constitutes a second electrode group.

Further, in the present embodiment, the first embodiment will be described.
Similar to the example 2, as an example of an active optical device, for example, a plano-convex lens (focal length is positive) with a variable focal length is provided, and, for example, the refractive index of the liquid crystal layer 72 is made of a transparent material. A case where the liquid crystal layer 72 having a larger refractive index than the layer 71 and having a large refractive index has, for example, a convex lens shape will be described.

Further, in the present embodiment, in order to simplify the explanation, as in the first and second embodiments, the electrode (7
3, 74, 75, 76) are arranged in a substantially square position (however, when viewed in a cross section taken along a plane orthogonal to a plurality of parallel electrodes). The liquid crystal layer 72 has a positive dielectric anisotropy, and further has a refractive index anisotropy of n.
_o substantially equal to the (ordinary index) refractive index of the layer 71 of transparent material, n _e (extraordinary refractive index) is used generally larger crystal layer than the layer 71 of transparent material.

Therefore, in this embodiment, the liquid crystal molecules of the liquid crystal layer 72 are the same as those in the first and second embodiments.
10, 711), the transparent material layer 71 and the liquid crystal layer 72 have the same refractive index, and the incident light 79 is emitted as the emitted light 77 with almost no change. On the other hand, the liquid crystal molecules of the liquid crystal layer 72 are
11), the liquid crystal layer 72 has a higher refractive index than the transparent material layer 71, and a convex Fresnel lens for incident light 79 having a polarization parallel to the alignment direction of the liquid crystal molecules. Therefore, the light is focused like the emitted light 78, for example. When the liquid crystal molecules of the liquid crystal layer 72 have an intermediate inclination between the two, the refractive index of the liquid crystal layer 72 also takes an intermediate value, so that it functions as a lens with a variable focal length.

As described in the second embodiment, when the voltage applied to the electrodes is continuous, it is necessary to reverse the movement of the liquid crystal molecules in the adjacent regions, which may cause a domain. is there. Although it is considered that the adverse effect of this is small, when the control of the movement of the liquid crystal molecules is not so precise, this factor can be removed by the voltage application method as described below.

First, as described in the above embodiment,
Even in the region adjacent to the region surrounded by the electrodes (73, 74, 75, 76), the voltage arrangement for orienting the liquid crystal molecules in the same direction is used when the liquid crystal molecules are perpendicular to the substrate. , A voltage of the same potential may be applied to each electrode of the first electrode group, and a voltage of the same potential may be applied to each electrode of the second electrode group, and the liquid crystal molecules may move in one direction horizontal to the substrate. In the case of sleeping, for example, when the spontaneous polarization of the liquid crystal molecules is sufficiently small, the liquid crystal molecules are aligned only in the direction of the electric field. Therefore, the electrodes in the lateral direction of the first electrode group and the second electrode group are aligned. , A voltage which is repeated large, small, large, small, ...

Therefore, the voltages applied to the electrodes may be set to these voltages, and the movement of the liquid crystal molecules in the middle may be left in balance with the viscosity of the liquid crystal layer. That is, for example, as shown in FIG. 5, the voltage of each electrode of the optical device includes discontinuity with different phases or abrupt changes, for example, when there are four electrodes, the phase is, for example, 90%. Shifted by degrees, for example,
A rectangular wave voltage is applied. This allows these electrodes (7
3, 74, 75, 76) and its adjacent area, the electric field is an electric field perpendicular to the substrate (710, 711) and an electric field lying in one direction horizontal to the substrate (710, 711). Are applied periodically (when viewed in a cross section taken along a plane orthogonal to a plurality of parallel electrodes).

Therefore, when the liquid crystal layer 72 in this region has a positive dielectric anisotropy, the liquid crystal molecules try to move parallel to the direction of the electric field E. However, since the liquid crystal layer 72 is viscous, the orientation of the liquid crystal molecules does not change discontinuously but changes continuously under the balance between the change in the electric field and the viscosity. Moreover, since the liquid crystal layer 7 has crystallinity, the same movement is attempted in each region, and as a result, it is continuous,
Moreover, almost uniform movements can be realized in each region.

As described above, in the present embodiment, it is possible to change the orientation of liquid crystal molecules at high speed and continuously, and periodically while suppressing the generation of domains.

Of course, the speed can be increased by further increasing the strength of the electric field, as in the first and second embodiments.

Although the case where the liquid crystal layer 72 has a positive dielectric anisotropy has been described in the present embodiment, even when the liquid crystal layer 72 has a negative dielectric anisotropy, It is clear that the same effect as can be obtained. However,
When the liquid crystal layer 72 has a negative dielectric anisotropy, the liquid crystal molecules tend to be perpendicular to the direction of the electric field, so that the degree of freedom in the perpendicular plane is generated and some instability factors are caused. There is a possibility that Of course, since the electrodes are usually the controls, their freedom is considered to be limited.

Further, in the present embodiment, in order to simplify the description, the case where the electrodes (73, 74, 75, 76) are arranged in a substantially square position has been described, but as will be described later, the electrodes (73 , 74, 75, 76) has a shape different from the substantially square position, the electrodes (7
3, 74, 75, 76) and by adjusting the amplitude of the voltage applied to the electrodes (73, 74, 75, 76) so as to give a substantially uniform electric field in the region of the liquid crystal layer 72. The good is clear.

In this embodiment, as described above, the refractive index of the transparent material layer 71 is the same as the refractive index variable material, for example, the liquid crystal layer 72, which has either the extraordinary refractive index or the normal refractive index. It may be set to a value close to it. However, it is not always necessary to set these refractive indices to the same value or a close value, and similar effects can be obtained as follows. That is, for example, considering the case of a fixed focus lens as the transparent material layer 71, setting the refractive index to the same value or a close value means setting the focal length in that case to near infinity. Equivalent to. For example, if it is difficult for the material to make the refractive index the same value or a value close to it, or if such a material has another physical property value (for example,
Even if it is disadvantageous due to the relationship of dielectric anisotropy, refractive index anisotropy, temperature characteristics, miscibility with solvent, toxicity, etc., simply attach another fixed focus lens before and after this variable focus lens. This can be solved by simply disposing it and correcting the focal length.

[Fourth Embodiment] FIG. 6 is a cross-sectional view of an essential part showing a schematic structure of an optical device according to a fourth embodiment of the present invention.
The optical device of the present embodiment is similar to the first and second embodiments in that the substrate (810, 811), the transparent material layer 81,
The liquid crystal layer 82 and a plurality of parallel electrodes sandwiching the transparent material layer 81 and the liquid crystal layer 82 (four electrodes (8
3, 84, 85, 86) are numbered only),
And a drive device 815 for driving these. Here, each electrode on the substrate 810 side, that is, each electrode including the electrodes (83, 84) shown in FIG. 6 is the first electrode group, and each electrode on the substrate 811 side, that is, the electrode shown in FIG. (8
5,86) each electrode constitutes a second electrode group.

Also in the present embodiment, as in the first and second embodiments, as an example of the active optical device, for example, a plano-convex lens with a variable focal length (plus focal length) is used.
And the case where the refractive index of the liquid crystal layer 82 is generally larger than the refractive index of the transparent material layer 81, and the liquid crystal layer 82 having a large refractive index is formed into a convex lens shape, for example. is doing.

Further, in the present embodiment, in order to simplify the explanation, the electrode (8
3, 84, 85, 86) are arranged in a substantially square position (however, when viewed in a cross section taken along a plane orthogonal to mutually parallel electrodes). The liquid crystal layer 82 has positive dielectric anisotropy, and further, the refractive index anisotropy, substantially equal to n _o (ordinary index) refractive index of the layer 81 of transparent material, n
_The case where the liquid crystal layer has a larger _e (abnormal refractive index) than the transparent material layer 81 will be described.

Therefore, in the present embodiment, when the liquid crystal molecules of the liquid crystal layer 82 are aligned perpendicularly to the substrates (810, 811), the transparent material layer 81 and the liquid crystal layer 82 are formed.
Have the same refractive index, and the incident light 89 is emitted as outgoing light 87 with almost no change. On the other hand, when the liquid crystal molecules of the liquid crystal layer 82 are aligned parallel to the substrate (810, 811), the refractive index of the liquid crystal layer 82 is higher than that of the transparent material layer 81, and the liquid crystal molecules are parallel to the alignment direction of the liquid crystal molecules. Since it functions as a convex Fresnel lens with respect to the incident light 89 having various polarizations, it is focused like the outgoing light 88, for example. When the liquid crystal molecules of the liquid crystal layer 82 have an inclination between the two, the refractive index of the liquid crystal layer 82 also takes an intermediate value, so that the lens functions as a lens whose focal length changes.

Further, as shown in FIG. 6, in the present embodiment, since the electrodes are sparse, unlike the first and second embodiments, the distance to the next electrode is sufficiently large and the voltage is The need to consider adjacent regions for placement is significantly reduced. Further, the electric field is weak in the region where the electrodes are sparse, and the crystallinity of the liquid crystal layer 82 causes the liquid crystal molecules to move similarly to the surroundings. Therefore, for example, the electrodes (83, 84, 85, 8).
When the liquid crystal molecules in the area surrounded by 6) are moved by an electric field,
The liquid crystal molecules in the region where the electrodes are sparse also move in the same manner.
Therefore, uniform movement of the liquid crystal molecules can be realized as a whole. However, depending on the length of the area where the electrodes are sparse, the time until uniform movement of the liquid crystal molecules becomes longer, so this length should be adjusted according to the speed of change in optical characteristics required for the optical device. You have to choose.

As described above, in the present embodiment, the crystallinity of the liquid crystal layer 82 is greatly utilized when the movement of the liquid crystal molecules is not required to be controlled so precisely, so that the direction of the liquid crystal molecules can be changed to the speed of light. In addition, it is possible to change it continuously and periodically while suppressing the generation of domains. Of course, the speed can be increased by further increasing the strength of the electric field, as in the first and second embodiments.

Although the case where the liquid crystal layer 82 has a positive dielectric constant anisotropy has been described in the present embodiment, even when the liquid crystal layer 82 has a negative dielectric constant anisotropy, It is clear that the same effect as can be obtained. However,
When the liquid crystal layer 82 has a negative dielectric anisotropy, the liquid crystal molecules tend to be perpendicular to the direction of the electric field, so that the degree of freedom in the vertical plane is generated and some instability factor is generated. There is a possibility that Of course, since the electrodes are usually the controls, their freedom is considered to be limited.

Further, in the present embodiment, in order to simplify the description, the electrodes (83, 84, 85, 86) are viewed in a substantially square position (however, the electrodes (83, 84, 85, 86) are viewed in a cross section taken along a plane orthogonal to the mutually parallel electrodes). However, the arrangement of the electrodes (83, 84, 85, 86) is as follows.
Even if the arrangement shape is different from the substantially square position, the electrode (8
3, 84, 85, 86) and by adjusting the amplitude of the voltage applied to the electrodes (83, 84, 85, 86) so as to give a substantially uniform electric field in the region of the liquid crystal layer 82. The good is clear.

In this embodiment, as described above, the refractive index of the transparent material layer 81 is the same as the refractive index variable material, for example, the liquid crystal layer 82, which has either the extraordinary refractive index or the normal refractive index. It may be set to a value close to it. However, it is not always necessary to set these refractive indices to the same value or a close value, and similar effects can be obtained as follows. That is, for example, considering the case of a fixed focus lens as the transparent material layer 81, setting the refractive index to the same value or a value close to that in that case means setting the focal length to near infinity. Equivalent to. For example, if it is difficult for the material to make the refractive index the same value or a value close to it, or if such a material has another physical property value (for example,
Even if it is disadvantageous due to the relationship of dielectric anisotropy, refractive index anisotropy, temperature characteristics, miscibility with solvent, toxicity, etc., simply attach another fixed focus lens before and after this variable focus lens. This can be solved by simply disposing it and correcting the focal length.

[Fifth Embodiment] FIG. 7 is a diagram showing a schematic structure of an optical device according to a fifth embodiment of the present invention. FIG. 7 (a) is a sectional view of the main part, and FIG. 7 (b). Is the same figure (a)
Each electrode (lower electrode) (35, 3) of the second electrode group shown in
It is a figure which shows the relationship between 6) and the film | membrane 310.

A plurality of electrodes, such as the electrodes (13, 14, 15, 16) in the first embodiment, or the electrodes (23, 24, 25, 26) in the second embodiment, are used for these electrodes. It is important to generate an electric field that is as uniform as possible within the enclosed area. In the present embodiment, a film 310 having a higher electric resistance than the resistance values of the electrodes (33, 34) and a uniform electric resistance value is disposed between these electrodes, for example, the electrodes 33 and 34, In addition, these electrodes (33, 34) are electrically connected to the film 310.

With such a structure, the film 31
The potential near 0 changes almost linearly between the potentials of the electrodes 33 and 34. Therefore, the present embodiment has an advantage that the electric field in the region surrounded by the electrodes (33, 34, 35, 36) can be made more uniform. However, since an electric current is passed through the film 310,
The power consumption of the optical device may increase. As a means for suppressing this, for example, it is effective to arrange the films 310 in a line / space pattern as shown in FIG.

[Sixth Embodiment] FIG. 8 is a diagram for explaining the arrangement of electrodes in an optical device according to a sixth embodiment of the present invention.

A plurality of electrodes, for example, the electrodes (13, 14, 15, 16) in the first embodiment or the electrodes (23, 24, 25, 26) in the second embodiment.
, Etc., in the area surrounded by these electrodes,
It is important to generate an electric field that is as uniform as possible. In the first and second embodiments, the arrangement of the electrodes is shown, for example, in a substantially square position (however, when viewed in a cross section taken along a plane orthogonal to the electrodes parallel to each other). It is self-evident that the arrangement is acceptable.

Since the pointer in this case has a uniform electric field inside, as the electrodes move away from the center of gravity of these electrodes, as shown in FIG. 8, an equipotential surface corresponding to the distance is sandwiched between them. As can be seen, it is to apply a voltage proportional to the distance of the electrode from the position of the center of gravity. However, it is necessary to compensate for the secondary disturbance of the electric field by inserting the electrode.

[Seventh Embodiment] FIG. 9 is a cross-sectional view of an essential part showing a schematic structure of an optical device according to a seventh embodiment of the present invention.
Like the first and second embodiments, the optical device of the present embodiment has the substrate (510, 511) and the transparent substance layer 501.
A liquid crystal layer 52, a transparent material layer 501, and a plurality of parallel electrodes sandwiching the liquid crystal layer 52 (in FIG. 6, four electrodes (53,
54, 55, 56) only) and a driving device 515 for driving these.
Here, each electrode on the substrate 510 side, that is, each electrode including the electrodes (53, 54) shown in FIG. 9 constitutes the first electrode group,
Each electrode on the substrate 511 side, that is, the electrodes (55,
Each electrode including 56) constitutes a second electrode group.

[0080] In this embodiment, as the liquid crystal layer 52, n _o approximately equal to (ordinary index) refractive index of the layer 501 of transparent material, n _e layer (extraordinary index of refraction) of a transparent material 50
A liquid crystal layer larger than 1 is used.

In this embodiment, the surface shape of the transparent substance layer 501 on the liquid crystal layer 52 side is a concave lens shape. When the voltages shown in the first to sixth embodiments are applied to a plurality of electrodes, for example, four electrodes (53, 54, 55, 56), a region surrounded by the four electrodes (53, 54, 55, 56) An almost uniform electric field can be generated therein, and the direction of this electric field can be changed accurately at high speed and continuously. Therefore, the orientation of the liquid crystal molecules of the liquid crystal layer 52 can be continuously changed at high speed and accurately,
The difference in refractive index between the transparent substance layer 501 and the liquid crystal layer 52 changes accurately at high speed and continuously. Therefore, the optical device of the present embodiment functions as a convex lens that can change accurately at high speed and continuously based on this difference in refractive index.

[Embodiment 8] FIG. 10 is a cross-sectional view of essential parts showing a schematic structure of an optical device according to Embodiment 8 of the present invention. The optical device of the present embodiment is different from that of the seventh embodiment in that the surface shape of the transparent material layer 502 on the liquid crystal layer 52 side is a convex Fresnel lens shape. The same as Form 7.

The voltages shown in the first to sixth embodiments are applied to a plurality of electrodes, for example, four electrodes (53, 54, 55, 56).
Applied to four electrodes (53, 54, 55, 56)
A uniform electric field can be generated in the area surrounded by
The direction of this electric field can be changed accurately at high speed and continuously. Therefore, the orientation of the liquid crystal molecules of the liquid crystal layer 52 can be changed accurately at high speed and continuously, and the difference in the refractive index between the transparent material layer 502 and the liquid crystal layer 52 can be changed at high speed and continuously. Change exactly. Therefore, the optical device of the present embodiment functions as a concave Fresnel lens capable of changing the focal length accurately at high speed and continuously based on this difference in refractive index.

[Ninth Embodiment] FIG. 11 is a cross-sectional view of an essential part showing a schematic structure of an optical device according to a ninth embodiment of the present invention. The optical device of this embodiment is different from that of the seventh embodiment in that the surface shape of the transparent material layer 503 on the liquid crystal layer 52 side is a prism array shape, but the other configurations are the same as those of the seventh embodiment. It is the same as the form 7.

The voltages shown in the first to sixth embodiments are applied to a plurality of electrodes, for example, four electrodes (53, 54, 55, 56).
Applied to four electrodes (53, 54, 55, 56)
A uniform electric field can be generated in the area surrounded by
The direction of this electric field can be changed accurately at high speed and continuously. Therefore, the orientation of the liquid crystal molecules of the liquid crystal layer 52 can be changed accurately at high speed and continuously, and the difference in the refractive index between the transparent material layer 503 and the liquid crystal layer 52 can be changed at high speed and continuously. Change exactly. Therefore, the optical device of the present embodiment functions as an optical deflecting device capable of changing the deflection angle accurately at high speed and continuously based on this difference in refractive index.

[Embodiment 10] FIG. 12 is a cross-sectional view of essential parts showing a schematic structure of an optical device according to Embodiment 10 of the present invention. The optical device of the present embodiment has a transparent material layer 504.
The third embodiment is different from the seventh embodiment in that the surface shape on the liquid crystal layer 52 side is a concave lenticular lens shape, but the other configurations are the same as the seventh embodiment.

The voltages shown in the first to sixth embodiments are applied to a plurality of electrodes, for example, four electrodes (53, 54, 55, 56).
Applied to four electrodes (53, 54, 55, 56)
A uniform electric field can be generated in the area surrounded by
The direction of this electric field can be changed accurately at high speed and continuously. Therefore, the orientation of the liquid crystal molecules of the liquid crystal layer 52 can be changed accurately at high speed and continuously, and the difference in the refractive index between the transparent material layer 504 and the liquid crystal layer 52 can be changed at high speed and continuously. Change exactly. Therefore, the optical device of the present embodiment functions as a lenticular lens capable of accurately changing the focal length and the divergence angle at high speed and continuously based on the difference in the refractive index.

[Embodiment 11] FIG. 13 is a cross-sectional view of an essential part showing a schematic structure of an optical device according to Embodiment 11 of the present invention. The optical device according to the present embodiment has a transparent material layer 505.
In that the surface shape of the liquid crystal layer 52 side of is a diffraction grating shape,
Although different from the seventh embodiment, the other configurations are the same as those of the seventh embodiment.

The voltages shown in the first to sixth embodiments are applied to a plurality of electrodes, for example, four electrodes (53, 54, 55, 56).
Applied to four electrodes (53, 54, 55, 56)
A uniform electric field can be generated in the area surrounded by
The direction of this electric field can be changed accurately at high speed and continuously. Therefore, the orientation of the liquid crystal molecules of the liquid crystal layer 52 can be changed continuously at high speed and accurately, and the difference in the refractive index between the transparent material layer 505 and the liquid crystal layer 52 can be changed at high speed and continuously. Change exactly. Therefore, the optical device of the present embodiment functions as a diffractive optical device, for example, a light deflecting device, which can change the diffraction efficiency accurately at high speed and continuously based on the difference in the refractive index.

[Embodiment 12] FIG. 14 is a cross-sectional view of essential parts showing a schematic structure of an optical device according to Embodiment 12 of the present invention. In the optical device of the present embodiment, the alignment film 60 made of, for example, polyimide, PVA, PVB, or oblique vapor deposition SiO is formed on the surface of the electrodes on the liquid crystal layer 62 side, for example, the electrodes (65, 66). The liquid crystal layer 62 is different from the first embodiment in that the liquid crystal layer 62 includes the alignment film 60, and the other configurations are the same as those in the first embodiment.

By subjecting the alignment film 60 to rubbing treatment, for example, the liquid crystal molecules of the liquid crystal layer 62 thereon can be aligned in a fixed direction. When the liquid crystal molecules of the liquid crystal layer 62 are tilted in a direction parallel to the alignment film 60 by providing the alignment film 60 and performing rubbing treatment, the liquid crystal molecules of the liquid crystal layer 62 have a uniform alignment state in a wide domain region. You can As a result, it is possible to suppress the adverse effects such as the distortion of the electric field or the disorder of the orientation of the liquid crystal molecules due to the disorder, and to prevent the scattering and the white turbidity caused by the orientation of the liquid crystal molecules of the liquid crystal layer 62 in various directions. It will be possible.

As described above, the invention made by the present inventor is
Although the specific description has been given based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the scope of the invention.

[0093]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

According to the present invention, the first electrode group and the second electrode group are made to face each other with the layer of the transparent material and the layer containing the liquid crystal sandwiched therebetween, and adjacent to the first electrode group. Two electrodes and a second
Within a region surrounded by two adjacent electrodes of the electrode group of
Moreover, since the direction of the electric field direction in the layer containing the liquid crystal is changed to change the optical characteristics of the optical device, the optical characteristics of the optical device are actively and accurately changed at high speed and continuously. It becomes possible.

[Brief description of drawings]

FIG. 1 is a main-portion cross-sectional view showing a schematic configuration of an optical device according to a first embodiment of the present invention.

FIG. 2 is a diagram for explaining the operation principle of the optical device according to the first embodiment.

FIG. 3 is a diagram for explaining the operation principle of the optical device according to the first embodiment.

FIG. 4 is a main-portion cross-sectional view showing a schematic configuration of an optical device according to a second embodiment of the present invention.

FIG. 5 is a main-portion cross-sectional view showing a schematic configuration of an optical device according to a third embodiment of the present invention.

FIG. 6 is a main-portion cross-sectional view showing a schematic configuration of an optical device according to a fourth embodiment of the present invention.

7A and 7B are diagrams showing a schematic configuration of an optical device according to a fifth embodiment of the present invention, wherein FIG. 7A is a sectional view of a main part thereof, and FIG. 7B is shown in FIG. It is a figure which shows the relationship between the electrode of a 2nd electrode group, and a film | membrane.

FIG. 8 is a diagram for explaining the arrangement of electrodes in the optical device according to the sixth embodiment of the present invention.

FIG. 9 is a main-portion cross-sectional view showing a schematic configuration of an optical device according to a seventh embodiment of the present invention.

FIG. 10 is a main-portion cross-sectional view showing a schematic configuration of an optical device according to an eighth embodiment of the present invention.

FIG. 11 is a main-portion cross-sectional view showing a schematic configuration of an optical device according to a ninth embodiment of the present invention.

FIG. 12 is a main-portion cross-sectional view showing a schematic configuration of an optical device according to a tenth embodiment of the present invention.

FIG. 13 is a main-portion cross-sectional view showing a schematic configuration of an optical device according to an eleventh embodiment of the present invention.

FIG. 14 is a main-portion cross-sectional view showing a schematic configuration of an optical device according to a twelfth embodiment of the present invention.

FIG. 15 is a cross-sectional view of essential parts showing a schematic configuration of a conventional liquid crystal lens.

16 is a graph showing the relationship between the applied voltage and the focal length of the liquid crystal lens shown in FIG.

17 is a graph showing a recovery time when the liquid crystal lens shown in FIG. 15 is driven.

18 is a diagram for explaining the alignment state of the liquid crystal molecules of the liquid crystal layer 92 on the surface of the plano-concave lens 91 in the liquid crystal lens shown in FIG.

19 is a diagram for explaining the alignment state of the liquid crystal molecules in the liquid crystal layer 92 when a voltage is applied in the liquid crystal lens shown in FIG.

[Explanation of symbols]

11, 21, 61, 71, 81, 501, 502, 50
3,504,505 ... Layers of transparent material, 12,22,5
2, 62, 72, 82, 92 ... Liquid crystal layer, 13 to 16, 2
3 to 26, 33 to 36, 43 to 46, 53 to 56, 63
~ 66, 73 to 76, 83 to 86 ... Electrodes, 19, 29,
39, 59, 69, 79, 89, 99 ... Incident light, 17,
18, 27, 28, 37, 38, 57, 58, 67, 6
8, 77, 78, 87, 88, 97, 98 ... Emitted light, 9
1 ... Plano-concave lens, 93, 94 ... Transparent electrode, 60, 95,
96 ... Alignment film, 110, 111, 210, 211, 51
0,511,610,611,710,711,81
0, 811, ... Substrate, 115, 215, 515, 615,
715, 815, 915 ... Driving device, 310 ... Membrane, 91
0 ... Counter substrate.

─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-2-74925 (JP, A) JP-A-7-128631 (JP, A) JP-A-5-34656 (JP, A) JP-A-2- 113224 (JP, A) JP 9-243960 (JP, A) JP 9-258271 (JP, A) JP 10-26705 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G02F 1/1343 G02F 1/13 505 G02F 1/133 545 G09G 3/36

Claims (8)

(57) [Claims] 1. A layer including a liquid crystal layer, a layer of a transparent material having a surface shape of a desired curved surface in contact with the liquid crystal layer, and a first electrode group composed of a plurality of electrodes parallel to each other. A second electrode group composed of a plurality of electrodes parallel to each other, facing the first electrode group in parallel with the layer including the liquid crystal layer and the transparent material layer, and the first electrode group and An optical device having a driving device that applies a voltage to each electrode of the second electrode group, wherein voltages having different amplitudes are applied from the driving device to each electrode of the first electrode group and the second electrode group. However, the direction of the electric field in the region surrounded by the two adjacent electrodes of the first electrode group and the two adjacent electrodes of the second electrode group and in the layer containing liquid crystal is An optical device characterized by being changed. 2. A voltage having a different phase is applied from the drive unit to each electrode of the first electrode group and the second electrode group, and the two adjacent electrodes of the first electrode group and the first electrode group are connected to each other. 2. The optical device according to claim 1, wherein the direction of the electric field direction in the region surrounded by the two adjacent electrodes of the second electrode group and in the layer containing the liquid crystal is periodically changed with time. . 3. A film which is electrically connected between at least one electrode of the first electrode group or at least one of the second electrode group and has a higher electric resistance than the respective electrodes and a uniform electric resistance. Claim 1 or Claim 2 characterized by having
The optical device described in. 4. The center of gravity of a region surrounded by two adjacent electrodes of the first electrode group and two adjacent electrodes of the second electrode group, and the center of gravity of the first electrode group. Adjacent two adjacent electrodes of the first electrode group and adjacent two electrode groups of the first electrode group in proportion to a distance between two adjacent electrodes and two adjacent electrodes of the second electrode group. 2. The amplitude of the voltage applied to the two electrodes to be increased is increased.
The optical device according to claim 3. 5. A cross section of two adjacent electrodes of the first electrode group and two adjacent electrodes of the second electrode group taken along a plane orthogonal to the plurality of parallel electrodes. ,
The two electrodes adjacent to each other in the first electrode group and the second electrode are arranged in a substantially square position.
The phase of the voltage applied to the two adjacent electrodes of the electrode group is shifted 90 degrees clockwise (or counterclockwise) in a cross section taken along a plane orthogonal to a plurality of parallel electrodes. The optical device according to any one of claims 1 to 4, which is characterized. 6. The optical device according to claim 1, wherein the liquid crystal layer is a liquid crystal layer having a positive dielectric anisotropy. 7. The surface shape of the surface of the transparent material layer in contact with the liquid crystal layer is a convex lens shape, a concave lens shape, a Fresnel lens shape, a prism array shape, a lens array shape, a lenticular lens shape, a diffraction grating shape, or the like. 7. The optical device according to claim 1, which is a curved surface shape in which 8. The dielectric constant of a layer of the transparent material and the dielectric constant of a layer including the liquid crystal layer have substantially the same value. The optical device described in.