JPH09258271A - Optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device in which a high speed driving is uniformly conducted, which is easily produced, and of which optical characteristics can be actively, continuously and periodically varied. SOLUTION: The device is provided with a transparent material layer 21 having a concave Fresnel lens shape and two transparent electrodes 23 and 24 that hold the layer including a refractive index variable material 22 in which dielectric index anisotropy is provided and a difference Δε, that is the difference between different dielectric indexes, reverses its sign at different driving frequencies f11 and f12. By supplying the frequency f11 or the voltage making the frequency f11 as the major frequency or the frequency f12 of the voltage making the frequency f12 as the major frequency by a driving device 25, the refractive index of the material 22 is varied by the changes in the frequency of the applied voltage and the optical characteristics of the device are speedingly varied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an
The present invention relates to an optical device capable of periodically and continuously changing optical properties of an optical device, such as a focal length of a lens, a deflection angle of a prism, and a divergence angle of a lenticular lens.

[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 voltage or the like are limited. Among them, as an optical device using a variable refractive index material, for example, the 1985 Scientific Research Grant Subsidy Research Result Report No. 598
There is a liquid crystal lens described in US Pat.

FIG. 1 shows the structure of the liquid crystal lens. A plano-concave lens 1 made of a polymer, glass, or the like, a transparent electrode 2 formed on the surface thereof, and a transparent electrode 2 formed on the transparent electrode 2 are shown. An alignment film 3 made of polyimide or the like, a liquid crystal (a normal nematic liquid crystal whose dielectric anisotropy does not reverse due to a difference in frequency) 4, a counter substrate 5 facing these, and a transparent electrode formed on the counter substrate 5 6, an alignment film 7 made of polyimide or the like formed on the transparent electrode 6, and a driving device 8 for driving these. here,
The alignment films 3 and 7 are in a homogeneous alignment state so that the liquid crystals 4 are aligned substantially in parallel.

When no voltage is applied between the transparent electrodes 2 and 6, the liquid crystal 4 is aligned so as to be substantially parallel to the counter substrate 5 by the action of the alignment films 3 and 7. in this case,
The liquid crystal 4 appears to have a larger refractive index than the plano-concave lens 1 with respect to the incident light 11 in the polarization state parallel to the alignment direction, so that the optical device as a whole functions as a plano-convex lens, It is focused like the emitted light 12.

On the other hand, when an appropriate voltage is applied between the transparent electrodes 2 and 6, the liquid crystal 4 is vertically aligned with respect to the counter substrate 5 and the plano-concave lens 1 by the action of the applied voltage. In this case, since the liquid crystal 4 appears to have almost the same refractive index as the plano-concave lens 1 for the incident light 11, the optical device as a whole exerts only the same effect as a simple glass plate, and the outgoing light 13 The light is emitted in almost the same direction as 11.

As described above, even in the conventional optical device,
It was possible to continuously change the optical properties of the plano-convex lens, for example, the focal length, as shown in FIG. 2 by the applied voltage.

[0007]

However, in the conventional optical device, the alignment of the liquid crystal 4 when no voltage is applied is performed only by the alignment regulating force of the alignment films 3 and 7. In such an optical device, the thickness of the liquid crystal 4 is several hundred μm.
m or more, the recovery time at the time of driving is shown in FIG.
As shown in (1), there was a drawback that the time was extremely slow as several seconds or more. Moreover, even if the applied voltage is increased, the recovery time is hardly improved, and there is no measure to shorten the recovery time.

As described above, when the liquid crystal 4 is aligned only by the alignment control force of the alignment films 3 and 7, the liquid crystal 4 is formed along the curved surface of the plano-concave lens 1 near the transparent electrode 2 as shown in FIG. The molecules 4a of the liquid crystal 4 are aligned. For this reason, the orientation of the liquid crystal partially tilts, the refractive index felt by the incident light approaches the refractive index of the plano-concave lens 1, and the change amount of the optical property becomes small, and the change amount of the optical property depends on the position of the lens. There was a drawback that distribution could occur.

When a voltage is applied to form the transparent electrode 2 on the surface of the plano-concave lens 1 or the like, an electric field is applied near the transparent electrode 2 in a form perpendicular to the surface, as shown in FIG. The liquid crystal 4 is oriented perpendicular to the surface. For this reason, the orientation of the liquid crystal is partially tilted, and a region is formed in which the refractive index felt by the incident light is considerably different from the refractive index of the plano-concave lens 1, and the incident light that should be transmitted with little or no deflection is partially formed. It has the disadvantage of being subject to deflection and the like.

Further, when the surface shape of the plano-concave lens 1 is more complicated, especially when it has deep grooves and sharp projections, it has a disadvantage that it is difficult to form a transparent electrode uniformly. In addition, there is a drawback that the alignment treatment of the alignment film for aligning the liquid crystal 4, for example, a rubbing treatment is difficult. In addition, the distance between the transparent electrodes differs depending on the position, as is clear from FIG. 1. Since the same voltage is applied to the transparent electrodes, there is a disadvantage that the insulating property is easily deteriorated and a short circuit is likely to occur in a narrow portion.

As described above, the conventional active optical device using the variable refractive index material has many disadvantages in practical use, such as a long recovery time, non-uniformity, problems in manufacturing or driving. I was

An object of the present invention is to provide an optical device which can be driven at high speed, has good uniformity, is easy to manufacture, and can continuously and periodically change optical properties.

[0013]

In order to achieve the above object, according to claim 1 of the present invention, a transparent material layer having a desired curved surface shape and a dielectric constant anisotropy and a different dielectric constant are provided. Of the refractive index variable substance having a property that the difference Δε between them has opposite signs at different driving frequencies f ₁ and f ₂ , and at least the layer of the transparent substance and the layer including the refractive index variable substance are sandwiched therebetween. Two transparent electrodes, the driving frequency f ₁ or a voltage having the driving frequency f ₁ as a main frequency and the driving frequency f ₂
Alternatively, an optical device including a driving device that supplies a voltage having a main frequency of the voltage between the transparent electrodes is proposed.

According to this device, the refractive index is changed by changing the frequency of the voltage applied to the refractive index variable substance, and thus the optical structure of the device constituted with the transparent substance layer having the desired curved surface shape. In order to change the optical properties, it takes a long time to change (recover) the refractive index when the voltage is off, as in the case of using a conventional material that changes the refractive index by turning the voltage on and off, and correspondingly high speed driving Unlike the device which could not be used, the device can be driven at a high speed and the force exerted by the electric field can always be utilized. Therefore, the speed can be further increased by increasing the electric field strength.

Further, according to this device, the refractive index of the variable refractive index substance is changed by the force exerted by the electric field, and the transparent electrode is not provided on the refractive index variable substance side of the transparent substance layer. In any of the above cases, the surface shape of the layer of the transparent material is less likely to be affected and the amount of change in optical properties can be made uniform as compared with the conventional device. Further, according to the present device, since the transparent electrode is not provided on the refractive index variable substance side of the transparent substance layer, it is not necessary to form a film on a portion having a complicated shape, and the manufacturing is easier than that of the conventional device. Become. Furthermore, according to the present device, since the transparent electrode is not provided on the refractive index variable substance side of the transparent substance layer, it is easy to make the distance between the transparent electrodes substantially the same, and moreover, between the transparent electrodes. Since the layer of the transparent material is always present, unlike the conventional device, the deterioration of the insulating property or the short circuit is unlikely to occur.

Further, in claim 2 of the present invention, the frequency f ₁
~ F _N (N ≥ 2) each having a main frequency V ₁ ~
The optical device according to claim 1, further comprising a driving device that sequentially supplies V _N with a constant application time and a constant cycle.

According to the present apparatus, the refractive index of the variable refractive index material periodically changes according to the frequency of the voltage V ₁ ~V _N, artificially becomes possible to take their intermediate values , The optical properties can be changed continuously.

According to claim 3 of the present invention, the frequency f _{1 is}
~ F _N (N ≥ 2) each having a main frequency V ₁ ~
The optical device according to claim 2, further comprising a driving device that temporarily stops the supply of V _N at a desired phase of the cycle and then restarts the supply when V _N is sequentially supplied at a constant application time and a constant cycle. .

According to the present device, the desired refractive index can be maintained while the voltage is stopped by utilizing the property of maintaining the state of the refractive index variable substance, and a rapid refractive index change which is not necessarily periodical change can be brought about. it can.

Further, according to a fourth aspect of the present invention, there is provided a variable refractive index material having a dielectric anisotropy and a property that a difference Δε of different dielectric constants has opposite signs at different driving frequencies f ₁ and f _2. A layer containing at least two transparent electrodes sandwiching the layer containing the variable refractive index material, and frequencies f _{1 to} f _N (N
There is proposed an optical device including a driving device that supplies a voltage obtained by superposing voltages V _{1 to} V _N , each having a main frequency of ≧ 2), between the transparent electrodes.

According to the present apparatus, continuously changing its refractive index by voltage ratio of a plurality of superimposed voltage V ₁ ~V _N of different frequencies from each other to be applied to the variable refractive index material, optical of this by the device Since the property is changed continuously, the refractive index changes (recovery) when the voltage is off, as in the case of using a conventional substance that changes the refractive index by turning the voltage on and off.
It takes a long time to drive, and accordingly, unlike devices that could not be driven at high speed, it is possible to drive at high speed and to bring about continuous changes, and since the force exerted by the electric field can always be used, the electric field strength is increased. By doing so, the speed can be further increased.

According to a fifth aspect of the present invention, a layer of a transparent material having a desired curved surface shape between at least two transparent electrodes is arranged adjacent to a layer containing a refractive index variable material. The described optical device is proposed.

According to the present device, the optical property of the device constituted by the variable refractive index material and the layer of the transparent material having the desired curved surface shape can be changed, and the refractive index is changed by the force exerted by the electric field. Since the refractive index of the variable substance is changed and the transparent electrode is not provided on the variable refractive index substance side of the transparent substance layer, the transparent substance layer is different from the conventional device in any state of the variable refractive index substance. It is difficult to be influenced by the surface shape of and the amount of change in optical properties is easily made uniform. Further, according to the present device, since the transparent electrode is not provided on the refractive index variable substance side of the transparent substance layer, it is not necessary to form a film on a portion having a complicated shape, and the manufacturing is easier than that of the conventional device. Become. Furthermore, according to the present device, since the transparent electrode is not provided on the refractive index variable substance side of the transparent substance layer, it is easy to make the distance between the transparent electrodes substantially the same, and moreover, between the transparent electrodes. Since the layer of the transparent material is always present, unlike the conventional device, the deterioration of the insulating property or the short circuit is unlikely to occur.

Further, according to claim 6 of the present invention, the frequency f ₁
~ F _N (N ≥ 2) each having a main frequency V ₁ ~
An optical device according to claim 4 or 5, which is provided with a drive device for temporarily stopping the supply at a desired time and then restarting the supply of the voltage with V _N superimposed.

According to the present device, the desired refractive index can be maintained while the voltage is stopped by utilizing the state maintaining property of the refractive index variable substance, and a rapid refractive index change which is not necessarily periodical change can be brought about. it can.

[0026] As index variable material of the present device, the opposite sign in the refractive index anisotropy and dielectric constant has anisotropy and difference Δε of different dielectric constants have different drive frequencies f ₁ and f ₂ 2
Frequency driven liquid crystals can be used.

Further, as the transparent electrode of this device, a substantially parallel transparent electrode can be used.

As the surface shape of the transparent material layer on the layer side containing the variable refractive index material of the present apparatus, a convex lens, a concave lens, a Fresnel lens, a prism array, a lens array, a lenticular lens, a diffraction grating, or any combination thereof is used. Curved surfaces can be adopted.

Further, by providing an alignment film for aligning the liquid crystal in one direction on the surface of the transparent electrode on the layer side containing the variable refractive index substance of the present device, the alignment of the liquid crystal becomes parallel to the alignment film. In a driving state, a uniform alignment state can be obtained in a wide domain region, a change in the refractive index of the liquid crystal can be efficiently transmitted to the incident light, and scattering caused by the liquid crystal being oriented in various directions or caused by this It is possible to prevent white turbidity.

Further, by arranging the surface of the liquid crystal having a more uniform orientation toward the light incident side, the polarization state of the incident light is made to coincide with the orientation direction, and the change in the refractive index of the refractive index variable substance is changed to the incident light. Can be efficiently communicated to.

Further, by arranging a plurality of the devices of the present invention provided with the alignment film in series so that the alignment directions of the alignment films are orthogonal to each other, various functions can be realized regardless of the polarization state of incident light. .

Further, by replacing any one of the transparent electrodes with an electrode that reflects at least a part of the incident light, it is possible to realize an active mirror or a half mirror whose optical characteristics change and other various optical devices.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an optical device according to the present invention will be described below. In the example shown below, the case where a Fresnel lens structure is mainly used as the surface of the transparent material layer is described, but a convex lens, a concave lens, a prism array, a lens array, a lenticular lens, a diffraction grating, or a curved surface obtained by combining these is used. It is obvious that the same effect can be expected even when it is included.

Further, in the following example, an example in which liquid crystal is mainly used as the refractive index variable substance will be described, but the same effect is expected even if another material having frequency dependence of dielectric anisotropy is used. It is clear that you can do it.

In the following example, the case where the liquid crystal and the transparent substance have substantially the same refractive index when the liquid crystal stands perpendicular to the transparent electrode will be described. However, the liquid crystal is parallel to the transparent electrode. It is obvious that the same effect can be expected even when the liquid crystal becomes almost equal when it becomes, or when the liquid crystal makes a certain angle with respect to the transparent electrode.

Further, in the following example, the case where the refractive index of the liquid crystal is generally larger than that of the transparent substance will be described. However, when the refractive index of the liquid crystal is generally smaller than that of the transparent substance, or It is clear that the same effect can be expected even when the value of the refractive index of the transparent substance is included in the variable range of the refractive index of.

[0037]

[First Embodiment] FIG. 6 shows an example of an embodiment of an optical device according to the present invention, which corresponds to claims 1, 7 and 8, and is a transparent polymer or glass having a desired curved surface shape. Layer 21 made of a transparent material, a variable refractive index material 22 made of a transparent material containing liquid crystal, and a plurality of ITO or SnO _x layers sandwiching the transparent material layer 21 and the layer containing the variable refractive index material 22. It is composed of transparent electrodes 23 and 24, and a drive device 25 for driving them.

Here, as one of the active optical devices,
For the purpose of providing a plano-convex lens with a variable focal length (positive focal length), for example, when the refractive index of the variable refractive index material 22 is larger than the refractive index of the transparent material layer 21, the refractive index variable The substance 22 may have a convex lens shape.
Therefore, the surface shape of the transparent material layer 21 on the refractive index variable material 22 side may be a concave Fresnel lens shape as illustrated. Of course, when the refractive index of the variable refractive index material 22 is smaller than the refractive index of the transparent material layer 21,
It is clear that the surface shape of the transparent material layer 21 on the refractive index variable material 22 side may be, for example, a convex Fresnel lens shape.

In this example, the refractive index variable substance 22 is
It has a refractive index anisotropy and a dielectric anisotropy. The dielectric anisotropy is the dielectric anisotropy Δ at the frequency f11.
ε (= ε‖ (dielectric constant parallel to the long axis of the molecule) −ε⊥ (dielectric constant perpendicular to the long axis of the molecule)) is positive, and the frequency f1
An example in which the dielectric anisotropy Δε is negative when 2 is used. Still refractive index anisotropy substantially equal to n _o (ordinary index) refractive index of the layer 21 of transparent material, n _e (extraordinary refractive index) is used generally greater example than the layer 21 of transparent material.

When an electric field of frequency f11 is applied between the transparent electrodes 23 and 24 from the driving device 25, Δε> 0. Therefore, the molecules of the refractive index variable substance 22 are oriented parallel to the electric field direction, that is, the transparent electrode 23. , 24 stands almost vertically.
Therefore, the refractive index of the variable refractive index material 22 is substantially the same as the refractive index of the transparent material layer 21 due to the relationship between the refractive index of the transparent material layer 21 and the refractive index variable material 22 described above. Therefore, the light 26 incident on the optical device of the present invention is transmitted as the outgoing light 27 with almost no change.

On the other hand, when an electric field of frequency f12 is applied between the transparent electrodes 23 and 24 from the driving device 25, Δε
Since <0, the molecules of the refractive index variable substance 22 are oriented perpendicular to the electric field direction, that is, substantially parallel to the transparent electrodes 23 and 24.
For this reason, the refractive index of the variable refractive index material 22 is higher than the refractive index of the transparent material layer 21 due to the relationship between the refractive index of the transparent material layer 21 and the refractive index variable material 22 described above. Here, since the portion of the refractive index variable substance 22 has a convex Fresnel lens shape, the present optical device has a convex Fresnel lens for the light 26 that is incident with the polarized light parallel to the long axis of the molecule of the refractive index variable substance 22. And functions as an output light 28 to be focused.

As described above, in this example, the refractive index variable substance 22 is used.
Among the optical properties of the optical device, the focal length of the lens can be changed by changing the refractive index of.

Further, in this example, the orientation state of the refractive index variable substance 22 is changed by the difference in the frequency of the applied voltage, and unlike the conventional example shown in FIGS. 1 to 5, mainly the force exerted by the electric field is used. By increasing the electric field strength, the rate of change can be extremely increased.

Further, since the orientation of the refractive index variable substance 22 is changed by the force exerted by the electric field and the transparent electrode 23 is not provided on the refractive index variable substance 22 side of the transparent substance layer 21, the refractive index variable substance 22 will eventually be removed. Fig. 1
Compared to the conventional examples shown in FIGS. 5 to 5, the surface shape of the transparent material layer 21 is less likely to be affected, and the change amount of the focal length can be made uniform more easily.

Further, since the transparent electrode 23 is not provided on the side of the variable refractive index material 22 of the transparent material layer 21, it is not necessary to form a film on a portion having a complicated shape, and the conventional example shown in FIGS. It is easier to manufacture in comparison.

Furthermore, since the transparent electrode 23 is not provided on the refractive index variable substance 22 side of the transparent substance layer 21, it is easy to make the distances between the transparent electrodes 23 and 24 substantially the same, and moreover, the transparent electrode 23. Since the transparent material layer 21 is always present between the layers 23 and 24, unlike the conventional example shown in FIGS.

As described above, in this example, the refractive index of the transparent material layer and the normal refractive index (or extraordinary refractive index) of the variable refractive index material such as liquid crystal are set to substantially equal values. You don't have to. That is, setting the refractive index to a substantially equal value is equivalent to setting the focal length to near infinity, but when it is difficult to set the refractive index to a substantially equal value in terms of material, or When it is difficult to use a material that can set the refractive index to almost the same value due to its relationship with other physical properties (dielectric anisotropy, refractive index anisotropy, temperature characteristics, miscibility with solvent, toxicity, etc.) Even so,
This is because the focal length can be set to near infinity simply by disposing another fixed-focus lens in front of and behind the present device for correction.

As described above, in this example, it is apparent that the driving speed can be increased, the uniformity, the ease of manufacture, and the driving problem can be solved as compared with the conventional example.

[0049]

[Second Embodiment] FIGS. 7 to 11 show an example of an embodiment of an optical device of the present invention corresponding to claims 2, 3, and 7. As a substance such as the refractive index variable substance used in the present invention, which exhibits a dielectric anisotropy different depending on the frequency, there is a two-frequency driving liquid crystal in a nematic liquid crystal.

FIG. 7 shows the dielectric anisotropy Δε of the dual frequency driving liquid crystal.
It shows a specific example of the drive frequency dependence of (= ε‖−ε⊥). Δε> 0 at low frequencies, but Δε becomes smaller as the frequency increases, and Δε at high frequencies.
<0. Here, when Δε> 0, the long axes of the molecules of the dual-frequency driving liquid crystal are oriented along the electric field, and when Δε <0, the long axes of the molecules are oriented perpendicular to the electric field. Accordingly, the refractive index of the two-frequency driving liquid crystal by simply changing the frequency changes almost binary (n _o and n _e), it can not be changed continuously refractive index (Incidentally, the alignment regulating force Although it can be changed by the balance with the force of the electric field, this has many drawbacks as described in the conventional example.).

FIG. 8 shows an example of a drive voltage waveform capable of continuously and periodically changing the refractive index of the dual frequency drive liquid crystal. As an example, two frequencies f21 having different signs of Δε
The case where (Δε> 0) and f22 (Δε <0) are used is shown. In the driving method of this example, for example, a voltage whose main frequency is the frequency f21 and a frequency f22 whose amplitude is equal to this voltage
Is applied with a constant duty ratio and a constant cycle.

When driven in this manner, the molecules of the two-frequency driving liquid crystal have a force for orienting their long axes along the electric field (when frequency f21 is applied) and a force for orienting their long axes perpendicular to the electric field (frequency f22). And (when applied) are felt alternately and periodically. If there is no other restraint force, in such driving, the liquid crystal abruptly changes digitally at the point where the frequency f21 and the frequency f22 are switched, and it is impossible to practically perform an analog operation. However, in reality, since there is viscosity and binding force as a crystal of liquid crystal, it balances with this alternating force applied periodically and enables a uniform and high-speed analog periodic alignment movement of liquid crystal over a wide area. And

However, in this driving method, the frequency f
21 and the frequency f22 are applied periodically for a certain period of time. For example, the frequency f21 and the frequency f22 are
Even if each of the electric fields is applied only once, the uniformity is impaired and the scattering becomes large, and the practicality as a variable focus lens becomes poor. Frequency f21 and frequency f2
By applying the electric field of 2 periodically for a certain period of time, the above-mentioned balance can be achieved and uniform operation can be performed over a wide area.

FIG. 9 shows an example of the above-mentioned continuous periodic movement of the liquid crystal, and here shows a case where a prism shape is used as the surface shape of the transparent material layer in the device shown in FIG. . Further, as the driving frequency, a low frequency f
21 and the high frequency f22, driving is performed as in the case of the rectangular wave in FIG. 8, and when the liquid crystal stands vertically with respect to the transparent electrode, the refractive index of the liquid crystal and the refractive index of the transparent substance become substantially equal to each other. , The case where the refractive index of the liquid crystal becomes larger than the refractive index of the transparent substance when it is substantially parallel to the transparent electrode. The horizontal axis is the time from the start of the high frequency f22 (normalized by the repeating period of f22 and f21), and the vertical axis is the deflection angle (degree) of the emitted light caused by the change in the refractive index of the prism structure and the liquid crystal.

From the figure, it has been clarified that the deflection angle of the emitted light exhibits a behavior close to a sine wave as the phase increases and can be changed in an analog manner. Further, the repetition cycle of the two frequencies (f22 and f21) in this example is almost 2
It is 0 ms, which means that according to the present invention, the recovery speed of the conventional example can be remarkably increased as compared with several seconds.

FIG. 10 shows the shape of the emitted light in the above example (instantaneous image at a certain point). This is a case where a circular spot light is incident as the incident light, and the emitted light has a similar spot shape. Since similar spot images are obtained at other times, it is clear that the liquid crystal makes almost uniform alignment motion in a wide region.

FIG. 11 shows another example of the driving voltage waveform capable of continuously changing the refractive index of the dual frequency driving liquid crystal.
Here, as in the case of FIG.
Two frequencies f21 (Δε <0) and f22 (Δε> 0)
, The frequency f of equal amplitude is shown in FIG.
While the case where two voltages of 21 and f22 are applied with a constant duty ratio and cycle is shown, here, the supply of voltage is temporarily stopped at a desired phase in the middle of the cycle,
After that, the case where the supply is restarted is shown.

When the voltage supply is temporarily stopped in this way,
The molecules of the two-frequency drive liquid crystal stop at the tilt corresponding to the stopped phase, and due to the alignment regulation force, fluctuations due to temperature, etc.,
The state is maintained until the orientation is gradually disturbed. The time until the orientation is disturbed by the orientation regulating force, fluctuations due to temperature, etc., usually takes several seconds or more. Therefore, if the voltage supply is restarted within this time, the disorder of the alignment can be kept small, and the small disorder of the alignment can be eliminated by restarting the voltage supply for a certain period of time. By driving in this way, a constant refresh time for fixing the above-mentioned turbulence is periodically required, but it is possible to bring about a fast refractive index change that is not necessarily a periodic change.

FIG. 12 shows an example of a device to which the above-described driving method is applied, and here, a device 32 in which many cells 31 are arranged in a matrix is shown. The driving sequence is as follows: (1) refresh operation for a certain period of time (periodic operation as shown in FIG. 8), and (2) each in a phase corresponding to the change in the refractive index required in each cell. The voltage supply to the cell is stopped. Then, in each cell, the refresh operation is started again after a predetermined time. By repeating such driving, the matrix device 32 including many cells can be driven.

Here, it goes without saying that the waveform of the driving voltage does not have to be a sine wave, and may be a rectangular wave or a sawtooth wave containing these frequencies as main frequencies. Also,
Obviously, the amplitude may have a periodic change. Furthermore, although two frequencies are used in this example, it goes without saying that more frequencies may be used.

Since the electric field is the main factor in the change in the refractive index by the driving method of this example, by increasing the amplitude,
It is possible to further increase the speed. That is, the cycle of the change of the refractive index by the present driving method can be accelerated from the conventional several seconds to several ms to several tens of ms or more. This speed is the case where the distance between the transparent electrodes in the structure as shown in FIG. 6 is increased to about several hundreds of μm, which shows that a sufficient speed can be obtained even with such a structure.

[0062]

Third Embodiment FIG. 13 shows an example of an embodiment of an optical device according to the present invention corresponding to claim 9. In the figure, the same components as those of the device of FIG. 6 are designated by the same reference numerals. That is, 2
Reference numeral 2 is a variable refractive index material, 23 and 24 are transparent electrodes, 25 is a driving device, and 41 is a layer of transparent material.

As described above, the variable refractive index material 22 has a refractive index anisotropy and a dielectric anisotropy, and the dielectric anisotropy is Δε> 0 at the frequency f11, It is assumed that Δε <0 at the time of f12. As for the refractive index anisotropy, n _o (normal refractive index) is substantially equal to the refractive index of the transparent material layer 41, and n _e (abnormal refractive index) is generally larger than that of the transparent material layer 41.

The surface shape of the transparent material layer 41 forms a convex lens, and when the frequency f11 is applied, the molecules of the refractive index variable material 22 are oriented parallel to the electric field direction, that is, with respect to the transparent electrodes 23 and 24. Stand almost vertically. Therefore, the refractive index of the variable refractive index material 22 is substantially the same as the refractive index of the transparent material layer 41 due to the relationship between the refractive index of the transparent material layer 41 and the refractive index variable material 22 described above. Therefore, the light 42 incident on the apparatus of this example is transmitted as the outgoing light 43 with almost no change.

On the other hand, when the frequency f12 is applied, the molecules of the refractive index variable substance 22 are oriented perpendicular to the electric field direction, that is, substantially parallel to the transparent electrodes 23 and 24. Therefore, the refractive index of the variable refractive index material 22 is higher than the refractive index of the transparent material layer 41 due to the relationship between the refractive index of the transparent material layer 41 and the refractive index variable material 22 described above. Here, since the portion of the refractive index variable substance 22 has a concave lens shape, it functions as a concave lens for the light 42 incident on the device of this example with polarized light parallel to the long axis of the molecule of the refractive index variable substance 22. , And diverges like outgoing light 44.

As described above, in this example, the refractive index variable substance 22 is used.
The focal length of the concave lens can be changed by changing the refractive index of.

[0067]

[Fourth Embodiment] FIG. 14 shows another example of the embodiment of the optical device of the present invention corresponding to the ninth aspect. Here, in the example of FIG. 13, a layer of a transparent material having a concave lens surface shape is used. An example using 45 is shown.

When a frequency f11 is applied to this device,
Similar to the example of FIG. 13, the refractive index of the variable refractive index material 22 is almost the same as the refractive index of the transparent material layer 45, and the incident light 42
Is transmitted as outgoing light 43 with almost no change.

On the other hand, when the frequency f12 is applied, the refractive index of the variable refractive index material 22 becomes larger than the refractive index of the transparent material layer 45, as in the example of FIG. Here, since the portion of the refractive index variable substance 22 has a convex lens shape, it functions as a convex lens for the light 42 incident on the device of this example with polarized light parallel to the long axis of the molecule of the refractive index variable substance 22. ,
It is focused like emitted light 46.

As described above, in this example, the refractive index variable substance 22 is used.
The focal length of the convex lens can be changed by changing the refractive index of.

[0071]

Fifth Embodiment FIG. 15 shows still another example of the embodiment of the optical device according to the present invention, which corresponds to claim 9. Here, in the example of FIG. 13, the transparent surface is a convex Fresnel lens. An example using a layer of material 47 is shown.

When the frequency f11 is applied to this device,
Similar to the example of FIG. 13, the refractive index of the refractive index variable material 22 is substantially the same as the refractive index of the transparent material layer 47, and the incident light 42
Is transmitted as outgoing light 43 with almost no change.

On the other hand, when the frequency f12 is applied, the refractive index of the variable refractive index material 22 becomes larger than the refractive index of the layer 47 of transparent material, as in the example of FIG. Here, since the portion of the refractive index variable substance 22 has a concave Fresnel lens shape, the concave Fresnel is incident on the light 42 which is incident on the device of this example as polarized light parallel to the long axis of the molecule of the refractive index variable substance 22. It functions as a lens and diverges like emitted light 48.

As described above, in this example, the refractive index variable substance 22 is used.
The focal length of the concave Fresnel lens can be changed by changing the refractive index of.

[0075]

[Sixth Embodiment] FIG. 16 shows still another example of the embodiment of the optical device according to the present invention, which corresponds to claim 9. Here, in the example of FIG. 13, a transparent material whose surface shape is a prism array is used. An example using the layer 49 of FIG.

When a frequency f11 is applied to this device,
Similar to the example of FIG. 13, the refractive index of the variable refractive index material 22 is almost the same as the refractive index of the layer 49 of transparent material, and the incident light 42
Is transmitted as outgoing light 43 with almost no change.

On the other hand, when the frequency f12 is applied, the refractive index of the variable refractive index material 22 becomes larger than the refractive index of the transparent material layer 49, as in the example of FIG. The light 42 that is incident with the polarized light parallel to the long axis of the molecule of 22 functions as a deflecting element that deflects the light according to the difference in the refractive index and the inclination of the prism, and deflects like the emitted light 50. .

As described above, in this example, the refractive index variable substance 22 is used.
The deflection angle of the deflecting element can be changed by changing the refractive index of.

[0079]

[Seventh Embodiment] FIG. 17 shows still another example of the embodiment of the optical device of the present invention corresponding to claim 9. Here, in the example of FIG. 13, a transparent lenticular lens is used as the surface shape. An example using a layer of material 51 is shown.

When the frequency f11 is applied to this device,
Similar to the example of FIG. 13, the refractive index of the variable refractive index material 22 is almost the same as the refractive index of the transparent material layer 51, and the incident light 42
Is transmitted as outgoing light 43 with almost no change.

On the other hand, when the frequency f12 is applied, the refractive index of the variable refractive index material 22 becomes larger than the refractive index of the transparent material layer 51, as in the example of FIG. Here, since the portion of the refractive index variable substance 22 has a convex lenticular lens shape, in this example, a convex lenticular lens is applied to the light 42 incident with the polarized light parallel to the long axis of the molecule of the refractive index variable substance 22. And diverges like emitted light 52.

As described above, in this example, the refractive index variable material 22 is used.
The focal length and divergence angle of the convex lenticular lens can be changed by changing the refractive index of.

[0083]

[Eighth Embodiment] FIG. 18 shows still another example of the embodiment of the optical device according to the present invention, which corresponds to claim 9. Here, in the example of FIG. 13, a transparent material whose surface shape is a diffraction grating is used. An example using the layer 53 of is shown.

When a frequency f11 is applied to this device,
Similar to the example of FIG. 13, the refractive index of the variable refractive index material 22 is almost the same as the refractive index of the layer 53 of transparent material, and the incident light 42
Is transmitted as outgoing light 43 with almost no change.

On the other hand, when the frequency f12 is applied, the refractive index of the variable refractive index material 22 becomes larger than the refractive index of the transparent material layer 53, as in the example of FIG. Here, since the portion of the refractive index variable substance 22 has a diffraction grating shape, this example functions as a diffraction grating with respect to the light 42 incident with the polarized light parallel to the long axis of the molecule of the refractive index variable substance 22. Then, it is diffracted like the emitted light 54.

As described above, in this example, the refractive index variable substance 22 is used.
The refractive index difference in the diffraction grating can be changed by changing the refractive index of, and the intensity of the diffracted light can be changed.

[0087]

[Ninth Embodiment] FIG. 19 shows an example of an embodiment of an optical device according to the present invention, which corresponds to claim 10. In FIG.
The same components as those of the device are denoted by the same reference numerals. That is,
Reference numeral 21 is a transparent material layer, 22 is a refractive index variable material, and 23, 2
4 is a transparent electrode, 25 is a driving device, and 61 is an alignment film.

The alignment film 61 is made of polyimide, PVA, PV
B, oblique vapor deposition SiO, etc., and is formed on the surface of the transparent electrode 24 on the refractive index variable substance 22 side. By subjecting the alignment film 61 to a treatment such as a rubbing method, the refractive index variable substance, here the liquid crystal 22, can be aligned in a fixed direction.

With such a configuration and processing, the liquid crystal 22
The liquid crystal 22 can be uniformly aligned in a wide domain region in a driving state in which is aligned parallel to the alignment film 61. This makes it possible to efficiently transmit the change in the refractive index of the liquid crystal 22 to the incident light, and prevent scattering and white turbidity caused by the liquid crystal 22 that are oriented in various directions.

On the surface of the transparent material layer 21 on the liquid crystal 22 side, an alignment film made of polyimide, PVA, PVB, oblique vapor deposition SiO or the like is applied, and an alignment treatment by a rubbing method or the like is applied to the liquid crystal 22. The orientation of the transparent substance on the layer 21 side can be improved. When the transparent material layer 21 is formed by a replica method (a method of replicating a mold of metal, glass, plastic, or the like), it is possible to directly orient the liquid crystal depending on the peeling direction. In this case, there is no need to apply a special film or to perform an orientation treatment on a surface having irregularities on the surface, so that the device can be easily manufactured.

It is also possible to vertically align the transparent substance layer 21 side of the liquid crystal 22 by applying a vertical alignment material on the surface of the transparent substance layer 21 on the liquid crystal 22 side.
In addition to the vertical alignment material, a material having a group such as fluorine and having a poor wettability with the liquid crystal material is applied on the surface of the transparent material layer 21 to form the transparent material layer 21 of the liquid crystal 22. It is also possible to make the side closer to the vertical alignment.
In these cases, it is only necessary to apply a film, and it is not necessary to perform an orientation treatment on a surface having irregularities on the surface, so that the device can be easily manufactured.

Further, the optical device of the present invention uses, for example, a dual frequency driving liquid crystal as the refractive index variable material, and polyimide, PVA, PVB, or PVB on the transparent electrode on the refractive index variable material side.
It is also possible to include a configuration including an alignment film made of oblique vapor deposition SiO or the like and not including the special alignment film as described above on the transparent material layer on the refractive index variable material side.

According to such a structure, in the vicinity of the transparent electrode on which the alignment film is arranged, the alignment film is subjected to an alignment treatment by a rubbing method or the like, so that the dual frequency drive liquid crystal (refractive index variable substance) in the vicinity thereof is added. ) Molecules can be oriented in a certain direction, but in the vicinity of the layer of transparent material, since no special alignment treatment is applied, the dual frequency drive liquid crystal shows different orientations depending on the location, and the incident light There is a possibility that the change in the refractive index cannot be sufficiently transmitted to the lens and the effect of the variable focus is not sufficiently expressed.

However, even in such a structure, this problem can be solved by, for example, making incident light incident from a direction in which the alignment of the liquid crystal is more uniform (for example, the side where the alignment film is formed). That is, by making the polarization state of the incident light coincide with the orientation direction, it becomes possible to efficiently transmit the change in the refractive index of the refractive index variable substance to the incident light. This is due to the optical rotation of the liquid crystal.If the orientation direction of the liquid crystal molecules changes slowly in comparison with the wavelength in the traveling direction of the incident light, the polarization direction of the incident light changes according to the change in the orientation direction of the liquid crystal molecules. It changes following (for example, when the alignment direction of the liquid crystal changes clockwise, the polarization direction also changes clockwise). For this reason, even if the orientation of the liquid crystal differs depending on the location near the transparent material layer, the incident light sufficiently feels a change in the refractive index.

According to such a structure, it is not necessary to apply a special film or to perform an orientation treatment on a surface having irregularities, so that the present apparatus can be easily manufactured.

[0096]

[Tenth Embodiment] FIG. 20 shows an example of an embodiment of an optical device according to the present invention. That is, 71 and 72 are optical devices provided with the alignment film described in FIG. 19, and by arranging them in series so that the alignment directions of the alignment films are orthogonal to each other, various functions are realized regardless of the polarization state of incident light. it can.

[0097]

[Eleventh Embodiment] FIG. 21 shows an example of an embodiment of an optical device according to the present invention corresponding to claims 4, 7, and 8. The refractive index variable substance 81 is made of a transparent substance containing liquid crystal, and the like. It is composed of a plurality of transparent electrodes 82 and 83 made of ITO or SnO _x sandwiching the refractive index variable substance 81, and a driving device 84 for driving these. Here, in this example, as one of the active optical devices, for example, a case of providing a light phase changing device is shown.

In this example, the refractive index variable substance 81 is
It has a refractive index anisotropy and a dielectric constant anisotropy. The dielectric constant anisotropy is the dielectric constant anisotropy Δ at the frequency f31.
ε (= ε‖ (dielectric constant parallel to the long axis of the molecule) -ε⊥ (dielectric constant perpendicular to the long axis of the molecule)) is positive, and the frequency f3
An example in which the dielectric anisotropy Δε is negative when 2 is used. Still refractive index anisotropy n _o (ordinary index) is used generally smaller examples than n _e (extraordinary refractive index).

When an electric field of frequency f31 is applied between the transparent electrodes 82 and 83 by the driving device 84, Δε> 0. Therefore, the molecules of the refractive index variable substance 81 are oriented in the direction parallel to the electric field direction, that is, the transparent electrode 82. , 83 stands almost vertically.
Therefore, the refractive index of the index variable material 81 is n _o, and the
A phase shift corresponding to the product of this refractive index and the layer thickness is introduced to the incident light 85.

On the other hand, when an electric field of frequency f32 is applied between the transparent electrodes 82 and 83 from the driving device 84, Δε
Since <0, the molecules of the refractive index variable substance 81 are in a direction perpendicular to the electric field direction, that is, substantially parallel to the transparent electrodes 82 and 83. Therefore, the refractive index of the refractive index variable substance 81 becomes n _e , and the refractive index becomes large. Therefore, the phase shift introduced to the incident light 85 becomes larger than that at the frequency f31.

Thus, in this example, the refractive index variable substance 81
Among the optical properties of the optical device, the phase shift of light can be changed by changing the refractive index of the optical device.

However, as described above, when Δε> 0, the long axis of the molecule is oriented along the electric field, and when Δε <0, the long axis of the molecule is oriented perpendicular to the electric field. than simply changing the intermediate values of the optical properties of the optical device, for example, can not be changed to an intermediate value of the corresponding phase shift in the refractive index n _o and n _e (Note that the alignment regulating force and the electric field force Although it can be changed depending on the balance, this has many drawbacks as described in the conventional example.)

22 and 23 show examples of drive voltage waveforms capable of continuously changing the optical characteristics. FIG. 22 shows a sine wave case and FIG. 23 shows a rectangular wave case. In the present example, the voltage Vs1 (in the case of a sine wave) or Vr1 (in the case of a rectangular wave) whose main frequency is the frequency f31 and the voltage Vs2 whose main frequency is the frequency f32
(For sine wave) or Vr2 (for rectangular wave),
A voltage Vss (in the case of a sine wave) or Vrr (in the case of a rectangular wave) superimposed at a certain voltage ratio is applied.

When driven in this way, the molecules of the dual-frequency driving liquid crystal have a force for orienting their long axes along the electric field (when frequency f31 is applied) and a force for orienting their long axes perpendicular to the electric field (frequency f32). A force in a direction opposite to (when applied) is sensed at the same time according to the voltage ratio. Therefore, the molecules are tilted from the direction of the electric field at an angle at which the forces in opposite directions are balanced according to the voltage ratio, and the refractive index can be continuously changed at high speed. In addition, this action is combined with the binding force of the liquid crystal as a crystal, which enables almost uniform and high-speed alignment movement of the liquid crystal over a wide domain region.

Here, it goes without saying that the waveform of the drive voltage does not have to be a sine wave or a rectangular wave, and may be a sawtooth wave containing these frequencies as main frequencies. Also,
Obviously, the amplitude may be changed with time. Furthermore, although two frequencies are used in this example, it goes without saying that more frequencies may be used.

Since the electric field is the main factor in the change in the refractive index by the driving method of this example, the amplitude can be increased to
It is possible to further increase the speed. That is, even when the distance between the transparent electrodes is as thick as about several 100 μm, the response speed of the change in the refractive index of the dual-frequency driving liquid crystal as the refractive index variable substance can be increased to about several tens ms or less.

[0107]

Twelfth Embodiment FIGS. 24 and 25 show an example of an embodiment of an optical device of the present invention corresponding to claims 5, 7, and 8. In the figure, the same components as those of the device of FIG. 21 are the same. It is represented by a sign. That is, 81 is a variable refractive index material, 82 and 83 are transparent electrodes, 84 is a driving device, and 86 is a layer of transparent material.

The transparent material layer 86 is made of a transparent polymer or glass having a desired curved surface shape, and the transparent electrode 8
It is arranged between 2 and 83.

Here, as one of the active optical devices,
For the purpose of providing a plano-convex lens with a variable focal length (positive focal length), for example, when the refractive index of the variable refractive index material 81 is generally larger than the refractive index of the transparent material layer 86, the refractive index variable The substance 81 may have a convex lens shape.
Therefore, the surface shape of the transparent material layer 86 on the refractive index variable material 81 side may be a concave Fresnel lens shape as shown in the figure. Of course, if the refractive index of the refractive index variable substance 81 is smaller than the refractive index of the transparent material layer 86,
It is clear that the surface shape of the transparent material layer 86 on the refractive index variable material 81 side may be, for example, a convex Fresnel lens shape.

In this example, the refractive index variable substance 81 is
It has a refractive index anisotropy and a dielectric anisotropy, and as the dielectric anisotropy, an example is used in which Δε> 0 at the frequency f31 and Δε <0 at the frequency f32. Still refractive index anisotropy substantially equal to the refractive index of the layer 86 of n _o transparent material, n _e is used generally greater example than the layer 86 of transparent material.

When an electric field of frequency f31 is applied between the transparent electrodes 82 and 83 from the driving device 84, Δε> 0. Therefore, the molecules of the refractive index variable substance 81 are oriented in the direction parallel to the electric field direction, that is, the transparent electrode 82. , 83 stands almost vertically.
Therefore, the refractive index of the variable refractive index material 81 is substantially the same as the refractive index of the transparent material layer 86 due to the relationship between the refractive index of the transparent material layer 86 and the refractive index variable material 81 described above. Therefore, the light 85 incident on the optical device of the present invention is transmitted as the outgoing light 87 with almost no change.

On the other hand, when an electric field of frequency f32 is applied between the transparent electrodes 82 and 83 from the driving device 84, Δε
Since <0, the molecules of the refractive index variable substance 81 are in a direction perpendicular to the electric field direction, that is, substantially parallel to the transparent electrodes 82 and 83.
Therefore, the refractive index of the variable refractive index material 81 is higher than the refractive index of the transparent material layer 86 due to the relationship between the refractive index of the transparent material layer 86 and the refractive index variable material 81 described above. Here, since the portion of the refractive index variable substance 81 has a convex Fresnel lens shape, the present optical device has a convex Fresnel lens for the light 85 incident with polarized light parallel to the long axis of the molecule of the refractive index variable substance 81. It functions as a lens and focuses like outgoing light 88.

As described above, in this example, the refractive index variable substance 81
Among the optical properties of the optical device, the focal length of the lens can be changed by changing the refractive index of.

However, as described above, the refractive index of the variable refractive index material cannot be changed to an intermediate value between n _o and n _e by simply changing the frequency. The optical properties of the optical device also cannot be changed to intermediate values.

The continuous change of the optical property is caused by a voltage V ₃₁ having a frequency f31 as a main frequency and a voltage V ₃₂ having a frequency f32 as a main frequency as shown in FIG. 22 or 23, for example. Can be applied by superimposing with a certain voltage ratio. At this time, the molecules of the liquid crystal driven by two frequencies are inclined from the direction of the electric field at an angle at which the forces in opposite directions are balanced according to the voltage ratio. This can bring about a rapid and continuous change in the refractive index. Also,
This action is combined with the binding force of the liquid crystal as a crystal, which enables a substantially uniform and high-speed alignment movement of the liquid crystal over a wide domain region, and can achieve a uniform change in optical properties.

FIG. 25 shows an example of continuous changes in the optical properties. In this example, a prism shape is used as the surface shape of the transparent material layer. The horizontal axis indicates the voltage ratio V ₃₂ / (V ₃₁ between the voltage V ₃₁ having the frequency f31 as the main frequency and the voltage V ₃₂ having the frequency f32 as the main frequency.
+ V ₃₂ ), and the vertical axis represents the deflection angle of the emitted light due to the change in the refractive index. From the figure, it can be seen that the deflection angle changes in an analog manner as the voltage ratio V ₃₂ / (V ₃₁ + V ₃₂ ) increases. The shape of the emitted light in this example is also the same as that shown in FIG. 10, and it is clear that the liquid crystal makes almost uniform alignment movement in a wide region.

Here, it goes without saying that the waveform of the drive voltage does not have to be a sine wave, and may be a rectangular wave or a sawtooth wave having these frequencies as main frequencies. Also,
Obviously, the amplitude may be changed with time. Furthermore, although two frequencies are used in this example, it goes without saying that more frequencies may be used.

Since the electric field is the main factor in the change in the refractive index by the driving method of this example, by increasing the amplitude,
It is possible to further increase the speed. That is, even when the distance between the transparent electrodes is as thick as about several 100 μm, the response speed of the change in the refractive index of the dual-frequency driving liquid crystal as the refractive index variable substance can be increased to about several tens ms or less.

Further, since the orientation of the refractive index variable substance 81 is changed by the force exerted by the electric field, and the transparent electrode 82 is not provided on the refractive index variable substance side of the transparent substance layer 86, the orientation of the refractive index variable substance is not limited. Even in the state, it is less affected by the surface shape of the transparent material layer 86 as compared with the conventional example shown in FIGS.

Further, since the transparent electrode 82 is not provided on the refractive index variable material side of the transparent material layer 86, it is not necessary to form a film on a portion having a complicated shape, and compared with the conventional example shown in FIGS. Therefore, it becomes easy to manufacture.

Furthermore, since the transparent electrode 82 is not provided on the refractive index variable material side of the transparent material layer 86, the transparent electrode 8
It is easy to make the distance between the transparent electrodes 82 and 83 substantially the same, and the transparent material layer 8 is always provided between the transparent electrodes 82 and 83.
6 is present, unlike the conventional examples shown in FIGS. 1 to 5, deterioration of insulation properties, short circuiting, etc. are unlikely to occur.

Thus, in this example, as compared with the conventional example,
It is apparent that the driving speed can be increased, the uniformity, the ease of manufacture, and the driving problem can be solved.

[0123]

[Thirteenth Embodiment] FIG. 26 shows an example of the embodiment of the optical apparatus according to the present invention. As an example, two frequencies f31 with different signs of Δε (Δε>
0) and f32 (Δε <0) are used, and a dual-frequency driving liquid crystal is used as the refractive index variable substance. Further, as an example, a case of using a sine wave and a case of using a rectangular wave are shown.

In the driving method of this example, the voltage having the frequency f31 as the main frequency and the voltage having the frequency f32 as the main frequency are superimposed and applied at a certain voltage ratio, and the voltage is supplied at a certain moment. Pause and then resume supply.

When the supply of voltage is once stopped in this way,
The molecules of the two-frequency driving liquid crystal stop at an inclination corresponding to the voltage ratio, and the state is maintained until the orientation is gradually disturbed due to the orientation regulating force, fluctuations due to temperature, and the like. The time until the orientation is disturbed by the orientation regulating force, fluctuations due to temperature, etc., usually takes several seconds or more. Therefore,
If the voltage supply is restarted within this time, the disorder of the orientation can be kept small, and the small disorder of the orientation can be eliminated by restarting the voltage supply for a certain period of time.
By driving in this way, a constant refresh time for fixing the above-mentioned disturbance is regularly required.
It is possible to bring about a fast refractive index change that does not require constant voltage application.

This driving method can also be applied to a device having many cells arranged in a matrix as shown in FIG. The drive sequence is as follows: (1) refresh operation for a certain period of time (operation as shown in FIG. 22 or 23), and (2) each in a phase corresponding to the change in the refractive index required in each cell. The voltage supply to the cell is stopped. Then, in each cell, the refresh operation is started again after a predetermined time. By repeating such driving, a matrix device including many cells can be driven.

Here, it goes without saying that the waveform of the drive voltage does not have to be a sine wave, and may be a rectangular wave or a sawtooth wave having these frequencies as main frequencies. Also,
Obviously, the amplitude may have a periodic change. Furthermore, although two frequencies are used in this example, it goes without saying that more frequencies may be used.

Since the electric field is the main factor in the change in the refractive index by the driving method of this example, by increasing the amplitude,
It is possible to further increase the speed. That is, the cycle of the change of the refractive index by the present driving method can be accelerated from the conventional several seconds to several ms to several tens of ms or more. This speed is shown in Figure 21.
Between the transparent electrodes in the structure shown in Fig.
This is a case where the thickness is moderate, which shows that a sufficient speed can be obtained even with such a structure.

In the fourth to tenth embodiments described above, the frequency f3 described in the eleventh and twelfth embodiments is also used.
1 may be driven by a voltage obtained by superimposing a voltage having a main frequency of 1 and a voltage having a main frequency of f32 at a certain voltage ratio. Further, the frequency f31 described in the thirteenth mode may be a main frequency. May be applied by superimposing a voltage having a frequency f32 and a voltage having a frequency f32 as a main frequency at a certain voltage ratio, further temporarily stopping the supply of the voltage, and then restarting the supply. .

[0130]

[Fourteenth Embodiment] In the above description, both of the two electrodes for driving the variable refractive index material are transparent electrodes, but it is also possible to use one of them as an electrode forming a mirror surface depending on the application. This is useful when, for example, an active mirror whose optical characteristics such as focal length and light deflection angle change is required. It is also useful to use this electrode as an electrode forming a half mirror and to use it as an active half mirror whose optical characteristics such as focal length and light deflection angle change.

FIG. 27 shows an example of an embodiment of an optical device of the present invention corresponding to claim 13. In the figure, the same components as those of the device of FIG. 6 are represented by the same symbols. That is, 2
Reference numeral 1 is a transparent material layer, 22 is a refractive index variable material, 23 is a transparent electrode, and 91 is an electrode.

The electrode 91 is an electrode forming a mirror surface, which is arranged in place of the transparent electrode 24 in the device of FIG.
For example, it is composed of a metal electrode made of an aluminum film or a chromium film.

In the above structure, when the frequency f11 is applied from the driving device (not shown), the refractive index of the transparent material layer 21 and the refractive index variable material 22 are substantially the same as in the first embodiment. Therefore, the incident light 92 incident from the transparent electrode 23 side is hardly changed and the incident light 92 is not changed.
And is reflected here and emitted from the transparent electrode 23 side.
It is emitted as 3.

On the other hand, when the frequency f12 is applied, it reaches the electrode 91 due to an optical effect corresponding to the change of the refractive index of the refractive index variable substance 22, such as a lens effect or a deflection effect, where it is reflected and reflected again. The transparent electrode 2 receives the same optical effect.
The emitted light 94 is emitted from the 3 side.

As described above, in this example, the refractive index variable substance 22 is used.
By changing the refractive index of, it is possible to realize a mirror with a variable focus and a mirror with a variable deflection angle.

[0136]

Fifteenth Embodiment FIG. 28 shows another example of the embodiment of the optical device of the present invention corresponding to the thirteenth aspect. Here, a half mirror is formed instead of the electrode 91 in the example of FIG. An example using the electrode 95 is shown. That is, the electrode 95
Consists of a laminated film of an ITO film and a thin film of metal, a multilayer film of a thin film of metal and an insulating film, and transmits part of the incident light and reflects the rest.

In the above structure, when the frequency f11 is applied from the driving device (not shown), the refractive index of the transparent material layer 21 and the refractive index variable material 22 are almost the same as in the first embodiment. Therefore, the incident light 92 incident from the transparent electrode 23 side is hardly changed, and
Reach A part of the light reaching the electrode 95 is transmitted through the electrode 95 and is emitted as emitted light 96a, and the remaining light is reflected and emitted from the transparent electrode 23 side as emitted light 96b.

On the other hand, when the frequency f12 is applied, it reaches the electrode 95 due to an optical effect corresponding to the change in the refractive index of the refractive index variable substance 22, for example, a lens effect or a deflection effect. Part of the light passes through the electrode 95, and the emitted light 9
7a is emitted, and the remaining light is reflected and again receives the same optical effect, and emitted from the transparent electrode 23 side as emitted light 97b.

As described above, in this example, the refractive index variable substance 22 is used.
By changing the refractive index of, it is possible to realize a lens and a mirror with variable focus, a transmissive optical element with a variable deflection angle, and a mirror at the same time. Further, when incident light is incident from the electrode 95 side, it is possible to simultaneously realize a lens having a variable focus and a simple mirror, a transmissive optical element having a variable deflection angle, a simple mirror and the like.

[0140]

[Sixteenth Embodiment] FIG. 29 shows still another example of the embodiment of the optical device according to the present invention, which corresponds to claim 13.
Here, an example is shown in which an electrode 98 forming a half mirror is used instead of the transparent electrode 23 in the example of FIG. That is, like the electrode 95, the electrode 98 is composed of a laminated film of an ITO film and a thin metal film, a multilayer film of a thin metal film and an insulating film, and transmits part of incident light and reflects the rest. To do.

In the above structure, when the incident light 92 enters from the electrode 98 side, a part of it is reflected by the electrode 98,
The rest is incident on the transparent material layer 21 and the refractive index variable material 22 side.

At this time, the frequency f
When 11 is applied, the refractive index of the transparent material layer 21 and the refractive index of the variable refractive index material 22 are substantially the same as in the case of the first embodiment, so that the incident light is hardly changed. To the electrode 91, where it is reflected. The reflected light reaches the electrode 98 again, and a part thereof is reflected again,
The rest is emitted to the outside, and the same process is repeated thereafter,
In this case, since no optical effect is exerted, the emitted light is simply the reflected light of the incident light 92.

On the other hand, when the frequency f12 is applied, the light transmitted through the electrode 98 reaches the electrode 91 under the optical effect according to the change of the refractive index of the refractive index variable substance 22, for example, the lens effect or the deflection effect. , Reflected here. The reflected light again receives the same optical effect and reaches the electrode 98, and a part of the reflected light is reflected again, and the rest is emitted to the outside.
The same process is repeated, but since the optical effect is received each time this process is repeated, it is emitted as the emitted light 99 to which a large optical effect is added according to the number of repetitions.

As described above, in this example, the refractive index variable substance 22 is used.
It is possible to realize a lens having a large number of focal points at the same time and a variable focal point thereof, an optical element having a large number of deflection angles at the same time and a variable deflection angle thereof, etc. At this time, the number of focal points and deflection angles that can be simultaneously provided can be substantially determined by adjusting the transmission / reflection ratio of the electrode 98.

[0145]

As described above, according to the first aspect of the present invention.
According to the method, the refractive index is changed by changing the frequency of the voltage applied to the refractive index variable substance, thereby changing the optical property of the device configured with the layer of the transparent substance having the desired curved surface shape. For this reason, it takes a long time to change (recover) the refractive index when the voltage is off, as in the case of using a conventional material that changes the refractive index by turning the voltage on and off, and the device that cannot be driven at high speed correspondingly. Unlike the above, since high-speed driving is possible and the force exerted by the electric field can always be utilized, the speed can be further increased by increasing the electric field strength. Also, the refractive index of the refractive index variable substance is changed by the force exerted by the electric field,
Moreover, since the transparent electrode is not provided on the refractive index variable substance side of the transparent substance layer, in any state of the refractive index variable substance, it is less affected by the surface shape of the transparent substance layer as compared with the conventional device, It is easy to make the amount of change in optical properties uniform. Further, since the transparent electrode is not provided on the refractive index variable material side of the transparent material layer, it is not necessary to form a film on a portion having a complicated shape, and the manufacturing is easier than that of the conventional device. Furthermore, since the transparent electrode is not provided on the refractive index variable material side of the transparent material layer, it is easy to make the distance between the transparent electrodes substantially the same, and moreover, the transparent material layer is always provided between the transparent electrodes. Since it exists, unlike the conventional device, deterioration of insulation property, short circuit, etc. are unlikely to occur.

According to the second aspect of the present invention, the refractive index of the refractive index variable substance periodically changes according to the frequency of each voltage, and pseudo intermediate values can be taken. Therefore, the optical properties can be continuously changed.

According to the third aspect of the present invention, the desired refractive index can be maintained while the voltage is stopped by utilizing the state maintaining property of the refractive index variable substance, and high-speed refraction that is not necessarily periodical change. It can bring about rate changes.

Further, according to claim 4 of the present invention, the refractive index is continuously changed by the voltage ratio of a plurality of superimposed voltages having different frequencies applied to the refractive index variable substance, whereby the optical index of the device is changed. In order to continuously change the physical properties, it takes a long time to change (recover) the refractive index when the voltage is off, as in the case of using a conventional substance that changes the refractive index by turning the voltage on and off. Unlike devices that could not be driven at high speed, it is possible to drive at high speed and to bring about continuous changes, and because the force exerted by the electric field can always be utilized, the speed can be further increased by increasing the electric field strength. it can.

Further, according to claim 5 of the present invention, it is possible to change the optical properties of the device in which the variable refractive index substance is formed together with the layer of the transparent substance having a desired curved surface shape, and the electric field is changed. The refractive index of the variable refractive index substance is changed by the force exerted by the transparent electrode, and the transparent electrode is not provided on the refractive index variable substance side of the transparent material layer. In comparison, it is less affected by the surface shape of the transparent material layer, and the amount of change in optical properties is easily made uniform. Further, since the transparent electrode is not provided on the refractive index variable material side of the transparent material layer, it is not necessary to form a film on a portion having a complicated shape, and the manufacturing is easier than that of the conventional device. Furthermore, since the transparent electrode is not provided on the refractive index variable material side of the transparent material layer, it is easy to make the distance between the transparent electrodes substantially the same, and moreover, the transparent material layer is always provided between the transparent electrodes. Since it exists, unlike the conventional device, deterioration of insulation property, short circuit, etc. are unlikely to occur.

Further, according to claim 6 of the present invention, a desired refractive index can be maintained while the voltage is stopped by utilizing the state maintaining property of the refractive index variable substance, and high-speed refraction that is not necessarily periodical change. It can bring about rate changes.

According to the tenth aspect of the present invention, in the driving state in which the liquid crystal is oriented in the direction parallel to the alignment film, a uniform alignment state can be obtained in a wide domain region, and the change in the refractive index of the liquid crystal It is possible to efficiently transmit the incident light, and it is possible to prevent scattering caused by the liquid crystal being oriented in various directions and white turbidity caused by the scattering.

According to the eleventh aspect of the present invention, the change in the refractive index of the refractive index variable substance can be efficiently transmitted to the incident light.

According to the twelfth aspect of the present invention, various functions can be realized regardless of the polarization state of incident light.

According to the thirteenth aspect of the present invention, it is possible to realize an active mirror or a half mirror whose optical characteristics change and other various optical devices.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an example of a conventional liquid crystal lens.

FIG. 2 is a diagram showing a relationship between a focal length and an applied voltage in the apparatus shown in FIG.

FIG. 3 is a diagram showing a relationship between a reaction time and an applied voltage in the apparatus of FIG.

FIG. 4 is a conceptual diagram of alignment of liquid crystal molecules by an alignment regulating force in the apparatus of FIG.

FIG. 5 is a conceptual diagram of the arrangement of liquid crystal molecules when a voltage is applied in the device of FIG.

FIG. 6 is a configuration diagram showing a first embodiment of the optical device of the present invention.

FIG. 7 is a diagram showing the relationship between the dielectric constant of liquid crystal and the frequency for explaining the second embodiment of the optical device of the present invention.

FIG. 8 is a drive voltage waveform diagram for explaining the second embodiment of the optical device of the present invention.

FIG. 9 is an explanatory diagram of a continuous periodic movement of liquid crystal for explaining the second embodiment of the optical device of the present invention.

FIG. 10 is a plane distribution graph of the brightness of emitted light for explaining the second embodiment of the optical device of the present invention.

FIG. 11 is another drive voltage waveform diagram for explaining the second embodiment of the optical device of the present invention.

FIG. 12 is a configuration diagram of a matrix device for explaining a second embodiment of the optical device of the present invention.

FIG. 13 is a configuration diagram showing a third embodiment of an optical device of the present invention.

FIG. 14 is a configuration diagram showing a fourth embodiment of an optical device of the present invention.

FIG. 15 is a configuration diagram showing a fifth embodiment of an optical device of the present invention.

FIG. 16 is a configuration diagram showing a sixth embodiment of an optical device of the present invention.

FIG. 17 is a configuration diagram showing a seventh embodiment of an optical device of the present invention.

FIG. 18 is a configuration diagram showing an eighth embodiment of an optical device of the present invention.

FIG. 19 is a configuration diagram showing a ninth embodiment of an optical device of the present invention.

FIG. 20 is a configuration diagram showing a tenth embodiment of an optical device of the present invention.

FIG. 21 is a configuration diagram showing an eleventh embodiment of an optical device of the present invention.

FIG. 22 is a drive voltage waveform diagram for explaining an eleventh embodiment of the optical device of the present invention.

FIG. 23 is a drive voltage waveform diagram for explaining an eleventh embodiment of the optical device of the present invention.

FIG. 24 is a configuration diagram showing a twelfth embodiment of an optical device of the invention.

FIG. 25 is an explanatory diagram of continuous changes in optical properties for explaining the twelfth embodiment of the optical device of the present invention.

FIG. 26 is a drive voltage waveform diagram for explaining an optical device according to a thirteenth embodiment of the invention.

FIG. 27 is a configuration diagram showing a fourteenth embodiment of the optical device of the present invention.

FIG. 28 is a structural diagram showing a fifteenth embodiment of the optical device of the present invention.

FIG. 29 is a configuration diagram showing a sixteenth embodiment of an optical device of the present invention.

[Explanation of symbols]

21, 41, 45, 47, 49, 51, 53, 86 ... Transparent material layer, 22, 81 ... Refractive index variable material, 23, 2
4, 82, 83 ... Transparent electrodes, 25, 84 ... Driving device, 6
1 ... Alignment film, 31 ... Cell, 71, 72 ... Optical device, 9
1, 95, 98 ... Electrodes.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location G02F 1/133 555 G02F 1/133 555 1/29 1/29

Claims (13)

[Claims] 1. A layer of a transparent material having a desired curved surface shape, and a property of having a dielectric anisotropy and a difference Δε of different dielectric constants having opposite signs at different driving frequencies f ₁ and f _2. A layer containing the variable refractive index material, and at least two transparent electrodes arranged between the transparent material layer and the layer containing the variable refractive index material; and the driving frequency f ₁ or the main frequency thereof. An optical device comprising: a drive device for supplying a voltage and a drive frequency f ₂ or a voltage having a drive frequency f ₂ as a main frequency between the transparent electrodes. 2. A method frequency f ₁ ~f N voltage _(N ≧ 2) of the main frequency respectively V ₁ ~V _N, further comprising a sequentially supplies drive at a constant application time and fixed cycle The optical device according to claim 1, wherein the optical device is an optical device. The 3. A frequency _{f 1 ~f N (N ≧ 2} ) the voltage V ₁ ~V _N whose main frequency, respectively, when sequentially supplying a constant application time and constant period, desired of the periodic The optical device according to claim 2, further comprising a drive device that temporarily stops the supply in a phase and then restarts the supply. 4. A layer containing a refractive index variable substance having a dielectric anisotropy and having a property that the difference Δε of different dielectric constants has opposite signs at different driving frequencies f ₁ and f ₂ , and the variable refractive index. and at least two transparent electrodes are disposed to sandwich the layer containing a substance, the frequency _{f 1 ~f N (N ≧ 2} ) , respectively between the main frequency to voltage V ₁ ~V _N the transparent electrode a voltage obtained by superimposing an An optical device comprising: 5. A layer of a transparent material having a desired curved surface shape between at least two transparent electrodes is disposed adjacent to a layer containing a variable refractive index material.
The optical device according to any one of the preceding claims. 6. When supplying the voltage obtained by superimposing the voltage V ₁ ~V _N for frequency f ₁ ~f N a _(N ≧ 2) as the main frequencies each, pauses the supply at a desired time, then, The optical device according to claim 4, further comprising a driving device that restarts. 7. A two-frequency driving liquid crystal having a refractive index anisotropy and a dielectric anisotropy, and having different dielectric constant differences Δε with opposite driving frequencies f ₁ and f ₂ as the refractive index variable substance. The optical device according to claim 1, 4 or 5, characterized in that. 8. The optical device according to claim 1, wherein the transparent electrodes are substantially parallel transparent electrodes. 9. The surface shape of the transparent material layer on the layer side including the variable refractive index material is a convex lens, a concave lens, a Fresnel lens, a prism array, a lens array, a lenticular lens, a diffraction grating, or a curved surface in which these are arbitrarily combined. The optical device according to claim 1, wherein the optical device is provided. 10. The optical device according to claim 7, wherein an alignment film for aligning liquid crystals in one direction is provided on the surface of the transparent electrode on the layer side containing the variable refractive index substance. 11. The liquid crystal display device according to claim 7, wherein the surface of the liquid crystal having a more uniform orientation is arranged toward the light incident side.
0. The optical device according to item 0. 12. An optical device comprising a plurality of the optical devices according to claim 10 or 11, arranged in series so that the alignment directions of the alignment films are orthogonal to each other. 13. The optical device according to claim 1, wherein one of the transparent electrodes is replaced with an electrode that reflects at least a part of incident light.