JP2012141552A - Liquid crystal cylindrical lens array and display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid crystal cylindrical lens array and a display device that operate at a low voltage, have high lens power and excel in optical characteristics even if the spacing between adjoining liquid crystal lenses is made narrower.SOLUTION: A liquid crystal cylindrical lens array comprises: a liquid crystal layer 31 in which liquid crystal molecules are oriented in a single direction, the layer being housed between a first substrate 11 having a transparent first electrode 21 and a second substrate 12 having a plurality of second electrodes having openings and third electrodes arranged in the openings respectively; and a double layer composed of a transparent insulating layer 51 and a transparent high resistance layer 41 and arranged in the openings and between the second electrodes and the third electrodes. A high resistance layer 42 having a resistance higher than that of the transparent high resistance layer 41 is further arranged overlapping an area in which the second electrodes are present.

Description

The present invention relates to a cylindrical lens array that has a simple structure and separates adjacent cylindrical lenses at a narrow interval, has a large lens power, and has excellent optical characteristics, and a display device including the cylindrical lens array.

Among liquid crystals that have liquid-like fluidity and anisotropy in electro-optical characteristics, nematic liquid crystals have an effective refractive index continuously from a value for almost extraordinary light to a value for ordinary light by applying a relatively low voltage. Various optical devices such as a liquid crystal lens of variable voltage type have been proposed by utilizing this feature.

For example, by using an electrode having a circular hole pattern with a diameter of several hundreds of microns and utilizing a liquid crystal molecular alignment effect due to an axially symmetric non-uniform electric field, a spatial parabolic refractive index distribution characteristic is obtained. Patent Document 1 discloses a method for obtaining a liquid crystal lens having Such a small liquid crystal lens having a diameter of millimeter or less is called a liquid crystal microlens.

In addition, as a configuration in which a liquid crystal lens based on the same structure is developed, visual recognition in two directions is achieved by arranging the electrode groups provided on the substrate surface sandwiching the liquid crystal layer so that the extending directions are orthogonal to each other on the two substrates. Patent Document 2 discloses a liquid crystal cylindrical lens that can switch between three-dimensional and two-dimensional display even at a position.

In the liquid crystal lens disclosed in these Patent Documents 1 and 2, since the electrode is in contact with the liquid crystal layer, if a lens having a large liquid crystal layer thickness and a large aperture diameter is formed, the opening of the electrode The effect of the generated non-uniform electric field does not reach the vicinity of the center of the opening. As a result, the spatial alignment distribution of the liquid crystal molecules necessary for obtaining the lens characteristics cannot be obtained. Therefore, in order to obtain the lens effect, the ratio of the aperture diameter to the thickness of the liquid crystal layer is about 2: 1 to 3: 1. There was a problem that had to be done.

Therefore, by arranging the electrode having an opening with a structure similar to the liquid crystal lens disclosed in Patent Document 1 so as to be at a certain distance from the liquid crystal layer without contacting the liquid crystal layer, Even if the diameter of the opening is increased, an axially symmetric non-uniform electric field can be generated up to the vicinity of the center of the opening. Based on this principle, Patent Document 3 discloses a method for maintaining the distance from the liquid crystal layer to the hole electrode by inserting an insulating layer between the liquid crystal layer and the hole pattern electrode. The conditions relating to the ratio between the aperture diameter of the hole pattern and the thickness of the liquid crystal layer that can obtain the best characteristics are relaxed, and a liquid crystal lens of an arbitrary size can be constructed regardless of the size of the aperture diameter and the thickness of the liquid crystal layer. It is shown.

Furthermore, in a liquid crystal lens in which an insulating layer is inserted between the liquid crystal layer and the hole pattern electrode, a transparent third electrode is arranged outside the hole pattern electrode or inside the pattern electrode and driven with two voltages. Patent Document 4 discloses a liquid crystal lens capable of changing the focal length over a wide range from a concave lens characteristic to a convex lens characteristic while maintaining good characteristics.

However, in the structure in which an insulating layer is provided in order to set the distance between the liquid crystal layer and the hole pattern electrode disclosed in Patent Documents 3 and 4, the insulating layer is disposed between the liquid crystal layer and the electrode. In particular, in order to obtain a lens having a large aperture, it is difficult to obtain a lens having a large aperture because the insulating layer is further thickened and a high voltage is required to obtain a lens having a large aperture. There was a problem. In addition, the thickness of the entire liquid crystal lens cannot be reduced due to the thickness of the insulating layer.

In order to solve this problem, a high-resistance medium is provided as a transparent high-resistance layer in the transparent insulating layer so that the non-uniform electric field extends to the vicinity of the center of the opening using the potential distribution of the high-resistance medium. This method is disclosed in Patent Document 5. Further, Non-Patent Document 1 reports a method for further lowering the voltage by using a transparent high-resistance thin film. These methods utilize the relay effect of the potential distribution by the high resistance layer, and reduce the driving voltage by reducing the effective thickness of the transparent insulating layer.

Based on the above principle, a cylindrical lens called a cylindrical lens is constituted by a liquid crystal lens having a structure in which liquid crystal oriented in one direction is sealed between a glass substrate with a transparent electrode and a glass substrate with a strip-shaped transparent electrode. be able to. In particular, by using the transparent insulating layer and the transparent high-resistance layer as described above, there is no restriction on the aperture diameter and the liquid crystal layer, and the liquid crystal layer having an arbitrary thickness can be used and driven at a low voltage. Have.

By adopting a lens array structure in which a large number of liquid crystal cylindrical lenses are arranged, a cylindrical lens array that can change the focal point, that is, a lenticular lens with variable focus, is configured and applied to a display device that realizes stereoscopic vision with the naked eye without using glasses. can do. Furthermore, by changing the lens effect by applying a voltage, switching between two-dimensional display and three-dimensional display can be performed.

When the liquid crystal cylindrical lens array is arranged on the front surface of the display device to perform three-dimensional display, it is desirable to increase the aperture diameter of each lens in order to obtain a bright display efficiently. Therefore, it is necessary to make the width of the electrode corresponding to the interval between the individual liquid crystal lenses as narrow as possible. In a liquid crystal lens array having a transparent insulating layer and a transparent high resistance layer, if the interval between the individual liquid crystal lenses is narrowed, the interaction between the liquid crystal lenses increases, making it difficult to obtain good lens characteristics. That is, when a constant voltage is applied, the problem is that the lens power decreases as the distance between the lenses decreases. Further, in order to obtain a lens power value similar to that when each liquid crystal lens is independent in the lens array, there is a problem that the distance between the lenses must be narrowed and the driving voltage value must be increased. there were.

JP-A-11-109303 Japanese Patent Laid-Open No. 2010-170068 JP 2004-4616 A JP 2006-91826 A JP 2008-203360 A

Hage, Wang, Masaru Uchida, Satoshi Yanase, Shingo Takahashi, Maki Yamaguchi, Susumu Sato (M. Ye, B. Wang, M. Uchida, S. Yanase, M. Yamaguchi and S. Sato) Low-Voltage-Driving Liquid Crystal Lens ", Japanese Journal of Applied Physics, October 2010, Vol. 49, pp. 100204-1-3 (2010).

Accordingly, an object of the present invention is to provide a liquid crystal cylindrical lens array that solves the above problems, operates at a low voltage, has a large lens power even when the interval between adjacent liquid crystal lenses is narrow, and has excellent optical characteristics, and An object of the present invention is to provide an image display device including a cylindrical lens array.

In order to solve the above problems, the present invention basically includes a first substrate having a transparent first electrode and a plurality of second electrodes facing the first electrode and having openings. And is accommodated between the second substrates on which the third electrodes are respectively arranged with respect to the respective openings through an insulating layer or in the openings with respect to the second electrodes. A liquid crystal layer in which liquid crystal molecules are aligned in one direction, a first voltage is applied between the first electrode and the second electrode, and the first electrode and the third electrode, The optical characteristics can be variably controlled by applying a second voltage that is independent of the first voltage between the opening, the second electrode, the third electrode, and the liquid crystal layer. A liquid crystal cylindrical array in which a double layer of a transparent insulating layer and a transparent high resistance layer is disposed between The resistance value of the high resistance layer is large in a range that overlaps the region where the second electrode exists and is equal to the width of the second electrode or narrower than the width of the second electrode. It is characterized by being a value.

The transparent high resistance layer may be removed in a range that overlaps the region where the second electrode is present and is equal to the width of the second electrode or narrower than the width of the second electrode.

The plurality of second electrodes are separated through slits, and different voltages can be applied to the separated electrodes.

A display panel having the liquid crystal cylindrical lens array disposed in front and a position sensor may be provided, and a voltage applied to the liquid crystal cylindrical lens array may be controlled by a signal related to a position by the position sensor to adjust characteristics of the display panel. The display panel may be a liquid crystal display panel, an organic EL display panel, a plasma display panel, or an electroluminescent display panel.

By the above means, in the cylindrical lens array using the liquid crystal, it is possible to provide a liquid crystal cylindrical lens array having a large effective optical phase difference amount and a large lens power and excellent separation between adjacent lenses. Provided is a three-dimensional display device capable of obtaining a good three-dimensional display image by using a cylindrical lens array.

FIG. 1A is a configuration explanatory view showing an embodiment of a liquid crystal cylindrical lens array according to the present invention, and FIG. 1B shows a second substrate and a second electrode of FIG. It is a top view of the 3rd electrode. FIG. 2 shows a liquid crystal cylindrical lens having a structure similar to that of FIG. 1 in which the resistance value of the transparent high resistance layer is constant over the entire range. The width of the opening is 100 microns and the thickness of the liquid crystal layer is 15 microns. When the resistivity of the high resistance layer is 80 Ωm, the distance between adjacent lenses, that is, the lens power is about 600 diopters (1 / m) in a state where the second electrode width and lens characteristics are good. It is the result of calculating | requiring the relationship of a required drive voltage (1st voltage V1). Here, the second voltage V2 = 0.5 volts (constant). The voltage is a sine wave having a frequency of 1 kHz and is represented by an effective value. FIG. 3 shows a liquid crystal cylindrical structure in the case where the resistance value of the high resistance layer is set to a value larger by 6 digits in a range narrower than the width of the second electrode in the configuration shown in FIG. This is the result of determining the relationship between the distance between adjacent lenses, that is, the width of the second electrode and the lens power. Here, the driving voltage is a sine wave having a frequency of 1 kHz, and the first voltage V1 = 3 volts (effective value) and the second voltage V2 = 0.5 volts (effective value). FIG. 4 is an explanatory diagram showing a configuration of an embodiment of a liquid crystal cylindrical lens array configured such that a plurality of second electrodes are separated through slits and can be applied with different voltages. FIG. 5 shows an optical phase difference distribution obtained by simulation in the liquid crystal cylindrical lens having the configuration shown in FIG. 4 when V1a = 4.5 volts, V1b = 1.5 volts, and V2 = 0.5 volts are applied. It is a result.

The point which this invention paid attention to is devised so that each of a plurality of problems found in the prior art can be solved together. The following table is provided to clarify the above problems.

As can be seen from Table 1, in the techniques of Patent Document 1 and Patent Document 2, it is a problem to eliminate restrictions on the aperture diameter and the thickness of the liquid crystal layer and to widen the variable range of the lens power. In Patent Document 3, it is a problem to reduce the drive voltage, widen the variable range of lens power, and improve separation between adjacent lenses. In Patent Document 4, it is a problem to reduce the drive voltage and improve the separation between adjacent lenses. In Patent Document 5 and Non-Patent Document 1, it is a problem to improve separation between adjacent lenses. In light of the above, it is an object of the present invention to obtain a liquid crystal cylindrical lens array that operates at a low voltage, has a wide variable range of lens power, and has good separation between adjacent lenses. Next, embodiments of the present invention will be described in detail with reference to the drawings. The basic configuration is described in FIG.

FIG. 1A shows a configuration in which a basic configuration of an element operating as a liquid crystal cylindrical lens is viewed from a cross section as an embodiment of the liquid crystal cylindrical lens array of the present invention. The transparent first electrode 21 is formed on the first substrate 11 and constitutes a liquid crystal cell by overlapping the second substrate 12 via a spacer (not shown) for maintaining a predetermined thickness. Between the 1st board | substrate 11 and the said 2nd board | substrate 12, the liquid crystal layer 31 in which the liquid crystal molecule accommodated in one direction was accommodated so that the 1st electrode 21 might be opposed was provided.

An alignment film 61 having an effect of aligning liquid crystal molecules in one direction is disposed on the surface of the first substrate 11 in contact with the liquid crystal layer 31.

In addition, a plurality of second electrodes 221 to 223 and third electrodes 231 and 232 are formed in an opening between the second electrodes on the side facing the liquid crystal layer of the second substrate 12. Further, a transparent insulating layer 51, a transparent first high resistance layer 41 as a transparent high resistance layer, and an alignment film 62 are laminated. The transparent high resistance layer 41 is not connected to any electrode and does not directly apply a voltage. Further, a second high resistance layer having a resistance value that is larger than the resistance value of the first high resistance layer 41 in place of the first high resistance layer 41 so as to overlap the region where the second electrodes 221 to 223 exist. 42 is arranged.

The alignment film 61 and the alignment film 62 are rubbed in one direction so that the director corresponding to the major axis direction of the liquid crystal molecules is aligned at an angle of about 1 degree from the substrate surface called the pretilt angle. It is in a state.

FIG. 1B is a plan view of the liquid crystal cylindrical lens array of FIG. 1A. A plurality of second electrodes 221, 222, 223 formed on the second substrate 12 are shown in FIG. A first voltage V 1 is applied from the first power supply 81 between the first electrode 21 and the first electrode 21. A second voltage V2 can be applied from the second power source 82 between the first electrode 21 and the third electrodes 231 and 232.

Here, a case will be described in which the transparent insulating layer 51, the transparent first high-resistance layer 41, and the second high-resistance layer 42 are excluded from the configuration shown in FIG. As an initial state, consider a case where the director corresponding to the major axis direction of the liquid crystal molecules is in a homogeneous orientation in which the director is inclined in one direction at a pretilt angle of about 1 degree with respect to the alignment film surface attached to the electrode surface. . When V1 and V2 are 0, that is, when no voltage is applied, the effective refractive index in the liquid crystal layer is uniform in the in-plane direction of the substrate.

Next, when V1 and V2 are appropriately set so that an electric field exceeding the threshold value of the liquid crystal is applied, the director of the liquid crystal rises at an angle perpendicular to the alignment film surface where the electric field strength is large. When the electric field strength is weak, the angle at which the director rises from the alignment film surface becomes small. When the angle at which the director is tilted with respect to the alignment film surface is increased, the effective refractive index is decreased. As the angle is decreased, the effective refractive index is increased. That is, depending on the electric field strength, the angle formed by the director with respect to the alignment film surface is different, and as a result of being distributed with respect to the alignment film surface, that is, the substrate surface, a state in which the effective refractive index is distributed is obtained.

Between the second electrodes 221, 222, 223 and the first electrode 21, which are arranged in a strip shape at regular intervals, the first power supply 81 applied a voltage above the threshold value from the second power supply 82. When the first voltage V1 larger than the value of the second voltage V2 is applied, the electric field between the second electrodes 221 and 222 and between the 222 and 223 near the center is the smallest, The electric field distribution is such that the electric field gradually increases toward the electrode. By this electric field distribution, directors corresponding to the major axis direction of the liquid crystal molecules are aligned in the electric field direction, so that the effective refractive index of the liquid crystal gradually decreases from the center between the second electrodes toward the electrode portion. A refractive index distribution characteristic is obtained, and the liquid crystal layer has a convex lens function that converges on incident light polarized in the direction of the director of the liquid crystal. Further, the focal length of the convex lens can be continuously varied by fixing the first voltage and adjusting the second voltage.

On the contrary, when the second voltage is made larger than the first voltage, the electric field distribution is such that the electric field is greatest at the intermediate portion of the second electrode and gradually decreases toward the second electrode. The refractive index distribution characteristic is such that the effective refractive index gradually increases from the center toward the periphery, and the liquid crystal layer has a concave lens function that diverges with respect to incident light polarized in the direction of the director of the liquid crystal. When the concave lens is operated, the focal length can be continuously varied by fixing the second voltage and adjusting the first voltage.

Further, when the first voltage V1 and the second voltage V2 are adjusted so that the refractive index distribution shape is a quadratic function (parabolic) between the second electrodes, a cylindrical lens characteristic with small aberration is obtained. be able to. Details of the operation principle of these liquid crystal lenses are disclosed in Patent Documents 3 and 4.

As shown in FIG. 1, by providing the transparent insulating layer 51, the transparent high resistance layer 41, etc., the relay effect of the potential distribution by the high resistance layer can be used, so the thickness of the transparent insulating layer is reduced. Even with this, it is possible to construct a lens having good optical characteristics. The operation principle of a liquid crystal lens having a transparent insulating layer and a high resistance layer is reported in Patent Document 5 and Non-Patent Document 1.

Next, specific examples will be described. In FIG. 1, a first substrate 11 is a transparent glass plate having a thickness of 300 μm, and a transparent first electrode 21 made of indium tin oxide (ITO) is formed on the inner surface side in contact with the liquid crystal layer 31. ing. The second substrate 12 is a glass plate having a thickness of 300 μm, and a plurality of strip-like ITO electrodes 221 to 223 serving as second electrodes are formed on the side of the second substrate in contact with the liquid crystal layer 31. Between the two electrodes, strip-like ITO electrodes 231 and 232 are formed as third electrodes. A first voltage V <b> 1 is applied from the first power supply 81 between the second electrodes 221 to 223 and the first electrode 21, and between the third electrodes 231, 232 and the first electrode 21. The second voltage V2 is applied from the second power source 82.

In particular, in this liquid crystal lens, the first high resistance layer 41 is formed as a transparent insulating layer 51 and a transparent high resistance layer between the liquid crystal layer 31 and the second substrate 12 having a plurality of second electrodes and third electrodes. It is arranged. Furthermore, the resistance value of the high resistance layer is within a range that overlaps the region where the second electrodes 221, 222, and 223 exist and is equal to the width of the second electrode or narrower than the width of the second electrode. A second high resistance layer 42 having a large value is disposed. When the second electrode is made of a material that does not transmit light, such as a metal thin film, the second high resistance layer is not necessarily transparent. Further, MLC-6080 (manufactured by Merck & Co., Inc.) is used as the liquid crystal material of the liquid crystal layer 31, and a polyimide film of about 0.15 microns is used as the alignment films 61 and 62 on the surface of the electrode and high resistance layer sandwiching the liquid crystal layer. After being applied to the thickness and stabilized by heat treatment, rubbing treatment is performed in one direction.

When the rubbing treatment is performed, it is generally known that the major axis direction of the liquid crystal molecules is in an alignment state inclined by a small angle of about several degrees called a pretilt angle with respect to the rubbing direction. Therefore, when the rubbing directions with respect to the alignment film on the opposite substrate are processed in opposite directions (referred to as anti-parallel), the liquid crystal molecules are uniformly aligned with a pretilt angle on the substrate surface. Yes.

In order to maintain the liquid crystal layer 31 at a predetermined thickness, a spherical spacer having a diameter of 15 μm (not shown) dispersed in an adhesive is used, and although not shown, the periphery of each substrate is liquid crystal by an adhesive. Is sealed.

As the transparent insulating film 51, an amorphous quartz film having a thickness of 0.5 microns is used. However, the transparent insulating film 51 may be thin as long as insulation is maintained. Moreover, it can be used even if it is an insulating material or a material with a large dielectric constant irrespective of other organic type and inorganic type.

As the transparent first high-resistance layer 41, a zinc oxide thin film having a thickness of about 25 nm is used. However, a resin-based conductive film in which conductive fine particles are dispersed, for example, a conductive film TWH manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd. -1 (1 μm) can also be used. The resistance of the zinc oxide-based high resistance layer used in this example was about 1 MΩ to 100 GΩ as a surface resistance value. Similarly, a zinc oxide-based thin film can be used as the second high resistance layer having a resistance value larger than that of the first high resistance layer. In addition, as a material constituting these high resistance layers, other inorganic thin films, for example, transparent thin films such as ITO, titanium oxide, zinc sulfide, or a mixed system of these materials set to an optimum resistance value are used. It can also be used.

The distance between the openings between the second electrodes is 100 microns, and a third electrode having a width of 92 microns is disposed through a slit having a width of 4 microns. The first voltage V1 and the second voltage V2 are both 1 kHz sine waves and in phase, and the light source is a combination of a white light source and an interference filter (transmission wavelength 633 nm).

FIG. 2 is a configuration similar to FIG. 1, and in the liquid crystal cylindrical lens in which the second high resistance layer is not provided and the resistance value of the transparent high resistance layer is the same in the entire range, the width of the opening is set. When the thickness of the liquid crystal layer is 15 microns and the resistivity of the high resistance layer is 80 Ωm, the distance between adjacent lenses, that is, the width of the second electrode and the lens characteristics of the liquid crystal cylindrical lens are good. This is the result of obtaining the relationship of the drive voltage (first voltage V1) required when the lens power corresponding to the reciprocal of the focal length is adjusted to about 600 (diopters, 1 / m). Here, the second voltage V2 = 0.5 volts (constant). The voltage is a sine wave with a frequency of 1 kHz, and the voltage is shown as an effective value. It can be seen that the required first voltage increases rapidly as the width of the second electrode becomes narrower, and the driving voltage increases to 80 volts when the width of the second electrode is 2 microns. Here, since the width of the second electrode is equal to the interval between adjacent lenses, if the interval between the liquid crystal cylindrical lenses is reduced, the required drive voltage increases rapidly. In other words, when the driving voltage is kept constant, there arises a problem that the distance between the liquid crystal cylindrical lenses becomes narrow and the lens power rapidly decreases.

FIG. 3 shows that the resistance value of the second high resistance layer is 6 orders of magnitude larger than the width of the second electrode so as to overlap the region where the second electrode exists in the configuration of FIG. In the liquid crystal cylindrical lens, the distance between adjacent lenses, that is, the relationship between the width of the second electrode and the lens power is obtained. Here, the driving power was a sine wave with a frequency of 1 kHz, and the lens power was determined when the first voltage V1 = 3 volts and the second voltage V2 = 0.5 volts were constant. FIG. 3 shows that even when the width of the second electrode, that is, the interval between adjacent cylindrical lenses is narrowed, the lens power is almost constant at 600 (diopter, 1 / m) or more.

In the present embodiment, the resistance value of the second high resistance layer is set to a value larger than the resistance value of the first high resistance layer in a range overlapping the region where the second electrode corresponding to the interval between adjacent cylindrical lenses is present. Thus, there is no interaction between the lenses, and the separation state between the lenses is good, so that the lens power does not decrease even if the distance between the lenses is narrowed, and the lens can be driven at a low voltage. Note that the width of the region where the resistance value is increased, that is, the width of the second high resistance layer may be narrower than the width of the second electrode. In that case, the accuracy of alignment in the element manufacturing process is eased. This is advantageous. Although only two liquid crystal cylindrical lenses are shown in FIG. 1, it is possible to easily realize a lens array in which a large number of these lenses are arranged.

In the present embodiment, the case where the resistance value of the transparent high resistance layer is increased in the region where the second electrode adjacent to each cylindrical lens exists is shown. However, the transparent high resistance layer is removed in this region. Thus, separation between adjacent lenses can be performed in the same manner as when the resistance value is increased. The removal of the transparent high-resistance layer corresponds to the case where the resistance value of the transparent high-resistance layer is very large, so that the effect of separation between the lenses can be increased, but the electric field distribution is Since it becomes steep, there is a problem that a disclination defect due to discontinuity of liquid crystal molecule alignment easily occurs.

Other embodiments will be specifically described. In FIG. 4, the second electrodes 221, 222, and 223 are each divided into two via slits, and different voltages can be applied to the separated electrodes 221 a, 221 b, 222 a, 222 b, 223 a, and 223 b, respectively. It is configured. In this embodiment, a voltage V11 is applied from the power source 81a between the separated electrodes 221a, 222a, 223a and the first electrode 21, and the electrodes 221b, 222b, 223b and the first electrode paired with these electrodes are applied. 21 is configured such that the voltage V12 can be applied from the power source 81b. The resistance value of the high resistance layer is large in a range that overlaps the region where the divided second electrode exists and is equal to the width of the second electrode or narrower than the width of the second electrode. The second high resistance layer 42 is disposed.

When the value of V11 is equal to the value of V12, the optical phase difference distribution generated in the liquid crystal layer 31 has a symmetric shape in the opening between the second electrodes. On the other hand, when the value of V11 is different from the value of V12, the optical phase difference distribution at the opening between the electrodes is asymmetrical, and the effect that the incident height is deflected toward the larger effective refractive index while passing through the liquid crystal layer. Is obtained.

FIG. 5 shows a liquid crystal cylindrical lens having the structure shown in FIG. 4, in which the thickness of the liquid crystal layer is 40 μ, and when V1a = 4.5 volts, V1b = 1.5 volts, and V2 = 0.5 volts are applied. It is the result of having calculated | required optical phase difference distribution by simulation. Since the values of the voltages applied to the two divided second electrodes are different from each other, the optical phase difference distribution characteristics are asymmetric distributions. As a result, incident light is deflected while passing through the liquid crystal layer. It will be. In this case, the result was that incident light was deflected about twice after passing through the liquid crystal layer. This deflection angle can be continuously adjusted by varying each voltage. Furthermore, the focal distance as a convex lens can be continuously varied by adjusting the first voltage.

In Example 1 and Example 2 above, the resistance value of the second high resistance layer in the boundary region where each lens is adjacent, that is, the region where the second electrode is present, is the resistance of the first transparent high resistance layer. Although the case where the value is larger than the value is shown, separation between devices can be similarly performed by providing a slit from which the second high resistance layer is removed. Note that removing the second high-resistance layer and providing a slit corresponds to the case where the resistance value of the second high-resistance layer is very large, and therefore, the effect of separating devices is made stronger. However, since the electric field distribution becomes steep, there is a problem that a disclination defect due to discontinuity of liquid crystal molecule alignment is likely to occur.

Instead of a transparent high resistance layer, a transparent ferroelectric layer can also be used. In this case, by using a material having a low dielectric constant in the region where the second electrode is present, separation between adjacent lenses can be performed as in the case of using the transparent high resistance layer. As the ferroelectric material, barium titanate, lithium niobate, potassium tantalate niobate, or the like can be used. When a thin film made of a ferroelectric material is used as such a transparent impedance layer, there is an advantage that the frequency dependence of the driving voltage is eliminated.

Furthermore, another embodiment will be described. The liquid crystal cylindrical lens array was disposed on the front surface of the liquid crystal display panel, and a position sensor for detecting the position of an observer or the like was further disposed. By using this position sensor, the display characteristics of the display device can be adjusted by controlling the voltage of the liquid crystal cylindrical lens array in accordance with a signal related to information such as the distance and direction from the display panel of the observer.

When the liquid crystal cylindrical lens array of Example 1 is used, a distance sensor is used as a position sensor, and the focal length of the liquid crystal cylindrical lens is variably controlled using a signal related to the distance between the observer and the display panel. Even if a person approaches or leaves the display panel

When the liquid crystal cylindrical lens array of Example 2 is used, the left and right deflection characteristics can be obtained in addition to the focal length, so that the control effect is further effective. That is, using a position sensor that can detect not only the distance between the display panel and the observer but also information related to the orientation of the observer, and using signals related to the distance and orientation of the observer and the display panel, the liquid crystal cylindrical lens By variably controlling the focal length and the deflection angle, it is possible to adjust so as to always obtain the best three-dimensional display characteristics even when the observer moves.

When configuring a three-dimensional display device using a liquid crystal cylindrical lens array and a position sensor, the display panel is a liquid crystal display panel, an organic EL display panel, a plasma display panel, or an electroluminescent display panel. Can be used.

As a specific example, a liquid crystal lens having a plurality of strip electrodes has been described. However, the present invention is not limited to a liquid crystal lens, and various optical devices using pattern electrodes of other shapes. It can also be applied to devices and the like.

Further, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment. Moreover, it can also be set as the structure which arranged the electrode in the direction orthogonal to each of two board | substrates.

Furthermore, by dividing the liquid crystal layer into two layers so that the alignment directions of the liquid crystal molecules are orthogonal to each other, it is possible to construct a liquid crystal cylindrical lens array capable of dealing with natural light.

The liquid crystal cylindrical lens array of the present invention differs from a normal passive lens array in that a lens is applied as an optical lens by variably controlling the effective refractive index of liquid crystal as a medium by applying a voltage between electrodes. Since it has the function of changing the power, that is, the focal length, and continuously adjusting the deflection angle with respect to the incident light, not only the 3D display device but also the lens of the imaging unit used as a visual function in the robot, etc. Various applications are possible.

DESCRIPTION OF SYMBOLS 11 ... 1st board | substrate, 12 ... 2nd board | substrate, 21 ... 1st electrode, 221-223 ... 2nd electrode, 231, 232 ... 3rd electrode, 31 ... Liquid crystal layer, 41 ... First transparent high resistance layer, 42 ... Second high resistance layer, 51 ... Transparent insulation layer, 61, 62 ... Alignment film, 81, 82 ..Drive power supply.

Claims (5)

A first substrate having a transparent first electrode, and a plurality of second electrodes facing the first electrode and having an opening, and an insulating layer is provided for each of the openings, or A liquid crystal layer in which liquid crystal molecules are aligned in one direction and is accommodated between second substrates each having a third electrode disposed at a distance from the second electrode in the opening; A first voltage is applied between the first electrode and the second electrode, and a second voltage independent of the first voltage is applied between the first electrode and the third electrode. In addition, the optical characteristics can be variably controlled, and a double layer of a transparent insulating layer and a transparent high resistance layer is disposed between the opening, the second electrode, the third electrode, and the liquid crystal layer. A liquid crystal cylindrical lens array that overlaps a region where the second electrode exists. The equal to the width of the second electrode, or in a range smaller than the width of the second electrode, the liquid crystal cylindrical lens array, wherein the resistance value of the high resistance layer has a large value. 2. The liquid crystal cylindrical lens array according to claim 1, wherein the transparent lens is arranged in a range that overlaps a region where the second electrode exists and is equal to a width of the second electrode or narrower than a width of the second electrode. A liquid crystal cylindrical lens array, wherein a high resistance layer is removed. 3. The liquid crystal cylindrical lens array according to claim 1, wherein a plurality of second electrodes are separated through slits, and different voltages are applied to the separated electrodes. A liquid crystal cylindrical lens array characterized by that. A display panel having the liquid crystal cylindrical lens array according to any one of claims 1 to 3 disposed thereon and a position sensor, wherein a voltage applied to the liquid crystal cylindrical lens array is controlled by a signal related to a position by the position sensor for display. A display device that adjusts the characteristics of a panel. 5. A display device according to claim 4, wherein the display panel is any one of a liquid crystal display panel, an organic EL display panel, a plasma display panel, and an electroluminescence display panel.