KR20130053652A - Dynamic thin flat type light-beam deflector - Google Patents

Abstract

PURPOSE: An active thin film flat type light deflection device is provided to deflect a focus point of a stereo-scopic image in a stereoscopic image displayer by a thin film type autostereoscopic hologram method according to a movement of a viewer. CONSTITUTION: A thin film flat type light deflection device comprises a lower substrate(LS); a first lower electrode layer(LEL1) formed in an inner side of the lower substrate; a second lower electrode layer(LEL2) formed on the first lower electrode layer; an upper substrate(US) which attached facing to the lower substrate; a first upper electrode layer formed in the inner side of the upper plate and facing the first lower electrode layer; a second upper electrode layer formed on the first upper electrode layer and facing the second lower electrode layer; and a liquid crystal layer interposed between the second lower electrode layer and the second upper electrode layer.

Description

Active Thin Flat Type Light-Beam Deflector

The present invention relates to an active thin film flat optical deflector. In particular, the present invention relates to an active thin film flat light deflector for eye tracking for focusing the viewer's field of view as the viewer moves in a three-dimensional imaging device for reconstructing / reproducing a digital hologram image.

Recently, three dimensional (3D) image and image reproduction techniques have been actively studied. 3D image related media is expected to lead the next generation imaging device as a realistic image media with a new concept that raises the level of visual information one more level. The conventional 2D image system provides the plane image, but the 3D image system is the ultimate image realization technology in terms of showing the actual image information of the object to the observer.

As a method for reproducing 3D stereoscopic images, methods such as stereoscopy, auto-stereoscopy, volumetric, holography, and integrated imaging are widely used. Research and development. Among these, the holography method is a method that can sense a three-dimensional feeling most similar to the real thing without attaching special glasses when observing the holography produced using a laser. Accordingly, the holography method is excellent in three-dimensionality and is characterized by being able to feel a three-dimensional effect even with a monocular, and is known as the most ideal way for an observer to feel a three-dimensional image without fatigue.

The holographic method uses the principle of recording and reproducing an interference signal obtained by superimposing light (object wave) reflected from an object and light (reference wave) having coherence. An interference fringe formed by colliding an object wave scattered by an object with a reference wave incident in another direction using a highly coherent laser light is recorded on the scattering film. When an object wave and a reference wave meet, an interference fringe due to interference is formed. The amplitude and phase information of the object are also recorded in this fringe pattern. By irradiating reference light to the interference fringes recorded in this manner, the interference information recorded in the hologram is restored, and the three-dimensional stereoscopic effect is felt. A series of processes for creating three-dimensional images using these recording and reconstruction principles is called holography.

A computer generated hologram (CGH) has been developed as a method for computer generated holograms for storage, transmission and image processing. This computer-generated hologram has been developed in various ways so far. Recently, a system for displaying a computer-generated hologram of a moving image without developing a computer-generated hologram of a still image has been developed due to the development of the digital industry.

A computer generated hologram is an interference pattern that is stored directly in a hologram using a computer. The interference fringe image is generated by a computer and then transmitted to a spatial light modulator such as a liquid crystal-spatial light modulator (LC-SLM), and the reference light is irradiated to the SLM to restore / Playback. 1 is a block diagram of a digital hologram image reproducing apparatus embodying a computer generated hologram method according to the related art.

Referring to FIG. 1, an interference fringe image corresponding to a stereoscopic image to be implemented in the computer 10 is generated. The generated interference fringes are transmitted to the SLM 20. The SLM 20 may be formed of a transmissive liquid crystal display panel to display an interference pattern. On one side of the SLM 20, a laser light source 30 to be used as a reference light is located. The expander 40 and the lens 50 are sequentially arranged in order to uniformly project the reference light 90 irradiated from the laser light source 30 to the front surface of the SLM 20. [ The reference light 90 emitted from the laser light source 30 is irradiated to one side of the SLM 20 through the expander 40 and the lens 50. [ When the SLM 20 is a transmissive liquid crystal display panel, a three-dimensional stereoscopic image 80 is displayed on the other side of the SLM 20 by the interference pattern of the hologram implemented in the SLM 20. [

The 3D imaging apparatus using the hologram method of FIG. 1 is a stereoscopic image display apparatus of a non-glasses type. In the case of the autostereoscopic display device, the stereoscopic image must be focused within the viewer's field of view so that the correct stereoscopic image can be enjoyed. In particular, the 3D stereoscopic image by the hologram method is formed in the position that the viewer can observe in the space between the display device and the viewer. Therefore, when the viewer moves the position, it is necessary to adjust the focal position of the hologram image to move in parallel along the viewing focus of the viewer.

Various types of optical deflectors have been proposed. Representatively, an optical deflector by a holography method and an optical deflector by a phase mask method have been proposed. However, since these optical deflectors have only a fixed deflection angle, they do not actively deflect light depending on the moving position of the viewer.

Meanwhile, an optical polarizer using a difference in refractive index of liquid crystals has been proposed. For example, there are US patents US 3,843,231 and US 4,850,682. They can adjust the range of deflection angles to some extent, but the deflection angle range is extremely limited due to structural limitations. In particular, when a viewer moves a considerable distance from left to right in a large display device such as a TV, it does not deflect light in a large angle range. However, US 3,843,231 does not actively deflect light since it has only a fixed deflection angle. Moreover, in the case of US 4,850,682 there are also manufacturing process and cost problems that require precise machining of the surface of the substrate.

Accordingly, in order to provide a correct stereoscopic image in an autostereoscopic 3D image display device, an optical deflector that tracks a change of a viewer's position and deflects a focal position of the image in a parallel direction is required. In particular, there is a need for an active and thin film type optical deflector that can be effectively applied to a thin film type stereoscopic imaging device.

An object of the present invention is to solve the above problems, and to provide an active optical deflection device that deflects the focal position of the stereoscopic image in accordance with the movement of the viewer in the autostereoscopic stereoscopic imaging apparatus. Another object of the present invention is to provide an active thin film flat type optical deflection device which deflects a focal position of a stereoscopic image according to a viewer's movement in a stereoscopic image device using a thin film autostereoscopic hologram method.

In order to achieve the object of the present invention, the active thin film flat-type optical deflection apparatus according to the present invention, the lower substrate; A first lower electrode layer formed on an inner side surface of the lower substrate; A second lower electrode layer formed on the first lower electrode layer; An upper substrate attached to face the lower substrate; A first upper electrode layer formed on an inner side of the upper substrate and facing the first lower electrode layer; A second upper electrode layer formed on the first upper electrode layer and facing the second lower electrode layer; And a liquid crystal layer interposed between the second lower electrode layer and the second upper electrode layer.

The first lower electrode layer includes a plurality of first lower electrodes having a constant electrode width and spaced apart by an interval width of the same size as the electrode width; The second lower electrode layer is characterized in that it comprises a plurality of second lower electrodes having the same width as the electrode width and arranged to overlap between the first lower electrodes.

Applying a voltage that is changed in at least one of sequential incremental change and sequential incremental change to n lower electrodes sequentially arranged among the first lower electrodes and the second lower electrodes; Applying a common voltage to the first upper electrode layer and the second upper electrode layer; The apparatus may further include a voltage driver configured to gradually change the refractive index of the liquid crystal layer, thereby setting the liquid crystal layer to an ON driving state.

The voltage driver may be configured to variably adjust a difference between the minimum voltage and the maximum voltage in the sequential increase change and sequential increase and decrease change methods in the ON driving state.

The voltage driver applies a common voltage to the first lower electrode layer and the first upper electrode layer; The second lower electrode layer and the second upper electrode layer may be set to an OFF driving state by applying a maximum voltage to change the refractive index of the liquid crystal layer to the same state.

The first upper electrode layer includes a plurality of first upper electrodes having a constant electrode width and arranged apart with an interval width of the same size as the electrode width; The second upper electrode layer is characterized in that it comprises a plurality of second upper electrodes having the same width as the electrode width and arranged to overlap between the first upper electrodes.

Applying a voltage that is changed in at least one of sequential incremental change and sequential incremental change to n upper electrodes sequentially arranged among the first upper electrodes and the second upper electrodes; Applying a common voltage to the first lower electrode layer and the second lower electrode layer; The apparatus may further include a voltage driver configured to gradually change the refractive index of the liquid crystal layer, thereby setting the liquid crystal layer to an ON driving state.

The voltage driver may be configured to variably adjust a difference between the minimum voltage and the maximum voltage in the sequential increase change and sequential increase and decrease change methods in the ON driving state.

The voltage driver applies a common voltage to the first lower electrode layer and the first upper electrode layer; The second lower electrode layer and the second upper electrode layer may be set to an OFF driving state by applying a maximum voltage to change the refractive index of the liquid crystal layer to the same state.

A first lower insulating layer covering the first lower electrode layer and having the second lower electrode layer formed thereon; A second lower insulating layer covering the second lower electrode layer; A first upper insulating layer covering the first upper electrode layer and having the second upper electrode layer formed thereon; And a second upper insulating film covering the second upper electrode layer.

The optical deflector according to the present invention forms a prism for optical deflection having an optional inclined plane angle by using a liquid crystal layer driven in ECB mode. Therefore, by adjusting the voltage applied to the liquid crystal layer, it is possible to actively adjust the inclined plane angle of the light deflection prism, which means the change in the refractive index of the liquid crystal layer for light deflection. That is, the optical deflector according to the present invention may selectively deflect light of an actively incident stereoscopic image in a desired direction. In addition, the optical deflector according to the present invention is implemented as a thin film flat panel including a liquid crystal layer driven in the ECB mode. Therefore, the optical deflector according to the present invention is a device suitable for implementing a thin film holographic stereoscopic imaging device.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a configuration of a digital hologram image reproducing apparatus embodying a computer generated hologram system according to the prior art; Fig.
2 is a cross-sectional view showing the structure of an active thin film flat optical deflector according to the present invention;
3A is a cross-sectional view showing an optical path passing through the optical deflector in a state in which no electric field is applied to the optical deflector.
3B is a cross-sectional view showing an optical path passing through the optical deflector in a state where an electric field is applied to the optical deflector.
4A is a cross-sectional view showing a voltage application structure in which six neighboring electrodes make an ON state by a vertical electric field in an optical deflector forming a unit prism;
FIG. 4B is a cross-sectional view illustrating a voltage application structure in which a horizontal electric field is applied in an ON state by a vertical electric field and changed to an OFF state as shown in FIG. 4A; FIG.
5 is a schematic diagram showing the structure of a digital holographic image reproducing apparatus using a transmissive liquid crystal display;
FIG. 6 is a perspective view illustrating a state in which a light of a stereoscopic image is deflected according to a position change of a viewer in a holographic stereoscopic image display device having an eye-tracker (ET) using an optical deflector according to the present invention; FIG.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings, FIGS. 2 to 6. Like reference numerals throughout the specification denote substantially identical components. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description, a detailed description of known technologies or configurations related to the present invention will be omitted when it is determined that the gist of the present invention may be unnecessarily obscured.

2 is a cross-sectional view showing the structure of an active thin film flat optical deflector according to the present invention. 2, the optical deflector according to the present invention includes the liquid crystal layer EC interposed between the lower substrate LS and the upper substrate US.

The lower electrode layer for driving the liquid crystal layer EC is formed on an inner surface of the lower substrate LS. In particular, the lower electrode layer is formed to have a two-layer structure in order to minimize the distance between the electrodes to be densely arranged. For example, the first lower electrode layer LEL1 may be formed on the first layer of the inner surface of the lower substrate LS, and the second lower electrode layer LEL2 may be formed on the second layer.

The transparent conductive material is coated and patterned on the lower substrate LS, so that the electrodes of the first lower electrode layer LEL1 have a predetermined line width and are arranged at regular intervals. As a method of forming the electrode of the first lower electrode layer LEL1, a laser method (LASER Direct Writing), photolithography or a printing technique is used. At this time, in order to form a fine pattern when forming a wire-shaped electrode, an electrode width and an electrode interval are determined to have a maximum resolution for wiring formation. That is, the first lower electrode layer LEL1 is necessarily formed to be spaced apart at a predetermined interval. In particular, the minimum value of the electrode interval, which is the distance at which the electrodes are spaced apart, is preferably about the same as the value of the electrode width.

The entire surface of the lower substrate LS on which the first lower electrode layer LEL1 is formed is coated with the first lower insulating layer LIN1. In particular, when the organic insulating material is used, the upper surface of the first lower insulating layer LIN1 may be kept flat. A transparent conductive material is coated and patterned on the first lower insulating layer LIN1 to form electrodes of the second lower electrode layer LEL2. Electrodes of the second lower electrode layer LEL2 may be disposed to overlap empty spaces between the electrodes of the first lower electrode layer LEL1. Like the electrodes of the first lower electrode layer LEL1, the electrodes of the second lower electrode layer LEL2 are preferably arranged at the same electrode interval as the electrode width.

The second lower insulating layer LIN2 is applied to the entire surface of the lower substrate LS on which the second lower electrode layer LEL2 is formed to protect the same. In particular, when the organic insulating material is used, the upper surface of the second lower insulating layer LIN2 may be kept flat. As a result, as shown in FIG. 2, the electrodes of the first lower electrode layer LEL1 and the electrodes of the second lower electrode layer LEL2 are alternately stacked.

Similarly, the first upper electrode layer UEL1 is formed on the first layer and the second upper electrode layer UEL2 is formed on the second layer on the inner surface of the upper substrate US. That is, the electrodes of the first upper electrode layer UEL1 are formed of a transparent conductive material on the upper substrate US. The electrodes of the first upper electrode layer UEL1 preferably have a constant electrode width and are arranged at the same electrode interval as the electrode width. The first upper electrode layer UEL1 is coated with the first upper insulating layer UIN1. Similarly, it is preferable to keep the surface of the first upper insulating film UIN1 flat by using an organic insulating material.

The second upper electrode layer UEL2 is formed of a transparent conductive material on the first upper insulating layer UIN1. Electrodes of the second upper electrode layer UEL2 may be disposed to overlap empty spaces between the electrodes of the first upper electrode layer UEL1. Like the electrodes of the first upper electrode layer UEL1, the electrodes of the second upper electrode layer UEL2 are preferably arranged at the same electrode interval as the electrode width.

The second upper insulating layer UIN2 is applied to the entire surface of the upper substrate US on which the second upper electrode layer UEL2 is formed to protect the same. In particular, when the organic insulating material is used, the upper surface of the second upper insulating layer UIN2 may be kept flat. As a result, as shown in FIG. 2, the electrodes of the first upper electrode layer UEL1 and the electrodes of the second upper electrode layer UEL2 are alternately stacked.

Thus, the upper substrate US and the lower substrate LS on which the electrode layers are formed are bonded to face each other with the liquid crystal layer EC therebetween, thereby completing an active thin film flat type optical deflecting device.

Hereinafter, the optical deflecting device according to the present invention will be described with reference to FIGS. 3A to 3B. 3A is a cross-sectional view illustrating an optical path passing through the optical deflecting apparatus without an electric field applied to the optical deflecting apparatus. 3B is a cross-sectional view illustrating an optical path passing through the optical deflecting apparatus while an electric field is applied to the optical deflecting apparatus. Here, a case of forming a unit prism with three neighboring electrodes among the lower and upper electrodes facing each other will be described. For example, as shown in FIGS. 3A and 3B, two first lower electrode layers LEL1 and one second lower electrode layer LEL2 disposed therebetween may be determined as a unit prism length.

First, in a state in which no electric field is applied between the upper and lower electrodes facing each other, as shown in FIG. 3A, the liquid crystals of the ECB mode constituting the liquid crystal layer LC are arranged in a horizontal direction in an initial arrangement state. Since all of the liquid crystal layers EC are arranged in a horizontal state, there is no change in the refractive index of the liquid crystal layer EC. That is, the light 800 incident from the rear surface of the lower substrate LS passes through the liquid crystal layer EC as it is and proceeds to the outgoing light 900 which is not refracted.

On the other hand, the situation is different when an electric field is applied between the upper and lower electrodes. Three neighboring electrodes among the electrodes arranged on the lower substrate LS are referred to as the lower first electrode 101, the lower second electrode 102, and the lower third electrode 103, and face the upper substrate US. The electrodes arranged in FIG. 2 are referred to as an upper first electrode 201, an upper second electrode 202, and an upper third electrode 203, respectively. In this case, little voltage is applied between the lower first electrode 101 and the upper first electrode 201, and a medium voltage is applied between the lower second electrode 102 and the upper second electrode 202. In addition, a maximum voltage may be applied between the lower third electrode 103 and the upper third electrode 203. Then, as illustrated in FIG. 3B, a difference in refractive index occurs in the liquid crystal layer EC as if a prism having a shape like a right triangle is formed. In this state, the light 800 incident from the rear surface of the lower substrate LS proceeds to the refracted output light 901 refracted by an angle equal to the oblique plane inclination angle α of the prism.

In addition, by adjusting the voltage applied to each of the lower electrode and the upper electrode, the oblique inclination angle of the formed prism can be adjusted. The maximum magnitude of the deflection angle at which incident light is refracted by the liquid crystal layer EC may be determined by a length of a unit prism and a cell gap of the liquid crystal layer EC, as shown in Equation 1. Alternatively, as in Equation 2, the length of the unit prism and the wavelength of the incident light may be determined.

Referring to Equations 1 and 2, it can be seen that the deflection maximum angle α is inversely proportional to the length of the unit prism. Therefore, if the deflection angle is to be increased, the length of the unit prism must be reduced. In the optical deflecting device according to the present invention, the array of electrodes constituting the prism is configured in a two-layer structure, and has a compact structure in which no empty space exists between neighboring electrodes. Therefore, the deflection angle can be formed as large as desired. For example, in addition to deflection at an angle smaller than 45 degrees, it is also possible to deflect incident light at an angle as large as 70 degrees.

Hereinafter, a detailed method of applying a voltage to the upper electrode and the lower electrode for forming the refractive index difference will be described in more detail with reference to FIGS. 4A to 4B. In this description, for convenience, a case in which a unit prism is formed of six neighboring electrodes among lower and upper electrodes facing each other will be described.

4A is a cross-sectional view showing a voltage application structure in which six neighboring electrodes make an ON state by a vertical electric field in an optical deflector forming a unit prism. 4B is a cross-sectional view illustrating a voltage application structure in which a horizontal electric field is applied to the OFF state by turning on a vertical electric field as shown in FIG. 4A. Although not shown, it is preferable to further include a voltage driver for voltage application.

Referring to FIG. 4A, six neighboring lower electrodes, a lower first electrode 101, a lower second electrode 102, a lower third electrode 103, a lower fourth electrode 104, and a lower fifth electrode ( 105) and a voltage of V1, V2, V3, V4, V5, and V6 is applied to each of the lower sixth electrodes 106. At this time, V1 to V6 may have a voltage to increase or decrease the difference sequentially. For example, voltages of 1V, 2V, 3V, 4V, 5V and 6V may be applied. And six opposing upper electrodes, the upper first electrode 201, the upper second electrode 202, the upper third electrode 203, the upper fourth electrode 204, the upper fifth electrode 205, and the upper agent. The six electrodes 206 are all applied with a common voltage of 0V. Then, as illustrated in FIG. 4A, a difference in refractive index occurs in the liquid crystal layer EC as if a prism having a shape like a right triangle is formed. In this state, the light 800 incident on the rear surface of the lower substrate LS proceeds to the refracted output light 901 refracted by an angle equal to the oblique plane inclination angle β of the prism.

Referring to FIG. 4A, a case in which the liquid crystal layer EC is turned on in the prism mode by applying a voltage that sequentially increases or decreases to neighboring lower electrodes and a common voltage is applied to the upper electrodes is described. It was. However, the voltage driver may be operated to apply a common voltage to the lower electrodes and to sequentially increase or decrease the voltage to the upper electrodes.

The easiest way to think of in order to make the OFF state from the ON state as shown in FIG. 4A is to apply a common voltage of 0V to all of the neighboring lower electrodes. However, due to the characteristics of the ECB liquid crystal, the reaction rate when the voltage is applied to the electromagnetic field OFF state is much slower than the reaction speed when the voltage is applied to the ON state when the voltage is applied. Therefore, when the eye tracking is implemented by the method of turning off the radio field, it may cause a problem that the moving viewer cannot be tracked quickly.

As a method for solving this problem, as shown in Fig. 4B, when making the OFF state, it is conceivable to apply the horizontal electric field to make the OFF state. For example, among the six neighboring lower electrodes, a common voltage of 0 V is applied to the lower first electrode 101, the lower third electrode 103, and the lower fifth electrode 105 corresponding to the first lower electrode layer. do. On the other hand, a maximum voltage, for example, a 6V voltage, is applied to the lower second electrode 102, the lower fourth electrode 104, and the lower sixth electrode 106 corresponding to the second lower electrode layer. Then, a horizontal electric field is applied between the lower electrodes.

At the same time, a horizontal electric field can be applied to the upper electrodes in the same manner. That is, among the six upper electrodes, a common voltage of 0 V is applied to the upper first electrode 201, the upper third electrode 203, and the upper fifth electrode 205 corresponding to the first upper electrode layer. On the other hand, a maximum voltage, for example, a 6V voltage, is applied to the upper second electrode 202, the upper fourth electrode 204, and the upper sixth electrode 206 corresponding to the second upper electrode layer. Then, a horizontal electric field is applied between the upper electrodes.

As a result, the liquid crystal layer EC is rearranged in a horizontal state by the horizontal electric field formed in the lower electrode layer and the upper electrode layer. That is, it has the same state as the OFF state by the initial electromagnetic field. However, the signal is turned off by the horizontal electric field rather than by the OFF state. As such, when the horizontal electric field is applied to the OFF state, the ECB liquid crystals react quickly, and thus the light deflection change can be quickly performed.

The optical deflecting device according to the present invention can be applied to an autostereoscopic 3D display device to implement an eye tracker that tracks the viewer when the viewer changes the viewing position in the horizontal direction in front of the display device. Hereinafter, a case in which an optical deflecting device for eye tracking is applied to a holographic stereoscopic image display using a transmissive liquid crystal display will be described with reference to the drawings. 5 is a schematic diagram showing the structure of a digital holographic image reproducing apparatus using a transmissive liquid crystal display.

Referring to FIG. 5, the SLM 200 is configured as a transmissive liquid crystal display panel. That is, the SLM 200 is formed of a transmissive liquid crystal display panel in which the upper plate SU formed of a transparent glass substrate and the lower plate SD face each other, and are coupled through the liquid crystal layer LC therebetween. The SLM 200 receives interference fringe pattern data from a computer or a video processing device (not shown), and displays the interference fringe. Each of the upper plate SU and the lower plate SD may include a thin film transistor and a color filter constituting the liquid crystal display panel.

The backlight unit BLU including the light source 300 and the optical fiber OF is disposed on the lower surface of the SLM 200. The light source 300 may be configured as a light source 300 using laser diodes including red laser diodes (R), green laser diodes (G), and blue laser diodes (B) or red, green, and blue collimated LEDs. have. Meanwhile, the light source 300 may be a light source 300 that combines R, G, B, or other colors that distinguish red, green, and blue, and may be a single light source such as a white laser diode or a white collimated LED. 300). As described above, the light source 300 may be various. For convenience, the light sources 300 will be described in the case of the red, green, and blue laser diodes R, G, and B.

The optical fiber OF is used to evenly guide the reference light emitted from the light source 300 to the lower front surface of the SLM 200 substrate. For example, laser diodes R, G, and B may be disposed on one side of the backlight unit BLU. In addition, the laser light emitted from the laser diodes R, G, and B may be extended from the lower surface of the SLM 200 by using the optical fiber OF. The optical fiber OF may be disposed to correspond to the front surface of the SLM 200 which is a liquid crystal panel. In particular, a plurality of light output parts OUT are formed to remove a part of the clad surrounding the core of the optical fiber OF to emit laser light to the outside of the optical fiber OF so that the laser light is irradiated to the entire liquid crystal panel. Can be. In addition, between the SLM 200 and the optical fiber OF, an optical sheet 500 for adjusting the reference light extended by the optical fiber OF to maintain the size corresponding to the area of the SLM 200 and to run in parallel straight. It may further include.

Then, the front of the SLM 200 detects the position of the spectator, calculates the viewing angle according to the position of the viewer, and the eye-tracker (ET) for deflecting the stereoscopic image according to the viewing angle of the viewer is disposed. .

FIG. 6 is a perspective view illustrating a state in which a light of a stereoscopic image is deflected according to a position change of a viewer in a holographic stereoscopic image display device having an eye-tracker (ET) using an optical deflector according to the present invention. Referring to FIG. 6, when the viewer is in the center position of the holographic stereoscopic image display device, the optical deflector constituting the eye tracker ET may be in an OFF state by an electromagnetic field or an OFF state by a horizontal electric field. Has On the other hand, when the viewer is in the left position (Left Position) in the center of the holographic stereoscopic display device, the viewer has an ON state by the optical deflector vertical electric field constituting the eye tracker ET. When the viewer is in the right position at the center of the holographic stereoscopic image display device, the viewer has the ON state by the vertical electric field having the same size but the opposite size as the case on the left side.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

10: computer 20, 200: spatial light modulator (SLM)
30, 300: laser light source 40: expander
50: Lens 80: Output image
90: reference light 500: optical sheet
SU: top plate SD: bottom plate
LC: liquid crystal layer R: red laser diode
G: green laser diode B: blue laser diode
OF: fiber optic BLU: backlight unit
OUT: light exit part IN: light exit part
LS: lower substrate US: upper substrate
LEL1: first lower electrode layer LEL2: second lower electrode layer
LIN1: first lower insulating layer LIN2: second lower insulating layer
UEL1: first upper electrode layer UEL2: second upper electrode layer
UIN1: first upper insulating layer UIN2: second upper insulating layer
800: incident light 900: unrefractive light
901: refractive exit light EC: (ECB) liquid crystal layer

Claims (10)

A lower substrate;
A first lower electrode layer formed on an inner side surface of the lower substrate;
A second lower electrode layer formed on the first lower electrode layer;
An upper substrate attached to face the lower substrate;
A first upper electrode layer formed on an inner side of the upper substrate and facing the first lower electrode layer;
A second upper electrode layer formed on the first upper electrode layer and facing the second lower electrode layer; And
And a liquid crystal layer interposed between the second lower electrode layer and the second upper electrode layer.
The method of claim 1,
The first lower electrode layer includes a plurality of first lower electrodes having a constant electrode width and spaced apart by an interval width of the same size as the electrode width;
The second lower electrode layer includes a plurality of second lower electrodes having a width equal to the electrode width and arranged to overlap between the first lower electrodes.
3. The method of claim 2,
Applying a voltage that is changed in at least one of sequential incremental change and sequential incremental change to n lower electrodes sequentially arranged among the first lower electrodes and the second lower electrodes;
Applying a common voltage to the first upper electrode layer and the second upper electrode layer;
And a voltage driver for setting the liquid crystal layer to an ON driving state by causing the refractive index of the liquid crystal layer to change gradually.
The method of claim 3, wherein the voltage driver is set to an ON driving state.
Thin film flat-type optical deflector, characterized in that for controlling the difference between the minimum voltage and the maximum voltage in the sequential increase change and sequential increase and decrease change.
The method of claim 3, wherein the voltage driver
Applying a common voltage to the first lower electrode layer and the first upper electrode layer;
And applying a maximum voltage to the second lower electrode layer and the second upper electrode layer so as to change the refractive index of the liquid crystal layer to the same state, thereby setting it to an OFF driving state.
The method of claim 1,
The first upper electrode layer includes a plurality of first upper electrodes having a constant electrode width and arranged apart with an interval width of the same size as the electrode width;
And the second upper electrode layer comprises a plurality of second upper electrodes arranged to overlap between the first upper electrodes and having the same width as the electrode width.
The method according to claim 6,
Applying a voltage that is changed in at least one of sequential incremental change and sequential incremental change to n upper electrodes sequentially arranged among the first upper electrodes and the second upper electrodes;
Applying a common voltage to the first lower electrode layer and the second lower electrode layer;
And a voltage driver for setting the liquid crystal layer to an ON driving state by causing the refractive index of the liquid crystal layer to change gradually.
The method of claim 7, wherein the voltage driver is set to an ON driving state.
Thin film flat-type optical deflector, characterized in that for controlling the difference between the minimum voltage and the maximum voltage in the sequential increase change and sequential increase and decrease change.
The method of claim 8, wherein the voltage driver
Applying a common voltage to the first lower electrode layer and the first upper electrode layer;
And applying a maximum voltage to the second lower electrode layer and the second upper electrode layer so as to change the refractive index of the liquid crystal layer to the same state, thereby setting it to an OFF driving state.
The method of claim 1,
A first lower insulating layer covering the first lower electrode layer and having the second lower electrode layer formed thereon;
A second lower insulating layer covering the second lower electrode layer;
A first upper insulating layer covering the first upper electrode layer and having the second upper electrode layer formed thereon; And
And a second upper insulating film covering the second upper electrode layer.

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