KR100786860B1 - Autostereoscopic display appratus having varifocal lens - Google Patents

Abstract

The present invention relates to a stereoscopic image display apparatus that realizes a more natural three-dimensional stereoscopic image by providing a difference in depth of each pixel by changing a focal length of a lens corresponding to each pixel.

The stereoscopic image display device includes a flat panel display for time-divisionally driving left and right eye images; It is disposed on the front of the flat display at a predetermined distance from the flat display, and includes a plurality of variable focus lenses combining a vertical lenticular lens and a horizontal lenticular lens in which a liquid crystal layer and electrodes are built, and correspondingly corresponding to each pixel. A variable focus lens unit for changing a focal length of the focus lens; It is disposed in front of the variable focus lens unit, and includes a liquid crystal prism that separates the left and right eye images in the left and right eye directions, respectively, in synchronization with the flat panel display.

Stereoscopic image, variable focus, flat panel display, lenticular lens, liquid crystal, focal length, prism, fresnel lens

Description

Stereoscopic image display device with variable focus lens {AUTOSTEREOSCOPIC DISPLAY APPRATUS HAVING VARIFOCAL LENS}

1 is a perspective view of a stereoscopic image display apparatus according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the stereoscopic image display device shown in FIG. 1. FIG.

3 is a partially exploded perspective view of a variable focus lens unit;

4 is a schematic diagram for explaining a process of changing a focal length by a variable focus lens;

5 is a partially exploded perspective view of a liquid crystal prism.

6 is a partially enlarged cross-sectional view of a Fresnel lens.

7 is a schematic diagram for explaining the phenomenon of inconsistency between monocular adjustment and convergence angle.

The present invention relates to a stereoscopic image display apparatus, and more particularly, to a stereoscopic image display apparatus which varies a focal length of a lens corresponding to each pixel to give a difference in depth of each pixel.

In general, a stereoscopic image display device is a device that allows viewers to see different images with the left and right eyes so that the viewer can feel a sense of distance and a three-dimensional feeling in the image viewed by the viewer. Auto-stereoscopy devices that divide the viewer's left and right eyes are well known.

However, the conventional auto-stereoscopic device realizes an unnatural 3D image due to a mismatch between monocular accomodation and convergence angle, and eyes are easily tired when watching the 3D image for a long time. Is holding.

Fig. 7 is a schematic diagram for explaining the mismatch between monocular adjustment and convergence angle, where a light source forming an image at a glance exists on the flat panel display 1 such that the left and right eyes of the viewer are located there. Although it feels (two monocular adjustments, A1, A2), the sense of distance from the stereopsis of the two eyes is where the two lines meet (convergence angle, B), so the three points are inconsistent.

Therefore, the electro-hologram method and the volumetric method have been devised to solve the unnaturalness of the stereoscopic image described above. However, current methods have difficulty in implementing these methods.

That is, the electronic hologram method has to provide each pixel with an interference pattern of all the light passing through each pixel from the three-dimensional object, as compared to a two-dimensional display device that provides only the information about the light intensity to each pixel to implement an image. As a result, current systems are unable to process large amounts of data, and thus are unlikely to be implemented.

In addition, when the volumetric method rotates a two-dimensional screen, there is a mechanical problem due to the screen rotation, there is a limitation that a method of scanning a three-dimensional space at high speed should be prepared.

As a result, both the above-described electronic hologram method and the volumetric method have a lot of difficulties in solving the unnatural stereoscopic image of the aforementioned auto-stereoscopy device in a short time.

Accordingly, an object of the present invention is to solve the above problems, and an object of the present invention is to adopt a simpler configuration than an electro-hologram method and a volumetric method, and to implement a three-dimensional image that is more natural than a conventional auto-stereoscopic device. It is to provide a display device.

In order to achieve the above object, the present invention,

A plurality of flat panel displays that time-divisionally drive left and right images, and are disposed in front of the flat display at predetermined intervals from the flat display, and each of which combines a vertical lenticular lens and a horizontal lenticular lens with a liquid crystal layer and electrodes embedded therein. A variable focus lens unit having a variable focus lens to change the focal length of the variable focus lens corresponding to each pixel, and disposed in front of the variable focus lens unit, and left and right eye images are respectively synchronized with the flat panel display. The present invention provides a stereoscopic image display device including a liquid crystal prism separating in the right eye direction.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.                     

1 is a perspective view of a stereoscopic image display apparatus according to an embodiment of the present invention, Figure 2 is an exploded perspective view of the stereoscopic image display apparatus shown in FIG.

As shown, the stereoscopic image display apparatus 2 combines a flat display 10 for time-divisionally driving left and right eye images, a vertical lenticular lens plate and a horizontal lenticular lens plate in which respective liquid crystal layers and electrodes are incorporated. A variable focus lens unit 20 including a plurality of variable focus lenses to change a focal length of a lens corresponding to each pixel, and a liquid crystal prism 40 and a Fresnel lens disposed after the variable focus lens unit 20 And 50.

The flat panel display 10 is preferably a projection display or a liquid crystal display that emits light substantially perpendicularly from the display screen, and particularly preferably a liquid crystal display having a polarizing plate to emit light in a specific polarization direction.

This is because the variable focus lens unit 20 disposed after the flat panel display 10 changes the focal length of the lens corresponding to each pixel according to the arrangement of liquid crystals, and thus the polarization direction of the image emitted by the flat panel display 10 This is because the focal length can be easily changed only when the angle formed by the arrangement of the liquid crystals is constant.

The flat panel display 10 receives the left and right eye signals and time-divisions the left and right eye images, and the variable focus lens unit 20 is disposed on the front of the flat display 10 at regular intervals from the flat display 10. Is placed.

3 is a partially exploded perspective view of the variable focus lens unit, and FIG. 4 is a schematic diagram for describing a process of changing a focal length by the variable focus lens.                     

The variable focus lens unit 20 includes a vertical lenticular lens plate 21 having a first liquid crystal layer 27 and a vertical lenticular lens 23, a second liquid crystal layer 30 and a horizontal lenticular lens ( The horizontal lenticular lens plate 22 having 24 is vertically intersected, and the intersection points of the vertical and horizontal lenticular lenses 23 and 24 are arranged to correspond to the respective pixels of the flat panel display 10. The point functions as the variable focus lens 25 described above.

More specifically, the vertical lenticular lens plate 21 has a transparent first and second substrates 26a and 26b disposed to face each other at arbitrary intervals, and a shortened direction of the screen on an inner surface of the first and second substrates 26a and 26b opposite to the first substrate 26a. An encapsulated material between the vertical lenticular lens 23 having a plurality of semi-circular recesses 23a arranged along the Y axis of the drawing, and between the first substrate 26a and the vertical lenticular lens 23. One liquid crystal layer 27 is included. At this time, the width W1 of the semi-circular concave portion 23a along the long axis direction of the screen (the X axis of the drawing) is equal to the width of the pixel along the long axis direction of the screen (the X axis of the drawing).

On the inner surface of the first substrate 26a, a plurality of first electrodes 28a are formed in a stripe pattern along the short axis direction of the screen (the Y axis of the drawing), and the long axis direction of the screen is formed on the inner surface of the second substrate 26b. A plurality of second electrodes 28b are formed in a stripe pattern along the (X-axis in the figure) to vertically intersect the first electrodes 28a.

In the first liquid crystal layer 27, when no voltage is applied (see the right portion indicated as OFF in the drawing), the long axes of the liquid crystal molecules are uniformly arranged along the short axis direction of the screen (Y axis in the drawing), and the first liquid crystal layer When an electric field is formed in the layer 27 (see the left portion indicated as ON in the figure), the long axis of each liquid crystal molecule is rotated at an angle from the short axis of the screen (the Y axis in the figure) to change the arrangement of the liquid crystals. do.

The horizontal lenticular lens plate 22 is a configuration in which the vertical lenticular lens plate 21 is rotated at an angle of 90 °, and more specifically, the horizontal lenticular lens plate 22 is disposed to face each other at an arbitrary interval. Horizontal with third and fourth substrates 29a and 29b and a plurality of semi-circular recesses 24a arranged along the major axis direction of the screen (X axis in the drawing) on the inner surface facing the third substrate 29a. A semi-circle along the axial direction of the screen (Y-axis in the drawing), including a lenticular lens 24 and a second liquid crystal layer 30 enclosed between the third substrate 29a and the horizontal lenticular lens 24. The width W2 of the mold recess 24a is equal to the width of the pixel along the short axis direction of the screen (Y axis in the drawing).

In addition, a plurality of third electrodes 31a are formed on the inner surface of the third substrate 29a in a stripe pattern along the long axis direction of the screen (the X axis of the drawing), and a short axis direction of the screen is formed on the inner surface of the fourth substrate 29b. A plurality of fourth electrodes 31b are formed in a stripe pattern along the (Y-axis in the drawing) to vertically intersect with the third electrodes 31a.

When the second liquid crystal layer 30 also has no voltage applied (see the upper portion indicated as OFF in the drawing), the long axes of the liquid crystal molecules are constantly arranged along the long axis direction of the screen (X axis in the drawing), and the second liquid crystal layer When an electric field is formed in the layer 30 (see the lower part indicated as ON in the figure), the major axis of each liquid crystal molecule is rotated at an angle from the major axis of the screen (the X axis of the figure), thereby changing the arrangement state of the liquid crystal. .

According to the above configuration, taking any one variable focusing lens 25 as an example, the first and second electrodes 28a and 28b and the third and fourth electrodes 31a and 31b corresponding to the variable focusing lens 25 are used. If no electric field is applied to the first and second liquid crystal layers 27 and 30 because no voltage is applied, the variable focus lens 25 is an optical combination of the vertical lenticular lens 23 and the horizontal lenticular lens 24. Have a fixed focal length.

On the other hand, when an electric field is formed in the first and second liquid crystal layers 27 and 30 by applying a voltage to the first and second electrodes 28a and 28b and the third and fourth electrodes 31a and 31b, the arrangement state of the liquid crystal molecules is Is changed, the refractive index of light passing through the variable focus lens 25 is changed. As a result, the variable focus lens 25 functions as a concave lens or a convex lens by changing the focal length according to the arrangement state of the liquid crystal.

Therefore, as shown in FIG. 4, the focal length of the image generated in the A pixel on the flat panel display is changed by the variable focus lens 25, so that the viewer recognizes the image generated in the A pixel as the image generated in the B pixel. will be.

As described above, since the focal length of the variable focus lens 25 is changed according to the arrangement state of the liquid crystal, each pixel is adjusted by adjusting the voltage difference between the first and second electrodes 28a and 28b and the third and fourth electrodes 31a and 31b. By varying the focal length of the variable focus lens 25 in various ways, by providing a difference in depth of each pixel, a more natural three-dimensional stereoscopic image is easily realized.

Next, FIG. 5 is a partially exploded perspective view of the liquid crystal prism, and the liquid crystal prism 40 disposed after the variable focus lens unit 20 has left and right eye images implemented by the flat panel display 10 in the viewer's left and right eye directions. It divides the space into two parts.

More specifically, the liquid crystal prism 40 includes transparent fifth and sixth substrates 41 and 42 disposed to face each other at random intervals, and transparent agents formed on inner surfaces of the fifth and sixth substrates 41 and 42, respectively. A plurality of serrated prisms 45 and serrated prisms arranged between the 5 and 6 electrodes 43 and 44 and the fifth and sixth substrates 41 and 42 along the short axis direction of the screen (the Y axis in the drawing); And a third liquid crystal layer 46 encapsulated between the 45 and the fifth substrate 41.

The sawtooth prism 45 is formed such that the width W3 along the major axis direction of the screen (X axis in the drawing) is equal to the width of the semi-circular recess 23a constituting the vertical lenticular lens 23 described above. Each serrated prism 45 is disposed corresponding to the pixels of the flat panel display 10.

In addition, the fifth and sixth electrodes 43 and 44 are surface electrodes formed on the front surfaces of the fifth and sixth substrates 41 and 42, for example, and one of the electrodes, for example, the sixth electrode 44, has a ground voltage. The selection voltage is applied to the fifth electrode 43 to change the arrangement state of the liquid crystal molecules constituting the third liquid crystal layer 46 according to the voltage applied to the fifth electrode 43.

In addition, the third liquid crystal layer 46 encapsulated between the sawtooth prism 45 and the fifth electrode 43 has no voltage applied (see the right portion indicated as OFF in the drawing), and the long axis of each liquid crystal molecule When the electric field is formed in the third liquid crystal layer 46 in parallel along the short axis direction (Y-axis in the drawing) (see the left part shown in the drawing in the drawing), the long axis of each liquid crystal molecule is shortened on the screen (Fig. Y-axis) and rotates at any angle.

According to the above configuration, when the selection voltage is applied to the fifth electrode 43 while the ground voltage is applied to the sixth electrode 44, the refractive index of the third liquid crystal layer 46 is lower than that of the surrounding liquid crystal prism. The image provided to 40 is refracted in the right eye direction of the viewer, and when the ground voltage is applied to both the fifth electrode 43 and the sixth electrode 44, the refractive index of the third liquid crystal layer 46 becomes higher than the surroundings. Therefore, the image provided to the liquid crystal prism 40 is refracted in the viewer's left eye direction.

Therefore, the liquid crystal prism 40 is synchronized with the time division signal of the flat panel display 10, and when the flat panel display 10 implements a left eye image, a ground voltage is applied to the fifth electrode 43, and the flat panel display 10 has a right eye image. In this embodiment, a selection voltage is applied to the fifth electrode 43. As a result, the liquid crystal prism 40 separates the left and right eye images implemented by the flat panel display 10 in the left and right eye directions, respectively.

Next, as shown in FIG. 6, in the Fresnel lens 50 disposed after the liquid crystal prism 40, a plurality of band-shaped teeth 51 are arranged concentrically on one surface facing the liquid crystal prism 40. Each tooth 51 is a prism action. Therefore, the Fresnel lens 50 serves as a condenser lens to collect the light passing through the liquid crystal prism 40 to the viewer.

In this case, a configuration in which the Fresnel lens 50 is disposed after the variable focus lens unit 20 and the liquid crystal prism 40 is arranged after the Fresnel lens 50 may be arranged.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and various modifications and changes can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. Naturally, it belongs to the range of.

As described above, the stereoscopic image display device according to the present invention changes the focal length of the variable focus lens corresponding to each pixel, thereby solving the above-described problems of monocular adjustment and convergence angle, and has an effect such as a hologram with a limited viewing angle. As a result, a three-dimensional stereoscopic image may be more natural than a conventional auto-stereoscopic device even with a simpler configuration than a conventional electronic hologram and volumetric method.

Claims (10)

A flat panel display comprising a plurality of pixels for time-divisionally driving a left eye image and a right eye image; A plurality of vertical lenticular lens plates and horizontal lenticular lens plates, each of which is disposed in front of the flat display at a distance from the flat panel display, have a liquid crystal layer and electrodes embedded therein, and correspond to each pixel of the flat panel display. A variable focus lens unit forming a variable focus lens and changing a focal length of the variable focus lens according to a voltage applied to the electrodes; A pair of common electrodes disposed on the front surface of the variable focus lens unit, and having a liquid crystal layer interposed therebetween, and a plurality of tooth-shaped prisms arranged along a short axis direction of the screen on one side of the liquid crystal layer, Liquid crystal prism that controls the direction of refraction of light according to the voltage applied to the electrode to separate the left and right eye images of the flat panel display into the left and right eye directions of the viewer, respectively. Stereoscopic image display device comprising a. The method of claim 1, And a Fresnel lens in which a plurality of band-shaped teeth are arranged concentrically on a front surface of the liquid crystal prism. The method of claim 1, And a Fresnel lens in which a plurality of band-shaped teeth are arranged concentrically between the variable focus lens unit and the liquid crystal prism. The method of claim 1, And the flat panel display is a projection display or a liquid crystal display. The method of claim 1, The vertical lenticular lens plate, A vertical lenticular lens including first and second substrates disposed to face each other, a plurality of semi-circular recesses arranged along a short axis direction of the screen between the first and second substrates, the first substrate and the vertical lenticular A first liquid crystal layer encapsulated between the lenses, and first and second electrodes of stripe patterns perpendicular to each other at right angles on inner surfaces of the first and second substrates; The horizontal lenticular lens plate, A horizontal lenticular lens having third and fourth substrates disposed to face each other, a plurality of semi-circular recesses arranged along the major axis direction of the screen between the third and fourth substrates, the third substrate and the horizontal lenticular A second liquid crystal layer encapsulated between the lenses and third and fourth electrodes of a stripe pattern perpendicular to each other at right angles on the inner surfaces of the third and fourth substrates; And the intersection point of the vertical lenticular lens and the horizontal lenticular lens serves as the variable focus lens. The method of claim 5, And the width of the semi-circular concave portion of the vertical lenticular lens along the long axis direction of the screen is equal to the width of a pixel along the long axis direction of the screen. The method of claim 5, And the width of the semi-circular concave portion of the horizontal lenticular lens along the short axis direction of the screen is equal to the width of the pixel along the short axis direction of the screen. delete The method of claim 1, And the sawtooth prism has a width of each sawtooth prism along the long axis direction of the screen equal to the width of the semi-circular recess of the vertical lenticular lens along the long axis direction of the screen. The method of claim 1, And a liquid crystal prism to apply a selection voltage to any one of the pair of common electrodes in synchronization with the time division driving of the flat panel display.

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