KR20070108097A - Apparatus for displaying 3d image - Google Patents

Abstract

An apparatus for displaying a stereoscopic 3D image is provided to minimize the decrease of a resolution by adjusting a multiplexing pattern of a plurality of parallax images and an inclined angle of a lenticular lens and to prevent a liquid crystal panel from being bent. An apparatus for displaying a stereoscopic 3D image includes a liquid crystal panel(44) displaying a plurality of parallax images sampled and multiplexed to implement a stereoscopic 3D image. A stereoscopic 3D image filter is arranged to a front surface of the liquid crystal panel to separate the parallax images. A flat panel supporting plate(40) is attached on at least one of a front surface and a back surface of the liquid crystal panel to support the liquid crystal panel in such a manner that a form of the liquid crystal panel flattens. The flat panel supporting plate is a transparent glass plate.

Description

Stereoscopic Display Device {Apparatus for Displaying 3D Image}

The present invention relates to a stereoscopic image display device, and more particularly, to a stereoscopic image display device in which a resolution does not decrease even when the number of parallax images for each direction used to implement a stereoscopic image is increased.

In general, a stereoscopic image is recognized as a stereoscopic image by inputting different images into the viewer's left and right eyes and synthesizing the left and right images in the viewer's head. Therefore, in order to produce such a stereoscopic image, a device capable of displaying different images of the viewer's left eye and right eye is required. In the related art, a linear polarization type stereoscopic display device which separates a left eye image and a right eye image using stereoscopic glasses is a conventional device. Although used, there was the inconvenience of having the viewer wear glasses.

Therefore, methods for not wearing glasses have been proposed to solve this problem. These methods combine a flat-panel display device such as an LCD or a PDP to form a stereoscopic system by combining elements that separate images for each direction. This is again a lenticular lens sheet according to a device that separates images for each direction. Lenticular method using, Parallax method using Slit Array Sheet, Integral photography method using microlens array sheet, Interference phenomenon It is divided into a holography method using. Among them, the parallax method has the disadvantage that the brightness of the screen is dark because most of the light is blocked by the slit, and the integrative photography method and the holography method have the disadvantage that the amount of data processing is so large that it is not easy to realize in reality. Recently, attention has been focused on the lenticular method.

FIG. 1 illustrates a conventional stereoscopic image display apparatus using the lenticular method. As shown, the stereoscopic image display apparatus using the lenticular method is a flat display device 10 and a lenticular lens plate disposed on the front of the flat display device 10 displaying a plurality of directional images. (12), wherein the lenticular lens plate 12 is arranged such that its longitudinal axis 14 is parallel to the vertical axis of the flat panel display element 10, with the image placed primarily on the focal plane of the lenticular lens. It is arranged spaced apart from (10) by a predetermined distance. However, the stereoscopic image display apparatus using the conventional lenticular method using the four images shown in FIG. 1 has the same resolution as that of the parallax image for each direction before the vertical resolution is sampled as in FIG. Reduced to / 4. That is, the conventional lenticular method has a disadvantage in that the horizontal resolution is reduced to 1 / n (n: number of parallax images for each direction).

In order to solve the above disadvantages, as shown in FIG. 3, a method of disposing the lenticular lens 12 such that the longitudinal axis 16 of the lenticular lens 12 is inclined by a predetermined angle α is proposed. This method improves horizontal resolution at the expense of some vertical resolution. In detail, referring to FIG. 4, in FIG. 4, nine directional parallax images are used to implement a stereoscopic image. As shown, horizontal resolution is about 1/3, not 1/9, compared to the basic 2D resolution. It can be seen that the vertical resolution is reduced to about 1/3 compared to the conventional lenticular method of the conventional vertical direction, in which the resolution is not reduced. In other words, by balancing the horizontal and vertical resolution deterioration, the viewer looks as if the image quality is improved as compared with the conventional method. At this time, the inclination angle α of the vertical axis of the lenticular lens is defined by the following equation.

In this case, Hp represents the minimum unit pixel period in the horizontal direction, Vp represents the minimum unit pixel period in the vertical direction, and R represents an integer of 2 or more, indicating the number of rows used in the plurality of image arrays. For example, the lenticular lens plate 12 is inclined such that α has a value such as 9.4 ° or 6.3 °. Here, the parallelogram 18 shown in Fig. 4 represents the unit resolution in the inclined lenticular method, and the rectangle 20 represents the unit resolution in the 2D image.

When viewing a stereoscopic image using the stereoscopic image display apparatus using the lenticular lens method as described above, there is an area where an observer can observe the optimal image, which is called unit stereoscopic space. Therefore, the larger the size of the unit stereoscopic space is, the wider the space for the observer to normally view stereoscopic images without the presence of the stereoscopic, and the size of the unit stereoscopic space is the size of the horizontal distance of the unit stereoscopic space (L). ), The horizontal distance L is calculated by the following equation.

L = m × d

Here, m represents the number of parallax images for each direction constituting the unit stereoscopic image, and d is given as a distance in the unit stereoscopic space corresponding to one parallax image for each direction. Therefore, to increase the size of the unit stereoscopic space, L must be increased, and in order to increase L, the number of parallax images for each direction is increased or m is a distance from the unit stereoscopic space corresponding to one direction parallax image. It can be seen that d should increase. This will be described in detail with reference to FIG. 5. FIG. 5A illustrates a case in which four directions of parallax images are used (m = 4) and FIG. 5B illustrates a case in which six directions of parallax images are used (m = 6). As can be seen, when d or m increases, L increases, and when L increases, the unit three-dimensional space can be seen to expand.

However, d should be smaller than the distance between both eyes of the observer, so there is a limit to increasing the size, but m must be increased, but in general, an increase of m causes a decrease in resolution. Accordingly, in the stereoscopic image display apparatus using the lenticular method, a stereoscopic image display apparatus capable of expanding a unit stereoscopic space without degrading the resolution is required.

Meanwhile, in the case where the flat panel display device 10 displaying a plurality of direction-specific parallax images is implemented by an LCD in the stereoscopic image display device, as illustrated in FIGS. 6A and 6B, the LCD is enlarged or disposed before and after the LCD. Due to the difference in thermal expansion or thermal contraction characteristics of the polarizing plates (not shown), the LCD may be bent forward or backward, which causes a three-dimensional image filter 12 such as a lenticular lens plate and a flat panel display element 10 implemented by the LCD. There is a problem that the distance (l) between them is not constant over the entire screen, thereby greatly deteriorating the three-dimensional effect.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problem, by adjusting a tilting angle of the lenticular lens plate and a multiplexing pattern of parallax images for each direction, a stereoscopic image display device capable of expanding a unit stereoscopic space while minimizing a resolution reduction. It is technical problem to provide.

Another object of the present invention is to provide a three-dimensional image display device that can prevent the bending of the liquid crystal panel used in the three-dimensional image display device.

According to an aspect of the present invention, a stereoscopic display device according to an aspect of the present invention includes a flat panel display device displaying a plurality of directional parallax images sampled and multiplexed to realize a stereoscopic image, and a vertical axis of the flat display device. And a lenticular lens plate disposed to be inclined by a predetermined angle α with the vertical axis of the flat panel display device, wherein the angle is calculated by a formula α = arctan (3Hp / 5Vp), where Hp is a minimum unit in the horizontal direction. A pixel period represents a sub pixel period, and Vp represents a minimum unit pixel period in a vertical direction.

At this time, the number of parallax images for each direction constituting one unit stereoscopic image among the stereoscopic images is a multiple of 5. In one embodiment, when the unit stereoscopic image is composed of 25 parallax images for each direction, the 25 The parallax image for each direction is multiplexed into five subpixels in the horizontal and vertical directions, respectively, and the width of one lenticular lens constituting the lenticular lens plate is divided into five subpixels in the horizontal direction constituting the flat panel display element. Correspondingly formed.

In a modified embodiment, when the unit stereoscopic image is composed of 40 direction-specific parallax images, the 40 direction-specific parallax images are multiplexed into 8 subpixels in a horizontal direction and 5 subpixels in a vertical direction. The width of one lenticular lens constituting the lenticular lens plate is formed to correspond to eight subpixels in the horizontal direction constituting the flat panel display element.

The stereoscopic image display device according to an embodiment of the present invention for achieving the above-described object is disposed on the front of the liquid crystal panel and a liquid crystal panel in which a plurality of direction-specific parallax images sampled and multiplexed for displaying a stereoscopic image are displayed. A stereoscopic image filter separating the parallax images for each of the plurality of directions and a flat plate supporting plate for supporting the liquid crystal panel so that the shape of the liquid crystal panel becomes flat by being attached to at least one of the front and rear surfaces of the liquid crystal panel. It is done.

As described above, according to the present invention, the size of the unit stereoscopic space can be maximized while minimizing the resolution degradation by adjusting the inclination of the multiplexing patterns of the plural directional parallax images and the lenticular lens plate.

In addition, according to the present invention, when the LCD is used as a flat panel display element, by installing a bending prevention film on the outer side of the polarizing plate included in the LCD to prevent the LCD from warping and to maintain a constant distance between the stereoscopic image filter and the LCD to the observer There is an effect that can provide an optimal three-dimensional image.

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention that can specifically realize the above object will be described. The same components as in the prior art are given the same names and the same reference numerals for convenience of description, and detailed description thereof will be omitted.

7 shows a stereoscopic image display device according to an embodiment of the present invention. As shown, the stereoscopic image display device is disposed in front of the flat panel display element 22 and the flat panel display element 22 on which a plurality of sampled and multiplexed direction-specific parallax images are displayed to separate a plurality of direction parallax images. The main includes a lenticular lens plate 24, wherein the lenticular lens plate 24 is disposed to be spaced apart from the flat panel display element 22 by a predetermined distance l so that the image is placed on the focal plane of the lenticular lens. In one embodiment, the flat panel display element 22 may be implemented as an LCD or PDP. When the flat panel display element 22 is implemented as an LCD as shown in FIG. The image display device further includes a backlight 26 as a light source.

In this case, in order to maximize the size of the unit stereoscopic space while minimizing the resolution degradation, the lenticular lens plate 24 illustrated in FIG. 7 is disposed to be inclined by a predetermined angle α on the front surface of the flat panel display element 22. The angle is set by adjusting a pattern in which the plurality of parallax disparity images are multiplexed in one unit stereoscopic image forming a stereoscopic image. That is, the present invention extends the size of the unit stereoscopic space by increasing the number of parallax images for each direction, and minimizes the resolution reduction by adjusting the inclination of the lenticular lens plate 24 and the multiplexing pattern of the parallax images for each direction.

A process of defining the angle at which the multiplexing pattern of the parallax image for each direction and the lenticular lens plate are inclined will be described in detail with reference to FIGS. 8 to 9. First, as shown in FIG. 8, the parallax image for each direction is divided into n direction parallax images PV1 using n cameras C1, C2,..., And Cn (27a, 27b,..., 27n). It is generated by obtaining, PV2, ...., PVn). The generated n direction disparity images are multiplexed into a predetermined pattern after the sampling process to form one unit stereoscopic image.

As illustrated in FIG. 8, the stereoscopic image display apparatus generates a unit stereoscopic image 28 by using 5 m (m = natural numbers) direction-specific parallax images. The number of parallax images for each direction used to generate a unit stereoscopic image may be 25, 30, 35, 40, 45, etc., among which 25 or 40 are implemented in consideration of an optimal resolution. Most preferred. Hereinafter, for convenience of description, the present invention will be described by implementing a unit stereoscopic image using 25 direction-specific parallax images.

As illustrated in FIG. 9, the unit stereoscopic image 28 including 25 parallax images for each direction is repeated on the flat panel display 22 in the horizontal direction and five subpixels downward in the vertical direction. It is shifted by three subpixels to the left and repeated. In addition, the 25 disparity images for each direction disposed in one unit stereoscopic image are arranged in five subpixels in the horizontal and vertical directions according to a predetermined rule, and the pattern in which the first five disparity images for each direction are arranged repeatedly is repeated. As a result, 25 parallax images for each direction are sequentially arranged.

More specifically, the third, eighth, thirteenth, eighteenth, and twenty-third direction parallax images are disposed in the first subpixel of the first row among the subpixels constituting the unit stereoscopic image from right to left. Disparity images for each of the fifth, tenth, fifteenth, twenty, and twenty-fifth directions are arranged in the subpixels of the second row that are moved by one subpixel to the left based on one row, The second, seventh, twelfth, seventeenth, and twenty-second direction parallax images are arranged in the subpixels of the third row from the right, and are moved by one subpixel to the left of the third row. Fourth, ninth, fourteenth, nineteenth, and twenty-fourth direction parallax images are disposed from the right to the left in the fourth row of pixels, and the first, sixth, and the fifth rows are arranged from the right to the left in the fifth row of subpixels. A parallax image for each of the 11th, 16th, and 21st directions is disposed.

In the case where disparity-specific parallax images are arranged as illustrated in FIG. 9, the vertical axis 25 of the lenticular lens plate 24 is a flat panel display device to display 25 parallax parallax images using one lenticular lens without degrading the resolution. The angle α at which the longitudinal axis 25 of the lenticular lens plate 24 is inclined may be calculated using the triangle 29 illustrated in FIG. 8. If it is formulated, it is as follows.

Here, Hp represents the minimum unit pixel period in the horizontal direction and Vp represents the minimum unit pixel period in the vertical direction.

At this time, one lenticular lens 24a constituting the lenticular lens plate 24 is formed to correspond to five subpixels in the horizontal direction.

In the above-described embodiment, the unit stereoscopic image 28 has been described as using 25 parallax parallax images. However, in the modified embodiment, the unit stereoscopic image is constructed using 40 parallax parallax images (not shown). It can also be configured. At this time, as in the case of the unit stereoscopic image 28 composed of 25 parallax disparity images, the unit stereoscopic image composed of 40 parallax parallax images is also adjacent to each other in the horizontal direction on the flat panel display element 22. It is repeated and shifted by 5 subpixels down and 3 subpixels to the left in the vertical direction. However, 40 direction-specific parallax images arranged in one unit stereoscopic image are arranged in 8 subpixels in the horizontal direction and 5 subpixels in the vertical direction, where one lenticular lens constituting the lenticular lens plate is provided. Is formed to have a width that can include eight subpixels in the horizontal direction. A method of arranging 40 direction-specific parallax images in a subpixel is as follows.

First, the third, eighth, thirteenth, eighteenth, twenty-third, eighth, thirteenth, eighteenth, twenty-third, thirty-eighth, thirty-eighth, and thirty-eighth directions of the subpixels in the uppermost row among the subpixels of the unit stereoscopic image; The fifth, tenth, fifteenth, twenty, twenty-fifth, thirty, thirtieth images are disposed, and the fifth, tenth, fifteenth, twenty, twenty, thirtyth, thirtyth, thirtyth, and thirtyth subpixels of the second row are arranged by shifting one subpixel to the left based on the first row. , Parallax images for each of the 35th and 40th directions are disposed, and the second, seventh, twelfth, seventeenth, twenty-second, twenty-second, thirty-seventh, thirty-seventh, and thirty-seventh images are disposed on the subpixels in the third row. The parallax image for each of the first directions is disposed, and the fourth pixel, the fourth, ninth, fourteenth, nineteenth, twenty-fourth, A parallax image for each of the 29th, 34th, and 39th directions is disposed, and the first, sixth, eleventh, sixteenth, twenty-first, twenty-sixth, thirteenth, and thirteenth pixels are disposed from the right in the fifth pixel. 36th direction star This arrangement being a difference image of 40 parallax images each direction are arranged both on the sub-pixel.

FIG. 10 is a view illustrating a comparison of the resolution of the stereoscopic image display device according to the present invention and the resolution of the stereoscopic image display device according to the prior art, and FIG. 10a illustrates a unit stereoscopic image in 25 directions according to an embodiment of the present invention. The lenticular lens plate 24 is configured to be inclined by an angle calculated by Equation 3, and FIG. 10B uses a nine-dimensional parallax image according to the prior art. The lenticular lens plate 24 is inclined by the angle calculated by the equation (1). In FIGS. 10A and 10B, the rectangles 30 and 32 represent unit resolutions due to the effects of the lenticular lens plates 24 and 12, and the smaller the areas A and B, the higher the resolution. As shown, the area (A) of the unit resolution of the present invention using 25 directional parallax images is smaller than the area B of the conventional unit resolution using 9 directional parallax images, so that the stereoscopic image according to the present invention. It can be seen that the resolution of the display device is higher. That is, considering Equation 2, since the present invention uses more parallax images for each direction than in the related art, it can be seen that not only the size of the unit stereoscopic space is increased but also the resolution is also increased.

On the other hand, Figure 11 is a three-dimensional image that can prevent the bending of the LCD by attaching a support plate on the outside of the LCD, when the flat panel display element 22 included in the three-dimensional image device is implemented as an LCD as shown in FIG. Show the display device. As shown, the support plates 40 and 42 are attached to the outside of the polarizing plates 36 and 38 constituting the LCD in the LCD of the stereoscopic image display device according to the exemplary embodiment of the present invention. The support plates 40 and 42 may be formed of a transparent glass plate or a transparent plastic plate like the transparent substrates 46 and 48 disposed outside the liquid crystal 44.

In the above-described embodiment, the supporting plates 40 and 42 are described as being attached to both the outer sides of the polarizing plates 36 and 38. However, in the modified embodiment, the supporting plates 40 and 42 are formed only on the outer side of any one of the polarizing plates 36 and 38. May be In addition, the above-described stereoscopic image display apparatus may use not only a lenticular lens plate but also a slit array plate as the stereoscopic image filter 50 for separating a plurality of directional parallax images.

The present invention is not limited to the above-described embodiments, and such modifications are included within the scope of the present invention even though modifications may be made by those skilled in the art to which the present invention pertains.

In the above-described stereoscopic image display device, an anti-bending film is installed outside the polarizer included in the LCD to prevent the LCD from bending and maintain a constant distance between the stereoscopic image filter and the LCD to provide an optimal stereoscopic image to the viewer. There is an effect that it can provide.

1 is a view showing a conventional stereoscopic image display apparatus using a lenticular method.

FIG. 2 is a diagram illustrating a resolution reduction in the stereoscopic image display device shown in FIG. 1. FIG.

3 is a view showing another conventional stereoscopic image display using a lenticular method.

FIG. 4 is a diagram illustrating a resolution reduction in the stereoscopic image display device shown in FIG. 3.

5 is a diagram illustrating a unit stereoscopic space in a conventional stereoscopic image display using a lenticular method.

FIG. 6 is a view illustrating a warpage phenomenon of an LCD when the flat panel display device is implemented as an LCD. FIG.

7 is a view showing a stereoscopic image display device according to an embodiment of the present invention using a lenticular method.

8 is a view illustrating a process of generating a plurality of direction-specific parallax images.

FIG. 9 is a diagram illustrating an inclination angle of a multiplexing pattern of a plurality of directional parallax images and a lenticular lens plate according to an embodiment of the present invention. FIG.

10 is a view showing a comparison of the resolution of the stereoscopic image display device according to the present invention and the resolution of the stereoscopic image display device according to the prior art.

11 is a view showing a stereoscopic image display device that can prevent the warpage of the LCD used as a flat panel display element.

Claims (4)

A liquid crystal panel displaying a plurality of direction-specific parallax images sampled and multiplexed to realize a stereoscopic image; A stereoscopic image filter disposed on the front surface of the liquid crystal panel to separate the parallax images for each direction; And A flat plate supporting plate attached to at least one of the front and rear surfaces of the liquid crystal panel to support the liquid crystal panel so that the shape of the liquid crystal panel is flat; Stereoscopic display device comprising a. The flat plate support plate of claim 1, A stereoscopic image display device, characterized in that formed of a transparent glass plate. The flat plate support plate of claim 1, Stereoscopic display device characterized in that formed of a transparent plastic plate. The stereoscopic image filter of claim 2 or 3, A stereoscopic image display device of a portable image display device, characterized in that implemented by a lenticular lens plate or a slit array plate.

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