KR20070072132A - Stereoscopic display - Google Patents

Abstract

The present invention relates to a stereoscopic image display device for selectively implementing a planar image (2D) and a stereoscopic image (3D), and to improve the brightness when driving the stereoscopic image (3D), the display panel for displaying an image; And a switching panel configured to include a polymer layer and a liquid crystal layer to selectively implement a stereoscopic image and a planar image.

Description

Stereoscopic Image Display {AUTOSTEREOSCOPIC 3D DISPLAY DEVICE}

1 is a view schematically showing a configuration of a stereoscopic image display device.

Figure 2 is a view showing in detail a conventional switching panel.

3 is a view schematically showing the configuration of a three-dimensional image display device according to the present invention for implementing a planar image.

4 is a view schematically showing the configuration of a three-dimensional image display device according to the present invention for implementing a three-dimensional image.

5 is a diagram showing a schematic configuration of a stereoscopic image display device according to another embodiment of the present invention.

*** Explanation of symbols for main parts of drawing ***

120, 220: switching panel 121, 221: first substrate

122, 222: first transparent electrode 123, 223: second substrate

124 and 224: second transparent electrodes 125 and 225: liquid crystal unit

127, 227: polymer portion 129, 229: switching portion

130, 230: display panel 150, 250: backlight unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a display device, and more particularly, to a stereoscopic image display device for selectively implementing a planar image (2D) and a stereoscopic image (3D) and improving luminance when implementing a stereoscopic image.

There are physiological and psychological factors in which a person feels a three-dimensional effect. In stereoscopic image display technology, a three-dimensional effect of an object is generated by using a binocular parallax, which is the biggest factor that generates a three-dimensional effect at a short distance. .

As a display method of a stereoscopic image, there are two methods of wearing glasses and a method of not wearing glasses.

The way of wearing the glasses is the anaglyph method, which uses blue and red sunglasses, and the polarization method, which uses glasses with different polarizations, and the time-divided polarization, which is repeated periodically and synchronized with this cycle. There is a time division method using glasses with polarized shutters. However, the method of wearing glasses has problems such as inconvenience of wearing glasses and difficulty in observing an object other than an image.

Therefore, recently, studies on the method of not wearing glasses have been actively conducted. As a representative example of the method of not wearing glasses, a lenticular lens plate having vertically arranged cylindrical lenses is provided in front of the display panel. There are a lenticular method and a parallax barrier method installed in the.

Moreover, with the development of liquid crystal display technology, mechanical shutters are replaced by liquid crystal shutters, and thus, stereoscopic and planar images can be selectively converted and used.

1 schematically illustrates a configuration of a stereoscopic image display device using a parallax barrier method, and more particularly, to a stereoscopic image display device capable of selectively switching a stereoscopic image and a planar image.

As shown in the figure, the stereoscopic image display device 1 is composed of a backlight light source 40, the display panel 30 and the switching panel 20. The switching panel 20 includes a non-transmissive slit portion and a transparent transmissive slit portion that are opaque and have a predetermined width when an electric signal is applied, and the non-transparent slit portions and the transmissive slit portions are alternately arranged.

The observer 10 sees the display panel 30 through the light transmitting slit portion of the switching panel 20. In this case, the left eye L of the observer 10 passes through the light transmitting slit portion of the switching panel 20. ), The right eye R of the observer 10 sees the right eye region Rp of the display panel 30 through the light transmitting slit portion of the switching panel 20.

As described above, the left eye L and the right eye R of the observer 10 respectively look at different areas of the display panel 30. In this case, the display panel 30 corresponds to the left eye and the right eye of the observer 10. FIG. Images are displayed in the left eye area Lp and the right eye area Rp, respectively. As a result, the observer feels a three-dimensional effect due to binocular parallax.

The structure of the switching panel 20 of the conventional stereoscopic image display device as described above will be described in more detail with reference to FIG. 2.

As shown in the figure, the switching panel 20 of the conventional stereoscopic image display device is a transparent first substrate 21 and the second substrate 26, and the first substrate 21 and the second substrate 26. It consists of a liquid crystal layer 25 formed between. Polarizing plates 22 and 27 are attached to the outer side of the first substrate 21 and the second substrate 26, respectively, and are made of a transparent material such as indium tin oxide (ITO) of the first substrate 21. The first electrode 23 is patterned, and a second electrode 28 made of the same material as the first electrode 23 is formed on the inner front surface of the second substrate 26.

When an electrical signal is applied to the first electrode 23 and the second electrode 28, the liquid crystal formed between the first electrode and the second electrode 28 is driven to form the non-transmissive slit portion B. do.

As a result, the stereoscopic image mode and the planar image mode may be selectively switched depending on whether the electrical signal is applied to the first electrode and the second electrode 28. That is, when a signal is applied to the first electrode 23 and the second electrode 28, a non-transmissive slit portion B is formed in a region where the first electrode 23 is formed to implement a stereoscopic image mode. When a signal is applied to the first electrode 23 and the second electrode 28, the first electrode 23 region forms a light transmitting slit portion T, thereby implementing a planar image mode.

However, in the switching panel 20 of the conventional stereoscopic image display device configured as described above, since the non-transmissive slit portion B, through which light is not transmitted, is formed by driving the liquid crystal layer 25 in the stereoscopic image mode, Due to the loss of light that cannot be transmitted through the region, there is a problem in that the luminance is lowered when the stereoscopic image is implemented.

Accordingly, an object of the present invention is to provide a display device capable of improving luminance by minimizing light transmitted to a non-transmissive slit portion.

Other objects and features of the present invention will be described in detail in the configuration and claims of the following invention.

In order to achieve the above object, the stereoscopic image display apparatus of the present invention includes a display panel for displaying an image; A switching panel configured to continuously configure a polymer part and a liquid crystal part to selectively implement a stereoscopic image and a planar image; And a backlight unit for supplying light to the switching panel.

The switching panel, the first and second transparent substrate; First and second electrodes formed on opposite surfaces of the first and second transparent substrates; And a switching part in which a polymer part and a liquid crystal part are alternately formed between the first electrode and the second electrode, and the interface between the polymer part and the liquid crystal part is inclined. At this time, the interface between the polymer portion and the liquid crystal portion is symmetrical with respect to the vertical axis of the switching panel.

In addition, the width of the liquid crystal part decreases toward the upper layer, and the width of the polymer part increases toward the upper layer. In this case, the refractive index of the liquid crystal part must be larger than the refractive index of the polymer part.

In addition, the width of the liquid crystal part increases toward the upper layer, and the width of the polymer part may be designed to decrease toward the upper layer. In this case, the refractive index of the liquid crystal part must be smaller than the refractive index of the polymer part.

The display panel may include one of a liquid crystal display (LCD) panel, a plasma display panel (PDP) panel, a field emission display (FED) panel, an electric luminescence (EL) panel, and a vacuum fluorescent display (VFD) panel. have.

As described above, the present invention uses the refractive anisotropy of the liquid crystal, and by changing the refractive index of the liquid crystal depending on whether an electric field is applied or not, it is possible to improve the luminance when implementing the stereoscopic image by using the total reflection characteristic of the light.

That is, in the present invention, the polymer part and the liquid crystal part having different refractive indices are sequentially arranged alternately, and the interface between them is inclined so that a part of the light incident on the non-transmissive slit region is reflected to the transmissive slit portion to realize luminance in the stereoscopic image. Improve. In general, when the light is incident on the smaller refractive index in a material having a higher refractive index, all the light coming over the grain boundary angle is totally reflected, and the present invention improves the luminance of the transmissive slit by using this characteristic of the light.

Hereinafter, the stereoscopic image display device according to the present invention will be described in more detail with reference to the accompanying drawings.

3 and 4 are cross-sectional views schematically showing a stereoscopic image display device according to the present invention. FIG. 3 illustrates a planar image 2D implementation, and FIG. 4 illustrates a stereoscopic image 3D implementation.

As shown in the figure, the stereoscopic image display device 100 of the present invention is a display panel 130 for displaying an image, a switching panel 120 disposed below the display panel 130 and the switching panel ( And a backlight unit 150 for supplying light to the display panel 130.

The display panel 130 may be selected from one of a liquid crystal display (LCD) panel, a plasma display panel (PDP) panel, a field emission display (FED) panel, an electric luminescence (EL) panel, and a vacuum fluorescent display (VFD) panel. In addition, all flat panel display panels can be applied.

The switching panel 120 forms a light transmitting slit portion T and a non-light transmitting slit portion B according to whether the liquid crystal is driven, and the display panel 130 is a stereoscopic image (eg, the display panel 130) by the switching panel 120. 3D) or planar image 2D is selectively implemented.

In more detail, the switching panel 120 of the present invention includes the transparent first and second substrates 121 and 123 and the switching unit 129 and the interposed between the first and second substrates 121 and 123. The first and second transparent electrodes 122 and 124 are formed on opposite surfaces of the first and second substrates 121 and 123, respectively, to drive the switching unit 129.

The switching unit 129 is configured by successively alternating the liquid crystal unit 125 and the polymer unit 127 having different refractive indices, and the interface 131 has an inclined surface with respect to the vertical direction of the switching panel 120.

The width of the liquid crystal part 125 decreases toward the upper layer, and the width of the polymer part 127 increases toward the upper layer, and the refractive index of the liquid crystal part 125 is realized in order to realize a stereoscopic image. It should be larger than the refractive index of the polymer portion 127.

In addition, the width of the liquid crystal part 125 increases toward the upper layer, and the width of the polymer part 127 decreases toward the upper layer, and in this case, the liquid crystal part for realizing a stereoscopic image. The refractive index of 125 should be smaller than the refractive index of the polymer portion 127. Detailed description thereof will be provided in the following embodiments.

Here, it is assumed that the liquid crystal of the liquid crystal unit 125 is an N type (negitive type) liquid crystal having a long refractive index lower than a short refractive index. However, in the present invention, a P-type (positive type) liquid crystal having a larger refractive index than that of the short axis is also possible.

The liquid crystal unit 125 may selectively implement a planar image and a stereoscopic image by changing a refractive index value depending on whether signals are applied to the first and second transparent electrodes 122 and 124. In more detail, when a signal is applied to the first and second transparent electrodes 122 and 124, the liquid crystal unit 125 may include the first and second transparent electrodes 122 and 124 as shown in FIG. 3. The long axes of the liquid crystal molecules are arranged in parallel with the electric field direction by driving along the electric field therebetween. In this case, the light supplied from the backlight unit 150 disposed below the switching panel 130 passes through both the liquid crystal unit 125 and the polymer unit 127 to implement a planar image. That is, although the refractive indices of the liquid crystal part 125 and the polymer part 127 are different, the light entering the liquid crystal part 125 is refracted by the polymer part 127 and transmitted, so that an observer can see an image appearing on the display panel 130. As seen through the switching panel 120, the observer sees the planar image 2D.

On the other hand, when no signal is applied to the first and second transparent electrodes 122 and 124, as illustrated in FIG. 4, the long axis of the liquid crystal unit 125 is parallel to the switching panel 130 along the initial alignment direction. Are arranged. At this time, most of the light supplied from the backlight unit 150 disposed below the switching panel 130 passes through the liquid crystal unit 125, and the light directed toward the polymer unit 127 is the liquid crystal unit 125 and the polymer. By total reflection at the interface of the portion 127 to form a non-transparent slit portion (B) in the polymer portion 127, to realize a three-dimensional image.

That is, when the refractive index of the liquid crystal part 125 is greater than the refractive index of the polymer part 127, the light coming in at a critical angle or more is totally reflected by the boundary surface 131 of the liquid crystal part 125 and the polymer part 127, whereby the polymer part Since it does not transmit 127, the polymer part 127 implements the non-transmissive slit part B, and the liquid crystal part 125 implements the transmissive slit part T.

In more detail, the observer sees an image displayed on the display panel 130 through the projection slit portion T of the switching panel 120. The left eye and right eye of the observer are viewed. Even though the light penetrates through the same transmission slit portion T, the different regions of the display panel 130 are seen. That is, the left eye sees the left eye correspondence pixel on the display panel 130, and the right eye sees the right eye correspondence pixel of the display panel 130, respectively. Accordingly, images corresponding to the left and right eyes are displayed on the corresponding pixels of the display panel 130 by the image processor (not shown), so that the viewer feels a three-dimensional effect.

In this case, as the light to be transmitted to the polymer part 127 is reflected by the liquid crystal part 125 and transmitted to the light transmitting slit part T, the brightness of the light transmitting slit part T is improved, so that the brightness of the stereoscopic image is realized. It will be possible to improve. That is, when the electric field is applied to the first and second transparent electrodes 122 and 124, the polymer part 127 transmits the light entering the liquid crystal part 125 to implement the light transmitting slit part T, but the first If no signal is applied to the second transparent electrodes 122 and 124, the light entering the liquid crystal part 125 is totally reflected at the boundary surface 131 to implement the non-transparent slit part B. However, since almost all of the light coming from the backlight unit 150 enters through the liquid crystal unit 125, almost all of the light to be transmitted to the polymer unit 127 is totally reflected to pass through the liquid crystal unit 125 and the light transmitting slit. It will come out as negative (T). This is due to the refractive anisotropy of the liquid crystal part 125. The refractive index is varied by changing the arrangement of liquid crystal molecules by an electric field, so that light incident on the polymer part 127 is selectively transmitted or totally reflected.

In addition, the total reflection reflects only the light coming in from the critical angle, and the light coming in from the critical angle is transmitted through the polymer part 127 as it is, thereby increasing the luminance of the non-transparent slit part T, but forming a parallax barrier. It is possible to achieve the effect of improving the luminance as a whole in the stereoscopic image.

Here, when the critical angle is referred to as θc and the refractive indices of the liquid crystal unit 125 and the polymer unit 127 are defined as n ₁ and n ₂ , respectively, the critical angle may be obtained as shown in Equation (1).

In this case, in order for total reflection to occur, the refractive index n _{1 of the} liquid crystal part must be greater than the refractive index n ₂ of the polymer part. Therefore, when the stereoscopic image is implemented, a material having a refractive index greater than that of the polymer portion may be used when implementing the stereoscopic image, and the refractive index of the liquid crystal portion may be smaller or greater than the refractive index of the polymer portion when implementing the planar image.

As described above, when a signal is applied to the first and second transparent electrodes, a planar image is realized, and when a signal is not applied, the stereoscopic image is implemented. The refractive index of the short axis of the liquid crystal molecule is greater than the refractive index of the long axis. This is because an N-type liquid crystal is used. When a P-type liquid crystal having the opposite characteristics is used, when an electric field is applied to the first and second transparent electrodes 122 and 124, the refractive index of the liquid crystal unit 125 increases, thereby realizing a stereoscopic image. When the signal is not applied, the planar image is realized because the refractive index becomes small.

Meanwhile, the width of the liquid crystal part 125 increases toward the upper layer and the width of the polymer part 127 decreases toward the upper layer, thereby realizing a stereoscopic image.

5 shows another embodiment of the present invention. In the stereoscopic image display device according to the present embodiment, all configurations except for the switching panel are the same as in the previous embodiment, and a detailed description thereof will be omitted.

As shown in the drawing, the stereoscopic image display apparatus 200 according to the present embodiment includes a display panel 230 for displaying an image, a switching panel 220 disposed below the display panel 230, and the switching panel. And a backlight unit 250 for supplying light to the display panel.

The switching panel 220 forms a light transmitting slit portion T and a non-light transmitting slit portion B according to whether liquid crystal is driven or not, and the display panel 230 is a stereoscopic image by the switching panel 220. 3D) or planar image 2D is selectively implemented.

In the present exemplary embodiment, the switching panel 220 includes the transparent first and second substrates 221 and 223, the switching unit 229 interposed between the first and second substrates 221 and 123, and the first and second substrates 121 and 123. And first and second transparent electrodes 122 and 124 which are formed on opposite surfaces of the second and second driving electrodes 229.

The switching unit 229 is composed of the liquid crystal unit 225 and the polymer unit 227 having different refractive indices consecutively alternately, and the interface 231 faces the inclined surface 231 with respect to the vertical direction of the switching panel 220. The width of the liquid crystal part 225 increases toward the upper layer, and the width of the polymer part 227 decreases toward the upper layer.

In addition, in this embodiment, in contrast to the previous embodiment (refer to FIGS. 3 and 4), the refractive index of the liquid crystal unit 225 should be smaller than that of the polymer unit 227 in order to realize a stereoscopic image. The light transmitting slit portion T is formed, and the liquid crystal portion 225 forms the non-light transmitting slit portion B.

When the stereoscopic image is implemented, the light incident on the polymer part 227 at the grain boundary angle or more is totally reflected at the interface 231 between the polymer part 227 and the liquid crystal part 225 to transmit light slits of the polymer part 227. It contributes to the luminance improvement of (T).

As described above, the present invention provides a stereoscopic image display device that can selectively implement a planar image and a stereoscopic image by using a switching panel composed of a polymer portion and a liquid crystal portion alternately, and can improve luminance when implementing a stereoscopic image. do. That is, the light incident to the non-transmissive slit portion is minimized, and the light transmitted to the transmissive slit portion is maximized, thereby improving luminance.

In this case, in order to maximize the light transmitted to the light-transmitting slit part, the present invention is configured so that the polymer part and the liquid-crystal part alternately continuously, and the width of the liquid crystal part or the polymer part that makes the light-transmitting slit part for the stereoscopic image is narrowed toward the top. In addition, the liquid crystal part or polymer part that makes the non-transmissive slit part is designed to be wider as it goes upward, and the light entering the non-transmissive slit part by varying the refractive indices of the liquid crystal part and the polymer part is the interface (the interface between the liquid crystal part and the polymer part). ) Is totally reflected to transmit the light to the light transmitting slit part.

In the present invention, if the conditions of the transfer reflection at the interface between the liquid crystal portion and the polymer portion are satisfied when the three-dimensional image is implemented, both types of liquid crystals, for example, N-type liquid crystals and P-type liquid crystals are possible, and the material of the polymer is limited to a specific material. I never do that.

As described above, according to the present invention, when the stereoscopic image is implemented, the switching panel is configured to totally reflect the light transmitted to the non-transmissive slit portion to the transmissive slit portion, thereby enabling to implement a high-brightness stereoscopic image.

Claims (10)

A display panel displaying an image; A switching panel composed of a polymer part and a liquid crystal part to selectively implement a stereoscopic image and a planar image; And And a backlight unit for supplying light to the switching panel. The method of claim 1, wherein the switching panel, First and second transparent substrates; First and second electrodes formed on opposite surfaces of the first and second transparent substrates; And And a switching unit in which the polymer unit and the liquid crystal unit are alternately formed between the first electrode and the second electrode. The method of claim 2, And a boundary surface between the polymer portion and the liquid crystal portion is inclined. The method of claim 3, And a boundary surface of the polymer portion and the liquid crystal portion is symmetrical with respect to the vertical axis of the switching panel. The method of claim 4, wherein And the width of the liquid crystal part decreases toward the upper layer, and the width of the polymer part increases toward the upper layer. The method of claim 5, And a refractive index of the liquid crystal part is greater than that of the polymer part. The method of claim 4, wherein And the width of the liquid crystal part increases toward the upper layer, and the width of the polymer part decreases toward the upper layer. The method of claim 7, wherein And a refractive index of the liquid crystal portion is smaller than that of the polymer portion. The method of claim 1, And the display panel is a liquid crystal display (LCD) panel. The display panel of claim 1, wherein the display panel comprises: 3. A stereoscopic image display device comprising one of a plasma display panel (PDP) panel, a field emission display (FED) panel, an electric luminescence (EL) panel, and a vacuum fluorescence display (VFD) panel.

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