KR20110128020A - Stereoscopic image display device and drving method thereof - Google Patents

Abstract

PURPOSE: A three-dimensional image display apparatus and an operation method thereof are provided to arrange a reflection pattern reflecting light generated from pixels on a substrate of a display panel, thereby increasing the luminance of the display panel in a three-dimensional image without adjusting driving voltage. CONSTITUTION: A display panel(10) comprises a first substrate with arranged pixels and a second substrate facing to the first substrate. A barrier(21) partly blocks an edge part of each pixel. A reflection pattern(11) is arranged in a part facing a non-luminous part between the pixels. The reflection pattern reflects light emitted from the pixels to the pixel side. A reflective film(12) reflects the light reflected by the reflection pattern and transmits the light projected from the pixels at the same time.

Description

Stereoscopic Display and Driving Method {STEREOSCOPIC IMAGE DISPLAY DEVICE AND DRVING METHOD THEREOF}

The present invention relates to a stereoscopic image display device and a driving method thereof.

The stereoscopic image display apparatus is divided into a binocular parallax technique and an autostereoscopic technique. The binocular parallax method uses a parallax image of the left and right eyes with a large stereoscopic effect, and there are glasses and no glasses, both of which are put to practical use.

The spectacle method displays the polarization of the left and right parallax images on the direct-view display device or the projector in a manner of changing the polarization of the left and right parallax images, and implements a stereoscopic image using polarized glasses or liquid crystal shutter glasses. The glasses-free method generally includes a parallax barrier method and a lenticular method.

In terms of technology, the 3D image can be easily implemented in terms of technology, and the cost can be reduced compared to the lenticular method. However, the barrier method has a disadvantage in that the luminance loss due to the barrier is large. In particular, in the case of an organic light emitting diode (OLED) display device, the driving voltage of the OLED must be increased to compensate for the luminance loss, which shortens the lifespan of the OLED and increases the power consumption. A problem arises. In addition, as the life of the OLED is shortened, afterimages occur when the brightness of the OLED decreases.

The present invention provides a stereoscopic image display device and a driving method thereof capable of increasing luminance when a 3D image is implemented without adjusting a driving voltage.

A stereoscopic image display device includes: a display panel including a first substrate on which pixels and a reflective film are formed, and a second substrate facing the first substrate; A barrier that partially blocks an edge of each of the pixels when a 3D image including a left eye image and a right eye image is displayed on the display panel; And a reflection pattern formed at a portion of the first substrate and the second substrate opposite to the non-light emitting region between the pixels to reflect the light incident from the pixels toward the pixels. In addition to transmitting the light from the pixels, it is characterized in that for reflecting the light reflected by the reflection pattern.

A driving method of a stereoscopic image display device according to an embodiment of the present invention includes a display panel including a first substrate having pixels and a reflective film formed thereon, and a second substrate facing the first substrate. Partially blocking an edge of each of the pixels when a 3D image including a left eye image and a right eye image is displayed; And reflecting the light incident from the pixels toward the pixels, wherein the light is formed at a portion of the first substrate and the second substrate, the portion of the first substrate facing the non-light emitting region between the pixels. It is characterized by transmitting light from the field and at the same time reflecting the light reflected by the reflection pattern.

The present invention forms a reflection pattern for reflecting light generated from pixels on a substrate of a display panel to concentrate light generated from the pixels to an opening of a barrier. As a result, the present invention can increase the luminance of the display panel in the 3D image without adjusting the driving voltage.

Furthermore, the present invention drives the display panel at low power because it is not necessary to increase the driving voltage of the display panel. As a result, the present invention can reduce power consumption, and in the case of an OLED display device, can increase OLED life and improve afterimages.

1 is a diagram illustrating a parallax barrier for implementing a 3D image.
2 is a view illustrating the operation of a switchable barrier in a 2D image.
3 is a view illustrating operation of a switchable barrier in a 3D image.
4 is a diagram illustrating that an OLED display device is formed in a bottom light emitting structure.
5 is a view illustrating that an OLED display device is formed in a top light emitting structure.
6 illustrates an OLED display panel and a barrier according to an exemplary embodiment of the present invention.
7 to 10 are views showing the shape of the reflective pattern according to an embodiment of the present invention.
11 and 12 are views illustrating a region in which a reflection pattern is formed according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Like numbers refer to like elements throughout. In the following description, when it is determined that a detailed description of known functions or configurations related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The display panel 10 of the stereoscopic image display device of the present invention is a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), an organic light emitting display The display device may be implemented as a flat panel display device such as an organic light emitting diode (OLED). Although the present invention has been exemplified with respect to the OLED display device in the following embodiments, it should be noted that the present invention is not limited to the OLED display device.

The names of the components used in the following description are selected in consideration of the ease of preparation of the specification, and may be different from the names of the actual products.

1 is a diagram illustrating a parallax barrier 20 for implementing a 3D image. Referring to FIG. 1, in the parallax barrier 20, a 3D stereoscopic image is realized by dividing a left eye image and a right eye image by selectively blocking light emitted from the display panel 10 using the barrier. However, since the light transmitted from the parallax barrier 20 is less than about 50% of the incident light, there is a disadvantage in that the luminance loss is many. The parallax barrier 20 barrier is formed at a position opposite to the non-light emitting region of each of the RGB pixels, as shown in FIG. 6, to partially block an edge of each of the RGB pixels.

Since the parallax barrier 20 cannot turn on / off the optical separation, only the 3D stereoscopic image can be realized, and there is a problem in that switching between the 2D and 3D images is not possible. Accordingly, a switchable barrier scheme in which two-dimensional and three-dimensional images are compatible has been proposed.

2 and 3 are diagrams illustrating the operation of the switchable barrier 30 in 2D and 3D images. 2 and 3, the switchable barrier 30 may include the first and second transparent substrates 31 and 32, the first and second polarizing plates 33A and 33B, the split electrodes 34A and 34B, The liquid crystal layer 35 and the common electrode 36 are included.

The first and second transparent substrates 31 and 32 of the switchable barrier 30 face each other. The first and second transparent substrates 31 and 32 may be implemented with glass or film. A plurality of split electrodes 34A and 34B are patterned on the first transparent substrate 31. The common electrode 36 is formed of one film on the second transparent substrate 32.

The switchable barrier 30 includes a liquid crystal layer 35 formed between the first and second transparent substrates 31 and 32. The liquid crystal molecules of the liquid crystal layer 35 are rotated by the voltage difference between the common electrode 36 and the divided electrodes 34A and 34B.

As shown in FIG. 2, since a voltage difference does not substantially occur between the common electrode 36 and the split electrodes 34A and 34B of the switchable barrier 30, the liquid crystal molecules do not rotate. Therefore, the light passes through the switchable barrier 30 as it is, and the user sees a two-dimensional image without parallax between left and right eyes.

As shown in FIG. 3, in the 3D image, a voltage difference occurs due to a voltage applied to the common electrode 36 and the split electrodes 34A and 34B of the switchable barrier 30. The voltage applied to the common electrode 36 and the 2n (n is positive) electrodes 34B does not substantially generate a voltage difference, and thus the liquid crystal molecules do not rotate. A voltage difference is generated between the common electrode 36 and the second n-1 electrodes 34A. The liquid crystal molecules between the common electrode 36 and the second n-1 electrodes 34A rotate.

A first polarizing plate 33A is attached to the first transparent substrate 31 of the switchable barrier 30. A second polarizing plate 33B intersecting with the first polarizing plate 33A is attached to the second transparent substrate 32.

The liquid crystal molecules in the region between the common electrode 36 and the second n-electrodes 34B do not rotate. The light passing through the first polarizing plate 33A may pass through the second polarizing plate 33B because the polarization characteristic is changed in the region between the common electrode 36 and the second n electrodes 34B.

The liquid crystal molecules in the region between the common electrode 36 and the second n-1 electrodes 34A rotate. The light passing through the first polarizing plate 33A is blocked by the second polarizing plate 33B since the polarization characteristic does not change in the region between the common electrode 36 and the second n-1 electrodes 34A. Therefore, the region between the common electrode 36 and the 2n-1 electrodes 34A serves as a barrier to block light. A region between the common electrode 36 and the 2n-1 electrodes 34A serving as a barrier is formed at a position opposite to the non-light emitting region of each of the RGB pixels as shown in FIG. 6 to partially cover the edge of each of the RGB pixels. Block partially.

Proceeds to the switcher block the right eye light is the user of the liquid crystal layer 35, right image RGB (RGB _R) due to the area to block the light, as shown in Figure 3 of the barrier 30, and the left image RGB (RGB _L) The light goes to the user's left eye. Therefore, since the left and right eyes of the user can feel parallax, a 3D image is realized.

The display panel 10 of the stereoscopic image display device of the present invention may be implemented as an OLED display device. An active matrix type organic light emitting diode display (AMOLED) displays an image by controlling a current flowing through the OLED using a thin film transistor (hereinafter referred to as a TFT). . The OLED display device displays an image in the form of bottom emission, top emission, or the like according to the structure of the OLED.

4 is a diagram illustrating that an OLED display device is formed in a bottom light emitting structure. Referring to FIG. 4, the OLED display device having the bottom light emitting structure is formed such that the gate electrode 102 is formed on the lower substrate 101, and the source electrode 103 and the drain electrode 104 are in contact with the gate electrode 102. do. The gate electrode 102 is protected by the gate insulating film 105 covering the gate electrode 102. A semiconductor 106 is formed on the gate insulating layer 105, and the semiconductor 106 is positioned between the source electrode 103 and the drain electrode 104. An interlayer insulating film 107 is formed on the semiconductor 106, and a planarization film 108 is formed on the interlayer insulating film. An anode electrode 109 is formed on the planarization film 108, and the anode electrode 109 contacts the source electrode 103 through a contact hole. The anode electrode 109 is in contact with the OLED layer 111, and the portion where the anode electrode 109 is not in contact with the OLED layer 111 is filled with the first insulating layer 110. The cathode electrode 112 is positioned over the OLED layer 111. Since the cathode electrode 112 is formed of a metal cathode electrode 112 thicker than the top emitting structure, the light emitted from the OLED layer to the cathode is reflected toward the anode electrode. The gas injection layer 113 is formed on the cathode electrode 112. On the gas injection layer 113, a transparent protective film 114 may be formed in multiple layers to protect organic materials from moisture and air. The encapsulation substrate 115 is bonded to the gas injection layer 113 and the transparent protective layer 114.

In the bottom emitting structure, light emitted from the OLED layer 111 is emitted to the outside through the lower substrate 101. Therefore, in the case of the back light emitting structure, since the emitted light must pass through the TFTs, capacitors, wirings, etc. constituting the pixels, there is a problem in that the area where light is actually emitted is obscured and the area of the light emitting part is reduced.

In the bottom emission structure, the reflective pattern 117 is formed on the lower substrate 101. Light emitted from the OLED layer is reflected by the reflective pattern 117 or emitted to the outside through the lower substrate 101. Some of the emitted light is blocked by the barrier 116. Detailed description thereof will be described with reference to FIG. 6.

5 is a view illustrating that an OLED display device is formed in a top light emitting structure. Referring to FIG. 5, the OLED display device having the top light emitting structure is formed such that the gate electrode 202 is formed on the lower substrate 201, and the source electrode 203 and the drain electrode 204 are in contact with the gate electrode 202. do. The gate electrode 202 is protected by the gate insulating film 205 covering the gate electrode 202. A semiconductor 206 is formed on the gate insulating film 205, and the semiconductor 206 is positioned between the source electrode 203 and the drain electrode 204. An interlayer insulating film 207 is formed over the semiconductor 206, and a planarization film 208 is formed over the interlayer insulating film. An anode electrode 209 is formed on the planarization film 208, and the anode electrode 209 contacts the source electrode 203 through a contact hole. The anode electrode 209 is in contact with the OLED layer 211, and the portion where the anode electrode 209 is not in contact with the OLED layer 211 is filled with the first insulating layer 210. A cathode electrode 212 is positioned over the OLED layer 211. The cathode electrode 212 is protected by the second insulating film 213. On the second insulating layer, a transparent protective layer 214 may be formed in multiple layers to protect organic materials from moisture and air. The encapsulation substrate 216 is bonded by the sealant 215 over the transparent protective film 214.

In the top emitting structure, light emitted from the OLED layer 111 is emitted to the outside through the encapsulation substrate 216. Accordingly, the front light emitting structure is advantageous in that it has a high aperture ratio, and thus, is advantageous over the bottom light emitting structure in terms of the lifetime of the OLED because there is no portion of the light obscured. In addition, in the case of the front light emitting structure, since the light does not need to be emitted to the anode electrode side, there is an advantage that the lower substrate does not have to be transparent, and a thin substrate may be used.

In the top emitting structure, the reflective pattern 218 is formed on the encapsulation substrate 216. Light emitted from the OLED layer is reflected by the reflective pattern 218 or emitted to the outside through the encapsulation substrate 216. Some of the emitted light is blocked by barrier 217. Detailed description thereof will be described with reference to FIG. 6.

6 illustrates an OLED display panel and a barrier according to an exemplary embodiment of the present invention. The stereoscopic image display device of the present invention includes a display panel 10 and a barrier. The display panel 10 displays an image, and the barrier implements an image from the display panel in three dimensions. The barrier is implemented using the parallax barrier 20 described with reference to FIG. 1 and the switchable barrier 30 described with reference to FIGS. 2 and 3. The display panel 10 has been described in detail with reference to FIGS. 4 and 5.

In the stereoscopic image display apparatus of the present invention, the reflective pattern 11 is formed on a portion of the upper or lower substrate facing the non-light emitting region D of the RGB pixels. 4 and 5, in the case of the OLED display device having the bottom light emitting structure, the reflective pattern 11 is formed on the lower substrate 101, and in the case of the OLED display device having the top light emitting structure, the reflective pattern 11 is the encapsulation substrate. 216 is formed.

3d in order to implement a video RGB pixels are RGB pixels for displaying left-eye image (RGB _L) and RGB pixels displaying the right eye image _(L RGB) are formed alternately. An array of RGB pixels may be formed as shown in FIGS. 11 and 12, which will be described later with reference to FIGS. 11 and 12.

As shown in FIG. 6, the barrier 21 is formed at a position opposite to the non-light emitting region D of each of the RGB pixels. The barrier 21 is formed larger than the non-light emitting area D to partially block a portion of each edge of the RGB pixels. Accordingly, the light generated from the RGB pixels of the display panel is caused by the light 41 reaching the user through the opening not blocked by the barrier 21, the light 42 blocked by the barrier 21, and the reflection pattern. Divided into reflected light 43. The luminance of the display panel is lowered when the 3D image is implemented due to the light 42 blocked by the barrier 21.

The reflection pattern 11 is formed to have left and right symmetry so as to reflect light incident from the left side to the left side and reflect light incident from the right side to the right side. When the light generated from the RGB pixel (RGB _L ) displaying the left eye image is incident on the RGB pixel (RGB _R ) displaying the right eye image, the light of the right eye image and the light of the left eye image are mixed to be displayed by the user's right eye. Can be. In this case, 3D crosstalk may occur in which the left eye image and the right eye image overlap. Therefore, it should be designed so that light incident from the left is not reflected to the right and that incident light from the right is not reflected to the left.

The reflective pattern 11 may be specifically formed as shown in FIGS. 7 to 10. The cross-sectional shape of the reflective pattern 11 may be formed such that the reflective surface of the concave lens form is symmetrical as shown in FIGS. 7 and 8. In addition, the cross-sectional shape of the reflective pattern 11 may be formed such that the linear reflective surface is left-right symmetrical as shown in FIGS. 9 and 10. The reflective pattern 11 of FIG. 9 is shaped like an isosceles triangle, and the reflective pattern 11 of FIG. 10 is shaped like an isosceles trapezoid.

The reflective pattern 11 includes silver (Ag), aluminum (Al), an alloy of silver (Ag) and magnesium (Mg), an alloy of silver (Ag) and aluminum (Al), and silver (Ag) having high reflectance. It may be formed of an alloy of calcium (Ca). As the reflectance of the reflective pattern 11 is higher, more light is reflected by the reflective pattern 11, so that more light is concentrated in the openings not blocked by the barrier. As a result, the luminance of the display panel of the 3D image is increased.

11 and 12 are views illustrating a region in which a reflection pattern is formed according to an embodiment of the present invention. FIG. 11 illustrates a case in which an image is implemented with a long direction (x-axis direction) of the display panel in a horizontal direction, and FIG. 12 illustrates a case in which an image is implemented with a short direction (x-axis direction) of a display panel in a horizontal direction. .

Referring to FIGS. 11 and 12, RGB pixels are repeatedly arranged by using “RGB” as a unit. In FIG. 11, the unidirectional (y-axis direction) width of the R pixel corresponds to W ₁ , the unidirectional (y-axis direction) width of the G pixel corresponds to W ₂ , and the unidirectional (y-axis direction) width of the B pixel corresponds to W ₃ , where W ₃ is the largest and W ₂ is the smallest (W ₃ > W ₁ > W ₂ ). In FIG. 12, the unidirectional (x-axis direction) width of the R pixel is W ₁ , and the unidirectional (x-axis direction) width of the G pixel is W _2, of the B pixel unidirectional (x-axis direction), the width corresponds to W _3, W ₃ is the largest and, W ₂ is the _{smallest. (W 3> W 1>} W 2)

As a result, the opening area of the B pixels has the largest B (Blue) and the smallest G (Green). This is because the luminance contribution of the G (Green) pixel is the largest and the luminance contribution of the B (Blue) pixel is the smallest, and thus the white balance is adjusted by adjusting the opening area of each of the R, G, and B pixels.

In order to realize a 3D image, a barrier is formed at a portion of the upper or lower substrate opposite to the non-light emitting region D of the RGB pixels. Accordingly, the reflective pattern 11 reflects the light from the RGB pixels to be blocked by the barrier and the reflective film 12 reflects the light reflected from the reflective pattern 11 through the reflective pattern 11 to the barrier. More light is emitted into the openings that are not blocked by the opening.

The size of the reflective pattern 11 is smaller than the non-light emitting area D of the RGB pixels. This is because when the size of the reflective pattern 11 is larger than the non-light emitting area D of the RGB pixels, the luminance of the display panel 10 is lowered by blocking light generated from the RGB pixels. On the other hand, as shown in FIG. 12, when the image is implemented with the unidirectional direction (x-axis direction) of the display panel as the horizontal direction, the width of the non-light emitting area D varies depending on the unidirectional (x-axis direction) width of the RGB pixels.

The reflective pattern 11 may have a thickness of about 10 μs to about 3000 μs. When the thickness of the reflective pattern 11 is less than 10 μs, it is difficult to properly perform the role of the reflective pattern, and when the thickness of the reflective pattern 11 exceeds 3000 μs, wet etching and dry etching processes are performed. This makes the implementation difficult and raises the cost.

As shown in FIG. 6, the light 43 reflected by the reflective pattern 11 is reflected by the reflective film 12 again. The reflective film 12 primarily passes light generated from the RGB pixels. The light generated from the RGB pixel passes through the reflective film 12 and then proceeds to the opening 41 without being blocked by the barrier (41), blocked by the barrier (42), or reflected by the reflective pattern (43). The reflective film 12 secondly reflects the light reflected by the reflective pattern again. The light 43 reflected back by the reflective film 12 proceeds to an opening which is blocked by the barrier or not blocked by the barrier.

The reflective film 12 is advantageously formed of a material having high light transmittance as well as high light transmittance. In the case of the organic light emitting diode device having the bottom light emitting structure, the anode electrode 109 becomes the reflective film 12. In this case, the reflective film 12 is made of aluminum (Al), and may have a thickness of 500 kPa to 3000 kPa. In the case of an organic light emitting diode device having a top light emitting structure, the cathode electrode 212 becomes the reflective film 12. In this case, the reflective film 12 is made of silver (Ag) and may have a thickness of 500 kPa to 3000 kPa. If the thickness of the reflecting film 12 is less than 500 mm, the reflecting film 12 transmits light rather than reflecting light, thereby preventing the proper function of the reflecting film 12. If the thickness of the reflective film 12 is greater than 3000 GPa, it is difficult to implement by wet etching and dry etching, resulting in a cost increase.

The display panel may be implemented as one of a liquid crystal display (LCD), a field emission display (FED), a plasma display panel (PDP), and an organic light emitting diode (OLED). When the pixel electrode and / or the common electrode are formed as a translucent electrode in the liquid crystal display device, the same effects as in the above-described embodiment may be provided.

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 present invention should not be limited to the details described in the detailed description, but should be defined by the claims.

10: display panel 11, 117, 218: reflection pattern
12: reflective film 20: parallax barrier
21, 116, 217: barrier 30: switchable barrier
31: first transparent substrate 32: second transparent substrate
33A: first polarizing plate 33B: second polarizing plate
34A, 34B: split electrodes 35: liquid crystal layer
36: common electrode 101, 201: lower substrate
102, 202: gate electrode 103, 303: source electrode
104, 204: drain electrode 105, 205: gate insulating film
106 and 206: semiconductors 107 and 207: interlayer insulating film
108, 208: planarization film 109, 209: anode electrode
110, 210: first insulating film 111, 211: OLED layer
112 and 212, cathode electrode 113, gas injection layer
114 and 214: transparent protective film 115 and 216: encapsulation substrate
213: second insulating film 215: sealant layer

Claims (11)

A display panel including a first substrate on which pixels and a reflective film are formed, and a second substrate facing the first substrate;
A barrier that partially blocks an edge of each of the pixels when a 3D image including a left eye image and a right eye image is displayed on the display panel; And
A reflection pattern formed on a portion of the first substrate and the second substrate opposite to the non-light emitting region between the pixels to reflect light incident from the pixels toward the pixels;
And the reflective film transmits light from the pixels and at the same time reflects light reflected by the reflective pattern. The method of claim 1,
And the barrier propagates the light of the left eye image generated from the pixels to the left eye of the user and the light of the right eye image to the right eye of the user. The method of claim 1,
And the barrier is a switchable barrier that passes light generated from the pixels in a 2D image as it is and partially blocks light generated from the pixels in the 3D image. The method of claim 1,
And the reflection pattern is formed to be symmetrical to reflect light incident from the left side to the left side and reflect light incident from the right side to the right side. The method of claim 1,
And the reflective pattern is formed of any one of aluminum, silver, an alloy of magnesium and silver, an alloy of aluminum and silver, and an alloy of silver and calcium. The method of claim 1,
And a thickness of the reflective pattern is 10 mW to 3000 mW. The stereoscopic image display device of claim 1, wherein a size of the reflective pattern is smaller than a non-light emitting area of the pixels. The method of claim 1,
The display panel of claim 3, wherein the display panel is implemented by any one of a liquid crystal display, a field emission device, a plasma display panel, and an organic light emitting diode device. The method of claim 8,
The reflective film is made of silver in the case of the organic light emitting diode device having a top light emitting structure, the stereoscopic image display device characterized in that the thickness of 500 ~ 3000Å. The method of claim 8,
The reflective film is made of aluminum in the case of the organic light emitting diode device having a back light emitting structure, the stereoscopic image display device characterized in that the thickness of 500 ~ 3000Å. In a stereoscopic image display device comprising a display panel including a first substrate having pixels and a reflective film, and a second substrate facing the first substrate,
Partially blocking an edge of each of the pixels when a 3D image including a left eye image and a right eye image is displayed on the display panel; And
Reflecting light incident from the pixels toward one of the first substrate and the second substrate, wherein the light is formed at a portion of the first substrate and the second substrate opposite the non-light emitting region;
And the reflective film transmits light from the pixels and at the same time reflects light reflected by the reflective pattern.

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