KR101975539B1 - Backlight unit with barrier embedded light guide plate and display device including the same - Google Patents

Abstract

The backlight unit includes a light guide plate and a first light source and a second light source disposed on different sides of the light guide plate, wherein the light guide plate includes a light guide unit for advancing incident light incident from the light source by total internal reflection, And a plurality of inverse prism structures having sidewalls for reflecting a part of the linear prism structure, and a plurality of linear light beams are output through the light guide plate. The display device includes a display panel disposed on the backlight unit.

Description

BACKLIGHT UNIT WITH BARRIER EMBEDDED LIGHT GUIDE PLATE AND DISPLAY DEVICE INCLUDING THE SAME BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit including a barrier-integrated light guide plate, and more particularly, to a backlight unit including a backlight unit including a light guide plate having a barrier function without disposing a lens or a barrier separately, ≪ / RTI >

Techniques for displaying two or more screens on a single screen can be used for non-glasses three-dimensional displays, multi-view (multi-view) displays, and the like. The method of implementing the function may be divided into a time division method and a space division method.

The time division method is a method of changing the position (or angle) of the screen in time sequence so that different screens can be seen depending on the position. This method requires a high-speed display to provide sufficient resolution and greatly limits the number of screens displayed depending on the display speed.

The space division method is a method of displaying different pixels on the screen according to the position of the viewer. In this method, two or more screens are simultaneously displayed on one screen and the directionality of light passing through each pixel of the display panel is independently controlled.

In the case of the space division method, it may be implemented by inserting a microlens or a barrier on the front or rear surface of a screen. However, additional members such as lens arrays or barriers are required. As a result, the thickness of the display device increases and the price increases.

As described above, both the time division method and the space division method have disadvantages. Particularly, the problem becomes more prominent as the number of viewpoints to be implemented increases. Since the time division method divides each frame by the number of viewpoints, it needs to operate at a higher speed as the number of viewpoints increases. For example, to implement a 60 Hz image at four viewpoints, it must operate at 240 Hz. However, since the response speed of the display, that is, the liquid crystal, is limited, it is difficult to transmit an image to a predetermined number or more of viewpoints. In addition, since the space division method divides one screen into a plurality of views, the resolution is reduced in proportion to the number of viewpoints.

Therefore, there is a need for a technique capable of implementing a display capable of three-dimensional (3D) display and / or 2D / 3D conversion without disadvantages of the above-described time division method and space division method and with no additional member disposed Is emerging.

Korean Patent Laid-Open No. 10-2012-0140203 (published on December 28, 2012)

An object of the present invention is to provide a backlight unit including a barrier-integrated light-guide plate.

Another object of the present invention is to provide a display device including the backlight unit.

It should be understood, however, that the present invention is not limited to the above-described embodiments, and may be variously modified without departing from the spirit and scope of the present invention.

In order to accomplish one object of the present invention, a display device according to embodiments of the present invention includes a display panel; A light guide plate disposed under the display panel; And a first light source and a second light source disposed on different side surfaces of the light guide plate, wherein the light guide plate includes: a light guide unit for advancing incident light incident from the light source by total internal reflection; And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion, and a plurality of linear light beams are emitted through the light guiding plate.

In order to achieve another object of the present invention, a backlight unit according to embodiments of the present invention includes a first light source and a second light source disposed on different side surfaces of a light guide plate and the light guide plate, And a light emitting portion having a plurality of inverse prism structures having a light guiding portion for advancing the incident light by total internal reflection and a side wall for reflecting a part of the incident light on the light guiding portion, and a plurality of linear light beams are emitted through the light guiding plate.

According to embodiments of the present invention, a backlight unit including a barrier-integrated light guide plate and a display device including the backlight unit can be provided.

In addition, according to embodiments of the present invention, a barrier-integrated light guide plate can be realized by using the reverse prism structure disposed on the upper portion of the light guide portion.

In addition, according to embodiments of the present invention, it is possible to realize a directional backlight and a display capable of 2D / 3D conversion suitable for the time division mode by adjusting the positions of the light sources disposed at the side of the light guide portion.

In addition, according to embodiments of the present invention, it is possible to provide a technique capable of providing a multi-view image with a simple structure.

In addition, according to embodiments of the present invention, it is possible to provide a backlight unit capable of realizing a three-dimensional display by minimizing disadvantages of a space division method and a time division method. According to the embodiments of the present invention, one frame can be divided into two frames using the time division scheme, and a plurality of frames can be transmitted in different directions every 1/2 frame. Accordingly, a multi-view image can be realized only at a speed twice the liquid crystal operation speed of the normal time division method, with a reduction in resolution by half of the number of viewpoints realized compared with the conventional space division method.

However, the effects of the present invention are not limited to the above effects, and may be variously extended without departing from the spirit and scope of the present invention.

1 is a cross-sectional view for explaining the operation principle of a light guide plate having a reverse prism structure and a display device including the same according to embodiments of the present invention.
FIG. 2 is a diagram illustrating a linear light array implemented through the light guide plate of FIG. 1;
3A is a view showing a reflective surface according to the position of a light source of an inverse prism structure of a light guide plate according to embodiments of the present invention.
FIG. 3B is a simulation result showing the positional shift of the linear light emitted through the light guide plate according to the embodiments of the present invention in accordance with the switching of the light source.
4 is an example of realizing multi-view display using the light guide plate according to the embodiments of the present invention.
FIGS. 5A, 5B, and 5C are graphs illustrating the relationship between the spacing of the inverse prism structure included in the light guide plate for implementing the 3D display and the 2D / 3D conversion display, the sidewall distance of the inverted prism structure, And the pixel width are exemplified.
FIG. 6A illustrates a case where cross-talk between viewpoints occurs in the light guide plate according to the embodiments of the present invention.
FIG. 6B illustrates a structure of a light guide plate according to embodiments of the present invention for preventing crosstalk.
7 illustrates an inverted prism structure included in a light guide plate according to embodiments of the present invention.
8A illustrates the shape and arrangement of the inverse prism structure included in the light guide plate according to the embodiments of the present invention.
8B illustrates the shape and arrangement of light source positions and inverse prism structures for a light guide plate according to embodiments of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

1 is a cross-sectional view for explaining the operation principle of a light guide plate having a reverse prism structure and a display device including the same according to embodiments of the present invention.

1, a display device 1000 according to an embodiment of the present invention includes a display panel 200, a light guide plate 110 disposed below the display panel, and a light source (not shown) disposed on a side surface of the light guide plate 110 120). 1, only one light source is disposed on the left side of the light guide unit 110. However, the light guide unit 110 may include light sources on both sides of the light guide unit 110 according to an embodiment of the present invention.

The light guiding unit 110 can advance the light incident from the light source 120 by total internal reflection. For this, the light guiding portion 110 may include a light transmitting material. For example, the light guiding portion 110 may include a transparent and elastic polydimethylsiloxane.

According to the embodiment, a PMMA (Poly Methyl Methacrylate) plate can be used as a substrate in manufacturing the light guide plate 110 according to the embodiment of the present invention. PMMA plates have high optical properties and are cost-effective. An opaque copper layer can then be formed on the PMMA plate. For example, a copper (Cu) layer may be formed by thermal evaporation. A linear array corresponding to the bottom surface of the inverse prism structure 113 may be patterned through photolithography. A negative tone photoresist can then be coated on the patterned copper layer. For example, the SU-8 material can be spin-coated. Backside diffuser lithography may be performed at a later stage to fabricate a microstructure having stripe-type inclined sidewalls. After developing the photoresist, the remaining copper layer is etched to produce a transparent light guide plate 110 having a linear inverted prism structure (113) array.

The light guide plate 110 includes a light guide portion 111 for advancing the incident light incident from the light source 120 by total internal reflection and a light guiding portion 111 for guiding a part of the incident light on an inclined side wall And a light emitting portion having a plurality of inverse prism structures 113 having a plurality of inverse prism structures S having a plurality of inverse prism structures. A plurality of linear lights can be emitted through the light guide plate 110 according to the embodiment.

In FIG. 1, the light guide plate 110 and the light source 120 including the light guide unit 111 and the reverse prism structure 113 may be combined to constitute the backlight unit 100.

As illustrated in FIG. 1, the light guide plate 110 according to the embodiment of the present invention has an inverted prism structure 113 having an inverted prism sectional shape having an inverted slope on the light guide 111. In the embodiment of the present invention, the shape of the top surface of the inverted prism structure 113 may be variously formed as needed, such as a circular shape and a polygonal shape. This will be described in detail with reference to FIG. 8A.

The light source 120 may be positioned at the end of the light guiding portion 111. The light emitted from the light source 120 may be guided inside the light guiding portion 111 and may be reflected on the side wall S of the reverse prism structure 113 and may exit the light guiding plate 110. At this time, light can be totally reflected from the sidewalls of the inverse prism structure 113, and reflection occurs on the sidewalls of the two sidewalls S of the inverse prism structure 113, which face the light source 120 (dotted line). The outgoing efficiency of each light source located on both sides of the light guiding portion 111 according to the embodiment of the present invention is influenced by the shape of the side wall facing the light source among the two side walls of the inverse prism structure 113. In addition, by controlling the inclination of the sidewalls of the inverse prism structure 113, the directing angle of the light incident from the light sources located at both ends of the light guide unit 111 and output through the inverse prism structure 113 can be adjusted. In the experiment, when the PMMA substrate is used as the light guiding portion 111 and the microstructure of the inverted prism is formed of the SU-8 material, the refractive indexes of the light guiding portion 111 and the inverted prism structure 113 are made to be 1.48 and 1.59, respectively . In this case, in order to increase the light output efficiency, the side light angle of the light guide plate 110 was made to be 57.5 degrees, and vertical light output could be achieved. It is apparent that various refractive indexes and side angles may be required depending on the embodiment and the manufacturing material.

According to the embodiment, the reflector may be formed on the side surface 112 of the opposite end of the light guide 120, In this case, the light impinging on the reflector may be reflected at the side wall of the two sidewalls S of the reverse prism structure 113 facing the side surface 112 on which the reflector is disposed (solid line).

In the embodiment of the present invention, light from the light source 120 is reflected through the side wall S of the reverse prism structure 113 and is output, so that a plurality of linear lights can be realized without a lens or a barrier film .

2 is a diagram illustrating a linear optical array implemented through the light guide plate of FIG.

2 (a) shows an array of inverted prism structures 113 observed through a microscope on the upper surface of the light guide plate 110 in a state where the light source 120 disposed on the side surface of the light guide plate 110 is turned off . As shown in FIG. 2 (a), the inverted prism structure 113 having an inverted trapezoidal cross section whose upper surface is wider than the bottom surface may be configured to extend in the longitudinal direction perpendicular to the cross section. For example, the inverse prism structure 113 may extend from one end of the light guide plate 100 to the opposite end. Accordingly, a linear light source can be realized.

2B illustrates that the linear light source array is emitted from the upper surface of the light guide plate 110 through the light guide plate 110 in a state where the light source 120 disposed on the side surface of the light guide plate 110 is turned on. do.

2 is a top view of the light guide plate. 2, an inverse prism structure 113 having an inverted trapezoidal cross section is disposed at an upper portion of the light guiding portion 111 in such a manner as to be inclined to the side of the upper surface of the light guiding portion 111. For example, in Fig. 2, a plurality of inverse prism structures 113 extend from the lower left end to the upper right direction. Accordingly, it can be seen that the linear light emitted through the light guide plate 110 is also inclined. The inverse prism structure 113 may be formed to extend in parallel to the transverse or longitudinal sides of the light guide plate 100 according to the embodiment.

3A is a view showing a reflective surface according to the position of a light source of an inverse prism structure of a light guide plate according to embodiments of the present invention. 3A, when the light source 121 located on the left side of the inverted prism structure 113 is turned on, the light R incident from the light source is reflected by the light source 121, Directional sidewall S2 and can be output. 3A, when the light source 122 positioned on the right side of the inverse prism structure 113 is turned on, the light R incident from the light source 122 is incident on the side wall (the side opposite to the light source 122) S1) and can be output.

FIG. 3B is a simulation result showing a position shift of linear light output through the light guide plate according to the embodiments of the present invention in accordance with the switching of the light source.

3B, the light guide plate 110 includes an inverted prism structure 113, and the first light source 121 and the second light source 122 are disposed at both ends of the light guide plate 110.

The position of the light output through the light guide plate 110 is simulated when the first light source 121 turns off and the second light source 122 is turned on at the leftmost side of FIG. As can be seen, light is emitted only through the first sidewall S1 of the reverse prism structure 113 facing the second light source 122.

The position of light output through the light guide plate 110 is simulated when the first light source 121 is turned on and the second light source 122 is turned off on the rightmost side of FIG. 3b. As shown in the figure, it can be seen that light is emitted only through the second sidewall S2 of the reverse prism structure 113 opposed to the first light source 121. [ Accordingly, it can be seen that the position of the linear light source emitted from the leftmost side of FIG. 3B shifts to the right.

The position of light output through the light guide plate 110 is simulated when both the first light source 121 and the second light source 122 are turned on at the center of FIG. 3B. The first sidewall S1 of the inverted prism structure 113 facing the second light source 122 and the second sidewall S2 of the inverted prism structure 113 opposed to the first light source 121, It can be seen that light is emitted through the light source.

As shown in FIGS. 3A and 3B, light is only emitted through the sidewalls of the inverse prism structure 113, so that discrete linear light for spatially modulated images, without a conventional parallax barrier, An array can be achieved. This makes it possible to maintain the transparency of the backlight unit 100 while still simplifying the entire system. Since the light is emitted only through the sidewall of the inverse prism structure 113 facing the light source, the outgoing light position can be changed by switching the time at which the two light sources are turned on. The backlight unit 100 including the light guide plate 110 shown in FIGS. 3A and 3B can realize a three-dimensional display of a space division type without any additional member such as a barrier or a lens.

4 is an example of realizing multi-view display using the light guide plate according to the embodiments of the present invention. FIG. 4 illustrates a spatial division type multi-view (for example, four view) display using a light guide plate according to embodiments of the present invention. 4 is a conceptual diagram in which four viewpoints are implemented according to the space division method. In order for the viewer to feel the stereoscopic effect through the displayed screen, the left and right eyes of the viewer should be able to see different images. The spatial division type three-dimensional display is designed so that different pixels are seen according to the viewing direction. For example, when the display panel 200 of FIG. 4 is viewed from the left, it is possible to design the pixels indicated by the view 1 (View 1) to be visible and the pixels indicated by the view 4 (View 4) to be viewed when viewed from the right.

When the display panel 200 is a liquid crystal display, light incident from the backlight unit 100 through the color filter located above the liquid crystal is visible to the viewer. 4, the viewer sees a linear light source positioned behind the display panel 200. [ Therefore, when the light sources are arranged discontinuously as shown in FIG. 4, only a specific pixel of the display panel 200 is visible in a specific direction. For example, light passing through view 4 is directed to the right and not visible from the left. If the left and right eyes of the viewer see the pixels indicated by the views 1 and 4, respectively, the viewer can see different images simultaneously through the display panel 200, so that the user can feel a stereoscopic feeling.

At this time, the multi-view display can be implemented in various ways. 5A to 5C, some embodiments will be described.

FIGS. 5A, 5B, and 5C are graphs illustrating the relationship between the spacing of the inverse prism structure included in the light guide plate for implementing the 3D display and the 2D / 3D conversion display, the sidewall distance of the inverted prism structure, And the pixel width are exemplified.

The distance L1 between the opposite sidewalls of the inverted prism structure 113 is defined such that when the inverted prism structure 113 is viewed from above, the distance between the base of the sidewall S1 and S2 It may be a distance connected to each other.

When the display panel 200 is a liquid crystal display, each pixel of the liquid crystal display is divided into three sub-pixels (or four sub-pixels R, G, G, and B representing R, G, ). In the pixel interval and the pixel width defined in the embodiment of the present invention, a pixel means a subpixel. Hereinafter, the pixel interval refers to the distance between the centers of the respective subpixels, and the pixel width refers to the width of the subpixel. According to the embodiment, the pixel interval and the pixel width may not be equal to each other, for example, because a conductive line is disposed between subpixels. Further, the pixel interval and the pixel width may be the same according to the embodiment.

Further, in the embodiment of the present invention, the width, width, and spacing can be measured with respect to the horizontal direction in the cross-sectional view as illustrated in FIG. 5A.

5A, the interval L2 between two adjacent inverse prism structures of the plurality of inverse prism structures 113 according to the embodiment of the present invention is twice as large as the pixel interval L4 of the display panel 200 And the distance L1 between both side walls of the inverse prism structure 113 may be configured to be the same as the pixel width L3 of the display panel. At this time, the first light source 121 and the second light source 122 may be disposed on both ends of the light guide plate 110 at a distance from each other. With this configuration, it is possible to manufacture a 3D backlight unit of a spatial division type having two view points and a backlight unit capable of 2D / 3D conversion without additional members. 5A, the period of the inverse prism structure 113 is set to twice the liquid crystal pixel interval L4, and the distance L1 between the both side walls of the inverse prism structure 113 is set to be the pixel width And the light source is disposed on both sides of the light guide plate 110, it is possible to realize a 2D / 3D conversion display while implementing a space division 3D display having two viewpoints without additional members.

Here, one of the first light source 121 and the second light source 122 may be a 2D light source and the other may be a 3D light source. The 3D light source may be a multi-wavelength light source having a plurality of wavelengths.

For example, the display apparatus 1000 may be configured to operate as a 2D display when the first light source and the second light source are turned on, and to operate as a 3D display when only one of the first light source and the second light source is turned on . At this time, the light source turned on may be the second light source 122 which is a 3D light source.

5A, only the second light source 122, which is a 3D light source, is turned on and the first light source 121 is turned off. In this case, the light guide plate 110 according to the embodiment of the present invention operates as a barrier-integrated light guide plate. 5A, the light from the second light source 122 which is a 3D light source is reflected at the first view View 1 and the second view View 2 when it is reflected at the side wall S 1 of the inverted prism structure 133 Both can be reflected to be implemented.

5A, when displaying a general 2D image, both the first light source 121 and the second light source 122 can be turned on. In this case, since the light passing through each pixel spreads in all directions, a normal 2D image can be output. This is because light is totally reflected from the two side walls S1 and S2.

Generally, not all contents are produced in 3D, so a device capable of operating as a 3D display must also be able to represent 2D media. Although a 2D screen can be displayed if the same screen is transmitted every time the 3D display capable of expressing the multi-viewpoint, the 3D display has problems such as resolution degradation (space division method) and / or brightness degradation (time division method) , It is generally necessary to have additional members suitable for transmitting a high-quality 2D image. A 2D / 3D conversion function is implemented by placing a backlight unit for 2D on the front surface or rear surface of a light guide plate for 3D or using a lens or barrier capable of on / off. Both of these methods have a problem in that the structure of the system is complicated and the cost is increased. However, when the structure according to the embodiment of the present invention as illustrated in FIG. 5A is used, a backlight capable of 2D / 3D conversion according to the operation form of the light sources 121 and 122 disposed on the left and right of the light guide plate 110, Unit 100 and a display apparatus 1000 including the same. In the case of the structure illustrated in FIG. 5A, two views may be formed in the 3D display implementation.

5B and 5C, the interval L2 between two adjacent inverse prism structures among the plurality of inverse prism structures may be the same as the pixel interval L4 of the display panel 200. [ At this time, the first light source 121 and the second light source 122 may be disposed on both ends of the light guide plate 110 at a distance from each other. The side angle? Of the inverse prism structure 113 with respect to the upper surface of the light guiding portion 111 can be configured differently from the angle for vertical outgoing light.

The side angle? Refers to the angle formed by the side wall S of the inverted prism structure 113 with the upper surface of the light guiding portion 110.

With this configuration, a time-division-type display capable of 2D / 3D conversion can be produced. At this time, two images can be implemented by switching the turn-on times of the first light source 121 and the second light source 122 at a high speed in order to implement a multi-view image. In order to realize a 2D image, both the first light source 121 and the second light source 122 may be turned on.

That is, the display device is a display device in which the first light source 121 and the second light source 122 are turned on to operate as a 2D display and alternately turn on the first light source 121 and the second light source 122, Lt; / RTI >

5B shows a case where the side angle θ is larger than an angle for vertical outgoing through the side wall S of the inverted prism structure 113. In FIG. 5C, the side angle θ is larger than the angle for vertical outgoing through the sidewall S of the inverted prism structure 113, Lt; / RTI > is smaller than the angle for vertically emerging through the light source S in FIG.

In order for the viewer to feel the stereoscopic effect through the screen transmitted from the 2D plane, the binocular parallax should be used. That is, the left and right eyes must be different from each other so that they can feel the stereoscopic effect. Each of these screens is referred to as a viewpoint. At least two viewpoints are required to make such a binocular disparity. In this case, only one of the two viewpoints may be formed on each of the left and right sides of the center axis of the display panel 200 according to the structure of the display device, and the two views may be alternately and repeatedly displayed depending on the viewing position. In case of the former, it is impossible to feel a stereoscopic effect if it is deviated from the front of the display panel 200, so that it is difficult for a plurality of people to enjoy the 3D screen at the same time. In the latter case, there is a problem that the left / right screen may be reversed depending on the viewer's position. In order to solve this problem, according to the embodiment, it is preferable to form a large number of viewpoints so that different screens can be viewed according to the viewpoints. When a multi-view 3D display is implemented, different images can be viewed in a three-dimensional manner depending on the viewer's position. For example, when the viewer looks at the display panel 200 at a position where the viewer is bent at the center, the viewer can feel an object in the screen from the side, so that even when several people view the screen at different positions simultaneously, .

5A, the period of the reverse prism structure 113 of the light guide plate 110 is set to be equal to the liquid crystal pixel interval L4 of the display panel 200, and the interval between the both side walls of the reverse prism structure 113 The backlight unit of the time division type is turned on by alternately turning on the first light source 121 and the second light source 122 disposed on both sides of the light guide plate 110, Can be implemented. Here, both the first light source 121 and the second light source 122 may be a 2D light source. When the first light source 121 is turned on and the second view is visible and the second light source 122 is turned on, Lt; / RTI > More specifically, the interval L2 between the inverse prism structures 113 is made equal to the pixel interval L4, and the distance L1 between the both side walls of the inverse prism structure 113 is set to be equal to the pixel width L3 Division type backlight unit can be realized by alternately turning on the first light source 121 and the second light source 122 in synchronization with the liquid crystal of the display panel 200. [

In addition, in the above-described embodiment, the 2D / 3D conversion function may not be implemented. In this case, it is possible to realize a time division / space division hybrid type display in which three or more viewpoints are realized by making the interval L2 between the inverse prism structures 113 larger than the interval L4 of pixels. Specifically, according to the embodiment of the present invention, one frame of the display panel 200 can be divided into two by using the time division method, and a plurality of screens can be transmitted in different directions every 1/2 frame. Accordingly, a multi-view image can be realized only at a speed twice the liquid crystal operation speed of the normal time division method, with a reduction in resolution by half of the number of viewpoints realized compared with the conventional space division method.

5A, the period of the inverse prism structure 113 of the light guide plate 110 is set to n times the liquid crystal pixel interval (L4) of the display panel 200 (where n is a natural number greater than 1) The distance L1 between both side walls of the prism structure 113 is set to n / 2 times the pixel width L3 and the first light source 121 and the second light source 122 are provided at both ends of the light guide plate 110, A 3D backlight unit 100 of a hybrid system in which a time division system and a space division system are combined can be implemented without additional members. In this case, n view points can be formed. According to the embodiment of the present invention the resolution can be doubled as compared with the conventional spatial division method for forming the n viewpoints. According to the embodiment of the present invention, compared with the conventional time division method for forming n viewpoints, The speed can be implemented as 2 / n.

In addition, according to the embodiment, in the hybrid type display, a normal backlight (not shown) may be disposed below the light guide plate 110 having the inverted prism structure 113 to be used as a backlight for a 2D image. Here, the normal backlight may be implemented as a light guide plate having no inverted prism structure 113. In this case, in order to implement a multi-view image, the light guide plate 110 according to the embodiment of the present invention is operated as described above, and a lower backlight can be operated in a conventional manner to implement a 2D image. This is possible because the scattering of the inverse prism structure 113 according to the embodiment of the present invention is small and the inverse prism structure 113 is transparent.

FIG. 6A illustrates a case where cross-talk between viewpoints occurs in the light guide plate according to the embodiments of the present invention.

In an embodiment of the present invention, light incident from the light source 120 is emitted as R1 through the inverse prism structure 113. [ 6A, a part of the light guided into the light guide unit 111 in the light source 120 is reflected by the other end side surface 112 of the light guide unit 111 and is guided into the light guide unit 111 Back light can be output through the inverse prism structure 113 or noise light emitted from the outside through the side surface 112 can be emitted. In this case, the ray is denoted by R2. However, this unintended light can cause interference between viewpoints.

FIG. 6B illustrates a structure of a light guide plate according to embodiments of the present invention for preventing crosstalk.

In order to solve the interference problem between the viewpoints, in the embodiment of the present invention, as shown in FIG. 6B, light is emitted from the light guide part 111 to the side of the light guide part corresponding to the other end of the light guide part 111, Absorbing material 114 may be coated. 6B, the light R2 reaching the light absorbing material 114 is absorbed by the light absorbing material 114 without being emitted through the reverse prism structure 113, so that interference is prevented. ,

7 illustrates an inverted prism structure included in a light guide plate according to embodiments of the present invention. 7, the top width W1 of the inverted prism structure refers to the length of the top surface in the cross section of the inverted prism structure 113. As shown in FIG. That is, the length of the long side of the opposite side of the rectangle in the trapezoidal cross section of the inverted prism structure 113. The width W2 of the side angle of the inverse prism structure 113 refers to the length of the base side where the side wall S of the inverse prism structure 113 is tilted. That is, a value obtained by taking the cosine as the side angle? At the length of the side wall S (W2 = the length of the side wall * cos (?)).

The upper surface width W2 of the side angle of the inverted prism structure 113 is set smaller than the pixel width L3 of the display panel 200 in order to reduce cross- .

In addition, in the embodiment of the present invention, in order to reduce cross-talk and improve the light uniformity between the respective viewpoints, the top width W1 of the inverted prism structure 113 is set to be larger than the pixel width And the first light source and the second light source are disposed at both ends of the light guiding portion 111 so that both reflective surfaces of the inverse prism structure 113 can be designed and utilized as a single linear light source.

8A illustrates the shape and arrangement of the inverse prism structure included in the light guide plate according to the embodiments of the present invention.

8A, the inverse prism structure 113-1 of the light guide plate 110 according to the embodiment of the present invention may be inclined in the horizontal or vertical direction have. For example, the upper surface of the light guiding portion 111 may have a rectangular shape, and the longitudinal direction of the inverted prism structure 113-1 may be disposed in parallel to any of the four sides of the rectangular shape. For example, in FIG. 8A, the horizontal direction may be represented by the X-axis and the vertical direction may be represented by the Y-axis, and the inverted prism structure 113-1 may extend in the X-axis direction and the Y-axis direction.

According to the embodiment, the top surface shape of the side walls S1-2 and S2-2 of the inverted prism structure 113, such as the inverted prism structure 113-2 shown on the right side of FIG. 8A, May be formed to have a curvature instead of a straight line. At this time, the curvature length L5 and the curvature width W3 may be smaller than the width L3 of the pixel of the display panel, thereby reducing interference between the viewpoints. Depending on the embodiment, the width of curvature W3 may correspond to the top width W2 of the side angle of the inverted prism structure 113. [ Here, the bending width W3 is the distance between the outermost point and the innermost point of the curved side surface of the inverted prism structure 113. [ 8B illustrates the shape and arrangement of light source positions and inverse prism structures for a light guide plate according to embodiments of the present invention.

As illustrated in FIG. 8B, the upper surface of the light guiding portion may be formed in a rectangular shape, and the reverse prism structure may be disposed so as not to be parallel to the sides forming the rectangle. At this time, the light source may include a first light source 121 and a second light source 122 arranged at right angles to each other corresponding to two adjacent sides of the rectangle. Light absorbing materials 114-1 and 114-2 may be coated at right angles to two sides of the first light source 121 and the second light source 122, respectively, in order to reduce inter-view interference. That is, the light absorbing material may be coated on the sides of the light guide portion corresponding to the two adjacent sides of the rectangle.

The present invention can be variously applied to an illumination or display device having a light guide plate. For example, the present invention may be applied to a computer, a notebook, a digital camera, a video camcorder, a mobile phone, a smart phone, a smart pad, a PMP, a PDA, an MP3 player, A motion detection system, an image stabilization system, and the like.

Although the light guide plate and the backlight unit according to the embodiments of the present invention have been described above with reference to the drawings, the above description is illustrative and not restrictive insofar as they do not depart from the technical spirit of the present invention. And the like.

1000: Display device
100: Backlight unit
110: light guide plate
111: light-
112: side
113: reverse prism structure
114: Light absorbing material
120, 121, 122: light source

Claims (24)

A display panel;
A light guide plate disposed under the display panel; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
The upper surface of the light guide portion is formed in a rectangular shape,
Wherein the inverse prism structure is arranged not parallel to the side of the rectangle,
Wherein the first light source and the second light source are disposed at right angles to each other corresponding to two adjacent sides of the rectangle,
Wherein light absorbing material is coated on a side surface of the light guiding portion corresponding to two adjacent sides of the rectangle opposite to the first light source and the second light source,
Display device. The method according to claim 1,
The first light source is turned off for the first case in which the first light source is turned on and the second light source is turned off and the position of the linear light emitted through the light guide plate in the second case in which the second light source is turned on is Shifted,
Display device. A display panel;
A light guide plate disposed under the display panel; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
Wherein a distance between two adjacent inverse prism structures of the plurality of inverse prism structures is two times the pixel interval of the display panel and a distance between both side walls of the inverse prism structure is equal to a pixel width of the display panel,
Display device. The method according to claim 1 or 3,
Wherein the display device is configured such that the first light source and the second light source are turned on to operate as a 2D display and only one of the first light source and the second light source is turned on to operate as a 3D display,
Display device. A display panel;
A light guide plate disposed under the display panel; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
Wherein an interval between two adjacent inverse prism structures of the plurality of inverse prism structures is equal to a pixel interval of the display panel,
Wherein a side angle of the inverted prism structure with respect to an upper surface of the light guide unit is different from an angle for vertical exit,
Display device. 6. The method according to claim 1 or 5,
Wherein the display device is configured to operate as a 3D display by alternately switching on and off of the first light source and the second light source, the first light source and the second light source being turned on and acting as a 2D display,
Display device. A display panel;
A light guide plate disposed under the display panel; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
Wherein an interval between two adjacent inverse prism structures of the plurality of inverse prism structures is n times (n is a natural number equal to or larger than 2) the pixel interval of the display panel, and a distance between both side walls of the inverse prism structure is Lt; RTI ID = 0.0 > n / 2 &
Display device. 6. The method according to claim 1 or 5,
Wherein the display device can operate as a hybrid type 3D display in which a time division method and a space division method are combined. A display panel;
A light guide plate disposed under the display panel; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
Wherein an upper surface width of a side angle of the inverse prism structure is smaller than a pixel width of the display panel,
Display device. A display panel;
A light guide plate disposed under the display panel; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
Wherein an upper surface width of the inverse prism structure is smaller than a pixel width included in the display panel,
Wherein the first light source and the second light source are disposed at opposite ends of the light guide portion,
Display device. delete A display panel;
A light guide plate disposed under the display panel; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
Wherein the top surface shape of the sidewall of the inverted prism structure is formed to have a curvature. A light guide plate; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
The upper surface of the light guide portion is formed in a rectangular shape,
Wherein the inverse prism structure is arranged not parallel to the side of the rectangle,
Wherein the first light source and the second light source are disposed at right angles to each other corresponding to two adjacent sides of the rectangle,
Wherein light absorbing material is coated on a side surface of the light guiding portion corresponding to two adjacent sides of the rectangle opposite to the first light source and the second light source,
Backlight unit. 14. The method of claim 13,
The first light source is turned off for the first case in which the first light source is turned on and the second light source is turned off and the position of the linear light emitted through the light guide plate in the second case in which the second light source is turned on is Shifted,
Backlight unit. A light guide plate; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
Wherein a distance between two adjacent inverse prism structures of the plurality of inverse prism structures is twice a pixel interval of a display panel disposed on an upper portion of the light guide plate and a distance between both side walls of the inverse prism structure is equal to a pixel width of the display panel Lt; / RTI >
Backlight unit. 16. The method according to claim 13 or 15,
The display device including the backlight unit may be configured such that the first light source and the second light source are turned on and operate as a 2D display and only one of the first light source and the second light source is turned on to operate as a 3D display ,
Backlight unit. A light guide plate; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
Wherein a distance between two adjacent inverse prism structures of the plurality of inverse prism structures is equal to a pixel interval of a display panel disposed on the light guide plate,
Wherein a side angle of the inverted prism structure with respect to an upper surface of the light guide unit is different from an angle for vertical exit,
Backlight unit. The method according to claim 13 or 17,
The display device including the backlight unit may be configured so that the first light source and the second light source are turned on to operate as a 2D display and alternately turn on the first light source and the second light source to operate as a 3D display Can,
Backlight unit. A light guide plate; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
Wherein a distance between two adjacent inverse prism structures of the plurality of inverse prism structures is n times (n is a natural number of 2 or more) of pixel intervals of a display panel disposed on an upper portion of the light guide plate, Of the pixel width of the display panel,
Backlight unit. 20. The method of claim 19,
Wherein the display device including the backlight unit is capable of operating as a hybrid type 3D display combined with a time division mode and a space division mode. A light guide plate; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
Wherein an upper surface width of a side angle of the inverted prism structure is smaller than a pixel width of a display panel disposed on an upper portion of the light guide plate,
Backlight unit. A light guide plate; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
Wherein an upper surface width of the inverted prism structure is smaller than a pixel width of a display panel disposed on an upper portion of the light guide plate,
Wherein the first light source and the second light source are disposed at opposite ends of the light guide portion,
Backlight unit. delete A light guide plate; And
And a first light source and a second light source disposed on different sides of the light guide plate,
The light guide plate includes:
A light guide unit for advancing the incident light incident from the first and second light sources by total internal reflection; And
And a light emitting portion having a plurality of inverse prism structures having side walls for reflecting a part of the incident light on the light guiding portion,
A plurality of linear light beams are output through the light guide plate,
Wherein a top surface shape of the sidewall of the inverted prism structure is formed to have a curvature.

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