KR102349594B1 - Backlight unit and image display device using the same - Google Patents

Abstract

The present invention provides an image panel, a three-dimensional light guide plate disposed under the image panel and having a plurality of light exit patterns on a lower surface thereof, a flat light guide plate provided under the three-dimensional light guide plate, and side surfaces of the three-dimensional light guide plate and the flat light guide plate, respectively Provided is an image display device including a first light source and a second light source disposed and selectively driven.

Description

A backlight unit and an image display device using the same

The present invention relates to a display device, and more particularly, to a backlight unit capable of selectively realizing a flat image and a stereoscopic image, and an image display device using the same.

Recently, an image display device capable of displaying a three-dimensional image has emerged according to the development of technology related to the image display device and the desire of consumers.

A stereoscopic image display device has been introduced to a method of allowing a stereoscopic effect of an image to be felt by using binocular parallax. For example, a technique for wearing glasses for realizing a three-dimensional effect and a method for realizing a three-dimensional effect without wearing glasses have been known.

The three-dimensional effect by wearing glasses is an anaglyph method in which blue and red sunglasses are worn in both eyes, a polarization method in which glasses of different polarization are worn in both eyes, and time-divided polarization. A time-division method in which spectacles with polarization shutters that are periodically repeated and synchronized with the cycle are worn are known.

However, the method of realizing a three-dimensional effect using glasses has problems such as inconvenience of wearing glasses, and difficulty in observing objects other than images while wearing glasses.

In recent years, in order to solve this problem, various methods for realizing a three-dimensional effect without wearing glasses have been developed.

Representative methods of realizing a three-dimensional effect without wearing glasses include a method using a lenticular lens and a parallax barrier method using a mask having a slit formed therein.

According to a stereoscopic image implementation method using a lenticular lens, a lenticular lens is disposed between an image panel and a light source, and the lenticular lens modulates the path of light emitted from the light source to be irradiated to the image panel.

As the light path is modulated by the lenticular lens, the path of light reaching both eyes of the observer is changed, and accordingly, the pixel area of the liquid crystal panel visible to both eyes of the observer is slightly changed.

The observer's brain feels a stereoscopic (3D) image due to such a subtle difference in the pixel area visible to both eyes of the observer.

Meanwhile, according to the parasitic barrier method, a mask in which transparent slits and opaque slits are repeatedly formed is disposed in front of the image panel. The observer sees the image displayed on the image panel through the transparent slit of the mask. At this time, the observer's left and right eyes see different areas of the image panel, respectively, even through the same transparent slit. The observer's brain feels a three-dimensional image due to the minute difference between the areas visible to both eyes of the observer.

However, a conventional stereoscopic image display device that implements a stereoscopic image without wearing glasses can only display a stereoscopic image, but has difficulty in displaying a flat image.

Recently, a switching 3D display technology capable of converting a 2D flat image and a 3D stereoscopic image has been proposed. Representative implementation methods of this switching 3D display technology include a polarized lens method and a 1-cell active lens. method can be found.

Among these methods, the polarization lens method operates by switching the linear polarization direction by the polarization transmission axis on the image panel through the polarization control cell, and the refractive index difference (Δn) of the RM lens according to each linear polarization direction. It refers to a method in which the presence or absence of a lens effect is determined by , so that the planar mode and the stereoscopic mode are selectively operated.

In addition, the one-cell active lens method has a structure in which a liquid crystal cell having a lens-shaped cavity is attached to the upper side of the image panel, and the refractive index anisotropy (Δn) depending on whether a voltage is applied to the liquid crystal cell. ) means a method to show the presence or absence of a lens effect.

However, as a problem of the conventional switching 3D display technology capable of switching between a flat image and a stereoscopic image, there is a problem of high material cost and deterioration of flat-panel (2D) image quality for implementing the technology.

In particular, the above-mentioned conventional switching 3D display structure basically requires a separate additional liquid crystal cell and some polymerizable lens layer for controlling the polarization in a manner using the polarization properties of liquid crystal.

Therefore, the problem of increasing costs due to the manufacture and attachment of such liquid crystal cells is an important issue in the commercialization of these technologies, but fundamentally, it is not easy to solve by using the polarization characteristics of liquid crystals.

And, in the case of the switching 3D display structure being studied so far, substrates that serve as an optical filter for view division, for example, parts such as an RM lens or a polarization control film, are the top layer of the display screen. Since it is attached to the plane mode, there is a problem of image quality deterioration due to the attached optical filter when switching the plane mode.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a backlight unit capable of selectively realizing a flat image and a stereoscopic image without deterioration of image quality, and an image display device using the same.

Another object of the present invention is to provide a backlight unit capable of adjusting the viewing distance of a stereoscopic (3D) image by driving each light guide plate according to the viewing distance environment of a display user, and an image display device using the same.

Another object of the present invention is to provide a backlight unit capable of improving the quality of a stereoscopic (3D) image in a stereoscopic image display device by blocking light leaking under the stereoscopic light guide plate, and an image display device using the same.

In order to solve the above problems, in one aspect, the present invention provides a three-dimensional light guide plate having a plurality of light exit patterns on a lower surface, a flat light guide plate provided under the three-dimensional light guide plate, and one side of each of the three-dimensional light guide plate and the flat light guide plate By providing a backlight unit for an image display device including a first light source and a second light source that are provided correspondingly and selectively driven, a stereoscopic image and a planar image can be selectively implemented.

The first light source may be driven when a stereoscopic image is implemented through the stereoscopic light guide plate, and the second light source may be driven when a flat image is realized through the flat light guide plate.

The three-dimensional light guide plate may include at least one light guide plate.

In another aspect, the present invention corresponds to a three-dimensional light guide plate provided under an image panel and having a plurality of light exit patterns on the lower surface, a flat light guide plate provided under the three-dimensional light guide plate, and one side of each of the three-dimensional light guide plate and the flat light guide plate By providing an image display device including a first light source and a second light source that is provided and selectively driven, a stereoscopic image and a planar image can be selectively implemented.

The three-dimensional light guide plate may include at least one light guide plate.

When the three-dimensional light guide plate is composed of first, second, and third three-dimensional light guide plates stacked up and down, when the viewing distance of the user when the first three-dimensional light guide plate is driven is D1, the user when the second three-dimensional light guide plate is driven The viewing distance D2 may have a value of D1×2, and the viewing distance D3 of the user when the third stereoscopic light guide plate is driven may have a value of D1×3.

In another aspect, the present invention provides a three-dimensional light guide plate having a plurality of light exit patterns on a lower surface, a flat light guide plate provided under the three-dimensional light guide plate, a light blocking film interposed between the three-dimensional light guide plate and the flat light guide plate, and the three-dimensional light guide plate and A three-dimensional image and a planar image can be selectively implemented by providing a backlight unit for an image display device including a first light source and a second light source that are provided to correspond to one side of each of the flat light guide plates and are selectively driven.

And, in another aspect, the present invention provides a three-dimensional light guide plate provided under the image panel and having a plurality of light exit patterns on the lower surface, a light blocking film provided under the three-dimensional light guide plate, and a flat surface provided under the light blocking film By providing an image display device including a light guide plate and a first light source and a second light source disposed to correspond to one side of each of the three-dimensional light guide plate and the flat light guide plate and selectively driven, a stereoscopic image and a planar image can be selectively implemented.

In another aspect, the present invention provides a three-dimensional light guide plate having a plurality of light exit patterns on a lower surface thereof, a barrier film provided under the three-dimensional light guide plate and having a plurality of light blocking patterns, a flat light guide plate provided under the barrier film, and By providing a backlight unit for an image display device including a first light source and a second light source that are provided to correspond to one side of each of the three-dimensional light guide plate and the flat light guide plate and are selectively driven, a three-dimensional image and a flat image can be selectively implemented.

The light blocking pattern of the barrier film may be disposed at a position corresponding to the light outgoing pattern.

In another aspect, the present invention is provided under the image panel. A three-dimensional light guide plate having a plurality of light exit patterns on its lower surface, a barrier film provided under the three-dimensional light guide plate and having a plurality of light blocking patterns, a flat light guide plate provided under the barrier film, and one of each of the three-dimensional light guide plate and the flat light guide plate By providing an image display device including a first light source and a second light source that is provided to correspond to the side and selectively driven, a stereoscopic image and a planar image can be selectively implemented.

The light blocking pattern of the barrier film may be disposed at a position corresponding to the light outgoing pattern.

In another aspect, the present invention provides a three-dimensional light guide plate having a plurality of light exit patterns on a lower surface, a light blocking film provided inside the light output pattern, a flat light guide plate provided under the three-dimensional light guide plate, and each of the three-dimensional light guide plate and the flat light guide plate By providing a backlight unit for an image display device including a first light source and a second light source that is provided to correspond to one side and selectively driven, a stereoscopic image and a planar image can be selectively implemented.

The light blocking layer may be formed on an inner surface of the light exit pattern or may be embedded in the entire interior of the light exit pattern.

In another aspect, a three-dimensional light guide plate provided under the image panel and having a plurality of light exit patterns on a lower surface thereof, a light blocking film provided inside the light exit pattern, a flat light guide plate provided under the three-dimensional light guide plate, and the three-dimensional light guide plate and a flat surface It is possible to provide an image display device including a first light source and a second light source provided to correspond to one side of each light guide plate and selectively driven.

The light blocking layer may be formed on the inner surface of the light exit pattern or may be embedded in the entire interior of the light exit pattern.

The backlight unit and the image display device using the backlight unit according to the present invention enable the realization of a flat image and a stereoscopic image by selectively driving two light guide plates having a low cost and a simple structure.

In addition, since the backlight unit and the image display device using the same according to the present invention are not controlled using a polarization component as in the prior art for realization of a planar (2D) image and a stereoscopic (3D) image, a separate polarizing material, for example For example, parts such as an RM lens or a polarization control film become unnecessary.

In addition, since the backlight unit and the image display device using the same according to the present invention have a structure in which light guide plates serving as optical filters are disposed on the rear surface, substrates serving as an optical filter for view division are used in the prior art. Since it is attached to the uppermost layer of the display screen, image quality deterioration caused by the attached optical filter when the plane (2D) mode is switched is eliminated.

Furthermore, the backlight unit and the image display device using the same according to the present invention are designed to stack a plurality of three-dimensional light guide plates that affect the viewing distance of a stereoscopic image (3D) so that each light guide plate is driven according to the viewing distance environment of the display user. It is possible to adjust the viewing distance of stereoscopic (3D) images.

The image display device using the backlight unit according to the present invention can reduce leakage light by arranging a shading film having a specific transmittance under the stereoscopic light guide plate. can improve In particular, as the light blocking effect due to non-patterning increases due to a decrease in light leaking from the stereoscopic light guide plate to the flat light guide plate, the crosstalk of the stereoscopic image is greatly reduced, thereby improving the quality of the stereoscopic image. can be

In the image display device using the backlight unit according to the present invention, a barrier film is disposed under the three-dimensional light guide plate so that the light blocking pattern formed on the barrier film is at a position corresponding to the light output pattern of the three-dimensional light guide plate. Since light leaking from the light guide plate toward the optical sheet is physically blocked or reduced by the light blocking pattern of the barrier film, cross-talk (CT) of a stereoscopic image can be greatly improved.

In the image display device using the backlight unit according to the present invention, a light blocking film is formed on the outer surface of the light exit pattern under the three-dimensional light guide plate, so that the light leaking from the stereo light guide plate toward the optical sheet through the light exit pattern is physically blocked or By being reduced, it is possible to greatly improve cross-talk (CT) of a stereoscopic image.

1 is an exploded perspective view schematically showing an image display device according to a first embodiment of the present invention.
2 is a cross-sectional view schematically showing an image display device according to a first embodiment of the present invention.
3 is a schematic plan view of a lower surface of a stereoscopic light guide plate of an image display device according to a first embodiment of the present invention.
4 is a photograph schematically illustrating a plurality of dot patterns provided on a lower surface of a three-dimensional light guide plate of an image display device according to the first embodiment of the present invention, and an enlarged photograph of the dot patterns.
5 is a diagram schematically illustrating a state in which a stereoscopic image is realized through a stereoscopic light guide plate of the image display device according to the first embodiment of the present invention.
6 is a diagram schematically illustrating a state in which a flat image is realized through a flat light guide plate of an image display device according to the first embodiment of the present invention.
7 is a diagram schematically illustrating that a view occurs in the left eye and the view in the right eye when a stereoscopic image is implemented in the image display device according to the first embodiment of the present invention.
8 is a diagram simulating whether a light guide plate serving as an optical filter when realizing a planar image in an image display device according to the first embodiment of the present invention deteriorates in planar image quality due to the lower arrangement of the image panel.
9 is a diagram illustrating the relationship between the thickness of a stereoscopic light guide plate and the user's viewing distance (D) in the liquid crystal display according to the second embodiment of the present invention, and the relationship between the basic structure and parameters of an actual barrier (Rear Barrier) It is a diagram for schematically explaining.
10 is an exploded perspective view schematically showing an image display device according to a second embodiment of the present invention.
11 is an image display device according to a second embodiment of the present invention, and is a schematic diagram for explaining a user's viewing distance when an uppermost three-dimensional light guide plate among a plurality of three-dimensional light guide plates is driven.
12 is a schematic diagram for explaining a user's viewing distance when a second stacked three-dimensional light guide plate among a plurality of three-dimensional light guide plates of an image display device according to a second embodiment of the present invention is driven.
13 is a schematic diagram illustrating a viewing distance of a user when the lowermost three-dimensional light guide plate among a plurality of three-dimensional light guide plates of an image display device according to a second embodiment of the present invention is driven.
14 is a diagram schematically illustrating an image display device according to a third embodiment of the present invention.
15 is a diagram schematically illustrating a distribution of light emitted from a light guide plate in an image display device according to a third exemplary embodiment of the present invention.
16 is an exploded perspective view schematically showing an image display device according to a fourth embodiment of the present invention.
17 is a cross-sectional view schematically showing an image display device according to a fourth embodiment of the present invention.
18 is a schematic diagram schematically illustrating a relationship between barrier films disposed under a three-dimensional light guide plate in an image display device according to a fourth embodiment of the present invention.
19 is an enlarged cross-sectional view of section “A” of FIG. 18 , schematically illustrating a state in which a barrier film is disposed under a light exit pattern provided inside a lower surface of a three-dimensional light guide plate.
20 is a diagram schematically illustrating a state in which a stereoscopic image is implemented through a stereoscopic light guide plate of an image display device according to a fourth embodiment of the present invention.
21 is an exploded perspective view schematically showing an image display device according to a fifth embodiment of the present invention.
22 is a cross-sectional view schematically showing an image display device according to a fifth embodiment of the present invention.
23 is a diagram schematically illustrating a three-dimensional light guide plate in an image display device according to a fifth embodiment of the present invention.
24 is an enlarged cross-sectional view of section “B” of FIG. 23 , schematically illustrating a state in which a light blocking film is formed on an outer surface of a light exit pattern provided in a three-dimensional light guide plate.
25 is a diagram schematically illustrating a state in which a stereoscopic image is realized through a stereoscopic light guide plate of an image display device according to a fifth embodiment of the present invention.

Hereinafter, a backlight unit and an image display device using the same according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Throughout the specification, like reference numbers refer to substantially the same but identical elements. In the following description, if it is determined that a detailed description of a known function or configuration related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. The component names used in the following description may be selected in consideration of the ease of writing the specification, and may be different from the part names of the actual product.

An image display apparatus using a backlight unit according to embodiments of the present invention may selectively implement a flat image and a stereoscopic image.

Since the backlight unit according to the embodiments of the present invention is included in the image display device of the present invention, the description of the backlight unit according to the embodiment of the present invention is not separately described. be replaced with

1 is an exploded perspective view schematically showing an image display device according to a first embodiment of the present invention.

2 is a cross-sectional view schematically showing an image display device according to a first embodiment of the present invention.

As shown in FIG. 1 , the image display device 100 according to the first embodiment of the present invention includes an image panel 110 on which a flat (2D) image or a stereoscopic (3D) image is implemented, and an image panel 110 . ) includes a backlight unit 120 that provides light.

As shown in FIG. 2 , the image panel 110 may be an image cell of a liquid crystal display (LCD), and a pair of transparent substrates disposed to face each other, that is, color The filter substrate 110a and the TFT array substrate 110b may include a liquid crystal layer (not shown) injected therebetween.

In addition, the image panel 110 includes various electrodes (not shown) for controlling the arrangement of liquid crystals, for example, electrodes such as a gate line, a data line, a source electrode, a drain electrode, and a common electrode, and a black matrix 112 . ) and a color filter 114 , and polarizing plates 118a and 118b may be attached to the upper and lower surfaces of the image panel 110 , respectively. In this case, the color filter 114 includes red (R), green (G), and blue (B) color filters 114r, 114g, and 114b.

And, the image display device 100 according to an embodiment of the present invention may include a driving circuit (not shown) for driving the image panel. Since the image panel 110 itself is obvious to those of ordinary skill in the art to which the present invention pertains, a more detailed description thereof will be omitted.

Furthermore, the backlight unit 120 has a structure similar to that of a general edge-type backlight, but the existing light guide plate is divided in the thickness direction so that two independent light guide plates, that is, the three-dimensional light guide plate 130 and the flat light guide plate 140 , are provided. It is applied, and the light source array that provides light to each light guide plate, that is, the first light source 132 and the second light source 142 is also independently configured to be selectively turned on according to a stereoscopic image or a flat image mode.

In particular, the backlight unit 120 irradiates light to the image panel 110, and when any one of a stereoscopic (3D) image and a flat (2D) image display mode is selected by the user, the surface light or the vertical direction It is configured to be able to irradiate a plurality of linear lights extending to the image panel 110, respectively.

The operation of the backlight unit 120 may be controlled by a driving circuit for driving the image panel 110 or may be controlled by a separately provided light source control unit.

1 and 2 , the backlight unit 120 includes two light guide plates and two light sources, that is, a three-dimensional light guide plate 130 and a flat light guide plate 140 and first and second light guide plates to selectively emit different types of light. Light sources 132 and 142 are provided.

The three-dimensional light guide plate 130 is disposed under the image panel 110 , and the flat light guide plate 140 is disposed under the three-dimensional light guide plate 130 . In this case, the three-dimensional light guide plate 130 and the flat light guide plate 140 may be respectively formed by injection molding a transparent thermoplastic resin such as an acrylic resin, a methacrylic resin, a styrene resin, or a polycarbonate resin.

3 is a schematic plan view of a lower surface of a stereoscopic light guide plate of an image display device according to a first embodiment of the present invention.

4 is a photograph schematically illustrating a plurality of dot patterns provided on a lower surface of a three-dimensional light guide plate of an image display device according to the first embodiment of the present invention, and an enlarged photograph of the dot patterns.

As shown in FIG. 3 , on the lower surface of the three-dimensional light guide plate 130 , a plurality of scattering patterns 134 are linearly spaced apart from each other. is formed to be spaced apart from each other in the cross direction, that is, along the width direction of the three-dimensional light guide plate 130 to form a linear shape, and a plurality of linear light exit patterns 134 are formed to be spaced apart from each other along the longitudinal direction of the three-dimensional light guide plate 130 . can In this case, the plurality of light exit patterns 134 may be arranged at regular intervals from each other, and the number of the plurality of light exit patterns 134 is not limited to the number shown in the drawings and may be variously changed. In particular, the plurality of light exit patterns 134 are processed in consideration of a pixel area of the display device and a viewing distance of an observer. In this case, when the first light source 132 is turned on, the light exit patterns 134 correspond to the emission area due to scattering when viewed from the front, and the area 136 between the plurality of linear light exit patterns 134 . ) is the total internal reflection region and appears dark.

In addition, the region 136 between the light exit patterns 134 allows a mirror reflection surface for total internal reflection to be generated. Accordingly, only portions of the light exit patterns 134 of the three-dimensional light guide plate 130 appear bright.

As described above, the image display device 100 using the backlight unit according to the first embodiment of the present invention is not controlled using a polarization component as in the conventional one to implement a stereoscopic (3D) image, but rather of the stereoscopic light guide plate 130 . Since the plurality of light exit patterns 134 formed on the lower surface are used, a separate polarizing material such as the conventional one, for example, parts such as an RM lens or a polarization control film is unnecessary.

In addition, the plurality of light exit patterns 134 may be formed in any pattern capable of diffusely reflecting and scattering light. The plurality of light exit patterns 134 may be formed in various shapes such as, for example, a concave pattern, a protruding pattern, or a dot pattern, and the light exit pattern 134 may be haze-treated to increase the scattering effect. may be At this time, as shown in FIG. 4 , in the present invention, a case in which the plurality of light exit patterns 134 are designed in the form of an intaglio dot pattern will be described as an example.

On the other hand, the flat light guide plate 140 has the same light profile as a light guide plate for a general planar (2D) image model, and has a uniform surface due to the optical sheet 160 disposed on it and the reflective sheet 170 disposed below it. It will act as a light source. In this case, since the three-dimensional light guide plate 130 is a transparent substrate, it can be seen that the effect on transmittance is insignificant.

Meanwhile, the first light source 132 is disposed to correspond to the side surface of the three-dimensional light guide plate 130 , that is, the first light incident surface 130a, so as to irradiate light into the interior of the three-dimensional light guide plate 130 , and the second light source Reference numeral 142 is disposed to correspond to the side surface of the flat light guide plate 140 , that is, the second light incident surface 140a so as to radiate light into the flat light guide plate 140 .

In addition, the first light source 132 and the second light source 142 may be formed of various types of light sources, such as a light emitted diode (LED) and a cold cathode fluorescent lamp (CCFL), respectively. In the present invention, a case in which a light emitted diode (LED) is used as a light source will be described as an example.

The first light source 132 and the second light source 142 may have a shape extending in the longitudinal direction along the side surface (ie, the light incident surface) of the three-dimensional light guide plate 130 and the flat light guide plate 140 , and each light source is one light source. may be formed, and as shown in FIG. 1 , a plurality of light sources may be arranged in a line.

1 shows that the first light source 132 and the second light source 142 are provided with three each, there is a special limitation in the number and position of the first light source 132 and the second light source 142. However, each of the first light source 132 and the second light source 142 may be provided one by one.

The first light source 132 and the second light source 142 are configured to be separately turned on. That is, if necessary, only one of the first light source 132 and the second light source 142 may be turned on and the other one may be controlled to be off.

For example, when the image display device according to the first embodiment of the present invention operates to implement a stereoscopic (3D) image, the first light source 132 is turned on and the second light source 142 is turned off ( off), and when the image display device according to the first embodiment of the present invention operates to implement a flat (2D) image, the first light source 132 is turned off and the second light source 142 is turned on ( on) will be

In addition, the optical sheet 160 is disposed on the second light guide plate 130 . At this time, although not shown in the drawings, the optical sheet 160 may include a diffusion sheet, a prism sheet, and a protection sheet.

The optical sheet 160 performs a function of irradiating the entire surface of the image panel 110 in a more uniform state to light incident by the flat light guide plate 140 and exiting the second light exit surface 140b. As such, since the optical sheet 160 itself is apparent to those of ordinary skill in the art to which the present invention pertains, a more detailed description thereof will be omitted.

A reflective sheet 170 is disposed under the flat light guide plate 140 . The reflective sheet 170 reflects the light emitted from the lower surface of the flat light guide plate 140 among the light introduced into the flat light guide plate 140 to flow back into the flat light guide plate 140 , thereby reducing light loss and overall light efficiency. functions to increase

In the case of the three-dimensional light guide plate 130 of the image display device according to the first embodiment of the present invention having the above configuration, among the light introduced into the three-dimensional light guide plate 130, the portion where the plurality of light exit patterns 134 are not formed That is, the light reaching the region 136 between the plurality of light exit patterns 134 that are linear, respectively, is reflected and travels back into the three-dimensional light guide plate 130 , and the light reaching the plurality of light exit patterns 134 is The scattered light is emitted to the outside of the first light exit surface 130b of the three-dimensional light guide plate 130 through the light exit pattern 134 .

Accordingly, the three-dimensional light guide plate 130 emits light in the form of linear light by the plurality of linear light output patterns 134 formed to be spaced apart from each other, and the emitted light is incident on the image panel 110 .

On the other hand, in the case of the flat light guide plate 140 of the image display device 100 according to the first embodiment of the present invention, the light introduced from the second light source 142 facing the second light incident surface 140a is converted into a flat surface. Surface light is emitted over the entire upper surface of the light guide plate 140 , that is, the second light exit surface 140b to be emitted toward the image panel 110 . That is, the flat light guide plate 140 emits light distributed over the entire second light exit surface 140b, similar to a light guide plate used in a conventional liquid crystal display device.

To this end, a pattern for scattering light may be formed on the upper surface of the planar light guide plate 140 , and such a pattern may be implemented in various patterns such as a prism pattern and a dot pattern. In this case, the light emitted from the flat light guide plate 140 may be converted into a more uniform state by the optical sheet 160 described above and then irradiated to the image panel 110 .

In the image display apparatus 100 according to the first embodiment of the present invention configured as described above, the first light source 132 and the second light source 142 are selectively controlled to be turned on, thereby displaying a stereoscopic (3D) image and A planar (2D) image may be selectively implemented.

A case in which the stereoscopic image and the flat image are selectively implemented in the image display device according to the first embodiment of the present invention will be described with reference to FIGS. 5 and 6 as follows.

5 is a diagram schematically illustrating a state in which a stereoscopic image is realized through a stereoscopic light guide plate of the image display device according to the first embodiment of the present invention.

6 is a diagram schematically illustrating a state in which a flat image is realized through a flat light guide plate of an image display device according to the first embodiment of the present invention.

In the image display device 100 according to the first embodiment of the present invention, a flat image and a stereoscopic image are selectively operated depending on whether the three-dimensional light guide plate 130 or the flat light guide plate 140 is used, which is the first light source 132 . ) and a method of selectively lighting the second light source 142 can be implemented. In particular, when the three-dimensional light guide plate 130 and the flat light guide plate 140 have the same size, the load capacity of the first light source 132 and the second light source 142 is the same, so there is no need to separately apply a light source driver. It can be used in common, and only the output direction can be selectively designed.

When implementing a stereoscopic image, as shown in FIG. 5 , the first light source 132 is turned on and the second light source 142 is turned off. In this case, a plurality of linear light is emitted through a plurality of linear light exit patterns 134 that are spaced apart from each other on the lower surface of the three-dimensional light guide plate 130 and formed in the longitudinal direction of the three-dimensional light guide plate, and the emitted light is transmitted to the image panel 110 . is entered into

Accordingly, the light refracted from each of the outgoing light patterns 134 passes through different pixel areas of the image panel 110 and then reaches the left eye 182 and the right eye 184 of the viewer, respectively. That is, light reaching the observer's left eye 182 passes through a path indicated by a dotted line, and light reaching the observer's right eye 184 has a path indicated by a solid line.

7 is a diagram schematically illustrating that a view occurs in the left eye and the view in the right eye when a stereoscopic image is implemented in the image display device according to the first embodiment of the present invention.

Accordingly, as shown in FIG. 7 , the left eye and the right eye of the observer see a color image in different images, that is, the left eye (not shown, see 182 of FIG. 5 ) and the right eye (not shown, see 184 of FIG. 5 ). In , when viewing a dark image, a separation between views occurs, and the observer feels a stereoscopic (3D) image due to the observed image difference. At this time, pixel regions of the image panel 110 positioned in paths through which light emitted from the same light exit pattern 134 and reaching the left and right eyes of the observer passes are driven to display different images.

Meanwhile, referring to FIG. 6 , when realizing a planar (2D) image, the first light source 132 is turned off and the second light source 142 is turned on. The light emitted from the second light source 142 is emitted through the front surface of the second light exit surface 140b of the flat light guide plate 140 , passes through the stereoscopic light guide plate 130 , and then is irradiated to the image panel 110 .

Accordingly, the observer perceives the image displayed on the image display device as a two-dimensional (2D) flat image in the same way as in the general image display device.

8 is a diagram simulating whether a light guide plate serving as an optical filter when realizing a planar image in an image display device according to the first embodiment of the present invention deteriorates in planar image quality due to the arrangement of the lower side of the image panel.

As shown in FIG. 8 , a flat light guide plate 140 serving as an optical filter when realizing a flat image in the image display device according to the first embodiment of the present invention is disposed below the image panel 110 . It can be seen that, even if it is disposed in the , the deterioration of the plane (2D) image quality due to the light guide plate does not occur.

As described above, the image display device using the backlight unit according to the present invention enables the realization of a flat image and a stereoscopic image by selectively driving two light guide plates having a low cost and a simple structure.

In addition, since the image display device using the backlight unit according to the present invention is not controlled using a polarization component as in the conventional one for realization of a flat image and a stereoscopic image, a separate polarization material, for example, an RM lens or a polarization control film and the like are unnecessary.

And, since the image display device using the backlight unit according to the present invention has a structure in which light guide plates serving as optical filters are disposed on the rear surface, substrates serving as an optical filter for view division are displayed. Since it is attached to the uppermost layer of the screen, the image quality deterioration phenomenon caused by the attached optical filter when the 2D mode is switched is eliminated.

Meanwhile, an image display device according to a second embodiment of the present invention to which a plurality of three-dimensional light guide plates is applied will be described in detail with reference to the accompanying drawings.

9 is a diagram illustrating the relationship between the thickness of a stereoscopic light guide plate and a user's viewing distance (D) in the liquid crystal display according to the second embodiment of the present invention, and the relationship between the basic structure and parameters of an actual barrier (Rear Barrier) It is a diagram for schematically explaining.

As shown in FIG. 9 , the design of the viewing distance D is changed according to the thickness of the stereoscopic light guide plate.

A light guide plate for a stereoscopic image exists to implement a stereoscopic (3D) image mode, and this stereoscopic light guide plate is manufactured based on an actual rear barrier design method.

Formula (1) ---- D = (ES/P - S)/n,

Formula (2) ---- Q = (1+B/P - 2R/E) / (1/P - 1/E)

Formula (3) ---- M = (1-B/P + 2R/E) / (1/P - 1/E)

Here, E means both eyes applied during design, that is, the distance between the left and right eyes, for example, 60 ~ 65 mm, P means the unit pitch of the stereoscopic (3D) image on the image panel, fixed according to the model.

And, B means the width of the black matrix, and it is fixed together with P according to the selection model. n is the refractive index of the substrate, and is applied when calculating the viewing distance by refraction of light. Moreover, M denotes a barrier pattern width, and D denotes a distance between an image cell and a viewing point (ie, an appropriate 3D viewing distance).

In manufacturing the three-dimensional light guide plate, parameters may be a thickness (T) and a pattern width (W). As in Equation (1) above, the thickness (T) of the stereoscopic light guide plate is related to the viewing distance (D), and the width (W) of the dot pattern is the viewing margin (2R) of the stereoscopic (3D) image. is related to

As shown in Equation (1), when the thickness (T) of the light guide plate is changed, the value of the barrier pattern, that is, the distance (S) between the dot pattern and the image panel, changes, and affects the viewing distance (D) of the stereoscopic (3D) image. go crazy

And, as in Equation (2), (Q + M) is always the same according to the selected model, and the viewing margin 2R is changed when the ratio of the light emitting part of the three-dimensional light guide plate, that is, the width of the dot pattern is adjusted.

An image display apparatus using a backlight unit according to a second embodiment of the present invention using the relationship between the thickness of the light guide plate and the viewing distance of the user will be described with reference to FIGS. 10 to 13 as follows.

Here, a case in which three three-dimensional light guide plates are stacked up and down will be described, but the present invention is not limited to three three-dimensional light guide plates. .

10 is an exploded perspective view schematically showing an image display device according to a second embodiment of the present invention.

As shown in FIG. 10 , the image display device 200 according to the second embodiment of the present invention includes an image panel 210 on which a flat (2D) image or a stereoscopic (3D) image is implemented, and an image panel 210 ) and a backlight unit 220 that provides light.

The image panel 210 may be an image cell of a liquid crystal display (LCD), and a pair of transparent substrates disposed to face each other, that is, a color filter substrate (not shown) and a TFT. It may include an array substrate (not shown) and a liquid crystal layer (not shown) injected therebetween.

In addition, although not shown in the drawings, the image panel 210 includes various electrodes (not shown) for controlling the arrangement of liquid crystals, for example, electrodes such as a gate line and a data line, a source electrode, a drain electrode, and a common electrode. and a black matrix (not shown) and a color filter (not shown), and a polarizing plate (not shown) may be attached to the upper and lower surfaces of the image panel 210 , respectively.

The image display device 200 according to the second embodiment of the present invention may include a driving circuit (not shown) for driving the image panel.

Moreover, the backlight unit 220 has a structure similar to that of a general edge-type backlight, but is disposed under the plurality of three-dimensional light guide plates 232, 234, 236 and the lowermost three-dimensional light guide plate 236 stacked up and down. It includes a flat light guide plate 250 and a light source array that provides light to each light guide plate, that is, a first light source 262 and a second light source 264 . In this case, the first light source 262 and the second light source 264 have a structure in which light is selectively turned on according to a stereoscopic image or a flat image mode.

The three-dimensional light guide plates 232 , 234 , and 236 are stacked vertically so that the three-dimensional light guide plates can be selectively driven according to a change in the viewing distance D of the user.

In addition, the three-dimensional light guide plates 232, 234, and 236 have different thicknesses according to the user's viewing distance (D), in addition to stacking the three-dimensional light guide plates of the same thickness and a light source array (LED Array). It is possible to use

A user's viewing distance (not shown, see D of FIG. 9 ) is proportional to the number of the three-dimensional light guide plates 232 , 234 , and 236 . That is, assuming that the user's viewing distance is D1 when the first three-dimensional light guide plate 232 is driven, the user's viewing distance D2 has a value of D1 × 2 when the second light incident light guide plate 234 is driven . In addition, when the third stereoscopic light guide plate 236 is driven, the user's viewing distance D3 has a value of D1×3.

In this case, the light source arrays applied to each of the three-dimensional light guide plates 232 , 234 , and 236 should be selectively driven one by one. In particular, the light source array operating according to the distance between the user and the screen, that is, the image panel 200 (not shown, see S of FIG. 11 ) may be changed.

In particular, the backlight unit 220 irradiates light to the image panel 210, and when any one of a stereoscopic (3D) image and a flat (2D) image display mode is selected by the user, the backlight unit 220 emits light in the plane light or in the vertical direction. It is configured to irradiate a plurality of extended linear lights to the image panel 210, respectively.

The operation of the backlight unit 220 may be controlled by a driving circuit for driving the image panel 210 or may be controlled by a separately provided light source control unit.

In addition, an optical sheet 240 is disposed on the flat light guide plate 250 . At this time, although not shown in the drawings, the optical sheet 240 may include a diffusion sheet, a prism sheet, and a protection sheet.

The optical sheet 240 performs a function of irradiating the entire surface of the image panel 210 in a more uniform state, such as light incident by the flat light guide plate 250 and emitted to the second light exit surface (not shown). . As such, since the optical sheet 240 itself is apparent to those of ordinary skill in the art to which the present invention pertains, a more detailed description thereof will be omitted.

A reflective sheet 270 is disposed under the flat light guide plate 250 . The reflective sheet 270 reflects the light emitted from the lower surface of the flat light guide plate 250 among the light introduced into the flat light guide plate 250 to flow back into the flat light guide plate 250 , thereby reducing the loss of light and reducing overall light efficiency. It performs the function of increasing

11 is an image display device according to a second embodiment of the present invention, and is a schematic diagram for explaining a user's viewing distance when an uppermost three-dimensional light guide plate among a plurality of three-dimensional light guide plates is driven.

12 is a schematic diagram for explaining a user's viewing distance when a second stacked three-dimensional light guide plate among a plurality of three-dimensional light guide plates of an image display device according to a second embodiment of the present invention is driven.

13 is a schematic view for explaining a viewing distance of a user when the lowermost three-dimensional light guide plate among a plurality of three-dimensional light guide plates of an image display device according to a second embodiment of the present invention is driven.

11 to 13 , the backlight unit 220 includes first, second, and third three-dimensional light guide plates 232 , 234 and 236 stacked vertically to selectively emit different types of light, and a flat light guide plate 350 . ) and first and second light sources 262 and 264 .

The first, second, and third three-dimensional light guide plates 232 , 234 , and 236 are vertically disposed under the image panel 210 , and the flat light guide plate 250 is disposed under the third three-dimensional light guide plate 236 . At this time, the first, second, and third three-dimensional light guide plates 232, 234, 236 and the flat light guide plate 250 are formed by injection molding a transparent thermoplastic resin such as an acrylic resin, a methacryl resin, a styrene resin, or a polycarbonate resin, respectively. can

11 to 13, on the lower surfaces of the first, second, and third three-dimensional light guide plates 232, 234, and 236, a plurality of scattering patterns 232a, 234a, 236a are spaced apart from each other. are formed to be spaced apart from each other in the cross direction with respect to the traveling direction of the light emitted from the first light source 262, that is, in the width direction of the first, second and third three-dimensional light guide plates 232, 234, 236, The plurality of linear light exit patterns 232a, 234a, and 236a may be formed to be spaced apart from each other in the longitudinal direction of the first, second, and third three-dimensional light guide plates 232, 234, and 236.

In this case, the plurality of light exit patterns 232a , 234a , and 236a may be arranged at regular intervals from each other, and the number of the plurality of light exit patterns 232a , 234a , 236a is not limited to the number shown in the drawings and is variously changed. can be In particular, the plurality of light exit patterns 232a, 234a, and 236a are processed in consideration of the pixel area of the display device and the viewing distance D of the viewer. At this time, when the first light source 262 is turned on, the light outgoing patterns 232a , 234a and 236a of the first light incident light guide plate 232 correspond to the light emitting area due to scattering when viewed from the front, and a plurality of The non-patterned areas 232b, 234b, and 236b between the outgoing light patterns 232a, 234a, and 236a appear dark as total internal reflection areas.

In addition, the non-patterned regions 232b, 234b, and 236c between the light exit patterns 232a, 234a, and 236a generate a mirror reflection surface for total internal reflection. Accordingly, only portions of the light exit patterns 232a, 234a, and 236a of the first, second, and third three-dimensional light guide plates 232 , 234 and 236 are brightly displayed.

As described above, the image display apparatus 200 using the backlight unit according to the second embodiment of the present invention does not control using the polarization component as in the prior art to implement a stereoscopic (3D) image, but rather the first, second and Since a plurality of light exit patterns 232a, 234a, 236a formed on the lower surface of the third three-dimensional light guide plate 232, 234, 236 are used, a separate polarizing material such as the conventional one, for example, an RM lens or a polarization control film, etc. will become unnecessary

In addition, the plurality of light exit patterns 232a , 234a , and 236a may be formed in an arbitrary pattern capable of diffusely reflecting and scattering light. The plurality of light exit patterns 232a, 234a, and 236a may be formed in various shapes such as, for example, a concave pattern, a protruding pattern, or a dot pattern, and the light exit patterns 232a, 234a, 236a exhibit a scattering effect. It may also be haze to heighten. In the present invention, a case in which the plurality of light exit patterns 232a, 234a, and 236a are designed in the form of an intaglio dot pattern will be described as an example.

The flat light guide plate 250 has the same light profile as the light guide plate for a general planar (2D) image model, and due to the optical sheet 240 disposed on it and the reflective sheet 270 disposed below it, a uniform surface light source is formed. will take on the role. In this case, since the first, second, and third three-dimensional light guide plates 232 , 234 , and 236 are transparent substrates, it can be seen that they have little effect on transmittance.

Meanwhile, the first light source 232 includes first, second and third three-dimensional light guide plates ( The side surfaces of 232 , 234 , and 236 are disposed to correspond to the first light incident surface (not shown), and the second light source 264 is a flat light guide plate 250 to irradiate light into the flat light guide plate 250 . is disposed to correspond to the side of the , that is, the second light incident surface (not shown).

In addition, the first light source 262 and the second light source 264 may be formed of various types of light sources, such as a light emitted diode (LED) and a cold cathode fluorescent lamp (CCFL), respectively. In the present invention, a case in which a light emitted diode (LED) is used as a light source will be described as an example.

The first light source 262 and the second light source 264 may have a shape extending in the longitudinal direction along the side surface (ie, the light incident surface) of the three-dimensional light guide plates 232 , 234 , 236 and the flat light guide plate 250 , , may be formed of a plurality of light source arrays or one light source array each.

The first light source 262 and the second light source 264 are configured to be separately turned on. That is, if necessary, either one of the first light source 262 and the second light source 264 may be controlled to be turned on and the other one may be turned off.

For example, when the image display device 200 according to the second embodiment of the present invention operates to implement a stereoscopic (3D) image, the first light source 262 is turned on and the second light source 264 is turned on. is off, and when the image display device according to the second embodiment of the present invention operates to implement a planar (2D) image, the first light source 262 is turned off and the second light source 264 is turned off. is made possible by turning it on.

11 is a case in which a stereoscopic (3D) image is implemented through the first stereoscopic light guide plate 232 on the uppermost side of the image display device 200 according to the second embodiment of the present invention. , the first light source 262 is turned on in a state in which the first light source 262 is disposed to face one side of the first three-dimensional light guide plate 232 , and the second light source 264 is disposed to face one side of the flat light guide plate 250 . is off (off). At this time, when the image display device 200 according to the second embodiment of the present invention operates to implement a planar (2D) image, the first light source 262 is turned off, and the second light source 264 is turns on

11, in order to implement a stereoscopic (3D) image through the uppermost first stereoscopic light guide plate 232, the first light source 262 When turned on in a state disposed opposite to one side, among the light introduced into the first three-dimensional light guide plate 232 , the plurality of light exit patterns 232a are not formed, that is, a plurality of linearly formed portions. The light reaching the non-patterned area 232b between the light exit patterns 232a is reflected, and then travels back to the inside of the first three-dimensional light guide plate 232 , and the light reaching the plurality of light exit patterns 232a is scattered to form an exit pattern. The light is emitted toward the image panel 210 above the first three-dimensional light guide plate 232 through 232a.

Accordingly, the first three-dimensional light guide plate 232 emits light in the form of linear light by the light exit patterns 232a formed to be spaced apart from each other, and the emitted light is incident on the image panel 210, so that the user can view stereoscopic (3D) images.

Accordingly, the viewing distance D1 of the user when the first three-dimensional light guide plate 232 is applied among the plurality of three-dimensional light guide plates 232 , 234 , and 236 is, as in Equation (1) of FIG. 9 , the first three-dimensional light guide plate It is determined by the distance S1 between the light exit pattern 232a of 232 and the image panel 210 .

Meanwhile, FIG. 12 is a case in which a stereoscopic (3D) image is implemented through the second stereoscopic light guide plate 234 on the central side of the image display device 200 according to the second embodiment of the present invention. As shown, the first light source 262 is turned on in a state in which the first light source 262 is disposed to face one side of the second three-dimensional light guide plate 234 , and the second light source 262 is disposed to face one side of the flat light guide plate 250 ( 264) is off. At this time, when the image display device 200 according to another embodiment of the present invention operates to implement a planar (2D) image, the first light source 262 is turned off, and the second light source 264 is turned on. It is made possible by making it (on).

As such, as shown in FIG. 12 , in order to implement a stereoscopic (3D) image through the second stereoscopic light guide plate 234 on the central side, the first light source 262 is the second stereoscopic light guide plate 234 . When turned on in a state disposed opposite to one side, among the light introduced into the second three-dimensional light guide plate 234 , the plurality of light exit patterns 234a are not formed, that is, a plurality of linearly formed portions. The light reaching the non-patterned area 234b between the light exit patterns 234a is reflected, and then travels back into the second three-dimensional light guide plate 234 , and the light reaching the plurality of light exit patterns 234a is scattered to form an exit pattern. It is emitted toward the image panel 210 on the upper side of the first three-dimensional light guide plate 232 through 234a.

Accordingly, the second three-dimensional light guide plate 234 emits light in the form of linear light by the light exit patterns 234a formed to be spaced apart from each other, and the emitted light is incident on the image panel 210, so that the user can view stereoscopic (3D) images.

Accordingly, the viewing distance D2 of the user when the second three-dimensional light guide plate 234 is applied among the plurality of three-dimensional light guide plates 232 , 234 , and 236 is, as in Equation (1) of FIG. 9 , the second three-dimensional light guide plate It is determined by the distance S2 between the light exit pattern 234a of 234 and the image panel 210 . That is, it can be seen that the user's viewing distance D2 when the second three-dimensional light guide plate 234 is applied is twice the user's viewing distance D1 when the first three-dimensional light guide plate 232 is applied. .

13 is a case in which a stereoscopic (3D) image is implemented through the third stereoscopic light guide plate 236 on the lowermost side of the image display device 200 according to the second embodiment of the present invention. As shown, the first light source 262 is turned on in a state in which the first light source 262 is disposed to face one side of the third three-dimensional light guide plate 236 , and the second light source 262 is disposed to face one side of the flat light guide plate 250 ( 264) is off. At this time, when the image display device 200 according to the second embodiment of the present invention operates to implement a planar (2D) image, the first light source 262 is turned off, and the second light source 264 is It is made possible by turning it on.

As shown in FIG. 13 , in order to implement a stereoscopic (3D) image through the third stereoscopic light guide plate 236 on the central side, a first light source 262 is disposed on one side of the second stereoscopic light guide plate 236 . When the first light source 262 is turned on while facing each other, among the light introduced into the third three-dimensional light guide plate 236 , the plurality of light exit patterns 236a are not formed, i.e., they are linear. Light reaching the non-patterned area 236b between the plurality of light exit patterns 236a forming The scattered light is emitted toward the image panel 210 above the first three-dimensional light guide plate 232 through the light exit pattern 236a.

Accordingly, the third three-dimensional light guide plate 236 emits light in the form of linear light by the light exit patterns 236a formed to be spaced apart from each other, and the emitted light is incident on the image panel 210, so that the user can view stereoscopic (3D) images.

Accordingly, the viewing distance D3 of the user when the third three-dimensional light guide plate 236 is applied among the plurality of three-dimensional light guide plates 232 , 234 , and 236 is, as in Equation (1) of FIG. 9 , the third three-dimensional light guide plate It is determined by the distance S3 between the light exit pattern 236a of 236 and the image panel 210 . That is, it can be seen that the user's viewing distance D3 when the third three-dimensional light guide plate 236 is applied can be three times the user's viewing distance D1 when the first three-dimensional light guide plate 232 is applied. can

As described above, in the image display device using the backlight unit according to the present invention, a flat image and a stereoscopic image can be realized by selectively driving a plurality of light guide plates having a low cost and simple structure.

In addition, since the image display device using the backlight unit according to the present invention is not controlled using a polarization component as in the conventional one for realization of a flat image and a stereoscopic image, a separate polarization material, for example, an RM lens or a polarization control film and the like are unnecessary.

And, since the image display device using the backlight unit according to the present invention has a structure in which light guide plates serving as optical filters are disposed on the rear surface, substrates serving as an optical filter for view division are displayed. Since it is attached to the uppermost layer of the screen, the image quality deterioration phenomenon caused by the attached optical filter when the 2D mode is switched is eliminated.

In the image display device using the backlight unit according to the present invention, a stereoscopic (3D) image and a planar (2D) image are selectively realized as well as a stereoscopic image by selectively controlling the first light source and the second light source to be turned on. It is possible to adjust the viewing distance of a stereoscopic (3D) image by designing the three-dimensional light guide plates that affect the (3D) viewing distance to be stacked up and down so that each light guide plate is driven according to the viewing distance environment of the display user.

Meanwhile, an image display device using a backlight unit according to a third embodiment of the present invention with a light blocking film interposed between the three-dimensional light guide plate and the flat light guide plate will be described with reference to FIGS. 14 and 15 as follows.

14 is a diagram schematically illustrating an image display device according to a third embodiment of the present invention.

15 is a diagram schematically illustrating a distribution of light emitted from a light guide plate in an image display device according to a third embodiment of the present invention.

As shown in FIG. 14 , the image display device 300 according to the third embodiment of the present invention includes an image panel 310 on which a flat (2D) image or a stereoscopic (3D) image is implemented, and an image panel 310 ) and a backlight unit 320 that provides light.

Although not shown in the drawing, the image panel 310 may be an image cell of a liquid crystal display (LCD), and may be a pair of transparent substrates disposed to face each other, that is, a color filter substrate. (not shown, see 110a of FIG. 2 ) and a TFT array substrate (not shown, see 110b of FIG. 2 ) and a liquid crystal layer (not shown) injected therebetween.

In addition, the image panel 310 includes various electrodes (not shown) for controlling the arrangement of liquid crystals, for example, electrodes such as a gate line, a data line, a source electrode, a drain electrode, and a common electrode, and a black matrix (not shown). , 112 in FIG. 2) and a color filter (not shown, see 114 in FIG. 2), etc., and polarizing plates (not shown, see 118a and 118b in FIG. 2) on the upper and lower surfaces of the image panel 110) Each of these may be attached. In this case, the color filter 114 includes red (R), green (G), and blue (B) color filters (not shown, refer to 114r, 114g, and 114b of FIG. 2 ).

And, the image display device 300 according to the third embodiment of the present invention may include a driving circuit (not shown) for driving the image panel. Since the image panel 310 itself is obvious to those of ordinary skill in the art to which the present invention pertains, a more detailed description thereof will be omitted.

Moreover, the backlight unit 320 has a structure similar to that of a general edge-type backlight, but the existing light guide plate is divided in the thickness direction so that two independent light guide plates, that is, the three-dimensional light guide plate 330 and the flat light guide plate 350 are The light source array that provides light to each light guide plate, that is, the first light source 362 and the second light source 364 are also independently configured to be selectively lit according to a stereoscopic image or a planar image mode.

In particular, the backlight unit 320 irradiates light to the image panel 310, and when any one of a stereoscopic (3D) image and a flat (2D) image display mode is selected by the user, the surface light or the vertical direction It is configured to be able to irradiate a plurality of linear lights extending to the image panel 310, respectively.

The operation of the backlight unit 320 may be controlled by a driving circuit for driving the image panel 310 or may be controlled by a separately provided light source control unit.

14 , the backlight unit 320 includes two light guide plates and two light sources, that is, a three-dimensional light guide plate 330 and a flat light guide plate 350 and first and second light guide plates to selectively emit different types of light. Light sources 362 and 364 are provided.

The three-dimensional light guide plate 330 is disposed under the image panel 310 , and the flat light guide plate 350 is disposed under the three-dimensional light guide plate 330 . In this case, the three-dimensional light guide plate 330 and the flat light guide plate 350 may be respectively formed by injection molding a transparent thermoplastic resin such as an acrylic resin, a methacrylic resin, a styrene resin, or a polycarbonate resin.

As shown in FIG. 14 , on the lower surface of the three-dimensional light guide plate 330 , a plurality of scattering patterns 330a are linearly arranged in a direction in which light emitted from the first light source 362 is spaced apart from each other. is formed to be spaced apart from each other in the cross direction, that is, along the width direction of the three-dimensional light guide plate 330 to form a linear shape, and a plurality of linear light exit patterns 330a are formed to be spaced apart from each other in the longitudinal direction of the three-dimensional light guide plate 330. can

In this case, the plurality of light exit patterns 330a may be arranged at regular intervals from each other, and the number of the plurality of light exit patterns 330a is not limited to the number shown in the drawings and may be variously changed. In particular, the plurality of light exit patterns 330a are processed in consideration of a pixel area of the display device and a viewing distance of an observer. At this time, when the first light source 362 is turned on, the light emitting patterns 330a correspond to a light emitting area due to scattering when viewed from the front, and a region between the plurality of linear light emitting patterns 330a (not shown). H) appears dark as a total internal reflection area.

In addition, the region between the light exit patterns 330a is such that a mirror reflection surface for total internal reflection is generated. Accordingly, only portions of the light exit patterns 330a of the three-dimensional light guide plate 330 appear bright.

As described above, the image display device 300 using the backlight unit according to the third embodiment of the present invention is not controlled using a polarization component as in the conventional one to implement a stereoscopic (3D) image, but rather of the stereoscopic light guide plate 330 . Since the plurality of light exit patterns 330a formed on the lower surface are used, a separate polarizing material such as the conventional one, for example, parts such as an RM lens or a polarization control film is unnecessary.

In addition, the plurality of light exit patterns 330a may be formed in any pattern capable of diffusely reflecting and scattering light. The plurality of light exit patterns 330a may be formed in various shapes such as, for example, a concave pattern, a protruding pattern, or a dot pattern, and the light exit pattern 330a may be haze-treated to increase the scattering effect. may be In the present invention, a case in which the plurality of light exit patterns 330a are designed in the form of engraved dot patterns will be described as an example.

The flat light guide plate 350 disposed below the three-dimensional light guide plate 330 has the same light profile as that of a general planar (2D) image model light guide plate, and the optical sheet 340 disposed on the planar light guide plate 350 and the reflective sheet disposed thereunder Due to (370), it plays the role of a uniform planar light source. In this case, since the three-dimensional light guide plate 330 is a transparent substrate, it can be seen that the effect on transmittance is insignificant. Although not shown in the drawings, the optical sheet 340 may include a diffusion sheet, a prism sheet, and a protection sheet.

The optical sheet 340 performs a function of irradiating the entire surface of the image panel 310 in a more uniform state to light incident by the flat light guide plate 350 and exiting the light exit surface (not shown). As such, since the optical sheet 340 itself is obvious to those of ordinary skill in the art to which the present invention pertains, a more detailed description thereof will be omitted.

A reflective sheet 370 is disposed under the flat light guide plate 350 . The reflective sheet 370 reflects the light emitted from the lower surface of the flat light guide plate 350 among the light introduced into the flat light guide plate 350 to flow back into the flat light guide plate 350 , thereby reducing the loss of light and reducing overall light efficiency. functions to increase

In addition, the first light source 362 and the second light source 364 may be formed of various types of light sources, such as a light emitted diode (LED) and a cold cathode fluorescent lamp (CCFL), respectively. In the present invention, a case in which a light emitted diode (LED) is used as a light source will be described as an example.

The first light source 362 and the second light source 364 may have a shape extending in the longitudinal direction along the side surface (ie, the light incident surface) of the three-dimensional light guide plate 330 and the planar light guide plate 350 , each of one light source may be formed, and a plurality of light sources may be arranged in a line.

The number and position of the first light source 362 and the second light source 364 are not particularly limited, and one first light source 362 and one second light source 364 may be provided, respectively.

The first light source 362 and the second light source 364 are configured to be separately turned on. That is, if necessary, either one of the first light source 362 and the second light source 364 may be controlled to be turned on and the other one may be turned off.

For example, when the image display device 330 operates to implement a stereoscopic (3D) image, the first light source 362 is turned on and the second light source 364 is turned off, and the image is displayed. When the device 300 operates to implement a planar (2D) image, the first light source 362 is turned off and the second light source 364 is turned on.

And, as shown in FIGS. 14 and 15 , a shading film 380 is disposed between the three-dimensional light guide plate 330 and the optical sheet 340 . In this case, the light blocking film 380 plays a role of physically blocking or reducing light leaking between the light exit patterns 330 of the three-dimensional light guide plate 330 and the optical sheet 340 .

As such, since the shading film 380 is interposed between the stereoscopic light guide plate 330 and the optical sheet 340 , the level of cross talk (CT) of the stereoscopic image display device 300 is greatly improved. can be In particular, as the transmittance α of the light blocking film 380 decreases, the crosstalk (3D CT) of the image display device is greatly reduced.

Equation (4) --- 3D CT (Crosstalk) = (B _L W _R - B _L B _R ) / (W _L B _R - B _L B _R ) × 100

As shown in Equation (4), it is the amount of leakage light × (α) ² This is because it acts as a factor that reduces the size of

As described above, the image display device using the backlight unit according to the present invention enables the realization of a flat image and a stereoscopic image by selectively driving two light guide plates having a low cost and a simple structure.

In addition, since the image display device using the backlight unit according to the present invention is not controlled using a polarization component as in the conventional one for realization of a flat image and a stereoscopic image, a separate polarization material, for example, an RM lens or a polarization control film and the like are unnecessary.

And, since the image display device using the backlight unit according to the present invention has a structure in which light guide plates serving as optical filters are disposed on the rear surface, substrates serving as an optical filter for view division are displayed. Since it is attached to the uppermost layer of the screen, the image quality deterioration phenomenon caused by the attached optical filter when the 2D mode is switched is eliminated.

Furthermore, the backlight unit and the image display device using the same according to the present invention can reduce leakage light by arranging a shading film having a specific transmittance under the stereoscopic light guide plate, so that stereoscopic (3D) in the stereoscopic image display device. It is possible to improve image quality characteristics. In particular, as the light blocking effect by the non-pattern region increases due to a decrease in light leaking from the three-dimensional light guide plate to the flat light guide plate below it, the cross-talk of the three-dimensional image is greatly reduced. The quality of the stereoscopic image may be improved.

However, although the light-shielding film applied in the third embodiment of the present invention can reduce light leakage from the three-dimensional light guide plate, the transmittance is rather low, so that a part of the flat luminance through the flat light guide plate may be lost when realizing a flat image. .

However, according to the fourth and fifth embodiments of the present invention, which will be described later, it is possible to reduce light leakage from the stereoscopic light guide plate and prevent loss of a part of the plane luminance when realizing a plane image.

An image display apparatus using a backlight unit according to a fourth embodiment of the present invention will be described with reference to FIGS. 16 to 20 as follows.

16 is an exploded perspective view schematically showing an image display device according to a fourth embodiment of the present invention.

17 is a cross-sectional view schematically showing an image display device according to a fourth embodiment of the present invention.

As shown in FIGS. 16 and 17 , the image display device 400 according to the fourth embodiment of the present invention includes an image panel 410 on which a flat (2D) image or a stereoscopic (3D) image is implemented, and an image panel and a backlight unit 420 providing light to 410 .

As shown in FIG. 17 , the image panel 410 may be an image cell of a liquid crystal display (LCD), and a pair of transparent substrates disposed to face each other, that is, color The filter substrate 410a and the TFT array substrate 410b may include a liquid crystal layer (not shown) injected therebetween.

The image panel 410 includes various electrodes (not shown) for controlling the arrangement of liquid crystals, for example, electrodes such as a gate line, a data line, a source electrode, a drain electrode, and a common electrode, and a black matrix (not shown). and a color filter 414 , and polarizing plates 418a and 418b may be attached to the upper and lower surfaces of the image panel 110 , respectively. In this case, the color filter 414 includes red (R), green (G), and blue (B) color filters (not shown).

And, the image display device 400 according to the fourth embodiment of the present invention may include a driving circuit (not shown) for driving the image panel. Since the image panel 410 itself is obvious to those of ordinary skill in the art to which the present invention pertains, a more detailed description thereof will be omitted.

On the other hand, the backlight unit 420 has a structure similar to that of a general edge-type backlight, but the existing light guide plate is divided in the thickness direction so that two independent light guide plates, that is, the three-dimensional light guide plate 430 and the flat light guide plate 460 are The light source array that provides light to each light guide plate, that is, the first light source 434 and the second light source 464 are also independently configured to be selectively lit according to a stereoscopic image or a planar image mode.

In particular, the backlight unit 420 provides light to the image panel 410, and when any one of a stereoscopic (3D) image and a flat (2D) image display mode is selected by the user, the surface light or the vertical direction Each of the plurality of linear lights extending to the image panel 410 is provided. In this case, the operation of the backlight unit 420 may be controlled by a driving circuit for driving the image panel 410 or may be controlled by a separately provided light source control unit.

As shown in FIGS. 16 and 17 , the backlight unit 420 includes two three-dimensional light guide plates 430 and a flat light guide plate 460 to selectively emit different types of light, and first and second selectively driven first and second light guide plates. Light sources 434 and 464 and a barrier film 440 interposed between the three-dimensional light guide plate 430 and the flat light guide plate 460 to block light leaking to the lower portion of the three-dimensional light guide plate 430; It includes an optical sheet 450 disposed under the barrier film 440 , and a reflective sheet 470 disposed under the flat light guide plate 450 disposed under the optical sheet 450 .

The three-dimensional light guide plate 430 is disposed under the image panel 410 , and the flat light guide plate 460 is disposed under the three-dimensional light guide plate 430 . In this case, the three-dimensional light guide plate 430 and the flat light guide plate 460 may be respectively formed by injection molding a transparent thermoplastic resin such as an acrylic resin, a methacrylic resin, a styrene resin, or a polycarbonate resin.

In addition, the flat light guide plate 460 has the same light profile as the light guide plate for a general planar (2D) image model, and has a uniform surface due to the optical sheet 450 disposed on it and the reflective sheet 470 disposed below it. It will act as a light source. In this case, since the three-dimensional light guide plate 430 is a transparent substrate, it can be seen that the effect on transmittance is insignificant.

The first light source 434 is disposed to correspond to the side surface of the three-dimensional light guide plate 430, that is, the first light incident surface 430a, so as to irradiate light into the interior of the three-dimensional light guide plate 430, and the second light source 464 is disposed to correspond to one side of the planar light guide plate 460 , that is, the second light incident surface 460a to irradiate light into the flat light guide plate 460 .

In addition, the first light source 434 and the second light source 464 may be formed of various types of light sources, such as a light emitted diode (LED) and a cold cathode fluorescent lamp (CCFL), respectively. In the present invention, a case in which a light emitted diode (LED) is used as a light source will be described as an example.

The first light source 434 and the second light source 464 may have a shape extending in the longitudinal direction along the side surface (ie, the light incident surface) of the three-dimensional light guide plate 430 and the flat light guide plate 460 , each of one light source may be formed, and as shown in FIG. 16 , a plurality of light sources may be arranged in a line.

The first light source 434 and the second light source 464 are configured to be separately turned on. That is, if necessary, either one of the first light source 434 and the second light source 464 may be controlled to be turned on and the other one may be turned off.

For example, when the image display device according to the fourth embodiment of the present invention operates to implement a stereoscopic (3D) image, the first light source 434 is turned on and the second light source 464 is turned off. (off), when the image display device according to the fourth embodiment of the present invention operates to implement a planar (2D) image, the first light source 434 is turned off and the second light source 464 is turns on

18 is a diagram schematically illustrating an arrangement configuration of a three-dimensional light guide plate and a barrier film of an image display device according to a fourth embodiment of the present invention.

19 is an enlarged cross-sectional view of part A of FIG. 18 , schematically illustrating a state in which a barrier film is disposed under a light exit pattern provided inside a lower surface of a three-dimensional light guide plate.

As shown in FIG. 18 , on the lower surface of the three-dimensional light guide plate 430 , a plurality of scattering patterns 432 are linearly arranged in a direction in which light emitted from the first light source 434 is spaced apart from each other. is formed to be spaced apart from each other along the cross direction, that is, the width direction of the three-dimensional light guide plate 430 to form a linear shape, and a plurality of linear light exit patterns 432 are spaced apart from each other in the longitudinal direction of the three-dimensional light guide plate 430 to be formed. can

The plurality of light exit patterns 432 may be arranged at regular intervals from each other, and the number of the plurality of light exit patterns 432 is not limited to the number shown in the drawings and may be variously changed. In particular, the plurality of light exit patterns 432 are processed in consideration of a pixel area of the display device and a viewing distance of an observer.

In addition, when the first light source 434 is turned on, the light emitting patterns 432 correspond to a light emitting area due to scattering when viewed from the front, and are non-patterned areas between the plurality of linear light emitting patterns 432 . (136) appears dark as a total internal reflection region.

Moreover, the non-patterned area 436 between the light exit patterns 432 allows a mirror reflection surface for total internal reflection to be generated. Accordingly, only portions of the light exit patterns 432 of the three-dimensional light guide plate 430 are brightly displayed.

The image display device 400 using the backlight unit according to the fourth embodiment of the present invention is formed on the lower surface of the three-dimensional light guide plate 430, rather than controlling it using a polarization component as in the conventional one to implement a stereoscopic (3D) image. Since the plurality of light exit patterns 432 are used, a separate polarizing material such as the conventional one, for example, components such as an RM lens or a polarization control film is unnecessary.

In addition, the plurality of light exit patterns 432 may be formed in any pattern capable of diffusely reflecting and scattering light. The plurality of light exit patterns 432 may be formed in various shapes, such as, for example, a concave pattern, a protruding pattern, or a dot pattern. may be At this time, in the present invention, a case in which the plurality of light exit patterns 432 are designed in the form of an intaglio dot pattern will be described as an example.

On the other hand, under the three-dimensional light guide plate 430, as shown in FIG. 19, a barrier film 440 is disposed, and in the area of the three-dimensional light guide plate 430, the light exit pattern 432 of the three-dimensional light guide plate 430 is disposed. A light blocking pattern 442 is formed in the corresponding region. In this case, the light blocking pattern 442 is formed in a region corresponding to the light exit pattern 432 , that is, in the overlapping barrier film 440 . This is because part of the light reflected from the surface of the light exit pattern 432 may leak downward, so that the light blocking pattern 442 blocks the light leaking and reflects it back toward the three-dimensional light guide plate 430 .

In addition, the transmissive region 446 between the light blocking patterns 442 allows light incident from the flat light guide plate 460 to be transmitted into the three-dimensional light guide plate 430 .

The transmission region 446 of the barrier film 440 has a light transmittance of about 80% or more, and the light blocking pattern 442 blocks light leaking from the light exit pattern 432 of the three-dimensional light guide plate 430. . In particular, the light blocking pattern 442 serves to block the light leaking from the light exit pattern 432 , and at the same time reflect the leaked light to be incident into the three-dimensional light guide plate 430 .

Accordingly, the barrier film 440 physically blocks or reduces light leaking from the stereoscopic light guide plate 430 toward the optical sheet 450 through the light blocking pattern 442, thereby Talk) can be greatly improved.

In addition, an optical sheet 450 is disposed under the barrier film 440 . In this case, the optical sheet 450 may include a diffusion sheet, a prism sheet, and a protection sheet, although not shown in the drawings.

The optical sheet 450 performs a function of irradiating the entire surface of the image panel 410 in a more uniform state to light incident by the flat light guide plate 460 and exiting the second light exit surface 460b. At this time, since the optical sheet 450 itself is obvious to those of ordinary skill in the art to which the present invention pertains, a more detailed description thereof will be omitted.

A reflective sheet 470 is disposed under the flat light guide plate 460 . The reflective sheet 470 reflects the light emitted from the lower surface of the flat light guide plate 460 among the light introduced into the flat light guide plate 460 so that it flows back into the flat light guide plate 460 , thereby reducing light loss and overall light efficiency. functions to increase

In the case of the three-dimensional light guide plate 430 of the image display device according to the fourth embodiment of the present invention having the above configuration, among the light introduced into the three-dimensional light guide plate 430, a portion where the plurality of light exit patterns 432 are not formed That is, the light reaching the non-patterned area 436 between the plurality of light exit patterns 432 that are linear, respectively, is reflected and travels back into the three-dimensional light guide plate 430 , and reaches the plurality of light exit patterns 432 . The light is scattered and emitted to the outside of the first light exit surface 430b of the three-dimensional light guide plate 430 through the light exit pattern 432 .

Accordingly, the three-dimensional light guide plate 430 emits light in the form of linear light by the plurality of linear light output patterns 434 formed to be spaced apart from each other, and the emitted light is incident on the image panel 410 .

On the other hand, in the case of the flat light guide plate 460 of the image display device 400 according to the fourth embodiment of the present invention, the light introduced from the second light source 462 facing the second light incident surface 460a is converted into a flat surface. Surface light is emitted over the entire upper surface of the light guide plate 460 , that is, the second light exit surface 460b to be emitted toward the image panel 410 . That is, the flat light guide plate 460 emits light distributed over the entire second light exit surface 460b, similar to a light guide plate used in a conventional liquid crystal display device.

To this end, a pattern for scattering light may be formed on the upper surface of the planar light guide plate 460 , and such a pattern may be implemented in various patterns such as a prism pattern and a dot pattern. In this case, the light emitted from the flat light guide plate 460 may be converted into a more uniform state by the optical sheet 450 described above and then irradiated to the image panel 410 .

In the image display device 400 according to the fourth embodiment of the present invention configured as described above, the first light source 434 and the second light source 464 are selectively controlled to be turned on, thereby displaying a stereoscopic (3D) image and A planar (2D) image may be selectively implemented.

20 is a diagram schematically illustrating a state in which a stereoscopic image is realized through a stereoscopic light guide plate of an image display device according to a fourth embodiment of the present invention.

Referring to FIG. 20 , in the image display device 400 according to the fourth embodiment of the present invention, a flat image and a stereoscopic image are selectively operated depending on whether a three-dimensional light guide plate 430 or a flat light guide plate 460 is used. This can be implemented by selectively lighting the first light source 434 and the second light source 464 . In particular, when the three-dimensional light guide plate 430 and the flat light guide plate 460 have the same size, the load capacity of the first light source 434 and the second light source 464 is the same, so there is no need to separately apply a light source driver. It can be used in common, and only the output direction can be selectively designed.

When implementing a stereoscopic image, as shown in FIG. 20 , the first light source 434 is turned on and the second light source 464 is turned off. In this case, a plurality of linear light is emitted through a plurality of linear light exit patterns 432 that are spaced apart from each other on the lower surface of the three-dimensional light guide plate 430 and formed in the longitudinal direction of the three-dimensional light guide plate, and the emitted light is the image panel 410 . is entered into

At this time, the light blocking pattern 442 provided in the barrier film 440 is located in a region corresponding to the light exit pattern 432 , that is, a portion of the overlapping barrier film 440 , and is reflected from the surface of the light exit pattern 432 . The light leaking to the lower part of the light is blocked and reflected back toward the three-dimensional light guide plate 430 to be transmitted into the three-dimensional light guide plate 430 .

Accordingly, the barrier film 440 physically blocks or reduces light leaking from the stereoscopic light guide plate 430 toward the optical sheet 450 through the light blocking pattern 442, thereby Talk) can be greatly improved.

Accordingly, the light refracted from each of the outgoing light patterns 432 passes through different pixel areas of the image panel 410 and then arrives at the viewer's left eye 482 and right eye 484 , respectively. That is, light reaching the viewer's left eye 482 passes through a path 490a indicated by a dotted line, and light reaching the viewer's right eye 484 passes through a path 490b indicated by a solid line.

Accordingly, the observer's left eye and right eye see a different image, that is, a color image is viewed in the left eye 482 and a dark image is viewed in the right eye 484 , so that separation between views occurs, and the observed image difference By this, the observer feels a stereoscopic (3D) image. In this case, pixel areas of the image panel 410 located in paths through which light emitted from the same light exit pattern 432 and reaching the left and right eyes of the observer passes are driven to display different images.

Meanwhile, when realizing a planar (2D) image, the first light source 434 is turned off and the second light source 464 is turned on. Then, the light emitted from the second light source 464 is emitted through the front surface of the second light exit surface 460b of the flat light guide plate 460 , passes through the three-dimensional light guide plate 430 and then is irradiated to the image panel 410 . .

Accordingly, the observer perceives the image displayed on the image display device as a two-dimensional (2D) flat image in the same way as in the general image display device.

At this time, a dark portion may be generated by the light blocking pattern 442 of the barrier film 440 . In this case, the dark portion may be compensated by simultaneously lighting the first light source 434 for the three-dimensional light guide plate 430 .

As described above, in the image display device using the backlight unit according to the present invention, a flat image and a stereoscopic image can be realized by selectively driving a plurality of light guide plates having a low cost and simple structure.

In addition, since the image display device using the backlight unit according to the present invention is not controlled using a polarization component as in the conventional one for realization of a flat image and a stereoscopic image, a separate polarization material, for example, an RM lens or a polarization control film and the like are unnecessary.

And, since the image display device using the backlight unit according to the present invention has a structure in which light guide plates serving as optical filters are disposed on the rear surface, substrates serving as an optical filter for view division are displayed. Since it is attached to the uppermost layer of the screen, the image quality deterioration phenomenon caused by the attached optical filter when the 2D mode is switched is eliminated.

In the image display device using the backlight unit according to the present invention, a barrier film is disposed under the three-dimensional light guide plate so that the light blocking pattern formed on the barrier film is at a position corresponding to the light output pattern of the three-dimensional light guide plate. Since light leaking from the light guide plate toward the optical sheet is physically blocked or reduced by the light blocking pattern of the barrier film, cross-talk (CT) of a stereoscopic image can be greatly improved.

Meanwhile, an image display apparatus using a backlight unit according to a fifth embodiment of the present invention will be described with reference to FIGS. 21 to 25 as follows.

21 is an exploded perspective view schematically showing an image display device according to a fifth embodiment of the present invention.

22 is a cross-sectional view schematically showing an image display device according to a fifth embodiment of the present invention.

As shown in FIGS. 21 and 22 , the image display device 500 according to the fifth embodiment of the present invention includes an image panel 510 on which a flat (2D) image or a stereoscopic (3D) image is implemented, and an image panel and a backlight unit 520 providing light to the 510 .

As shown in FIG. 22 , the image panel 510 may be an image cell of a liquid crystal display (LCD), and may be a pair of transparent substrates disposed to face each other, that is, a color filter. The substrate 510a and the TFT array substrate 510b may include a liquid crystal layer (not shown) injected therebetween.

The image panel 510 includes various electrodes (not shown) for controlling the arrangement of liquid crystals, for example, electrodes such as a gate line, a data line, a source electrode, a drain electrode, and a common electrode, and a black matrix (not shown). and a color filter 514 and the like, and polarizing plates 518a and 518b may be respectively attached to the upper and lower surfaces of the image panel 510 . In this case, the color filter 514 includes red (R), green (G), and blue (B) color filters (not shown).

And, the image display device 500 according to the fifth embodiment of the present invention may include a driving circuit (not shown) for driving the image panel. Since the image panel 510 itself is obvious to those of ordinary skill in the art to which the present invention pertains, a more detailed description thereof will be omitted.

On the other hand, the backlight unit 520 has a structure similar to that of a general edge-type backlight, but the existing light guide plate is divided in the thickness direction so that two independent light guide plates, that is, a three-dimensional light guide plate 530 and a flat light guide plate 560 , are provided. The light source array that provides light to each light guide plate, that is, the first light source 534 and the second light source 564 are also independently configured to be selectively turned on according to a stereoscopic image or a planar image mode.

In particular, the backlight unit 520 provides light to the image panel 510, and when any one of a stereoscopic (3D) image and a flat (2D) image display mode is selected by the user, the surface light or the vertical direction Each of a plurality of linear lights extending to the image panel 510 is provided. In this case, the operation of the backlight unit 520 may be controlled by a driving circuit for driving the image panel 510 or may be controlled by a separately provided light source control unit.

As shown in FIGS. 21 and 22 , the backlight unit 520 includes two three-dimensional light guide plates 530 and a flat light guide plate 560 to selectively emit different types of light, and first and second selectively driven first and second light guide plates. The light sources 534 and 564, the light blocking film 540 inserted into the lower surface of the three-dimensional light guide plate 530, the optical sheet 550 disposed under the three-dimensional light guide plate 530, and the optical sheet 550 are disposed under the optical sheet 550 and a reflective sheet 470 disposed under the planar light guide plate 560 .

The three-dimensional light guide plate 530 is disposed under the image panel 510 , and the flat light guide plate 560 is disposed under the three-dimensional light guide plate 530 . In this case, the three-dimensional light guide plate 530 and the flat light guide plate 560 may be respectively formed by injection molding a transparent thermoplastic resin such as an acrylic resin, a methacrylic resin, a styrene resin, or a polycarbonate resin.

In addition, the flat light guide plate 560 has the same light profile as a light guide plate for a general planar (2D) image model, and has a uniform surface due to the optical sheet 550 disposed on it and the reflective sheet 570 disposed below it. It will act as a light source. In this case, since the three-dimensional light guide plate 530 is a transparent substrate, it can be seen that the effect on transmittance is insignificant.

The first light source 534 is disposed to correspond to the side surface of the three-dimensional light guide plate 530, that is, the first light incident surface 530a, so as to radiate light into the interior of the three-dimensional light guide plate 530, and the second light source 564 is disposed to correspond to one side of the flat light guide plate 560 , that is, the second light incident surface 560a to irradiate light into the flat light guide plate 560 .

In addition, the first light source 534 and the second light source 564 may be formed of various types of light sources, such as a light emitted diode (LED) and a cold cathode fluorescent lamp (CCFL), respectively. In the present invention, a case in which a light emitted diode (LED) is used as a light source will be described as an example.

The first light source 534 and the second light source 564 may have a shape extending in the longitudinal direction along the side surface (ie, the light incident surface) of the three-dimensional light guide plate 530 and the flat light guide plate 560 , and each light source is one light source. may be formed, and as shown in FIG. 21 , a plurality of light sources may be arranged in a line.

The first light source 534 and the second light source 564 are configured to be separately turned on. That is, if necessary, only one of the first light source 534 and the second light source 564 may be turned on and the other one may be controlled to be off.

For example, when the image display device according to the fifth embodiment of the present invention operates to implement a stereoscopic (3D) image, the first light source 534 is turned on and the second light source 564 is turned off. (off), and when the image display device according to the fifth embodiment of the present invention operates to implement a planar (2D) image, the first light source 534 is turned off and the second light source 564 is turns on

23 is a diagram schematically illustrating an arrangement configuration of a three-dimensional light guide plate and a barrier film of an image display device according to a fifth embodiment of the present invention.

24 is an enlarged cross-sectional view of a portion B of FIG. 23 , schematically illustrating a state in which a light blocking film is formed on an outer surface of a light exit pattern provided in a three-dimensional light guide plate.

As shown in FIG. 23 , on the lower surface of the three-dimensional light guide plate 530 , a plurality of scattering patterns 532 are linearly spaced apart from each other in the traveling direction of the light emitted from the first light source 534 . is formed to be spaced apart from each other along the cross direction, that is, the width direction of the three-dimensional light guide plate 530 to form a linear shape, and a plurality of linear light exit patterns 532 are formed to be spaced apart from each other in the longitudinal direction of the three-dimensional light guide plate 530. can

The plurality of light exit patterns 532 may be arranged at regular intervals from each other, and the number of the plurality of light exit patterns 532 is not limited to the number shown in the drawings and may be variously changed. In particular, the plurality of light exit patterns 532 are processed in consideration of a pixel area of a display device and a viewing distance of an observer.

In addition, when the first light source 534 is turned on, the light exit patterns 532 correspond to emission areas due to scattering when viewed from the front, and are non-patterned areas between the plurality of linear light exit patterns 532 . (536) appears dark as a total internal reflection region.

Moreover, the non-patterned area 536 between the light exit patterns 532 allows a mirror reflection surface for total internal reflection to be generated. Accordingly, only portions of the light exit patterns 532 of the three-dimensional light guide plate 530 appear bright.

The image display device 500 using a backlight unit according to the fifth embodiment of the present invention is formed on the lower surface of the three-dimensional light guide plate 530, rather than controlling it using a polarization component as in the conventional one to implement a stereoscopic (3D) image. Since a plurality of light exit patterns 532 are used, a separate polarizing material such as the conventional one, for example, components such as an RM lens or a polarization control film is unnecessary.

In addition, the plurality of light exit patterns 532 may be formed in any pattern capable of diffusely reflecting and scattering light. The plurality of light exit patterns 532 may be formed in various shapes such as, for example, a concave pattern, a protruding pattern, or a dot pattern, and the light exit pattern 532 may be haze-treated to increase the scattering effect. may be In the present invention, a case in which the interior of the plurality of light exit patterns 532 is designed in the form of an intaglio dot pattern will be described as an example. That is, the inside of the engraved light exit pattern 532 is formed in the form of a concave groove.

Meanwhile, as shown in FIG. 24 , a light blocking film 540 is formed inside the light exit pattern 532 of the three-dimensional light guide plate 530 . In this case, the light blocking layer 540 is formed on the inner surface of the light exit pattern 532 or is inserted and filled in the light exit pattern 532 . In addition, the light blocking film 540 may be used as long as it has a non-transmissive property capable of blocking the light reflected from the lower portion of the light exit pattern 532 . The non-transmissive material means a non-transmissive material having a low visible light transmittance.

The light blocking film 540 may be formed by a masking method. This masking method includes a method of coating a light blocking material or filling the light blocking material inside the light exit pattern 532 in the form of an intaglio dot pattern. Available.

This is because a portion of the light reflected from the surface of the light exit pattern 532 may leak downward, so that the light blocking film 40 blocks the light leaking and reflects it back toward the inside of the three-dimensional light guide plate 530 . In particular, the light blocking layer 540 blocks the light leaking from the light exit pattern 532 , and at the same time reflects the leaked light back into the three-dimensional light guide plate 530 .

And, due to the continuous use of the three-dimensional light guide plate 530 , even if the three-dimensional light guide plate 530 is thermally expanded and its size is deformed, the light blocking film 460 on the outer surface of the light exit pattern 532 is on the inner surface of the light exit pattern 532 . Since there is no change in the attached state, the light leaking from the light exit pattern 532 can be effectively blocked, and the leaked light can be reflected back into the three-dimensional light guide plate 530 .

Accordingly, the light blocking film 540 physically blocks or reduces light leaking from the stereoscopic light guide plate 530 toward the optical sheet 550 , thereby greatly improving cross-talk (CT) of a stereoscopic image.

In addition, an optical sheet 550 is disposed under the three-dimensional light guide plate 530 . In this case, the optical sheet 550, although not shown in the drawings, may include a diffusion sheet, a prism sheet, and a protection sheet.

The optical sheet 550 performs a function of irradiating the entire surface of the image panel 510 in a more uniform state such that light incident by the flat light guide plate 560 and exiting the second light exit surface 560b is irradiated. At this time, since the optical sheet 550 itself is obvious to those of ordinary skill in the art to which the present invention pertains, a more detailed description thereof will be omitted.

A reflective sheet 570 is disposed under the flat light guide plate 560 . The reflective sheet 570 reflects the light emitted from the lower surface of the flat light guide plate 560 among the light introduced into the flat light guide plate 560 so that it flows back into the flat light guide plate 560 , thereby reducing light loss and overall light efficiency. functions to increase

In the case of the three-dimensional light guide plate 530 of the image display device according to the fifth embodiment of the present invention having the above configuration, among the light introduced into the three-dimensional light guide plate 530, a portion where the plurality of light exit patterns 532 are not formed That is, the light reaching the non-patterned area 536 between the plurality of light exit patterns 532 that are linear, respectively, is reflected and travels back into the three-dimensional light guide plate 530 , and reaches the plurality of light exit patterns 532 . The light is scattered and is emitted to the outside of the first light exit surface 530b of the three-dimensional light guide plate 530 through the light exit pattern 532 .

Accordingly, the three-dimensional light guide plate 530 emits light in the form of linear light by the plurality of linear light output patterns 532 formed to be spaced apart from each other, and the emitted light is incident on the image panel 510 .

On the other hand, in the case of the flat light guide plate 560 of the image display device 500 according to the fifth embodiment of the present invention, the light introduced from the second light source 562 facing the second light incident surface 560a is converted into a flat surface. Surface light is emitted over the entire upper surface of the light guide plate 560 , that is, the second light exit surface 560b to be emitted toward the image panel 510 . That is, the flat light guide plate 560 emits light distributed over the entire second light exit surface 560b, similar to a light guide plate used in a conventional liquid crystal display device.

To this end, a pattern for scattering light may be formed on the upper surface of the flat light guide plate 560 , and such a pattern may be implemented in various patterns such as a prism pattern and a dot pattern. In this case, the light emitted from the flat light guide plate 560 may be converted into a more uniform state by the optical sheet 550 described above and then irradiated to the image panel 510 .

The image display device 500 according to the fifth embodiment of the present invention configured as described above includes a stereoscopic (3D) image and A planar (2D) image may be selectively implemented.

25 is a diagram schematically illustrating a state in which a stereoscopic image is realized through a stereoscopic light guide plate of an image display device according to a fifth embodiment of the present invention.

25, in the image display device 500 according to the fifth embodiment of the present invention, a flat image and a three-dimensional image are selectively operated depending on whether a three-dimensional light guide plate 530 or a flat light guide plate 560 is used. This can be implemented by selectively lighting the first light source 534 and the second light source 564 . In particular, when the three-dimensional light guide plate 530 and the flat light guide plate 560 have the same size, the load capacity of the first light source 534 and the second light source 564 is the same, so there is no need to separately apply a light source driver. It can be used in common, and only the output direction can be selectively designed.

When implementing a stereoscopic image, as shown in FIG. 25 , the first light source 534 is turned on and the second light source 564 is turned off. In this case, a plurality of linear lights are emitted through a plurality of linear light exit patterns 532 that are spaced apart from each other on the lower surface of the three-dimensional light guide plate 530 and formed in the longitudinal direction of the three-dimensional light guide plate, and the emitted light is the image panel 510 . is entered into

At this time, the light blocking pattern 540 is located on the inner surface of the light exit pattern 532 to correspond to the light exit pattern 532, and blocks the light leaking downward among the light reflected from the surface of the light exit pattern 532. It is reflected back toward the three-dimensional light guide plate 530 so as to be transmitted into the three-dimensional light guide plate 530 .

Accordingly, the light blocking film 540 physically blocks or reduces light leaking from the stereoscopic light guide plate 530 toward the optical sheet 550 through the light exit pattern 532 , thereby performing cross-talk (CT) of a stereoscopic image. can be greatly improved.

Accordingly, the light refracted from each of the light exit patterns 532 passes through different pixel areas of the image panel 510 and then arrives at the viewer's left eye 582 and right eye 584 , respectively. That is, light reaching the observer's left eye 582 passes through a path 590a indicated by a dotted line, and light reaching the observer's right eye 584 passes through a path 590b indicated by a solid line.

Accordingly, the observer's left eye and right eye see a different image, that is, a color image is viewed in the left eye 582 and a dark image is viewed in the right eye 584 , so that separation between views occurs, and the observed image difference By this, the observer feels a stereoscopic (3D) image. In this case, pixel regions of the image panel 510 located in paths through which light emitted from the same light exit pattern 532 and reaching the left and right eyes of the observer passes are driven to display different images.

Meanwhile, when realizing a planar (2D) image, the first light source 534 is turned off and the second light source 564 is turned on. Then, the light emitted from the second light source 564 is emitted through the front surface of the second light exit surface 560b of the flat light guide plate 560 , passes through the three-dimensional light guide plate 530 and then is irradiated to the image panel 510 . .

Accordingly, the observer perceives the image displayed on the image display device as a two-dimensional (2D) flat image in the same way as in the general image display device.

As described above, in the image display device using the backlight unit according to the present invention, a flat image and a stereoscopic image can be realized by selectively driving a plurality of light guide plates having a low cost and simple structure.

In addition, since the image display device using the backlight unit according to the present invention is not controlled using a polarization component as in the conventional one for realization of a flat image and a stereoscopic image, a separate polarization material, for example, an RM lens or a polarization control film and the like are unnecessary.

And, since the image display device using the backlight unit according to the present invention has a structure in which light guide plates serving as optical filters are disposed on the rear surface, substrates serving as an optical filter for view division are displayed. Since it is attached to the uppermost layer of the screen, the image quality deterioration phenomenon caused by the attached optical filter when the 2D mode is switched is eliminated.

In the image display device using the backlight unit according to the present invention, a light blocking film is formed on the outer surface of the light exit pattern under the three-dimensional light guide plate, so that the light leaking from the stereo light guide plate toward the optical sheet through the light exit pattern is physically blocked or By being reduced, it is possible to greatly improve cross-talk (CT) of a stereoscopic image.

Those skilled in the art to which the present invention pertains will understand that the above-described present invention may be embodied in other specific forms without changing the technical details or essential characteristics thereof. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

110: image panel 120: backlight unit
130: three-dimensional light guide plate 132: first light source
134: light output pattern 132: first light source 134: second light source 140: flat light guide plate
142: second light source 160: optical sheet
170: reflective sheet 182: left eye
184: right eye

Claims (29)

a plurality of three-dimensional light guide plates having a plurality of light exit patterns on a lower surface;
an optical sheet disposed under the three-dimensional light guide plate;
a flat light guide plate provided under the optical sheet; and
and a first light source and a second light source which are provided to correspond to one side of each of the three-dimensional light guide plate and the planar light guide plate and are selectively driven;
The first light source is a backlight unit for an image display device that selectively injects light onto the plurality of three-dimensional light guide plates according to a viewing distance. The backlight unit of claim 1 , wherein the first light source is driven when a stereoscopic image is realized, and the second light source is driven when a flat image is realized. delete image panel;
a plurality of three-dimensional light guide plates provided under the image panel and having a plurality of light exit patterns on a lower surface thereof;
an optical sheet provided under the plurality of three-dimensional light guide plates;
a flat light guide plate provided under the optical sheet; and
It is provided to correspond to one side of each of the plurality of three-dimensional light guide plates and the flat light guide plate, and includes a first light source and a second light source that are selectively driven,
The first light source selectively incident light on the plurality of three-dimensional light guide plates according to a viewing distance. The image display device of claim 4 , wherein the first light source is driven when a three-dimensional image is implemented through the plurality of three-dimensional light guide plates, and the second light source is driven when a flat image is realized through the flat light guide plate. delete delete 5. The method of claim 4, wherein the plurality of three-dimensional light guide plates are composed of first, second, and third three-dimensional light guide plates stacked up and down, and the viewing distance of the user of the first three-dimensional light guide plate is D1 and the viewing distance of the user of the second three-dimensional light guide plate is D1. (D2) is D1×2, and the viewing distance D3 of the user of the third stereoscopic light guide plate is D1×3. According to claim 1,
The backlight unit for an image display device further comprising a light blocking film disposed between the plurality of three-dimensional light guide plates and the flat light guide plate to cover the entire area of the plurality of three-dimensional light guide plates. delete delete 5. The method of claim 4,
and a light blocking film provided between the plurality of three-dimensional light guide plates and the flat light guide plate to cover the entire area of the plurality of three-dimensional light guide plates. delete delete According to claim 1,
The backlight unit for an image display device further comprising a barrier film provided between the plurality of three-dimensional light guide plates and the flat light guide plate and having a plurality of light blocking patterns. delete The backlight unit of claim 15 , wherein the light blocking pattern of the barrier film is disposed at a position corresponding to the light outgoing pattern. 5. The method of claim 4,
and a barrier film provided between the plurality of three-dimensional light guide plates and the flat light guide plate and having a plurality of light blocking patterns. delete The image display device of claim 18 , wherein the light blocking pattern of the barrier film is disposed at a position corresponding to the light outgoing pattern. According to claim 1,
A backlight unit for an image display device further comprising a light blocking film provided inside the light output pattern. delete The backlight unit of claim 21 , wherein the light blocking layer is formed on an inner surface of the light exit pattern or is embedded in the entire interior of the light exit pattern. 5. The method of claim 4,
The image display device further comprising a light blocking film provided inside the light exit pattern. delete The image display device of claim 24 , wherein the light blocking layer is formed on an inner surface of the light exit pattern or is embedded in the entire interior of the light exit pattern. The image display device of claim 4 , wherein a total internal reflection region is formed between the light exit patterns of the three-dimensional light guide plate. The image display device of claim 4 , wherein the light exit pattern includes a concave pattern, a protruding pattern, and a dot pattern. The image display device of claim 4 , wherein the light output pattern is haze-processed.

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