KR20100078297A - Two-way backlight unit and two-way liquid crystal display device using the same - Google Patents

Abstract

PURPOSE: A two-way backlight unit and a two-way liquid crystal display device using the same are provide to reduce the production cost by simplifying production process. CONSTITUTION: A first diffusion plate(126a) is located in one side of a plurality of hot cathode fluorescent lamps(124). A second diffusion plate(126b) is located in the other side of a plurality of hot cathode fluorescent lamps. A first optical sheet(130a) is interposed on the first diffusion plate. A second optical sheet(130b) is interposed on a second diffusion plate. A first support main borders the edge of the first diffusion plate and the first optical sheet.

Description

Two-way backlight unit and two-way liquid crystal display device using the same}

The present invention relates to a bidirectional liquid crystal display device, and more particularly, to a bidirectional backlight unit for implementing a bidirectional liquid crystal display device.

In line with the recent information age, the display field has also been rapidly developed, and a liquid crystal display device (FPD) is a flat panel display device (FPD) having advantages of thinning, light weight, and low power consumption. LCD, plasma display panel device (PDP), electroluminescence display device (ELD), field emission display device (FED), etc. : It is rapidly replacing CRT.

Among them, liquid crystal display devices are used most actively in the fields of notebooks, monitors, TVs, etc. due to their excellent contrast ratio and high contrast ratio. These liquid crystal display devices are devices that do not have their own light emitting elements. Will require a light source.

As a result, a backlight unit having a lamp is provided on the rear side to irradiate light toward the front of the liquid crystal panel, thereby realizing an image of identifiable luminance.

1 is a cross-sectional view of a liquid crystal display using a general direct type backlight unit.

As shown in the drawing, a general liquid crystal display device includes a liquid crystal panel 10 including first and second substrates 12 and 14 and a backlight unit 20 behind the liquid crystal panel 10.

Here, the backlight unit 20 includes a reflecting plate 22, and a plurality of lamps 24 are arranged side by side on an upper surface thereof, and a diffusion plate 26 and a plurality of optical sheets (top) of the lamps 24 are arranged above. 29) is located. In this case, the plurality of optical sheets 28 includes a diffusion sheet and a light collecting sheet.

The liquid crystal panel 10 and the backlight unit 20 are modularized through the top cover 40, the support main 30, and the cover bottom 50. That is, the edges of the liquid crystal panel 10 and the backlight unit 20 are formed. The top cover 40 covering the front edge of the liquid crystal panel 10 and the cover bottom 50 covering the back surface of the backlight unit 20 in the state in which the support frame 30 having the rectangular frame shape are coupled are supported in front and rear, respectively. 30) is integrated through the medium.

On the other hand, in recent years, due to the demands of consumers, the area of the liquid crystal display device is a bidirectional liquid crystal display device that can view images in both directions from a one-way liquid crystal display device in which an image can be viewed only in one direction according to the display direction.

However, in order to implement a liquid crystal display device that does not emit light in such a manner that the image can be viewed in both directions, the liquid crystal display device should include various backlight units 20 according to the screen display method. To implement, two backlight units 20 having two liquid crystal panels 10 and emitting light to each of the two liquid crystal panels 10 should be disposed.

Therefore, such a bidirectional liquid crystal display device requires two backlight units 20, thereby causing a problem in that an additional manufacturing process and manufacturing cost increase.

In particular, a thin liquid crystal display cannot be realized due to an increase in thickness.

The present invention has been made to solve the above problems, and an object thereof is to provide a thin bidirectional liquid crystal display device.

In order to achieve the above object, the present invention provides a plurality of hot cathode fluorescent lamps; A first diffuser plate positioned at one side of the plurality of hot cathode fluorescent lamps, and a second diffuser plate positioned at the other side of the plurality of hot cathode fluorescent lamps; A first optical sheet interposed on the first diffusion plate; A second optical sheet interposed on the second diffusion plate; A first support main covering an edge of the first diffusion plate and the first optical sheet; A second support main that surrounds the edges of the second diffusion plate and the second optical sheet and is assembled with the first support main; A first liquid crystal panel positioned on the first optical sheet; A second liquid crystal panel positioned on the second optical sheet; A first top cover covering a front edge of the first liquid crystal panel and coupled to the first support main; A second liquid crystal display device may include a second top cover covering a front edge of the second liquid crystal panel and coupled to the second support main.

And a pair of side supports provided at both ends of the plurality of hot cathode fluorescent lamps, respectively, wherein the first and second support mains have a rectangular frame shape having a front surface bent in a shape of “a” and an open front surface. Light emitted from the plurality of hot cathode fluorescent lamps is incident to the first and second liquid crystal panels, respectively.

In addition, the first and second top covers may have a rectangular frame having a cross section of which the front surface is bent in a shape of “a”, and display an image implemented in the first and second liquid crystal panels through the open front surface.

The present invention also provides a plurality of hot cathode fluorescent lamps; A first diffuser plate positioned at one side of the plurality of hot cathode fluorescent lamps, and a second diffuser plate positioned at the other side of the plurality of hot cathode fluorescent lamps; A first optical sheet interposed on the first diffusion plate; Provided is a bidirectional backlight unit including a second optical sheet interposed on the second diffusion plate.

In this case, the first and second optical sheets include a diffusion sheet and at least one light collecting sheet.

As described above, by configuring a bidirectional backlight unit using a hot cathode fluorescent lamp (HCFL) as a light source according to the present invention, two backlight units were required to implement a display in the conventional bidirectional Compared with the bidirectional liquid crystal display device, there is an effect of simplifying the manufacturing process and reducing the manufacturing cost.

In particular, there is an effect that can implement a thin bi-directional liquid crystal display device compared to the conventional.

In addition, the cover bottom can be omitted, it is possible to assemble the liquid crystal display device more conveniently and simply, there is an effect that can implement the light weight and thinness of the liquid crystal display device.

In addition, in the modularization process of the liquid crystal display, it is possible to shorten the assembly time and greatly reduce the process cost.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

2 is an exploded perspective view schematically illustrating a structure of a bidirectional backlight unit according to an exemplary embodiment of the present invention.

As illustrated, the bidirectional backlight unit 120 includes a plurality of lamps 124 arranged side by side at a predetermined interval, a first diffusion plate 126a and a first diffusion plate positioned on one surface of the plurality of lamps 124. A plurality of optical sheets 130a interposed on the upper plate 126a and a plurality of optical interposed on the second diffuser plate 126b and the second diffuser plate 126b located on the other surface of the plurality of lamps 124. Sheet 130b.

In this case, the lamp 124 is a light source, and the luminance is more than three times higher than that of a common cathode fluorescent lamp or an external electrode fluorescent lamp, and is excellent in removing an afterimage of an image when a video is implemented. It is characterized by using a hot cathode fluorescent lamp (HCFL).

In addition, the first and second diffusion plates 126a and 126b disposed on both surfaces of the lamp 124 at regular intervals may be configured to have various haze characteristics according to the light uniformity. The haze values of the diffusion plates 126a and 126b may include light diffusing components such as beads, or may be configured by forming a fine pattern (not shown) on the lower surface without including the beads.

At this time, the bead has a feature that can prevent the light is partially concentrated by dispersing the light incident to the diffusion plate (126a, 126b). In addition, the diffusion plates 126a and 126b not including the beads may adjust the light scattering angle according to the shape of the fine pattern (not shown).

As a result, the light is dispersed to prevent the light from being partially concentrated.

The plurality of optical sheets 130a and 130b respectively positioned on the first and second diffuser plates 126a and 126b are to improve the quality of light emitted from the plurality of lamps 124 and to improve efficiency. And diffusion sheets 128a and 128b and at least one light collecting sheet 129a and 129b.

The diffusion sheets 128a and 128b are located directly on the diffusion plates 126a and 126b, and the light propagates toward the light collecting sheets 129a and 129b and the liquid crystal panel while dispersing light incident through the diffusion plates 126a and 126b. It adjusts the direction of light so as to widen the viewing angle and reduce the spread of bright spots, bright lines, and stains.

The diffusion sheets 128a and 128b are preferably located between the diffusion plates 126a and 126b and the light collecting sheets 129a and 129b.

In this case, in order to use the bidirectional backlight unit of the present invention, the diffusion sheets 128a and 128b are preferably provided on both sides of the plurality of lamps 124, and for this purpose, the diffusion sheets 128a and 128b may be formed. It is preferable to include the first and second diffusion sheets 128a and 128b.

The light diffused through the diffusion sheets 128a and 128b by the light collecting sheets 129a and 129b is focused in the liquid crystal panel direction. Therefore, the light collecting sheets 129a and 129b are preferably located between the diffusion sheets 128a and 128b and the liquid crystal panel. Accordingly, the light passing through the light collecting sheets 129a and 129b almost passes perpendicular to the liquid crystal panel.

In this case, the light collecting sheets 129a and 129b are arranged adjacent to each other in a band shape so that a plurality of prism acids or lenticular lenses of a shape in which the peaks and valleys are repeated are arranged in a row to protrude.

That is, the light emitted in both directions from the plurality of lamps 124 is processed to a uniform high quality while passing through the first and second diffusion plates 126a and 126b and the plurality of optical sheets 130 and then emitted in both directions. .

Here, the lamp 124 of the present invention will be described in more detail.

3 is a view schematically showing the structure of a hot cathode fluorescent lamp according to an embodiment of the present invention.

As shown, the hot cathode fluorescent lamp 124 is provided with a glass tube 201 filled with an inert discharge gas 211 made of mixed inert gas, mercury (Hg) molecules, and the like, and at both ends of the glass tube 201. First and second electrodes 203a and 203b are included.

At this time, a protective layer (not shown) and the fluorescent material 209 are coated along the inner wall of the glass tube 201.

Therefore, when a voltage is applied to the first electrode 203a, the first electrode 203a generates heat, through which heat electrons are emitted from the first electrode 203a. These hot electrons are excited by the inert discharge gases 211 filled in the glass tube 201 while moving toward the second electrode 203b, and the excited electrons emit ultraviolet rays while returning to a stable state. do.

The ultraviolet rays collide with the fluorescent material 209 to scatter and emit visible light so that the hot cathode fluorescent lamp 124 emits light.

Here, the inert discharge gas 211 may include xenon (Xe) molecules instead of mercury (Hg) molecules, and xenon (Xe) molecules are more environmentally friendly than mercury (Hg) molecules and have light emission characteristics due to ambient temperature. It has a wide range of optical properties from ultraviolet to visible light without affecting.

At this time, the lamp 124 may emit visible light or ultraviolet light by the xenon (Xe) molecule. Therefore, the hot cathode fluorescent lamp 124 of the present invention can obtain higher efficiency and luminance characteristics by simultaneously using the visible light reflected by the fluorescent material 209 and the visible light of the xenon (Xe) molecule itself.

Hereinafter, a bidirectional liquid crystal display using the bidirectional backlight unit 120 of FIG. 2 will be described in detail. Descriptions overlapping with the bidirectional backlight unit according to the present invention described above will be omitted or briefly described.

4 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention.

As shown, the bidirectional liquid crystal display device includes a bidirectional backlight unit 120 that supplies light in both directions, a first liquid crystal panel 110a and a bidirectional backlight unit 120 positioned on one surface of the bidirectional backlight unit 120. And a second liquid crystal panel 110b positioned on the other surface, first and second support mains 150a and 150b for modularizing them, and first and second top covers 140a and 140b.

Looking at each of these in detail, the first and second liquid crystal panel (110a, 110b) is a part that plays a key role in the image expression, each of the first and second substrates bonded to each other with the liquid crystal layer interposed therebetween (112a, 112b, 114a, 114b).

In this case, under the premise that the first and second liquid crystal panels 110a and 110b are active matrix systems, each of the liquid crystal panels 110 may be referred to as an array substrate. In the inner surface, a plurality of gate lines and data lines intersect to define a pixel, and a thin film transistor (TFT) is provided at each crossing point, and is connected one-to-one with a transparent pixel electrode formed in each pixel.

An inner surface of the second substrates 114a and 114b, called a color filter substrate, corresponds to each pixel, for example, a color filter of red, green, and blue colors, each of which includes a gate line, a data line, and a thin film. A black matrix is provided that covers non-display elements such as transistors.

In addition, a transparent common electrode covering these second substrates 114a and 114b is further provided.

The printed circuit boards 117a and 117b are connected along at least one edge of the first and second liquid crystal panels 110a and 110b through the connecting members 116a and 116b such as flexible circuit boards. The first and second support mains 150a and 150b are folded to be in close contact with each other.

Although not clearly shown in the drawings, the upper and lower alignment layers for determining the initial molecular alignment direction of the liquid crystal are formed at the boundary between the two substrates 112a, 112b, 114a, and 114b of the liquid crystal panels 110a and 110b and the liquid crystal layer. A seal pattern is formed along the edges of both substrates 112a, 112b, 114a, and 114b to prevent leakage of the liquid crystal layer filled therebetween.

In addition, polarizing plates (not shown) are attached to the outer surfaces of the first and second substrates 112a, 112b, 114a, and 114b, respectively.

A bidirectional backlight unit 120 is provided between the first and second liquid crystal panels 110a and 110b to supply light, and a difference in transmittance of the first and second liquid crystal panels 110a and 110b is expressed to the outside. Be sure to

The bidirectional backlight unit 120 includes a plurality of lamps 124, first and second diffuser plates 126a and 126b and a plurality of optical sheets 130a and 130b respectively positioned on both surfaces of the plurality of lamps 124. .

A pair of side supports 161a, 161b, 163a, and 163b for fixing / supporting the plurality of lamps 124 are provided at both ends of the lamp 124.

The pair of side supports 161a, 161b, 163a, and 163b includes upper side supports 161a and 163a and lower side supports 161b and 163b to fasten one end of the plurality of lamps 124 to each other at upper and lower ends thereof. .

In this case, the side supports 161a, 161b, 163a, and 163b serve to fix the lamp 124, and to uniformly space the gap between the lamp 124 and the diffusion plates 126a and 126b.

Here, the pair of support sides 161a, 161b, 163a, and 163b provided at both ends of the plurality of lamps 124 may be formed obliquely in a direction facing each other, and a groove into which the plurality of lamps 124 may be fitted. And a space in which the lamp 124 is accommodated, and the diffusion plates 126a and 126b and the plurality of optical sheets 130a and 130b are formed on the upper side of the support side 161a, 161b, 163a, and 163b. Provides the area to be seated.

Here, the lamp 124 is a light source, which is three times higher in brightness than a cold cathode fluorescent lamp or an external electrode fluorescent lamp, and is excellent in removing an afterimage of an image when a video is implemented. It is characterized by using a hot cathode fluorescent lamp (HCFL).

The plurality of optical sheets 130a and 130b positioned on the first and second diffusion plates 126a and 126b respectively include diffusion sheets 128a and 128b and at least one light collecting sheet 129a and 129b.

Accordingly, the plurality of lamps 124 emit strong ultraviolet rays, and the ultraviolet rays are absorbed by the fluorescent material to emit visible light, and the visible light is emitted from the first and second diffusion plates 126a and 126b at a wide range of angles. The first and second liquid crystal panel (110a, 110b) is processed to a uniform high quality while proceeding toward the first and second liquid crystal panel (110a, 110b) by passing through a plurality of optical sheets (130a, 130b) in turn by The first and second liquid crystal panels 110a and 110b may finally display images of high brightness.

The first and second diffuser plates 126a and 126b and the plurality of optical sheets 130a and 130b of the bidirectional backlight unit 120 are secured by edges surrounded by the first and second support mains 150a and 150b. The first and second support mains 150a and 150b are provided at upper and lower portions of the first and second diffusion plates 126a and 126b and the plurality of optical sheets 130a and 130b, respectively.

The first and second support mains 150a and 150b have a rectangular frame in which a cross section is bent in a shape to cover upper and side edges of the plurality of optical sheets 130a and 130b. The openings of the second support mains 150a and 150b are opened to allow light emitted in both directions through the plurality of optical sheets 130a and 130b to be incident to the first and second liquid crystal panels 110a and 110b, respectively.

The first and second support mains 150a and 150b are engaged with each other at the top and the bottom to define a predetermined storage space, and the plurality of lamps 124 and the first and second diffusion plates 126a and 126b are defined within the defined storage space. And a plurality of optical sheets (130a, 130b) is accommodated.

In this case, the first and second support mains 150a and 150b are formed of a synthetic resin mold and have a substantially rectangular frame shape, and the bidirectional backlight unit 120 is modularized by the first and second support mains 150a and 150b. The first and second liquid crystal panels 110a and 110b are positioned at both sides of the first and second liquid crystal panels 110a and 110b, and the first and second liquid crystal panels 110a and 110b are bidirectional backlights modularized by the first and second top covers 140a and 140b. It is modularized with the unit 120.

The first and second top covers 140a and 140b each have a rectangular frame having a cross section bent in a shape to cover the top and side edges of the first and second liquid crystal panels 110a and 110b, respectively. And open the front surfaces of the second top covers 140a and 140b to display images implemented in the first and second liquid crystal panels 110a and 110b.

Accordingly, the bi-directional liquid crystal display device of the present invention is modularized through the first and second support mains 150a and 150b and the first and second top covers 140a and 140b, thereby making the existing liquid crystal panel (110 in FIG. 2). And one plate-shaped cover bottom (50 in FIG. 1) in which the backlight unit (120 in FIG. 2) is seated, may be omitted.

Accordingly, it is possible to assemble the liquid crystal display device more conveniently and simply, and to realize the light weight and thinness of the liquid crystal display device.

In addition, in the modularization process of the liquid crystal display, assembly time and process cost may be greatly reduced.

Here, the top covers 140a and 140b may also be referred to as case tops or top cases, and the support mains 150a and 150b may also be referred to as guide panels, main supports, and mold frames.

As described above, the hot cathode fluorescent lamp 124 has a brightness that is three times higher than that of a common cathode fluorescent lamp or an external electrode fluorescent lamp, and is excellent in removing an afterimage of an image when a video is implemented. By constructing the bidirectional backlight unit 120 using, the manufacturing process is simplified and the manufacturing cost compared to the bidirectional liquid crystal display device, which required two backlight units (20 in FIG. 1) to implement the display in both directions. Can reduce the cost.

In particular, a thinner bidirectional liquid crystal display device can be realized.

In addition, since the cover bottom (50 of FIG. 1) can be omitted, it is possible to assemble the liquid crystal display device more conveniently and simply, and to realize the light weight and thinness of the liquid crystal display device.

In addition, in the modularization process of the liquid crystal display, assembly time and process cost may be greatly reduced.

The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

1 is a cross-sectional view of a liquid crystal display device using a general direct type backlight unit.

Figure 2 is an exploded perspective view schematically showing the structure of a bidirectional backlight unit according to an embodiment of the present invention.

3 is a view schematically showing the structure of a hot cathode fluorescent lamp according to an embodiment of the present invention.

4 is an exploded perspective view showing a liquid crystal display according to an embodiment of the present invention.

Claims (6)

A plurality of hot cathode fluorescent lamps; A first diffuser plate positioned at one side of the plurality of hot cathode fluorescent lamps, and a second diffuser plate positioned at the other side of the plurality of hot cathode fluorescent lamps; A first optical sheet interposed on the first diffusion plate; A second optical sheet interposed on the second diffusion plate; A first support main covering an edge of the first diffusion plate and the first optical sheet; A second support main that surrounds the edges of the second diffusion plate and the second optical sheet and is assembled with the first support main; A first liquid crystal panel positioned on the first optical sheet; A second liquid crystal panel positioned on the second optical sheet; A first top cover covering a front edge of the first liquid crystal panel and coupled to the first support main; A second top cover covering a front edge of the second liquid crystal panel and coupled to the second support main Bidirectional liquid crystal display comprising a. The method of claim 1, And a side support provided in pairs at both ends of the plurality of hot cathode fluorescent lamps. The method of claim 1, The first and second support mains have a rectangular frame in which a cross section of which the front surface is opened is bent in a "b" shape, and the light emitted from the plurality of hot cathode fluorescent lamps through the opened front surface of the first and second liquid crystals is opened. Bidirectional liquid crystal display devices respectively incident on the panel. The method of claim 1, The first and second top covers may have a rectangular frame having a cross section of which the front surface is bent in a shape of “a”, and a bidirectional liquid crystal display in which an image implemented in the first and second liquid crystal panels is displayed through the open front surface. Device. A plurality of hot cathode fluorescent lamps; A first diffuser plate positioned at one side of the plurality of hot cathode fluorescent lamps, and a second diffuser plate positioned at the other side of the plurality of hot cathode fluorescent lamps; A first optical sheet interposed on the first diffusion plate; A second optical sheet interposed on the second diffusion plate Bidirectional backlight unit comprising a. The method of claim 5, The first and second optical sheets include a diffusion sheet and at least one light collecting sheet.

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