KR20060113175A - Liquid crystal apparatus - Google Patents

Abstract

An LCD is provided to have the improved brightness by preventing loss of light. A liquid crystal panel(20) displays an image. A plurality of light sources(40) are disposed on a rear surface of the liquid crystal panel to provide light to the liquid crystal panel. A diffusion plate(33) is disposed between the light sources and the liquid crystal panel, and includes a light source receiving part(33a) and a light source isolation part(33b). The light source receiving part surrounds each one of the light sources and protrudes toward the liquid crystal panel. The light source isolation part is disposed between adjacent light source receiving parts and is depressed in a direction opposite to the liquid crystal panel. A reflection part(34) is disposed in the light source isolation part.

Description

Liquid crystal display device {LIQUID CRYSTAL APPARATUS}

1 is an exploded perspective view of a liquid crystal display according to a first embodiment of the present invention;

2 is a cross-sectional view of a liquid crystal display device according to a first embodiment of the present invention;

3 is a view for explaining an optical path according to a first embodiment of the present invention;

4 is a cross-sectional view of a liquid crystal display device according to a second embodiment of the present invention;

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

* Explanation of symbols for the main parts of the drawings

10: top chassis 20: liquid crystal panel

30: light control member 31: protective sheet

32: prism film 33, 36: diffusion plate

34, 37: diffuser reflector 35, 38: reflective sheet

40 lamp 41 LED circuit board

42: LED 50: bottom chassis

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having an improved structure of a diffusion plate.

Liquid crystal display is a device that displays a desired image by adjusting the light transmittance of liquid crystal cells arranged in a matrix form according to image signal information, and between the thin film transistor substrate, the color filter substrate, and both substrates. And a liquid crystal panel into which liquid crystal is injected. Since the liquid crystal panel of the liquid crystal display device is a non-light emitting device, a backlight unit for supplying light is disposed on the rear surface of the thin film transistor substrate. Light transmitted from the backlight unit is adjusted according to the arrangement of liquid crystals. The liquid crystal panel and the backlight unit are housed in the chassis.

The liquid crystal display further includes a driver integrated circuit for driving the liquid crystal cells and a control circuit board for controlling the driver integrated circuit.

The backlight unit includes a lamp or LED as a light source, an optical sheet for adjusting light generated from the light source, a reflector for irradiating the light reflected from the optical sheet back to the liquid crystal panel, and the like. Among the optical sheets, a diffuser plate that diffuses and uniformizes light of a light source into a liquid crystal panel is generally provided in a plate shape parallel to the liquid crystal panel regardless of the shape of the light source. Therefore, since the light emitted from the light source is not uniformly diffused, a dark portion is generated, and the light loss caused by the light passing through the diffuser plate has to pass through the diffuser plate again to be reflected back to the liquid crystal panel by the reflector plate. do.

Accordingly, an object of the present invention is to provide a liquid crystal display device having improved luminance by preventing light loss.

The above object is, according to the present invention, a liquid crystal panel for displaying an image; A plurality of light sources disposed on a rear surface of the liquid crystal panel to provide light to the liquid crystal panel; A diffusion disposed between the light source and the liquid crystal panel, the light source enclosing each light source and positioned between the light source receiving portion protruding in the direction of the liquid crystal panel and the light source receiving portion adjacent to the liquid crystal panel and recessed in the opposite direction of the liquid crystal panel; Plate; Achieved by a reflector provided in the light source isolator.

The light source is a plurality of lamps extending in one direction, and this embodiment is likely to be applied to a direct method in which the lamps are arranged on the rear surface of the liquid crystal panel. In the case of the edge system in which the lamp is arranged on at least one side of the liquid crystal panel, a reflector surrounding the lamp is provided, so that structures such as a light source accommodating part and a light source isolating part are not required.

The cross section in the transverse direction in the lamp extending direction of the light source accommodating portion may be a trapezoidal shape or a semicircle convex upward. Due to the shape of the three-dimensional light source accommodating portion, the area of the diffuser plate surrounding the lamp is increased, and the luminance of light passing through the diffuser plate is increased. In addition, by receiving the lamp inside the trapezoidal or semi-circular shape, another light control member can be arranged spaced apart from the reflective sheet.

The present invention is also applicable when the light source is an LED. In the case of using the LED as a light source, it is preferable to improve the brightness of the light by changing the structure of the diffusion plate since the light source is directly provided to the front surface of the liquid crystal panel.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

In various embodiments, like reference numerals refer to like elements, and like reference numerals refer to like elements in the first embodiment and may be omitted in other embodiments.

A liquid crystal display according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 2.

1 is an exploded perspective view of a liquid crystal display device 1 according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view of the liquid crystal display device 1 according to the first embodiment of the present invention.

The liquid crystal display device 1 is positioned on the liquid crystal panel 20, the light regulating member 30 disposed on the rear surface of the liquid crystal panel 20, the rear surface of the light regulating member 30, and provides light to the liquid crystal panel 20. A plurality of lamps 40, and a reflection sheet 35 for reflecting the light generated from the light source 40 to the liquid crystal panel 40. The liquid crystal panel 20, the light adjusting member 30, and the lamp 40 are accommodated in the upper chassis 10 and the lower chassis 50.

The liquid crystal panel 20 bonds the thin film transistor substrate 21 on which the thin film transistor is formed, the color filter substrate 22 facing the thin film transistor substrate 21, and both substrates 21 and 22 to form a cell gap. ) And a liquid crystal layer 24 positioned between the substrates 21 and 22 and the sealant 23. The liquid crystal panel 20 forms a screen by adjusting the arrangement of the liquid crystal layer 24, but since the liquid crystal panel 20 is a non-light emitting device, light must be supplied from the lamp 40 disposed on the rear surface. One side of the thin film transistor substrate 21 is provided with a driver 25 for applying a drive signal. The driver 25 includes a flexible printed circuit board (FPC. 26), a driving chip (27) mounted on the flexible printed circuit board (26), and a circuit board (PCB) connected to the other side of the flexible printed circuit board (26). 28). The driver 25 illustrated represents a chip on film (COF) method, and other known methods such as a tape carrier package (TCP) and a chip on glass (COG) may be used. In addition, the driver 25 may be formed on the thin film transistor substrate 21 during the wiring formation process.

The light adjusting member 30 disposed on the rear surface of the liquid crystal panel 20 may include a protective film 31, a prism film 32, and a diffusion plate 33.

The protection film 33 positioned at the top protects the prism film 32 that is weak to scratches.

The prism film 32 is formed with a triangular prism-shaped prism on the upper surface. The prism film 32 collects light diffused from the diffusion plate 31 in a direction perpendicular to the plane of the upper liquid crystal panel 20. Two prism films 32 are usually used, and the micro prisms formed on the prism films 32 are at an angle. The light passing through the prism film 32 is almost vertically progressed to provide a uniform luminance distribution. If necessary, a reflective polarizing film may be used together with the prism film 32, and only the reflective polarizing film may be used without the prism film 32.

The diffusion plate 33 is recessed in the opposite direction of the liquid crystal panel 20 between the light source accommodating portion 33a protruding toward the liquid crystal panel 20 so as to surround the plurality of lamps 40 and the light source accommodating portion 33a. Consists of the light source isolation portion 33b, and includes a base plate and a bead of beads formed on the base plate. In addition, the light source isolation part 33b is provided with a diffuser plate reflector 34 for reflecting light.

Since the conventional diffusion plate is provided in the form parallel to the liquid crystal panel 20 like the other light control members 31 and 32, a distance difference occurs between the lamp 40 and the diffusion plate, and due to the luminance difference of the light due to the distance difference. Dark areas have occurred. The present invention improves luminance by making the distance between the lamp 40 and the diffuser plate 33 uniform, and allowing the light generated from the lamp 40 to pass through the diffuser plate 33 of a larger area.

The light source accommodating part 33a protrudes toward the liquid crystal panel 20 so as to surround the lamp 40 as a portion where the light generated from the lamp 40 diffuses substantially into the liquid crystal panel 20, and the light source isolating part 33b. ) Is a portion which is recessed in the opposite direction of the liquid crystal panel 20 between the light source accommodating portions 33a to be in contact with the reflective sheet 35 positioned on the rear surface of the lamp 40.

The cross section in the transverse direction of the lamp 40 extending direction of the light source accommodating portion 33a is a trapezoidal shape that is convex upward as shown in FIG. 2. The lamp 40 is located in this convex shape, and the light generated from the lamp 40 is diffused through the surface of the light source accommodating portion 33a. In addition, the convex light source receiving portion 33a may support the prism film 32 and the protective sheet 31 spaced apart from the lamp 40 at the upper portion of the lamp 40.

The diffuser reflector 34 is positioned in the light source isolation unit 33b, and the light that passes through the diffuser plate 33 or the light that passes through the diffuser plate 33 and is reflected from the prism film 32 or the like is returned to the liquid crystal panel. Reflect in the (20) direction. That is, most of the light passing through the diffusion plate 33 is irradiated to the liquid crystal panel 20, but part of the light is reflected back toward the diffusion plate 33. Some of the reflected light is re-reflected through the reflective sheet 35. In this case, a loss of light occurs in the process of being reflected back through the diffuser plate 33, which causes a problem of decreasing luminance. Therefore, by adhering a sheet of the same material as the reflective sheet 35 to the light source isolation part 33b of the diffuser plate 33 or by applying a material capable of reflecting light, a larger amount of light can be efficiently reflected. have. Due to the three-dimensional shape of the light source accommodating portion 33a, light diffused to the side exists, and the light is reflected to the liquid crystal panel 20 through the reflective sheet 35 without having to pass through the diffuser plate 33 again. When the light passing through the diffuser plate 33 is reflected back by the reflecting sheet 35, the reflectance is about 60%, but when the light is directly reflected by the diffuser reflector 34 without passing through the diffuser plate 33, the reflectance is reflected. This is about 99%, which is very effective for improving luminance.

The plurality of lamps 40 are disposed on the rear surface of the light adjusting member 30 to provide light to the liquid crystal panel 20. In the backlight unit, a lamp 40 is disposed on the entire rear surface of the liquid crystal panel 20 to directly irradiate light to the liquid crystal panel 20, and a light guide plate is provided on the rear surface of the liquid crystal panel 20. Arranged on at least one side of the light guide plate, it is divided into an edge method for irradiating light to the liquid crystal panel 20 through the light guide plate. This embodiment is applied to a direct method in which a plurality of lamps 40 are positioned over the entire rear surface of the liquid crystal panel 20. Cold Cathode Fluorescent Lamp (CCFL) or External Electrode Fluorescent Lamp (EEFL), which consists of the lamp body and the external electrode for powering the lamp body, is used as a light source. Sometimes used as a light source for a display device

Reflective sheet 35 reflects the light transmitted in the opposite direction of the liquid crystal panel 20 through the light adjusting member 30 back to the light adjusting member 30, thereby reducing the loss of light and at the light adjusting member 30 It contributes to improving the uniformity of the light transmitted in the liquid crystal panel 20 direction. The reflective sheet 35 may be made of polyethylene terephthalate (PET) or polycarbonate (PC).

The bottom chassis 50 accommodates the lamp 40 and the light adjusting member 30. According to another embodiment, a reflective sheet 35 may be attached to an inner wall surface of the bottom chassis 50 to accommodate the lamp 40, and thus may be integrally provided. As such, the reflective sheet 35 is integrally provided in close contact with the inner wall surface of the bottom chassis 50 so that a separate structure for fixing the reflective sheet 35 is not required, and the reflection efficiency of light can be improved.

The top chassis 10 supports the front edge of the liquid crystal panel 20 to form an image, and accommodates the bottom chassis 50 to fix the liquid crystal panel 20, the lamp 40, and the light adjusting member 30. Play a role.

3 is a view for explaining the optical path according to the first embodiment of the present invention, as shown in the light generated from the lamp 40 is a liquid crystal by the diffuser plate 33 and the diffuser reflector 34 It is directed in the panel 20 direction. Most of the light generated by the lamp 40 is diffused through the diffusion plate 33 to the liquid crystal panel 20. A part of the light is reflected back toward the diffuser plate 33 and is reflected back from the diffuser reflector 34, and the light passing through the side of the light source accommodating part 33a is also passed through the diffuser reflector 34. Will be reflected back to The luminance is increased by increasing the light reflected by the diffuser plate 34 to the liquid crystal panel 20 without passing through the diffuser plate 33 again.

FIG. 4 is a cross-sectional view of the liquid crystal display device 1 according to the second embodiment of the present invention, except for the shape of the light source accommodating portion 33c of the diffuser plate 33.

As shown, the light source accommodating portion 33c has a semicircular shape in which its cross section is convex upward. Since the distance between the lamp 40 and the diffusion plate 33c is constant, the distance that the light generated from the lamp 40 reaches the diffusion plate 33 is constant. The cross-sectional shape of the light source accommodating portion 33c has a large area covering the lamp 40, so that the maximum amount of light is preferably designed to diffuse in the direction of the liquid crystal panel 20. It is possible to be modified.

5 is an exploded perspective view of the liquid crystal display device 1 according to the third exemplary embodiment of the present invention, except for the shapes of the LED circuit board 41 and the diffusion plate 36 on which the LEDs 42 as the light source are formed. Since it is the same as the liquid crystal display device 1 shown in FIG. 1, duplicated description is omitted.

The LED circuit board 41 is located over the entire rear surface of the liquid crystal panel 20. The LED 42 is mounted on the LED circuit board 41, and the LED 42 is also disposed over the entire rear surface of the liquid crystal panel 20. The LED 42 includes LEDs 42 emitting red, blue, and green colors, respectively, and light of each color is mixed to supply white light to the liquid crystal panel 20. The method of arranging the LEDs 42 of each color is not limited.

The reflective sheet 38 is provided on the LED circuit board 41 on which the LED 42 is not formed. The reflective sheet 38 is provided with an LED receiving hole 38a corresponding to the arrangement of the LED 42, and the LED 42 is housed in the LED receiving hole 38a. The reflective sheet 38 serves to reflect light incident to the lower part to supply the diffuser plate 36, and may be provided to be thicker so that deformation does not occur due to strong heat generated from the LED 42.

The diffuser plate 36 is formed with a convex protrusion that individually surrounds the LED which is a point light source, and a diffuser reflector 37 is provided between the protrusions. The diffuser reflector 37 may have a semicircular shape as shown, and may be deformed into a trapezoidal shape protruding upward as shown in the light source accommodating part 33a of FIG. 2.

The diffusion plate 36 may have a light blocking pattern made of a material having a low transmittance on a portion of the diffusion plate 36 to which the light of the LED 42 is most strongly supplied so that the arrangement of the LEDs 42 is not recognized. have. In some cases, a light guide plate and a diffusion film may be used instead of the diffusion plate 36.

Although some embodiments of the invention have been shown and described, one of ordinary skill in the art will appreciate that the light transmittance can be improved by modifying the structure of the diffuser without departing from the principles or spirit of the invention. It will be appreciated that this embodiment may be modified. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

As described above, according to the present invention, a liquid crystal display device having improved luminance by preventing light loss is provided.

Claims (5)

A liquid crystal panel which displays an image; A plurality of light sources disposed on a rear surface of the liquid crystal panel to provide light to the liquid crystal panel; A diffusion disposed between the light source and the liquid crystal panel, the light source enclosing each light source and positioned between the light source receiving portion protruding in the direction of the liquid crystal panel and the light source receiving portion adjacent to the liquid crystal panel and recessed in the opposite direction of the liquid crystal panel; Plate; And a reflector provided in the light source isolator. The method of claim 1, And the light source is a plurality of lamps extending in one direction. The method of claim 2, And a cross section in a transverse direction in the lamp extending direction of the light source accommodating portion has a trapezoidal shape that is convex upward. The method of claim 2, And a cross section in a transverse direction in the lamp extending direction of the light source accommodating portion is a semicircular convex upward. The method of claim 1, The light source is a liquid crystal display, characterized in that the LED.

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