KR20060021141A - Back-light assembly and display having the same - Google Patents

Abstract

A backlight assembly having a uniform brightness and a display device having the same are disclosed. The backlight assembly includes a light source assembly, a container, and an optical member. The light source assembly includes a plurality of point light sources for generating light having a point-shaped optical distribution. The storage container has a bottom surface and sidewalls for receiving the light source assembly. The optical member has a light reflecting portion disposed on the bottom surface and a light diffusing portion formed near the point light sources among the light reflecting portions to diffuse the light. As such, the light diffusion part for diffusing the light in the optical member may increase brightness uniformity of the light.

Description

BACK-LIGHT ASSEMBLY AND DISPLAY HAVING THE SAME}

1 is an exploded perspective view illustrating a backlight assembly according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along line I1-I2 of FIG. 1.

3 is a cross-sectional view illustrating a backlight assembly according to a second embodiment of the present invention.

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

<Explanation of symbols for the main parts of the drawings>

    100: light source assembly 200: storage container

    300: optical member 320: light diffuser

    400: light mixing member 500: diffuser plate

    600: backlight assembly 700: display panel

    800: top chassis 1000: display device

The present invention relates to a backlight assembly and a display device having the same. More particularly, the present invention relates to a backlight assembly and a display device having the same, which further improves luminance uniformity of light.

Recently, an information processing device has various forms and various functions, and processes information at a higher speed. The information processed in the information processing apparatus has an electrical signal format. Therefore, in order for the user to visually check the information processed by the information processing apparatus, display apparatuses displaying the information as an image are required.

One of the display devices, a liquid crystal display, displays an image using liquid crystal. The liquid crystal display has advantages of thinner, lighter weight, lower power consumption, and lower driving voltage than other display devices.

Since the liquid crystal of the liquid crystal display device having such an advantage is a passive element that does not emit light by itself, a backlight assembly for generating light is required to display an image from the liquid crystal display device.

Conventional backlight assemblies include light sources such as a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL), a flat fluorescent lamp (FFL), and the like, to generate light. Among these light sources, cold cathode ray tube lamps and flat panel fluorescent lamps are mainly employed in large display devices, and light emitting diodes are employed in small display devices.

The backlight assembly employing the light emitting diode as a light source includes a housing for accommodating the light emitting diode and a reflector for reflecting the light generated by the light emitting diode in order to further improve the utilization efficiency of the light generated by the light emitting diode.

However, a backlight assembly employing a conventional light emitting diode as a light source has a problem that the brightness and luminance uniformity of light are lower than those of a backlight assembly using a cold cathode ray tube lamp or the like.

Accordingly, the present invention has been made in view of such a conventional problem, and a first object of the present invention is to provide a backlight assembly having improved brightness and uniformity of light.

A second object of the present invention is to provide a display device having the backlight assembly.

The backlight assembly for achieving the first object of the present invention includes a light source assembly, a housing and an optical member. The light source assembly includes a plurality of point light sources for generating light having a point-shaped optical distribution. The storage container has a bottom surface and sidewalls for receiving the light source assembly. The optical member has a light reflecting portion disposed on the bottom surface and a light diffusing portion formed near the point light sources among the light reflecting portions to diffuse the light.

In addition, the display device for achieving the second object of the present invention includes a backlight assembly and a display panel. The backlight assembly includes a light source assembly, a container, and an optical member. The light source assembly includes a plurality of point light sources for generating light having a point-shaped optical distribution. The storage container has a bottom surface and sidewalls for receiving the light source assembly. The optical member has a light reflecting portion disposed on the bottom surface and a light diffusing portion formed near the point light sources among the light reflecting portions to diffuse the light. The display panel is disposed above the backlight assembly to change light into image light including information.

According to the present invention, the light diffusion portion for diffusing light in the optical member can be made more uniform in the luminance distribution of the light generated from the point light source.

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

Backlight assembly

Example 1

1 is a perspective view illustrating a backlight assembly according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line I1-I2 of FIG. 1.

1 and 2, the backlight assembly 600 according to the present exemplary embodiment includes a light source assembly 100, a storage container 200, and an optical member 300.

The light source assembly 100 according to the present exemplary embodiment includes a plurality of point light sources 110 for generating light having a point-shaped optical distribution, and optionally a driving substrate for applying a driving voltage to the point light sources 110. 120 may be further included.

The point light sources 110 according to the present embodiment are, for example, light emitting diodes. For example, the point light sources 110 include a red light emitting diode that generates red light, a green light emitting diode that generates green light, and a blue light emitting diode that generates blue light. Alternatively, the light emitting diode 110 according to the present embodiment may include a white light emitting diode that generates white light.

Light generated from the point light sources 110 according to the present embodiment, for example, red light generated from the red light emitting diode, green light generated from the green light emitting diode, and blue light generated from the blue light emitting diode are mixed at the top of the point light sources 110. As a result, white light is generated on the point light sources 110. In this embodiment, in order to further increase the mixing efficiency of the red light, green light and blue light, 70% to 80% of the light generated from the point light sources 110 are inclined at an angle of 20 ° to 60 ° with respect to the driving substrate 120. Is preferably released.

The driving substrate 120 applies driving power to the point light sources 110 to generate light, for example, red light, green light, and blue light, from the point light sources 110. The driving substrate 120 according to the present embodiment may further include, for example, a metal material having high thermal conductivity in order to emit heat of the point light sources 110.

In the driving substrate 120 according to the present embodiment, a plurality of point light sources 110, for example, a red light emitting diode, a green light emitting diode, and a blue light emitting diode are alternately disposed.

The storage container 200 includes a bottom surface 210 and sidewalls 220 extending or disposed at edges of the bottom surface 210 so that a storage space is formed on the bottom surface 210. An accommodation space is formed in the storage container 200 by the bottom surface 210 and the sidewalls 220, and the light source assembly 100 is accommodated in the storage space and disposed on the bottom surface 210.

The optical member 300 according to the present exemplary embodiment includes a light reflector 310 for reflecting light and a light diffuser 320 for diffusing the light.

The light reflecting unit 310 has a flat plate shape, for example, and includes openings 312 formed at positions corresponding to the point light sources 110. The light reflector 310 is disposed on each driving substrate 120, and the point light sources 110 are inserted into the openings 312 formed in the light reflector 310. The light reflector 310 reflects light toward the bottom surface 210 of the light generated from the point light sources 110.

The light reflecting unit 310 according to the present exemplary embodiment may be formed of, for example, a double layer of the reflective sheet 330 and the metal sheet 340. The reflective sheet 330 reflects most of the light generated from the point light sources 110, and the metal sheet 340 reflects the light transmitted through the reflective sheet 330 again. In this case, the reflective sheet 330 and the metal sheet 340 may be coupled to each other by, for example, an adhesive material.

The light diffusing part 320 is formed by bending a part of the light reflecting part 310, and the light diffusing part 320 is used to improve the luminance uniformity of the light generated from the point light sources 110. Diffuse light generated in the field. The light diffusion part 320 according to the present exemplary embodiment may be spaced apart from the point light sources 110 along the point light sources 110 arranged in a row on the driving substrate 120, and a plurality of light diffusion parts 320 may be formed in parallel. In the light diffusing unit 320 according to the present exemplary embodiment, the longitudinal cross section has a triangular shape, and the angle formed at the vertex of the triangular shape preferably has a range of 80 ° to 120 ° in order to increase light diffusion efficiency.                     

As such, the light diffusion part 320 formed on the optical member 300 diffuses the light generated from the point light sources 110, thereby increasing the brightness and the uniformity of the light generated from the point light sources 110.

Example 2

3 is a cross-sectional view illustrating a backlight assembly according to a second embodiment of the present invention. Since the light source assembly according to the second embodiment of the present invention has the same configuration as the light source assembly of the first embodiment described above, duplicate description thereof will be omitted, and the same reference numerals and names will be used for the same components. do.

Referring to FIG. 3, the backlight assembly 600 according to the present exemplary embodiment includes a light source assembly 100, a storage container 200, an optical member 300, an optical mixing member 400, and a diffusion plate 500. .

The storage container 200 includes a bottom surface 210 and sidewalls 220 extending or disposed from an edge of the bottom surface 210. The storage space is formed in the storage container 200 by the bottom surface 210 and the side walls 220, and the light source assembly 100 is accommodated in the storage space and disposed on the bottom surface 210. First and second steps 222 and 224 for mounting the light mixing member 400 and the diffusion plate 500 to be described later may be formed on the sidewall 220 of the storage container 200 according to the present embodiment. .

The optical member 300 according to the present exemplary embodiment includes a light reflecting unit 310 for reflecting light and a light diffusing unit 320 for diffusing the light.                     

The light reflecting unit 310 has a flat plate shape, for example, and includes openings 312 formed at positions corresponding to the point light sources 110. The light reflector 310 is disposed on each driving substrate 120, and the point light sources 110 are inserted into the opening 312 formed in the light reflector 310. The light reflector 310 reflects light toward the bottom surface 210 of the light generated from the point light sources 110. The light reflecting unit 310 according to the present exemplary embodiment may be formed of, for example, a double layer of the reflective sheet 330 and the metal sheet 340 in order to increase the reflection efficiency.

The light diffuser 320 is formed by bending a portion of the light reflector 310, and the light diffuser 320 is used to improve the luminance uniformity of the light generated from the point light sources 110. Diffuse light generated in the field. The light diffusion part 320 according to the present exemplary embodiment may be spaced apart from the point light sources 110 along the point light sources 110 arranged in a row on the driving substrate 120, and a plurality of light diffusion parts 320 may be formed in parallel. In the light diffusing unit 320 according to the present exemplary embodiment, the longitudinal cross section has a triangular shape, and the angle formed at the vertex of the triangular shape preferably has a range of 80 ° to 120 ° in order to increase light diffusion efficiency.

As such, the light diffuser 320 formed on the optical member 300 diffuses the light generated from the point light sources 110, thereby increasing the brightness and the uniformity of the light generated from the point light sources 110.

The light mixing member 400 is disposed on the light source assembly 100 and seated on the first step 222 formed in the side wall 220. The light mixing member 400 diffuses and mixes the light generated from the point light sources 110. The light mixing member 400 according to the present exemplary embodiment is disposed under the light mixing member 400 corresponding to the point light sources 110 to prevent the light generated from the point light sources 110 from being directly emitted. It may further include reflective dots 410 to further increase diffusion.

The diffusion plate 500 is seated on the second step 224 formed on the sidewall 220 with a predetermined interval spaced above the light mixing member 400. The diffusion plate 500 diffuses the light diffused from the light mixing member 400 once again to increase the brightness uniformity of the light. In addition, the light generated from the point light sources 110 through the space formed between the light mixing member 400 and the diffusion plate 500, for example, red light, green light and blue light may be mixed with each other to form white light. .

Display

Example 3

4 is an exploded perspective view illustrating a display device according to a third exemplary embodiment of the present invention. Since the backlight assembly according to the third embodiment of the present invention has the same configuration and function as the backlight assembly of the second embodiment described above, duplicate description thereof will be omitted, and the same reference numerals and names are used for the same components. Let's do it.

Referring to FIG. 4, the display apparatus 1000 according to the present exemplary embodiment includes a backlight assembly 600 generating light and a display panel 700 displaying an image using light.

The display panel 700 includes a first substrate 710, a second substrate 720, a liquid crystal layer 730, a printed circuit board 740, and a flexible circuit board 750.

The first substrate 710 includes a plurality of pixel electrodes, a thin film transistor (TFT) for applying a driving voltage to the pixel electrode, and signal lines for operating the thin film transistor.

The pixel electrode may include transparent and conductive indium tin oxide (ITO), indium zinc oxide (IZO), and amorphous indium tin oxide (a-ITO).

The second substrate 720 is disposed to face the first substrate 710. The second substrate 720 is disposed on the front surface of the second substrate 720 and is disposed at a color filter disposed at a position facing the transparent and conductive common electrode and the pixel electrode, for example, a red color filter, a green color filter, and a blue color. Include a filter.

The liquid crystal layer 730 is interposed between the first substrate 710 and the second substrate 720 and is rearranged by an electric field formed between the pixel electrode and the common electrode. The rearranged liquid crystal layer 730 adjusts the light transmittance of the light generated from the point light source 110 of the backlight assembly 600, and the light whose light transmittance is adjusted passes through the color filter to display an image.

The printed circuit board 740 includes a driving circuit therein, and the driving circuit generates a driving signal for controlling the thin film transistor TFT.

The flexible circuit board 750 electrically connects the printed circuit board 740 and the first substrate 710 to provide a driving signal generated from the printed circuit board 740 to the first substrate 710.

The display device 1000 according to the present exemplary embodiment may further include a top chassis 800.

The top chassis 800 surrounds the edge of the display panel 700 and is coupled to the side wall 220 of the storage container 200 to fix the display panel 700 to the upper portion of the backlight assembly 600.                     

The top chassis 800 prevents damage or damage to the brittle display panel 700 due to external shock and vibration, and prevents the display panel 700 from being separated from the storage container 200.

According to the present invention as described above, the light generated from the point light sources is reflected by the light diffusing portion formed in the optical member to be diffused, whereby the luminance of the light of the display device and the uniformity of the luminance may be further increased.

In the detailed description of the present invention described above with reference to the preferred embodiments of the present invention, those skilled in the art or those skilled in the art having ordinary skill in the art will be described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (13)

A light source assembly including a plurality of point light sources for generating light having a point-shaped optical distribution; A storage container having a bottom surface and sidewalls for receiving the light source assembly; And And an optical member disposed on the bottom surface, the optical member having a light reflecting portion reflecting light generated from the point light sources and a light diffusing portion formed near the point light sources to diffuse the light. The backlight assembly of claim 1, wherein the optical member has a plate shape, and the light diffusing portion has a triangular shape in longitudinal section. The backlight assembly of claim 2, wherein an angle formed at a vertex of the light diffusion part is 80 ° to 120 °. The backlight assembly of claim 1, wherein the optical member is formed of a reflective sheet and a metal sheet. The backlight assembly of claim 1, wherein the light reflector further includes openings at positions corresponding to the point light sources. The backlight assembly of claim 1, wherein the point light sources comprise one or more selected from the group consisting of a red light emitting diode, a green light emitting diode, a blue light emitting diode, and a white light emitting diode. The backlight assembly of claim 1, further comprising a light mixing member coupled to the side wall to mix the light, and a diffuser plate disposed on an upper surface of the light mixing member. A light source assembly including a plurality of point light sources for generating light having a point-shaped optical distribution, an accommodating container having a bottom surface and sidewalls for receiving the light source assembly, and disposed on the bottom surface in the point light sources A backlight assembly including an optical member having a light reflecting portion reflecting the generated light and a light diffusing portion formed near the point light sources to diffuse the light; And And a display panel disposed on the backlight assembly to change the light into image light including information. The display device of claim 8, wherein the light diffusing portion has a triangular shape in longitudinal section. The display device of claim 9, wherein an angle formed at a vertex of the light diffusion part is 80 ° to 120 °. The display device of claim 8, wherein the optical member comprises a reflective sheet and a metal sheet. The display device of claim 8, wherein the light reflection part further includes openings at positions corresponding to the point light sources. The display device of claim 8, wherein the point light sources comprise one or more selected from the group consisting of a red light emitting diode, a green light emitting diode, a blue light emitting diode, and a white light emitting diode.

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