KR20070040011A - Direct type back-light unit for lcd - Google Patents

Direct type back-light unit for lcd Download PDF

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Publication number
KR20070040011A
KR20070040011A KR1020050095239A KR20050095239A KR20070040011A KR 20070040011 A KR20070040011 A KR 20070040011A KR 1020050095239 A KR1020050095239 A KR 1020050095239A KR 20050095239 A KR20050095239 A KR 20050095239A KR 20070040011 A KR20070040011 A KR 20070040011A
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KR
South Korea
Prior art keywords
guide plate
light
light guide
formed
wedge
Prior art date
Application number
KR1020050095239A
Other languages
Korean (ko)
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KR100730306B1 (en
Inventor
여수완
Original Assignee
희성전자 주식회사
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Priority to KR1020050095239A priority Critical patent/KR100730306B1/en
Publication of KR20070040011A publication Critical patent/KR20070040011A/en
Application granted granted Critical
Publication of KR100730306B1 publication Critical patent/KR100730306B1/en

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    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133604Direct backlight with lamps
    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/133524Light-guides, e.g. fibre-optic bundles, louvered or jalousie light-guides
    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133605Direct backlight including specially adapted reflectors
    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133606Direct backlight including a specially adapted diffusing, scattering or light controlling members
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21LIGHTING
    • F21YINDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED
    • F21Y2115/00Light-generating elements of semiconductor light sources
    • F21Y2115/10Light-emitting diodes [LED]
    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics
    • G02F1/01Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating, or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333Constructional arrangements; Manufacturing methods
    • G02F1/1335Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336Illuminating devices
    • G02F1/133602Direct backlight
    • G02F1/133606Direct backlight including a specially adapted diffusing, scattering or light controlling members
    • G02F2001/133607Direct backlight including a specially adapted diffusing, scattering or light controlling members the light controlling member including light directing or refracting elements, e.g. prisms or lenses
    • GPHYSICS
    • G02OPTICS
    • G02FDEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH IS MODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THE DEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY, COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g. SWITCHING, GATING, MODULATING OR DEMODULATING; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; FREQUENCY-CHANGING; NON-LINEAR OPTICS; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F2201/00Constructional arrangements not provided for in groups G02F1/00 - G02F7/00
    • G02F2201/34Constructional arrangements not provided for in groups G02F1/00 - G02F7/00 reflector
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B20/00Energy efficient lighting technologies
    • Y02B20/16Gas discharge lamps, e.g. fluorescent lamps, high intensity discharge lamps [HID] or molecular radiators

Abstract

The present invention relates to a direct type backlight device having a structure in which a light source is disposed on a lower portion of a light guide plate having a plurality of wedge shapes at equal or variable intervals, the lower side of which is divided into a plurality of regions symmetrically about a center. A light guide plate having a wedge formed thereon, a plurality of light sources arranged on the light incident portion side of each wedge and configured of a cold cathode fluorescent lamp, a light emitting diode, and the like, and positioned above the light guide plate to collect and diffuse light of the light guide plate It is composed of the same shape as the wedge shape formed on the light guide plate and the various kinds of sheets to be formed, and a reflecting plate attached integrally to the cover bottom to reflect light upward from the lower side of the light guide plate and the light guide plate and the light source to be easily mounted, It is characterized by consisting of a cover bottom formed with a space in which the light source can be located .
In the backlight device of the present invention, the light source may be located on the light incident part side of each of the wedges formed in the light guide plate to minimize the thickness of the backlight, and to improve the brightness, and to provide light diffusion on the lower surface of the light guide plate on which the wedges are formed. By forming various patterns, it is possible to maximize the uniformity of luminance and the efficiency of the light source.
Backlight, Light Guide Panel, LCD, Wedge, Fluorescent Lamp

Description

Direct type backlight unit {Direct type Back-light unit for LCD}

1 is a cross-sectional view showing a schematic structure of a conventional edge type backlight device;

2 is a cross-sectional view showing a schematic structure of a conventional direct type backlight device;

3 is a cross-sectional view of a direct type backlight device according to an embodiment of the present invention;

4 is a cross-sectional view showing a detailed structure of a lamp reflector unit in which a light source is located according to an embodiment of the present invention;

5 is a view showing a schematic structure of a reflector and a cover bottom according to an embodiment of the present invention;

6A and 6B are cross-sectional views illustrating a schematic structure of a light guide plate according to an embodiment of the present invention;

7A and 7B are cross-sectional views illustrating a schematic structure of a light guide plate according to another embodiment of the present invention;

8a, b, and c are bottom perspective views illustrating a detailed structure of the light guide plate according to the embodiment of the present invention;

** Description of symbols for the main parts of the drawing **

110: light guide plate 111: wedge

112: light incident part 113,114,115: light diffusion pattern

120: light source 130: light diffusion sheet

140: reflector plate 141: lamp reflector

150: cover bottom

The present invention relates to a direct type backlight device, and more particularly, to a direct type backlight device having a structure in which a light source is disposed under a light guide plate having a plurality of wedge shapes formed at equal or variable intervals.

Recently, as the information society develops, the demand for display devices is increasing in various forms. Accordingly, liquid crystal display (LCD), plasma display panel (PDP), electro luminescent display (ELD), and vacuum fluorescent display (VFD) Various flat panel display devices have been researched and developed. Here, LCD is widely used as a mobile flat panel display device because of its excellent image quality, light weight, thinness, and low power consumption, and is particularly used as a laptop, computer monitor, and TV monitor. However, LCDs do not emit light by themselves and require a separate external light source to realize high quality images. Therefore, the LCD structure further includes a backlight unit as a light source of the liquid crystal display panel in addition to the liquid crystal display panel, so that the backlight unit uniformly supplies a high brightness light source to the liquid crystal display panel, thereby realizing high quality images.

In general, a backlight of a liquid crystal display device is a light source such as a cylindrical fluorescent lamp such as a Cold Cathode Fluorescent Lamp (CCFL), a Hot Cathode Fluorescent Lamp (HCFL), an External Electrode Fluorescent Lamp (EEFL), or a Light Emitting Diode (LED). Devices EL (Electro Luminescence) devices are mainly used, and are classified into edge-lighting and direct-lighting backlights according to the way light sources are arranged.

As shown in FIG. 1, the edge type backlight 10 has a light guide plate 11 that scatters and homogenizes light on the side of the fluorescent lamp 12, which is a light source of the backlight, and the fluorescent lamp 12 includes a lamp reflector 13. ) And the light emitted from the fluorescent lamp 12 is directly or reflected by the lamp reflector 13 is incident to the light guide plate (11). The reflective plate 14 is positioned below the light guide plate 11, and various sheets 15 such as a diffusion sheet, a prism sheet, and a protective sheet are positioned above the light guide plate 11. In the edge type backlight of this structure, the light emitted from the fluorescent lamp 12 is incident on the light guide plate 11, and the light guide plate 11 converts the light of the fluorescent lamp incident to the line light source into a surface light source by scattering and uniformizing the light. The reflective plate 14 reflects the light guide plate 11 upward. The diffusion sheet, the prism sheet, and the like 15 positioned on the upper side of the light guide plate 11 emit light to the liquid crystal display panel (not shown) by condensing and diffusing the light again to improve optical characteristics such as brightness and uniformity. This acts as a backlight. The edge type method distributes light to the entire surface by using a light guide plate after installing a fluorescent lamp on the outer side of the flat plate, and has a lower luminance than a direct type backlight and is difficult to use in a large screen LCD.

As shown in FIG. 2, the direct type backlight 20 includes various sheets 25 such as a diffusion sheet, a prism sheet, and a protective sheet on a diffusion plate 21 to which a diffusion agent is added to diffuse and uniformize light from a light source. ) Is stacked, and a fluorescent lamp 22 and a reflecting plate 24 are positioned at a lower side of the diffusion plate 21 to be included in the cover bottom 23 of the backlight device. The structure of the direct type backlight device 20 is that the fluorescent lamp 22 is disposed in a plane below the diffuser plate 21. Light is directly radiated by the fluorescent lamp 22 so that the edge type backlight device 10 is provided. Compared to the above, although the light efficiency is improved and can be easily applied to the large screen, the shape of the fluorescent lamp 22 may appear on the liquid crystal display panel (not shown). In order to prevent this, a sufficient space between the fluorescent lamp 22 and the diffuser plate 21 must be secured and maintained, and a diffuser must be added to the diffuser plate for uniform light distribution, thereby increasing the overall thickness of the backlight device. There is a problem that there is a limit to thinning.

The present invention is proposed to solve the above problems, the wedge shape divided into a plurality of areas on the lower surface of the light guide plate or diffuser plate is formed at equal intervals or variable intervals, the fluorescent lamp on the side of the wedge-shaped light incident portion Alternatively, it is possible to minimize the thickness of the backlight by placing the light source of the light emitting diode, and to provide a backlight device that can be easily applied to a large screen liquid crystal display because the brightness and the uniformity of the brightness and the efficiency of the light source can be maximized. The purpose.

In order to achieve the above object, the backlight device of the present invention includes a light guide plate having a wedge formed of a plurality of regions symmetrically centered on a lower side thereof, and arranged at a light incident part side of each wedge. A plurality of light sources consisting of a cold cathode fluorescent lamp, a light emitting diode, and the like, various sheets positioned above the light guide plate for condensing and diffusing the light of the light guide plate, and positioned below the light guide plate to direct the light of the light guide plate upwards. And a cover bottom on which the reflecting plate to reflect and the light guide plate, the light source, and the reflecting plate are seated.

The wedges formed on the light guide plate may be formed at the same interval or may be formed to be narrower or wider toward the center.

Various patterns, such as a lens type or a prism type, are formed on the upper side or the lower side of the light guide plate to improve light efficiency.

The reflective plate and the cover bottom may have the same shape as the wedge formed on the light guide plate, and a lamp reflector may be formed in the space where the light source is inserted to form an angle equal to the angle formed between the horizontal and the wedge. It is done.

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

3 is a cross-sectional view showing a schematic structure of a direct type backlight device according to an embodiment of the present invention.

Referring to FIG. 3, the backlight device 100 of the present invention includes a light guide plate 110 having a plurality of wedges (Wedges 111a to 111d, hereinafter referred to as 111) formed on a cover bottom 150 to which a reflector plate 140 is attached. The stacks are formed, and fluorescent lamps 120 are positioned at the light incidence portions 112 of the wedges 111 of the light guide plate 110, and various sheets 130 are stacked on the light guide plate 110. .

The light guide plate 110 serves to induce light emitted from a light source, and is a key component in a backlight device that converts a fluorescent lamp, which is a linear light source, into a surface light source, and PMMA (polymethylmethacrylate), a transparent acrylic resin, is mainly used. Used. The reflective plate 140 prevents light emitted from the fluorescent lamp from leaking to the lower portion of the light guide plate 110 to reflect the light toward the upper side of the backlight, and the various sheets 130 collect and emit light emitted from the surface of the light guide plate 110. Diffusion plays a role of equalizing luminance.

In particular, in the backlight device 100 of the present invention, the lower surface of the light guide plate 110 is formed with wedges 111 composed of a plurality of regions symmetrically about the center thereof, and light incident portions 112 of the wedges 111 are formed. The fluorescent lamp 120 is located on the side. Therefore, since the gap between the fluorescent lamp 120 and the light guide plate 110 is not required for uniform brightness, the thickness of the backlight device 100 can be minimized, and the fluorescent lamp 120 is directly under the light guide plate 110. It can be used in a large liquid crystal display device with high luminance.

In the exemplary embodiment of the present invention, a fluorescent lamp is used as the light source 120 as shown in FIG. 3, but in addition to the fluorescent lamp, an LED may be used as the light source.

In addition, the reflector plate 140 and the cover bottom 150 have the same shape as the wedges 111 formed on the light guide plate 110 in order to increase the efficiency of light to which the light guide plate 110 is easily seated and reflected upward, and the fluorescent lamp 120 ) Is provided with a lamp reflector section (see 141 in FIG. 4).

 4 shows a detailed structure of a lamp reflector in which a light source is located according to an embodiment of the present invention, and FIG. 5 shows a schematic structure of a reflector and a cover bottom.

Referring to FIG. 4, the space where the light source formed in the cover bottom and the reflector is located, that is, the upper surface of the lamp reflector 141 may be formed horizontally as shown in FIG. It may be formed to achieve a predetermined angle (θ) as shown in (b) to efficiently reflect to 112. In this case, the angle formed by the upper surface of the lamp reflector portion preferably forms the same angle θ as the wedge formed on the light guide plate.

Looking in more detail with reference to Figure 5, the reflecting plate 140 is formed integrally attached to the inner surface of the cover bottom 150. In addition, the cover bottom 150 may have a structure in which a plurality of wedge shapes 150a and 150b are integrally formed in the same manner as the shape of the wedge 111 formed on the light guide plate as shown in (a). As shown, it may be configured separately to correspond to the shape of the wedge 111 of the light guide plate.

That is, when formed to correspond to each wedge formed in the light guide plate as shown in (b) of FIG. 5, when the backlight assembly is coupled, the respective cover bottoms 150a and 150b are interconnected to form the overall cover bottom 150. Done. As shown in (b), the cover bottom is configured to be separated and combined for each wedge shape 150a and 150b, so that the cover bottom can be easily applied to a large backlight assembly.

In addition, the cover bottom 150 is formed with a lamp reflector 141 for positioning the light source 120 on the light incident portion 112 side of each wedge 111 of the light guide plate and reflecting light toward the light incident portion 112 side. The upper surface of the lamp reflector 141 is configured to be horizontal (0 °) or to have an angle equal to the angle θ formed by the wedge 111 of the light guide plate.

By configuring the cover bottom 140 in the same shape as the light guide plate 110 and integrally configuring the reflective plate 140 on the inner surface of the cover bottom 150, it is possible to minimize the thickness of the backlight, in the light guide plate 110 The light of the surface light source emitted can be efficiently reflected upward. In addition, by making the upper side of the lamp reflector 141 at the same angle as the wedge 111 of the light guide plate, the light incident efficiency of the light incident from the light source 120 to the light guide plate 110 can be increased.

6A to 8C, the backlight device of the present invention will be described in more detail.

6A and 6B illustrate a schematic cross-sectional structure of a light guide plate according to an exemplary embodiment of the present invention, and the wedges 111 divided into a plurality of areas are formed at the same distance d on the lower side of the light guide plate 110. The wedges 111 are symmetrical with respect to the center of the light guide plate 110. The wedge 111 may be configured to have a thickness that is thinner from the edge of the light guide plate 110 toward the center as shown in FIG. 6A, or may be configured to have a thicker thickness as illustrated in FIG. 6B. Each wedge 111 formed in the light guide plate 110 is one side of the light incident portion 112, a light source such as a fluorescent lamp 120 is located on the light incident portion 112 side to emit light to the light guide plate 110. .

Since the light source is located on the light incident part 112 side of the wedge 111, the light guide plate 110 for the wedge 111 in one region has a structure similar to that of the edge type backlight 10, but a plurality of wedges 111 are provided. The entire light guide plate 110 on which the light guide plate 110 is formed has a direct backlight type 20 structure.

With this structure, the backlight device 100 of the present invention can provide a thinner backlight device by drastically reducing the distance between the light guide plate 110 and the light source 120 while improving brightness and uniformity of the brightness.

7A and 7B are cross-sectional views illustrating a schematic structure of a light guide plate according to another embodiment of the present invention, in which a wedge 111 divided into a plurality of regions is provided at a lower side of the light guide plate 110 at a variable interval d 1 , d 2. )

The wedges 111 may be configured to have a narrower gap from the edge of the light guide plate 110 toward the center as shown in FIG. 7A, or may be configured to have a wider shape as shown in FIG. 7B, and the spacing d of the wedges 111. 1 and d 2 may be appropriately changed according to the pattern of the light guide plate 110 or the wedge 111 or the optical characteristics emitted to the upper side of the light guide plate 110. Although not shown, the wedges 111 having the same shape as that of FIG. 6B may be configured at variable intervals.

8A to 8C are detailed perspective views of a bottom surface of the light guide plate showing a structure in which a light diffusion pattern is formed on a surface of the light guide plate according to the embodiment of the present invention. Light diffusion patterns 113 to 115 of various shapes are formed on the lower surface of the light guide plate 110 on which the wedges 111 are formed so as to efficiently scatter and convert the light incident from the light source 120 into a surface light source having uniform luminance. It is.

Such a pattern may be formed of a prism type 113 as shown in FIG. 8A or a lens type 114 or 115 convex or concave as shown in FIG. 8B or 8C. It can be formed by various methods, such as etching, a V-groove pattern formation method, and a sandblasting method.

Although the present invention has been described in detail through specific embodiments, the present invention is not limited to the above-described embodiments and variously modified by those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention. It may be changed and implemented.

As described above, in the backlight device of the present invention, a plurality of wedge shapes are formed at equal intervals or at variable intervals on the lower side of the light guide plate, and the light sources are positioned at the light incident part side of the wedge shape, thereby minimizing the thickness of the backlight. The lower surface of the light guide plate on which the wedge is formed may form various patterns for light diffusion, thereby maximizing luminance and uniformity of luminance and efficiency of a light source.

Claims (8)

  1. A light guide plate having a wedge (Wedge) formed on a lower side and divided into a plurality of regions symmetrically about a center thereof;
    A plurality of light sources arranged on the light incidence side of each wedge;
    Various sheets positioned above the light guide plate to collect and diffuse light of the light guide plate;
    A reflection plate positioned under the light guide plate to reflect light of the light guide plate upward; And
    And a cover bottom on which the light guide plate and the light source are mounted, and an inner side of the light guide plate is attached.
  2. The backlight device of claim 1, wherein the wedges formed on the light guide plate are formed at equal intervals.
  3. The backlight device of claim 1, wherein the wedges formed on the light guide plate are formed at variable intervals, the intervals of which are narrowed or widened toward the center.
  4. The backlight device according to any one of claims 1 to 3, wherein a light diffusion pattern is formed on an upper side or a lower side of the light guide plate on which the wedge is formed to efficiently scatter light incident from the light source. .
  5. The backlight device of claim 4, wherein the pattern is formed in a lens type or a prism type.
  6. The lamp reflector of claim 1, wherein the cover bottom has the same shape as a wedge formed in the light guide plate, and a lamp reflector portion having an upper surface horizontally formed at the same angle as a wedge formed in the light guide plate is formed in the space where the light source is inserted. Backlight device, characterized in that.
  7. The backlight device of claim 6, wherein the cover bottom is formed integrally with a plurality of wedge shapes or separately formed by separating the plurality of wedge shapes.
  8. The backlight device of claim 1, wherein the light source comprises one of a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), an external electrode fluorescent lamp (EEFL), and a light emitting diode (LED).
KR1020050095239A 2005-10-11 2005-10-11 Direct type Back-light unit for LCD KR100730306B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020050095239A KR100730306B1 (en) 2005-10-11 2005-10-11 Direct type Back-light unit for LCD

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020050095239A KR100730306B1 (en) 2005-10-11 2005-10-11 Direct type Back-light unit for LCD

Publications (2)

Publication Number Publication Date
KR20070040011A true KR20070040011A (en) 2007-04-16
KR100730306B1 KR100730306B1 (en) 2007-06-19

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KR100968845B1 (en) * 2007-12-31 2010-07-09 서울반도체 주식회사 Back light unit comprising light guide panel
KR100981276B1 (en) * 2010-05-27 2010-09-10 서울반도체 주식회사 Back light unit comprising light guide panel
KR20110007319A (en) * 2009-07-16 2011-01-24 엘지디스플레이 주식회사 Light source unit and liquid crystalline display having the same
KR20110045595A (en) * 2009-10-27 2011-05-04 삼성엘이디 주식회사 Backlight Unit
KR101100923B1 (en) * 2010-06-07 2012-01-02 엘지이노텍 주식회사 light guided panel and back light unit of liquidcrystal display device having the same
US9069110B2 (en) 2009-07-31 2015-06-30 Lg Innotek Co., Ltd. Backlight unit and display device
US9158055B2 (en) 2013-01-10 2015-10-13 Samsung Display Co., Ltd. Backlight unit

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KR100843658B1 (en) * 2006-08-16 2008-07-03 김장규 LED lens, back light unit and LCD using a thereof
KR100840769B1 (en) * 2006-08-18 2008-06-24 최귀송 Backlight apparatus of liquid display apparatus
KR100968845B1 (en) * 2007-12-31 2010-07-09 서울반도체 주식회사 Back light unit comprising light guide panel
KR20110007319A (en) * 2009-07-16 2011-01-24 엘지디스플레이 주식회사 Light source unit and liquid crystalline display having the same
US9069110B2 (en) 2009-07-31 2015-06-30 Lg Innotek Co., Ltd. Backlight unit and display device
KR20110045595A (en) * 2009-10-27 2011-05-04 삼성엘이디 주식회사 Backlight Unit
US8545086B2 (en) 2009-10-27 2013-10-01 Samsung Electronics Co., Ltd. Backlight unit
US8727600B2 (en) 2009-10-27 2014-05-20 Samsung Electronics Co., Ltd. Backlight unit
KR100981276B1 (en) * 2010-05-27 2010-09-10 서울반도체 주식회사 Back light unit comprising light guide panel
KR101100923B1 (en) * 2010-06-07 2012-01-02 엘지이노텍 주식회사 light guided panel and back light unit of liquidcrystal display device having the same
US9158055B2 (en) 2013-01-10 2015-10-13 Samsung Display Co., Ltd. Backlight unit
US9846268B2 (en) 2013-01-10 2017-12-19 Samsung Display Co., Ltd. Backlight unit

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