KR20100056196A - Back light unit and liquid crystal display device - Google Patents

Abstract

PURPOSE: A backlight unit and a liquid crystal display device are provided to remove a noise problem due to humming noise. CONSTITUTION: A plurality of sockets(173) is located on a circuit board. Lamps(174) are inserted into the sockets. A cover bottom(180) comprises a coupling part and a guide part. The coupling part fixes the circuit board. The guide part guides the fixing of the coupling part.

Description

Back light unit and liquid crystal display device

Embodiments of the present invention relate to a backlight unit and a liquid crystal display.

With the development of information technology, the market for a display device, which is a connection medium between a user and information, is growing. Accordingly, flat panel displays (FPDs), such as liquid crystal displays (LCDs), organic light emitting diodes (OLEDs), and plasma display panels (PDPs), may be used. Usage is increasing. Among them, a liquid crystal display device capable of realizing high resolution and capable of large size as well as small size is widely used.

Here, the liquid crystal display device is classified into a light receiving display device. Such a liquid crystal display may display an image by receiving a light source from a backlight unit disposed under the liquid crystal panel.

The LCD includes a liquid crystal panel including a color filter substrate and a transistor array substrate, and a backlight unit for providing light to the liquid crystal panel. The liquid crystal layer is formed between the color filter substrate and the transistor array substrate included in the liquid crystal panel. The backlight unit includes a lamp for providing light to the liquid crystal panel and an optical sheet for guiding light emitted from the lamp to the liquid crystal panel.

Meanwhile, in the conventional backlight unit, a circuit board is shaken due to a structural defect in which a circuit board into which a lamp is inserted is not stably fixed to a cover bottom, which is called a humming noise. .

Embodiments of the present invention for solving the above problems of the background technology, by stably fixing the circuit board with a lamp to the cover bottom, so as to solve the so-called humming noise of the circuit board shakes, as well as to reduce the cost It is to provide a backlight unit and a liquid crystal display device.

Embodiments of the present invention as a means for solving the above problems, the liquid crystal display panel; And a backlight unit providing light to the liquid crystal display panel, wherein the backlight unit includes a circuit board, a plurality of sockets positioned on the circuit board, a lamp inserted into and fixed to the plurality of sockets, and a fastening to fix the circuit board. The present invention provides a liquid crystal display device including a cover bottom including a guide part to help fix the part and the fastening part.

The guide part may include a protrusion that protrudes from the cover bottom to an upper portion of the circuit board and a bent portion that is bent to press the upper surface of the circuit board.

The guide part may be located in an area adjacent to the circuit board so as to press an area opposite to an area in which the plurality of sockets are located.

The circuit board may include a patterned hole patterned in an area adjacent to the fastening part, and the guide part may include a protrusion protruding from the cover bottom to an upper portion of the circuit board so as to fit into the pattern hole, and a bent portion bent to press the circuit board. .

The fastening part may include a support surface protruding from the cover bottom to support the circuit board, and a support hole formed to fix the circuit board and the cover bottom by screws inserted through holes formed in the circuit board.

On the other hand, an embodiment of the present invention in another aspect is a circuit board, a plurality of sockets located on the circuit board, a lamp that is inserted and fixed to the plurality of sockets, the fastening portion for fixing the circuit board and the guide to help fix the fastening portion Provided is a backlight unit including a cover bottom including a portion.

The guide part may include a protrusion that protrudes from the cover bottom to an upper portion of the circuit board and a bent portion that is bent to press the upper surface of the circuit board.

The guide part may be located in an area adjacent to the circuit board so as to press an area opposite to an area in which the plurality of sockets are located.

The circuit board may include a patterned hole patterned in an area adjacent to the fastening part, and the guide part may include a protrusion protruding from the cover bottom to an upper portion of the circuit board so as to fit into the pattern hole, and a bent portion bent to press the circuit board. .

The fastening part may include a support surface protruding from the cover bottom to support the circuit board, and a support hole formed to fix the circuit board and the cover bottom by screws inserted through holes formed in the circuit board.

Embodiments of the present invention provide a backlight unit and a liquid crystal display device that can stably fix a circuit board on which a lamp is formed on a cover bottom, thereby eliminating noise problems caused by humming noise, and reducing costs. It is effective.

Hereinafter, with reference to the accompanying drawings, the specific content for the practice of the present invention will be described.

1 is an exploded perspective view of a liquid crystal display device.

As illustrated in FIG. 1, the liquid crystal display device may include a liquid crystal panel 130, a driver 189, and a backlight unit 179.

The liquid crystal panel 130 may have a structure in which the first substrate 110 having the thin film transistor array and the second substrate 120 having the color filter are bonded to each other with the liquid crystal layer interposed therebetween. In the liquid crystal panel 130, subpixels driven independently by a thin film transistor are arranged in a matrix form, and a difference between a common voltage supplied to each common pixel and a data signal supplied to a pixel electrode connected to the thin film transistor is provided. The image can be displayed by controlling the liquid crystal array in accordance with the voltage to adjust the light transmittance.

The backlight unit 179 includes a cover bottom 180, a circuit board 172, a plurality of sockets 173, a lamp 174, a diffusion plate 175, a diffusion sheet 176, an optical sheet 177, and a protective sheet. 178, and the like. Here, in the case of the lamp 174, a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), and an external electrode fluorescent lamp (External electrode) are inserted into and fixed to the plurality of sockets 173. Electrode Fluorescent Lamp (EEFL)) may be used, but is not limited thereto. The optical sheet 177 may be a sheet such as a prism, a lenticular lens, a micro lens, or the like, but is not limited thereto.

The driver 189 includes a plurality of film circuits 140 mounted on a driving chip 150 for driving data lines and gate lines of the liquid crystal panel 130, respectively, and connected to one side of the first substrate 110. The printed circuit board 188 may be connected to the other side of the first substrate 110. The film circuit 140 mounting the driving chip 150 may be positioned in a chip on film (COF) or tape carrier package (TCP) method. However, the driving chip 150 may be directly mounted on the first substrate 110 by a chip on glass (COG) method, or may be formed and embedded on the first substrate 110 in a thin film transistor forming process.

The liquid crystal panel 130 and the backlight unit 179 displaying the abnormal image may be accommodated by the cover top 190 and the cover bottom 180. The cover top 190 may accommodate the liquid crystal panel 130, and the cover bottom 170 may receive the backlight unit 179. Meanwhile, the liquid crystal panel 130 may be positioned at a predetermined interval on the backlight unit 179. The liquid crystal panel 130 and the backlight unit 179 may be fixed and protected by the cover top 190 fastened to the cover bottom 180. Here, an opening for exposing the image display area of the liquid crystal panel 130 may be provided on the upper surface of the cover top 190.

The liquid crystal panel 130 described above may display an image on each subpixel according to a scan signal supplied through the gate lines and a data voltage supplied through the data lines. The scan signal may be, but is not limited to, a pulse signal in which the gate high voltage supplied for one horizontal time and the gate low voltage supplied for the remaining time are alternated.

The thin film transistor included in the subpixel may be turned on when a gate high voltage is supplied from the gate lines, and may supply a data voltage applied from the data lines to the liquid crystal layer. Accordingly, when the thin film transistor of each subpixel is turned on and the data voltage is applied to the pixel electrode, the liquid crystal display may display an image while charging the difference voltage between the data voltage and the common voltage to the liquid crystal layer.

On the contrary, when the gate low voltage is supplied from the gate lines, the thin film transistor may be turned off and the data voltage charged in the liquid crystal layer may be maintained by the storage capacitor for one frame period. Meanwhile, the liquid crystal panel 130 may repeat different operations according to the scan signal supplied through the gate lines.

Hereinafter, the liquid crystal panel will be described in more detail.

2 is a cross-sectional view of the liquid crystal panel.

Referring to FIG. 2, the liquid crystal panel may have a bonded structure with the liquid crystal layer 125 positioned between the first substrate 110 and the second substrate 120 interposed therebetween.

The gate 111 may be located on one surface of the first substrate 110. The gate 111 is any one selected from the group consisting of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu). It may be made of one or an alloy thereof. In addition, the gate 111 may include molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), and copper (Cu). It may be a multilayer made of any one or alloys thereof. In addition, the gate 111 may be a double layer of molybdenum / aluminum-neodymium or molybdenum / aluminum.

The first insulating layer 112 may be positioned on the gate 111. The first insulating layer 112 may be a silicon oxide layer (SiOx), a silicon nitride layer (SiNx), or a multilayer thereof, but is not limited thereto.

An active layer 114a positioned in a region corresponding to the gate 111 may be positioned on the first insulating layer 112, and an ohmic contact layer 114b lowering a contact resistance may be disposed in the active layer 114a. have. In addition, a data pad 113 to which a data voltage is supplied may be positioned on the first insulating layer 112, but is not limited thereto.

The source 115 and the drain 116 may be positioned on the active layer 114a. The source 115 and the drain 116 may be formed of a single layer or multiple layers. When the source 115 and the drain 116 are a single layer, molybdenum (Mo), aluminum (Al), chromium (Cr), and gold may be used. (Au), titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu) may be made of any one or an alloy thereof. In addition, when the source 115 and the drain 116 are multiple layers, the double layer of molybdenum / aluminum-neodymium and the triple layer of molybdenum / aluminum / molybdenum or molybdenum / aluminum-neodymium / molybdenum may be used.

The second insulating layer 117 may be positioned on the source 115 and the drain 116. The second insulating layer 117 may be a silicon oxide film SiOx, a silicon nitride film SiNx, or a multilayer thereof, but is not limited thereto. The second insulating layer 117 may be a passivation layer.

The pixel electrode 118 connected to the source 115 or the drain 116 may be positioned on the second insulating layer 117. The pixel electrode 118 may be one of indium tin oxide (ITO), indium zinc oxide (IZO), or zinc oxide (ZnO).

The common electrode (not shown) may be positioned on the second insulating layer 117 to face the pixel electrode 118. The common electrode may be located on the first substrate 110 or the second substrate 120 according to the driving method.

A spacer 119 may be positioned on the first substrate 110 to maintain a cell gap with the second substrate 120 on the second insulating layer 117 corresponding to the source 115 and the drain 116. have.

The black matrix 121 may be positioned on one surface of the second substrate 120. The black matrix 121 is a non-display area and may be positioned to correspond to the area where the spacer 119 is located. The black matrix 121 is made of a photosensitive organic material to which a black pigment is added, and as the black pigment, carbon black or titanium oxide may be used.

The color filters 120R, 120G, and 120B may be positioned between the black matrices 121. The color filters 120R, 120G, and 120B may have other colors as well as red (120R), green (120G), and blue (120B).

The overcoating layer 122 may be positioned on the black matrix 121 and the color filters 120R, 120G, and 120B. The overcoating layer 122 may be omitted depending on the structure of the second substrate 120 having the black matrix 121 and the color filters 120R, 120G, and 120B.

2 is only for the understanding of the liquid crystal panel, the liquid crystal panel according to the exemplary embodiment of the present invention is not limited thereto.

Hereinafter, the backlight unit will be described.

First Embodiment

3 is a plan view of a part of the backlight unit according to the first embodiment of the present invention.

Referring to FIG. 3, the backlight unit includes a circuit board 172, a plurality of sockets 173 positioned on the circuit board 172, a plurality of lamps 174 inserted into and fixed to the plurality of sockets 173, and The cover bottom 180 may include a fastening part 184 to fix the circuit board 172 and a guide part 182 to help fix the fastening part 184.

The circuit board 172 may include a plurality of sockets 173 positioned on the cover bottom 180 and fixing the plurality of lamps 174. Although not shown, the circuit board 172 has wirings electrically connected to an inverter for supplying power to the plurality of lamps 174 inserted into and fixed to the plurality of sockets 173. The circuit board 172 is formed on one side and the other side so that the plurality of lamps 174 arranged on the cover bottom 180 is inserted and fixed.

The cover bottom 180 may include a fastening part 184 and a guide part 182 for fixing the circuit board 172 positioned on the cover bottom 180. Here, the fastening part 184 may serve to fix the circuit board 172 to the cover bottom 180, and the guide part 182 is fixed to the cover bottom 180 by the fastening part 184. It may serve to prevent lifting or incomplete fixing of the circuit board 172. The fastening part 184 and the guide part 182 formed on the cover bottom 180 may be formed by a process such as pressing or welding when the cover bottom 180 is manufactured, but is not limited thereto. In addition, the position of the fastening part 184 and the guide part 182 is not limited to drawing.

Hereinafter, the backlight unit according to the first embodiment of the present invention will be described in more detail with reference to a cross-sectional view of the region X-X of FIG. 3.

4 is a cross-sectional view according to the first embodiment of the present invention.

Referring to FIG. 4, the fastening part 184 is a screw inserted through the support surface 184a protruding from the cover bottom 180 and the hole H1 formed in the circuit board 172 to support the circuit board 172. A support hole 184b formed to fix the circuit board 172 and the cover bottom 180 by 185 may be included.

The guide part 182 may include a protrusion 182a protruding from the cover bottom 180 to an upper portion of the circuit board 172 and a bent part 182b bent to press the upper surface of the circuit board 172. . The guide part 182 may be located in an area adjacent to the circuit board 172 so as to press an area opposite to an area in which the plurality of sockets 173 are located.

Second Embodiment

5 is a partial plan view illustrating a backlight unit according to a second exemplary embodiment of the present invention.

Referring to FIG. 5, the backlight unit includes a circuit board 272, a plurality of sockets 273 positioned on the circuit board 272, a plurality of lamps 274 inserted into and fixed to the plurality of sockets 273, and The cover bottom 280 may include a fastening part 284 to fix the circuit board 272 and a guide part 282 to help fix the fastening part 284.

The circuit board 272 may include a plurality of sockets 273 positioned on the cover bottom 280 and fixing the plurality of lamps 274. Although not shown, the circuit board 272 has wirings electrically connected to an inverter for supplying power to the plurality of lamps 274 inserted into and fixed to the plurality of sockets 273. The circuit board 272 is formed on one side and the other side so that the plurality of lamps 274 arranged on the cover bottom 280 is inserted and fixed.

The cover bottom 280 may include a fastening part 284 and a guide part 282 for fixing the circuit board 272 positioned on the cover bottom 280. Here, the fastening part 284 may serve to fix the circuit board 272 to the cover bottom 280, and the guide part 282 is a circuit fixed to the cover bottom 280 by the fastening part 284. It may serve to prevent lifting or incomplete fixation of the substrate 272. The fastening part 284 and the guide part 282 formed on the cover bottom 280 may be formed by a process such as pressing or welding when the cover bottom 280 is manufactured, but is not limited thereto. In addition, the position of the fastening part 284 and the guide part 282 is not limited to drawing.

Hereinafter, the backlight unit according to the second exemplary embodiment of the present invention will be described in detail with reference to the sectional view of the Y-Y region of FIG. 5.

6 is a cross-sectional view according to a second embodiment of the present invention.

Referring to FIG. 6, the fastening part 284 is a screw inserted through the support surface 284a protruding from the cover bottom 280 and the hole H1 formed in the circuit board 272 to support the circuit board 272. A support hole 284b formed to fix the circuit board 272 and the cover bottom 280 by the reference numeral 285 may be included.

The circuit board 272 includes a pattern hole H2 patterned in an area adjacent to the fastening part 284, and the guide part 282 is formed from the cover bottom 280 so as to fit in the pattern hole H2. The protrusion 282a protruding to the upper portion of the 272 and the bent portion 282b bent to press the circuit board 272 may be included.

As described above, the fastening parts 184 and 284 for fixing the circuit boards 172 and 272 to the cover bottoms 180 and 280 and the guide part 182 for fixing the fastening parts 184 and 284. , 282, the circuit boards 172 and 272 can be stably fixed to the cover bottoms 180 and 280 so that the circuit boards 172 and 272 are shaken, so-called humming noise. The problem can be solved.

In addition, when the circuit boards 172 and 272 are fixed to the cover bottoms 180 and 280 as in the embodiment of the present light emission, there is an advantage that the cost can be reduced compared to the conventional method. Conventionally, a method of using an insulation sheet or a gap pad has been proposed to solve the problem of humming noise. In the case of the insulating sheet method, since the inverter outputs a high voltage, the cost is increased because an advanced sheet must be used. In the case of the gap pad method, there is a problem in that the noise increases as well as the cost increases due to the change in the thickness of the cap pad due to the internal temperature increase according to the lighting time of the liquid crystal display. However, in the embodiment of the present invention, since the circuit board is stably fixed to the structure formed on the cover bottom, the cost can be reduced compared to the conventional methods.

Therefore, an embodiment of the present invention provides a backlight unit and a liquid crystal display device that can stably fix a circuit board on which a lamp is formed on a cover bottom, thereby eliminating the noise problem caused by the humming noise and reducing the cost. It is effective to provide.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood that the invention may be practiced. Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all aspects. In addition, the scope of the present invention is shown by the claims below, rather than the above detailed description. Also, it is to be construed that all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention.

1 is an exploded perspective view of a liquid crystal display device;

2 is a cross-sectional view of the liquid crystal panel.

3 is a partial plan view illustrating a backlight unit according to a first embodiment of the present invention.

4 is a cross-sectional view according to the first embodiment of the present invention.

5 is a partial plan view illustrating a backlight unit according to a second exemplary embodiment of the present invention.

6 is a cross-sectional view according to a second embodiment of the present invention.

<Explanation of symbols on main parts of the drawings>

110: first substrate 120: second substrate

130: liquid crystal panel 179: backlight unit

172, 272: circuit boards 173, 273: a plurality of sockets

174, 274: Multiple lamps 180, 280: Cover bottom

182 and 282 guide parts 184 and 284 fastening parts

Claims (10)

A liquid crystal display panel; And It includes a backlight unit for providing light to the liquid crystal display panel, The backlight unit, Circuit board, A plurality of sockets positioned on the circuit board; A plurality of lamps inserted into and fixed to the plurality of sockets, And a cover bottom including a fastening part to fix the circuit board and a guide part to help fix the fastening part. The method of claim 1, The guide unit, And a bent portion protruding from the cover bottom to an upper portion of the circuit board and bent to press an upper surface of the circuit board. The method of claim 2, The guide unit, To press an area opposite to an area where the plurality of sockets are located And a liquid crystal display device positioned in an area adjacent to the circuit board. The method of claim 1, The circuit board includes a pattern hole patterned in an area adjacent to the fastening part. And the guide part includes a protruding portion protruding from the cover bottom to an upper portion of the circuit board so as to be inserted into the pattern hole, and a bent portion bent to press the circuit board. The method of claim 1, The fastening portion, And a support hole protruding from the cover bottom to support the circuit board, and a support hole fixed to the circuit board and the cover bottom by screws inserted through holes formed in the circuit board. Circuit board, A plurality of sockets positioned on the circuit board; A plurality of lamps inserted into and fixed to the plurality of sockets, And a cover bottom including a fastening part to fix the circuit board and a guide part to help fix the fastening part. The method of claim 6, The guide unit, And a protrusion that protrudes from the cover bottom to an upper portion of the circuit board and a bent portion that is bent to press an upper surface of the circuit board. The method of claim 7, wherein The guide unit, And an area adjacent to the circuit board so as to press an area opposite to an area where the plurality of sockets are located. The method of claim 6, The circuit board includes a pattern hole patterned in an area adjacent to the fastening part. The guide unit includes a protrusion protruding from the cover bottom to an upper portion of the circuit board so as to fit in the pattern hole and a bent portion bent to press the circuit board. The method of claim 6, The fastening portion, And a support hole formed so that the circuit board and the cover bottom are fixed by a support surface protruding from the cover bottom to support the circuit board and a screw inserted through a hole formed in the circuit board.

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