KR20090073388A - Backlight unit and liquid crystal display device having the same - Google Patents

Abstract

A backlight unit and a liquid crystal display device using the same are provided to have a structure of replacing a light emitting diode having defect, thereby reducing costs. One or more light emitting diodes(153) are installed in an inner one side of a bottom cover. The light emitting diode is mounted on a PCB(Printed Circuit Board)(152). Connectors(191,192) are installed on the printed circuit board. The connector electrically connects the printed circuit board with the light emitting diode. The connector facilitates attachment and detachment of the light emitting diode.

Description

BACKLIGHT UNIT AND LIQUID CRYSTAL DISPLAY DEVICE HAVING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit, and more particularly, to a backlight unit capable of improving assembling and a liquid crystal display using the same.

With the recent development of semiconductor technology, which is rapidly developing in recent years, the demand for flat panel display devices that are smaller and lighter and has improved performance is exploding.

The liquid crystal display (LCD), which has recently been in the spotlight among the flat panel display devices, has advantages such as miniaturization, light weight, and low power consumption, thereby overcoming the disadvantages of the conventional cathode ray tube (CRT). As an alternative means, it has been gradually attracting attention, and is currently used in almost all information processing equipment that requires a display device.

The liquid crystal display generally injects a liquid crystal material between a color filter substrate on which a common electrode and a color filter are formed, and an array substrate on which a thin film transistor and a pixel electrode are formed. By applying different potentials, an electric field is formed to change the arrangement of liquid crystal molecules, and through this, the light transmittance is controlled to express an image.

Since the liquid crystal display panel including the color filter substrate, the array substrate, and the liquid crystal does not emit light by itself, the liquid crystal display panel includes a backlight unit that provides light under the liquid crystal display panel.

The backlight unit may include a light source, a light source housing that surrounds the light source to prevent light loss, a light guide plate for converting light emitted from the light source into surface light, a reflective sheet disposed on the rear surface of the light guide plate, and an optical sheet disposed on the light guide plate. And the like.

The light source generates relatively little heat, generates white light close to natural light, and has a long life of a cold cathode fluorescent lamp (CCFL). However, in a medium / small liquid crystal display, the cold cathode fluorescent lamp (CCFL) is used. BACKGROUND ART Light emitting diodes (LEDs), which have advantages of thinning and color reproducibility as well as low power consumption, have been used.

At least one light emitting diode (LED) used in a medium / small liquid crystal display device of a mobile product such as a mobile phone is provided, and an emission surface of the light emitting diode (LED) from which light is emitted is faced with one side (incident surface) of the light guide plate. It is. Accordingly, light incident on one side (incident surface) of the light guide plate is spread and irradiated to the liquid crystal display panel positioned above the light guide plate.

The light emitting diode (LED) provided in the small / small liquid crystal display device is a point light source, and is disposed not only to form one surface with the light guide plate in order to maintain uniform brightness, but also to be in close contact with one side (incident surface) of the light guide plate. Is placed.

However, in a general liquid crystal display device, since a plurality of light emitting diodes (LEDs) are packaged on a flexible circuit board, it is difficult to replace them when any one of the light emitting diodes (LEDs) is defective. That is, the general liquid crystal display device has a problem in that the entirety of the light emitting diode should be discarded if any one of the plurality of light emitting diodes occurs.

For example, the components of the backlight unit and the liquid crystal display panel have a structure attached by a light-shielding tape having a strong adhesive force, so that the separation of the backlight unit components is difficult in the event of any failure of the backlight unit.

SUMMARY OF THE INVENTION An object of the present invention is to provide a backlight unit and a liquid crystal display device having the same, which can reduce cost and improve assembly.

The backlight unit according to an embodiment of the present invention,

Bottom cover; At least one light emitting diode provided on one side of the bottom cover; A circuit board on which the light emitting diode is mounted; And a connector provided on the circuit board to electrically connect the circuit board and the light emitting diode and to facilitate the detachment of the light emitting diode.

In addition, the liquid crystal display device of the present invention,

A liquid crystal display panel; A bottom cover disposed on a bottom surface of the liquid crystal display panel; At least one light emitting diode provided on one side of the bottom cover; A circuit board on which the light emitting diode is mounted; And a connector provided on the circuit board to electrically connect the circuit board and the light emitting diode and to facilitate the detachment of the light emitting diode.

The present invention has a structure in which a light emitting diode is easily detached even if any defect occurs among a plurality of light emitting diodes. Therefore, the present invention is a structure that can replace a light emitting diode in which any one of the failures, it is possible to reduce the cost accordingly.

In addition, the present invention has a structure in which only the light source unit can be separately assembled as compared to the conventional liquid crystal display device, thereby improving the assemblability.

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

1 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention, FIG. 2 is an exploded perspective view illustrating the light source unit of FIG. 1, and FIG. 3 is cut along the line II ′ of FIG. 2. It is sectional drawing of one light source unit.

1 to 3, a small liquid crystal display according to an exemplary embodiment of the present invention includes a liquid crystal display panel 110 displaying an image and a backlight unit providing light to the liquid crystal display panel 110. And the first and second light blocking tapes 100a and 100b fixing the backlight unit 120 and the liquid crystal display panel 110. The backlight unit 120 guides the light to supply the light to the liquid crystal display panel 110, and the liquid crystal display panel 110 disposed on the backlight unit 120 controls the supplied light to display an image.

Although not shown in detail in the drawing, the liquid crystal display panel 110 includes a thin film transistor substrate including a plurality of thin film transistors (TFT), a color filter substrate disposed on the thin film transistor substrate, and interposed therebetween. Liquid crystal (not shown). The color filter substrate disposed on the thin film transistor substrate is a substrate in which R, G, and B color filters, in which a predetermined color is expressed while light passes, are formed by a thin film process, and a common electrode made of ITO on the RGB color filter. Is deposited.

In addition, one end of the thin film transistor substrate includes an integrated circuit chip (IC CHIP). The integrated circuit chip generates an image signal and a scan signal for driving the liquid crystal display, and a plurality of timing signals for applying the signals, and transmits the image signal and the scan signal to the gate line and data of the liquid crystal display panel 110. To the line.

The backlight unit 120 disposed on the rear surface of the liquid crystal display panel 110 and providing light includes a box cover bottom cover 180 having an upper surface opened, and a light source unit disposed on one side of the bottom cover 180. 150 and a light guide plate 160 disposed in parallel with the light source unit 150 to convert light emitted from the light source unit 150 into surface light. Optical sheets 130 for diffusing and condensing light are disposed on the light guide plate 160, and light traveling in a lower direction of the light guide plate 160 under the light guide plate 160 toward the liquid crystal display panel 110. Reflecting sheet 170 for reflecting is disposed.

The bottom cover 180 has first and second receiving grooves 181a and 181b for fixing the light source unit 150 to side surfaces corresponding to the light source unit 150.

The light source unit 150 may include a light source case 151 having an open lower surface, a flexible printed circuit board 152 fixed to an inner wall of the light source case 151, and a plurality of mounted on the flexible printed circuit board 152. And a light emitting diode 153.

Both sides of the light source case 151 are seated in the first and second receiving grooves 181a and 181b of the bottom cover 180 to be fixed to the bottom cover 180.

The light source case 151 has a hole-shaped exit portion 156 formed on one side corresponding to the side surface of the light guide plate 160, and the flexible circuit board 152 is externally formed on the other side corresponding to the exit portion 156. A groove-shaped lead-out unit 157 is formed to be electrically connected to the backlight driver (not shown).

The light source case 151 is preferably made of a mold material capable of reflecting light.

The flexible circuit board 152 includes a base film 152a, a wiring pattern 152b formed on the base film 152a, and a protective layer 152c formed on the base film 152a and the wiring pattern 152b. ).

The light emitting diode 153 is fixed on the flexible circuit board 152, and the wiring of the flexible circuit board 152 and the first and second electrodes 154 and 155 of the light emitting diode 153 are electrically connected to each other. First and second connectors 191 and 192 are provided.

The first and second connectors 191 and 192 may include first and second fixing members 193 and 194 for fixing the first and second electrodes 154 and 155, and the first and second fixing members. First and second connection terminals 195 and 196 extending from the inner sidewalls of the first and second side surfaces 193 and 194.

The first and second fixing members 193 and 194 may be made of a plastic material having a certain elasticity, and a round protrusion may be formed on side surfaces facing each other.

The locking projections firmly fix the first and second electrodes 154 and 155 of the light emitting diode 153.

The first and second connection terminals 195 and 196 are electrically connected to the conductive wires 152b of the flexible circuit board 152.

In the light source unit 150 having the above structure, when the light emitting diode 153 is defective, the first and second connectors 191 and 192, which are easily detachable from the light emitting diode 153, are provided on the flexible circuit board 152. Has the advantage of being easy to replace.

A second light blocking tape 100b is attached to an upper surface of the light source unit 150, that is, an upper surface of the light source case 151 to block light leakage generated at an edge of the light source unit 150. In addition, a first light blocking tape 100a is attached to an edge of the lower surface of the liquid crystal display panel 110 to fix the liquid crystal display panel 110, the optical sheets 130, the light guide plate 160, and the reflective sheet 170. At the same time, light leakage from the edge of the liquid crystal display is blocked.

That is, it can be seen that the first and second light blocking tapes 100a and 100b are coated with adhesive materials on both surfaces thereof, and the whole is made of black.

The first and second light blocking tapes 100a and 100b have a structure separated from each other. The first and second light blocking tapes 100a and 100b have a structure in which the first and second light shielding tapes 100a and 100b are separated, so that the light source unit 150 can be easily separated from the liquid crystal display when the light emitting diode 153 is defective. For sake.

The liquid crystal display according to the exemplary embodiment of the present invention described above has a structure in which the light emitting diode 153 can be easily attached or detached even if any defect occurs among the plurality of light emitting diodes 153.

Therefore, the present invention is a structure that can replace the light emitting diode 153 in which any one of the failures, it can reduce the cost accordingly.

In addition, the present invention is a structure that can be assembled separately from the light source unit 150, compared to the conventional liquid crystal display device, it is possible to improve the assembly.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the technical spirit of the present invention. Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification but should be defined by the claims.

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

2 is an exploded perspective view illustrating the light source unit of FIG. 1.

3 is a cross-sectional view of the light source unit cut along the line II ′ of FIG. 2.

Claims (9)

Bottom cover; At least one light emitting diode provided on one side of the bottom cover; A circuit board on which the light emitting diode is mounted; And And a connector provided on the circuit board to electrically connect the circuit board and the light emitting diode and to facilitate the detachment of the light emitting diode. According to claim 1, The connector has a constant elasticity, A fixing member fixing the electrode of the light emitting diode; And And a connection terminal extending from the inside of the fixing member to the bottom surface and electrically connected to the wiring of the circuit board. According to claim 1, And a light source case accommodating the light emitting diode and the circuit board. The method of claim 3, wherein And a receiving groove for fixing the light source case to a side of the bottom cover corresponding to the side of the light source case. A liquid crystal display panel; A bottom cover disposed on a bottom surface of the liquid crystal display panel; At least one light emitting diode provided on one side of the bottom cover; A circuit board on which the light emitting diode is mounted; And And a connector provided on the circuit board to electrically connect the circuit board and the light emitting diode and to facilitate the detachment of the light emitting diode. The method of claim 5, The connector, A fixing member having a constant elasticity and fixing an electrode of the light emitting diode; And And a connection terminal extending from the inside of the fixing member to the bottom surface and electrically connected to the wiring of the circuit board. The method of claim 5, And a light source case accommodating the light emitting diode and the circuit board. The method of claim 7, wherein And a receiving groove for fixing the light source case to a side of the bottom cover corresponding to the side of the light source case. The method of claim 7, wherein And a first light blocking tape on an edge of a lower surface of the liquid crystal display panel, and a second light blocking tape on an upper surface of the light source case.

Images