KR20080054555A - Backlight unit and lc display device - Google Patents

Abstract

A backlight unit and an LCD(Liquid Crystal Display) having the backlight unit are provided to connect an inverter PCB(Printed Circuit Board) and a balance PCB electrically which supply driving voltages to a backlight lamp through a simple method, thereby reducing the manufacturing cost and decrease leakage current. A backlight unit includes a lamp(60) having an electrode(62), a balance PCB(70), a lamp case(50), and an inverter PCB(80). The balance PCB includes a lamp holder(72) for holding the lamp and a first socket(74) having a conductive pin(76) electrically connected to the electrode of the lamp. The lamp holder is mounted on a first face of the balance PCB and the first socket is mounted on a second face of the balance PCB. The lamp case houses the lamp and the balance PCB and has a socket hole(90) formed at the bottom face thereof. The inverter PCB includes a second socket(82) mounted on one side thereof. The second socket penetrates the socket hole and is electrically connected to the conductive pin.

Description

Backlight unit and liquid crystal display device having same {Backlight unit and LC display device}

1 is a block diagram showing the basic configuration of a general liquid crystal display device

2 is a block diagram showing a general liquid crystal panel and a pixel configuration

3 is a structural perspective view for explaining a direct type backlight for a conventional liquid crystal display device;

4 is a cross-sectional view taken along the line III-III of FIG.

5 is a structural cross-sectional view illustrating a backlight unit according to the present invention.

6 is a structural cross-sectional view showing a coupling form of the backlight unit according to the present invention.

<Brief description of the main parts of the drawing>

50: lower case 60: lamp

62: electrode 64: power supply wiring

70: Balance PCB 72: Lamp Holder

74: first socket 76: first conductive pin

78: locking pin 80: inverter PCB

82: second socket 84: second conductive pin

90: socket through hole

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit and a display device thereof, and more particularly, to a backlight unit and a liquid crystal display device having the advantages of simplifying a process, reducing manufacturing cost, and reducing leakage current by changing a connection structure between printed circuit boards.

Among the display devices, in particular, liquid crystal displays have advantages of small size, thinness, and low power consumption, and are used as notebook computers, office automation devices, and audio / video devices. In particular, an active matrix liquid crystal display device using a thin film transistor (hereinafter referred to as "TFT") as a switch element is suitable for displaying a dynamic image.

FIG. 1 is a block diagram illustrating a basic configuration of a general liquid crystal display device, and is largely divided into a liquid crystal panel 2 and an LCM driving circuit unit 26 having a configuration excluding the liquid crystal panel 2.

In each configuration, the interface 10 includes data (RGB Data) and control signals (input clock, horizontal synchronous signal, vertical synchronous signal, data enable signal, etc.) input from the drive system such as a personal computer to the LCM drive circuit. Are supplied to the timing controller 12. Mainly, LVDS (Low Voltage Differential Signal) interface and TTL interface are used for data and control signal transmission from driving system. In addition, the interface function may be collected and used together with the timing controller 12 in a single chip.

As illustrated in FIG. 2, the liquid crystal panel 2 forms a plurality of pixel regions by crossing a plurality of data lines DL1 to DLm and a plurality of gate lines GL1 to GLn on a glass substrate. In the region, a thin film transistor TFT and a liquid crystal LC are configured to display a screen.

The timing controller 12 drives the data driver 18 composed of a plurality of drive integrated circuits and the gate driver 20 composed of a plurality of gate driver integrated circuits using a control signal input through the interface 10. Generate a control signal for In addition, the data input through the interface 10 is transmitted to the data driver 18.

The reference voltage generator 16 generates reference voltages of a digital to analog converter (DAC) used in the data driver 18. Reference voltages are set by the producer based on the transmittance-voltage characteristics of the panel.

The data driver 18 selects reference voltages for analog conversion of input digital data in response to control signals input from the timing controller 12, and outputs analog video data generated by the selected reference voltage to the liquid crystal panel 2. It is supplied to the to control the rotation angle of the liquid crystal molecules.

The gate driver 20 performs on / off control of thin film transistors TFTs arranged on the liquid crystal panel 2 in response to control signals input from the timing controller 12. By sequentially enabling the gate lines GL1 to GLn by one horizontal synchronizing time, analog image signals supplied from the data driver 18 are sequentially driven by sequentially driving the thin film transistors TFT on the liquid crystal panel 2 by one line. Each pixel is applied to the pixels connected to the TFTs.

The power supply voltage generator 14 supplies operating power of each component and generates and supplies a common electrode voltage of the liquid crystal panel 2.

In the liquid crystal display device having the above configuration, a backlight assembly for supplying light from the rear side is positioned. In particular, a large sized panel adopts a direct type backlight assembly in which a plurality of lamps are positioned below the liquid crystal panel.

The direct type backlight assembly does not require a light guide plate for converting the linear light of the lamp into the surface light, and a plurality of lamps provided on the lower side of the display surface and a reflective sheet for reflecting light emitted from the lamp to the display surface to prevent light loss. And light scattering means including a diffuser plate and a plurality of diffuser sheets to scatter light on top of the lamp.

3 is a structural perspective view illustrating a conventional direct type backlight for a liquid crystal display, and FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3.

3, a plurality of lamps 1 having both electrodes fixed to a lamp holder 6 fixed on a balance PCB 8, and a lower portion of the balance PCB 8 and the lamps 1 placed therein. And a case 3 and a plurality of light scattering means 5a, 5b, 5c disposed between the lamps 1 and the liquid crystal panel 2.

The light scattering means (5a, 5b, 5c) is to prevent the shape of the light emitting lamp from appearing on the display surface of the liquid crystal panel and to provide a light source having an overall uniform brightness distribution, in order to enhance the light scattering effect A plurality of diffusion sheets, a diffusion plate, and the like are formed between the cells.

In addition, a reflector (not shown) may be further disposed on the inner bottom surface of the lower case 3 so that light generated from the lamp 1 may be concentrated onto the display of the liquid crystal panel, which is to maximize light utilization efficiency. to be.

The lamp 1 is a Cold Cathode Fluorescent Lamp (CCFL), and electrodes are disposed at both ends of a tube and emit light when power is applied to the electrodes, and both ends of the lamp 1 are respectively It fits in the groove of the lamp holder 6 made of synthetic resin or rubber.

In addition, both ends of the lamp 1 are supplied with power from the balance PCB 8 to which the lamp holder 6 is fixed. The balance PCB 8 is an inverter PCB 9 formed on the rear surface of the lower case 3. ) Is connected to the power supply wire (7) and receives a high voltage lamp driving power.

Here, the balance PCB (8) is a printed circuit board for receiving the lamp driving power from the inverter PCB (9) to deliver to the electrode of the lamp (1) fixed to the lamp holder (6) a capacitor for lighting the lamp A capacitor may be constructed.

4, the balance PCB 8 located on the inner bottom surface of the lower case 3 is located on the rear surface of the lower case 3. ) And a power supply wire (7), wherein the power supply wire (7) penetrates through the wire hole (4) formed at the bottom of the lower case (3) and the balance PCB (8) and the inverter PCB (9) ).

Here, the inverter PCB (9) is a printed circuit board is composed of a circuit portion for power generation and light emission control for driving the lamp (1).

As described above, the backlight unit of the related art uses the power supply wire 7 in connecting the balance PCB 8 and the inverter PCB 9. Therefore, the connection operation of the power supply wire 7 that is not automated is disadvantageous of the manual process and the increase of the process.

In addition, since a high voltage of several hundred volts or more is transmitted through the power supply wire 7, there is a risk of degradation of the EMI characteristic and leakage current.

The present invention has been made to solve the above problems, in a simpler method to provide an electrical connection between the inverter PCB and the balance PCB for supplying driving power to the backlight lamp across the lamp housing in the direct backlight model It is an object of the present invention to provide a backlight unit and its display device which are advantageous for automation and which reduce process water and manufacturing cost and reduce the risk of leakage current.

The present invention to achieve the above object,

A lamp having an electrode; A balance PCB comprising a lamp holder, to which the lamp is coupled, formed on a first surface, and a first socket on which a first conductive pin electrically connected to an electrode of the lamp protrudes; A lamp case in which the lamp and the balance PCB are placed, and a socket through hole is formed at a bottom thereof; A backlight unit for a display device including an inverter PCB positioned on a rear surface of the lamp case and having a second socket having a second conductive pin electrically connected to the first conductive pin through the socket through hole. do.

The lamp holder is characterized in that the synthetic resin or rubber material.

The first conductive pin and the second conductive pin are characterized in that each of the bar (bar) shape.

The first and second surfaces of the balance PCB may be surfaces facing each other.

The first socket and the second socket is characterized in that the socket of the structure that is mechanically fitted to each other.

The first socket is convex, and the second socket is concave.

The first socket may further include a locking pin that penetrates through the socket through hole and is attached to the rear surface of the lamp case.

The locking pin is characterized in that the hook shape.

The lamp is characterized in that the fluorescent lamp.

It further comprises a reflective sheet configured on the inner surface of the lamp case.

In addition, the present invention, the liquid crystal panel; A liquid crystal display device including the backlight unit having the above-described configuration and features is provided.

The liquid crystal display further includes a plurality of optical sheets positioned between the liquid crystal panel and the backlight unit.

The plurality of optical sheets is characterized in that it comprises a diffusion sheet.

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

5 is a structural cross-sectional view illustrating a backlight unit according to the present invention, and is applied to a liquid crystal display device having a direct backlight structure.

In the configuration, a lamp 60 is positioned in the lower case 50, and a balance PCB 70 including a lamp holder 72 and a first socket 74 is disposed, and a rear surface of the lower case 50 is formed. Inverter PCB 80 configured with two sockets 82 is configured.

The lower case 50 serves to protect the lamp 60 in a direct backlight type, and a socket through-hole 90 is formed at a bottom surface thereof.

The lamp 60 is a fluorescent lamp (CCFL), the inner bottom surface of the lower case 50 may further comprise a reflective sheet for improving the light use efficiency by reflecting the light of the lamp 60 upwards. have.

The balance PCB 70 is a printed circuit board for receiving a lamp driving power from the inverter PCB 80 and delivering the lamp driving power to the electrode 62 of the lamp 60 coupled to the lamp holder 72. The lamp holder 72 is configured and the first socket 74 is formed on the lower surface thereof. In this case, the balance PCB 70 may include a capacitor necessary for controlling the lighting of the lamp 60.

The lamp holder 72 is made of a synthetic resin or rubber material, and both ends of the lamp 60 including the electrode 62 are respectively supported to support the lamp 60 and to supply power to the lamp driving power. 64 is used as a formation route.

The first socket 74 is made of plastic or synthetic resin and is formed on the bottom surface of the balance PCB 70 so as to penetrate the socket through hole 90 of the bottom surface of the lower case 50. 74 is configured to protrude downward from the first conductive pin 76 of a bar type which is electrically / circuitly connected to the power line 64 extending from the lamp electrode 62.

In addition, the first socket 74 is further provided with a locking pin (78) to pass through the socket through hole 90 to perform a mechanical coupling with the lower case (50). The locking pin 78 has a hook shape or a locking jaw at its end and is fixed to the rear surface of the lower case 50 so that the first socket 74 is not moved to the inner surface of the lower case 50. do. Of course, the locking pin 78 is manufactured integrally with the first socket 74.

The inverter PCB 80 generates and outputs a lamp driving power for emitting light of the lamp 60 by using a supply power applied from a power supply device or a power supply circuit unit. For this purpose, the inverter circuit for controlling the lamp 60 is provided. In some embodiments, a second socket 82 is formed on the top surface of which a mechanical / electrical coupling with the first socket 74 is performed.

Like the first socket 74, the second socket 82 is made of plastic or synthetic resin, and when coupled with the first socket 74, the first conductive pin 76 of the first socket 74 The second conductive pin 84 of the bar type in contact with the () is configured. In this case, the second conductive pin 84 is configured in the first socket 82, and the first conductive pin 76 is inserted into the second socket 82 to allow the second conductive pin 84 to be inserted into the second socket 82. ).

Therefore, the first socket 74 and the second socket 82 are most preferably each of the mechanical shape has a concave-convex relationship, such as convex shape and concave shape, and can be fitted mechanically If the structure is applicable to other forms.

The coupling form and effects of the backlight unit according to the present invention will be described with reference to FIG. 6.

6, the first socket 74 of the balance PCB 70 and the second socket 82 of the inverter PCB 80 are formed through the socket through hole of the lower case 50 (see 90 of FIG. 5). This combined cross section is shown.

Accordingly, the first conductive pin 76 of the first socket 74 and the second conductive pin 84 of the second socket 82 are in contact with each other, so that the lamp is moved from the inverter PCB 80 to the balance PCB 70 side. Transfer of drive power is performed. Therefore, since a separate power supply wire (wiring wire) is unnecessary for electrical connection between the inverter PCB 80 and the balance PCB 70, it is possible to expect an effect of simplifying assembly and reducing manufacturing costs.

In addition, the locking pins 78 of the first socket 74 are coupled to the rear surface of the lower case 50 to fix the balance PCB 70. Therefore, the lamp 60 also provides the effect of being fixed so as not to move in the lower case 50, and maintain the shortest distance for the lamp driving power output from the inverter PCB 80 is transmitted to the lamp 60. This provides the advantage of reducing leakage current.

In the backlight unit according to the present invention described above, the liquid crystal panel is positioned on the upper side, and a plurality of optical sheets such as a diffusion sheet are used between the liquid crystal panel and the backlight unit according to the present invention, so that a separate power supply is provided. The absence of a wire provides the advantage of minimizing EMI to the liquid crystal panel side.

The backlight unit according to the present invention described above has been improved from the wire connection structure to the socket coupling structure in supplying lamp driving power from the outside to the inside of the lower case. This simplifies the manufacturing process, reduces manufacturing costs due to wire removal, reduces leakage current due to shortened wiring paths, and reduces EMI on the liquid crystal panel side.

Claims (13)

A lamp having an electrode; A balance PCB comprising a lamp holder, to which the lamp is coupled, formed on a first surface, and a first socket on which a first conductive pin electrically connected to an electrode of the lamp protrudes; A lamp case in which the lamp and the balance PCB are placed, and a socket through hole is formed at a bottom thereof; An inverter PCB positioned on a rear surface of the lamp case and having a second socket having a second conductive pin electrically connected to the first conductive pin through the socket through hole; Backlight unit for display device including a The method according to claim 1, The lamp holder is a backlight unit for a display device, characterized in that the synthetic resin or rubber material The method according to claim 1, The first conductive pin and the second conductive pin each have a bar shape. The method according to claim 1, The first and second surfaces of the balance PCB are surfaces facing each other. The method according to claim 1, The first socket and the second socket is a backlight unit of the display device, characterized in that the socket is mechanically fitted to each other structure The method according to claim 1, Wherein the first socket is convex and the second socket is concave. The method according to claim 1, The first socket may further include a locking pin penetrating the socket through hole to be attached to the rear surface of the lamp case. The method of claim 7, wherein The locking pin is a hook unit for a display device, characterized in that the hook shape. The method according to claim 1, The lamp unit is a backlight unit for a display device, characterized in that the fluorescent lamp The method according to claim 1, Back light unit for display device further comprising a reflective sheet formed on the inner bottom surface of the lamp case A liquid crystal panel; The first socket having a lamp positioned below the liquid crystal panel and having an electrode, and a lamp holder to which the lamp is coupled is formed on the first surface, and the first conductive pin which is electrically connected to the electrode of the lamp is protruded. A balance PCB configured to be configured, a lamp case having a socket through-hole formed on the bottom of the lamp and the balance PCB, and a second conductive part disposed on the back of the lamp case and electrically connected to the first conductive pin through the socket through hole. Backlight unit comprising an inverter PCB configured on one side of the second socket having a pin Liquid crystal display comprising a The method of claim 11, A liquid crystal display further comprising a plurality of optical sheets positioned between the liquid crystal panel and the backlight unit. The method according to claim 12, The plurality of optical sheets is a liquid crystal display device comprising a diffusion sheet

Images