KR20060001400A - Backlight unit - Google Patents

Abstract

The present invention can be used in a large-area display device, and to provide a backlight unit having a surface emitting lamp capable of split driving, the backlight unit for achieving the above object is a surface emitting light tiled with a plurality of surface emitting lamps A lamp unit; First and second power lines connected to apply power to each of the surface emitting lamps; A plurality of inverters for applying driving signals to first and second power lines of each of the surface emitting lamps; It characterized in that it comprises a light scattering means provided between the surface light emitting lamp unit and the liquid crystal panel.

Surface Emitting Lamp, Power Line, Backlight

Description

Backlight Unit {BACKLIGHT UNIT}

1 is a perspective view showing a backlight unit according to the prior art

2 is a perspective view showing a backlight unit according to another conventional technology

3 is a perspective view of a backlight unit according to the present invention;

4 to 9 are various plan views of the surface light emitting lamp of the backlight unit according to the first to sixth embodiments of the present invention;

10 and 11 are perspective views of the structure of the unit surface light source lamp for applying the present invention

Explanation of symbols on the main parts of the drawings

30: surface emitting lamp portion 31a, 31b: inverter

32: power supply line 32a, 32b: 1st, 2nd power supply line

33a: diffusion plate 33b: diffusion sheet

33: light scattering means 34: liquid crystal panel

35: source printed circuit board 36: gate printed circuit board

40, 50, 60, 70, 80, 90: first surface emitting lamp

41, 51, 61, 71, 81, 91: second surface emitting lamp

52, 62, 72, 82, 92: third surface emitting lamp

53, 63, 73: Fourth surface emitting lamp 74: The fifth surface emitting lamp                 

75: sixth surface emitting lamp 100, 110: upper substrate

101, 111: lower substrates 102a, 102b: first and second electrode

112a and 112b: first and second external electrodes

The present invention relates to a backlight unit, and more particularly, to a backlight unit having a surface emitting lamp capable of divided driving.

CRT (Cathode Ray Tube), one of the commonly used display devices, is mainly used for monitors such as TVs, measuring devices, and information terminal devices.However, due to the weight and size of the CRT itself, Could not respond actively to demands.

Therefore, in the trend of miniaturization and weight reduction of various electronic products, CRT has a certain limit in weight and size, and is expected to replace the liquid crystal display device (LCD) using the electro-optic effect, and gas discharge. There are plasma display panels (PDPs) and electroluminescent displays (ELDs) using electroluminescent effects, among which researches on liquid crystal displays (LCDs) are being actively conducted.

In order to replace the CRT, liquid crystal display devices having advantages such as small size, light weight, and low power consumption have been actively developed, and recently, an ultra-thin flat display having a thickness of only a few centimeters (Cm) is present. Developed enough to fulfill its role as a display device, it is used in spacecraft, aircraft, laptop computers, laptop computer monitors, desktop computer monitors, and large information display devices, and the demand for liquid crystal display devices is continuously increasing. It is true.

Since most of the liquid crystal display devices are light-receiving devices that display images by controlling the amount of light coming from the outside, a separate light source, that is, a backlight unit, for irradiating light to the LCD panel is necessary.

In general, a backlight unit used as a light source of a liquid crystal display device is classified into an edge method and a direct method according to a method of arranging a cylindrical light emitting lamp.

First, the edge method is that the lamp unit is installed on the side of the light guide plate for guiding the light, the lamp unit is a lamp that emits light, the lamp holder which is inserted at both ends of the lamp to protect the lamp and the outer peripheral surface of the lamp and one side It is provided with a lamp reflection plate fitted to the side of the light guide plate to reflect the light emitted from the lamp toward the light guide plate.

The edge method in which the lamp unit is installed on the side of the light guide plate is applied to a relatively small liquid crystal display device such as a monitor of a laptop computer and a desktop computer, and has good light uniformity and a long durability life. It is advantageous to thin the liquid crystal display device.

On the other hand, the direct method began to be developed mainly as the size of the liquid crystal display device became larger than 20 inches, and arranged a plurality of lamps in a row on the lower surface of the diffuser plate to direct light directly to the front of the LCD panel. will be.

The direct method is mainly used for a large screen liquid crystal display device requiring high luminance because the light utilization efficiency is higher than that of the edge method.

However, the liquid crystal display device adopting the direct method is used as a large monitor or a television, so it takes longer to use than a laptop computer and the number of lamps is larger, so that the liquid crystal of the direct method is lower than the edge type liquid crystal display device. It is more likely that a lamp that will not turn on will appear due to the failure and life of the lamp in the display.

In addition, in the edge method in which the lamp units are installed on both side surfaces of the light guide plate, due to the life and failure of the lamp, for example, when only one lamp is not turned on, only the brightness on the screen is lowered. However, in the direct method, since a plurality of lamps are installed at the bottom of the screen, for example, due to the life and failure of the lamp, if one lamp does not light up, the part where the lamp is not lit becomes significantly darker than the other part. The part that does not appear immediately on the screen.

For this reason, since the lamp is frequently replaced in the direct type liquid crystal display device, the direct type liquid crystal display device should have an easy structure for disassembling and assembling the lamp unit.

Hereinafter, a backlight unit according to the related art will be described with reference to the accompanying drawings.

1 is a diagram illustrating a structure of a direct type backlight unit according to the related art, and FIG. 2 is a diagram illustrating a structure of a surface emitting lamp according to another conventional technique.                         

As shown in FIG. 1, the backlight unit according to the related art includes a plurality of light emitting lamps 1, an outer case 3 for fixing and supporting the light emitting lamps 1, and the light emitting lamps 1. And light scattering means 5a, 5b, 5c disposed between the liquid crystal panel (not shown).

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, diffusion plates, and the like are disposed between the cells.

The inner surface of the outer case 3 is disposed with a reflector 7 so that the light emitted from the light emitting lamp 1 can be concentrated to the display unit of the liquid crystal panel, which is to maximize the utilization efficiency of the light.

The light emitting lamp 1 is a Cold Cathode Fluorescent Lamp (CCFL), and electrodes are disposed at both ends of a tube to emit light when power is applied to the electrodes, and both ends of the light emitting lamp 1 are discharged. Is fitted into grooves formed on both sides of the outer case 3.

Power lead wires 9 and 9a for transmitting power for driving the lamp are connected to both electrodes of the light emitting lamp, and the power lead wires 9 and 9a are connected to a separate connector and connected to the driving circuit. Therefore, a separate connector is required for each light emitting lamp 1.

That is, a power lead wire 9 connected to one electrode of the light emitting lamp and a power lead wire 9a connected to the other electrode are connected to one connector, and one of the power lead wires 9 and 9a is connected to the outer case 3. Bends down to connect with the connector.

As described above, the backlight unit used as a light source using a plurality of tube-type lamps is expensive to manufacture because there are many kinds of required parts, and when one lamp is not lit, the part where the lamp is not lit is significantly darker than the other parts. Since the portion where the lamp is not turned on immediately appears on the screen, there is a problem that the uniformity of the lamp brightness is lowered.

In order to solve this problem, a surface emitting lamp which can be used as a backlight itself has been proposed.

As shown in FIG. 2, the surface light emitting lamp according to the related art maintains a constant gap between the upper and lower substrates 20 and 21 and the upper and lower substrates 20 and 21 bonded to each other with a predetermined gap. It is composed of a support 22 configured in one region so that the anode and cathode electrodes 23, 24 alternately disposed on the lower substrate 21. Mixed gas of Ne, Hg, and Xe enters between the upper and lower substrates 20 and 21 bonded to each other.

Such surface emitting structure can save the unit cost and can emit light to the top to improve the brightness uniformity of the lamp. However, it is possible to realize dynamic and high contrast ratio partial luminance and division driving. There is a limit to this.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is an object of the present invention to provide a backlight unit having a surface light emitting lamp which can be used in a large area display device and which can be dividedly driven.

According to an aspect of the present invention, there is provided a backlight unit including: a surface emitting lamp unit in which a plurality of surface emitting lamps are tiled; First and second power lines connected to apply power to each of the surface emitting lamps; A plurality of inverters for applying driving signals to first and second power lines of each of the surface emitting lamps; It characterized in that it comprises a light scattering means provided between the surface light emitting lamp unit and the liquid crystal panel.

The light scattering means is characterized by consisting of a diffusion plate and a plurality of diffusion sheets.

The surface emitting lamp unit may be configured of two surface emitting lamps tiled side by side.

The surface emitting lamp unit may further include configuring four surface emitting lamps by tiling them side by side.

The surface emitting lamp unit may further include arranging two surface emitting lamps in a horizontal direction and tiling the two surface emitting lamps in parallel therebetween.

The surface emitting lamp unit may further include configuring the six surface emitting lamps by tiling them side by side in two rows of three in the horizontal direction.

The surface light emitting lamp unit may further include two surface light emitting lamps tiled up and down side by side on one surface light emitting lamp.

The surface emitting lamp unit may further include configuring three surface emitting lamps by tiling them side by side, top, middle, and bottom.

The surface light source lamp may include an upper substrate, a lower substrate joined to the upper substrate, and having a plurality of zig-zag inner grooves formed therein, a phosphor coated on an inner surface of the upper substrate, and a space between the upper and lower substrates. And a first electrode and a second electrode rod inserted into both ends of the injected discharge gas and the inner groove of the lower substrate to protrude outward.

The surface light source lamp has a curved upper substrate having a plurality of convex portions protruding downward to serve as a support, and a lower substrate having opposing opposite sides to the upper substrate and having first and second external electrodes at both outer edges thereof. And a discharge gas injected into a space between the upper and lower substrates, and a phosphor coated on an inner surface of the upper substrate.

Referring to the accompanying drawings, a backlight unit according to a preferred embodiment of the present invention will be described.

3 is a perspective view of a backlight unit according to the present invention, and FIGS. 4 to 9 are various plan views of the surface emitting lamp unit of the backlight unit according to the first to sixth embodiments of the present invention.

 The backlight unit according to the present invention is characterized by tiling a plurality of surface emitting lamps and connecting power lines separately so as to separately drive the plurality of surface emitting lamps.

As shown in FIG. 3, a surface emitting lamp unit 30 in which a plurality of surface emitting lamps are tiled, a plurality of inverters 31a and 31b provided to apply power to each of the surface emitting lamps, It consists of a light scattering means 33 composed of a diffusion plate 33a and a plurality of diffusion sheets 33b between the surface light emitting lamp unit 30 and the liquid crystal panel 34.

Reference numerals 35 and 36 denote source and printed circuit boards 35 and 36 for applying driving signals to the data lines and the gate lines of the liquid crystal panel, respectively.

The light scattering means 33 is provided to prevent the shape of the tiled surface light emitting lamp from appearing on the display surface of the liquid crystal panel 34 and to enhance the light scattering effect of light output through the surface light emitting lamp unit 33. It is.

In the above-described surface emitting lamps, power lines 32 are provided with angles, and the power lines 32 are composed of first and second power lines 32a and 32b, and the first and second power lines 32a, 32b is connected to adjacent inverters 31a and 31b, respectively.

As described above, a plurality of surface emitting lamps are tiled to configure a direct type backlight unit, and each of the surface emitting lamps can be divided and driven independently because the first and second power lines 32a and 32b are connected to adjacent inverters. .

In addition, a plurality of small sized surface emitting lamps may be tiled and applied to a large area display device.

In the above, a plurality of tiled surface emitting lamps may be configured, and in this case, the size of each surface emitting lamp of the surface emitting lamp unit may vary, and may be used by tiling into various shapes.                     

Hereinafter, various forms of the surface light emitting lamp unit 30 will be described by dividing according to embodiments.

As shown in FIG. 4, the first embodiment is formed by tiling two first and second surface emitting lamps 40 and 41 side by side, and each of the first and second surface emitting lamps 40 and 41 has a shape. The first and second power supply lines 32a and 32b for driving are respectively connected. In FIG. 4, the first and second surface emitting lamps 40 and 41 are shown to be the same both horizontally and vertically, but the horizontal lengths may be configured differently.

As shown in FIG. 5, the second embodiment is configured by tiling four first to fourth surface emitting lamps 50, 51, 52, and 53 side by side, and each of the first to fourth surface emitting lamps. The first and second power lines 32a and 32b for driving are connected to the lamps 50, 51, 52, and 53, respectively. Although four surface light emitting lamps having a square shape are shown in FIG. 5, a rectangular surface light emitting lamp that is not square may be tiled.

As shown in FIG. 6, the third embodiment is formed by tiling four first to fourth surface light emitting lamps 60, 61, 62, and 63, and the first and second surface light emitting lamps extend in the horizontal direction. (60, 61) were arrange | positioned and the 3rd and 4th surface emitting lamps 62 and 63 were tiled side by side, and it comprised. In this case, the first and second power supply lines 32a and 32b for driving are connected to the first to fourth surface emitting lamps 60, 61, 62, and 63, respectively. In FIG. 6, each surface emitting lamp is configured as a rectangle, but may be configured as a mixture of a rectangle and a square.

As shown in FIG. 7, the sixth embodiment is configured by tiling six first to sixth surface emitting lamps 70, 71, 72, 73, 74, and 75 side by side in two rows of three tiles. In this case, the first and second power supply lines 32a and 32b for driving are connected to the first to sixth surface emitting lamps 70, 71, 72, 73, 74, and 75, respectively. In FIG. 7, each surface emitting lamp is configured as a square, but may be configured as a mixture of a rectangle and a square.

As shown in FIG. 8, the fifth embodiment is formed by tiling three first to third surface emitting lamps 80, 81, and 82, and at this time, the second surface is disposed on one side of the first surface emitting lamp 80. And the third surface emitting lamps 81 and 82 were tiled up and down. In this case, the first and second power source lines 32a and 32b for driving are connected to the first to third surface emitting lamps 80, 81, and 82, respectively. In FIG. 8, each surface emitting lamp is configured as a square, but may be configured as a mixture of a rectangle and a square.

As shown in FIG. 9, the sixth embodiment is configured by tiling three first to third surface emitting lamps 90, 91, and 92 side by side up and down, and at this time, the first to third surfaces. The first and second power lines 32a and 32b for driving are connected to the light emitting lamps 90, 91, and 92, respectively. Although each surface emitting lamp is comprised by the rectangle long in a horizontal direction in FIG. 9, it can also be comprised by square.

As described above, one surface light emitting lamp unit may be formed by tiling surface light emitting lamps having various sizes and arrangements, and each of the surface light emitting lamps is provided with first and second power lines, respectively, so that separate driving is possible. The brightness can be adjusted independently.                     

Each of the surface emitting lamps may be configured by applying a generally used surface emitting lamp, which will be described below by way of example.

10 and 11 are perspective views showing the structure of a unit surface light source lamp for applying the present invention.

The surface light emitting lamp may be described by dividing it into an internal electrode and an external electrode according to a power application method.

First, as an example of the surface light source lamp for the internal electrode, as shown in FIG. 10, the upper substrate 100 and the lower substrate 101 which are joined to the upper substrate 100 and joined together and have a plurality of zig-zag inner grooves are formed. ), A phosphor (not shown) coated on an inner surface of the upper substrate 100, first and second electrode rods 102a and 102b inserted into both inner grooves of the lower substrate 101 and protruding to the outside; It is composed of a mixed gas of Ne, Hg, Xe injected into the space between the upper and lower substrates (100, 101).

As described above, the surface light source for the internal electrode is provided with first and second electrode rods 102a and 102b inside the lamp, as in a conventional cold cathode lamp (CCFL).

Next, as an example of the surface light source lamp for the external electrode, as shown in FIG. 11, the upper substrate 110 formed with the bend and the upper substrate 110 are joined to face the upper substrate and are joined to the outer edges of the first and second external electrodes. Lower substrate 111 provided with 112a and 112b, discharge gas injected into a space between the upper and lower substrates 110 and 111, and a phosphor coated on an inner surface of the upper substrate 100 (not shown). It is composed of

In this case, the upper substrate 110 has a plurality of convex portions protruding downward to serve as a support when the lower substrate 111 is bonded to the lower substrate 111. A plurality of discharge spaces are defined by the plurality of convex portions.

As described above, in the surface light source for the external electrode, the first and second external electrodes 112a and 112b for applying the electrode are provided on the outside of the lamp like the conventional external electrode light emitting lamp EEFL.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the above embodiments, but should be defined by the claims.

The backlight unit according to the present invention as described above has the following effects.

First, a plurality of surface emitting lamps may be tiled to configure a lamp unit of the backlight unit, and thus may be applied to a large display device.

Second, when tiling a plurality of surface light emitting lamps to form one surface light emitting lamp unit, split driving is possible by providing first and second power lines for applying an electrode to each surface light emitting lamp, respectively.

Claims (10)

A surface light emitting lamp unit in which a plurality of surface light emitting lamps are tiled; First and second power lines connected to apply power to each of the surface emitting lamps; A plurality of inverters for applying driving signals to first and second power lines of each of the surface emitting lamps; And a light scattering means provided between the surface light emitting lamp unit and the liquid crystal panel. The method of claim 1, The light scattering unit is a backlight unit, characterized in that consisting of a diffusion plate and a plurality of diffusion sheets. The method of claim 1, And the surface emitting lamp unit comprises two surface emitting lamps tiled side by side. The method of claim 1, The surface emitting lamp unit further comprises a tile by forming four surface emitting lamps side by side two by two. The method of claim 1, The surface emitting lamp unit further comprises two surface emitting lamps arranged in the horizontal direction and tiling the two surface emitting lamps side by side. The method of claim 1, And the surface emitting lamp unit is configured to tile the six surface emitting lamps side by side in two rows of three in the horizontal direction. The method of claim 1, The surface emitting lamp unit further comprises a tile by forming two surface emitting lamps on one side of one surface emitting lamp side by side, up and down. The method of claim 1, The surface emitting lamp unit further comprises a tile by forming three surface emitting lamps side by side, up and down. The method of claim 1, The surface light source lamp and the upper substrate, A lower substrate opposite to the upper substrate and bonded to each other and having a plurality of zig-zag inner grooves; A phosphor coated on an inner surface of the upper substrate, Discharge gas injected into the space between the upper and lower substrates; And a first electrode and a second electrode rod inserted into both ends of the inner groove of the lower substrate and protruding to the outside. The method of claim 1, The surface light source lamp has an upper substrate having a plurality of convex portions projecting downward to be curved and serve as a support; A lower substrate opposite to the upper substrate and bonded to each other and having first and second external electrodes disposed at both outer edges thereof; Discharge gas injected into the space between the upper and lower substrates; The backlight unit, characterized in that further comprising a phosphor coated on the inner surface of the upper substrate.

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