CN100390640C - Backlight module with light emitting diode - Google Patents

Abstract

A backlight module with light emitting diodes comprises a driving circuit board, a first circuit, a second circuit and a reflecting plate. The driving circuit board comprises a first block and a second block. The first circuit comprises a plurality of first light sources and a plurality of second light sources, the first light sources are arranged in the first block, and the first light sources are arranged in the second block. And the second circuit comprises a plurality of third light sources and a plurality of fourth light sources. The first light source is arranged in the first block, and the fourth light source is arranged in the second block. The reflecting plate is arranged on the driving circuit board and has a convex structure. The first light source, the second light source, the third light source and the fourth light source are arranged on the convex structure.

Description

Backlight module with light emitting diodes

This case is a divisional application whose application date is June 4, 2003 and the application number is 03141253.X, and the title of the invention is "Backlight Module with Light Emitting Diode".

technical field

The invention relates to a backlight module with light-emitting diodes, in particular to a backlight module applied to medium and large size flat panel displays.

Background technique

With the progress of the flat panel display technology, the current flat panel displays have gradually become the mainstream of medium and large size flat panel displays. However, there are still many technical problems to be overcome in the process of progressing from small-sized panels to large-sized panels.

Since the quality of each white light emitting diode is uneven, the internal impedance is often different. Therefore, when such light emitting diodes are arranged in the backlight module of a medium-sized or large-sized flat-panel display, the problem of uneven brightness of the display will occur. As shown in FIG. 1 , the traditional arrangement of light emitting diodes is to provide the brightness required by the area A and the area B of the flat panel display by the circuit 110 provided with the light emitting diodes 111 and 112 and the circuit 120 provided with the light emitting diodes 121 and 122 respectively. Since the circuit 110 and the circuit 120 are arranged in parallel, when the sum of the impedances of the LEDs 111, 112 is greater than the sum of the impedances of the LEDs 121, 122, the current flowing through the circuit 110 will be smaller, so the LEDs 111, 112 The brightness will be less, causing area A of the flat panel display to be darker than area B. When the size of the flat-panel display is small, the situation of uneven brightness is not serious, but when the size gradually increases and the number of light-emitting diodes installed on a single circuit increases, the difference in the sum of impedance will be greater, thus making the brightness uneven effect is more obvious. In addition, general flat-panel displays only provide enough brightness in the direction facing the display. If the viewing angle of the user slightly deviates from the front viewing angle, the brightness of the image received by the eyes will be reduced. This shortcoming exists in medium and large-sized flat-panel displays, and its degree will be more serious.

Therefore, a backlight module with light-emitting diodes that can provide uniform brightness and wide viewing angle is designed to solve the above technical problems.

Contents of the invention

The present invention provides a backlight module with light emitting diodes in order to solve the problems of the above-mentioned known technologies. It includes a driving circuit board, a first circuit, a second circuit and a reflection plate. The driving circuit board includes a first block and a second block. The first circuit includes a plurality of first light sources and a plurality of second light sources, the first light sources are arranged in the first block, and the first light sources are arranged in the second block. A second circuit, the second circuit includes multiple third light sources and multiple fourth light sources. The first light source is set in the first block, and the fourth light source is set in the second block. The reflector is arranged on the driving circuit board, and the reflector has a convex structure. The first light source, the second light source, the third light source and the fourth light source are arranged on the convex structure.

Applying the backlight module with light-emitting diodes of the present invention can provide a light source with uniform brightness and wide viewing angle for a liquid crystal display. Users can watch images with uniform brightness and high resolution from different directions and angles.

Description of drawings

FIG. 1 is a schematic diagram showing a conceptual circuit diagram of a known arrangement of light emitting diodes;

Fig. 2 is a conceptual circuit diagram showing the light source arrangement of the backlight module with light-emitting diodes of the present invention;

Fig. 3 is a schematic structural view showing a backlight module with light-emitting diodes of the present invention;

Figure 4a is a top view showing the convex structure of the backlight module with light emitting diodes of the present invention;

Figure 4b is a side view showing the convex structure of the backlight module with light emitting diodes of the present invention;

FIG. 5 is a schematic diagram showing the light source arrangement circuit of the backlight module with light emitting diodes of the present invention.

Symbol Description:

110, 120: circuit 111, 112, 121, 122: light emitting diode

210: The first circuit 211: The first light source

212: Second light source 220: Second circuit

223: The third light source 224: The fourth light source

230: Drive circuit board 240: Reflector

250: Convex structure 251: First side surface

252: Second side surface 253: Third side surface

254 fourth side surface 255: upper surface

260: light guide plate 261: light incident side

262: groove 270: light source

310, 320, ..., 350: circuits

311, 312, ..., 315: light source

321, 322, ..., 325: light source

331, 332, ..., 335: light source

341, 342, ..., 345: Passive

351, 352, ..., 355: light source

361, 362, ..., 365: convex structure

Detailed ways

Referring to Fig. 2, it is the circuit design concept of the light source of the present invention, it is the first circuit 210 that will be provided with the first light source 211, the second light source 212 and the second circuit 220 that is provided with the 3rd light source 223, the 4th light source 224 It is arranged on a driving circuit board 230 to jointly provide the light source required by the flat panel display. The driving circuit board 230 includes a first block A and a second block B′. The first light source 211 and the third light source 223 are arranged in the first area A' to provide the light source required by the flat panel display in the corresponding area. The fourth light source 224 and the second light source 212 are arranged in the second block B' to provide the light source required by the flat panel display in the corresponding area. Therefore, although the first circuit 210 and the second circuit 220 have different internal impedances, the first light source 211 and the second light source 212 are brighter than the third light source 223 and the fourth light source 224, or the third light source 223 and the second light source are brighter than the third light source 223 and the fourth light source. In the case that the four light sources 224 are brighter than the first light source 211 and the second light source 212, the design concept of this circuit configuration can be used to balance the light sources of the flat-panel display to achieve a flat-panel display backlight module with a uniform light source effect.

The above-mentioned light sources can be light-emitting diodes of any color.

The first circuit 210 and the second circuit 220 mentioned above can be connected to a power supply device (not shown) in parallel.

The aforementioned backlight module with LEDs can be a direct-lit backlight module or a side-lit backlight module.

Referring to FIG. 3 , in the backlight module with light emitting diodes of the present invention, a reflection plate 240 and a light guide plate 260 can be additionally provided on the above-mentioned driving circuit board 230 . A protruding structure 250 may be disposed on the reflecting plate 240 , and the light source 270 is disposed on the protruding structure 250 . The light guide plate 260 has a light incident side 261 and a groove 262 formed at a position corresponding to the light source.

The above-mentioned light source 270 refers to the general term of the light source of the backlight module with light-emitting diodes of the present invention, which represents a collection of light sources arranged in different circuits.

4a and 4b are enlarged views showing the convex structure 250 of the present invention. Here, the protruding structure 250 is a wedge-shaped structure, which includes an upper surface 255 , a first side surface 251 , a second side surface 252 , a third side surface 253 and a fourth side surface 254 . The light source 270 is disposed on the upper surface 255 , the first side surface 251 , the second side surface 252 , the third side surface 253 and the fourth side surface 254 . To provide a multi-angle light source.

The above-mentioned wedge-shaped structure may also include more than four sides to provide light sources with more angles.

The light source 270 is configured using the circuit configuration concept described in FIG. 2 above, and it can be a convex structure as a unit or a region as a unit. Referring to FIG. 5 , there are shown convex structures 361 , 362 , 363 , 364 , 365 , and circuits 310 , 320 , 330 , 340 , 350 . The circuit 310 is provided with light sources 311, 312, 313, 314, 315, the light source 311 is set on the convex structure 361, the light source 312 is set on the convex structure 362, the light source 313 is set on the convex structure 363, and the light source 314 is set on the convex structure 364 , the light source 315 is disposed on the convex structure 365 . Similarly, the circuit 320 is provided with light sources 321, 322, 323, 324, 325, the light source 321 is set on the convex structure 361, the light source 322 is set on the convex structure 362, the light source 323 is set on the convex structure 363, the light source 324 is set on the The convex structure 364 and the light source 325 are disposed on the convex structure 365 . The circuit 330 is provided with light sources 331, 332, 333, 334, 335, the light source 331 is set on the convex structure 361, the light source 332 is set on the convex structure 362, the light source 333 is set on the convex structure 363, and the light source 334 is set on the convex structure 364 , the light source 335 is disposed on the convex structure 365 . The circuit 340 is provided with light sources 341, 342, 343, 344, 345, the light source 341 is set on the convex structure 361, the light source 342 is set on the convex structure 362, the light source 343 is set on the convex structure 363, and the light source 344 is set on the convex structure 364 , the light source 345 is disposed on the convex structure 365 . The circuit 350 is provided with light sources 351, 352, 353, 354, 355, the light source 351 is set on the convex structure 361, the light source 352 is set on the convex structure 362, the light source 353 is set on the convex structure 363, and the light source 354 is set on the convex structure 364 , the light source 355 is disposed on the convex structure 365 .

The above-mentioned light sources 311-315, 321-325, 331-335, 341-345, 351-355 do not need to be arranged on the corresponding surfaces of the convex structures 361-365, for example, the light source 311 can be arranged on the upper surface of the convex structures. 312 can be disposed on the side surface of the convex structure to achieve the goal of uniform brightness.

With the design of the current averaging circuit configuration concept of the present invention, it is also possible to divide the surface of the flat-panel display into several regions instead of using convex structures as configuration units, so as to achieve the effect of uniform light.

The invention can provide uniform and wide-angle light source for liquid crystal display. Users can enjoy uniform brightness and high resolution images from various angles.

Although the present invention has been disclosed above in the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make changes and modifications without departing from the spirit and scope of the present invention. Therefore, the present invention The scope of protection is as defined by the appended claims.

Claims (8)

1. A backlight module with light emitting diodes, comprising: a reflective plate having a convex structure; and At least one light emitting diode is arranged on the convex structure. 2. The backlight module with LEDs as claimed in claim 1, wherein the convex structure is a wedge-shaped structure. 3. The backlight module with light emitting diodes as claimed in claim 2, wherein the wedge-shaped structure comprises an upper surface, a first side surface, a second side surface, a third side surface and a fourth side surface . 4. The backlight module with light emitting diodes as claimed in claim 3, wherein the light emitting diodes are disposed on the upper surface. 5. The backlight module with LEDs as claimed in claim 3, wherein the LEDs are disposed on the first side surface. 6. The backlight module with LEDs as claimed in claim 3, wherein the LEDs are disposed on the second side surface. 7. The backlight module with LEDs as claimed in claim 3, wherein the LEDs are disposed on the third side surface. 8. The backlight module with LEDs as claimed in claim 3, wherein the LEDs are disposed on the fourth side surface.

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