CN1285958C - Backlight module - Google Patents

Abstract

A backlight module suitable for providing a surface light source is mainly composed of a light guide plate, a light source, a reflector and a light compensation element. The light source is arranged beside the side surface of the light guide plate, light rays provided by the light source can enter the light guide plate from the side surface of the light guide plate and are transmitted to the top surface of the light guide plate to be emitted after passing through the bottom surface of the light guide plate, the reflecting cover is arranged beside the side surface of the light guide plate to cover the light source, and the light compensation element is arranged in the reflecting cover. The light compensation element arranged in the reflector or the reflector is directly provided with a plurality of reflecting surfaces to compensate the brightness of the light guide plate at two corners adjacent to two side ends of the light source.

Description

Backlight module

technical field

The utility model relates to a backlight module, and in particular to a backlight module capable of effectively compensating the brightness of two corners of a light guide plate adjacent to two sides of a light source.

Background technique

The rapid progress of the multimedia society is mostly due to the rapid progress of semiconductor components or man-machine display devices. As far as the display is concerned, the cathode ray tube (Cathode Ray Tube, CRT) has been monopolizing the display market in recent years because of its excellent display quality and economy. However, for the environment where individuals operate most terminals/display devices on the table, or from the perspective of environmental protection, if the trend of energy saving is predicted, cathode ray tubes still have many problems in terms of space utilization and energy consumption, and There is no effective solution to the demands of lightness, thinness, shortness, smallness and low power consumption. Therefore, liquid crystal displays (Liquid Crystal Display, LCD) with superior characteristics such as high image quality, increased space utilization efficiency, low power consumption, and no radiation have gradually become the mainstream of the market. It is worth noting that since the liquid crystal molecules themselves do not emit light, the surface light source required by the liquid crystal panel must be provided through the backlight module, so that the liquid crystal panel can achieve the display effect and obtain sufficient brightness and contrast.

FIG. 1 is a schematic top view of a conventional backlight module. FIG. 2 is a schematic side view of the backlight module of FIG. 1 . Please refer to FIG. 1 and FIG. 2 together. The backlight module 100 is mainly composed of a light guide plate 110 , a light source 120 , a reflector 130 and a frame 140 . Wherein, the light guide plate 110 is, for example, a wedge-shaped light guide plate, and the light guide plate 110 has a top surface 112, a bottom surface 114, and a side surface 116, wherein the top surface 112 is designed as a light-emitting surface, the bottom surface 114 is designed as a reflective surface, and the side surfaces 116 is designed as a light incident surface. The light source 120 is, for example, a cold-cathode fluorescent tube. The light source 120 is arranged beside the side surface 116 of the light guide plate 110, and the two ends of the light source 120 are fixed on a light source fixing seat 150. The light provided by the light source 120 can be transmitted by the light guide plate 110 The side surface 116 of the light guide plate 110 is incident on the light guide plate 110 , passes through the bottom surface 114 of the light guide plate 110 , and then is transmitted to the top surface 112 of the light guide plate 110 to exit. It can be seen from the above that the light emitted from the top surface 112 is in the form of a surface light source. The reflector 130 is disposed beside the side surface 116 of the light guide plate 110 to cover the light source 120 , and the light provided by the light source 120 can be concentratedly projected to the side surface 116 of the light guide plate 110 through the reflector 130 . In addition, the frame 140 is used to carry the above-mentioned light guide plate 110 , light source 120 and reflector 130 , so that the light guide plate 110 , light source 120 and reflector 130 can be integrated.

Based on the above, since most of the current light sources 120 use cold-cathode fluorescent tubes (CCFLs), and the brightness of the high and low-voltage areas at both ends of the cold-cathode fluorescent tubes is usually lower than the brightness of the middle section, the light guide plate 110 will be adjacent to both sides of the light source 120 The brightness of the two corners at the end (that is, the areas A and B shown in the figure) is too dark. However, in order to overcome the phenomenon that the brightness of the two corners of the light guide plate adjacent to the two sides of the light source is too dark, the known technology usually increases the length of the lamp tube so that the high and low voltage areas with insufficient brightness at both ends of the lamp tube extend outside the light guide plate. Although the brightness of the two corners of the light guide plate adjacent to the two sides of the light source can be increased in this way, the width of the left and right sides of the liquid crystal display will inevitably become longer, resulting in an increase in the overall volume. Such a design does not meet the light, thin, and Short, small trends.

Utility model content

Therefore, the purpose of this utility model is to provide a backlight module, by configuring a light compensation element in the reflector or directly forming a plurality of reflective surfaces on the reflector, to compensate for the two sides of the light guide plate adjacent to the light source. corner brightness, and still be able to meet the needs of LCD miniaturization.

Based on the above purpose, the utility model proposes a backlight module suitable for providing a side light source. The backlight module is composed of a light guide plate, a light source, a reflector and a light compensation element. Wherein, the light guide plate has a top surface, a bottom surface and at least one side surface. The light source is arranged beside the side of the light guide plate, and the light provided by the light source can enter the light guide plate from the side of the light guide plate, pass through the bottom surface of the light guide plate, and then transmit to the top surface of the light guide plate to exit. The reflection cover is arranged beside the side of the light guide plate to cover the light source. The light compensating element is arranged in the reflection cover, and the light compensating element has multiple reflective surfaces facing the two sides of the light source to compensate the brightness of two corners of the light guide plate adjacent to the two sides of the light source.

Also based on the above purpose, the utility model further proposes a backlight module, which is suitable for providing a side light source. The backlight module is composed of a light guide plate, a light source and a reflector. Wherein, the light guide plate has a top surface, a bottom surface and at least one side surface. The light source is arranged beside the side of the light guide plate, and the light provided by the light source can enter the light guide plate from the side of the light guide plate, pass through the bottom surface of the light guide plate, and then transmit to the top surface of the light guide plate to exit. The reflector is arranged beside the side of the light guide plate to cover the light source, and the reflector has a plurality of reflective surfaces, and these reflective surfaces face the two sides of the light source to compensate for the difference between the two corners of the light guide plate adjacent to the two sides of the light source. brightness.

According to a preferred embodiment of the present invention, the light guide plate is, for example, a wedge-shaped light guide plate, and the bottom surface of the light guide plate is, for example, a stepped surface or has a plurality of concave points for scattering the light provided by the light source. , and the light source is, for example, a cold cathode lamp.

According to the preferred embodiment of the present invention, the optical compensation element is composed of a first light guide and a second light guide, for example. Wherein, the first light guide body is arranged in the reflection cover, and the first light guide body has a first reflection surface, and the second light guide body is arranged in the reflection cover, and the second light guide body has a second reflection surface . The above-mentioned first reflective surface and the second reflective surface respectively face the two sides of the light source to compensate for the brightness of the two corners of the light guide plate adjacent to the two sides of the light source. In addition, the first reflective surface and the second reflective surface are, for example, a stepped surface or have a plurality of concave points.

According to the preferred embodiment of the present invention, the optical compensation element is composed of a first reflector and a second reflector, for example. Wherein, the first reflector and the second reflector are arranged in the reflector, and the first reflector and the second reflector are respectively facing the two sides of the light source, so as to compensate the brightness of the two corners of the light guide plate adjacent to the two sides of the light source presented. In addition, the first reflective plate and the second reflective plate are, for example, a stepped surface or have a plurality of concave points.

According to the preferred embodiment of the present invention, in order to enhance the luminance of the backlight module, a diffusion sheet and a brightness enhancement sheet can be further arranged. In this embodiment, for example, a diffusion sheet can be arranged on the top surface of the light guide plate, And a brightness enhancement sheet is arranged on the diffusion sheet. In addition, in order to integrate the light guide plate, light source, reflector and light compensation element in the backlight module, for example, a frame can be used to carry the light guide plate, light source, reflector and light compensation element.

Based on the above, the utility model arranges a light compensation element in the reflector or directly forms a plurality of reflective surfaces on the reflector to compensate the brightness of the two corners of the light guide plate adjacent to the two sides of the light source, so that the light guide plate A surface light source with uniform brightness can be provided, and still be able to meet the miniaturization requirement of the liquid crystal display.

Description of drawings

FIG. 1 is a schematic top view of a known backlight module;

FIG. 2 is a schematic side view of the backlight module of FIG. 1;

3 is a schematic top view of a backlight module according to a first embodiment of the present invention;

FIG. 4 is a schematic side view of the backlight module of FIG. 3; and

FIG. 5 is a schematic top view of a backlight module according to a second embodiment of the present invention.

100, 200, 300: backlight module

110, 210, 310: light guide plate

112, 212: top surface

114, 214: bottom surface

116, 216: side

120, 220, 320: light source

130, 230, 330: reflector

140, 240: frame

150, 250: light source holder

260: optical compensation element

332: reflective surface

Detailed ways

first embodiment

FIG. 3 is a schematic top view of the backlight module according to the first embodiment of the present invention. FIG. 4 is a schematic side view of the backlight module of FIG. 3 . Please refer to FIG. 3 and FIG. 4 together. The backlight module 200 is composed of a light guide plate 210 , a light source 220 , a reflector 230 , a frame 240 and a light compensation element 260 . The light guide plate 210 is, for example, a wedge-shaped light guide plate. The light guide plate 210 has a top surface 212, a bottom surface 214, and a side surface 216, wherein the top surface 212 is designed as a light-emitting surface, and the bottom surface 214 is designed as a reflective surface, such as a stepped shape. For example, the surface may have a plurality of concave points for scattering or reflecting the light provided by the light source 220 , and the side surface 216 is designed as a light incident surface.

The light source 220 is, for example, a cold-cathode fluorescent tube. The light source 220 is arranged beside the side surface 216 of the light guide plate 210, and the two ends of the light source 220 are fixed on a light source fixing seat 250. The light provided by the light source 220 can be transmitted by the light guide plate 210 The side surface 116 of the light guide plate 210 is incident on the light guide plate 210, passes through the bottom surface 214 of the light guide plate 210, and then is transmitted to the top surface 212 of the light guide plate 210 to exit. From the above, it can be known that the light emitted from the top surface 212 is a surface light source.

The reflector 230 is disposed beside the side surface 216 of the light guide plate 210 to cover the light source 220 , and the light provided by the light source 120 can be concentratedly projected onto the side surface 216 of the light guide plate 210 through the reflector 230 . In addition, in order to integrate the light guide plate 210, the light source 220, the reflector 230, and the optical compensation element 260 in the backlight module 200, for example, a frame 240 may be used to carry the light guide plate 210, the light source 220, the reflector 230, and the optical compensation element. 260.

Certainly, in order to enhance the luminance of the backlight module 200 , a diffusion sheet 270 and a brightness enhancement sheet 280 may be further configured. Wherein, the diffusion sheet 270 is, for example, disposed on the top surface 212 of the light guide plate 210 , and the brightness enhancement sheet 280 is, for example, disposed on the diffusion sheet 270 .

It is worth noting that in the present invention, an optical compensating element 260 is disposed in the reflector 230. The optical compensating element 260 is composed of, for example, two light guides. Each of the two light guides has a reflective surface 262, and the reflective surface 262 and The reflective surface 262 faces to both sides of the light source 220 respectively, and the reflective surface 262 is, for example, a stepped surface 262 a or has a plurality of concave points 262 b for scattering the light provided by the light source 220 . Since the reflective surface 262 of the light guide is designed to face the two sides of the light source 220, it can reflect or scatter the light with higher brightness in the middle section of the cold cathode lamp tube to the two corners of the light guide plate 210 adjacent to the two sides of the light source 220 (i.e. Regions C and D) shown in the figure are used to compensate the brightness of the two corners, so that the surface light source provided by the top surface 212 of the light guide plate 210 can achieve uniform brightness in each region. Of course, the light guides of the present invention are not limited to two as shown in FIG. 3 , and the two light guides can be integrated into a single component whose length is similar to that of the light source 220 .

In addition, those skilled in the art should know that the light compensating element of the present invention can be replaced by two reflectors (not shown in the figure). The plate is, for example, a stepped surface or has a plurality of concave points, so as to scatter the light provided by the light source, and also to compensate the brightness of the two corners of the light guide plate adjacent to the two sides of the light source.

second embodiment

FIG. 5 is a schematic top view of a backlight module according to a second embodiment of the present invention. Please refer to FIG. 5 , the overall structure of the backlight module 300 is roughly the same as that of the first embodiment, and the similarities will not be repeated here. The difference is that a plurality of reflective surfaces 332 are directly formed on the reflector 330 to replace the first embodiment. In the light compensating element in the example, these reflective surfaces 332 also face to the two sides of the light source 320 respectively, and the reflective surface 332 is, for example, a stepped surface (not shown in the figure) or has a plurality of concave points (not shown in the figure), for example. , so as to scatter the light provided by the light source 320 and also compensate the brightness of the two corners of the light guide plate 310 adjacent to both sides of the light source 320 (that is, the regions E and F shown in the figure).

To sum up, the backlight module of the present invention has at least the following advantages:

1. The backlight module of the present invention can compensate the brightness of the two corners of the light guide plate adjacent to the two sides of the light source, so that the surface light source provided by the top surface of the light guide plate can have uniform brightness in each area.

2. The backlight module of the present utility model can not only increase the brightness of the two corners of the light guide plate adjacent to the two sides of the light source, but will not increase the overall volume of the backlight module, and can still maintain the thin and short characteristics of the liquid crystal display .

Claims (14)

1. a backlight module is suitable for providing an area source, it is characterized in that, this backlight module comprises:

One light guide plate has an end face, a bottom surface and at least one side;

One light source is disposed at by this side of this light guide plate, and wherein the light that this light source provided can be by this this light guide plate of side incident, and is passed to this end face outgoing through behind this bottom surface;

One reflex housing is disposed at by this side of this light guide plate, to cover this light source; And

One optical compensation element is disposed in this reflex housing, and wherein this optical compensation element has a plurality of reflectings surface, and those reflectings surface are towards the two side ends of this light source, to compensate the brightness that this light guide plate is adjacent to two corners of this lamp source two side ends.

2. backlight module as claimed in claim 1 is characterized in that, this optical compensation element comprises:

One first light conductor is disposed in this reflex housing, and this first light conductor has one first reflecting surface; And

One second light conductor, be disposed in this reflex housing, and this second light conductor has one second reflecting surface, and wherein this first reflecting surface and this second reflecting surface are respectively towards the two side ends of this light source, to compensate the brightness that this light guide plate is adjacent to two corners of this lamp source two side ends.

3. backlight module as claimed in claim 2 is characterized in that, this first reflecting surface and this second reflecting surface are a step-like surface.

4. backlight module as claimed in claim 2 is characterized in that, has a plurality of concave points on this first reflecting surface and this second reflecting surface.

5. backlight module as claimed in claim 1 is characterized in that, this optical compensation element comprises:

One first reflecting plate is disposed in this reflex housing; And

One second reflecting plate is disposed in this reflex housing, and wherein this first reflecting plate and this second reflecting plate are respectively towards the two side ends of this light source, to compensate the brightness that this light guide plate is adjacent to two corners of this lamp source two side ends.

6. backlight module as claimed in claim 5 is characterized in that, this first reflecting plate and this second reflecting plate have a step-like surface.

7. backlight module as claimed in claim 5 is characterized in that, has a plurality of concave points on this first reflecting plate and this second reflecting plate.

8. backlight module as claimed in claim 1 is characterized in that, more comprises a framework, and this framework can carry this light guide plate, this light source, this reflex housing and this optical compensation element.

9. backlight module as claimed in claim 1 is characterized in that, more comprises a diffusion sheet and a brightening piece, and wherein this diffusion sheet is disposed on this end face of this light guide plate, and this brightening piece is disposed on this diffusion sheet.

10. a backlight module is suitable for providing an area source, it is characterized in that, this backlight module comprises:

One light guide plate has an end face, a bottom surface and at least one side;

One light source is disposed at by this side of this light guide plate, and wherein the light that this light source provided can be by this this light guide plate of side incident, and is passed to this end face outgoing through behind this bottom surface; And

One reflex housing is disposed at by this side of this light guide plate, and to cover this light source, wherein this reflex housing has a plurality of reflectings surface, and those reflectings surface are towards the two side ends of this light source, to compensate the brightness that this light guide plate is adjacent to two corners of this lamp source two side ends.

11. backlight module as claimed in claim 10 is characterized in that, those reflectings surface are a step-like surface.

12. backlight module as claimed in claim 10 is characterized in that, those reflectings surface have a plurality of concave points.

13. backlight module as claimed in claim 10 is characterized in that, more comprises a framework, more comprises a framework, this framework can carry this light guide plate, this light source, this reflex housing.

14. backlight module as claimed in claim 10 is characterized in that, more comprises a diffusion sheet and a brightening piece, wherein this diffusion sheet is disposed on this end face of this light guide plate, and this brightening piece is disposed on this diffusion sheet.

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