CN100370327C - Backlight module - Google Patents

Abstract

The invention discloses a backlight module, which includes a light guide plate, at least one light source, a color filter with multiple color regions and a driving device for moving the color filter. The light guide plate includes at least one light incident surface, a light exit surface and a bottom surface, the at least one light source is arranged adjacent to the light incident surface of the light guide plate, and the color filter is movably arranged between the light source and the light incident surface of the light guide plate During this period, the light beam emitted by the light source is projected on one of the multiple color regions of the color filter and then enters the light guide plate through the light incident surface.

Description

Backlight module

【Technical field】

The invention relates to a backlight module, in particular to a color-changeable backlight module.

【Background technique】

Since the liquid crystal itself of the liquid crystal display panel does not have light-emitting characteristics, in order to achieve the display effect, it is necessary to provide a light source system for the liquid crystal display panel, such as a backlight module, whose function is to provide the panel with a surface light source with sufficient brightness and uniform distribution.

The backlight module in the prior art is mainly composed of a light source and a light guide plate. The function of the light guide plate is to guide the transmission direction of the light emitted by the light source and transform it into a surface light source with high brightness and uniformity. The light source can be a point light source such as a light emitting diode, or a line light source such as a cold cathode lamp.

In order to meet the needs of multiple color display, the backlight module with point light source and light guide plate needs to use multiple point light sources with different colors, and select the required color display by lighting different point light sources. However, using multiple The point light source will increase the cost of the backlight module.

A backlight module using a line light source and a light guide plate is shown in FIGS. 1 and 2 , which was disclosed in Taiwan Patent No. 542360 published on July 11, 2003. The backlight module 20 is arranged on the bottom of the liquid crystal module 10 to form the liquid crystal display 1. The backlight module 20 includes a light guide element 21 made of a light-transmitting substrate, a reflective layer 22, a color-changing layer 26, and a light-enhancing layer. Bright layer 25 and light source 23. The light guide element 21 is a wedge-shaped light guide plate with a light-emitting surface (not shown) on the top and a light-guiding surface 212 at the bottom. The reflective layer 22 is arranged on the bottom of the light-guiding surface 212. On the light incident surface 215 side of the component 21 , and the light source 23 is provided with an arc-shaped reflector 24 on the light incident surface 215 side away from the light guide component 21 . The light-guiding element 21 is integrally provided with a color-changing layer 26 and a brightness-enhancing layer 25 on the light-emitting surface, and the brightness-enhancing layer 25 is composed of a plurality of optical particles 251, and the outer surfaces of the plurality of optical particles 251 have a plurality of protrusions, The color-changing layer 26 is mixed with a predetermined coloring material.

The backlight module 20 can convert the white light X emitted by the light source 23 into colored light Y through the color-changing layer 26. 26 and the brightness enhancement layer 25 are integrally arranged on the light guide element 21, once the color is set, it cannot be changed, and it is difficult to change different colors.

【Content of invention】

In order to overcome the problem that the backlight module in the prior art is difficult to change different colors, the present invention provides a backlight module with changeable colors.

The technical solution adopted by the present invention to solve the technical problem is to provide a backlight module, which includes a light guide plate, at least one light source, a color filter with multiple color regions, and a color filter for moving the color filter. drive unit. The light guide plate includes at least one light incident surface, a light exit surface and a bottom surface, the at least one light source is arranged adjacent to the light incident surface of the light guide plate, and the color filter is movably arranged between the light source and the light incident surface of the light guide plate During this period, the light beam emitted by the light source is projected on one of the multiple color regions of the color filter and then enters the light guide plate through the light incident surface. The driving device is used to move the color filter, and the driving device further includes two stators 1. Two turntables and a drive motor respectively sleeved on the stator. The color filter is wound on the turntable and can move with the rotation of the turntable. The drive motor can drive one of the turntables.

Compared with the prior art, since the backlight module of the present invention includes a color filter with multiple color regions, the light emitted by the light source with a single color can be converted into various colored lights and enter the light guide plate, thus forming different colors. color backlight module; and because the present invention only uses a single color light source, the cost can also be reduced.

【Description of drawings】

FIG. 1 is a schematic perspective view of a liquid crystal display with an optically variable light guide element in the prior art.

FIG. 2 is a schematic diagram of the optical path of the liquid crystal display shown in FIG. 1 .

FIG. 3 is an exploded perspective view of the backlight module of the present invention.

FIG. 4 is a three-dimensional assembly view of the backlight module of the present invention.

FIG. 5 is a schematic diagram of the optical path of the backlight module of the present invention.

【Detailed ways】

The backlight module of the present invention is shown in FIGS. 3 and 4 . The backlight module 5 includes a light source 51 , a light guide plate 52 , a frame 53 , a color filter 54 and a driving device (not shown). The light source 51 is a point light source such as a light emitting diode, which is used to emit white light beams. The light guide plate 52 guides the transmission direction of the light beams emitted by the light source 51 and converts them into surface light sources.

The light guide plate 52 is flat and made of transparent materials such as acrylic, glass or polycarbonate, and includes a light incident surface 521, a light exit surface 522 connected to the light incident surface 521, and a bottom surface opposite to the light exit surface 522. 523 and a plurality of sides 524. The light incident surface 521 is used for receiving the light beam emitted by the light source 51 . The light emitting surface 522 can be processed into a rough surface with a certain roughness. The bottom surface 523 of the light guide plate 52 is provided with a plurality of light scattering dots (not shown in the figure), so as to improve the brightness and uniformity of the light beam emitted from the light guide plate 52 . The size of the dots increases along the direction away from the light incident surface 521 , and is spherical. The dots can also be in the shape of a cylinder, a cube, a pyramid or other suitable shapes. The dots can be distributed on the bottom surface 523 of the light guide plate 52 by printing or injection molding. In addition, a plurality of V-shaped grooves may be provided on the bottom surface 523 instead of the plurality of dots.

The frame 53 includes a base plate 531 and three frames 532 protruding from the base plate 531. The three frames 532 enclose a space (not shown) for accommodating the light guide plate 52. The light source 51 is arranged on the base plate 531. The surface of the bottom plate 531 corresponding to the bottom surface 523 of the light guide plate is a reflective surface, and the surfaces of the three frames 532 corresponding to the side surfaces 524 of the light guide plate are also reflective surfaces.

The color filter 54 includes a variety of color regions 541, 542 and 543, etc., the color regions 541, 542 and 543 are square patterns, which correspond to a positioning code pattern 58 respectively, and the color filter 54 is movably arranged Between the light source 51 and the light incident surface 521 of the light guide plate 52, the light beam emitted by the light source 51 is projected on one of the multiple color areas 541, 542 or 543 of the color filter 54 and enters the light guide plate through the light incident surface 521 52.

The driving device is arranged on the bottom plate 531, which includes two stators 55 (only one of which is shown in the figure) located between the light source 51 and the light incident surface 521 of the light guide plate 52, and two turntables 56 respectively sleeved on the stators 55. and a driving motor 57 , the color filter 54 is wound on the turntable 56 and can move with the rotation of the turntable 56 , so that the color filter 54 is movably arranged on the bottom plate 531 of the frame 53 . One of the two turntables 56 can be driven by a drive motor 57 .

Referring to FIG. 5 together, in order to accurately select and change colors, a positioning device (not shown) can be used to interpret the positioning code pattern 58, and the interpreted signal is fed back to the driving device, which drives the color filter 54 , making one of the color areas 541 , 542 , and 543 (shown as the color area 542 ) matching the required color be located between the light source 51 and the light incident surface 521 . The light 511 emitted by the light source 51 will all be projected on the color region 542 , and after being filtered by the color region 542 , enter the light guide plate 52 through the light incident surface 521 in a specific color. Of course, the light 511 emitted by the light source 51 can also be projected on two or more of the multiple color areas 541 , 542 , 543 at the same time, so as to realize more color changes.

Since the backlight module of the present invention includes a color filter 54 with multiple color regions 541, 542, 543, it can convert the light of the pure color light source 51 into various colored lights and enter the light guide plate 52, thereby making the backlight The modules 5 form different colors; and because the present invention only uses a single white light source, the cost can be reduced.

The backlight module of the present invention can have the following other modified designs, for example:

The light source 51 can be a line light source such as a cold cathode lamp;

An anti-reflection film can be coated on the light incident surface 521 of the light guide plate 52 by electron beam evaporation or chemical vapor deposition, and the light exit surface 522 can be an atomized surface or a plurality of regularly distributed scattering dots;

The shape of the light guide plate 52 can also be wedge-shaped;

The shape of each color region 541, 542, 543 of the color filter 54 can also be a circular or elliptical grating filter;

A prism sheet, a diffuser sheet, and a prism sheet may be further disposed on the side of the light-emitting surface 522 of the light guide plate 52 in sequence.

Claims (9)

1. module backlight, it comprises an at least one light source and a light guide plate, this light guide plate comprises at least one incidence surface, one exiting surface and a bottom surface, this incidence surface is corresponding with this light source, it is characterized in that: this module backlight comprises that further a drive unit and has the colored filter in multicolour zone, this colored filter is arranged between this light source and the light guide plate incidence surface, the light beam that this light source sent is incident upon one of this colored filter multicolour zone after incidence surface enters light guide plate, this drive unit is in order to move this colored filter, this drive unit further comprises two stators, be enclosed within two rotating disks and a CD-ROM drive motor on this stator respectively, this colored filter is wound on the rotating disk and can moves with the rotation of rotating disk, and this CD-ROM drive motor can drive one of this rotating disk.

2. module backlight according to claim 1 is characterized in that: this light source is light emitting diode or cold cathode fluorescent lamp.

3. module backlight according to claim 1, it is characterized in that: this module backlight further comprises a framework, this framework comprises a base plate and three frames that are projected on this base plate, these three frames surround a space of accommodating this light guide plate, this light source is arranged on this base plate, and this colored filter is arranged on this base plate movably.

4. module backlight according to claim 1 is characterized in that: this exiting surface is atomization surface or the scattering netted dot that is provided with a plurality of regular distribution.

5. module backlight according to claim 1 is characterized in that: this module backlight further comprises a prismatic lens, a diffuser plate and a prismatic lens that is positioned at light guide plate exiting surface one side and is provided with in regular turn.

6. module backlight according to claim 3 is characterized in that: the corresponding surface of this base plate and bottom surface of light guide plate is a reflecting surface, and the corresponding surface of this frame and light guide plate side is a reflecting surface.

7. module backlight according to claim 1 is characterized in that: the multicolour zone of this colored filter is grating filter.

8. module backlight according to claim 1 is characterized in that: each color region shape of this colored filter is square, circular or oval.

9. module backlight according to claim 1, it is characterized in that: this module backlight further comprises a location device, each color area of this colored filter comprises a location coding pattern respectively, but the location coding pattern of this each color area of locating device interpretation, and the signal that institute's interpretation is gone out feeds back to drive unit.

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