TWI283778B - Backlight module - Google Patents

Abstract

A backlight module of the present invention includes a light guide plate, at least a light source, and a color filter with a number of different color areas, and a drive device for driving the filter to move. The light guide plate has at least a light incident surface and a light emitting surface. The light source is adjacent to the light incident surface. The color filter can move between the light source and the light incident surface. The light emitted from the light source project one of the different color areas, then comes into the light guide plate.

Description

1283778 V. INSTRUCTION DESCRIPTION (1) Technical Field of the Invention The present invention relates to a backlight module, and more particularly to a backlight module capable of changing colors. [Prior Art] Since the liquid crystal of the liquid crystal display panel itself has no illuminating property, in order to achieve the display effect, a liquid crystal display panel, such as a backlight module, must be provided to the liquid crystal display panel, and its function is to provide the panel with a sufficient brightness and uniform distribution. light source.

The backlight module of 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 convert it into a surface light source with high luminance and uniformity. The light source may 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 displays, a backlight module with a point light source and a light guide plate needs to use a plurality of point light sources with different colors to select a desired color display by lighting different point light sources, but because of its use A point light source increases the cost of the backlight module.

The backlight module with the line source and the light guide plate is shown in the first figure and the second figure, and is disclosed in the Republic of China Patent No. 54 2360 announced on July 11, 2003. The backlight module 2 is disposed at the bottom of the liquid crystal module 1 to form a liquid crystal display 1. The backlight module 20 includes a light guiding component 21 made of a transparent substrate, a reflective layer 22, and a color changing layer. 26. A brightening layer 25 and a light source 23. The light guiding element 21 is a wedge-shaped light guiding plate having a light emitting surface at the top, a light guiding surface 212 at the bottom, a reflective layer 22 disposed at the bottom of the light guiding surface 212, and a light source 23 disposed at the light guiding element 21 Smooth surface 215 - side,

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5. Description of the Invention (2) The light source 23 is provided with an arc-shaped mirror 24 on the side of the light incident surface 2 1 5 away from the light guiding element 2 1 . The light guiding element 21 is integrally provided with a brightness enhancing layer 25 and a color changing layer 26 on the light emitting surface. The brightness enhancing layer 25 is composed of a plurality of optical particles 251. The outer surface of the plurality of optical particles 251 has a plurality of convex portions, and the color is changed. Layer 2 6 is blended with a predetermined colorant. The backlight module 20 can convert the white light X emitted by the light source 23 into a color pupil through the color changing layer 26, and the color pupil passes through the brightness enhancement layer 25 and emits light with a higher brightness light, however, Since the brightness enhancing layer 25 and the color changing layer 26 are both disposed on the light guiding element 21, the color cannot be changed once set, and it is difficult to achieve different color changes. In view of this, it is necessary to provide a backlight module that can be changed in color and at a lower cost. SUMMARY OF THE INVENTION An object of the present invention is to provide a backlight module that can change color and has a low cost. The backlight module of the present invention comprises a light guide plate, at least one light source, a color filter having a plurality of color regions, and a driving device for moving the color filter. The light guide plate is configured to guide a light beam emitted by the light source, and includes at least one light incident surface, a light exiting surface and a bottom surface; the at least one light source is configured to emit a light beam as a light source and disposed adjacent to the light incident surface of the light guide plate; The light sheet is movably disposed between the light source and the light incident surface of the light guide plate, and the light beam emitted by the light source is projected on one of the plurality of color regions of the color filter and then enters the light guide plate through the light incident surface. Compared with the prior art, since the backlight module of the present invention includes one

1283778

The color regions of the present invention are various color light groups; and the color filters of the present invention enter the light guide plate, and only a single one can be used, which can form a simple color light source, and can also convert the color of the color light source. The backlight is used to reduce costs. In the backlight module of the invention, as shown in the third and fourth figures, the backlight module includes a light source 51, a light guide plate 52, a frame 53, a color filter, and a driving device. The light source 51 is a point source such as a light-emitting diode for emitting a light beam. The light guide plate 52 guides the light source 51 to emit a light beam/converts it into a surface light source. The light guide plate 52 is formed in a flat plate shape and is made of a transparent material 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 light exit surface 522. The bottom surface 523 and the plurality of side surfaces 5 24 ° are used to receive the light beam emitted by the light source 51. The light exit surface 522 can be processed into a coarse sugar surface having a certain roughness. The bottom surface 523 of the light guide plate 52 is provided with a plurality of light scattering dots (not shown) to improve the brightness and uniformity of the light beam emitted from the light guide plate 52. The size of the dots is increased in a direction away from the light incident surface 5 2 1 and is spherical. The dots may also be cylindrical, square, pyramidal or other suitable shape. The dots may be distributed on the bottom surface 523 of the light guide plate 52 by printing or injection molding. Alternatively, a plurality of V-shaped grooves may be provided on the bottom surface 52 to replace the plurality of dots. The frame 53 includes a bottom plate 531 and three frames 532 protruding from the bottom plate 531. The three frames 532 define a space (not labeled) for receiving the light guide plate 52. The light source 51 is disposed on the bottom plate 531. The surface of the bottom plate 531 corresponding to the bottom surface 52 of the light guide plate is a reflective surface, and the three frames 5 3 2 and the light guide

Page 7 1283778 V. Description of invention (4) " The surface corresponding to the side of the board 5 2 4 is also a reflecting surface. The color filter 54 includes a plurality of color regions, 542 and 543, etc. The color regions 541, 542, and 543 are square patterns respectively corresponding to a positioning code pattern 5 8 , and the color filter 54 is movably The light source 51 is disposed between the light-incident surface 521 of the light guide plate 52, and the light beam emitted by the light source 51 is projected on one of the plurality of color regions 541, 542 or 543 of the color filter 54 and then enters the light-emitting surface 521. Light board 52. The driving device is disposed on the bottom plate 531, and includes two stators 55 (only one of which is shown) between the light source 51 and the light-incident surface 521 of the light guide plate 52, and respectively disposed on the stator 55. a turntable 56 and a drive motor 57'. The color filter 54 is wound around the turntable 56 and movable with the rotation of the turntable 56, so that the color filter 54 is movably disposed on the bottom plate of the frame 53. 531. One of the turntables 56 can be driven by the drive motor 57. Referring to the fifth figure together, in order to accurately perform color selection and transformation, the positioning code pattern 58 can be interpreted by the clamping device (not shown), and the read signal is returned to the driving device, and the driving device is returned. The color filter 54 is driven such that one of the color regions 541, 542, 543 (shown as the color region 542) conforming to the desired color is located between the light source 51 and the light incident surface 521. The light ray 511 emitted by the light source 51 is all projected onto the color area 542, and after passing through the color area 542, it enters the light guide plate 52 through the illuminating surface 52 in a specific color. Of course, the light ray 511 emitted by the light source 51 can also be projected simultaneously on two or more of the plurality of color regions to achieve more color variations. Since the backlight module of the present invention includes a color having a plurality of color regions

Page 8 1283778 V. Invention Description (5) Color filter 'which can convert a simple light source into various colored light into the light guide plate' thus forming a backlight module of different colors; and because the present invention uses only a single white light source It can also reduce costs. The backlight module of the present invention may have other modified designs, for example: the light source may be a line source such as a cold cathode lamp; the light incident surface of the light guide plate may be subjected to electron beam evaporation or chemical vapor deposition. An anti-reflection film is coated, and the light-emitting surface may be an atomized surface or a plurality of regularly distributed scattering dots; the shape of the light guide plate may also be a wedge shape; the color regions of the color filter may also be circular or elliptical in shape. The grating filter of the shape; the side of the light-emitting surface of the light guide plate may further be provided with a cymbal, a diffusion plate and a cymbal. In summary, the invention has indeed met the requirements for the patent for the month of delivery, and has filed a patent application in accordance with the law. However, the above description is only a preferred embodiment of the invention, and any equivalent modifications or variations made by those skilled in the art of the present invention should be included in the following claims.

1283778 BRIEF DESCRIPTION OF THE DRAWINGS The first figure is a schematic view of the vertical structure of a liquid crystal display having a prior art optically variable light guiding element. The second figure is a schematic diagram of the optical path of the liquid crystal display shown in the first figure. The third figure is an exploded perspective view of the backlight module of the present invention. The fourth figure is an assembled view of the backlight module of the present invention. The fifth figure is a schematic diagram of the optical path of the backlight module of the present invention.

[Description of component symbols] Backlight module 5 Light source 51 Light guide plate 52 Light incident surface 521 Light exit surface 522 Bottom surface 523 Side surface 524 Frame 53 Base plate 531 Border 532 Color filter 54 Color area 541, 542 > 543 Stator 55 Turntable 56 Drive motor 57 positioning code pattern 58

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Claims (1)

1283778 VI. Patent application scope 1 · A back light module, a light source, and a light guide plate, which are included in at least one of the inlets and the one that has a driving force on the beam projection surface. The system is cold and yin 4. If the application frame is framed, the source is provided with the bottom plate. 5. If the application light source corresponds to a plurality of color light sources and is guided to the color light guide plate device, the patent range is used. Patent range Aurora tube. Patent Range Frames The two sides are on the bottom plate. The patent scope includes two sets of one turntable and one drive and one turn with the turntable, which includes: for emitting a light beam; ΓΊ: a light beam emitted, the light guide plate package; a front surface and a bottom surface, the input The color of the smooth surface area, the soil μ ^ ^ ^ Λ . The core first piece, which is movably set between the color fishing rods, the light emitted by the light source. f Move the color filter. The backlight module of the invention, wherein the backlight module of the light source is the light source=1, and the further package comprises a bottom plate and three protrusions on the bottom plate. The frame encloses a space for accommodating the light guide plate, wherein the color filter is movably disposed in the backlight module of the fourth item, and the stator on the bottom plate of the driving device is respectively sleeved on the stator The moving motor 'the color filter is wound and moved on the turntable, and the driving motor can drive the turntable The invention relates to a backlight module as claimed in claim 1, wherein the light emitting surface is an atomizing surface. 7. The backlight module of claim 1, wherein the light exiting surface is provided with a plurality of regularly distributed scattering dots. 8. The backlight module of claim 1, wherein the light incident surface is coated with an anti-reflection film. 9. The backlight module of claim 1, further comprising a diffusing plate on a side of the light-emitting surface of the light guide plate. The backlight module of claim 1, further comprising a prism sheet on a side of the light-emitting surface of the light guide plate. 11. The backlight module of claim 4, wherein the surface of the bottom plate corresponding to the bottom surface of the light guide plate is a reflective surface. The backlight module of claim 4, wherein the surface of the frame corresponding to the side of the light guide plate is a reflective surface. The backlight module of claim 1, wherein the plurality of color regions of the color filter are grating filters. The backlight module of claim 1, wherein each color region of the color filter has a square shape. The backlight module of claim 1, wherein each color region of the color filter has a circular shape. The backlight module of claim 1, wherein each color region of the color filter has an expanded circular shape. The backlight module of claim 1, wherein each color region of the color filter comprises a positioning code pattern. Page 12 1283778 Page 13