TWI428672B - Backlight module - Google Patents

Description

Backlight module

The invention relates to a backlight module.

FIG. 1 is a schematic cross-sectional view of a backlight module 100 without a color compensation microstructure. As shown in FIG. 1 , the backlight module 100 includes a cover 102 , a light bar 104 , and at least one light emitting diode 106 disposed on the surface of the light bar 104 . The light bar 104 is disposed in the cover body 102 so as to be substantially parallel to the light incident surface 110a of the light guide plate 110. The partial light beam emitted from the light emitting diode 106 is reflected by the reflective layers 108 on both sides and enters the front end of the light guide plate 110. As shown in the light path of FIG. 2, since the large-angle light beam Iy emitted from the light-emitting diode 106 has a yellowish color shift phenomenon, the small-angle light beam Ib emitted from the light-emitting diode 106 has a bluish color shift phenomenon. The angle α of the yellowish light beam Iy incident on the light guide plate 110 is about 35 to 80 degrees, so that the yellow light beam Iy is reflected more than the blue light beam Ib in the same distance, so the yellow light is mainly concentrated on the light guide plate 110. The front end reflects the yellow color of the front end of the light guide plate 110.

U.S. Patent No. 6,345,899 discloses a backlight module in which a yellow and blue ink droplet distribution is formed on the surface of the reflective sheet to compensate for different reflectances of the beams of different wavelengths on the reflective sheet and different scattering rates in the light guide plate. The resulting backlight module is uneven in color.

Taiwan Patent Publication No. TW200700834 discloses a backlight module in which a lower layer of a light guide plate forms an ink layer having color-shifting particles, and the color-shifting particles can absorb red light and green light to provide a color shift compensation effect. However, this design cannot solve the problem that the color of the front end of the light guide plate is yellowish and the overall color uniformity of the backlight module is poor.

The invention provides a backlight module with good picture color uniformity.

Other objects and advantages of the present invention will become apparent from the technical features disclosed herein. To achieve one or a part or all of the above or other purposes, an embodiment of the present invention provides a backlight module including a light guide plate, at least one light emitting element, and a plurality of color compensation microstructures. The light guide plate has at least one light incident surface, and a bottom surface and a light exit surface which are connected to the light surface and are oppositely disposed. The light emitting element is disposed adjacent to the light incident surface, and the light emitting element includes at least one light source that emits white light. The large-angle beam emitted by the point source has a yellowish color shift phenomenon, and the color compensation microstructure is distributed on a section of the light guide plate adjacent to the light incident surface and is adapted to absorb yellow light.

In one embodiment, the color compensation microstructure is formed on at least one of the bottom surface and the light exit surface.

In one embodiment, each of the color compensation microstructures is a blue dot.

In one embodiment, each of the color compensation microstructures comprises dyed colloids or colored scattering particles.

Another embodiment of the present invention provides a backlight module including a light guide plate, a first light emitting element, a second light emitting element, a plurality of first color compensation microstructures, and a plurality of second color compensation microstructures. The light guide plate has a first light incident surface and a second light incident surface, and a bottom surface and a light exit surface disposed opposite to each other, and the bottom surface and the light exit surface are connected to the first light incident surface and the second light incident surface. The first light-emitting element is disposed adjacent to the first light-incident surface, and the first light-emitting element includes at least one light source that emits white light, and the large-angle light beam emitted by the point light source has a yellowish color shift phenomenon. The second illuminating element is disposed adjacent to the second light incident surface, and the second illuminating element comprises at least one light source that emits white light, and the large angle light beam emitted by the point light source has a yellowish color shift phenomenon. The light guide plate includes a first segment adjacent to the first light incident surface, a second segment adjacent to the second light incident surface, and a third segment between the first segment and the second segment. The first color compensation microstructure is distributed on the first segment and the second segment of the light guide plate, and the first color compensation microstructure is adapted to absorb yellow light. The second color compensation microstructure is distributed over the third section of the light guide plate, and the second color compensation microstructure is adapted to absorb blue light.

In one embodiment, the color compensation microstructure is formed on at least one of the bottom surface and the light exit surface.

In one embodiment, each of the first color compensation microstructures is a blue dot, and each of the second color compensation microstructures is a yellow dot.

In one embodiment, each of the color compensation microstructures comprises dyed colloids or colored scattering particles.

Another embodiment of the present invention provides a backlight module including a light guide plate, at least one light emitting element, and a plurality of color compensation microstructures. The light guide plate has at least one light incident surface and a bottom surface and a light exit surface which are oppositely disposed to be connected to the light surface. The light emitting element is disposed adjacent to the light incident surface, and the color compensation microstructure is formed on at least one of the bottom surface and the light emitting surface. The color compensation microstructure is adapted to absorb a particular wavelength of light emitted by the light emitting element to cause the backlight module to display a color pattern or color text.

In summary, the backlight module of the embodiment of the present invention has at least one of the following advantages: by the design of the above embodiment, the first color compensation microstructure is adapted to absorb yellow light to adjust the picture of the backlight module adjacent to the light source end. In order to approach the white screen, by setting the first color compensation microstructure, the color shift phenomenon can be effectively improved and the color uniformity of the entire screen of the backlight module can be improved. Furthermore, a second color compensation microstructure can be additionally provided to absorb the blue light, so that the intermediate picture of the backlight module is adjusted to be close to the white picture, thereby further improving the color uniformity of the overall picture of the backlight module. On the other hand, using different color color compensation microstructures and adjusting their position distribution allows the backlight module to display colored text and patterns to provide special visual effects.

Other objects and advantages of the present invention will become apparent from the technical features disclosed herein. The above and other objects, features, and advantages of the invention will be apparent from

The foregoing and other technical aspects, features, and advantages of the present invention will be apparent from the Detailed Description of the <RTIgt; The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, etc., are only directions referring to the additional drawings. Therefore, the directional terminology used is for the purpose of illustration and not limitation.

FIG. 3 is a schematic diagram of a backlight module according to an embodiment of the invention. As shown in FIG. 3 , the backlight module 10 includes a light guide plate 12 , a first light emitting element 14 , and a second light emitting element 16 . The light guide plate 12 has a bottom surface 12a and a light exit surface 12b disposed opposite to each other, and a first light incident surface 12c and a second light incident surface 12d disposed opposite to each other. The bottom surface 12a connects the first light incident surface 12c and the second light incident surface 12d, and the light exit surface 12b connects the first light incident surface 12c and the second light incident surface 12d. The first light emitting element 14 is disposed adjacent to the first light incident surface 12c, and the first light emitting element 14 may include at least one light source that emits white light. The second light emitting element 16 is disposed adjacent to the second light incident surface 12d, and the second light emitting element 16 may include at least one light source that emits white light. The first light-emitting element 14 and the second light-emitting element 16 can be, for example, a light-emitting diode light bar. In general, the yellowish light beam is mainly concentrated on the front end of the light guide plate 12 adjacent to the light source, so that the front end of the light guide plate 12 is yellowish. Therefore, in the double-sided light-emitting backlight module 10 shown in FIG. 3, the color shift phenomenon in which both sides of the screen of the backlight module 10 are yellowish and the middle is bluish is easily generated. In other words, the light guide plate 12 may include adjacent a first section 121 of the light incident surface 12c, a second section 122 adjacent to the second light incident surface 12d, And a third section 123 located between the first section and the second section, the first section 121 and the second section 122 are prone to a yellowish color shift phenomenon and the third section 123 is prone to bluish The phenomenon of color shift. Therefore, in the present embodiment, a plurality of microstructures 22 are formed on the light guide plate 12, and portions of the microstructures 22 are the first color compensation microstructure 22a and partially the second color compensation microstructure 22b. The plurality of first color compensation microstructures 22a are distributed on the first section 121 and the second section 122 of the light guide plate 12, and the plurality of second color compensation microstructures 22b are distributed on the third section 123 of the light guide plate 12. . The first color compensation microstructure 22a is adapted to absorb yellow light to adjust the color of the two sides of the backlight module 10 to be a white picture, and the second color compensation microstructure 22b is adapted to absorb blue light to color the middle picture of the backlight module 10. Adjust to be close to the white screen. Therefore, by setting the color compensation microstructures 22a, 22b, the color shift phenomenon can be effectively improved and the color uniformity of the overall screen of the backlight module 10 can be improved. The color compensating microstructures 22a, 22b may, for example, comprise dyed colloids or colored scattering particles. When a dye or any material having a absorbing part of the color (specific wavelength of light) is added to the colloid of the dot ink, after the light beam passes through the dyed colloid, part of the color (specific wavelength of light) is changed by the absorption of the dyed colloid, but The color shift is compensated back to white light. Since blue and yellow are complementary colors, for example, the first color compensation microstructure 22a can be a blue dot to absorb yellow light, and the second color compensation microstructure 22b can be a yellow dot to absorb blue light. Alternatively, the color compensating microstructures 22a, 22b may comprise color scattering particles, and the color scattering particles have the effect of absorbing part of the color (specific wavelength of light) and scattering when the beam touches the color scattering particles. At this time, the color shift can be compensated back to white light and scattered out of the light guide plate 12. Further, the manufacturing method of the color compensation microstructures 22a and 22b is not limited, and may be formed on the light guide plate 12 by, for example, an inkjet method or a screen printing method. Through the inkjet process, the size of the local dot can be fine-tuned, and the ink of different colors and concentrations can be used to control the effect of color shift compensation, and the color and uniformity can be optimized by using multiple ink jets; the screen printing method can be different colors. The dots are printed multiple times with different stencils, and the effect of the color shift compensation of the screen can be controlled by the dot size, ink color and density.

4 is a schematic diagram of a backlight module according to another embodiment of the present invention. As shown in FIG. 4 , the backlight module 30 can be a single-side light-emitting backlight module 30 and has a light-emitting element 14 . The light-emitting element 14 is disposed adjacent to the light-incident surface 12c, and a plurality of microstructures 22 are formed on the bottom surface 12a. A portion of the plurality of microstructures 22 may be the first color compensation microstructure 22a, and the first color compensation microstructure 22a is disposed on a portion of the light guide plate 12 adjacent to the light incident surface 12c to absorb yellow light. The color compensation micro-structures 22a and 22b are not limited to be formed on the bottom surface 12a. For example, as shown in the backlight module 40 of FIG. 5, the color compensation micro-structures 22a and 22b may be formed on the light-emitting surface 12b or simultaneously formed on the bottom surface of the light guide plate 12. 12a and the light-emitting surface 12b are also available.

Moreover, in addition to providing the effect of color compensation, using different color compensation crystal structures and adjusting the position distribution thereof, a backlight module can display colored characters and patterns to provide special visual effects, for example, can be applied to advertising signs, Indicators, color light walls, color guide tiles, color lamps, etc.

In summary, the above embodiments of the present invention have at least one of the following advantages.

Since the first color compensation microstructure 22a is adapted to absorb yellow light to adjust the picture of the backlight module adjacent to the light source end to be close to the white picture, the first color compensation microstructure 22a can effectively improve the color shift phenomenon and improve the backlight module as a whole. The color uniformity of the picture. Furthermore, the second color compensation microstructure 22b can be additionally provided to absorb blue light, so that the intermediate picture of the backlight module is adjusted to be close to the white picture, thereby further improving the color uniformity of the overall picture of the backlight module. On the other hand, using different color color compensation microstructures and adjusting their position distribution allows the backlight module to display colored text and patterns to provide special visual effects.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent. In addition, any of the objects or advantages or features of the present invention are not required to be achieved by any embodiment or application of the invention. In addition, the abstract sections and headings are only used to assist in the search of patent documents and are not intended to limit the scope of the invention.

10, 30, 40‧‧‧ backlight module

12‧‧‧Light guide plate

121‧‧‧The first section of the light guide

122‧‧‧The second section of the light guide

123‧‧‧Lightguide third section

12a‧‧‧ bottom

12b‧‧‧Glossy

12c‧‧‧ first light surface

12d‧‧‧Second entrance

14‧‧‧First light-emitting element

16‧‧‧Second light-emitting element

22‧‧‧Microstructure

22a‧‧‧First color compensation microstructure

22b‧‧‧Second color compensation microstructure

100‧‧‧Light source module

102‧‧‧ Cover

104‧‧‧Light strips

106‧‧‧Lighting diode

108‧‧‧reflective layer

110‧‧‧Light guide plate

110a‧‧‧Into the glossy side

Iy‧‧‧Yellow white light

Ib‧‧‧Bluish white light

‧‧‧‧ angle

1 is a schematic cross-sectional view of a backlight module without a color compensation microstructure.

2 is a schematic view showing an optical path of the backlight module of FIG. 1.

FIG. 3 is a schematic diagram of a backlight module according to an embodiment of the invention.

4 is a schematic diagram of a backlight module according to another embodiment of the present invention.

FIG. 5 is a schematic diagram of a backlight module according to another embodiment of the present invention.

10‧‧‧Backlight module

12‧‧‧Light guide plate

121‧‧‧The first section of the light guide

122‧‧‧The second section of the light guide

123‧‧‧Lightguide third section

12a‧‧‧ bottom

12b‧‧‧Glossy

12c‧‧‧ first light surface

12d‧‧‧Second entrance

14‧‧‧First light-emitting element

16‧‧‧Second light-emitting element

22‧‧‧Microstructure

22a‧‧‧First color compensation microstructure

22b‧‧‧Second color compensation microstructure

Claims (14)

A backlight module includes: a light guide plate having at least one light incident surface; and a bottom surface and a light emitting surface connected to the light incident surface; and at least one light emitting element disposed adjacent to the light incident surface The light-emitting element includes at least one light source that emits white light, wherein the large-angle light beam emitted by the point light source has a yellowish color shift phenomenon; and a plurality of color compensation microstructures are distributed only in a region of the light guide plate adjacent to the light incident surface On the segment, and the color compensation microstructures are only suitable for absorbing yellow light. The backlight module of claim 1, wherein the color compensation microstructures are formed on at least one of the bottom surface and the light exit surface. The backlight module of claim 1, wherein each of the color compensation microstructures is a blue dot. The backlight module of claim 1, wherein each of the color compensation microstructures comprises a dyed colloid. The backlight module of claim 1, wherein each of the color compensation microstructures comprises color scattering particles. The backlight module of claim 1, wherein the color compensation microstructures are formed on the light guide plate by inkjet or screen printing. The backlight module of claim 1, wherein the light emitting element is a light emitting diode light strip. A backlight module comprising: a light guide plate having a first light incident surface and a second light incident surface, and a bottom surface and a light emitting surface disposed opposite to each other, wherein the bottom surface and the light emitting surface are connected to the first light incident surface and the light incident surface a second light-incident surface; a first light-emitting element disposed adjacent to the first light-incident surface, and the first light-emitting element includes at least one light source that emits white light, wherein the large-angle light beam emitted by the point light source has a yellowish a color-shifting phenomenon; a second light-emitting element disposed adjacent to the second light-incident surface, and the second light-emitting element includes at least one light source that emits white light, wherein the large-angle light beam emitted by the point light source has a yellowish a color shifting phenomenon, the light guide plate includes a first segment adjacent to the first light incident surface, a second segment adjacent to the second light incident surface, and the first segment and the second segment a third segment; a plurality of first color compensation microstructures distributed only on the first segment and the second segment of the light guide plate, and the first color compensation microstructures are only suitable for absorption Yellow light; and a plurality of second colors Compensation microstructures distributed only on the third section of the light guide plate, and the plurality of second color compensation microstructure only adapted to absorb blue light. The backlight module of claim 8, wherein the first color compensation microstructures and the second color compensation microstructures are formed on at least one of the bottom surface and the light exit surface. The backlight module of claim 8, wherein each of the first color compensation microstructures is a blue dot, and each of the second color compensation microstructures is a yellow Color dot. The backlight module of claim 8, wherein each of the first color compensation microstructures and each of the second color compensation microstructures comprises a dye colloid. The backlight module of claim 8, wherein each of the first color compensation microstructures and each of the second color compensation microstructures comprise color scattering particles. The backlight module of claim 8, wherein the first color compensation microstructures and the second color compensation microstructures are formed on the light guide plate by inkjet or screen printing. The backlight module of claim 8, wherein the first light-emitting element and the second light-emitting element are respectively a light-emitting diode light strip.