TW200424694A - A brightness-enhancement diffuser film - Google Patents

Abstract

A brightness-enhancement diffuser film applied in backlight modules includes at least a plastic material made of polyethylene terephthalate (PET), a optical bleaching agent and a optical brightness agent. The optical bleaching agent is a planar structure with a conjugated double bond and has at least an electron donor. The optical brightness agent is a methicone. The thickness of the brightness-enhancement-diffuser film ranges between 0.05mm and 0.6mm and the brightness-enhancement diffuser film is disposed on the surface of the light guide plate by means of the attachment of static electricity or the adhesion of a back coating glue. Lights become uniform after passing through the brightness-enhancement diffuser film. The brightness-enhancement diffuser film of the present invention can decrease the usage of the diffuser and the prism of the multi-layer optical thin film in a conventional backlight module and improve the brightness performance of the backlight module.

Description

200424694 V. Description of the invention (l) [Technical field to which the invention belongs] The present invention relates to a light-increasing diffusion film, and more particularly to a light-increasing diffusion film that can be applied to a backlight module. [Prior art]

With the rapid progress of Thin Film Transistor Liquid Crystal Display (TFT_LCD) manufacturing technology, and its advantages of lightness, thinness, power saving, and no radiation, liquid crystal displays (LCDs) have been widely used. It is used in various electronic products such as mobile phones, personal digital assistants (PDAs), notebook computers, digital cameras and camcorders. Please refer to FIG. 1, which shows a partial cross-sectional view of a conventional side-type backlight module. In FIG. 1, the backlight module 10 includes at least a light guide plate 11, a reflective sheet 12, a light source 13, and a multilayer optical film. l4 and a frame 15. The light guide plate 11 has a light emitting surface 11a, a lower surface lib, and an upright side surface lie.

The upright side 11 c is connected to the light emitting surface 1 1 a and the lower surface 11 b. The light source 1 3 is arranged beside the upright side 11 c, and guides light into the light guide plate 11 by means of end face illumination. The light source 13 may be a cold cathode fluorescent lamp (CCFL) or a lamp tube. The reflection sheet 12 is disposed under the light guide plate 11 to reflect light to the inside of the light guide plate U to increase the light utilization rate of the backlight module 10. Multilayer optical film 丨 4 series arranged on the light emitting surface

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Composed of diffusion sheet and prism sheet, frame 15 is used to fix the above components. Green-stop, field backlight module 10 is set on a liquid crystal display, light source 13 emits The light from the left reaches the other side of the light guide plate in a scattering manner, so that the light guide and the light guide have uniform brightness. However, as the size of the liquid crystal display becomes more and more, the size of the light guide plate 11 also becomes smaller. Relatively increased. At this time, if the light from the light source 1 3 is shot from the straight side of the large-sized light guide plate into the end-illumination side, the imported light will be because the size of the light guide plate is too large (light Row

^ Road II is too long) and cannot smoothly reach the other upright side of the light guide plate. Therefore, the light guide plate 1 1 will have a brightness difference between the side near the light source 1 3 and the other side far from the light source 13, so that the liquid crystal display cannot show uniform brightness.

Referring to FIG. 2 ', the drawing is a partial cross-sectional view of a conventional direct type backlight module. In the second figure, the backlight module 20 includes at least a light guide diffusion plate 21, a reflective sheet 22, a light source 23, a multilayer optical film 24, and a frame 25. The light-guiding diffuser plate 21 also has the function of guiding light, but its main function is to evenly diffuse light. The light guide diffusion plate 21 has a light emitting surface 21a and a lower surface 21b, and the light source 23 is disposed below the lower surface gib of the light guide diffusion plate 21. The reflection sheet 22 is disposed under the light source 23 and reflects the light back to the light guide diffusion plate 21. The multilayer optical film 24 is disposed on the light-emitting surface 21a of the light guide diffusion plate 21, and is generally composed of a diffusion sheet and a cymbal sheet, and the frame 25 is used to fix the above-mentioned elements. Because the backlight module 2 0 疋 evenly distributes several light sources of the light source 2 3 between the light guide diffusion plate 21 and the reflection sheet 22 ′ In theory, the light should be uniform

200424694 V. Description of the invention (3) Direct-type backlight module 20 distributed throughout the display. However, since the thickness of the light guide _ diffuser plate 21 is usually only 2 to 4 mm (mm), the light guide path provided by the light guide diffuser plate 21 is very short when light travels inside the light guide diffuser plate 21. Part of the light is difficult to diffuse evenly, resulting in strong scattered light in some areas of the light guide diffusion plate 21, but no light is emitted in some areas. As a result, the uniformity of the backlight module 20 is deteriorated, which causes a significant difference in brightness between the liquid crystal display and the visual effect of the liquid crystal display. Therefore, for the backlight module 20, it is necessary to further use the diffusion sheet in the multilayer optical film 24 to diffuse the light emitted from the light guide diffusion plate 21, so that the backlight module 20 can obtain a more uniform light. Turn out. However, since the light-shielding rate of the light guide diffusion plate 21 and the multilayer optical film 24 is relatively high, the brightness of the backlight module 20 is greatly affected. ”In view of this, for the practitioners who manufacture LCD monitors, Mo- is not committed to the improvement of backlight modules, in order to be able to propose a better solution to the disadvantages of the traditional backlight & group, and then design a A backlight module with high brightness and better uniformity to improve the vision of the LCD monitor. '[Summary of the Invention] There is iron here, and the purpose of the present invention is to provide _ a kind of light-increasing and diffusing film that can be applied to a back-light module, so that the light guide plate in the backlight module has light diffusion, light enhancement and The advantage of high light uniformity, by applying this & diffusion film, can reduce the use of diffusion sheets and cymbals in traditional multilayer optical films' and improve the brightness quality of backlight modules. According to the purpose of the present invention, a light enhancement applied to a backlight module is proposed.

200424694 V. Description of the invention (4), loose film. The composition of the light-increasing diffusion film includes at least one plastic (p0 1 ye thy 1 ene tereph tha 1 ate, PET) plastic, a conjugated double bond, a planar structure, and at least one Electron donation / earthen / not white moon 丨 and monomethyl stone oil brightener. The thickness of the light-increasing diffusion film ranges from about 0.05 mm to 0.6 mm, and is disposed on the light-emitting surface of the light guide plate by electrostatic adhesion or by attaching a backing adhesive, or 1 ^ can pass through this After the diffusion and enhancement effect of the light-increasing diffusion film, it becomes the light with the uniformity of the south. According to another object of the present invention, a backlight module is provided, which includes an I 4 ′ light plate, a reflection sheet, and a light-increasing diffusion film. This brightening Ϊ = ΐ component includes a PET plastic, a photobleaching agent with a common double bond, an oil St, and an electron donor base, and -methyl lithium 0 ^ \ The thickness range of this brightening diffusion film is about In order to achieve the configuration, Λ'Λ Jing by static " inching mode or # by attaching a square film, on the other hand, on the light emitting surface, the light can pass through the light-increasing thinning and light-increasing effect to become high uniformity. Degrees of light. Understand, the above-mentioned purpose, characteristics, and advantages can be more obvious. It is easy to clarify as follows. A preferred embodiment is given below and described in detail with the attached drawings. [Embodiment] The spirit of optical expansion is to propose a backlight module that can be applied to backlight modules. When Zhongzhi Zeng's upper gastric line passes through the light-increasing diffusion film, it will pass through the light-increasing diffusion film.

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TW1112F (BenQ) .ptd 200424694 V. Description of the invention (5) The film diffuses and enhances the light, and becomes a high uniformity light. By using this light-increasing diffusion film, it is possible to reduce the use of diffusion sheets and cymbals in conventional multi-layer optical films and improve the brightness quality of backlight modules.

Please refer to FIG. 3, which shows a partial cross-sectional view of a light-increasing diffusion film applied to a side-type backlight module according to a preferred embodiment of the present invention. In FIG. 3, the lateral backlight module 30 includes at least a light guide plate 31, a reflection sheet 32, a light source 33, and a light-increasing diffusion film 39. The light guide plate n has a light emitting surface 31 a, a lower surface 31 b, and an upright side 3 1 c. The upright side 31 c is connected to the light emitting surface 31a and the lower surface 31b, and the light guide plate 31 is used to guide the received light to exit through the light emitting surface 3 1 a. The light source 3 3 is disposed outside the upright side 3 1 c to provide light, and the light provided by the light source 33 will enter the light guide plate 31 from the upright side 3 1 c. The light source 13 may be a cold cathode fluorescent lamp (CCFL) or a lamp tube. reflection

The sheet 32 is disposed below the lower surface 31b, and is configured to reflect light to the inside of the light guide plate 31. The light-increasing diffusion film 39 is disposed on the light-emitting surface 31 ^ of the light guide plate 31 by an electrostatic adhesion method or by attaching a backing adhesive. When the light emitted from the light-emitting surface 3 1 a passes through the light-increasing diffusion film 39, it can pass through the diffusion and light-increasing effect of the light-increasing diffusion film 39 to become light with high uniformity. The components of the light-enhancing diffusion film 39 include at least one polyethylene terephtha late (PET) plastic, a photobleaching agent, and a light-enhancing agent. The light-increasing diffusion film 39 has a thickness ranging from about 0.5 mm to 0.6 mm, and is obtained by mixing the photobleach and the brightener into PET plastic and then heating and molding. The chemical structure of this photobleach has a conjugated double bond and is a planar structure, and has an electron donor. this

TW1112F (BenQ) .ptd Page 10 200424694 V. Description of the invention (6) The brightener is a monomethyl silicone oil and its basic chemical formula is as follows: ch3 ch3 ch3 ch3 CH3 —Si —〇— Si —Si —〇— Si- CH3 1111 ch3 ch3 ch3 ch3 The viscosity range of this brightener is about 9 ~ 11 ± 2 mmVs, the refractive index at 25 t is about 1.350 ~ 1.5 00%, and the specific gravity at 25 t is about 0.90 ~ 0.96. #In addition to the light-increasing and diffusing film disclosed in the present invention, in addition to being applied to a side-type backlight unit (as shown in FIG. 3), the light-increasing and diffusing film of the present invention can also be applied to a direct type backlight module. The light source in the direct type backlight module is arranged between the light guide plate and the reflection sheet, so that the light provided by several light sources can be evenly distributed between the light guide plate and the reflection sheet. The light-increasing and diffusing film is arranged on the light-emitting surface of the light guide plate, and when light passes through the light-increasing and diffusing film, the light that passes through the light-increasing and diffusing film diffuses and enhances the light, and becomes light with high uniformity. The light-increasing diffusion film disclosed in the above embodiments of the present invention can be applied to a backlight module for providing a light source in a display panel. The design of forming a light-increasing diffusion film on the light-emitting surface of the light guide plate in the backlight module has at least the following advantages: First, to improve the f: f difference problem of the side-type backlight module in large-sized liquid crystal displays, so that the light guide plate has Brightening effect, improve backlight M, group

TW1112F (BenQ) .ptd Page 11 200424694 V. Description of the invention (7) Brightness quality. 2. Improving the uneven light of the direct-type backlight module in large-sized LCDs, so that the uniformity becomes worse, causing a significant difference in brightness and darkness on the LCD, which makes the light guide plate have light diffusion, brightness enhancement and high light uniformity. Degree and other characteristics. 3. Reduce the use of diffusers and cymbals in traditional multilayer optical films, while reducing manufacturing costs. In summary, although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make various changes without departing from the spirit and scope of the present invention. And retouching, so the scope of protection of the present invention shall be determined by the scope of the appended patent application.

TW1112F (BenQ) .ptd Page 12 200424694 Brief description of the drawings [Simplified description of the drawings] Figure 1 shows a partial cross-sectional view of a conventional side-type backlight module. FIG. 2 is a partial cross-sectional view of a conventional direct type backlight module. FIG. 3 is a partial cross-sectional view of a light-increasing diffusion film applied to a side-type backlight module according to a preferred embodiment of the present invention. Description of the reference numerals 10, 2 0, and 3 0: the lower side of the light emitting surface of the backlight module is an upright side 11, 31: the light guide plate 21: the light guide diffusion plate 11a, 21a, 31a lib, 21b, 31b 11c, 21c, 31c 12, 22, 32: reflectors 13, 23, 33: light source

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Claims (1)

200424694 6. Scope of patent application 1. A light-enhancing diffusion film, comprising: a polyethylene terephthalate (PET) plastic; a photobleaching agent; the photobleaching agent has a conjugated double bond and is flat Structure, and has at least one electron donor base; and a fluorene-based silicone oil-based brightener. 2 · The light-increasing diffusion film as described in item 1 of the scope of patent application, wherein the chemical formula of the light-enhancing agent is: ch3 ch3 ch3 ch3 CH3 — Si — 0 — Si — Si — 〇Si — CH3 ch3 ch3 ch3 ch3 o 3. For example, the light-increasing diffusion film described in item 1 of the scope of patent application, the light-increasing diffusion film is obtained by mixing the light-enhancing agent and the photobleaching agent into the PET plastic, and then heating and forming. 4. The light-increasing diffusion film according to item 1 of the scope of the patent application, wherein the thickness of the light-increasing diffusion film is in the range of about 0.05 mm to 0.6 mm. 5. The light-increasing diffusion film according to item 1 of the scope of the patent application, wherein the viscosity range of the methyl stone oil-based light-enhancing agent is about 9 to 11 ± 2 mm2 / s. 6. The light-increasing diffusion film according to item 1 of the scope of application for a patent, wherein the refractive index of the fluorene-based silicone oil-based lightening agent at 25 ° C is about 1.350 ~ 1.5 0 0%. TW1112F (BenQ) .ptd Page 14 200424694 VI. Application for patent scope 7 · The light-increasing diffusion film described in item 1 of the scope of patent application, wherein the specific gravity of the methyl silicone oil-based brightener is about 0 at 2 5 t · 90 ~ 0 · 96, 8 · The light-increasing diffusion film according to item 1 of the patent application scope, wherein the light-increasing diffusion film is configured to be disposed on a light emitting surface of a light guide plate of a backlight module. 9. A backlight module comprising: a light source for providing a light; a light guide plate 'having a light emitting surface, a lower surface and an upright side'; the upright side is connected to the light emitting surface and the lower surface, the light guide plate For guiding the light provided by the light source to exit through the light emitting surface; a reflecting sheet is disposed under the light guide plate to reflect the light back to the light guide plate; and a light-increasing diffusion film is disposed in the On the light-emitting surface of the light guide plate, the light from the light source is diffused and enhanced by the light-increasing diffusion film to become light with high uniformity. The light-increasing diffusion film further includes: a polyethylene terephthalate Polyethylene terephthalate (PET) plastic; a photobleach, the chemical structure of the photobleach has a common 轾 m double bond and is a flat structure, and has at least one electron donor; and a fluorene-based silicone oil-based brightener . 10. The backlight module according to item 9 in the scope of the patent application, wherein the backlight module is a side-type backlight module, and the light source is arranged beside the upright side so that the light provided by the light source is upright Side into the light guide TW1112F (BenQ) .ptd Page 15 200424694 6. In the scope of patent application 〇11. The backlight module as described in item 9 of the scope of patent application, wherein the backlight module is a direct type backlight module, the light source is configured Between the light guide plate and the reflection sheet, the light provided by the light source can be evenly distributed between the light guide plate and the reflection sheet. 12. The backlight module according to item 9 of the scope of patent application, wherein the chemical formula of the brightener in the light-increasing diffusion film is: ch3 ch3 ch3 ch3 CH3 — Si — 〇1Si-Si — 〇1Si — CH3 i ch3 ch3 ch3 ch3 o 13. The backlight module described in item 9 of the scope of patent application, wherein the light-increasing diffusion film is obtained by mixing the light-enhancing agent and the photobleaching agent into the PET plastic and then heating and forming. 14. The backlight module described in item 9 of the scope of patent application, wherein the thickness range of the light-increasing diffusion film is between (K 0 5 mm and 0.6 mm). 15. As described in item 9 of the scope of patent application In the backlight module, the viscosity of the light-enhancing agent in the light-increasing and diffusing film ranges from about 9 to 11 2 mm 2 / s ° 16. The light-enhancing and diffusing film according to item 9 of the patent application scope, wherein the light-enhancing and diffusing film The refractive index of this brightener at 25 ° C is about 1.350 ~ 1.500%. TW1112F (BenQ) .ptd Page 16 200424694 VI. Application for patent scope 17. The light-increasing diffusion film described in item 9 of the scope of patent application, wherein the specific gravity of the light-enhancing agent in the light-increasing diffusion film is about 25 ° C. 0.90 to 0.96 〇 18. The backlight module according to item 9 of the scope of the patent application, wherein the light-increasing diffusion film is electrostatically attached to the light-emitting surface of the light guide plate. 19. The backlight module according to item 9 of the scope of patent application, wherein the light-increasing diffusion film is disposed on the light-emitting surface of the light guide plate by attaching a backing. TW1112F (BenQ) .ptd Page 17