TW583442B - Polarized light source device and back light module for liquid crystal display - Google Patents

Abstract

A polarized light source comprises an illuminant, a reflective film and a plurality of metal grid wires. The illuminant is used for generating light. The reflective film surrounds the illuminant and has an opening for emitting the light. The metal grid wires is disposed at the opening for transmitting the light with a predetermined polarization therethrough.

Description

583442 __m-JJJ-25380__Month of the month correction V. Description of the invention (1) [Field of the invention] The present invention relates to a light source device for providing polarized light, and more particularly to a polarizer for a liquid crystal display. Chemical light source device. [Prior Art] As shown in Fig. 1, the structure of a conventional liquid crystal display (LCD) device is displayed. Generally speaking, the liquid crystal display device includes a liquid crystal display panel 10 'which includes a liquid crystal material disposed between two substrates, a backlight module 20 disposed below the liquid crystal panel 10, and housings 11 and 12. The backlight module 20 is configured to evenly distribute the light emitted by a light source onto the surface of the liquid crystal panel 100. The backlight module 20 for liquid crystal displays can be generally classified into a direct light source type and a side light source type. Please refer to FIG. 2, which shows a direct type backlight module 2 丨, which is a cross-sectional view taken along the section line 2-2 in FIG. 1. The direct-type backlight module 2 includes an outer casing 70, which has a reflective sheet 60 disposed on a bottom surface thereof, and a lamp tube 50 such as a cold cathode tube, which is located inside, and a diffuser sheet 40 located at the The case 70 and the cymbal sheet 30 are arranged on the diffusion sheet 40. Please refer to FIG. 3, which shows a side-type backlight module 2 2 which is a cross-sectional view taken along the section line 2-2 in FIG. 1. The side-type backlight module 22 includes a light guide plate 80, a lamp tube 50 attached to at least one side of the light guide plate 80, and a U-shaped reflector 61 surrounding the lamp tube 50. An opening portion of the reflector 61 is fixed to the side of the light guide plate 80, a reflection sheet 60 is fixed to the bottom of the light guide plate 80, a diffusion sheet 40 is fixed to the light guide plate 80, and an edge The lens 30 is fixed to the diffusion plate 40. The light guide plate 80 has a printed dot-shaped or v-shaped groove pattern 82 located on at least one surface of the light guide plate 80 to scatter the light in the light guide plate 80 and the case number is 583442 --- case number 91125380 _ Year, month, and day correction_ V. Description of the invention (2) Illuminate the LCD panel 10, and it is generally formed by the pMMA rolling method or the injection method. The diffusion sheet 40 is disposed on the light guide plate 80, and is generally made of translucent PET, polycarbonate (PC), or polyethylene terephthalate plastic (PET). The light emitted from the light guide plate is more uniform. The diaphragm 30 is arranged on the diffuser 40, and is used to collect the light emitted by the diffuser 40 in a direction perpendicular to the diaphragm 30. In summary, 'Because the LCD panel has a polarizing plate to guide the light in a specific polarization direction into the LCD panel and absorb the light in the other polarization direction, the light will lose about 5 when passing through the polarizing plate. 〇% optical energy. Therefore, a polarization recycling film 35 is typically disposed on the cymbal 30 to reflect the light in the other polarization direction, and the polarization is changed by the reflection of the optical element below. Orientation is reused to improve the brightness of the LCD. However, 'the polarized circulation film described above is usually purchased from 3MTM Company of Minnesota, USA under the trade name Dual Brightness Enhancement Film (DBEF)' and can relatively increase the brightness of the LCD monitor to about 1600-170%, but The polarizing recycling film system is quite expensive, and the manufacturing cost will increase significantly with the increasing size of liquid crystal panels. U.S. Patent No. 5,477,422 issued to Hooker et al. On the 19th, and

Generally, the backlight module of Lu 'LCD must meet the requirements of high energy efficiency, increasing screen brightness, providing uniform illumination, reducing power consumption, reducing manufacturing costs, and reducing volume. Many efforts have been made in the prior art to try to meet the aforementioned requirements, such as, for example, U.S. Patent No. 6,164,790, issued to Lee on December 26, 2000, 1995 Dec. 583442 Case No. 91125380 Λ_B means Amendment V. Description of the Invention (3) US Patent No. 5,485, 354 issued to Ciupke et al. On January 16, 1996. U.S. Patent No. 6,122,103 issued to Perkins et al. On September 19, 2000, entitled Broadband Wire Grid Polarizer For The π for the Visible Light Spectrum Visible Spectrum) ", incorporated herein by reference, discloses a polarizer with a metal grid that provides high transmission and reflection efficiency throughout the visible light spectrum. Patent No. 1 1 (1 999) -233 9 1 9 No., which is incorporated herein by reference, discloses a fluorescent tube with a reflective film, which is used in a backlight module of a liquid crystal display to reduce the brightness generated by the interaction by avoiding interaction between adjacent lamps. However, the light source or backlight module provided by the aforementioned patent and the prior art still cannot meet the above requirements for the backlight module. In view of this, it is necessary to provide a light source and / or backlight module for liquid crystal In the display, the aforementioned disadvantages can be overcome. [Summary of the Invention] An object of the present invention is to provide a light source for generating polarized light to illuminate a liquid crystal display surface. Panel, thereby improving the energy utilization rate of the liquid crystal display. Another purpose of the present invention is to provide a backlight module for providing polarized light and light to a liquid crystal display panel, thereby increasing the energy of the backlight module. The utilization rate and the illuminance of the liquid crystal display. In order to achieve the above-mentioned object, the present invention provides a polarized light source including at least T 包括, J 二 it #: a light-emitting unit, a reflective film, and a metal grid. The light-emitting unit

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Page 6 583442 _____ Case No. 91125380_ Year Month Amendment _ V. Description of the Invention (4) The element is used to generate light. The reflective film surrounds the light-emitting unit to reflect light, and the reflective film has an opening to allow the light to pass through. The metal grid is arranged at the opening to generate polarized light. According to another aspect of the present invention, the present invention further provides a backlight module for illuminating a liquid crystal display panel of a liquid crystal display. The backlight module includes at least a light source and a plurality of optical films disposed between the light source and the liquid crystal display panel. The light source includes a light emitting unit, a reflective film, and a metal grid. The light emitting unit is used for generating light. A reflective film surrounds the light-emitting unit to reflect light, and the reflective film has an opening through which the light passes. Metal grid lines are arranged at the openings to generate polarized light. Therefore, according to the light source of the present invention, since it has a polarizing element, it can provide polarized light without reducing the energy utilization rate. In addition, this polarized light can directly pass through the polarizing film of the liquid crystal display, thereby reducing the light received by the polarizing film 'and thus increasing the energy utilization rate of the overall liquid crystal display. Therefore, according to the backlight module or the light source of the present invention, it is not necessary to use an expensive optical film to increase the energy utilization rate of the overall liquid crystal display, increase the illumination of the liquid crystal display, and reduce the manufacturing cost of the liquid crystal display. [Please send the light source to the lamp BenQ 00575.ptc]

Reference is made to Fig. 4 'which shows a polarization or lamp tube 150 according to a first embodiment of the present invention. The lamp 50 is used in a liquid crystal display, typically a cold cathode fluorescent tube (CCFL), and has an elongated tubular structure. The lamp tube 15 has a permeability such as a glass tube 152 and a reflective film 154 coated on the broken tube.

Page 7 534442 _Case No. 9125380__Year Month Chromium ___ V. Description of the Invention (5) The inner wall of 152, mercury vapor 158 is filled in the glass tube 152, and a fluorescent material 1 5 6 is disposed in the mercury vapor Between 1 5 8 and the glass tube 1 5 2. When a voltage is applied to both sides of the lamp tube 150, the mercury vapor 15 8 will be excited to cause the fluorescent material 15 6 to generate visible light. The light generated by the fluorescent material 1 5 6 is reflected by the reflective film 1 5 4 and exits through an opening 1 5 3 of the reflective film 1 5 4. As shown in the figure, the angle 0 in the radial direction of the opening 153 is preferably less than 90 degrees, and the optimal range is 30 degrees to 90 degrees. The lamp tube 150 also has a plurality of metal grid lines 190, which are arranged parallel to the longitudinal axis direction of the lamp tube 150 and are located at the openings 5 and 3 of the reflective film 5 4. Please refer to FIG. 6 further, the metal grid line 190 is formed on the inner wall of the glass tube 152 at intervals, so that light polarized in a direction perpendicular to the metal grid line ig0 will exit through the opening 153. The light polarized in a direction parallel to the metal grid line 190 will be reflected. Those skilled in the art will appreciate that the polarized light source device according to the present invention is not limited to a cold cathode ray tube. Other light source devices, such as incandescent lamps such as halogen lamps, or discharge lamps such as xenon lamps and neon iamps, can also be provided with metal grids Line and reflective film as a polarized light source device. The polarized light source device according to the present invention has a light emitting unit such as a filament of an incandescent lamp or a gas of a xenon lamp, a reflective film having an opening for projecting light, and a A metal grid polarizer is disposed at the opening to generate polarized light. Please refer to Fig. 5, which shows a polarized light source or lamp tube i50 according to a second embodiment of the present invention. The lamp tube 150 has a reflective film 154 and is coated

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__ Case No. 9112538q V. Description of the invention (6) It is outside a glass tube 1 5 2 and has an opening 1 5 3 ,. A plurality of metal grid lines 190 'are arranged on the glass tube 5 2 and the outer side is located at the opening 1 5 3. The function of the metal grid line 190 ′ is similar to that of the metal grid line 9o. It is used to pass the light polarizing direction perpendicular to the metal grid line 9o0, and reflects the light polarizing direction parallel to the metal grid line. 190, the light. Please refer to FIG. 6, which shows a metal wire of the lamp tube 150 according to the first embodiment of the present invention. According to the present invention, the metal grid 9o is preferably made of aluminum, silver, copper, or an alloy metal, and the best one is made of Isao. In a better case, the distance p between the metal grid lines and 90 is less than about 300 nm, the thickness τ of the metal grid lines 190 is from about 30 to about 200 nm, and the metal grid The ratio of the width W of the line 丨 9 to the pitch p ranges from about 3.1 to about 0.8. The metal grid line of the present invention can be formed on the glass tube 152 simultaneously with the reflective film 154 by the same process as the reflective film 154. Alternatively, the metal grid lines can also be formed by additional processes. Those skilled in the art can also understand that the direction of the metal grid line can be changed as needed. Please refer to FIG. 7 again, which shows a liquid crystal display 1 Q using a lamp tube according to the first embodiment of the present invention. The liquid crystal display 1 Q 〇 includes a liquid crystal display panel 110 and a backlight module 120. The liquid crystal display panel 1 10 has two transparent substrates 11 2, 1 1 4 and a liquid crystal material 116 arranged therein. The transparent substrate of the liquid crystal display panel 111 is provided with polarizing films 11 8 and 11 9 on the outer surface, and a switching element is provided on the inner surface to change the liquid crystal. The arrangement of molecules produces an image. The backlight module 120 is used as a planar light source, which evenly irradiates the liquid.

Case No. 583442-9/125/380 Amendment V. Description of the invention (7) Crystal display panel 1 1 0. The backlight module 2 includes the lamp tube 150, a U-shaped reflector 161 surrounding the light source 150, a light guide plate 180, which are generally wedge-shaped, and a plurality of optical films, such as a diffuser 14 and a prism. Lenses 1 3 0. The diffuser sheet 140 is used to make the light more uniform. The cymbal 130 is commercially available from 3M? Company under the trade name BEF Π (Brightness

Enhancement Film Π) is used to concentrate light in the vertical direction. The light emitted by the lamp 150 is a polarized aurora perpendicular to the direction of the lamp 丨 5 0 (normal to the metal grid line 190 ), And incident into the incident surface 1 84 of the light guide plate 180. The light guide plate 180 has a diffusing element 1 82, such as a dot pattern or a V-shaped groove pattern, which is located on the lower surface of the light guide plate 180 and is used to direct the light incident into the light guide plate 180. Scattered and emitted from the upper surface or the exit surface 185 of the light guide plate 8o to become a uniform surface light source, and illuminate the liquid crystal display panel 1 10. The light guide plate 180 is generally formed by a ρ μΜ A calendering method or an injection method. The light guide plate 180 further has a reflecting mirror ΐβ5, which is arranged at the end of the light guide plate 180 to reflect the light back to the light guide plate 800. Further, in the light guide plate 180, the polarized light is reflected in the light guide plate 180 by the scattering element 182, and is substantially perpendicular to the lamp tube 150 (perpendicular to the metal grid line 190). The polarized direction is incident into the liquid crystal display panel 110, thereby reducing the light absorbed by the polarizing film 119 of the liquid crystal display panel 丨 i0, and improving the light utilization ratio of the liquid crystal display 丨 00. Those skilled in the art will understand that the polarizing direction of the polarizing film 119 on the liquid crystal display panel 丨 丨 should correspond to the polarizing direction of the metal grid 19, so that the liquid crystal display 1 can be improved. The illumination. In general

00575.ptc Page 10 583442 Case No. 91125380 V. Description of the invention (8) It is said that because of the configuration of the liquid crystal display, the backlight module 1 2 of the present invention will be particularly suitable for lateral electric field effect (In-Plane-Switching) , Vertical Alignment, and Multi-Domain Vertical Alignment (Thin Film)

Transi stor) LCD panel. Please refer to FIG. 8, which discloses another liquid crystal display 2000 using the lamp tube according to the first embodiment of the present invention. The liquid crystal display 200 is substantially similar to the liquid crystal display 100, wherein similar elements are marked with similar figures. The liquid crystal display state 200 has a direct-type backlight module 220, which has a plurality of lamp tubes 150 (four lamp tubes are shown in the figure) arranged in a casing wo. The polarized light emitted by the lamp officer 150 can be directed toward the liquid crystal display panel through the diffusion sheet 24o and the prism sheet 230 '. The polarized light can pass through the polarizing film 219 of the liquid crystal display panel 21 to minimize the light absorbed by the polarizing film 219, thereby improving the utilization ratio of the liquid crystal display light. m ;; The light source of the present invention can directly provide polarized lines that can pass directly through the liquid crystal display. The polarized light source does not need to be expensive. Therefore, the energy utilization ratio of the display according to the present invention can further improve the overall liquid crystal display. Manufacturing cost of crystal display. Although the present invention has been formulated with the aforementioned preferred implementation, anyone who is familiar with this technique will not be able to use it. "Otherwise, the range of Asia and Africa is within the limits, and it can be changed in various ways. The spirit of the present invention and the scope of patent application attached ^ deciding = protection scope of the present invention 00575.ptc 583442 case number 91125380 month and month amend the diagram simple illustration [illustration] In order to make the above and Other objects, features, and advantages can be more obvious. The preferred embodiments of the present invention will be described below in detail with the accompanying drawings as follows. FIG. 1 is a three-dimensional perspective development view of a liquid crystal display according to the prior art. FIG. 2 is a schematic cross-sectional view of the direct-type backlight module according to the prior art, taken along the line 2-2 of FIG. 1. FIG. 3 is a schematic cross-sectional view of the side-type backlight module according to the prior art, taken along the line 2-2 of FIG. 1. Fig. 4 is a schematic sectional view of a lamp tube according to a first embodiment of the present invention. Fig. 5 is a schematic sectional view of a lamp tube according to a second embodiment of the present invention. Fig. 6 is an enlarged perspective view of a portion of a metal grid of a light source according to an embodiment of the present invention. Fig. 7 is a schematic cross-sectional view of a liquid crystal display using a lamp tube according to a first embodiment of the present invention. Fig. 8 is a schematic cross-sectional view of another liquid crystal display using a lamp according to the first embodiment of the present invention. Drawing number description: 11 housing 21 direct-lit backlight module 10 LCD display β panel 20 backlight module 12 housing

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Case No. 91125380_Year Month and Day Revised Schematic Description 70 Housing 60 Reflective Film 50 Light Tube 40 Diffusion Film 30 Cymbal 55 Support Pillar 22 Side Backlight Module 80 Light Guide Plate 61 U-shaped Reflector 82 Pattern 100 LCD Monitor 110 LCD display panel 112 Transparent substrate 116 Liquid crystal material 114 Transparent substrate 118 Polarizing film 119 Polarizing film 120 Backlight module 130 Diaphragm 140 Diffuser 150 Light tube 150, Light tube 152 Glass tube 152, Glass tube 153 Open σ 153, Opening 154 Reflective film 154, Reflective film 156 Fluorescent material 158 Mercury vapor 161 U-shaped reflector 165 Mirror 180 Light guide plate 182 Diffuser 184 Incident surface 185 Emission surface 190 Metal grid line 190, Metal grid line 200 Liquid crystal display 210 Liquid crystal display panel 212 Transparent substrate 214 Transparent substrate 219 Polarizing film 220 Backlight module 230 Diaphragm 240 Diffuser 2 70 Housing 00575.ptc Page 13

Claims (1)

5 8: ----- A year Λ correction replaces multiple h, if. A polarized light source includes: a light emitting unit for generating light; a reflective film surrounding the light emitting unit for reflecting light, wherein the reflective film has a An opening to allow the light to pass through; and a plurality of metal grid lines arranged at the opening to generate polarized light. ^ The polarized light source according to item 1 of the patent application, wherein the metal grid is made of aluminum. The polarized light source of item 1 in the long-sought% patent scope, in which the material for manufacturing the metal t is in the group consisting of aluminum, silver, steel, and their alloys A polarized light source, wherein the metal grid line < the 2 giant system is not larger than 300 nm. 5. The polarized light source according to item 丨 in the scope of the patent application, wherein the drought degree of the metal grid line is not less than 30 nm and not more than 200 nm. 6. The polarized light source according to item 1 of the scope of the patent application, wherein the ratio of the width of the metal grid line to the pitch is not less than 0 · 1 and not more than 0 · 8. 7 · The polarized light source according to item 1 of the patent application, wherein the light-emitting unit Page 14 534442 Case No. 9112¾ --- Feng a-day——J ^ · --- 6. The scope of patent application includes a transparent tube, mercury vapor filled in the transparent tube, and a fluorescent material coated on the transparent On the tube, and the reflective film and the metal grid are arranged on the transparent tube. 8. The polarized light source according to item 7 of the scope of the patent application, wherein the reflective film and the metal grid are arranged inside the transparent tube, between the light-emitting material and the transparent tube. 9 The polarized light source according to item 7 of the scope of the patent application, wherein the reflective film and the metal grid are arranged outside the transparent tube. 10. The light source according to item 7 of the scope of patent application, wherein the transparent tube is an elongated circular tube, and the opening of the reflective film extends along the axial direction of the transparent tube and is at an angle in the radial direction thereof. Department is less than 90 degrees. 11 According to the light source of item 7 of the scope of the patent application, wherein the transparent tube is a substantially elongated circular tube, and the opening of the reflective film extends in the axial direction of the transparent tube, and The angle is 30 degrees to 90 degrees. 1 2. The polarized light source according to item 1 of the patent application scope further includes a transparent substrate, wherein the reflective film and the metal grid are formed on the transparent substrate by the same process. 1 3. —A backlight module for a liquid crystal display to illuminate a liquid crystal display 00575.ptc Page 15 583442 Amendment MM 91125380 6. The LCD panel of the patent-applicable indicator includes: a light source, including; a light-emitting unit to generate light; a reflective film, which surrounds the light-emitting unit, is used To reflect light, wherein the reflective film has an opening through which the light passes; and a plurality of metal grid lines are arranged at the opening to generate polarized light; a light guide plate is located on the liquid crystal display panel Below, there is at least one incident surface facing the light source, a plurality of scattering elements, and an exit surface. The polarized light emitted by the light source enters the light guide plate from the incident surface, and then passes through the scattering. The element scatters the incident light and exits it; and a plurality of optical films are arranged between the light guide and the display panel. The light emitting surface of the u plate and the liquid crystal mirror mirror the backlight module according to item 13 of the second patent ... including an anti-metal grid line 15. According to the backlight module of item 13 of the patent application scope, Made of aluminum. Batucheng 1 6. According to the 13th item in the scope of the patent application, the back and forth yueyouyou formation, the pelt stimulus #person π grid line material is selected from aluminum, silver, copper, /, w ahai metal. Milk and its alloys 00575.ptc Page 16 583442 _ Ά 91125380_ Year ~ ^ 6th, the scope of patent application " " " '' 一 " · 17. According to the backlight module No. 13 of the scope of patent application, The distance between the metal grid lines is not more than 300 nm. 18. The backlight module according to item 13 of the scope of patent application, wherein the thickness of the metal grid is between not less than 30 and not more than 200 nm. 19. The backlight module according to item 13 of the scope of patent application, wherein the ratio of the width of the metal grid line to the pitch is not less than 0, 1 and not more than 0 · 8. 20 · The backlight module according to item 13 of the patent application scope, wherein the plurality of optical film sheets include: at least one diffusion sheet for dispersing light emitted from the light guide plate; and at least one prism sheet for making light Focus on the vertical direction. 21 · —A backlight module for a liquid crystal display, which is used to illuminate a liquid crystal display panel of a liquid crystal display, including at least one light source, including; a light emitting unit is located below the liquid crystal display panel to generate light; A reflective film surrounds the light-emitting unit and is used to reflect light, wherein the reflective film has an opening through which the light passes; and a plurality of metal grid lines are arranged at the opening to generate polarized light. Light 583442 _Case No. 91125380_Year Month Amendment ___ 6. Scope of Patent Application A plurality of optical films are arranged between the light source and the LCD panel. 2 2. The backlight module according to item 21 of the patent application scope further includes a reflector surrounding the light source. 2 3. The backlight module according to item 21 of the scope of patent application, wherein the metal grid is made by Ming. 2 4. The backlight module according to item 21 of the scope of patent application, in which the material for manufacturing the metal grid is selected from the group consisting of aluminum, silver, copper, and their alloys. 25. The backlight module according to item 21 of the scope of patent application, wherein the distance between the metal grid lines is not greater than 300 nm. 2 6. The backlight module according to item 21 of the scope of patent application, wherein the thickness of the metal grid is between not less than 30 and not more than 200 nm. 2 7. The backlight module according to item 21 of the scope of patent application, wherein the ratio of the width of the metal grid line to the pitch is not less than 0.1 and not more than 0.8. 2 8. The backlight module according to item 21 of the patent application scope, wherein the plurality of optical films include: 00575.ptc Page 18 583442 00575.ptc Page 19