.1378275 1101年 六、發明說明： 【發明所屬之技術領域】 [0001] 本發明涉及一種偏光片之製造方法。 [先前技術3 [0002] 近年來，由於液晶顯示裝置具輕、薄、耗電小等優點， 所以被廣泛應用於筆記本電腦、行動電話、個人數位助 理等現代化資訊設備。由於液晶顯示裝置係一種被動元 件，其本身並不能發光’因而需利用一光源系統作爲液 晶顯示裝置之光源，如背光系統。常見之背光系統包括 導光板與光源。自背光隼統出射之光線進入液晶單元時 必須爲偏振光，因而於液晶單元兩側貼上偏光片以整合 液晶之偏振態。 [0003] 先前偏光片有吸收式偏光片與反射式偏光片。吸收式偏 光片一般爲碘系偏光片或染料系偏光片。由於背光系統 出射之光線爲自然光’任意自然光均可認爲係任意兩偏 振方向相互垂直之線偏振光相互結合作用之結果，即可 將任意自然光拆解爲任意兩個偏振方向相互垂直之線偏 振光，則背光系統出射之任意光線均可認爲係偏振方向 平行於偏光片光軸方向之線偏振光與偏振方向垂直於偏 光片光軸方向之線偏振光相互作用之結果。故，背光系 統出射之光線進入偏光片後，偏振方向平行於’偏光片光 軸方向之線偏振光藉由偏光片直接出射，而偏振方向垂 直於偏光片光軸方向之線偏振光被偏光片吸收，造成光 線浪費。由上述可知，該種偏光片最大光透過率理論上 爲5 0%，實際上僅能達到40%多，光利用率較低。而且製 09414744# 單編號 Α0101 第3頁/共11頁 1013145928-0 1378275 _ 101年04月18日修正替換頁 造上述偏光片，需藉由染色、延伸、貼合、乾燥等多個 步驟，其製程複雜。 [0004] 先前之反射式偏光片之作用係使偏振方向平行於偏光片 光軸方向之線偏振光藉由偏光片直接出射，而將偏振方 向垂直於偏光片光軸方向之線偏振光反射，反射光藉由 兩個1/4波片或一個1/2波片後相位延遲1/2個波長，因 而偏振方向垂直於偏光片光軸方向之線偏振光相位延遲 1/2個波長後變成偏振方向平行於偏光片光軸方向之線偏 振光，再經過偏光片出射〇這種偏光裝置光最大透過率 理論上可達到100%，實際上一般爲70%左右。惟，利用此 種偏光裝置其結構較爲複雜，需要增加兩個1/4波片或一 個1/2個波片與一反射膜，成本也比較高。 【發明内容】 [0005] 有鑒於此，有必要提供一種透光率高及製造成本低之偏 光片之製造方法。 [0006] 一種偏光片之製造方法，其包括以下步驟： [0007] (1)提供一片由具有光學各向異性性質材料製成之透光 基板； [0008] (2)於該透光基板之至少一個表面上形成多個凹槽，以 使自然光入射至該具多個凹槽之表面後，可變成單一偏 振態之線偏振光從該透光基板另一個與該具多個凹槽之 表面相對之表面出射，其中，該凹槽爲橢圓形凹槽，該 多個橢圓形凹槽之長軸方向係沿同一方向，且該方向與 該透光基板表面平行，該凹槽之深度爲2〜100微米，該凹 09414744P編號 A〇101 第4頁/共11頁 1013145928-0 1378275 101年.04月18日梭正替換頁 槽之短軸之尺寸小於入射光之波長，該凹槽之長軸之尺 寸等於或大於入射光之波長，且該凹槽之長軸與短軸之 尺寸比為2~100。 [0009] 相較於先前技術，所述之偏光片之製造方法，藉由於透 光基板一個表面上形成多個凹槽而製成偏光片，其製程 簡單及製造成本低，所得到偏光片之透光率約爲70%並且 能得到單一偏振態之線偏振光。 【實施方式】 [0010] 下面將結合附圖對本發明實施例作進一步之詳細說明。 [0011] 請參閱第一圖，本發明實施例提供之一種偏光片之製造 方法，其包括以下步驟： [0012] 步驟100 :提供一片由具有光學各向異性性質材料製成之 透光基板，該透光基板至少可讓可見光（波長範圍約爲 390〜760奈米）穿透，其厚度為1〜10毫米，較佳爲2〜5毫 米。本實施例中，該透光基板之材料為方解石，方解石 可讓波長範圍爲350〜2300奈米之光穿透。當然，該透光 基板也可選自三氧化二铭（ai2〇3)、二氧化石夕（Si〇2) 或釩酸釔（YVO,)等其他各向異性材料。 4 [0013] 步驟200 :於該透光基板之其令一個表面上形成多個凹槽 。該凹槽爲橢圓形凹槽。該橢圓形凹槽之深度爲2〜100微 米，較佳爲5〜50微米。該橢圓形凹槽之短軸之尺寸小於 入射光之波長，較佳爲入射光波長之一半，該橢圓形凹 槽之長軸之尺寸等於或大於入射光之波長，較佳爲入射 光波長之兩倍且沿該透光基板之表面。該多個橢圓形凹 隱4744#單編號删1 第5頁/共11頁 1013145928-0 1378275 丨 101 年 槽之長轴方向係沿同一方向，且該方向與該透光基板表 面平行。該橢圓形凹槽之長短軸尺寸比爲2〜100，較佳爲 5〜20 °該步驟200可採用雷射加工方法於該透光基板之表 面上形成該多個凹槽。 [0014] 本發明實施例之製造方法進一步包括一個步驟3〇〇 :於該 透光基板具多個凹槽之表面形成一層抗反膜層（ Antireflective coating)。該抗反射膜層至少可讓 可見光（波長範圍約爲390~760奈米）穿透。該抗反射膜 層自凹槽表面向上分別包括四層子膜層：一層二氧化欽 (Ti〇2)層，其厚度為10~16奈米，折射率約爲2. 35左 右；一層二氧化矽（Si09)層，其厚度為26〜32奈米，折 射率約爲1.46左右；一層二氧化鈦（Ti〇2)層’其厚度 為80〜120奈米；一層二氧化矽（si〇2)層’其厚度為 78〜86奈米。該抗反射膜層係利用多重膜間之干涉原理以 減少偏光片對入射光之反射，而達到抗反射之效果。 [0015] 該步驟300可採用真空鍍膜法於該透光基板帶多個凹槽之 表面上形成該透光層。真空鑛膜法可包括電子束蒸鐘法 (Electron-Beam Evaporation)、離子束秦鐘法（.1378275 1101. Description of the Invention: [Technical Field of the Invention] [0001] The present invention relates to a method of manufacturing a polarizer. [Prior Art 3 [0002] In recent years, liquid crystal display devices have been widely used in modern information devices such as notebook computers, mobile phones, and personal digital assistants because of their advantages of being light, thin, and low in power consumption. Since the liquid crystal display device is a passive element, it does not emit light by itself. Therefore, it is necessary to use a light source system as a light source of the liquid crystal display device, such as a backlight system. A common backlight system includes a light guide plate and a light source. The light emitted from the backlight system must be polarized when it enters the liquid crystal cell. Therefore, a polarizer is attached to both sides of the liquid crystal cell to integrate the polarization state of the liquid crystal. [0003] Previous polarizers have an absorptive polarizer and a reflective polarizer. The absorption polarizer is generally an iodine-based polarizer or a dye-based polarizer. Since the light emitted by the backlight system is natural light, any natural light can be considered as a result of the combination of any two linearly polarized lights whose polarization directions are perpendicular to each other, and any natural light can be disassembled into linear polarizations of any two polarization directions perpendicular to each other. In the light, any light emitted from the backlight system can be considered as a result of the interaction of the linearly polarized light whose polarization direction is parallel to the optical axis direction of the polarizer and the linearly polarized light whose polarization direction is perpendicular to the optical axis direction of the polarizer. Therefore, after the light emitted by the backlight system enters the polarizer, the linearly polarized light whose polarization direction is parallel to the direction of the optical axis of the polarizer is directly emitted by the polarizer, and the linearly polarized light whose polarization direction is perpendicular to the optical axis of the polarizer is polarized. Absorbed, causing light to be wasted. As can be seen from the above, the maximum light transmittance of the polarizer is theoretically 50%, and actually only 40% or more, and the light utilization rate is low. Moreover, the system number 9414744# single number Α 0101 3rd page / total 11 pages 1013145928-0 1378275 _ April 18, 2011 correction replacement page to make the above polarizer, through dyeing, stretching, lamination, drying and other steps, The process is complicated. [0004] The former reflective polarizer functions to linearly polarize light having a polarization direction parallel to the optical axis direction of the polarizer, and directly reflect the linearly polarized light having a polarization direction perpendicular to the optical axis direction of the polarizer. The reflected light is phase-delayed by 1/2 wavelength by two quarter-wave plates or a 1/2-wave plate, so that the phase of the linearly polarized light whose polarization direction is perpendicular to the optical axis direction of the polarizer is delayed by 1/2 wavelength. The linearly polarized light whose polarization direction is parallel to the optical axis direction of the polarizer, and then exits through the polarizer. The maximum light transmittance of the polarizing device can theoretically reach 100%, and is generally about 70%. However, the structure of the polarizing device is complicated, and it is necessary to add two quarter-wave plates or one 1/2 wave plate and a reflecting film, and the cost is relatively high. SUMMARY OF THE INVENTION [0005] In view of the above, it is necessary to provide a method of manufacturing a polarizer having high light transmittance and low manufacturing cost. [0006] A method of manufacturing a polarizer, comprising the steps of: [0007] (1) providing a light-transmissive substrate made of a material having optical anisotropy; [0008] (2) Forming a plurality of grooves on at least one surface such that natural light is incident on the surface having the plurality of grooves, and the linearly polarized light that can become a single polarization state is from the other of the transparent substrate and the surface having the plurality of grooves Opposite the surface, wherein the groove is an elliptical groove, the long axis direction of the plurality of elliptical grooves is in the same direction, and the direction is parallel to the surface of the transparent substrate, the depth of the groove is 2 ~100 micron, the concave 09914744P number A〇101 4th page/total 11 pages 1013145928-0 1378275 101. On April 18th, the short axis of the shuttle replacement slot is smaller than the wavelength of the incident light, the length of the groove The size of the axis is equal to or greater than the wavelength of the incident light, and the ratio of the major axis to the minor axis of the groove is 2 to 100. [0009] Compared with the prior art, the method for manufacturing a polarizer is to form a polarizer by forming a plurality of grooves on one surface of the transparent substrate, which is simple in process and low in manufacturing cost, and the obtained polarizer is obtained. The light transmittance is about 70% and linearly polarized light of a single polarization state can be obtained. [Embodiment] [0010] Hereinafter, embodiments of the present invention will be further described in detail with reference to the accompanying drawings. [0011] Please refer to the first figure, a method for manufacturing a polarizer according to an embodiment of the present invention, comprising the following steps: [0012] Step 100: providing a transparent substrate made of a material having optical anisotropy properties, The light-transmitting substrate can penetrate at least visible light (wavelength range of about 390 to 760 nm) and has a thickness of 1 to 10 mm, preferably 2 to 5 mm. In this embodiment, the material of the transparent substrate is calcite, and the calcite can penetrate light having a wavelength in the range of 350 to 2300 nm. Of course, the light-transmitting substrate may also be selected from other anisotropic materials such as alumina (ai2〇3), cerium dioxide (Si〇2) or yttrium vanadate (YVO). [0013] Step 200: forming a plurality of grooves on one surface of the light transmissive substrate. The groove is an elliptical groove. The elliptical groove has a depth of 2 to 100 μm, preferably 5 to 50 μm. The minor axis of the elliptical groove is smaller than the wavelength of the incident light, preferably one half of the wavelength of the incident light, and the major axis of the elliptical groove has a size equal to or greater than the wavelength of the incident light, preferably the wavelength of the incident light. Twice and along the surface of the light transmissive substrate. The plurality of elliptical recesses 4474# single number deletion 1 page 5 / total 11 pages 1013145928-0 1378275 丨 101 years The long axis direction of the groove is in the same direction, and the direction is parallel to the surface of the transparent substrate. The elliptical groove has a length to length ratio of 2 to 100, preferably 5 to 20 °. The step 200 can form the plurality of grooves on the surface of the transparent substrate by a laser processing method. [0014] The manufacturing method of the embodiment of the present invention further includes a step 3: forming an antireflective coating on the surface of the transparent substrate having a plurality of grooves. The antireflective film layer allows at least visible light (wavelength range of about 390 to 760 nm) to penetrate. The anti-reflective film layer comprises four layers of sub-membrane layers from the surface of the groove respectively: a layer of TiO2 layer having a thickness of 10 to 16 nm and a refractive index of about 2.35; a layer of dioxide The layer of bismuth (Si09) has a thickness of 26 to 32 nm and a refractive index of about 1.46; a layer of titanium dioxide (Ti〇2) has a thickness of 80 to 120 nm; a layer of cerium oxide (Si〇2) 'The thickness is 78~86 nm. The anti-reflection film layer utilizes the principle of interference between multiple films to reduce the reflection of the polarizer on the incident light to achieve an anti-reflection effect. [0015] In step 300, the light transmissive layer may be formed on the surface of the transparent substrate with a plurality of grooves by vacuum coating. The vacuum ore film method may include an Electron-Beam Evaporation method and an ion beam Qin clock method (
Ion-Beam Evaporation)、磁控藏锻法（MagnetronIon-Beam Evaporation), magnetron forging method (Magnetron
Sputtering)及電子自旋共振沈積法（Electron Spin Resonance Deposition)等。 [0016] 本發明實施例提供之偏光片之製造方法，藉由於透光基 板一個表面上形成多個凹槽而製成偏光片’其製程簡單 及製造成本低。經上述方法製得之偏光片’其中一個表 面帶有多個橢圓形凹槽。請參閱第二圖，爲本發明液晶 09414744^^^^ A0101 第 6 頁 / 共 11 頁 1013145928-0 •1378275 101年04月18日接正替換頁 顯示裝置10之結構示意圖。該液晶顯示裝置10包括一片 上基板104，一片與上基板104相對設置之下基板108， 一詹液晶層106，該液晶層1〇6設置於上基板1〇4與下基 板108之間’ 一片上偏光片1〇2、一片下偏光片u〇與一 背光模組112。該兩片偏光片102、11〇係採用本發明實 施例提供之製造方法製造，其分別設置於上基板104與下 基板108之外側面。背光模組112發出之自然光可看成兩 個振幅相同且振動方向相互垂直之非相干之線偏振光之 疊加。背光模組112發出之自然光入射至下偏光片no帶 有多個凹槽之表面後，由於下偏光片110具有光學各向異 性’入射光做正交將線偏振光分離出來，從而使偏光片 出射之光爲單一偏振態之線偏振光。而且每片偏光片之 透光率約爲70%，因而該液晶顯示裝置1〇透光率可達到普 通液晶顯示裝置之3倍左右，另外也不需增加光學膜片， 製造成本較低且可使偏光片對入射光之反射率降至1%左 右。 [0017] 綜上所述，本發明確已符合發明專利之要件，爰依法提 出專利申請。惟，以上所述者僅為本發明之較佳實施方 式，本發明之範圍並不以上述實施方式為限，舉凡熟習 本案技藝之人士援依本發明之精神所作之等效修飾或變 化’皆應涵蓋於以下申請專利範圍内。 [0018] 【圖式簡單說明】 第一圖爲本發明實施例提供之一種偏光片之製造方法之 流程圖° ' [0019] 第二圖爲本發明實施例提供之一種偏光片用於液晶顯示 0941474#單編號删1 第7頁/共u頁 1013145928-0 1378275 101年.04月18日按正替換頁 裝置之結構示意圖。 【主要元件符號說明】 [0020] 液晶顯示裝置： [0021] 上基板： 104 [0022] 下基板： 108 [0023] 液晶層. 106 [0024] 上偏光片 ：102 [0025] 下偏光片 :110 [0026] 背光模組 ：112 眶474#單编號A〇101 第8頁/共11頁 1013145928-0Sputtering) and Electron Spin Resonance Deposition. The method for manufacturing a polarizer according to an embodiment of the present invention is characterized in that the polarizer is formed by forming a plurality of grooves on one surface of the light-transmitting substrate, and the manufacturing process is simple and the manufacturing cost is low. One of the polarizers prepared by the above method has a plurality of elliptical grooves. Please refer to the second figure, which is a liquid crystal of the present invention. 09414744^^^^ A0101 Page 6 of 11 1013145928-0 • 1378275 April 18, 2011 Correct replacement page The structure of the display device 10 is shown. The liquid crystal display device 10 includes an upper substrate 104, a substrate 108 disposed opposite the upper substrate 104, and a liquid crystal layer 106 disposed between the upper substrate 1〇4 and the lower substrate 108. The upper polarizer 1 〇 2, a lower polarizer u 〇 and a backlight module 112. The two polarizers 102, 11 are manufactured by the manufacturing method provided by the embodiment of the present invention, and are disposed on the outer sides of the upper substrate 104 and the lower substrate 108, respectively. The natural light emitted by the backlight module 112 can be regarded as a superposition of two incoherent linearly polarized lights of the same amplitude and perpendicular to each other. After the natural light emitted by the backlight module 112 is incident on the surface of the lower polarizer no with a plurality of grooves, since the lower polarizer 110 has optical anisotropy, the incident light is orthogonally separated to separate the linearly polarized light, thereby making the polarizer The emitted light is linearly polarized light of a single polarization state. Moreover, the transmittance of each polarizer is about 70%, so that the transmittance of the liquid crystal display device can be about three times that of an ordinary liquid crystal display device, and the optical film is not required to be added, and the manufacturing cost is low and can be The reflectance of the polarizer to the incident light is reduced to about 1%. [0017] In summary, the present invention has indeed met the requirements of the invention patent, and the patent application is filed according to law. However, the above description is only the preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and those skilled in the art will be able to make equivalent modifications or changes in accordance with the spirit of the present invention. It should be covered by the following patent application. [0018] The first figure is a flow chart of a method for manufacturing a polarizer according to an embodiment of the present invention. [0019] The second figure is a polarizer for liquid crystal display according to an embodiment of the present invention. 0941474#单编号除1 Page 7 / Total u page 1013145928-0 1378275 101. April 18th The structure of the device is replaced by the page. [Main component symbol description] [0020] Liquid crystal display device: [0021] Upper substrate: 104 [0022] Lower substrate: 108 [0023] Liquid crystal layer. 106 [0024] Upper polarizer: 102 [0025] Lower polarizer: 110 [0026] backlight module: 112 眶 474# single number A 〇 101 page 8 / total 11 pages 1013145928-0