OPTICAL SHEET, SURFACE LIGHT SOURCE DEVICE AND DISPLAY DEVICE

• Main Authors: INOUE ISAO, HAYASHIDA YASUNORI, KITANO KEIKO
• Format: Patent
• Language: English; Japanese
• Published: 26.05.2016
• Subjects: BLASTING; DEVICES OR ARRANGEMENTS, THE OPTICAL OPERATION OF WHICH ISMODIFIED BY CHANGING THE OPTICAL PROPERTIES OF THE MEDIUM OF THEDEVICES OR ARRANGEMENTS FOR THE CONTROL OF THE INTENSITY,COLOUR, PHASE, POLARISATION OR DIRECTION OF LIGHT, e.g.SWITCHING, GATING, MODULATING OR DEMODULATING; FREQUENCY-CHANGING; FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMSTHEREOF; HEATING; LIGHTING; MECHANICAL ENGINEERING; NON-LINEAR OPTICS; NON-PORTABLE LIGHTING DEVICES; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PHYSICS; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHERARTICLES, NOT OTHERWISE PROVIDED FOR; SYSTEMS THEREOF; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLEEXTERIORS; WEAPONS

PROBLEM TO BE SOLVED: To provide an optical sheet that can suppress generation of bright line irregularity on a surface where incident light to the sheet exits.SOLUTION: An optical sheet 60 includes a main body portion 65 and a plurality of unit prisms 70. Each unit prism includes a first prism plane 71 facing one side in a first direction and a second prism plane 72 facing the other side of the first direction. The second prism plane includes a plurality of element planes 73 arranged in such a manner that an inclination angle φ with respect to the first direction on a main cross-sectional plane gradually increases from a top end 75a side of the unit prism to a base end 75b. On the main cross-sectional plane, a maximum distance d between the second prism plane and a virtual line X connecting the top end and the base end, and a width w of the unit prism along an arrangement direction dsatisfy a relationship of 0.4%≤d/W≤5.0%, and a value of d/W relating to each unit prism is different from a value of d/W relating to at least one of other unit prisms.SELECTED DRAWING: Figure 9 【課題】入射した光が出光する面に輝線状のムラが発生することを抑制し得る光学シートを提供する。【解決手段】光学シート６０は、本体部６５と、複数の単位プリズム７０と、を含む。各単位プリズムは、第１方向の一側を向く第１プリズム面７１と、第１方向の他側を向く第２プリズム面７２と、を含む。第２プリズム面は、主切断面において第１方向に対する傾斜角度φが、単位プリズムの先端部７５ａの側から基端部７５ｂの側へ向けてしだいに大きくなるように配置された複数の要素面７３を含む。主切断面において、先端部と基端部とを結ぶ仮想直線Ｘと、第２プリズム面と、の最大距離をｄとし、単位プリズムの配列方向ｄ１に沿った幅をｗとしたときに、０．４％≦ｄ／Ｗ≦５．０％の関係を満たし、各単位プリズムに関するｄ／Ｗの値は、少なくとも１つの他の単位プリズムに関するｄ／Ｗの値と異なる。【選択図】図９