OPTICAL SHEET, EDGE LIGHT-TYPE BACKLIGHT UNIT, AND OPTICAL SHEET MANUFACTURING METHOD

• Main Author: NAMIKAWA YOSHITADA
• Format: Patent
• Language: English; Japanese
• Published: 25.02.2016
• 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; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; LIGHTING; MECHANICAL ENGINEERING; NON-LINEAR OPTICS; NON-PORTABLE LIGHTING DEVICES; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PERFORMING OPERATIONS; PHYSICS; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHERARTICLES, NOT OTHERWISE PROVIDED FOR; SYSTEMS THEREOF; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; TRANSPORTING; VEHICLE LIGHTING DEVICES SPECIALLY ADAPTED FOR VEHICLEEXTERIORS; WEAPONS

PROBLEM TO BE SOLVED: To provide an optical sheet capable of preventing damage to another member provided on a rear surface of the optical sheet and/or the optical sheet itself while preventing sticking of the optical sheet to another member.SOLUTION: An optical sheet 2 comprises: a transparent base material layer 6; and a sticking prevention layer 8 laminated on a rear surface of the base material layer 6, the sticking prevention layer 8 including a plurality of fine protrusions 11 formed by nanoimprint and protruding from the rear surface, an inter-vertex distance between the adjacent fine protrusions 11 in a plane direction being equal to or smaller than 380 nm. An average height of the fine protrusions 11 is preferably equal to or larger than 120 nm and equal to or smaller than 380 nm. A ratio of the average height to an average diameter of the fine protrusions 11 is preferably equal to or higher than 1/2 and equal to or lower than 3/2. A curvature radius of the vertexes of the fine protrusions 11 is preferably equal to or larger than 60 nm and equal to or smaller than 1 μm. The sticking prevention layer 8 may contain an antistatic additive.SELECTED DRAWING: Figure 1 【課題】光学シートとこの光学シートの裏面側に配設される他の部材とのスティッキングを防止しつつ、この他の部材及び／又は当該光学シート自体の傷付きを防止できる光学シートを提供する。【解決手段】光学シート２は、透明な基材層６と、この基材層６の裏面側に積層されるスティッキング防止層８とを備え、スティッキング防止層８が、ナノインプリントによって形成され、裏面側に突出される複数の微細突起１１を有し、隣接する微細突起１１の平面方向における頂点間距離が３８０ｎｍ以下である。微細突起１１の平均高さとしては、１２０ｎｍ以上３８０ｎｍ以下が好ましい。微細突起１１の平均高さの平均径に対する比としては、１／２以上３／２以下が好ましい。微細突起１１の頂点の曲率半径としては、６０ｎｍ以上１μｍ以下が好ましい。上記スティッキング防止層８が帯電防止剤を含有するとよい。【選択図】図１