OPTICAL FILM, POLARIZATION PLATE, LIQUID CRYSTAL PANEL, AND IMAGE DISPLAY DEVICE

• Main Authors: MINAKOSHI KIYOKA, FURUI GEN, OKUMI SHOICHIRO, IWATA YUKIMITSU, EGUCHI JUNYA
• Format: Patent
• Language: English; Japanese
• Published: 07.01.2016
• Subjects: 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; LAYERED PRODUCTS; LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT ORNON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM; NON-LINEAR OPTICS; OPTICAL ANALOGUE/DIGITAL CONVERTERS; OPTICAL ELEMENTS, SYSTEMS, OR APPARATUS; OPTICAL LOGIC ELEMENTS; OPTICS; PERFORMING OPERATIONS; PHYSICS; TECHNIQUES OR PROCEDURES FOR THE OPERATION THEREOF; TRANSPORTING

PROBLEM TO BE SOLVED: To provide an optical film, a polarization plate, a liquid crystal panel, and an image display device capable of suppressing the occurrence of interference fringes, dispensing with observation of cloudiness, and achieving reduction in manufacturing cost.SOLUTION: According to one aspect of the present invention, an optical film 10 comprises: a light transmissive substrate 11; and a functional layer 12 provided on the light transmissive substrate 12. The optical film 10 is configured so that the functional layer 12 includes an irregular surface 12A that constitutes a surface of the optical film 10, and, in an angle distribution of reflection light intensities measured in a plane including both a normal direction N and a parallel light progress direction T in a state in which parallel light progressing in a direction inclined at 10° from the normal direction N is radiated on the irregular surface 12A of the functional layer 12, a value obtained by subtracting a width in an angle range in which the reflection light intensity equal to or higher than a half of the maximum reflection light intensity from a width of an angle range in which the reflection light intensity equal to or higher than one-hundredth of the maximum reflection light intensity is not less than 0.7° and not more than 1.4°. 【課題】干渉縞の発生を抑制でき、白濁感が観察されず、かつ製造コストの低減を図ることができる光学フィルム、偏光板、液晶パネル、および画像表示装置を提供する。【解決手段】本発明の一の態様によれば、光透過性基材１１と、光透過性基材１１上に設けられた機能層１２とを備える光学フィルム１０であって、機能層１２が光学フィルム１０の表面をなす凹凸面１２Ａを有し、光学フィルム１０の法線方向Ｎから１０?傾斜した方向に進む平行光を機能層１２の凹凸面１２Ａに照射した状態で、法線方向Ｎおよび平行光の進行方向Ｔの両方向を含む平面内にて測定された反射光強度の角度分布において、最高反射光強度の１／１００以上の反射光強度が測定される角度域の幅から最高反射光強度の１／２以上の反射光強度が測定される角度域の幅を引いた値が、０．７?以上１．４?以下である、光学フィルム１０が提供される。【選択図】図２