Patent ID: 6199992
Filing Date: 2001-03-13
Classification: F21V,G02B,G02F

Abstract:
A reflector for a liquid crystal display device having a total-reflective or a semi-reflective reflecting surface, wherein said reflecting surface comprises a plurality of fine circular-arc concave curves arranged side-by-side when viewed in cross section, and wherein:the maximum tilt angle of each of said circular-arc concave curves is set substantially to one half of an effective viewing angle;the pitch of said circular-arc concave curves is 50 .mu.m or less;the surface of the reflector has n irregularities;the height h.sub.n of each of the irregularities is given by the formula h.sub.n =r(1-cos 2.sub.n) and the pitch P.sub.n of each of the fine circular-arc curves is given by the formula P.sub.n =2r(sin 2.sub.n), wherein 2.sub.n is the tilt angle of a tangent to one of the fine circular-arc concave curves and r is the radius of the fine circular-arc concave curve of which 2.sub.n is the tangent;the tilt angle .theta..sub.n is in the range of a predetermined angle;when a successive predetermined number of said circular-arc concave curves are taken as one set, different pitches of said circular-arc concave curves are included in said one set, and several units of said circular-arc concave curves are repeatedly formed, said one set of circular-arc concave curves being one unit; andtransparent upper and lower substrates are held by a predetermined gap formed therebetween, a liquid crystal material is sealed in the gap, the reflector is provided on the lower substrate in the gap, and the height h.sub.n of the concave surface is one-fifth of the size of the gap.