Patent ID: 6781759
Filing Date: 2004-08-24
Classification: G02B

Abstract:
A reflector comprising a reflecting film formed on a surface having depressions and protrusions wherein:each of the depressions and protrusions has a vertex and comprises a curved surface formed so as to be convex up or convex down and a surrounding portion including a valley or a ridge surrounding the curved surface with an inflection point of the curved surface serving as a boundary between the curved surface and the surrounding portion; when the curved surface is convex up, the inflection point is on the valley side of the midpoint between the vertex and the valley, whereas when the curved surface is convex down, the inflection point is on the ridge side of the midpoint between the vertex and the ridge; and wherein cross-sectional shapes of the curved surfaces located on the surface having the reflecting film are made similar by defining the cross-sectional shapes by z=&agr;xa/2+&bgr;, where z is the height or depth of the depression or protrusion in the thickness direction, x is a coordinate along a linear line orthogonal to said z along the thickness direction and including a peak of the depression or protrusion in the horizontal direction, &agr; and &bgr; are constants, and the average value of â€œaâ€  for the protrusions is greater than 2 and not greater than 4.