Patent ID: 7545569

Claim:
An optical apparatus comprising: a) a light guide; b) an optical member comprising a body of optically transmissive material and having a textured major surface with an everted configuration or an inverted configuration; the optical member being oriented such that the textured major surface receives light from said light guide and then said light passes through said body; the textured surface comprising a first plurality of non-intersecting elongate features with a predetermined pitch and a second plurality of non-intersecting elongate features with a predetermined pitch; the pluralities being angled with respect to each other by less than about 90° and intersecting each other so as to form total internal reflection structures; c) a spatial light modulator with rows or columns of pixels for receiving light from the optical member at a major surface; d) adjacent first and second elongate features of the first plurality and adjacent first and second elongate features of the second plurality forming a projection extending away from said body and reaching an apex line for an everted configuration of the body or forming a projection extending towards said body and reaching an apex line for an inverted configuration of the body; and e) the apex line being shorter than either the pitch of the first plurality and the pitch of the second plurality.