Patent ID: 7050219

Claim:
A light-modulating element having a flat shape, which comprises: a total-reflection optical member having such a property that at least part of incident light introduced into the light-modulating element is totally reflected at an total reflection plane provided at a side opposite to the incident-light introduction side and the incident light does not substantially go out through a side opposite to the incident-light introduction side; and a light-coupling element which is disposed on the total reflection plane side of the total-reflection optical member and serves to selectively couple with the incident light and take out the same from the total reflection plane; wherein the total-reflection optical member has, disposed therein, an optical element which selects a light path, and that at least part of the planar incident light introduced into the total-reflection optical member is introduced into the optical element selecting a light path and substantially all the incident light thus introduced is reflected by total reflection at an interface of a layer constituted by the total-reflection optical member.