Patent ID: 6135598
Filing Date: 2000-10-24
Classification: H04N

Abstract:
An optical device for irradiating a surface of an object with light, said device comprising:a light source having an optical axis; anda light path changing element arranged between said light source and said object for changing a light path along which a part of a light beam emitted by the light source travels toward a central portion of the surface of the object into a light path along which said part of the light beam travels toward a peripheral portion of said surface of said object, without changing parallelism of said light beam,said light source emitting light beams to irradiate an area having a first size located about said optical axis at a first distance from the light source, said light path changing element being located about said optical axis at a second distance from the light source and having a second size smaller than said first size so that a part of the light beams emitted by the light source pass through said light path changing element and reach said object, and another part of the light beams emitted by the light source reach said object without passing through said light path changing element.