Patent 8427752 was granted and assigned to Olympus Group on April, 2013 by the United States Patent and Trademark Office.
An illumination apparatus includes a light source and a collimator optical system converting light emitted from the light source to approximately-parallel light. The collimator optical system includes, in an order of proximity to the light source, a first lens having a positive power and including an approximately-flat surface and an aspheric surface, and a second lens having a positive power.