The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 12, 2011
Filed:
Feb. 20, 2009
Masashi Tatsukawa, Shizuoka, JP;
Masashi Tatsukawa, Shizuoka, JP;
Koito Manufacturing Co., Ltd., Tokyo, JP;
Abstract
Light having entered a light transmitting member through a predetermined point on an optical axis undergoes internal reflection in a front surface perpendicular to the optical axis, then undergoes internal reflection again in a rear surface composed of a paraboloid of revolution having a focal point at a position of plane symmetry with the predetermined point, and then exits the front surface. A mirror-finished annular region around the optical axis in the front surface has an outer peripheral edge set to be near a position where the incident angle of the light emitted from the light emitting element is equal to a critical angle, and an inner peripheral edge near a position where the light having undergone internal reflection in the front surface enters a position immediately behind the outer peripheral edge in the rear surface.