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:
Feb. 17, 1998
Filed:
Jun. 05, 1995
Dainippon Screen Manufacturing Co., Ltd., Kyoto, JP;
Abstract
An illumination apparatus is disclosed which efficiently irradiates an irradiation surface without destroying the symmetry of an illuminance distribution at the irradiation surface. A light source is displaced from a center of curvature of a spherical mirror in a direction in a displacement plane which includes an axis of symmetry of the spherical mirror so as to form a light source image at a position off the light source. Due to this, a ray from the spherical mirror passes off the light source (i.e., the position of the light source image), and therefore, a reflection ray is not shielded, absorbed nor otherwise disturbed by the light source, which in turn prevents deterioration in the efficiency of utilization of light. Further, the light source, the spherical minor and the lens are assembled into a light source unit which is inclined at an angle about a principal point of the lens with respect to a central axis of the irradiation surface and displaced a certain distance in a displacement direction which is perpendicular to the central axis. Hence, the illuminance distribution at the irradiation surface is adjusted and the symmetry of the illuminance distribution at the irradiation surface is improved.