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:
Jan. 22, 1991
Filed:
Oct. 31, 1989
Applicant:
Inventor:
Seiji Nanri, Shiga, JP;
Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
355 69 ; 355 77 ;
Abstract
An apparatus for preventing degradation of a light source in an exposure apparatus using a halogen lamp as a light source includes an intermittent turning on circuit for intermittently turning on the halogen lamp, a counter for accumulating the intermittent on-time of the halogen lamp, a determining apparatus for determining whether or not the counted value has reached a prescribed value, and a circuit for keeping on the halogen lamp for realizing a halogen cycle. When the determining apparatus determines that accumulated value of the intermittent on-time of the halogen lamp has reached the prescribed value, the halogen lamp is kept on continuously for a period of time necessary for the halogen cycle.