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:
Dec. 15, 1987
Filed:
Oct. 29, 1986
Keiichiro Sakato, Kawasaki, JP;
Nippon Kogaku K.K., Tokyo, JP;
Abstract
An apparatus for controlling the exposure for successively exposing or printing the same pattern in the different areas on a photosensitive surface of a photosensitive substrate such as a wafer or a photographic mask. The intensity of the light projected onto the photosensitive surface from a light source through a shutter is detected in response to the full opening of the shutter. The required exposure time is computed in accordance with the detection result and a desired exposure and the closing operation of the shutter is started when there is a special relation between the measured shutter time count and the computed result. To prevent any waste of the light source, the light source performs its light emitting operation such that alternate relatively high-intensity emission and relatively low-intensity emission are periodically repeated and the average input power to the light source during the interval is maintained at a predetermined value.