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:
Oct. 09, 1984
Filed:
Nov. 10, 1983
Kenji Onogi, Yokohama, JP;
Nippon Kogaku K.K., Tokyo, JP;
Abstract
A shutter speed determining apparatus adapted for a photographing apparatus in a microscope includes a photo multiplier as photoelectric element. The photo multiplier receives light transmitted through an objective lens and transforms the light into an electric signal. The output signal from the photo multiplier is compared with a reference signal which has two different levels, high and low. When the output signal is higher than the high reference level, a first signal is produced and when it is lower than the lower reference level, a second signal is produced. When the first signal is produced, the sensitivity of the photo multiplier is decreased. On the contrary, when the second signal is produced, the sensitivity is increased up. A correction coefficient is produced in accordance with the sensitivity of the photo multiplier. An arithmetic unit determines a proper shutter speed from the output of the photo multiplier and, in addition, the output of correction coefficient output circuit.