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. 17, 1996
Filed:
Feb. 28, 1995
Fumio Ohtomo, Tokyo, JP;
Kenichiro Yoshino, Tokyo, JP;
Kabushiki Kaisha Topcon, Tokyo, JP;
Abstract
An apparatus for detecting a light signal is provided which includes a first frequency source for generating a clock signal having a fixed frequency, a light emitting portion constituted of at least a light emitting element which is driven based on the clock signal of the first frequency source and emits a light signal, and a light receiving portion disposed apart from the light emitting portion. The light receiving portion includes a light receiving element which receives the light signal emitted from the light emitting element, an amplifying circuit which amplifies the light signal received by the light receiving element, a converter which converts an analog signal given from the amplifying circuit into a digital signal, a second frequency source for generating a clock signal having a fixed frequency, and a summing portion which samples the digital signals given from the converter synchronously with the second frequency source plural times at regular intervals during at least one period of the light signal and then, during a plurality of the periods of the light signal, sums sampled values obtained in turn during the one period.