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. 25, 1979
Filed:
Aug. 23, 1978
Ryushi Shimokawa, Fuchu, JP;
Hitachi, Ltd., , JP;
Abstract
In a digital comparator wherein a period of time taken until one output signal of a decoder circuit coincides with one corresponding output signal of a frequency divider circuit is measured by comparing output signals of the decoder circuit and output signals of the frequency divider circuit, an output circuit of the decoder circuit and an output circuit of the frequency divider circuit are constructed of integrated injection logic (IIL) in order to build up wired AND circuits, and further, a NOR circuit which includes inverter circuits constructed of IIL and a common connection line for connecting outputs of the inverter circuits in common is disposed in order to receive respective outputs of the wired AND circuits. Especially, the digital comparator of this invention is effective for an automatic exposure control system of a camera.