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.

Date of Patent:
Jun. 25, 1991

Filed:

Mar. 24, 1989
Applicant:
Inventors:

Yoshiki Yoshida, Yokohama, JP;

Kiyoto Nagasawa, Yokohama, JP;

Yoshinobu Kagami, Yokohama, JP;

Assignee:

Ricoh Company, Ltd., Tokyo, JP;

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03M / ; H04N / ;
U.S. Cl.
CPC ...
341132 ; 341158 ; 341159 ; 358465 ;
Abstract

An apparatus for converting an analog image signal to a digital image signal based on a reference voltage, includes a counter having a control terminal, for counting a first signal and outputting a counted value in digital form, a D/A converter for converting the counted value to an analog voltage signal served as the reference voltage, an A/D converter for converting the analog image signal to the digital image signal based on the reference voltage generated by the D/A converter, and a comparator for comparing in magnitude the digital image signal and a threshold level used for limiting the magnitude of the digital image signal, thereby outputting a control signal based on the results of comparison. The counter continues to count the first signal until the control signal derived from the comparator is supplied to the control terminal of the counter.


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