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:
Nov. 17, 1992
Filed:
Dec. 05, 1991
Akira Matsueda, Tachikawa, JP;
Olympus Optical Co., Ltd., Tokyo, JP;
Abstract
In this invention, a reading signal detected by a photodetector is input into two differentiating circuits of different differential constants. The first differentiating circuit differentiates the reading signal with the differential constant larger than that of, for example, the second differentiating circuit and lowers the level of the noise component present as mixed in the reading signal. The first comparing circuit removes the noise component, for example, below the threshold value. The second differentiating circuit differentiates the reading signal with the differential constant converting the peak point of the reading signal, for example, of the above mentioned photodetector to a zero crossing point. The second comparing circuit compares the differential signal of the above mentioned differentiating circuit with the threshold value set, for example, on the zero level and makes the output signal rise, for example, in the center position of an information pit. A bivalued signal logical circuit obtains a bivalued signal made by bivaluing the reading signal from the respective output signals of the first and second comparing circuits.