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. 02, 2004
Filed:
Apr. 10, 2003
Norio Nakamura, Yokohama, JP;
Nobuyasu Goto, Yokohama, JP;
Takaaki Shimizu, Tokyo, JP;
Yutaka Ichinohe, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A barcode scanner comprising a laser driving circuit to drive a laser by a pulse signal generated by an oscillator, a preamplifier to amplify a voltage of a barcode signal from a photodetector corresponding to a reflected light from a barcode scanned by a light output of the laser driven by the pulse signal, a high-pass filter to remove a direct current component contained in an output signal of the preamplifier, a variable gain amplifier which controls an amplification gain of an output signal of the high-pass filter and performs automatic gain control to set an output level almost constant, a synchronous detector to detect a pulse signal contained in an output signal of the variable gain amplifier in synchronization with the output pulse of the oscillator, and a binarization circuit to binarize an output signal of the synchronous detector.