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:
Mar. 12, 2002
Filed:
Jun. 21, 2000
Lihu Chiu, Arcadia, CA (US);
RJS Systems International, Irvine, CA (US);
Abstract
A bar code scanner/verifier rapidly analyzes reflections of a scanning laser beam to determine whether or not a scanned line portion contains a bar code, so analysis of a bar code begins only when a legitimate bar code is present. The apparatus reads transitions in reflectance and indicates that a bar code is not present when the transitions are not large enough to qualify for a bar code, and when there are not enough transitions per unit distance. The circuit does this by generating MAX minus MIN, where MAX continually decreases over time but is raised every time a high reflectance is encountered, and MIN continually increases over time but is lowered every time a low reflectance is encountered. When MAX minus MIN drops below a programmable predetermined noise level, the circuit indicates that there is no bar code. Another circuit counts the number of transitions in a region where MAX minus MIN is above the noise level, and indicates that a bar code is present only if at least a certain number of transitions, e.g. 17, are found within a predetermined scan distance such as 2 cm. The circuit for detecting the presence or absence of a bar code can be implemented in analog, or in software using sparse data, e.g. every 4 or 8 samples.