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. 18, 1990
Filed:
Sep. 21, 1988
Brian J Bayley, Palo Alto, CA (US);
Michael J Brosnan, Fremont, CA (US);
Neil Hochgraf, Rochester, NY (US);
Hewlett-Packard Company, Palo Alto, CA (US);
Abstract
An optical system for a bar code scanner has a working range that is not determined by the lens aperture, but by the dimension and orientation of the detector. In the preferred embodiment, the desired working range is imaged onto a detector array using a modified Scheimpflug arrangement. The array in the first Scheimpflug plane with respect to the lens defines a second Scheimpflug plane that intersects the bar code tag to be read. So long as the bar code tag intersects the image of the detector array in the second Scheimpflug plane, a portion of the image of the bar code tag will be in focus on at least one of the elements of the detector array. The lens aperture can be as large as desired to maximize resolution and minimize illumination needs without adversely affecting the working range. The scanner's bar code illumination can be directed along the second Scheimpflug plane, which is off the optical axis of the lens. With separate illumination and detection paths, the optical system of the invention does not require beam splitters or mirror/aperture arrangements needed by the conventional systems.