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. 18, 2003
Filed:
Jan. 11, 2000
James Francis Alves, San Diego, CA (US);
Pulnix America, Inc., Sunnyvale, CA (US);
Abstract
A vehicle video imaging system comprises a white-light LED array for illuminating retro-reflective painted parts of a vehicle's license plate, a powerful flash with a visual spectrum cutout filter and a polarizing filter for illuminating any non-retro-reflective license plate paint and the vehicle itself. A video camera with a polarizing filter turned 90° relative to the one in front of the flash receives the illuminated image of the vehicle and its license plate. The retro-reflective paint of a license plate will return polarized light as it is received, so the white-light LED array will provide all the illumination needed by the camera to get a good high-contrast picture of the license plate. The polarizing filters will combine to block out most of the light from the flash that was returned still-polarized by the retro-reflective-paint license plate. All other surfaces that do not have retro-reflective paint will bounce-back and scatter the light from both the polarized flash and non-polarized light.