Patent ID: 6650765
Filing Date: 2003-11-18
Classification: G08G

Abstract:
A vehicle and license plate imaging system, comprising:a video camera for providing an image of a vehicle and a license plate in the dark and at night, and in which it is unknown if said license plate will be non-retro-reflective or retro-reflective; a first polarizing filter mounted in front of the video camera and having a first polarizing orientation; a low-level floodlight for providing an illumination of said vehicle and license plate for the video camera; a flash lamp providing for a flash illumination of said vehicle and license plate for the video camera; a visual-spectrum cutout filter placed between the flash lamp and said vehicle, and providing for a blockage of human-visible light spectra that would otherwise reach said vehicle, and providing for a combination of a first light with wavelengths less than 400 nanometers and a second light with wavelengths more than 700 nanometers at the fringes of the visible spectrum to contrast a variety of color combinations used in said license plate; a second polarizing filter placed between the flash lamp and said vehicle, and having a second polarizing orientation that is orthogonal to said first polarizing orientation and providing for cross Polarization of said flash illumination; wherein, a reflected light from the flash lamp with said second polarizing orientation that is returned from said vehicle and license plate is blocked by the first polarizing filter; and wherein, the low-level floodlight is able to provide sufficient illumination for the camera if said license plate is a retro-reflective type.