Vehicle license plate imaging and reading system for day and night

US7016518B2 · kind B2 · utility

Assignee

• Extreme CCTV Inc. · CA

Inventor

• Mark Vernon · North Shields, GB

Key dates

• Filing date: Mar 15, 2002
• Grant date: Mar 21, 2006
• Expiry date: Oct 24, 2023

Classification

• Technology area (CPC G): Physics
• CPC primary: G08G1/054
• WIPO field: Control
• WIPO sector: Instruments

Abstract

This invention provides an infrared illuminator and camera system for imaging of auto vehicle license plates. The system works in ambient light conditions, ranging from bright sunlight, to dim light, to dark, to zero ambient light. It yields high-contrast imaging of the letters and numbers on retro-reflective license plates. The images of the license letter and number combinations can be read manually by a remote operator. They can be converted to text format with optical character recognition computer hardware and software. The text data can then be compared to data files listing license numbers to provide further data about the owner of a licensed vehicle. A decision can be made quickly about whether to allow a vehicle to proceed through a gate, or whether to take other action. The system uses a mono camera that is enhanced for infrared sensitivity and combined with a high power infrared illuminator to maximize range at night, and with shutter speeds set up to capture clear license plate pictures even with fast moving vehicles and even with their headlights on and interfering with human observation of the license plates. Optical filtering to pass infrared in the range of the illu…