Method and apparatus for selective blanking of a motor vehicle license plate

Abstract

A license plate assembly includes a frame receiving a conventional license plate and at least one blanking flash generator arranged to generate a blanking flash at the license plate in response to a monitoring flash from an external monitoring device. The monitoring device is designed to take an image of the license plate and the blanking flash is obscuring the license plate to prevent or interfere with the taking of the image.

I claim: 
     
       1. A license plate assembly for a motor vehicle, comprising:
 a frame sized and shaped to extend around and receive a license plate; 
 a sensor arranged in said frame to sense a monitoring flash generated by a license plate recording device; 
 a control device coupled to said sensor and arranged in said frame; and 
 a plurality of blanking flash generators that are each coupled to said control device and housed in said frame, said control device configured to control an operation of the blanking flash generators to generate a blanking flash in response to said monitoring flash and obscure said license plate and thereby prevent the license plate recording device from recording at least part of said license plate. 
 
     
     
       2. The license plate assembly of  claim 1 , further including a capacitor bank selectively coupled to said flash generators. 
     
     
       3. The license plate assembly of  claim 1 , wherein said flash generators each emit a strobe flash. 
     
     
       4. The license plate assembly of  claim 1 , wherein said sensor is adapted to receive several sequential monitoring flashes and said control circuit is adapted to generate a corresponding blanking flash following each monitoring flash. 
     
     
       5. The license plate assembly of  claim 4 , wherein some of said blanking flashes have a first intensity and some of the blanking flashes have a second intensity higher than said first intensity. 
     
     
       6. A license plate assembly for a motor vehicle, and comprising:
 a frame sized and shaped to extend around a perimeter of a license plate and receive the license plate; 
 a sensor disposed in said frame and arranged to sense a monitoring flash generated by a license plate recording device; 
 a control device disposed in said frame and coupled to said sensor; and 
 a plurality of flash generators mounted in said frame and coupled to said control device, configured to generate said blanking flash at said license plate, 
 wherein said control device is configured to control an operation of the blanking flash generators to each generate a blanking flash in response to said monitoring flash and direct said blanking flash at the license plate to obscure said license plate and thereby prevent the license plate recording device from recording at least part of said license plate. 
 
     
     
       7. The license plate assembly of  claim 6 , wherein said flash generators emit respective blanking flashes directed at said license plate in response to control signals from said control device. 
     
     
       8. The license plate assembly of  claim 7 , wherein said flash generators are arranged around said perimeter of said license plate. 
     
     
       9. The license plate assembly of  claim 8 , wherein the license plate is generally rectangular with two long and two short sides. 
     
     
       10. The license plate assembly of  claim 9 , wherein said flash generators are disposed adjacent to said short sides. 
     
     
       11. The license plate assembly of  claim 6 , wherein said frame includes a front surface with a transparent portion, said sensor being disposed behind said transparent portion. 
     
     
       12. The license plate assembly of  claim 11 , wherein said transparent portion is adapted to filter out infrared radiation.