Patent ID: 6584052
Filing Date: 2003-06-24
Classification: G02B,H04N

Abstract:
An optical scanning device, comprising:a scanning head with a light output; a focusing element to image light from said output onto a target surface; said focusing element being effective to image a first amount of return light returned from said target surface back to said output when said focusing element is properly focused; said focusing element being effective to image a second amount of said return light returned from said target surface back to said output when said focusing element is improperly focused; a detector in a return path of light in said scanning head, said detector generating an output responsive to said return light; a controller programmed to control a configuration of said focusing element responsive to said output such that said focusing element remains properly focused by maintaining said return light at said first amount; and wherein said first amount of return light is different from said second amount of return light.