Patent ID: 7227115

Claim:
A laser scanning system employing light-diffractive optics and mode detection and switching, said laser scanning system comprising: a laser light source for emitting a laser light beam; an optical subsystem, including at least one diffractive optical element, for directing a first portion of the laser light beam into a scanning region and directing a second portion of the laser light beam to an optical detector, wherein said optical detector generates a first electrical signal in response thereto; a temperature control element, in thermal contact with said laser light source, for adjusting temperature of said laser light source during each sampling period of said laser scanning system; signal processing and control circuitry, operably coupled between said optical detector and said temperature control element, for generating a second electrical signal representing change in characteristic wavelength of the laser light beam emitted from said laser light source based upon the first electrical signal, and generating a control signal for controlling said temperature control element so as to adjust the temperature of said laser light source based upon the second electrical signal; and wherein said signal processing and control circuitry controls said temperature control element so as to adjust the temperature of said laser light source in the event that said second electrical signal exceeds a predetermined threshold value; wherein said signal processing and control circuitry generates a binary mode switching signal indicating whether said second electrical signal representing a change in the characteristic wavelength of the laser light beam emitted from said laser light source exceeds said predetermined threshold value, wherein said binary mode switching signal is supplied to a microcontroller programmed to execute a control routine that controls said temperature control element so as to adjust temperature of said laser light source is response to the logic level of said binary mode switching signal; wherein said control routine controls said temperature control element so as to either heat or cool said laser light source when the logic level of said binary mode switching signal indicates that a change in the characteristic wavelength of said laser light source occurred in the last sampling period of said laser scanning system; and wherein said control routine controls said temperature control element to maintain the temperature of said laser light source when the logic level of said binary mode switching signal indicates that a change in the characteristic wavelength of said laser light source did not occur in the last sampling period of said laser scanning system.