Patent ID: 7022963

Claim:
A laser receiver for detecting the position of incidence of a beam of laser light thereon, comprising: a first photodetector and a second photodetector aligned in series with each other and spaced apart from each other by a gap, the first and second photodetectors detecting the radiation of the laser light to produce corresponding first and second current signals; a first voltage converter circuit coupled to the first photodetector, and a second voltage converter circuit coupled to the second photodetector, each voltage converter circuit separately receiving a corresponding one of the first and second current signals, and producing corresponding electronic signals; a first band-pass filter coupled to the first voltage converter circuit and a second band-pass filter coupled to the second voltage converter circuit, the band-pass filters filtering unnecessary electronic signals; a signal processing unit coupled to the first and second band-pass filters for amplifying and rectifying the electronic signals to produce corresponding first and second direct current voltage signals; a differential amplifier coupled to the signal processing unit and producing a difference corresponding to the first and second direct current voltage signals; an absolute value circuit coupled to the differential amplifier for producing an absolute difference corresponding to the difference; a compare circuit coupled to the absolute value circuit for comparing the absolute difference with the sum of the two direct current voltage signals to produce a compare value; a microprocessor coupled to the compare circuit for calculating the position of the laser light according to the compare value; and a display unit coupled to the microprocessor for displaying the position of the laser light.