Patent ID: 6842246

Claim:
An alignment system comprising: a first module; a first plurality of emitters located at defined locations on a face of the first module, positioned to emit signals of a known intensity distribution away from the face of the first module; a first receiver configuration located on the face of the first module, having a known sensitivity distribution; a second module; a second plurality of emitters located at defined locations on a face of the second module, positioned to emit signals of a known intensity distribution away from the face of the second module; a second receiver configuration located on the face of the second module, having a known sensitivity distribution; a trigger signal generator configured to fire the first plurality of emitters of the first module in a predetermined pattern to generate signals sensed by the second receiver configuration of the second module, and to fire the second plurality of emitters of the second module in a predetermined pattern to generate signals sensed by the first receiver configuration of the first module; a converter configuration arranged to obtain and convert the signals received by the first and second receiver configurations into data representative of the signals sensed by the receiver configurations; and a processing system configured to receive the data from the converter configuration, and to compute an offset between the faces of the first and second modules.