초록 ▼

A scanning system is capable of open or closed loop operation for generating arbitrary rotatable multi-dimension with frequency compensation of scanning element. The system includes at least two scan elements positioned substantially orthogonally to each other for generating the arbitrary rotatable

A scanning system is capable of open or closed loop operation for generating arbitrary rotatable multi-dimension with frequency compensation of scanning element. The system includes at least two scan elements positioned substantially orthogonally to each other for generating the arbitrary rotatable multi-dimensional scanning patterns. A power supply is responsive to respective control signals from a set of drive waveforms as inputs to the at least two scan elements. A controller includes an information processing system to store in digital form the desired set of arbitrary rotatable multi-dimensional scan patterns. In a closed loop mode, the controller stores feedback parameters for each scan element with a particular rotational angle and a feedback value at a particular frequency. The controller uses a feedback signal from the scan elements to compute an error signal indicative of the difference in frequency response between the desired frequency response and the actual frequency response and the difference in phase between the scanning elements. The error signal adjusts the control signal provided to the power supply to conform the actual and desired frequency response of the scanning elements thereby substantially eliminating distortion in pattern generation. In an open loop mode, the scanning system is operated without a feedback signal, but the drive waveforms are regularly fine tuned in amplitude and phase to compensate for changes in frequency response due to temperature variations and aging of the scanning elements.

대표청구항 ▼

[ We claim:] [1.] A scanning system capable of open or closed operation for generating arbitrary rotatable multi-dimensional scan patterns comprising:a) at least two scan elements for generating the arbitrary rotatable multi-dimensional scan patterns in response to a set of multi-frequency drive wav

[ We claim:] [1.] A scanning system capable of open or closed operation for generating arbitrary rotatable multi-dimensional scan patterns comprising:a) at least two scan elements for generating the arbitrary rotatable multi-dimensional scan patterns in response to a set of multi-frequency drive waveforms with each scan element optionally providing a feedback signal indicative of the actual position of the corresponding scan element;b) a driver responsive to a control signal for generating and supplying the set of drive waveforms to the at least two scan elements;c) controller for:i) storing a set of scan pattern parameters corresponding to a desired arbitrary rotatable multi-dimensional scan pattern;ii) storing for each scan element at least two sets of reference parameters:a) a first set of reference parameters defining angular characteristics for each scan element; andb) a second set of reference parameters defining a frequency characteristics for each of said scan elements;iii) a first means for using the feedback signal to determine a group of actual scan element parameters;iv) a generator for generating a set of correction signals indicative of the difference between the actual scan element parameters and the corresponding reference scan element parameters; andv) a second means for providing a control signal to the driver based upon the set of generated correction signals; reby the scan elements are driven in concert and are compensated as a group for any scan pattern distortion.