Control of an optical fiber scanner

A controller for an optical scanner that is driven to move in a desired pattern, comprising:

• (a) a reference signal source that produces at least one reference signal;
• (b) a feedforward controller that operates in accord with a model of the optical scanner and is coupled to the reference signal source to receive said at least one reference signal, said feedforward controller employing the model and said at least one reference signal to determine a feedforward signal required to produce movement of the optical scanner in the desired pattern;
• and
• (c) a feedback controller that is adapted to couple to a sensor to receive a sensor signal indicative of movement by the optical scanner, said feedback controller using the sensor signal to determine a feedback signal used to stabilize the controller and to reject disturbances of the optical scanner, wherein said feedforward signal and said feedback signal are combined to control a drive signal used to drive the optical scanner to move in the desired pattern.

A method for controlling an amplitude and a phase used to drive an optical scanner to move in a desired pattern, comprising the steps of:

• (a) providing at least one reference phase signal;
• (b) producing a phase signal output in response to said at least one reference phase signal and in response to a position signal that is indicative of a position of a moving portion of the optical scanner in regard to at least one of a pair of orthogonal axes;
• (c) providing at least one amplitude reference signal;
• (d) producing an amplitude signal output in regard to at least one of the pair of orthogonal axes in response to said at least one amplitude reference signal and in response to the position signal;
• and
• (e) combining the phase signal output and the amplitude signal output for each of least one of the pair of orthogonal axes, to produce a drive signal for use in driving the optical scanner to move in the desired pattern.

A method for controlling an amplitude and a phase used to drive an optical scanner to move in a desired pattern, comprising the steps of:

• (a) providing a reference signal for at least one of a pair of orthogonal axes;
• (b) using a model of the optical scanner to determine a feedforward signal required to produce movement of the optical scanner in the desired pattern, in response to the reference signal, for at least one of the pair of orthogonal axes;
• (c) producing a feedback signal for use in stabilizing control of the optical scanner and for rejecting disturbances of the optical scanner;
• and
• (d) combining the feedforward signal and the feedback signal to produce a drive signal for use in driving the optical scanner to move in the desired pattern relative to at least one of the orthogonal axes.

A method for controlling an optical scanner to produce a spiral scanning pattern, comprising the steps of:

• (a) providing sinusoidally varying reference signals for each of two orthogonal axes of motion for the optical scanner, one of said sinusoidally varying reference signals being substantially 90° out of phase with the other;
• (b) providing a periodically varying amplitude signal for each of the two orthogonal axes, said periodically amplitude signal having a substantially triangular waveform with a frequency substantially less than that of the sinusoidally varying reference signals;
• (c) combining the sinusoidally varying reference signal for one axis with the periodically varying amplitude signal to produce a drive signal for said one axis;
• and
• (d) combining the sinusoidally varying reference signal for the other axis with the periodically varying amplitude signal to produce a drive signal for the other axis.

A method for controlling an optical scanner to produce a propeller scanning pattern, comprising the steps of:

• (a) providing a sinusoidally varying reference signal for each of two orthogonal axes of motion for the optical scanner;
• (b) providing sinusoidally varying amplitude signals for each of the two orthogonal axes, one of said sinusoidally varying amplitude signals being substantially 90° out of phase with the other;
• (c) combining the sinusoidally varying reference signal with the sinusoidally varying amplitude signal for one axis to produce a drive signal for said one-axis;
• and
• (d) combining the sinusoidally varying reference signal with the sinusoidally varying amplitude signal for the other axis to produce a drive signal for the other axis.