Torsion oscillator voltage control driver with each of dual voltage polarity for each of dual channel
View Patent ↗A system for driving a torsion based on frequency, amplitude and offset control signals includes a pulse width modulator subsystem configured to generate output pulses having controlled pulse durations alternately to each of two channels, the output pulses encoding the frequency, amplitude and offset control signals. A driver circuit is configured for driving the torsion oscillator with a voltage of one polarity during a pulse output to the one of the channels, and a voltage of opposite polarity during a pulse output to the other of the channels.
1. A system for driving an oscillator based on control signals, comprising:
a modulator subsystem configured to generate output pulses having controlled pulse durations alternately to each of two channels, the output pulses encoding at least frequency and amplitude control signals; and
a driver circuit configured for driving the torsion oscillator with a voltage of one polarity during a pulse output to the one of said channels, and a voltage of opposite polarity during a pulse output to the other of said two channels.
2. The system of claims 1 , which further comprises the modulator subsystem generating an offset control signal.
3. A system for driving a torsion oscillator based on frequency, amplitude and offset control signals, comprising:
a modulator subsystem configured to generate output pulses having controlled pulse durations alternately to each of two channels at an alternating frequency corresponding to the frequency control signal;
the duration of output pulses generated to one of said two channels being controlled based on the amplitude control signal summed with the offset control signal;
the duration of output pulses generated to the other of said two channels being controlled based on the amplitude control signal summed with the negative of the offset control signal; and
a driver circuit connected for driving the torsion oscillator with a voltage of one polarity during a pulse output to the one of said two channels, and with a voltage of opposite polarity during a pulse output to the other of said two channels.
4. The system of claim 3 , wherein said modulator subsystem comprises:
first and second pulse duration modulators each configured to generate, when triggered, a pulse having a controlled pulse duration; and
a first adder connected to a pulse duration control input of said first pulse duration modulator, said first adder generating a first pulse duration control signal based on the amplitude control signal summed with the offset control signal;
a second adder connected to a pulse duration control input of said second pulse duration modulator, said second adder generating a second pulse duration control signal based on the amplitude control signal summed with the negative of the offset control signal.
5. The system of claim 3 , which further comprises a feedback controller for generating at least the amplitude and offset control signals.
6. A bidirectional imaging apparatus comprising:
a light source for generating a light beam;
a torsion oscillator having a reflective surface disposed in the path of the light beam for oscillating and scanning the light beam through a scan path including an imaging window occupying a portion of the scan path, the light beam being scanned across the imaging window in a forward direction and a reverse direction;
sensors for sensing the position of the light beam in the scan path;
feedback controllers for generating frequency, amplitude and offset control signals based on signals from said sensors;
a pulse width modulator subsystem configured to generate output pulses having controlled pulse durations alternately to each of two channels at an alternating frequency corresponding to the frequency control signal;
the duration of output pulses generated to one of said two channels being controlled based on the amplitude control signal summed with the offset control signal;
the duration of output pulses generated to the other of said two channels being controlled based on the amplitude control signal summed with the negative of the offset control signal; and
a driver circuit connected for driving the torsion oscillator with a voltage of one polarity during a pulse output to the one of said two channels, and with a voltage of opposite polarity during a pulse output to the other of said two channels.
7. The apparatus of claim 6 , wherein said pulse width modulator subsystem comprises:
first and second pulse duration modulators each configured to generate, when triggered, a pulse having a controlled pulse duration; and
a first adder connected to a pulse duration control input of said first pulse duration modulator, said first adder generating a first pulse duration control signal based on the amplitude control signal summed with the offset control signal;
a second adder connected to a pulse duration control input of said second pulse duration modulator, said second adder generating a second pulse duration control signal based on the amplitude control signal summed with the negative of the offset control signal.