Low frequency optical shutter and driver

An optical shutter suitable for modulating a light beam, the optical shutter comprising:

• (a) a frame having at least one aperture for passing a light beam through the frame;
• (b) at least one shutter blade proximate the frame having a bottom end and a top end with the top end comprising of a first sector and a second sector wherein the first sector has different optical properties than the second sector;
• (c) a motor means comprising of a phase one coil set and a phase two coil set for pivotally rotating the shutter blade over a limited angular range in a clockwise and counter-clockwise direction such that the first sector is aligned with the aperture when the shutter blade is rotated in one direction and the second sector is aligned with the aperture when the shutter blade is rotated in the other direction;
• (d) means for supplying current through the phase one coil set to ground;
• (e) clock means for providing the operating frequency of the optical shutter;
• and
• (f) amplifier means for providing current through the phase two coil set to ground in response to the clock means.

A circuit for driving an optical shutter having a phase one coil set and a phase two coil set, the circuit comprising:

• (a) means for supplying current through the phase one coil set to ground;
• (b) clock means for providing the operating frequency of the optical shutter;
• and
• (c) amplifier means for providing current through the phase two coil set to ground in response to the clock means.