Tuning fork gyro with sense plate read-out

• Main Author: WEBER, MARK W
• Format: Patent
• Language: English; French; German
• Published: 18.07.2012
• Subjects: GYROSCOPIC INSTRUMENTS; MEASURING; MEASURING DISTANCES, LEVELS OR BEARINGS; NAVIGATION; PHOTOGRAMMETRY OR VIDEOGRAMMETRY; PHYSICS; SURVEYING; TESTING

A micro-electromechanical (MEM) device includes a proof mass (10) resiliently mounted to a substrate (28). The proof mass has first (32a) and second (32b) combs formed on opposite sides thereof and is electrically coupled to ground. A fixed drive comb (22) is interleaved with the first comb (32a) of the proof mass. A fixed pick-off comb (24) is interleaved with a portion of the second comb (32b) of the proof mass (10). A fixed bias comb (34a) is interleaved with the second comb (32b) of the proof mass (10). A substantially direct current (DC) bias (V B ) is applied to the fixed bias comb (34a). A substantially constant voltage (V S+ ) is also exerted on a sense plate (18) beneath the proof mass (10). The sense plate (18) and bias comb (34a) are coupled to a charge amp (20) through capacitors (40a, 46a) such that transient currents induced by motion of the proof mass (10) will cause current to flow to a charge amp (20).