Patent ID: 7812681

Claim:
A driver device which is connected with a vibrator to form an oscillation loop and causes the vibrator to produce driving vibrations when measuring a physical quantity using an output signal obtained by synchronously detecting a detection signal output from the vibrator, the driver device comprising: a gain control amplifier which causes the vibrator to produce the driving vibrations by controlling an oscillation amplitude in the oscillation loop; and a comparator which generates a synchronous detection reference signal based on a signal in the oscillation loop; the driver device causing the vibrator to produce vibrations using an output from the comparator in a state in which a gain in an oscillation loop formed by the vibrator and the comparator is set to be larger than unity, and then causing the vibrator to produce the driving vibrations by controlling an oscillation amplitude in an oscillation loop formed by the vibrator and the gain control amplifier; and the comparator having an output current limiting function.