Position detecting apparatus, and optical apparatus comprising this and position detecting method

A position detecting method of adjusting gains and offsets of at least two phases of position detecting signals that change periodically or sinusoidally and are outputted from a position sensor according to movement of an object, and obtaining a position of the object on the basis of the position detecting signals whose gains and offsets are adjusted, comprising:

• a step of counting a wave number of the position detecting signals from a reference position;
• a step of obtaining adjustment data corresponding to the wave number that is counted;
• and
• a step of adjusting gains and offsets of the position detecting signals on the basis of the obtained adjustment data.

A position detecting apparatus that detects a position of an object, comprising:

• a position sensor that outputs at least two-phases of position detecting signals that change periodically or sinusoidally according to movement of the object;
• a signal adjusting unit that performs gain and offset adjustment of each of the position detecting signals by using adjustment data;
• a calculation unit that obtains a position of the object on the basis of the position detecting signals whose gains and offsets are adjusted;
• and
• a memory circuit that can store the adjustment data,
• wherein the memory circuit maintains storing the adjustment data at least until the position detecting apparatus operates this time;
• and
• wherein at the time of the operation start at this time, the signal adjusting unit performs the gain and offset adjustment by using the adjustment data which is stored in the memory circuit.