Optical type displacement detecting device

摘要: An optical type displacement detecting device including a main scale and an index scale, wherein pitch of first grating formed on the is set at P second P/n, thereby producing divided detection signal having P/n. Furthermore, (u+v) P/u or P/(2u) (u gap between diffusive light source v gratings), so that collimator lens can be dispensed with. Further, higher harmonic components are utilized, whereby substantially Q/u Q/(2u) (Q=P/m, m whole number 2 more), preventing from being into small ones.