| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a compact and highly accurate optical encoder.SOLUTION: The optical encoder has: a light source; a scale that is arranged to face the light source; a light receiving element that receives a luminous flux from the light source via the scale; and a signal processing circuit that processes an output signal of the light receiving element. A light emitting window of the light receiving element is configured to be an aggregate of a plurality of point light sources, and has a shape satisfying the following expression, where S is an entire area in the light emitting window being an integration range, Po(x1, y1) is a function expressing a light emission intensity distribution in a near filed at XY coordinates (x1, y1) of the light emitting window, p is a lattice pitch of the scale, N is a specific degree of a harmonic component (N:1, 2, 3, ...), and x2 is a displacement detection-direction axis on a light receiving element plane.</p> |
