Patent ID: 8816269
Filing Date: 2014-08-26
Classification: G01D,G02B

Abstract:
1. A reflective optical scale for an encoder, in which a first region and a second region are alternately arranged on an underlying member, wherein, the first region has a reflecting member arranged on the underlying member, a layer which is arranged on the reflecting member and is made up of a first material, and a layer which is arranged on the layer made up of the first material and is made up of a second material, the second region has the layer which is arranged on the underlying member and is made up of the second material, the first material and the second material have transparency with respect to light of a wavelength λ, the first material has a lower refractive index of the light than the reflecting member and the second material, the second material has a lower refractive index of the light than the underlying member, and optical thicknesses of the first material and the second material are set so that a reflectance of the light of the first region is higher than the second region.