Reflection type rotary optical coder

摘要

The optical coder includes a reflection plate (1), with which a coding light reflection patter (31) is formed on a transparent substrate. The coding light reflection pattern (31) is formed so that a metal layer is vaporised on the surface of the transparent substrate (2). This metal layer is superimposed by a shadow layer (4), from a photosensitive material on the surface of the vaporised metal layer. The shadow layer is partially etched, in order to partially expose the vaporised layer, for the forming of the coding light reflection pattern.