Optical encoder with shielding means.

摘要

An optical encoder includes a moving scale (1), a light source (2) which is always kept lighted, a fixed slit (3) and a light receiving array (4) having a plurality of light receiving units (41, 42). The light from the light source (2) is radiated toward the moving scale (1), thereby to generate signal light for a plurality of channels. The signal light for each channel passes through the opening (31; 32) of the fixed slit (3). The light passed through the opening (31) enters the light receiving unit (41), while the light passed through the opening (32) enters the light receiving unit (42). A plate-shaped light shield member (5) is interposed between the fixed slit (3) and the light receiving array (4) to optically separate the light passed through the opening (31) toward the light receiving unit (42) from the light passed through the opening (32) toward the light receiving unit (42) and thereby to prevent crosstalk between the channels. <IMAGE>