| 摘要 |
PROBLEM TO BE SOLVED: To provide an encoder capable of reducing an amount of light that is reflected in a non-gradation pattern region 22 except a gradation pattern region 21 and then enters a light receiving unit 5, and to provide a manufacturing method for the same.SOLUTION: An encoder 10 comprises a code plate 1, a light projection unit 4 and a light receiving unit 5. The light projection unit 4 emits light 3 to the code plate 1 and the light receiving unit 5 receives the light 3 reflected from the code plate 1. The code plate 1 includes: a gradation pattern region where a high-reflection area capable of reflecting the light 3 emitted by the light projection unit 4 and a low-reflection area having lower reflectivity to the light 3 emitted by the light projection unit 4 than the high-reflection area are arranged alternately in a moving direction of the code plate 1; and a non-gradation pattern region that is adjacent to the gradation pattern region and has low reflectivity to the light 3 emitted by the light projection unit 4. The non-gradation pattern region has a diffusion structure that causes the light 3 emitted by the light projection unit 4 to advance toward a direction except the light receiving unit 5. |
