| 摘要 |
PROBLEM TO BE SOLVED: To provide a projection type encoder based on the three grid theory manufacturable by simple processes and at low cost. SOLUTION: This is a projection type linear encoder 1 comprising a movable plate 5 having transmitting grids 3 and a group of grid type photodiodes, and a reflection grid plate 7 having reflection grids 6 facing it. The movable plate 5 comprises a glass substrate 9 having the transmitting grids 3, and PD array chips 11 and 12 stuck on the substrate and provided with the group of photodiodes 4. The transmitting grids 3 on the glass substrate 9 are formed by etching a first light shielding film 16 formed on a glass substrate surface 15. Compared to cases of forming the transmitting grids and the group of photodiodes on a semiconductor substrate of large size, the projection type encoder can be manufactured by simpler processes and at lower cost. The grid pitch can be finer. COPYRIGHT: (C)2003,JPO
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