| 摘要 |
PURPOSE:To attain the size and weight reduction of a detecting device and to make the device compact by bonding the light emitting element of a light emission device to a lead frame as a power supply line previously and molding it with transparent resin. CONSTITUTION:A main optical grating 12 and a slave optical grating 16 are formed in parallel and adjacently to 1st and 2nd members 10 and 14 which are made of light-transmissive materials and can move relatively. Then the detection light from the light emission device is photodetected 20 through both gratings 12 and 16. The relative movement distance between both gratings 12 and 16 is calculated by using the electric signal based upon variation in the quantity of photodetection caused by the relative movement between both gratings 12 and 16. At this time, the light emission device 18 has its light emission element 26 connected and fixed electrically to the leaf frame 24 of a power supply line. Further, the element 26 and part of the frame 24 are cast to form a resin mold 28. Then, a concave reflecting mirror 30 is provided to the element 26 on the opposite side from the member 10 to make light diffused from the element 26 parallel and reflect it toward the members 10 and 14. Thus, the manufacture process and cost of the light emission device 18 are reduced.
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