| 摘要 |
An optical displacement sensor has an optically detectable coded track movable relative to a mask. The track is illuminated by light conducted by an optical fibre from a remote light source and the image of the track is focussed by a mirror on to the aperture of a second fibre. The mirror is mechanically movable to scan the image of the code over the fibre end to produce light pulses in the fiber which can be decoded at a remote receiver. The mirror is actuated electrically by electric energy from a photo-voltaic cell illuminated by light from a third fiber. Bits in the coded track are only partially opaque but the mask is fully opaque so the edges of the mask can be recognized by the receiver as the mirror is scanned.
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