| 摘要 |
1,103,799. Determining angular displacement of a rotating shaft. GENERAL ELECTRIC CO. Dec.20, 1965 [Dec. 28, 1964], No.53790/65. Heading G1A. In an arrangement for sensing optically the relative angular displacement between the axis x of a rotating member and a reference axis y, a reflecting surface making an angle with a plane normal to the x axis is mounted on one end of the member, a collimated beam e, f of light is directed parallel to the reference axis on to the reflecting surface so that the reflected beam sweeps out a conical surface, and an adjustable iris shutter 28 is provided for masking the outer portion of the annular path of the beam together with a photo-sensitive member 34 responsive to changes in masking arising from the angular displacement. The arrangement is applied to a cryogenic gyroscope 10 in a gymbal mounted housing 12 the axis of which is maintained in alignment with the axis of the gyroscope by torquers controlled by the sensed displacement signal. The light from a lamp 16 is focused by a lens 18 on a pinhole reticule 20 and provides the beam e, f, through a two-prism beam splitter 22 and a lens 26. The iris is disposed in a plane spaced from lens 26 the same optical distance as the pinhole, and the partly masked beam Q rotating around the edge of the iris is rendered stationary on photo-sensitive tube 34 by lens 32. A pulsatance developed by misalignment is demodulated in 36 by mixing with the output of an oscillator 44 the frequency of which is locked by a second beam from the beam splitter which rotates around the periphery of a lens 40 and falls on a photo-cell 42, the lens having a radial line 46 which interrupts the light each revolution. |
