Apparatus for detecting rotational speed
AssigneeRicoh Company, Ltd.
InventorsNobuo Iwata, Mitsugu Sugiyama, Toshiya Sato, Tadashi Shinohara, Yutaka Shio, Tomonori Yabuta
Life of this patent
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Abstract
An apparatus for a rotational speed detecting includes a rotating disc having plural slits in a circumferential direction. A radiant element radiates light rays through the slits. A photodetector receives the rays radiated by the radiant element. Peak detectors detects peak points of the detected signal and a calculator calculates a rotational speed. The photodetector include two photodetectors separated by a distance .DELTA.L.
Claims16
An apparatus for detecting a rotational speed of a rotating object, comprising:
- a rotating disc attached to an axis of the rotating object, the rotating disc including a plurality of slits;
- a radiant element radiating rays through the plurality of slits;
- first and second photodetecting elements separated by a predetermined distance .DELTA.L receiving the radiating rays radiated from the radiant element through the plurality of slits;
- and
- a calculator calculating a rotational speed of the rotating object based on signals output by the first and second photodetecting elements, wherein the calculator calculates the rotational speed by dividing the predetermined distance .DELTA.L separating the first and second photodetector elements by a time .DELTA.T required for the first and second photodetecting elements to detect radiating rays passing through a same slit.
An apparatus for detecting a rotational speed of a rotating object, comprising:
- rotating means attached to an axis of the rotating object, the rotating means including a plurality of slit means;
- radiating means for radiating rays through the plurality of slit means;
- first and second photodetecting means separated by a predetermined distance .DELTA.L for receiving the radiating rays radiated from the radiating means through the plurality of slit means;
- and
- calculating means for calculating a rotational speed of the rotating object based on signals output by the first and second photodetecting means, wherein the calculator means calculates the rotational speed by dividing the predetermined distance .DELTA.L separating the first and second photodetector means by a time .DELTA.T required for the first and second photodetecting means to detect radiating rays passing through a same slit means.
Dependencies are inferred from the claim text.