Title:
TIME INTERVAL MEASURING METHOD AND DISTANCE MEASURING DEVICE
Document Type and Number:
Japanese Patent JP3166664
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To eliminate the measurement abnormality resulted from a phase slippage and dispense with delay regulation by generating a plurality of series of sine waves in generation of a start event, measuring the phase angles of the sine waves in generation of a stop event, and determining the time difference between both the event generations on the basis of the difference between the measured phase angles.
SOLUTION: As means for generating reference sine waves of a plurality of series of sine waves having different frequencies fa and fb in a start event are provided frequency dividers 1a, 1b for resetting phases and dividing a reference signal having a frequency (f) in different dividing ratios. As means for measuring phase angles &phiv a, &phiv b of a plurality of series of reference sine waves having different frequencies fa, fb in a stop event are provided sample and hold circuits 2a, 2b and phase angle measuring instruments 4a, 4b. On the basis of the difference between the measured phase angles &phiv a, &phiv b, the time difference between both the event generations is determined by a time difference computer 7.
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Inventors:
Yoshikawa Shiro
Kazumi Sagawa
Kazumi Sagawa
Application Number:
JP18305597A
Publication Date:
May 14, 2001
Filing Date:
June 24, 1997
Export Citation:
Assignee:
NEC
International Classes:
G04F10/04; G01S13/16; G04F10/06; (IPC1-7): G04F10/06
Domestic Patent References:
| JP551518A | ||||
| JP5172962A | ||||
| JP5333169A | ||||
| JP8122465A |
Attorney, Agent or Firm:
Masahiro Fukuyama
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