Title:
FREQUENCY SHIFTER AND OPTICAL DISPLACEMENT MEASURING EQUIPMENT USING THE SAME
Document Type and Number:
Japanese Patent JP3492024
Kind Code:
B2
Abstract:
PURPOSE: To detect information on the speed of a moving object with high accuracy by setting the period of an impression voltage and the thickness of an electrooptical element at values at which the resonance of the element is prevented.
CONSTITUTION: The thickness (d) of electrooptical elements 10a and 10b and a period TS of serrodyne driving thereof are set as follows. The elements 10a and 10b have a Pockels effect and also a piezoelectric effect. Shapes thereof are changed at the time of a fall of a sawtooth wave and the vibration thereof resonates with the period TS. The resonance becomes minimum and a high frequency decreases at the time of TS=2d/v×(n+1/2) when an acoustic velocity in the direction of voltage impression of the elements 10a and 10b is denoted by (v) and (n) is an integer. By selecting the driving period TS of the elements 10a and 10b in this way, a frequency shifter is made stable and highly accurate information on a speed is obtained.
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Inventors:
Shujiro Kadowaki
Makoto Takamiya
Makoto Takamiya
Application Number:
JP13589595A
Publication Date:
February 03, 2004
Filing Date:
May 09, 1995
Export Citation:
Assignee:
Canon Inc
International Classes:
G01P3/36; G01B11/00; G01P5/00; G01S17/58; (IPC1-7): G01S17/58; G01P3/36; G01P5/00
Domestic Patent References:
| JP5341043A | ||||
| JP2232620A | ||||
| JP5210072A | ||||
| JP4230885A | ||||
| JP2262064A | ||||
| JP6132032A | ||||
| JP515018U |
Attorney, Agent or Firm:
Yukio Takanashi