Intensity modulation type optical sensor and optical...

Details Intensity modulation type optical sensor and optical... Intensity modulation type optical sensor and optical...

2006-03-01

2010-02-02

Lee, John R (Department: 2878)

Radiant energy

Photocells; circuits and apparatus

Optical or pre-photocell system

C250S227170, C250S227210, C324S096000, C356S365000

Reexamination Certificate

active

07655900

ABSTRACT:
An influence on a sensor output is suppressed to a minimum degree even in the case when there is a ripple in a light source, thereby improving the measurement accuracy. In an intensity modulation type optical sensor, light from a light source1is guided to a sensor head6, the intensity of the light is modulated on the basis of an alternating current (AC) measured object (for example, a current i) changing with time, the modulated light is received in a light receiving element81and converted into an electrical signal, and a normalized received signal Xs indicating a degree of modulation is acquired from a ratio of an AC component As and a DC component Ds of the electrical signal to thereby acquiring a value of the AC measured object. Further in this invention, a reference signal Vr is acquired by separating and receiving part of light incident on the sensor head6, a normalized reference signal Xr is acquired from a ratio of an AC component Ar and a DC component Dr of the reference signal, and the normalized reference signal Xr is subtracted from the normalized received signal Xs, thereby reducing noises and improving the accuracy.

REFERENCES:
patent: 3629703 (1971-12-01), Bernard
patent: 3707329 (1972-12-01), Jaecklin et al.
patent: 4112367 (1978-09-01), Hepner et al.
patent: 4564754 (1986-01-01), Sato et al.
patent: 4694243 (1987-09-01), Miller et al.
patent: 4725140 (1988-02-01), Musha
patent: 4797607 (1989-01-01), Dupraz
patent: 4916387 (1990-04-01), Miller
patent: 5063290 (1991-11-01), Kersey
patent: 5125744 (1992-06-01), Watanabe
patent: 5136235 (1992-08-01), Brandle et al.
patent: 5363363 (1994-11-01), Gage
patent: 5491682 (1996-02-01), Dohmeier et al.
patent: 5656934 (1997-08-01), Bosselmann
patent: 5764046 (1998-06-01), Bosselmann
patent: 5811964 (1998-09-01), Bosselmann et al.
patent: 5834933 (1998-11-01), Meier
patent: 5847560 (1998-12-01), Bosselmann et al.
patent: 5895912 (1999-04-01), Bosselmann et al.
patent: 6114846 (2000-09-01), Bosselmann et al.
patent: 6122415 (2000-09-01), Blake
patent: 6140634 (2000-10-01), Bosselmann
patent: 6154022 (2000-11-01), Willsch et al.
patent: 6208129 (2001-03-01), Willsch et al.
patent: 6417660 (2002-07-01), Menke
patent: 6479979 (2002-11-01), Kingsley et al.
patent: 6495999 (2002-12-01), Beierl et al.
patent: 6504355 (2003-01-01), Minier
patent: 6563589 (2003-05-01), Bennett et al.
patent: 6618153 (2003-09-01), Lin et al.
patent: 6630819 (2003-10-01), Lanagan et al.
patent: 6724179 (2004-04-01), Kingsley et al.
patent: 6946827 (2005-09-01), Rahmatian et al.
patent: 6952107 (2005-10-01), Rahmatian
patent: 2002/0000801 (2002-01-01), Menke
patent: 2002/0011831 (2002-01-01), Minier
patent: 2002/0145414 (2002-10-01), Lanagan et al.
patent: 2003/0042884 (2003-03-01), Kingsley et al.
patent: 2003/0117125 (2003-06-01), Rahmatian et al.
patent: 2003/0117126 (2003-06-01), Rahmatian
patent: 2009/0090842 (2009-04-01), Kurosawa et al.
patent: 58-139082 (1983-08-01), None
patent: 59-061783 (1984-04-01), None
patent: 64-088373 (1989-04-01), None
patent: 3-282383 (1991-12-01), None
patent: 11-264766 (1999-09-01), None
patent: 2000-266787 (2000-09-01), None
International Search Report by Japanese Patent Office dated May 23, 2006.
Technical data on optical fiber sensor: revised edition, edited by Toshihiko Yoshino, 1986, pp. 404-405.
Kiyoshi Kurosawa, “Development of Optical Fiber Current Sensors and Their Applications”, Journal of the Institute of Electrostatics Japan, vol. 28 No. 5, 2004, pp. 251-257.
M. Takahashi et al. “Sagnac Interferometer-type fiber-optic current sensor using single-mode fiber down leads”, Technical Digest of 16thInternational conference on optical fiber sensor, 2003, pp. 756-759.
Kiyoshi Kurosawa, “Investigation on Basic Characteristics of Optical Current Transducer Applying Optical Heterodyning Technique”, The institute of Electrical Engineers of Japan, Transactions on Power and Energy, vol. B 117, No. 3, 1997, pp. 354-363.

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