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US4662225A Expired / Lapsed US ⏱️ 0.0 years remaining

Seismic detector

Assignee: Fujitec Co Ltd
•
Filing: 1985-04-30
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Granted: 1987-05-05
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Expires: 2005-04-30
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Abstract

Abstract The disclosure is directed to an improved a seismic detector comprising: a container for containing liquid therein, liquid means being contained in the bottom of the container, a source of light for illuminating the inside of the container, a sensor means having at least one photoelectric device for transforming the light inside the container into electric signals, and a signal processor means for generating an output when the output of the sensor means exceeds a predetermined value.

Inventors

  • 👤 Hiroshi Koh
  • 👤 Takashi Tokuyama

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 19:10
CPC Classifications
G; G01; G01V; G01V1/00; G01V1/16; G01V1/18; G01V1/181; G01H; G01H9/00

Claims Analysis

Total Claims: 27
Claim 1
Independent Claim 151 words
A seismic detector comprising: a cylindrical container having an interior sealed off from all external lights, said container having an interior bottom of a cone-like shape; a liquid means contained in the bottom of the container; a source of light for illuminating the inside of the container, arranged above the liquid means in the container; a photoelectric sensor means, arranged above the liquid means in the container, for receiving the light reflected from the surface of the liquid means by the light emitted from the source of light and for transforming the amount of light received into an electric signal in order to detect the vibrations of the liquid means as a change in the amount of the light received; and a signal processor means for generating an output signal when the output signal of the photoelectric sensor means exceeds a predetermined value to provide an indication of a seismic event.
Claim 2
Dependent Claim 151 words
A seismic detector comprising: a cylindrical container having an interior sealed off from all external lights, said container having an interior bottom of a cone-like shape; a liquid means contained in the bottom of the container; a source of light for illuminating the inside of the container, arranged above the liquid means in the container; a photoelectric sensor means, arranged above the liquid means in the container, for receiving the light reflected from the surface of the liquid means by the light emitted from the source of light and for transforming the amount of light received into an electric signal in order to detect the vibrations of the liquid means as a change in the amount of the light received; and a signal processor means for generating an output signal when the output signal of the photoelectric sensor means exceeds a predetermined value to provide an indication of a seismic event.
Claim 3
Dependent Claim 13 words
A seismic detector according to claim 1, wherein said liquid means is mercury.
Claim 4
Dependent Claim 13 words
A seismic detector according to claim 1, wherein said liquid means is oil.
Claim 5
Dependent Claim 22 words
A seismic detector according to claim 1, wherein the cone-like bottom of said container has an apex angle between 80° and 120°.
Claim 6
Dependent Claim 14 words
A seismic detector according to claim 1, wherein said apex angle is about 100°.
Claim 7
Dependent Claim 41 words
A seismic detector according to claim 1, wherein said signal processor means have one or more comparator means each of which compares the output signal of the photoelectric sensor means with a predetermined value different from that of other comparator means.
Claim 8
Dependent Claim 25 words
A seismic detector according to claim 1, wherein said source of light and said photoelectric device are arranged along the central axis of said container.
Claim 9
Dependent Claim 49 words
A seismic detector according to claim 1, wherein said signal processor means has an AC amplifier means which can provide an indication of the slope of the surface of the liquid means as a change in the amount of the light reflected from the surface of the liquid means.
Claim 10
Dependent Claim 40 words
A seismic detector according to claim 1, wherein said signal processor means includes a correction means which corrects the sensitivity of the detection of the light according to the DC component of said electric signal of said photoelectric sensor means.
Claim 11
Dependent Claim 39 words
A seismic detector according to claim 9, wherein said correction means is a means for varying an electric voltage supplied to said source of light according to the DC component of said electric signal of said photoelectric sensor means.
Claim 12
Dependent Claim 36 words
A seismic detector according to claim 9, wherein said correction means is a means for varying the gain of said AC amplifier according to the DC component of said electric signal of said photoelectric sensor means.
Claim 13
Dependent Claim 153 words
A seismic detector comprising: a cylindrical container having an interior sealed off from all external lights, said container having an interior bottom of a cone-like shape; a liquid means contained in the bottom of the container, the liquid means including two liquids of a different kind; a source of light for illuminating the inside of the container, arranged above the liquid means in the container; a photoelectric sensor means, arranged above the liquid means in the container, for receiving the light reflected from the surface of the liquid means by the light emitted from the source of light and for transforming the amount of light received into an electric signal in order to detect the vibrations of the liquid means as a change in the amount of the light received; and a signal processor means for generating an output signal when the output signal of the photoelectric sensor means exceeds a predetermined value.
Claim 14
Dependent Claim 153 words
A seismic detector comprising: a cylindrical container having an interior sealed off from all external lights, said container having an interior bottom of a cone-like shape; a liquid means contained in the bottom of the container, the liquid means including two liquids of a different kind; a source of light for illuminating the inside of the container, arranged above the liquid means in the container; a photoelectric sensor means, arranged above the liquid means in the container, for receiving the light reflected from the surface of the liquid means by the light emitted from the source of light and for transforming the amount of light received into an electric signal in order to detect the vibrations of the liquid means as a change in the amount of the light received; and a signal processor means for generating an output signal when the output signal of the photoelectric sensor means exceeds a predetermined value.
Claim 15
Dependent Claim 35 words
A seismic detector according to claim 12, wherein one of said liquids is a first liquid which does not transmit or absorb the light and has a high reflectivity at the surface of the liquid.
Claim 16
Dependent Claim 15 words
A seismic detector according to claim 13, wherein one component of said liquids is mercury.
Claim 17
Dependent Claim 15 words
A seismic detector according to claim 12, wherein one component of said liquids is mercury.
Claim 18
Dependent Claim 25 words
A seismic detector according to claim 12, wherein one of said liquids is a second liquid which can dampen the motion of the first liquid.
Claim 19
Dependent Claim 13 words
A seismic detector according to claim 16, wherein the second liquid is oil.
Claim 20
Dependent Claim 22 words
A seismic detector according to claim 12, wherein the cone-like bottom of said container has an apex angle between 80° and 120°.
Claim 21
Dependent Claim 14 words
A seismic detector according to claim 18, wherein said apex angle is about 100°.
Claim 22
Dependent Claim 41 words
A seismic detector according to claim 12, wherein said signal processor means have one or more comparator means each of which compares the output signal of the photoelectric sensor means with a predetermined value different from that of other comparator means.
Claim 23
Dependent Claim 25 words
A seismic detector according to claim 12, wherein said source of light and said photoelectric device are arranged along the central axis of said container.
Claim 24
Dependent Claim 46 words
A seismic detector according to claim 12, wherein said signal processor means has an AC amplifier means which can give the slope of the surface of the liquid means as a change in the amount of the light reflected from the surface of the liquid means.
Claim 25
Dependent Claim 40 words
A seismic detector according to claim 12, wherein said signal processor means includes a correction means which corrects the sensitivity of the detection of the light according to the DC component of said electric signal of said photoelectric sensor means.
Claim 26
Dependent Claim 39 words
A seismic detector according to claim 23, wherein said correction means is a means for varying an electric voltage supplied to said source of light according to the DC component of said electric signal of said photoelectric sensor means.
Claim 27
Dependent Claim 35 words
A seismic detector according to claim 23, wherein said correction means is a means for varying the gain of said AC amplifier according to DC component of said electric signal of said photoelectric sensor means.

References Cited (Backward Citations)

US31248A Cited
US4083255A Cited
USRE31248E Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-05-04 1990-11-03 1991-05-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-05-04 1994-11-03 1995-05-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-05-04 1998-11-03 1999-05-05 $7700.00 Window Closed / Lapsed

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