Patent US3714829A successfully refreshed from Google Patents.
US3714829A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure measuring system
Assignee: Beckman Coulter Inc
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Filing: 1970-06-29
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Granted: 1973-02-06
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Expires: 1990-06-29
Abstract
Abstract A pressure measuring system including a light source and a pressure sensitive membrane illuminated by the light source and adapted to reflect the light in a manner dependent upon the pressure being sensed. A sensor is illuminated by the reflected light and includes a photosensitive detector connected in a Wheatstone bridge circuit lacking diagonal bilateral symmetry.
Inventors
- 👤 P Gilbert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:03
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0041; G01L9/0076; G01L9/0077
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
108 words
A pressure measuring system including pressure sensitive, reflective membrane means, a light source illuminating said membrane means, means defining a chamber and having at least one open end, the membrane means being supported by the means defining a chamber and closing an open end thereof, whereby changes in fluid pressure within the chamber alter the shape of the membrane thereby varying the amount of reflected light, and sensor means for detecting varying amounts of reflected light received from said membrane means in response to altered shape of said membrane means, said sensor means including at least two photosensitive detectors connected in a bridge circuit exhibiting diagonal bilateral asymmetry.
Claim 2
Dependent Claim
108 words
A pressure measuring system including pressure sensitive, reflective membrane means, a light source illuminating said membrane means, means defining a chamber and having at least one open end, the membrane means being supported by the means defining a chamber and closing an open end thereof, whereby changes in fluid pressure within the chamber alter the shape of the membrane thereby varying the amount of reflected light, and sensor means for detecting varying amounts of reflected light received from said membrane means in response to altered shape of said membrane means, said sensor means including at least two photosensitive detectors connected in a bridge circuit exhibiting diagonal bilateral asymmetry.
Claim 3
Dependent Claim
108 words
A pressure measuring system including pressure sensitive, reflective membrane means, a light source illuminating said membrane means, means defining a chamber and having at least one open end, the membrane means being supported by the means defining a chamber and closing an open end thereof, whereby changes in fluid pressure within the chamber alter the shape of the membrane thereby varying the amount of reflected light, and sensor means for detecting varying amounts of reflected light received from said membrane means in response to altered shape of said membrane means, said sensor means including at least two photosensitive detectors connected in a bridge circuit exhibiting diagonal bilateral asymmetry.
Claim 4
Dependent Claim
108 words
A pressure measuring system including pressure sensitive, reflective membrane means, a light source illuminating said membrane means, means defining a chamber and having at least one open end, the membrane means being supported by the means defining a chamber and closing an open end thereof, whereby changes in fluid pressure within the chamber alter the shape of the membrane thereby varying the amount of reflected light, and sensor means for detecting varying amounts of reflected light received from said membrane means in response to altered shape of said membrane means, said sensor means including at least two photosensitive detectors connected in a bridge circuit exhibiting diagonal bilateral asymmetry.
Claim 5
Dependent Claim
60 words
The pressure measuring system of claim 1 wherein said two photosensitive detectors are positioned with respect to said membrane means so that the bridge normally can be balanced only when it is asymmetrically illuminated whereby the sensor exhibits a greater response to a change in illumination from an unfocused light reflection than a sensor containing a diagonally bilaterally symmetric bridge.
Claim 6
Dependent Claim
20 words
The pressure measuring system of claim 2 wherein unequal areas of the photosensitive detectors are exposed to the reflected light.
Claim 7
Dependent Claim
35 words
The pressure measuring system of claim 3 including a mask blocking part of the surface area of one of the photosensitive detectors whereby unequal areas of the photosensitive detectors are exposed to the reflected light.
Claim 8
Dependent Claim
26 words
The pressure measuring system of claim 4 wherein the mask is shaped to follow a line of constant illumination on the surface of the photosensitive detector.
Claim 9
Dependent Claim
15 words
The pressure measuring system of claim 2 wherein the photosensitive detectors are of unequal sensitivity.
Claim 10
Dependent Claim
28 words
The pressure measuring system of claim 2 wherein one photosensitive detector is shielded from light reflected from the membrane means and exposed to light from the light source.
Claim 11
Dependent Claim
21 words
The pressure measuring system of claim 5 including means for reflecting light from the light source to the shielded photosensitive detector.
Claim 12
Dependent Claim
21 words
The pressure measuring system of claim 7 including means for controlling the amount of light received by the shielded photosensitive detector.
Claim 13
Dependent Claim
47 words
The pressure measuring system of claim 2 including four photosensitive detectors, each connected in a separate arm of the bridge and positioned proximate said membrane means so that the change of illumination with change of pressure being sensed is not the same on all four photosensitive detectors.
Claim 14
Dependent Claim
41 words
The pressure measuring system of claim 10 wherein the photosensitive detectors are arranged in two groups, the detectors in each group being from opposite sides of the bridge and unequal areas of the two groups are exposed to the reflected light.
Claim 15
Dependent Claim
35 words
The pressure measuring system of claim 11 including a mask blocking part of the surface area of one of the photosensitive detectors whereby unequal areas of the photosensitive detectors are exposed to the reflected light.
Claim 16
Dependent Claim
26 words
The pressure measuring system of claim 12 wherein the mask is shaped to follow a line of constant illumination on the surface of the photosensitive detector.
Claim 17
Dependent Claim
35 words
The pressure measuring system of claim 10 wherein the photosensitive detectors are arranged in two groups and one group is shielded from light reflected from the membrane and exposed to light from the light source.
Claim 18
Dependent Claim
23 words
The pressure measuring system of claim 14 including means for reflecting light from the light source to the shielded group of photosensitive detectors.
Claim 19
Dependent Claim
23 words
The pressure measuring system of claim 14 including means for controlling the amount of light received by the shielded group of photosensitive detectors.
Claim 20
Dependent Claim
23 words
The pressure measuring system of claim 14 wherein unequal areas of the photosensitive detectors in the shielded group arE exposed to the light.
Claim 21
Dependent Claim
63 words
The pressure measuring system of claim 14 including: a. a fifth photosensitive detector connected with one of the photosensitive detectors and shielded from light reflected from the membrane and exposed to light from the light source; and b. means for controlling the amount of light received by the fifth photosensitive detector so that variations in brightness of the source light can be compensated.
Claim 22
Dependent Claim
26 words
The pressure measuring system of claim 10 wherein the photosensitive detectors are arranged in two groups, the photosensitive detectors in each group being of unequal sensitivity.
Claim 23
Dependent Claim
18 words
The pressure measuring system of claim 2 including means for splitting the reflected light between the photosensitive detectors.
Claim 24
Dependent Claim
17 words
The pressure measuring system of claim 20 wherein the splitting means is a wedge shaped double mirror.
Claim 25
Dependent Claim
24 words
The pressure measuring system of claim 2 wherein two adjacent arms of the bridge do not contain photosensitive detectors and are unequal in impedance.
Claim 26
Dependent Claim
19 words
The pressure measuring system of claim 1 wherein the photosensitive detectors are connected in opposite arms of the bridge.
Claim 27
Dependent Claim
28 words
The pressure measuring system of claim 23 wherein the change of illumination with change of pressure being sensed is in the same direction on the two photosensitive detectors.
Claim 28
Dependent Claim
43 words
The pressure measuring system of claim 1 including four photosensitive detectors, each connected in a separate arm of the bridge and arranged so that the change of illumination with change of pressure being sensed is not the same on all four photosensitive detectors.
Claim 29
Dependent Claim
36 words
The pressure measuring system of claim 25 wherein the photosensitive detectors are arranged in two groups, and one group is shielded from light reflected from the membrane means and exposed to light from the light source.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |