US4816695A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical fluid detector
Assignee: Individual
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Filing: 1987-08-31
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Granted: 1989-03-28
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Expires: 2007-08-31
Abstract
Abstract An optical fluid detector (10) has an opaque housing (12). There is a first passage (14) through the housing (12) to receive a transparent, flexible plastic tube (50). A second passage (20) through the housing (12) orthogonally intersects the first passage (14). A first receptacle (22) in the housing has a light emitting diode (D1) with a housing having a flat surface (30) engaging the receptacle (22) and facing the second passage (20). A second receptacle (24) at a second end of the second passage on an opposing side of the first passage (14) from the first receptacle has a photodetector (Q1) with a housing having a flat surface (32) facing the second passage (20). An output circuit (33) is connected to the photodetector.
Inventors
- 👤 Thomas N. Lavin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:54
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/28; G01F23/284; G01F23/292; G01F23/2921
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
195 words
An optical fluid detector for determining the presence or absence of a liquid filling a tube, which comprises an opaque housing, a first passage through said housing dimensioned and configured to receive an at least semitransparent, flexible plastic tube which is filled with the liquid when the liquid is present, a second passage through said housing is present, a second passage through said housing orthogonally intersecting said first passage, a first receptacle in said housing at a first end of said second passage, a light emitting diode in said first receptacle having a flat surface facing said second passage and engaging a mating surface in said first receptacle, a second receptacle at a second end of said second passage on an opposing side of said first passage from said first receptacle, a photodetector in said second receptacle having a flat surface said second passage and having a flat surface facing said second passage and engaging a mating surface in said second receptacle, and an output circuit connected to said photodetector, said output circuit including means for establishing a time delay on a liquid to no liquid transition between said light emitting diode and said photodetector.
Claim 2
Dependent Claim
195 words
An optical fluid detector for determining the presence or absence of a liquid filling a tube, which comprises an opaque housing, a first passage through said housing dimensioned and configured to receive an at least semitransparent, flexible plastic tube which is filled with the liquid when the liquid is present, a second passage through said housing is present, a second passage through said housing orthogonally intersecting said first passage, a first receptacle in said housing at a first end of said second passage, a light emitting diode in said first receptacle having a flat surface facing said second passage and engaging a mating surface in said first receptacle, a second receptacle at a second end of said second passage on an opposing side of said first passage from said first receptacle, a photodetector in said second receptacle having a flat surface said second passage and having a flat surface facing said second passage and engaging a mating surface in said second receptacle, and an output circuit connected to said photodetector, said output circuit including means for establishing a time delay on a liquid to no liquid transition between said light emitting diode and said photodetector.
Claim 3
Dependent Claim
14 words
The optical fluid detector of claim 1 in which said photodetector comprises a phototransistor.
Claim 4
Dependent Claim
56 words
The optical fluid detector of claim 1 in which said output circuit comprises a detector circuit connected to said photodetector, said means for establishing a time delay in the form of a delay circuit connected to receive an output from said detector circuit, and a logic circuit connected to receive an output from said delay circuit.
Claim 5
Dependent Claim
40 words
The optical fluid detector of claim 3 in which said detector circuit comprises an operational amplifier having a first input terminal connected to receive an output signal from said photodetector and a second input terminal connected to a reference potential.
Claim 6
Dependent Claim
67 words
The optical fluid detector of claim 3 in which said logic circuit comprises a flip-flop circuit connected to receive the output from said time delay circuit, a first AND gate connected to receive an output from said flip-flop circuit, a second AND gate connected to receive an output from said first AND gate, and an OR gate connected to receive an output from said second AND gate.
Claim 7
Dependent Claim
68 words
The optical fluid detector of claim 1 in which said second passage has a first portion between the flat surface of the housing of said light emitting diode and said first passage and a second portion between the flat surface of the housing of said photodetector and said first passage, said first and second portions having a length greater than a cross section dimension of said second passage.
Claim 8
Dependent Claim
49 words
The optical fluid detector of claim 1 connected to a chromatography system, said optical fluid detector being electrically connected to provide signal inputs to a controller of said chromatography system, said controller being electrically connected and configured to control operation of said chromatography system based on the signal inputs.
Claim 9
Dependent Claim
24 words
The optical fluid detector and chromatography system of claim 7 additionally comprising at least one additional optical fluid detector connected to said chromatography system.
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) | 1992-03-27 | 1992-09-26 | 1993-03-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-27 | 1996-09-26 | 1997-03-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-27 | 2000-09-26 | 2001-03-28 | $7700.00 | Window Closed / Lapsed |