US3582659A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spectrophotometer circuit with linear response to absorbance
Assignee: Individual
•
Filing: 1969-06-17
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Granted: 1971-06-01
•
Expires: 1989-06-17
Abstract
Abstract This photometer employs a network of negatively biased diodes to compensate for the nonlinear characteristics of its solid-state photodetector and detector circuit, and thereby linearize its electrical response with respect to absorbance. The instrument features an integrated, fixed-geometry cuvette holder, light aperture, monochromatic filter, photodetector, and incubator block with continuous electronic temperature control capability. Calibration is accomplished by varying the light intensity by means of a highly stable, finely adjustable variable lamp power supply.
Inventors
- 👤 Manuel S Dekker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:16
CPC Classifications
G; G06; G06G; G06G7/00; G06G7/12; G06G7/26; G06G7/28; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/251; G01N21/253; G01N21/27
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
119 words
A spectrophotometer circuit comprising: a power source, a photodetector and a sensitive current measuring device connected in parallel in a first circuit; and a linearizing circuit including a biasing resistor shunted across said current measuring device, said linearizing circuit being connected witH said first circuit for linearizing the response of said first circuit with respect to the absorbance of a sample of a phototransmissive material, said linearizing circuit comprising a plurality of diodes connected in parallel with said biasing resistor and means for selectively biasing said diodes to compensate for nonlinearity in said first circuit over a discrete portion of its response curve, thereby selectively altering the output of said photodetector and the input to said current measuring device.
Claim 2
Dependent Claim
119 words
A spectrophotometer circuit comprising: a power source, a photodetector and a sensitive current measuring device connected in parallel in a first circuit; and a linearizing circuit including a biasing resistor shunted across said current measuring device, said linearizing circuit being connected witH said first circuit for linearizing the response of said first circuit with respect to the absorbance of a sample of a phototransmissive material, said linearizing circuit comprising a plurality of diodes connected in parallel with said biasing resistor and means for selectively biasing said diodes to compensate for nonlinearity in said first circuit over a discrete portion of its response curve, thereby selectively altering the output of said photodetector and the input to said current measuring device.
Claim 3
Dependent Claim
34 words
The spectrophotometer circuit of claim 1 in which said biasing means include a pair of parallel biasing resistors in series with each of said diodes, one of said biasing resistors being a variable resistor.
Claim 4
Dependent Claim
25 words
The spectrophotometer circuit of claim 2 comprising in addition means associated with said first circuit for selectively varying the gain of said current measuring device.
Claim 5
Dependent Claim
28 words
The spectrophotometer circuit of claim 3 in which said means for varying the gain of said current measuring device include a variable resistor shunting said current measuring device.
Claim 6
Dependent Claim
26 words
The spectrophotometer circuit of claim 4 including in addition means associated with said first circuit for selectively switching the effective range of said current measuring device.
Claim 7
Dependent Claim
18 words
The spectrophotometer circuit of claim 1 in which said photodetector is connected in series with said linearizing circuit.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-05-31 | 1974-11-30 | 1975-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-31 | 1978-11-30 | 1979-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-31 | 1982-11-30 | 1983-06-01 | $7700.00 | Window Closed / Lapsed |