US3790883A
Expired / Lapsed
US
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Particle study apparatus having improved particle resolution means
Assignee: Coulter Electronics Inc
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Filing: 1972-05-09
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Granted: 1974-02-05
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Expires: 1992-05-09
Abstract
Abstract Electronic particle study apparatus of the Coulter type having a sensing zone arrangement wherein pulses are generated by particles in liquid suspension passing through the scanning ambit of a minute scanning aperture of said arrangement. Particle resolution means are provided which includes a low threshold level detector circuit, a high threshold level detector circuit, and a positive slope detector circuit including a differentiating circuit. The output signals from the detector circuits are fed through a logic circuit to a counter circuit so that each positive slope end of each pulse whose amplitude is between the low threshold and high threshold enables a signal in the form of a trigger pulse to be fed to the counting circuit to register a count signal representative of the passage of a particle through the scanning ambit of the scanning aperture to enable resolution or distinguishment between two particles following each other at a short time interval therebetween.
Inventors
- 👤 P Bergegere
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:22
CPC Classifications
G; G01; G01N; G01N15/00; G01N15/10; G01N15/1031; G01N15/12; G01N15/131; G01N15/132
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
180 words
Particle study apparatus of the type including a sensing zone arrangement wherein a train of pulses is generated representative of particles passing through the scanning ambit within said sensing zone, means for enhancing the resolving of pulses of said pulse train which are representative of particles passing through said scanning ambit with a short time interval between passing particles, said resolving means comprising: a pair of threshold level circuits coupled to operate upon the pulses generated by said sensing zone arrangement and to provide an output signal for each pulse having a maximum amplitude lying between predetermined maximum and minimum values, a positive slope detector means connected in parallel with said threshold level circuits to provide an output signal in response to each positive slope of each pulse, and logic circuit means electrically coupled to said threshold circuits and said positive slope detector means to receive said output signals respectively therefrom and responsive to said output signals for generating an output for each positive slope end occurring when the amplitude of each pulse is between said maximum and minimum values.
Claim 2
Dependent Claim
180 words
Particle study apparatus of the type including a sensing zone arrangement wherein a train of pulses is generated representative of particles passing through the scanning ambit within said sensing zone, means for enhancing the resolving of pulses of said pulse train which are representative of particles passing through said scanning ambit with a short time interval between passing particles, said resolving means comprising: a pair of threshold level circuits coupled to operate upon the pulses generated by said sensing zone arrangement and to provide an output signal for each pulse having a maximum amplitude lying between predetermined maximum and minimum values, a positive slope detector means connected in parallel with said threshold level circuits to provide an output signal in response to each positive slope of each pulse, and logic circuit means electrically coupled to said threshold circuits and said positive slope detector means to receive said output signals respectively therefrom and responsive to said output signals for generating an output for each positive slope end occurring when the amplitude of each pulse is between said maximum and minimum values.
Claim 3
Dependent Claim
18 words
The apparatus as claimed in claim 1 in which the logic circuit means comprises a veto AND gate.
Claim 4
Dependent Claim
27 words
The apparatus as claimed in claim 1 in which the logic circuit is connected to a counter circuit, said counter circuit being activated by each output therefrom.
Claim 5
Dependent Claim
18 words
The apparatus as claimed in claim 1 in which said positive slope detector means comprises a differentiator circuit.
Claim 6
Dependent Claim
18 words
The apparatus as claimed in claim 1 in which said positive slope detector means comprises an RC circuit.
Claim 7
Dependent Claim
23 words
The apparatus as claimed in claim 5 in which said RC circuit is connected to an operational amplifier having a negative feedback diode.
Claim 8
Dependent Claim
48 words
The apparatus as claimed in claim 6 in which there is provided a shaper circuit and the output of said operational amplifier is connected to the input of said shaper circuit, the output of said shaper circuit being in the form of a signal having a rectangular waveshape.
Claim 9
Dependent Claim
19 words
The apparatus as claimed in claim 1 in which at least one of said threshold level circuits is adjustable.
Claim 10
Dependent Claim
17 words
The apparatus as claimed in claim 1 in which said threshold level detector circuits are each adjustable.
Claim 11
Dependent Claim
163 words
Particle study apparatus of the type including a sensing zone arrangement wherein a train of pulses is generated representative of particles passing through the scanning ambit within said sensing zone, means for enhancing the resolving of pulses of the said pulse train which are representative of particles passing through said scanning ambit with a short time interval between passing particles, said resolving means comprising: threshold level detector means for detecting the amplitude of each pulse in said pulse train and providing a first signal representing each pulse having a maximum amplitude beLow a certain maximum value, positive slope detector means for providing a second signal representative of the time of the end of each positive slope of each pulse, and logic circuit means connected to said threshold level detector means and said positive slope detector means to receive said first and second signals and to provide a logic output signal on each occasion when the positive slope end occurs during the first signal.
Claim 12
Dependent Claim
163 words
Particle study apparatus of the type including a sensing zone arrangement wherein a train of pulses is generated representative of particles passing through the scanning ambit within said sensing zone, means for enhancing the resolving of pulses of the said pulse train which are representative of particles passing through said scanning ambit with a short time interval between passing particles, said resolving means comprising: threshold level detector means for detecting the amplitude of each pulse in said pulse train and providing a first signal representing each pulse having a maximum amplitude beLow a certain maximum value, positive slope detector means for providing a second signal representative of the time of the end of each positive slope of each pulse, and logic circuit means connected to said threshold level detector means and said positive slope detector means to receive said first and second signals and to provide a logic output signal on each occasion when the positive slope end occurs during the first signal.
Claim 13
Dependent Claim
28 words
The apparatus as claimed in claim 10 in which said positive slope detector means comprises an RC circuit in series with an operational amplifier having negative feedback means.
Claim 14
Dependent Claim
70 words
The apparatus as claimed in claim 11 and a shaper circuit connected to the output of said operational amplifier, said shaper circuit providing an output signal in the form of a rectangular wave, said output signal being fed to said logic circuit along with said first signal from said threshold level detector means, whereupon said logic circuit provides an output indicating reception of both said first and second output signals.
Claim 15
Dependent Claim
36 words
The apparatus as claimed in claim 12 and a counter circuit connected to said logic circuit and adapted to be activated upon receipt of said logic circuit output signal so as to register each such occurrence.
Claim 16
Dependent Claim
15 words
Apparatus according to claim 10 in which said sensing zone includes a Coulter-type scanning aperture.
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) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |