US3832577A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Threshold extraction circuitry for noisy electric waveforms
Assignee: International Business Machines Corp
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Filing: 1973-06-22
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Granted: 1974-08-27
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Expires: 1993-06-22
Abstract
Abstract Significant low frequency noise components in an electric wave, likely to follow larger transient components, are accommodated by automatically adjusting threshold crossing extraction circuitry. Peak component values of each cycle of a wave are stored and used in adjusting the threshold for the succeeding cycle of that wave. The peak level of each mark signal and that of each space signal component is stored by circuitry closely tracking the pertinent changes in the wave envelope. This circuitry is automatically adjusted rapidly at the beginning of each cycle and thus provides control of threshold adjustment without delay under widely varying conditions, such as are encountered in hand scanning of bar coding and the like. Facile circuitry comprises capacitive negative and positive peak tracking and storing circuits interconnected by a resistance divider network from which the threshold value is extracted for application to a signal comparator circuit in which the threshold signal is derived. Output of the comparator circuit is applied to the tracking circuits for arming them. The input signal is differentiated for enabling the tracking and storing circuits alternately in accordance with the sign of the signal wave slope. Reset circuitry is arranged for maintaining operation within the normal range.
Inventors
- 👤 J Harr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:59
CPC Classifications
G; G06; G06K; G06K7/00; G06K7/10; G06K7/10544; G06K7/10821; G06K7/10851
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
232 words
Threshold extraction circuitry for noisy electric waves, comprising input electric wave terminals, output electric waves terminals, a comparator circuit having input circuit terminals directly connected to said input electric wave terminals, further input circuit terminals and output circuit terminals connected to said output wave terminals, an electric state manifesting circuit for indicating peak positive states having input circuit terminals connected to said input electric wave terminals, control circuit terminals and having output circuit terminals, another electric state manifesting circuit for indicating negative states having input circuit terminals connected to said input wave terminals, control circuit terminals and having output circuit terminals, an algebraic summing circuit having complementary input circuit terminals connected individually to said output terminals of said positive and negative peak electric state manifesting circuits and having output terminals connected to said further input circuit terminals of said comparator circuit, and a control circuit having input circuit terminals coupled to said input electric wave terminals, other input circuit terminals connected to said output circuit terminals of said comparator circuit, and having output circuit terminals coupled to said control circuit terminals of said manifesting circuits, and arranged for decreasing the level of one of said manifesting circuits on a transition of given direction appearing at the output circuit terminals of said comparator circuit and for decreasing the level of the other of said manifesting circuits on a transition of the opposite direction.
Claim 2
Dependent Claim
232 words
Threshold extraction circuitry for noisy electric waves, comprising input electric wave terminals, output electric waves terminals, a comparator circuit having input circuit terminals directly connected to said input electric wave terminals, further input circuit terminals and output circuit terminals connected to said output wave terminals, an electric state manifesting circuit for indicating peak positive states having input circuit terminals connected to said input electric wave terminals, control circuit terminals and having output circuit terminals, another electric state manifesting circuit for indicating negative states having input circuit terminals connected to said input wave terminals, control circuit terminals and having output circuit terminals, an algebraic summing circuit having complementary input circuit terminals connected individually to said output terminals of said positive and negative peak electric state manifesting circuits and having output terminals connected to said further input circuit terminals of said comparator circuit, and a control circuit having input circuit terminals coupled to said input electric wave terminals, other input circuit terminals connected to said output circuit terminals of said comparator circuit, and having output circuit terminals coupled to said control circuit terminals of said manifesting circuits, and arranged for decreasing the level of one of said manifesting circuits on a transition of given direction appearing at the output circuit terminals of said comparator circuit and for decreasing the level of the other of said manifesting circuits on a transition of the opposite direction.
Claim 3
Dependent Claim
31 words
Threshold extraction circuitry as defined in claim 1 and wherein said control circuitry comprises a differentiating circuit coupled between said input electric wave terminals and said manifesting circuit input circuit terminals.
Claim 4
Dependent Claim
63 words
Threshold extraction circuitry as defined in claim 1 and wherein said control circuitry comprises a differentiating circuit coupled to said manifesting circuits by a comparing circuit having input circuit terminals connected to said differentiating circuit output terminals, reference input circuit terminals connected to a point of fixed reference potential, and output circuit terminals coupled to said control circuit terminals of said manifesting circuits.
Claim 5
Dependent Claim
27 words
Threshold extraction circuitry as defined in claim 1 and wherein said electric state manifesting circuits each are adjusted in a half cycle of said input electric wave.
Claim 6
Dependent Claim
51 words
Threshold extraction circuitry as defined in claim 3 and wherein said control circuitry comprises AND gating circuits having input leads connected individually to said comparing circuits, input leads connected to said output electric wave terminals and output leads connected individually to said input circuit terminals of said electric state manifesting circuits.
Claim 7
Dependent Claim
42 words
Threshold extraction circuitry as defined in claim 1 and incorporating a reset pulse generating circuit having input circuit terminals connected to said output electric wave terminals and output circuit terminals coupled to said control circuit terminals of said electric state manifesting circuits.
Claim 8
Dependent Claim
38 words
Threshold extraction circuitry as defined in claim 6 and wherein said reset pulse generating circuit coupling comprises OR gating circuits interposed between said differentiating circuit and said generating circuit and said control circuit terminals of said manifesting circuits.
Claim 9
Dependent Claim
17 words
Threshold extraction circuitry as defined in claim 1 and wherein said algebraic summing circuit comprises resistive elements.
Claim 10
Dependent Claim
19 words
Threshold extraction circuitry as defined in claim 8 and wherein said resistive elements are substantially equal in resistance value.
Claim 11
Dependent Claim
67 words
Threshold extraction circuitry as defined in claim 1 and wherein at least one of said electric state manifesting Circuits comprises a transistor having an input electrode connected to said input circuit terminals, a common electrode connected to said control circuit terminals and an output electrode connected to said output terminals, and an electric state manifesting component connected between said output electrode and a point of reference potential.
Claim 12
Dependent Claim
22 words
Threshold extraction circuitry as defined in claim 10 and incorporating a compensating component connected to said manifesting component at said output electrode.
Claim 13
Dependent Claim
21 words
Threshold extraction circuitry as defined in claim 10 and wherein said manifesting component is a capacitor for storing an electric charge.
Claim 14
Dependent Claim
21 words
Threshold extraction circuitry as defined in claim 10 and wherein said manifesting component is an inductor for maintaining an electric current.
Claim 15
Dependent Claim
17 words
Threshold extraction circuitry as defined in claim 10 and wherein said transistor is a field effect transistor.
Claim 16
Dependent Claim
29 words
Threshold extraction circuitry as defined in claim 4 and where the threshold level is developed in the first quarter cycle of each half cycle of said input electric wave.
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) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |