Patent US3943381A successfully refreshed from Google Patents.
US3943381A
Expired / Lapsed
US
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Pulse generating apparatus having a chattering pulse elimination circuit
Assignee: Canon Inc
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Filing: 1973-09-04
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Granted: 1976-03-09
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Expires: 1993-09-04
Abstract
Abstract A pulse generating apparatus which generates rectangular wave signal by opening and closing of a mechanical contact and has a differentiation circuit to output such pulse signal as corresponding to the rising position of said signal. Said apparatus has a rectangular wave generating means to generate rectangular wave signal by opening and closing a mechanical contact, a differentiation circuit to receive the rectangular wave signal from said rectangular wave generating means and to differentiate the same, and a high impedance element connected to the discharge circuit within said differentiation circuit. By this the discharging time constant factor of the differentiation circuit becomes large, sharply reducing the chattering pulse which parasitises to the rectangular wave signal.
Inventors
- 👤 Masanori Uchidoi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:00
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/01; H03K3/013
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
131 words
An apparatus for transmitting the movement of a switch from one position to another between one circuit containing the switch and another circuit, said switch having an expected rate of contact bounce, comprising a capacitance, circuit means for connecting said capacitance in series between the one circuit and the other, characterized in that said circuit means includes means for charging said capacitance to a voltage appearing at the switch at a rate at least as fast as the expected contact bounce when the switch assumes one of its positions and for discharging said capacitance at a rate substantially slower than the contact bounce when the switch assumes its other position, said means in said circuit including a unidirectional current carrying member connected in series between the one circuit and the capacitance.
Claim 2
Independent Claim
131 words
An apparatus for transmitting the movement of a switch from one position to another between one circuit containing the switch and another circuit, said switch having an expected rate of contact bounce, comprising a capacitance, circuit means for connecting said capacitance in series between the one circuit and the other, characterized in that said circuit means includes means for charging said capacitance to a voltage appearing at the switch at a rate at least as fast as the expected contact bounce when the switch assumes one of its positions and for discharging said capacitance at a rate substantially slower than the contact bounce when the switch assumes its other position, said means in said circuit including a unidirectional current carrying member connected in series between the one circuit and the capacitance.
Claim 3
Dependent Claim
13 words
An apparatus as in claim 1, wherein said unidirectional member is a diode.
Claim 4
Dependent Claim
24 words
An apparatus as in claim 2, wherein said diode is poled for easy current flow to said capacitance when the switch means is closed.
Claim 5
Dependent Claim
44 words
An apparatus as in claim 1, wherein said means in said circuit means includes a resistance shunting the other portion of the circuit and having a value sufficiently small to allow charging of the capacitance at a rate faster than the contact bounce rate.
Claim 6
Dependent Claim
131 words
A pulse generating apparatus for eliminating contact bounce noise generated by connecting and disconnecting a contact switch and having characteristic repetition times, comprising; a. differentiating circuit means having an output terminal and at least one capacitor to receive said contact bounce noise; b. electrical means connecting said differentiating circuit means to said contact switch so as to actuate said differentiating circuit means in response to the connection of said contact switch, and c. impedance means in said electrical means and connected to said differentiating circuit means for forming a discharge path for the capacitor in said differentiating circuit means, said impedance means having a sufficiently high resistance so that said impedance means and said capacitor produce a long time constant substantially longer than the repetition times of the contact bounce noise.
Claim 7
Dependent Claim
131 words
A pulse generating apparatus for eliminating contact bounce noise generated by connecting and disconnecting a contact switch and having characteristic repetition times, comprising; a. differentiating circuit means having an output terminal and at least one capacitor to receive said contact bounce noise; b. electrical means connecting said differentiating circuit means to said contact switch so as to actuate said differentiating circuit means in response to the connection of said contact switch, and c. impedance means in said electrical means and connected to said differentiating circuit means for forming a discharge path for the capacitor in said differentiating circuit means, said impedance means having a sufficiently high resistance so that said impedance means and said capacitor produce a long time constant substantially longer than the repetition times of the contact bounce noise.
Claim 8
Dependent Claim
19 words
A pulse generating apparatus according to claim 5, wherein the impedance means is shunted across said differentiating circuit means.
Claim 9
Dependent Claim
38 words
A pulse generating apparatus according to claim 5, wherein said differentiating circuit means comprises a capacitor and a resistor electrically connected in series, said capacitor being operatively coupleable to the electrical power supply means by said contact switch.
Claim 10
Dependent Claim
26 words
A pulse generating apparatus according to claim 7, wherein the output terminal is electrically connected to said differentiating circuit means between said capacitor and said resistor.
Claim 11
Dependent Claim
18 words
A pulse generating apparatus according to claim 5, wherein said impedance means includes a resistor with high resistance.
Claim 12
Dependent Claim
26 words
An apparatus as in claim 9, wherein the time constant of said resistor and capacitor is longer than three times the repetition period of the noise.
Claim 13
Dependent Claim
120 words
A pulse generating apparatus for eliminating repetitive contact bounce noise generated by connecting and disconnecting a contact switch, comprising; a. a D.C. power supply means, b. voltage dividing resistance means connected with and disconnected from said D.C. power source by said contact switch, c. differentiating circuit having an output terminal and at least one capacitor coupled to respond to the bounce noise, and connected across said voltage dividing resistance means, and d. impedance means connected to said differentiating circuit and forming a discharge path for the capacitor in the differentiating circuit, said impedance means having high resistance which, with the capacitor in said differentiating circuit means, forms a time constant longer than the repetition period of the contact bounce noise.
Claim 14
Dependent Claim
120 words
A pulse generating apparatus for eliminating repetitive contact bounce noise generated by connecting and disconnecting a contact switch, comprising; a. a D.C. power supply means, b. voltage dividing resistance means connected with and disconnected from said D.C. power source by said contact switch, c. differentiating circuit having an output terminal and at least one capacitor coupled to respond to the bounce noise, and connected across said voltage dividing resistance means, and d. impedance means connected to said differentiating circuit and forming a discharge path for the capacitor in the differentiating circuit, said impedance means having high resistance which, with the capacitor in said differentiating circuit means, forms a time constant longer than the repetition period of the contact bounce noise.
Claim 15
Dependent Claim
45 words
A pulse generating apparatus according to claim 11, wherein further comprising a unidirectional current carrying member for connecting said differentiating circuit in parallel with said voltage dividing resistance means in such a manner that the capacitor in said differentiating circuit stores said contact bounce noise.
Claim 16
Dependent Claim
17 words
A pulse generating apparatus according to claim 12, wherein said unidirectional current carrying member comprises a diode.
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) | 1979-03-09 | 1979-09-08 | 1980-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-09 | 1983-09-08 | 1984-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-09 | 1987-09-08 | 1988-03-09 | $7700.00 | Window Closed / Lapsed |