US3974419A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic flash apparatus with inhibition of contact bounce false triggering
Assignee: Rollei of America Inc
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Filing: 1975-05-27
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Granted: 1976-08-10
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Expires: 1995-05-27
Abstract
Abstract False triggering of the flash termination switch in a series termination electronic flash unit as a result of contact bounce is eliminated. Gating means inhibits the contacts from triggering the flash termination switch unless a voltage at a selected point in the circuit has attained a predetermined value. False triggering of the flash ignition as a result of noise present on the synchronization switch line is also inhibited.
Inventors
- 👤 James R. Adams, Jr.
- 👤 Dennis J. Wilwerding
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:50
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32; H05B41/325
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
124 words
In electronic flash apparatus including flash tube means for producing light; first switching means connected in series with the flash tube means, the first switching means having first and second main current carrying electrodes and a control electrode; second switching means having first and second main current carrying electrodes and a control electrode, the second switching means for triggering the flash tube means and the first switching means; the second switching means adapted to be connected to contact means for triggering the second switching means; the improvement comprising: gating means connected in series with the contact means and the second switching means for disenabling the contact means from triggering the second switching means unless a voltage at a selected point exceeds a predetermined value.
Claim 2
Dependent Claim
124 words
In electronic flash apparatus including flash tube means for producing light; first switching means connected in series with the flash tube means, the first switching means having first and second main current carrying electrodes and a control electrode; second switching means having first and second main current carrying electrodes and a control electrode, the second switching means for triggering the flash tube means and the first switching means; the second switching means adapted to be connected to contact means for triggering the second switching means; the improvement comprising: gating means connected in series with the contact means and the second switching means for disenabling the contact means from triggering the second switching means unless a voltage at a selected point exceeds a predetermined value.
Claim 3
Dependent Claim
25 words
The invention of claim 1 wherein the gating means comprises first zener diode means in series with the contact means and the second switching means.
Claim 4
Dependent Claim
18 words
The invention of claim 2 and further comprising resistor means in parallel with the first zener diode means.
Claim 5
Dependent Claim
24 words
The invention of claim 3 and further comprising second zener diode means in parallel with the contact means and the first zener diode means.
Claim 6
Dependent Claim
28 words
The invention of claim 2 and further comprising: capacitor means for supplying the current to trigger the first switching means; and charging means for charging the capacitor means.
Claim 7
Dependent Claim
21 words
The invention of claim 5 wherein the voltage at the selected point is determined by the voltage on the capacitor means.
Claim 8
Dependent Claim
42 words
The invention of claim 6 wherein the charging means has a charging time for charging the capacitor means whereby the time required for the voltage at the selected point to exceed the predetermined value is greater than a contact bounce time period.
Claim 9
Dependent Claim
108 words
In electronic flash apparatus including flash tube means for producing light in response to an ignition signal; flash termination switching means connected in series with the flash tube means for switching from a conductive to a non-conductive state to terminate a light flash; and triggering means including contact means and capacitor means for triggering the flash tube means and the flash termination switching means; the improvement comprising: gating means connected in series with the contact means and the capacitor means for inhibiting the triggering means from triggering the flash termination switching means to a conductive state unless a voltage at a selected point has attained a predetermined value.
Claim 10
Dependent Claim
108 words
In electronic flash apparatus including flash tube means for producing light in response to an ignition signal; flash termination switching means connected in series with the flash tube means for switching from a conductive to a non-conductive state to terminate a light flash; and triggering means including contact means and capacitor means for triggering the flash tube means and the flash termination switching means; the improvement comprising: gating means connected in series with the contact means and the capacitor means for inhibiting the triggering means from triggering the flash termination switching means to a conductive state unless a voltage at a selected point has attained a predetermined value.
Claim 11
Dependent Claim
24 words
The invention of claim 8 wherein the gating means comprises first zener diode means in series with the contact means and the capacitor means.
Claim 12
Dependent Claim
18 words
The invention of claim 9 and further comprising resistor means in parallel with the first zener diode means.
Claim 13
Dependent Claim
24 words
The invention of claim 10 and further comprising second zener diode means in parallel with the contact means and the first zener diode means.
Claim 14
Dependent Claim
15 words
The invention of claim 8 and further comprising: charging means for charging the capacitor means.
Claim 15
Dependent Claim
20 words
The invention of claim 12 wherein the voltage at the selected point is determined by voltage on the capacitor means.
Claim 16
Dependent Claim
35 words
The invention of claim 13 wherein the capacitor means is discharged during the light flash and wherein substantial charging of the capacitor means by the charging means occurs only after termination of the light flash.
Claim 17
Dependent Claim
32 words
The invention of claim 14 wherein the charging means has a charging time for charging the capacitor means to attain the predetermined value which is greater than a contact bounce time period.
References Cited (Backward Citations)
US3809954A
Cited
US3814985A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-10 | 1980-02-09 | 1980-08-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-10 | 1984-02-09 | 1984-08-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-10 | 1988-02-09 | 1988-08-10 | $7700.00 | Window Closed / Lapsed |