US3864601A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic flash device
Assignee: Rollei Werke Franke und Heidecke GmbH and Co KG
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Filing: 1973-05-14
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Granted: 1975-02-04
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Expires: 1993-05-14
Abstract
Abstract Electronic flash apparatus for photographic purposes, having a main storage capacitor for initially powering a flash tube, and at least one additional storage capacitor providing additional power for the flash tube if more light is needed than can be produced from the main or first storage capacitor. A quench tube or short circuiting tube is provided for terminating the flash when sufficient light for the desired photographic purpose has been produced. A phototransistor responsive to the amount of light reflected from the subject being photographed, serves to control both the operation of the quench tube and the operation of an actuating tube when serves to connect the second storage capacitor operatively to the flash tube. Safeguard circuits or interlocking circuits are provided to insure against faulty operation.
Inventors
- 👤 Arthur Schneider
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:36
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
239 words
Electronic flash apparatus for photographic purposes comprising flash tube means for generating a light flash, a first storage capacitor for initially powering said flash tube means, a second storage capacitor for supplying additional power when needed to said flash tube means, light sensitive means for deriving a changing voltage the rate of which is a function of the light flash reflected from a subject being photographed, quench means shiftable from an inoperative state to an operative state and effective, when shifted to its operative state, to terminate a flash then in progress, first circuit means for operatively connecting said second storage capacitor to said flash tube means when the rate of said changing voltage is below a given rate and operatively disconnecting it from said flash tube means when the rate of said changing voltage is above said given rate, said first circuit means including an ignition thyristor, an integration capacitor for triggering said ignition thyristor when said rate of changing voltage is below said given rate, integration circuit means for controlling operation of said quench means, said integration circuit means being responsive to light reflected from a subject being photographed and a control thyristor bridging said integration capacitor, said control thyristor having a gate coupled to said means for deriving a changing voltage through a differentiation capacitor, said control thyristor serving to short circuit said integration capacitor when the rate of said changing voltage exceeds a predetermined rate.
Claim 2
Dependent Claim
239 words
Electronic flash apparatus for photographic purposes comprising flash tube means for generating a light flash, a first storage capacitor for initially powering said flash tube means, a second storage capacitor for supplying additional power when needed to said flash tube means, light sensitive means for deriving a changing voltage the rate of which is a function of the light flash reflected from a subject being photographed, quench means shiftable from an inoperative state to an operative state and effective, when shifted to its operative state, to terminate a flash then in progress, first circuit means for operatively connecting said second storage capacitor to said flash tube means when the rate of said changing voltage is below a given rate and operatively disconnecting it from said flash tube means when the rate of said changing voltage is above said given rate, said first circuit means including an ignition thyristor, an integration capacitor for triggering said ignition thyristor when said rate of changing voltage is below said given rate, integration circuit means for controlling operation of said quench means, said integration circuit means being responsive to light reflected from a subject being photographed and a control thyristor bridging said integration capacitor, said control thyristor having a gate coupled to said means for deriving a changing voltage through a differentiation capacitor, said control thyristor serving to short circuit said integration capacitor when the rate of said changing voltage exceeds a predetermined rate.
Claim 3
Dependent Claim
66 words
The invention defined in claim 1, wherein said control circuit means comprises a phototransistor responsive to said reflected light, a thyristor (28) effective, when triggered, to shift said switch means to a conductive state, And means connected to said phototransistor to block said thyristor (28) from being triggered when said initial brilliance of said reflected light at the beginning of a flash exceeds said predetermined value.
Claim 4
Dependent Claim
234 words
Electronic flash apparatus for photographic purposes comprising flash tube means for generating a light flash, a first storage capacitor for initially powering said flash tube means, a second storage capacitor for supplying additional power when needed to said flash tube means, light sensitive means for deriving a changing voltage the rate of which is a function of the light flash reflected from a subject being photographed, quench means shiftable from an inoperative state to an operative state and effective, when shifted to its operative state, to terminate a flash then in progress, first circuit means for operatively connecting said second storage capacitor to said flash tube means when the rate of said changing voltage is below a given rate and operatively disconnecting it from said flash tube means when the rate of said changing voltage is above said given rate, said first circuit means including an ignition thyristor, an integration capacitor for triggering said ignition thyristor when said rate of changing voltage is below said given rate, integration circuit means for controlling operation of said quench means, said integration circuit means being responsive to said rate of changing voltage, and a control thyristor bridging said integration capacitor, said control thyristor having a gate coupled to said integration circuit means through a differentiation capacitor, said control thyristor serving to short circuit said integration capacitor when the rate of said changing voltage exceeds a predetermined rate.
Claim 5
Dependent Claim
234 words
Electronic flash apparatus for photographic purposes comprising flash tube means for generating a light flash, a first storage capacitor for initially powering said flash tube means, a second storage capacitor for supplying additional power when needed to said flash tube means, light sensitive means for deriving a changing voltage the rate of which is a function of the light flash reflected from a subject being photographed, quench means shiftable from an inoperative state to an operative state and effective, when shifted to its operative state, to terminate a flash then in progress, first circuit means for operatively connecting said second storage capacitor to said flash tube means when the rate of said changing voltage is below a given rate and operatively disconnecting it from said flash tube means when the rate of said changing voltage is above said given rate, said first circuit means including an ignition thyristor, an integration capacitor for triggering said ignition thyristor when said rate of changing voltage is below said given rate, integration circuit means for controlling operation of said quench means, said integration circuit means being responsive to said rate of changing voltage, and a control thyristor bridging said integration capacitor, said control thyristor having a gate coupled to said integration circuit means through a differentiation capacitor, said control thyristor serving to short circuit said integration capacitor when the rate of said changing voltage exceeds a predetermined rate.
Claim 6
Dependent Claim
172 words
Electronic flash apparatus for photographic purposes, comprising flash tube means for generating a light flash, a first storage capacitor for initially powering said flash tube means, a second storage capacitor for supplying additional power when needed to said flash tube means, quench means shiftable from an inoperative state to an operative state and effective when shifted to its operative state, to terminate a flash then in progress, light sensitive means for deriving a changing voltage the rate of which is a function of the light flash reflected from a subject being photographed, actuating means connected to said light sensitive means for supplying power from said second storage capacitor to said flash tube means only when said rate of changing voltage is below a given rate, said actuating means including an integration capacitor for operating said actuating means and means responsive to said rate of changing voltage for short circuiting said integration capacitor to prevent operation of said actuating means only when said rate of said changing voltage is above a given rate.
Claim 7
Dependent Claim
172 words
Electronic flash apparatus for photographic purposes, comprising flash tube means for generating a light flash, a first storage capacitor for initially powering said flash tube means, a second storage capacitor for supplying additional power when needed to said flash tube means, quench means shiftable from an inoperative state to an operative state and effective when shifted to its operative state, to terminate a flash then in progress, light sensitive means for deriving a changing voltage the rate of which is a function of the light flash reflected from a subject being photographed, actuating means connected to said light sensitive means for supplying power from said second storage capacitor to said flash tube means only when said rate of changing voltage is below a given rate, said actuating means including an integration capacitor for operating said actuating means and means responsive to said rate of changing voltage for short circuiting said integration capacitor to prevent operation of said actuating means only when said rate of said changing voltage is above a given rate.
Claim 8
Dependent Claim
22 words
Apparatus as defined in claim 4, further including safety means operating said short circuiting means when said quench means has been operated.
Claim 9
Dependent Claim
201 words
Electronic flash apparatus comprising: a. a main storage capacitor; b. a second storage capacitor; c. electrical supply means for electrically charging said capacitors; d. flash tube means connected to said storage capacitors for generating a light flash upon discharge of one or both of said capacitors through said flash tube means; e. quench means shiftable from an inoperative state to an operative state and effective when in an operative state to short circuit whatever capacitor is then discharging through said flash tube means, thereby to terminate a flash which is then in progress; f. light sensitive means responsive to the intensity of light reflected from a subject being photographed to generate a changing voltage the rate of change of which is a function of the intensity of said reflected light; and g. circuit means responsive to the rate of change of said changing voltage for operatively connecting said second capacitor to said flash tube means to discharge therethrough only when The rate of change of said changing voltage is less than a predetermined value and for operatively disconnecting said second capacitor from said flash tube means when the rate of change of said changing voltage is greater than a predetermined value.
Claim 10
Dependent Claim
201 words
Electronic flash apparatus comprising: a. a main storage capacitor; b. a second storage capacitor; c. electrical supply means for electrically charging said capacitors; d. flash tube means connected to said storage capacitors for generating a light flash upon discharge of one or both of said capacitors through said flash tube means; e. quench means shiftable from an inoperative state to an operative state and effective when in an operative state to short circuit whatever capacitor is then discharging through said flash tube means, thereby to terminate a flash which is then in progress; f. light sensitive means responsive to the intensity of light reflected from a subject being photographed to generate a changing voltage the rate of change of which is a function of the intensity of said reflected light; and g. circuit means responsive to the rate of change of said changing voltage for operatively connecting said second capacitor to said flash tube means to discharge therethrough only when The rate of change of said changing voltage is less than a predetermined value and for operatively disconnecting said second capacitor from said flash tube means when the rate of change of said changing voltage is greater than a predetermined value.
Claim 11
Dependent Claim
70 words
The invention as defined in claim 1, further comprising safety means 33, 34, 35 additionally coupling said gate of said control thyristor 31 to said quench means 17, said safety means causing said control thyristor to become conductive upon shifting said quench means from its inoperative state to its operative state, thereby causing said control thyristor 31 to short circuit said integration capacitor 29 when said quench means becomes operative.
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) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |