Electronic flashlamp apparatus having a plurality of flash tubes successively ignited

Claim 2

Flashlamp apparatus for photographic purposes comprising a series of associated flash tubes each powered by an individual capacitor, means for firing said flash tubes successively in rapid sequence, means for measuring and integrating the quantity of reflected light reaching the flashlamp apparatus from a subject being photographed, and means responsive to said measuring and integrating means for terminating the successive firing of said flash tubes when the integrated quantity of reflected light reaches a predetermined threshold value, so that further firing of flash tubes will not occur after said threshold value has been reached.

Claim 3

Flashlamp apparatus as defined in claim 1, wherein each successive flash tube in the series produces, when flashed, a greater quantity of light than the preceding flash tube in the series.

Claim 4

Flashlamp apparatus as defined in claim 1, wherein the light values produced by flashing the successive tubes have the relation to each other of an ascending quadratic series.

Claim 5

Flashlamp apparatus as defined in claim 1, further including means responsive to said measuring and integrating means for terminating a particular flash then in progress when said threshold value is reached during the progress of a particular flash.

Claim 6

Flashlamp apparatus, particularly for photographic purposes, comprising a plurality of flash units each including a flash tube, a capacitor individual to that flash tube, and ignition circuit means including a thyristor for controlling the ignition circuit means, impulse generating means for activating said thyristors successively in turn, and means for interrupting effective operation of said impulse generating means, said means for interrupting effective operation of said impulse generating means including a threshold indicator (169), a transistor (165) operatively connected to said indicator and rendered conductive when a threshold value is reached, and connections from said transistor to said thyristors for supplying control grids of the thyristors with a negative bias voltage when said transistor is conductive, to prevent impulses from being passed through said thyristors.

Claim 7

Flashlamp apparatus, particularly for photographic purposes, comprising a plurality of flash units each including a flash tube, a capacitor individual to that flash tube, and ignition circuit means including a thyristor for controlling the ignition circuit means, impulse generating means for activating said thyristors successively in turn, and means for interrupting effective operation of said impulse generating means, said means for interrupting effective operation of said impulse generating means including a threshold indicator (169), a transistor (165) operatively connected to said indicator and rendered conductive when a threshold value is reached, and connections from said transistor to said thyristors for supplying control grids of the thyristors with a negative bias voltage when said transistor is conductive, to prevent impulses from being passed through said thyristors.

Claim 8

A construction as defined in claim 5, wherein saiD means for activating said thyristors in turn includes a ring selector impulse distributor.

Claim 9

A construction as defined in claim 5, wherein said means for activating said thyristors in turn includes an ignition impulse generator and an ignition impulse distributor in series with each other.

Claim 10

A construction as defined in claim 5, further including a photoelectric light transformer responsive to light reflected from a subject illuminated by said apparatus, and an integrating device responsive to said photoelectric light transformer, said threshold indicator being operatively connected to and responsive to said integrating device.

Claim 11

A construction as defined in claim 5, wherein each of said flash units is provided with a special direct-voltage transformer (171, 172, 173).

Claim 12

A construction as defined in claim 5, in which each of said flash units produces, when flashed, a different light value from that produced by the other units, the light values of the respective light units in the order in which they are respectively flashed being arranged in a geometric progression.

Claim 13

A construction as defined in claim 5, further comprising a separate quench tube connected in parallel with each of said flashlamps and serving, when ignited, to short circuit the flashlamp with which it is connected in parallel, thereby to terminate any flash then in progress in the flashlamp with which it is connected, and means responsive to light reflected from a subject illuminated by said flashlamps for igniting the quench tube of at least a flashlamp in which a flash is then in progress and for concomitantly interrupting effective operation of said impulse generating means so that further flashlamps will not be ignited, when the light reflected from said subject reaches a selected value.

Claim 14

A construction as defined in claim 5, further comprising a separate quench tube connected in parallel with each of said flashlamps and serving, when ignited, to short circuit the flashlamp with which it is connected in parallel, thereby to terminate any flash then in progress in the flashlamp with which it is connected, and means responsive to light reflected from a subject illuminated by said flashlamps for igniting the quench tube of at least a flashlamp in which a flash is then in progress, when the light reflected from said subject reaches a selected value.

Claim 15

A construction as defined in claim 12, in which said means for igniting the quench tube ignites only the quench tube of a flashlamp in which a flash is then in progress, without igniting the quench tube of any flashlamp in which a flash is not occurring.

Claim 16

Flashlamp apparatus for photographic purposes comprising flash tube means, a series of individual capacitors for powering said flash tube means, means for causing said capacitors to fire said flash tube means in a series of successive flashes in rapid sequence, means for measuring and integrating the quantity of reflected light reaching the flashlamp apparatus from a subject being photographed, and means responsive to said measuring and integrating means for terminating the successive firing of flashes when the integrated quantity of reflected light reaches a predetermined threshold value, so that further firing of flashes will not occur after said threshold value has been reached.

Claim 17

Flashlamp apparatus for photographic purposes comprising flash tube means, a series of individual capacitors for powering said flash tube means, means for causing said capacitors to fire said flash tube means in a series of successive flashes in rapid sequence, means for measuring and integrating the quantity of reflected light reaching the flashlamp apparatus from a subject being photographed, and means responsive to said measuring and integrating means for terminating the successive firing of flashes when the integrated quantity of reflected light reaches a predetermined threshold value, so that further firing of flashes will not occur after said threshold value has been reached.