FR2495339A1 - FLASHLIGHT FOR PHOTOGRAPHIC OR OTHER APPARATUS - Google Patents

Abstract

The invention relates to flash lamps. It relates to a lamp comprising a first and a second lightning control circuit FC-1 and FC-2 comprising a first and a second lightning generator F1, F2. Many parts of the first lightning control circuit are used for controlling a second trigger signal generator E2 and the second flash tube circuit F2. The second FC-2 lightning control circuit can be connected to the first FC-1. Application to flash lamps for photographic cameras. (CF DRAWING IN BOPI)

Description

The present invention relates to an electric type flashlamp

  and more precisely a flashlamp

  intended for an optical apparatus such as a photo

  graphic. Recently, cameras with built-in flashlights have met with success

  Very important. However, these lamps give a light

  insufficient, except at a short distance, and the illumination

  often reduces the contrast or gives unwanted shadows

  ble. We also know the use of an indirect flash,

  but its usefulness is virtually negated by the reduction

  illumination of the object, when the source of lightning

has the same power.

  In the case of close-up photography, a

  auxiliary flash tube is usually mounted at the

  the lens of the camera in addition to the main tube and the main flashlamp

  is mounted on the housing of the device. In such an

  known, each of the flashlamps must have a cir-

  cooked lightning control system comprising a source of energy

  a voltage converter circuit for raising the voltage of the power source, a rectifier circuit of an AC voltage from the converter, an electric charge storage circuit comprising a main capacitor, a trip circuit. of a flash tube, and an automatic tuning circuit of

  the light of the lightning, etc. Thus, the device becomes

  Plicated and important, in addition to its high price.

  The invention relates to a general electrical appliance

  lightning or flashlight, having good

  characteristics during photography.

  It also concerns such a device or such

  lamp having a simple circuit, small and inexpensive.

More specifically, the invention.

  tion relates to a flashlamp comprising a first

  circuit and a second control circuit, a con-

  electrical connection of the first control circuit to the second, a lightning adjustment and synchronization device for adjusting the duration of the flashes of the first and the second control circuit, and a control of

  trigger for transmitting trigger signals

  first and second lightning control circuits,

  the first lightning control circuit having a provision

  electrical energy storage device for charging electrical energy into a main capacitor, and a first circuit comprising a first flash tube and a first trigger signal generating circuit, so that the main capacitor transmits power electrical energy to the first flash tube of the first circuit, the second control circuit comprising a second circuit which includes a second flash tube, and a second trigger signal generating circuit for controlling

  the transmission of electrical energy from the main capacitor

  the second tube of the second circuit.

  Other features and advantages of the invention

  will be better understood by reading the description

  which will follow examples of embodiment and with reference to the accompanying drawings in which: Figure 1 is a detailed electrical diagram

  of a control circuit of a flashlamp according to the

  vention; Figure 2 is a perspective showing the

  mechanical construction of the flashlamp according to the invention

  tion; Figure 3 is a perspective of a variant of a flashlamp according to the invention; and Figure 4 is a perspective of a device

  with a flashlamp according to the invention.

  Figure 1 shows a flashlight according to the invention. This lamp comprises a first lightning control circuit FC-1 and a second lightning control circuit FC-2 intended to be electrically connected to the first lightning control circuit FC-1.

  FC-1 circuit. The latter has a source A of energy in

  continuous circuit, a voltage converter circuit B for transforming a DC voltage from the source A into a high AC voltage, a circuit C for

  to rectify the AC voltage from the converts

  B, a circuit D for storing an electric charge

  than for transmitting electrical energy to the lightning tube, a first generator E1 trigger signals

  intended to trigger the lightning tube, a first circuit

  cooked F1 including a first lightning tube, a circuit

  Switching circuit, a switching circuit H for controlling

  circuit G, a control circuit I for the circuit H, a first light receiving circuit J1, a constant voltage circuit K, and a circuit L for

  to set the trigger signal transmitted to the flash tube.

  The energy source A comprises a battery of ac-

  accumulators 10 and a switch 11 connected in series with it. The converter B comprises a blocked oscillator OC which comprises a bias resistor 12 and a capacitor 13 of oscillations. The resistor 12 is mounted between a positive terminal of the battery 10 and the base of a switching transistor 14 whose collector is connected to the positive terminal of the battery 10 by the primary i5a of a transformer 15. The base of the transistor 14 which is preferably a silicon transistor with characteristics

  thrusts, is connected to the transmitter by the capacitor 13.

  The emitter of transistor 14 is connected to the negative terminal

  of the battery 10 via the switch 11.

  The transformer 15 has a secondary 15b of which a first

  end is connected to the base of transistor 14. A capacitor

  16 to absorb the transient voltages is connected in parallel with the secondary 15b of the

  transformer 15 and to the base-emitter path of the transistor

tor 14.

  A wave absorber capacitor 16 is connected in parallel with the secondary 15b of the transformer 15

  and the base-emitter circuit of transistor 14.

  The rectifier circuit C comprises an electric valve

  in the form of a diode 17 whose cathode is connected

  in high school l5b. The circuit D for storing a car-

  electric generator comprises a main capacitor 18 for

  a current limiting resistor 19 and a control lamp in the form of a neon discharge lamp 20 which is connected in series with the resistor 19, in parallel with the capacitor 18. A terminal of this capacitor 18 is connected to the anode of the diode 17 and its other bound

  is connected to the emitter of transistor 14 and to the ne-

  of the battery 10 via the switch 11.

  The first generator E1 of trigger signals

  It comprises a first trigger capacitor 22 and a first tripping transformer 23 having a primary 23a and a secondary 23b. A terminal of the primary

  23a is connected to the connection of a resistance 21 of

  and the capacitor 22. The first F1 circuit

  carries a first flash tube 24 which has two main electrodes 24a and 24b for conducting the current and a trigger electrode 24c placed near the tube 24 but outside thereof. The electrode 24c is connected

  at a first terminal of secondary 23b, and the first elec-

  main trode 24a is connected to the terminal of the capacitor

  circuit 18 of circuit D for storing an electric charge.

cudgel.

  The switching circuit G has a de-commun element

  in the form of a first thyristor 25, a capacitor

  switch 26 connected to the anode of the thyristor 25, a resistor

  switching resistor 27 connected in parallel with the thyristor, a gate capacitor 28, resistors 29 and

  30 and a capacitor 31. The circuit H of

  pure has a protection resistor 32 connected in parallel with the first flash tube 24, and a cut-off tube 33 connected to the thyristor 25 by the capacitor

26 switching.

  The cutoff control circuit I comprises a cut-off transformer 34 which has a primary 34a and a secondary 34b, a second thyristor 35 connected to the primary

  34a of the transformer 34, a capacitor 36 mounted in

  to the primary 34a via the thyristor, a gate resistor 37 and a resistor 38 of

  protection, as well as an IN integration circuit which

  Takes the resistor 39 and the capacitor 40 mounted in parallel. The first light receiving circuit J1

  includes a first receiver element in the form of a

  totransistor 41 whose collector is connected to the anode of the diode 17 of the rectifier circuit C via

  a resistor, and a switch 42 mounted between the

  phototransistor 41 and the gutter resistance 37

  te and the integration circuit IN of the cutoff control circuit I. The constant voltage circuit K comprises a constant voltage generating element in the form of a Zener diode 44, and connected capacitors 45 and 46

as shown.

  The circuit L for triggering signal signals

  ment comprises a synchronous switch 47 controlled in synchrony.

  chronism with the shutter of the camera (not shown in the figure), connected to the trigger capacitor 22, a diode 48 of which the anode is connected to the switch 47 and whose cathode is connected to the primary 23a, and a switch 49 connected in parallel with the secondary 23b of the first triggering transformer 23.

  The second FC-2 lightning control circuit

  takes a second generator E2 trigger signals, and a second circuit F2 comprising a flash tube and

  a second circuit J2 for receiving light.

  More precisely, the second generator E2 of

  triggers of the second control circuit FC-2 comprises a second trigger capacitor 50 and a

  second triggering transformer 52, having a predetermined

  Mayor 52a and a secondary 52b. The capacitor 50 is connected to the emitter of the transistor 14 of the converter circuit B of the first control circuit FC-1, via a contact 56a of a connector 56. A terminal of the primary 52a of the second transformer 52 is connected to the connection

  capacitor 50 and a resistor 51 tripping.

  The cathode of a second stop diode 53 is connected to the other terminal of the primary 52a. The anode of the diode 53 is connected to the connection of the switch 47 and the diode of the circuit

  K of trigger signal control, via

  contact 56b of the connector 56.

  The second circuit F. comprises a second tube with

  flashes 54 of annular shape. This tube 54 has two electrodes

  main conduction pins 54a and 54b and an electrode

  54c trigger. The electrode 54a is connected to the condenser

  main storage unit 18 by the contact 56a of the connector 56. The other main electrode 54b is connected

  to the first lightning tube 24 via the

tact 56c.

  The second circuit J2 light receiver has a

  second light receiving element in the form of a

  totransistor 55. This is mounted between the first cir-

  fired light receiving J1 and the cut-off control circuit 1 of the first flash control circuit FC-1, via the contacts 56d and 56e of the connector 56. In the flashlamp shown in FIG. certain criteria must be met by the tubes

  24 and 54, in the lightning control circuits.

  The current transmitted to the first tube 24 must be relatively

  large relative to that which is transmitted to the second tube 54, when the operation is satisfactory, so that the intensity of the light created by the first tube 24 is greater than that of the light of the second tube 54. For this purpose, the second tube 54 of the second circuit F2 must have a relatively low threshold impedance by

  compared to that of the first tube 24 of the first circuit F1.

  The second tube 54, to present such a low impedance

  ble, must have a low pressure gas and a low electrode spacing from the first tube 24. In addition, the internal resistance of the tube 54 is selected at a minimum.

  value above the usual value so that the

  The maximum flashes of the tubes 24 and 54 are approximately the same. The internal impedance of the tube 24 may be lower than that of the second tube. 54, an impedance such as a resistor or a charge coil being connected in series with the second tube 54. If the first tube 24 has a

  low impedance compared to the second tube 54, the

  the lightning of the tube 24 tends to be assured before that of the second tube 54, and the element which presents

  the impedance can be used so that it avoids this phenomenon.

  The operation of the flashlamp described

previously is the following.

  When the switch 11 of the energy source is closed, the converter circuit V begins to oscillate and a high voltage is induced in the secondary 15b of the transformer 15. This voltage is rectified in the circuit C and an electric charge is maintained in the main capacitor 18. The capacitors 22, 26, 36,

  45, 46 and 50 also accumulate an electric charge. Lors-

  that the main capacitor 18 has reached a voltage of

  20, the indicator lamp 20 illuminates, indicating that the device is ready for triggering the tube 24. The operation of the circuits of the flashlamps is initiated by the circuit L for setting trip signals and in particular when the switch 47 is closed. Then, the capacitor 22 discharges into the loop which comprises the switch 47, the diode 48 of the circuit L for adjusting the

  triggering signals and the primary 23a of the first trans-

  23. A trigger pulse is

  secondary terminals 23b and it is applied to the elec-

  trode 24c tripping the first tube 24 flashes

  when the switch 49 is open, so that the first

  first tube 24 is triggered and forms a flash. Simultaneously, when the switch 47 is closed, the second trigger capacitor of the second generator E2 discharges into the loop which comprises the contact 56a of the connector

  56, the switch 47, the contact 56b and the primary 52a.

  A trigger pulse appears at the terminals of the

  24b and it reaches the trigger electrode 24c.

  the second tube 54, so that it forms a flash, the main capacitor 18 discharging into the tubes 24 and 54. The thyristor 25 leads, because it is

  polarized for this purpose by the voltage across the terminals of

  28. Unless otherwise interrupted, the flash continues until the main capacitor 18 has discharged through the tubes 24 and 54 to a value such that the voltage across the main electrodes does not sustain. plus conduction in the tubes. This phenomenon

  usually appears after several milliseconds.

  The light receiving circuits Ji and J2 detect the illumination provided by the lightning tubes 24

  and 54 and phototransistors 41 and 55 become conductive

  tors. In this case, the switch 42 of the first circuit J1 is opened by introduction and connection of the connector

  56. Thus, an electrical charge is maintained by the

  denser 40 of the integration circuit IN.

  When the capacitor 40 is charged to a voltage

  predetermined voltage after a given time interval, the thyristor 35 is biased in the conductive state. Then,

  the capacitor 36 discharges into the primary 34a of the trans-

  trainer 34 and a high voltage pulse is induced in the secondary 34b. The pulse triggers

the cutoff tube 33.

  When the cut-off tube of the circuit H becomes conductive, the discharge current for the first and the second tube 24 and 54 are shunted in the tube 33 and, simultaneously, the electric charge retained by

  the switching capacitor 26 discharges through the

  intermediate of the tube 33 and the resistor 27 so that after a time interval which depends on a constant

  determined by the combination of the value of the con-

  denser 26 and that of the resistor 27, the thyristor

  stops driving, and tubes 24 and 54 are immediately

  For example, the flash times of the tubes 24 and 27 are the same or substantially the same, the flash of the first tube 24 having an intensity greater than that of the

second tube 54.

  In the flashlamp shown in FIG. 1, when the switch 49 of the trip signal setting circuit L is closed, the secondary 23b of the

  first triggering transformer 23 is short-circuited.

  cuité by the switch 49 so that the high voltage

  is not created at the terminals of secondary 23b. In these circumstances

  the first tube 24 is not primed and only the

  second tube 54 is primed. Thus, the close photograph

  This can be done by closing switch 49 of circuit L. In addition, when connector 56 is removed from first circuit FC-1, i.e. when the second

  lightning control circuit FC-2 is disconnected from the first

  In the first circuit FC-1, the switch 42 of the first light receiving circuit J1 closes so that the first phototransistor 41 is connected to the cutoff control circuit I. Under these conditions, the first FC-1 circuit can

  be used alone as a conventional flashlamp.

  Figure 2 shows the mechanical construction

  very simplified apparatus according to the invention. More pre-

  this apparatus comprises a first FU-1 flashlamp comprising the first flash control circuit FC-1, and a second flashlamp FU-2 comprising the second flashback control circuit FC-2, mechanically connected.

  and electrically by the connector 56.

  The first flashlamp FU-1 is housed in a housing 61 which has a first portion 61a and a second 61b which is pivotable relative to the first 61a at a hinge 61c. So the second part

  61b can turn relative to the first 6la as

  indicated by the arrow 63. The first part 61a has a detection

  light source in the form of the phototransistor 41 and a first

  first lightning formation member 62 which contains the first

1 0

  first lightning tube 24 shown in FIG.

  The second FU-2 flashlamp includes a second member 71 which has an annular frame 72 housing the second flash control circuit FC-1 which includes the second flash tube 54 and a second light detector in the form of the phototransistor 5 The second flashlamp

  PU-2 is connected to the first FU-1 by connector 56.

  The apparatus described can be used both for the use

  in direct and indirect lightning. The second FU-2 lamp transmits a direct flash while the first lamp

  FU-1 may form an indirect flash, part 61b of the

  tier 61 being adjusted to any suitable inclination by

report to Part 61a.

  Figure 3 shows a variant of the

  Figure 2. In the apparatus of Figure 3, the second FU-2 flashlamp has a rectangular housing

  63 which contains a second member 72 for forming lightning.

  The latter has a second flash tube (not shown on

  the drawings) of tubular form. The second circuit of

  FC-2 is incorporated in the rectangular housing.

  re 63 aui can be mounted on a camera body-

  graphic. A light detector in the form of

  transistor 55 is placed at the front face of the housing 63. In the apparatus of FIG. 3, the second flash-forming member may have at least two second flash tubes,

where appropriate.

  Figure 4 represents another variant of the application

  same according to the invention. As shown in this figure, the apparatus includes a first FU-1 flashlamp having

  a rectangular housing 62 mounted on the outside of an appliance

  photographic camera 100, and a second flashlamp

  FU-2 disposed on the periphery of an objective 101 of the

  100. The first lamp FU-1 has a window 62a of

  a first flash tube (not shown). Meadow-

  The first lightning control circuit FC-1 shown in FIG. 1 is housed in the apparatus 100, and a light detector in the form of a first phototransistor 41 is placed at the front of the apparatus 100. FC-1 Lightning Control circuit operates the first FU-1 flashlamp. The second FU-2 flashlamp comprises a second flash-control circuit FC-2, of the type shown in FIG. 1. This second circuit FC-2 is housed in a box 102 of the camera

  100. A second annular flash tube 54 of the second cir-

  cooked FC-2 is located on the periphery of Objective 101 of the

  100. A light detector in the form of a second

  phototransistor 55 is placed at the front of the second bot-

  Tier 102 of the apparatus 100. The first circuit FC-1 of

  is connected electrically and mechanically to the

  Cond FC-2 circuit through a connector 56.

  In the apparatus according to the invention, the construction

  The circuit is very simplified because many elements

  of the lightning control circuit are used in common

  by the first and second flashlamps.

  In addition, the apparatus according to the invention can be used in particular photographs, for example

  with indirect lighting in a closed room or in a studio,

  long-distance and short-range photography

  distance by use of a control circuit of

trip signals.

  The foregoing description shows that the invention

  tion has the advantages indicated above, as well as

that others.

  Of course, various modifications may be made by those skilled in the art to the devices which have just been described as non-limiting examples only.

  without departing from the scope of the invention.

Claims (15)

  1. A flashlamp, characterized in that it comprises   takes a first lightning control circuit (FC-1), a second lightning control circuit (FC-2), a means (56> for electrically connecting the first lightning control circuit to the second, a timing adjustment device for adjusting the duration of the flashes of the first and second lightning control circuit, and   a device for adjusting the triggering signals of   for transmitting trip signals to the first and second lightning control circuit (PC-1, FC-2),   the first lightning control circuit comprising a   Positive Energy Storage (A-D) intended   to charge electrical energy into a primary capacitor   storage (18), and a first circuit (F1) comprising   taking a first lightning tube (24) and a first gen-   initiator signal (E1) for causing transmission of electrical energy by the main storage capacitor to the first flash tube (24> of the first circuit, the second flash control circuit (FC-2 ) comprising a second circuit (P2) which comprises a   second lightning tube (54), and a second light generator   triggering signals (E2) intended to induce trans-   electrical energy mission by the main storage capacitor (18) to the second flash tube (54) of the second circuit. 2. Lamp according to claim 1, characterized in that the flash synchronization adjusting device comprises an internal impedance of the first flash tube (24) and an internal impedance of the second flash tube (54),   this impedance being greater than that of the first tube.   3. Lamp according to claim 1, characterized in   what the synchronizing signal setting device   comprises a circuit (L) for adjusting the sync signals   chronization connected in common to the first generator (E1) of tripping signals of the first flash control circuit (FC-1) and to the second generator (E2) of tripping signals of the second flash control circuit (FC-2).   4. Lamp according to claim 3, characterized in   the circuit (L) for setting the trigger signals   comprises a synchronous switch (47) controlled in synchronism with the operation of a shutter of a   photographic camera.   5. Lamp according to claim 4, characterized in   what the trigger signal generator (E1) coM-   also takes a device to block the transmission of   mission of the current to the second signal generator trigger (E2).   6. Lamp according to claim 4, characterized in   the circuit (L) for setting the trigger signals   further comprises a device (48) for blocking the current for the first trigger generator (E1). Lamp according to claim 3, characterized in that   the circuit (L) for setting the trigger signals   includes a switch (49) for preventing the   creation of the trigger signal by the first gener-   trigger signal (E1).   8. Lamp according to claim 5, characterized in that the locking device (48) comprises a diode   connected to the synchronous switch (47) and the first gen-   trigger signal (E1).   9. Lamp according to claim 6, characterized in that the locking device (53) comprises a diode   connected to the synchronous switch (47) and the second genera-   trigger signal (E2).   Lamp according to claim 1, characterized in that   at least one of the first and second circuits of   lightning (FC-1, FC-2) has a light receiving circuit   first (Ji, J2) excited by light from the first   circuit and the second lightning tube circuit, and a cir-   cooked (H) control of cutoff controlled by a signal pro   coming from the light receiving circuit and intended to control the interruption of the lightning of the first circuit and the second flash tube circuit.   11. Lamp according to claim 10, characterized in that the first lightning control circuit (FC-1) S has a first light-receiving circuit (J1) excited by light of the first and second tube circuit. lightning, and a cutoff control circuit (H) controlled by a   signal from at least one of the first and second cir-   light receivers and intended to control the opera-   rations of interruption of the flashes of the first and second flash tube circuit.   12. Lamp according to claim 10, characterized in that the first circuit (J.) receiving lightning   comprises a light sensor element (41), and a   mutator (42) for connecting and disconnecting the cut-off control circuit (H) according to the connection or   disconnecting a connector (56).   13. Lamp according to claim 10, characterized in that the first lightning control circuit   (FC-1) includes a switching circuit for   order the first flash tube circuit (F1) and se-   flash tube circuit (F2), and a cut-off circuit (H) for extinguishing a first flash tube (24)   of the first circuit and a second lightning tube (54) of the   cond circuit using a cut control signal   from the cutoff control circuit.   14. Lamp according to claim 1, characterized in that the first and the second signal generator of   tripping (E1, E2) each have a capacitor of   latching (22, 50) and a trip transformer   (23, 52) which has a primary connected to the trigger capacitor   and a secondary connected to a trigger electrode   (24c, 54-c) of the flash tube (24, 54).   15. Lamp according to claim 1, characterized in that the device for storing an electric charge (AD) comprises a voltage converter (B) for transforming a DC voltage of a DC current source (A). ), an AC voltage, and a circuit (C) for rectifying the AC voltage to a DC voltage.