US2480122A

US2480122A - Electron discharge apparatus

Info

Publication number: US2480122A
Application number: US773280A
Authority: US
Inventors: Richard W Daniels
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-09-10
Filing date: 1947-09-10
Publication date: 1949-08-30
Anticipated expiration: 1966-08-30

Description

Aug. 30, 1949. R w, N s 2,480,122

ELECTRON DISCHARGE A PARATUS Filed Sept. 10, 1947 2 Sheets-Sheet l 5/ 52 /3 I I v INVENTOR. I62 16/ Richard W Dumb/s Attorney Aug 30,1949. w, N s 2,480,122

ELECTRON DISCHARGE APPARATUS Filed Sept. 10, 1947 2 Sheets-Sheet 2 uvvszvroa. Richard W Danie/s Affomay Patented Aug. 30, 1949 UNITED STATES PATENT OFFICE '(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 8 Claims.

This invention relates to electron discharge apparatus, particularly such apparatus as is used for producing a brilliant flash of actinic light for photographic purposes. More particularly, this invention relates to a holder in which an electron discharge device capable of producing a flash of photographic light may be mounted.

It is an object of this invention to provide means for improving the timing control over a flash of actinic light.

It is another object of this invention to provide a holder for an electron discharge device having an adjustable member whereby the firing of the device may be regulated for optimum performance.

It is still another object of this invention to provide a holder for an electron discharge device having adjustable means whereby the holder may accept devices of difierent sizes and shapes with equal functional effectiveness.

In the following description there will be described photographic apparatus for producing a brilliant flash of actinic light. An important element of this apparatus is the electron discharge device and holder of the instant invention.

Referring to the drawing, Fig. l is a schematic diagram of an electric control circuit for energizing electron discharge apparatus to produce a flash of light. v

Fig. 2 is a face view of the electron discharge apparatus which produces the flash of photographic light.

Fig. 3 is a face view of a camera showing a tripping means whereby the flash of actinic light may be synchronized with the opening of the camera shutter.

Fig. 4 is a fragmentary top view, partially sectioned, of the electron discharge apparatus of Fig. 2.

Fig. 5 is a partially sectioned view of the apparatus of Fig. 4, taken along the oblique line 3-5 in Fig. 4.

Fig. 6 is an enlarged face view of the camera shown in Fig. 3.

The energizing circuit In Fig. 1, the plug adapted to be connected to a source of 110 volt alternate current power, is connected to the primary winding l2 of a transformer l3 through a switch H. A high voltage secondary winding l5 of the transformer I3 is grounded at one end as shown at l6, and is connected at the other end to the plate of 9. rectifler tube H. The rectifier cathode is heated in conventional manner by energy from a low voltage secondary winding i8 013 the transformer l3. With the rectifier tube thus connected, the cathode conductor l9 has applied thereto a relatively high uni-directional potential.

Conductor I9 is connected to a conductor 2| through a bridging contact, 22 of a relay 23. Between conductor 2| and the ground It is connected a storage capacitor 24. Thus whenever transformer l3 and relay 23 are energized, capacitor 24 will be connected to, and charged by, a high voltage direct current source in the form of rectifier l1.

Capacitors

25 and 26 may be successively paralleled with capacitor 24 through a multiterminal switch 21, having a rotatable bridging member 28. In the particular position shown for bridging member 28, in Fig. 1, only capacitor 25 is connected to conductor 2| so that th total capacitance charged from the high voltage direct current line is the sum of

capacitors

24 and 25. It will be manifest from the drawing that all three capacitors may be paralleled by rotating the bridging member 28 one position counter-clockwise; while by rotating member 28 one position clockwise, only capacitor 24 will be connected to conductor 2|.

The relay 23 is employed in the circuit of Fig. 1 to insure that the high voltage conductor |'9 will not be connected to the capacitors 2426 until the apparatus has been operating long enough to insure adequate operating temperature in the cathode of rectifier l1. The necessary time delay is provided by a small motor 3| connected, through gears 32, to a conducting disk 33. One terminal of motor 3| is connected permanently through a conductor 34 to one side of the plug The other side of the motor is connected to the other side of the alternating current source through a conductor 35 and through the relay contact 22. Thus as soon as the switch I4 is closed to start heating of the cathode of rectifier H, the motor 3| is also energized to institute rotation of the disk 33. In sliding contact with the disk 33 is a brush 35 connected to the conductor 34. Disk 33 carries a contact 31 which bears against a stationary contact 38 whenever the disk has been rotated a predetermined distance. Contact 38 is connected to one side of the coil 39 of relay 23, the other side of which is connected to the alternating current conductor 35. Thus, a predetermined time after closing of the switch i4, when the motor 3| has rotated the disk 33 so as to move the contact 31 into engagement with the contact 38, the relay coil 39 is energized, thereby lifting the armature 4| and causing contact 22 to complete the circuit tor the capacitors 24-28. Deenergization of the motor 2|, by the lifting of contact 22, would normally cause the disk 22 to snap back under the impulse oi a torque biasing spring 42; but this is prevented by an interlock member 43, attached to the armature 4| which physically engages the contact 31 and holds it against the contact 30. The energizing circuit for coil 39 through contacts 31-32 is thus held closed by virtue of the raised position of armature 4|. Under this condition the capacitors 24-20 will be charged from rectifier II, the voltage of this charge appearing between conductor 4 connected to ground I6, and the high voltage direct current conductor 2|. The quantity of the charge depends on the number of capacitors 24-28 across the line, which in turn depends on the position of the switch 21.

An indicator light connected across the primary winding I2, shows when the apparatus has been energized by the closing of switch It. A high voltage indicator light 62 is also placed across the primary winding I2 through an auxiliary contact 53 carried by the armature 4| of relay 23. Light 52 indicates that the delay time has passed, and that the high voltage from rectifier II has been applied to the conductor 2|, and to the capacitors 24-25.

In order that a high voltage will not remain on the conductor 2| when the apparatus is not in use, means must be provided for discharging the capacitors 24-26. To this end the conductor 2| is grounded through a resistor 55 and a relay 56, the coil of which is energized whenever the switch I I is closed, thereby opening the grounding circuit.

The apparatus of this invention also employs a high voltage alternating current, which is derived through a transformer 6|, the primary winding 62 of which is connected in parallel with the primary winding I2 through a plug 63, which is in turn connected to a switch on the camera of Fig. 3 (to be described later). One side of the secondary winding 64 of the transformer 6| is grounded through a conductor 65, and the other side is connected to a conductor 60. A plug 61 is provided to which the ground conductor 44 and the high voltage direct current conductor 2| are connected, and also to which the ground conductor 65 and the high voltage alternating current conductor 66 are connected.

The circuit of Fig. 1 thus makes available for the electron discharge apparatus of Fig. 2, a direct current potential between conductors I" and 2|, as stored on the capacitors 24-26. It also makes available a high voltage alternating current between the

conductors

55 and 66. This latter voltage. however, does not appear until the conductors of the plug 03 have been bridged by operation of the switch on the camera shown in Fig. 3.

The camera In Fig. 3 there is shown the face of a camera ii having a conventional lens assembly I2, which includes a shutter setting lever I3 and a shutter release lever l4. Pivoted on the face of the camera II by a pin i5 is a cam arm it having a knob TI which bears against a protuberant portion of a spring contact I8. Spring contact 78 cooperates with an opposed spring contact 19 to comprise a normally open switch, which is closed momentarily as the cam arm I6 rotates counterclockwise. The contacts 18 and I0 are connected through a plug 8| to conductors 82 which may be connected'to the plug 63. In series with one of the conductors 82 is a normally open foot switch 83, which must be held down during operation of the camera in order to complete the circuit for energizing the primary winding 62 of the transiormer 6|.

Tripping oi the camera, which causes counterclockwise motion of the lever I3 in the conventional manner, also efiectuates, through a link 84, the afore-mentioned counter-clockwise rotation 01' the cam arm 16 and thereby energizes momentarily the primary winding 62. The camera tripping lever II is actuated through a solenoid 85 energized by a small battery 86 through a manually carried push button 81.

For optimum photographic results it is necessary that the shutter opening of the camera be precisely synchronized with respect to the closing of the light tripping contacts I8 and 19. In order to achieve this synchronization for various makes of cameras 'II, it is desirable that the length of the link 04 be adjustable. As shown in Fig. 6, this is done by making the link 86 in two parts. One of these parts consists of a female fitting 9| connected through a rod 92 to an extension arm 93 firmly aflixed to the shutter setting lever 13. Into the female fitting 9| is threaded the other of these parts, a male fittingjfl having a hexagon head 95, swiveled on an arm 96, the end of which is pivoted at 91 to the upper end of the cam arm I6. By adjusting the fitting 94 in the fitting 9|, the length of the link 84 may be altered to synchronize properly the shutter opening with the closing of contacts I8 and I9, and hence with the flash of light from the flash apparatus shown in Fi 2.

The flash lamp The flash lamp, or electron discharge apparatus, forming the claimed subject matter of this invention is illustrated in Figs. 2, 4, and 5. Referring to Fig. 2, the apparatus includes a light reflector MI, in front of which is mounted an electron discharge device I02. The discharge device |02 comprises a tubular, helical, electron discharge envelope I03 surrounded by a transparent cylindrical cover I. The bottomtermination of the envelope I03 contains an electrode I05 and the top termination likewise contains an electrode I06. The electron discharge device I02 is of the plug-in type, being provided with parallel prongs I01, I08, and I00. The prong I01 is connected to 'an upstanding conducting post III, disposed parallel to the axis of the helical envelope I03 just outside the convolutions thereof. A loop I I2 extending internally of the helix I03 and attached to the post III serves to physically support one side of the envelope I03. The other side of the envelope is similarly supported by a post I I3, connected to the prong I09, and having a loop II'fi similar to the loop H2. The post III is electrically connected by a wire I I5 to the electrode I05, and the post H3 is connected by a wire II 6 to the other electrode I06.

High voltage direct current is applied to the envelope M3, for discharge therethrough, by conductors |2I and I22, the former being connected to the prong I01 and the latter to the prong I09 through a suitable female plug in the electron discharge apparatus of Fig. 2. The conductor I 2| is connected to the ground conductor M (Fig. 1), and the conductor I22 is connected to the high voltage direct current conductor 2|, through the gig 61, as shown by the schematic dotted lines It will be seen from the description of the apparatus thus far that when the electron discharge apparatus of Fig. 2 is connected to the circuit of Fig. 1 through the plug 61, the switch I4 closed, and the motor 3i rotated to close the contacts 31-30, there is applied between the electrodes I05 and I06 8. high direct voltage from the charge in thecapacitors 24-26. This voltage is not of sufiicient magnitude to break its own path through the helical envelope I03. The capacitors 24-26 will not discharge through the envelope I03 until an ionizing field has been applied thereto from the high voltage transformer H. The manner in which the ionizing potential is applied to the envelope I03 will now be described with particular reference to Figs. 4 and 5.

As shown in Fig. 5, the electron discharge apparatus comprises essentially a holder I3I and the electron discharge device I02. The holder I3I includes a base I32 having hand grip slots I33 therein. The reflector IN is mounted on the base I52 and has a hole I34 (Fig. 2) near the bottom thereof, through which the electron discharge device I02 passes when installed in the holder MI. The rear portion of the reflector IN is formed into a backward extending cylinder I85, which is fiexedly mounted as shown at I36 in the base I82. The inside of the cylinder I35 forms a recess for the reception of an internally telescoped cylinder I3I, which protrudes forwardly from the cylinder I35 toward the electron discharge device I02. The cylinder I3I constitutes a mounting or support member for a conducting capacitor plate I38, which is transversely secured across the forwardly extending end of the supporting cylinder I3'i. As best seen in Fig. 4, the capacitor plate I36 is in the form of an arcuate portion of a cylinder, so that it may flt closely to, and conform to the configuration of, the transparent cover I04 of the electron discharge device I02.

The outer cylinder I36 has a longitudinal slot Iti in the upper wall thereof, through which passes a set screw I42 threaded into a tapped hole in the mounting cylinder I3I. In this manner the capacitor plate I38 may be adjusted toward or away from the cover I04 by the telescoping of the cylinders I3I and I36, and held securely in an adjusted position by the screw and slot arrangement I42 and III.

Cooperating electrically with the capacitor plate iii is a conductor in the form of a third mounting post I5I, having a loop I52 which en-- compasses the convolutions of the helix I03 and serves to physically support the helix within the cover I04. However, unlike the posts III and II3, the post I5I has no conducting relation to the envelope I03 similar to the electrodes I05 and I06. Instead, the post I5I together with its loop I52 represents a capacitor plate which, with the conducting plate I38, establishes an electrostatic field across a portion of the helical convolutions. This field is suflicient to break down the resistance within the envelope I03, thereby allowing the charge on the capacitors 24-26 to pass from the electrode I06 to the electrode I05, and produce a brilliant dash of actinic light.

Alternating current potential from the transformer M is placed upon the capacitor plates I5I and I30 by grounding the plate I38 through the cylinder support I3I, the cylindrical recess I35, the reflector IN, a. ground connector I6I, a conductor I62, and up to the grounded conductor 65 in the circuit of Fig. 1; and by concorporated in the lens mechanism I2.

heating the other conductor 66 or the high voltage secondary winding 64 to the capacity post I5I, through the plug 61, a conductor III, and the prong I08. Thus when the transformer primary winding 62 is energized by the closing of the camera contacts I8 and I8, the high alternating voltage from secondary winding 64 is applied capacitively across the convolutions of the helical Operation The operation of the photographic apparatus described above is as follows: The switch I4 is closed, thereby energizing primary winding I2, indicator light 5|, relay 56, motor 3i, and the cathode heating circuit of rectifier II. Energize.- tlon of relay 56 opens the capacitor leakage circuit including the resistor 55, and prepares the apparatus for charging of the capacitors 24-26. Motor 3I rotates until the disk 33 has rotated far enough, against the force of spring' 42, to bring contact 31 into engagement with the stationary-contact 38. This energizes relay coil 38, opening the circuit of motor 3i, at the contact 22, and closing the circuit between the rectifier conductor I9 and the high voltage conductor 2i which supplies the capacitors 24-26. Simultaneously the auxiliary contact 53 closes to energize the high voltage indicating light 52.

Which of the capacitors 24-26 is to be connected to the conductor 2I is determined by the position of the bridging member 28 of the switch 21. The briefest flash of light will be produced by the smallest capacitance; in this case only the capacitor 24 is left in the circuit. Conversely the longest flash of light will be produced when all three capacitors are in the circuit. In Fig. 1, switch 21 is so adjusted that

only capacitors

24 and 25 are connected to the conductor 2|, thereby preparing the circuit for a flash of medium length.

With the energization of relay 23, the

capacitors

24 and 25 are charged, and the direct voltage is applied across the electrodes I05 and I06, through the elements 2I, I22, I08, H3, 6, (I06), (I05), II5, I01, I2I,and 44.

The camera operator, having focused the camera II, rotates the shutter setting lever I3 clockwise to the position shown in Fig. 3, where it remains by virtue of the latch mechanism in- This preparatory step, although momentarily closing contacts I8 and I9, does not energize transformer 6I because the foot switch 83 is open. The operator then steps on the switch 83 and presses the thumb button 81. The resulting energization of solenoid trips the shutter release lever I4 and the shutter setting-lever I3, thereby pulling the link 84 to rotate the cam arm I6 counterclockwise.

The closing of the contacts I8 and I9 momentarily applies high voltage alternating current from transformer 6I through the

conductors

65 and 66 to the plug 61.

This momentary voltage is applied from the plug 61 to the conductors I62 and III, and thence across the capacitor plate I38 and the capacitor conductors I5I, I52. The brief electrostatic field thus placed across the convolutions oi the helical envelope I03 lowers the resistance of the discharge path within the envelope sufllciently to allow the charge on the

capacitors

24, 25 to pass from the electrode I06 to the electrode I05, thereby producing a brilliant flash of actinic light.

By means of apparatus constructed in accordance with the principles of this invention, it has been found possible to produce flashes of photographic light ranging from .66 microseconds to 250 microseconds, depending on the capaci-' tance placed between ground and the high voltage direct current conductor 2 I.

It will be understood that this invention may be made and utilized in any suitable shape, size, or arrangement, depending upon the particular electron discharge device to be accommodated, and that various modifications and changes may be made in this invention without departing from the spirit and scope thereof, as set forth in the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed is:

1. A holder for an electron discharge device, comprising a base, a capacitor plate, a mounting member secured to said plate and extending substantially normally therefrom, and means adjustably mounting said member on said base thereby to mount said plate in adjustable relation to an electron discharge device secured in said base.

2. A holder for an electron discharge device, comprising a base having recessed holding means therein, a support member movable in and out of said recess, a capacitor plate secured transversely on the end of said support member adapted to electrically affect an electron discharge device mounted in said base, and means for adjustably securing said support member in said recess thereby to support said plate in adjustable relation to the discharge device.

3. A holder adapted to receive an electron discharge device, comprising a base, a first cylinder secured to said base with the axis thereof extending out from said base, a second cylinder longitudinally slidably mounted in telescopic relation with said first cylinder, a screw and slot connection between said cylinders for adjustably securing them in predetermined relation, and a capacitor plate secured transversely on the end of said second cylinder adapted to be placed in adjustable position with respect to an electron discharge device held in the holder.

4. In combination with an electron discharge envelope having electrodes for conducting a discharge current to said envelope and a holder in which said envelope is mounted, a conductor mounted adjacent said envelope, and a conducting member disposed adjacent said envelope forming, with saild conductor, a capacitor for applying an electrostatic field to said envelope, and means for adjustably securing said member to said holder, thereby holding it in adjustable relation to said envelope.

5. In combination with an electron discharge envelope having electrodes for conducting a discharge current to said envelope and a holder in which said envelope is mounted, a conductor mounted adjacent said envelope, and a conducting plate disposed adjacent said envelope forming, with said conductor, a capacitor for applying an electrostatic field to said envelope, a mounting member secured to said plate and extending away from said envelope, and means for adjustably securing said mounting member to said holder, thereby holding said plate in adjustable relation to said envelope.

6. An electron discharge device comprising an electron discharge envelope, a cover around said envelope, a capacitor conductor in the form of a plate adjustably mounted externally of said cover immediately adjacent thereto, the shape of said plate conforming closely to the contour of the adjacent cover, the mounting for said plate permitting adjustability thereof toward and away from said cover and a complementary capacitor conductor positioned to create, in conjunction with said plate, an electric field within said envelope.

7. Electron discharge apparatus comprising a holder, an electron discharge envelope mounted in said holder, a substantially cylindrical cover mounted around said envelope, a capacitor conductor in the form of a plate formed as a portion of a cylinder having a diameter slightly larger than that of said cover, a mounting member secured to the outer surface of said plate and projecting substantially radially therefrom, means securing said member to said holder and a complementary capacitor conductor positioned to create, in conjunction with said plate, an electric field within said envelope.

8, Electron discharge apparatus. comprising a holder, an electrondischarge envelope mounted in said holder, a substantially cylindrical cover mounted around said envelope, a capacitor conductor in the form of a plate formed as a portion of a cylinder having a diameter slightly larger than that of said cover, a mounting member secured to the outer surface of said plate and projecting substantially radially therefrom, means adjustably securing said member to said holder to permit adjustment of said plate toward and away from said cover and a complementary capacitor conductor positioned to create, in conjunction with said plate, an electric field within said envelope.

RICHARD W. DANIELS.

REFERENCES CITED The following references are of record in the file of this patent: