DE2204965A1 - Photo flash lamps - Google Patents

Description

Dr. rer. nat. Horst pupil PATENT ADVOCATE

Frankfurt / Main 1, Feb. 1 1972 Niddastraße 52 WK. / Hey

Telephone (0611) 237220 Postscheck-Account: 282420 Frankfurt M.

Bank account: 225/0389 Deutsche Bank AG, Frankfurt'M.

1942-LD-6OO9

GENERAL ELECTRIC COMPANY

1 River Road Schenectady, M.Y "/ti.S.A.

Photo flash lamps

The invention relates to an improved photoflash lamp in miniature design, which is generally of the all-glass type and the base of which is a filling of fibrous combustible material consisting essentially of HafnLum and a <\ fxr. for combustion, for example oxygen, under hr-hom Iirunk.

209833/1077

There are commercially available miniature type photo flash lamps known, such as the well-known ALlglas-Photo-

Type AOl flash lamp. This used frayed zirconium foil and oxygen L in a glass bulb made of clear glass with a volume of less than 2 cm ', which is completely safe in operation, ie it is non-destructive. These generate a total amount of light in the range of 6500 lumen seconds without cubic centimeters of the bulb volume. Such lamps are described, for example, in U.S. Patent 2,982,119. ^ ⁿ the subsequent development, such miniature photoflash lamps have been improved while maintaining safety of operation. In the case of lamps for use in a known lightning cube, for example, these lamps were set up for an integrated or summed light output of around 7,000 lumen seconds per cubic centimeter of the lamp volume. In the case of the photoflash lamps commercially available under the type designation AG3, an even higher total light output power of around HfOO lumen seconds per cubic centimeter of the lamp volume was achieved. A further gain in the light output power per unit volume while maintaining safe lamp operation was achieved with such all-glass miniature photoblite lamps by using frayed zirconium foil as a filling in addition to oxygen gas under high pressure in conjunction with a fiorosil ikatgiaskolben. which has a low! ■ Jcirm expansion coefficient and high warmer, .-? [-, t'iu! ity according to the US patent; ■ $. Wh, τR ^r ., Such Fhotobl ί Xz lamperi boülteen a summed light compensation. · .JI:; t: ung of at least l ' ^{) C} ) 00 lumen seconds per cubic cent in * t> r · d · .-, · piston volumeiii. Although for the fibrous, Vi-rbr-ririV -rr: · "" iferial r.oU-htr vorbt'lr'uinten Phot ob 1. It ζ lamps in Fin 1 atur-m ;; riihrun.i · ? ■ irkon ium verviend.'t, other Brennf-'T « i-lrd t't'i i 1 ien like A! umlniuin, Unfniurn and Thorium or ■■ • i->: 'r, etn' \ .! .ί gen wor.K'n as fiber-shaped; he creates lights. !. f'nl-er-ti J. f'iSt · dc: z \ <iv.wn accordance del 'aIJgemeinen Descr i Imrig in VV - ^v'; t *: ent l. 'λ ^ .6 / ^ l.

BATH ORIGINAL

209833/1077

The present invention achieves a considerable further increase in the total light output power of miniature flash lamps while maintaining complete operational reliability. Ks are strong, evenly distributed fillings of thread-like hafnium used as a combustible material in connection with an Olas piston from a high degree of heat! solid material with a low coefficient of thermal expansion, which also gives an excellent seal with the ignition means. In addition, increased filling pressures are used for the gas that maintains the combustion in order to obtain a flash lamp which results in a multiple increased total light output power per cubic centimeter of the bulb volume in the range of about 1 ^ 00 lumen seconds / cm - J> 2 500 Im s / cm and in some cases an even higher light output.

1 shows a view of an all-glass photoflash lamp according to FIG the invention; with one evenly distributed in the highest water filling made of a thread-like hafnium material.

Fig. 2 shows an all-glass lamp according to the invention similar to Fig. 1, but with a base according to the lamp of the type AOl.

Fig. ~ *> Zeirt> Mne Allglaslampe according to the invention similar * Fig. 1 · ηit of ignition in the form of a kind of percussion primer Cperc'K'.ri ve tire ignition).

FIG. H shows an all-glass lamp according to the prior art using a filling made of fibrous material.

FIG. * Shows the design of the filamentary tubes of combustible material which are used in the Plitz lamps of FIGS . ^1-7. can be used and which, according to one aspect of the present invention, are large or curved.

209833/1077 BATH ORIGINAL

Fig. 6 shows a known lightning cube shape in which lamps according to Figures 1-3 are used.

Fig. 7 gives a curve comparing the greatly increased summed Light output power as achieved by photoflash lamps according to the invention in comparison with previously known flash lamps is obtained.

Fig. 8 shows the curves of the course of the instantaneous light output power based on the inner bulb volume for previously known lamps and flash lamps according to the invention.

In Fig. 1, the flashlamp 10 includes a sealed one Piston 11 made of clear drawn glass tube with an internal volume of less than 1 cubic centimeter. This piston is on closed at one end by an integral flattened portion or pinch seal 12 and at the other end by a Suction tip 13. Fibers made of combustible material 14 are distributed inside the lamp bulb and react when the lamp is ignited Lamp chemically with a combustion sustaining gas in the bulb, for example oxygen, to produce a flash of light obtain.

The lamp is equipped with a suitable device for starting the flash. In the case of the lamp according to FIG. 1, this includes this device a pair of lead wires 15, which are inserted in the pinch foot 12 in a sealed manner and attached to their inner Terminated by a filament 16 in the form of a short length of fine tungsten wire about 0.015 mm in diameter (0.6 mil) are connected. Beads of fulminating or ignition material 17 are on the ends of the supply lines 15 as coating and are in contact with the filament 16. When the filament is operated by electric current, are ignited by the heat of the filament and solve the

209833/1077

the thread-like combustible material 14 burns out. An isolating one Support part 18, for example a glass bead, connects the two supply lines 15 to one another and supports their mounting inside the piston. The extended ends 19 of the leads extend from the pinch seal 12 to outside and support the mounting of the flash lamp in a conventional flash cube 20 according to FIG. 6 and serve as electrical Connection line to the flash lamp.

Fig. 2 shows a flash lamp design according to the type AGl, in which the pinch seal 12 can be enlarged and is equipped with a transverse groove 21. The ends of the leads 19 are included bent back over the pinch foot and their free ends are returned and embedded in the pinch foot and result as Effect of a lamp base for holding the flash lamp in a base part. Such a base construction is in the U.S. Patent 3,016,727.

Another form of ignition device ^, h. an ignition device according to the so-called percussion fuse type is shown in FIG. A rod 22 carries a coating 23 made of an ignitable by impact Detonator material on part of its length and is mounted centrally in a deformable metal tube 24 which is attached to a The end of the lamp envelope 10 protrudes and is inserted there in a sealed manner. The tube 24 is closed at its outer end. The lamp according to Figure 3 is flashed by striking the tube 24 with a hammer or a spring in one area opposite to the igniter material 23 is struck to ignite this material. This then becomes out of the open inner end of this tube? 4 ejected into the lamp envelope to ignite the combustible material in the lamp. Lamps The type "with" detonators can be used in a lightning cube if per se known separate constructions for mechanical operated spring hammers used to flash the lamps will.

2 0 9 8 3 3/1 Q 7 1

Other devices can optionally be used for igniting the flash lamps, for example piezoelectric ones known per se Crystals or lasers.

Photo flash lamps of the general external shape according to FIGS. 1, 2 and 3 are known per se. According to the teaching of the present In the invention, the execution of the construction and the basic parameters are modified and combined in a novel way to surprisingly create flashlamps with greatly increased total summed light output for a given size of the lamp envelope. The increases are on the order of a factor of 2 or more. The technical teaching given here can be used particularly advantageously on the newer all-glass miniature flash lamps and flash cubes, in which the internal volume of the lamp envelope is less than 1 cubic centimeter.

In a preferred embodiment of the present invention and for the greatest possible use of the advantages of the invention, a lamp vessel 11 with a volume of less than one cubic centimeter is made of a borosilicate glass with a low coefficient of thermal expansion in order to provide increased strength for holding the bulb together and for resistance to the thermal and mechanical shock such as occurs when the lamp is flashed. In addition, an excellent hermetic seal is obtained with the lead wires 15. The lead wires 15 carrying the ignition device are made of a metal or an alloy which has essentially the same coefficient of thermal expansion as the glass. For example, a suitable supply line can be made from an iron, nickel, kot-ai t alloy. A suitable glass is i <- aev.i o ^ en p: e ^r \ ann {·: \ · US patent ι 506 385. described. This Olan * rz.-y ^ _e \ _: -. ; .r v ---: it ~ borrowed from the following components in -ic; ':, an;: er;,. They range from 60 to 75% by weight of CdO ₂ , 10 to 25 % by weight. _: p. ^, 1-10 oew.-fl Al _n O-, 4 - 10 wt. Oesamt ^ lk-li-Oxyd? im <i 0-5 wt. -35 BaO.

209823/1077

The glass has an average coefficient of linear

ο —7

Thermal expansion between 0 and 300 C in the range of about 40 ΊΟ- -50 10 per degree C. The wall thickness of the glass is not dependent on the composition of borosilicate glass used _β Examples of suitable wall thicknesses of the glass tube from which the piston are made 11 , range between about 0.25 - 1.25mni (10 mils - 50 mils).

In addition to the use of a borosilicate glass tube with the properties mentioned for the piston, a combustible filling 14 is made from Hafnium or an alloy applied, which we sent borrowed from Hafnium consists. The thread-like material 14 can in itself be cut in a known manner from hafnium foil in order to produce a fiberized foil. The thickness of the hafnium foil is there in the range between 0.013 now - 0.04 mm (0.5 - 1.5 mil) and the cut width of the individual fibers is in the range of about 0.013mm - 0.075mm (0.5-3 mils). The amount of in the lamp bulb Fibrous combustible material filled in is in the range of 60-200 mg per cubic centimeter of the internal lamp volume .

The distribution of the frayed hafnium material in extraordinary support more uniformly and tightly over the interior of the piston, as shown in Figures 1, 2 and 3 the fibers are sharply kinked or crumpled along their length at acute angles on the order of 60 °. For example a fiber length of about 10 cm is kinked with 20 - 40 sharp kinks at intervals of about 3 mm (1/8 inch) are arranged along the length of the fiber. The wrinkling occurs after the individual thread-like fibers are cut out of the sheet-like film material, and before the introduction of the Fibers in the lamp envelope.

Give the sharp bends or wrinkles in the fibers these hair dryers a tightly clumped or wrinkled

209833/1077

see as shown at 25 in FIG. When they are in a flask are filled, the wrinkled fibers form a point contact with the inner wall of the piston according to Figures 1, and 3 · This is a clear difference to the fiber shapes with relatively large open loops and slight bends, which lie against the piston wall over considerable lengths, As can be seen, for example, from the illustration in FIG. 4 at 26 for previously known metal fillings of previously known lamps is.

As a result of the above-described buckling or curling, the restraining or quenching effect is related to the piston wall the rate of combustion when flashing the lamp is reduced and the efficiency of the combustion is increased with increased Light output power. Furthermore, the even distribution and filling density of the foil makes up what is made up of the sharply bent and crimped fibers results in a better oxygen reaction in the whole bulb when flashing and the combustion runs at a constant speed through the entire volume of the combustible material. It is believed that with fibers in crimped form, a reduced self-absorption of the light generated by the thread-like material inside the Piston is present and more usable light is emitted when flashing.

Before the lamp bulb is melted shut, a gas that maintains combustion, for example oxygen, is introduced in such quantities and at such a pressure that. 80-10% of that amount of gas is available which is required when the lamp flashes for a stcL ^ chiometric chemical reaction with the thread-like material 14 made of hafnium on the basis of an idealized chemical reaction equation Hf + 0_ = HfO ". Such gas pressures are in the range of about 8 to ⁷ O atmospheres. In the case of hafnium, takes place over a period of

209833/1077

Combustion comparatively 5-10 milliseconds after ignition slowly and indeed it progresses in proportion as it does chemical reaction between the high molecular weight hafnium and the oxygen accelerates. During the acceleration of the combustion it favors the finely kinked or crinkled State of the pasers the occurrence of a very uniform and high speed of the chemical reaction and thus results in an unusually high light output power during the total lamp life. The result is the instantaneous light output power per unit of lamp volume for the invention Lamps are quite tight for a period of about 13 milliseconds after actuation of the lamp filament 16 the curve shape of known flash cube lamps. This is in the curve of Figure 8 reproduced, which is designated by lamp type A and representative of a flash lamp according to the invention is. This means that the flash lamps according to the invention are suitable for use with types of cameras which have the operating characteristics need previously known, commercial flash lamps, for example the flash cube, the course of which Light output power is shown in Figure 8.

The hafnium metal itself and the hafnium oxide formed during flashing have boiling points of about 5 ¹ JOO ⁰ at atmospheric pressure. Oxygen reaction is maintained in the interior of the borosilicate glass bulb with high fillings or loads, and with photoflash lamps in commercial production a greatly increased light output results without bursting the bulb. The photoflash lamps made in accordance with the present invention provide a total or integrated light output of at least 14,000 lumen seconds per cubic centimeter of lamp volume, and in some cases up to a value

from 3? .500 in s / cm.

209833/1077

220A965

Many thousands of photoflash lamps are made in accordance with the invention and successfully flashed with sufficient security. Design data and results were used as shown in the table below. These lamps used combustible material made from hafnium filaments and the examples are summarized in four groups as type A, B, C and D lamps in the table. The specified light output powers represent values without color correction coatings.

Approximate inner polienge gas pressure light emission wall thickness volume weight in mg in Atmos- in Im s / cm "L ¹ IH? ÜL JIU-ULL- In cm ρ här

A 0.75 (30) 0.55-0.65 42 - 52 10 - 12 14 000 -

17,000 (medium 15,500)

B 0.75 (30) 0.3 -0.35 2P - 36 13 - 17 17,000 -

21,400 (medium 19,400)

C 0.75 (30) 0.3 -0.35 42 - 46 17 - 20 21,800 -

26,600 (medium

24,200)

D 0.83 (33) 0.22-0.26 36 - 44 20 - 26 26,500 -

32,500 (medium 29,500

As an additional measure to prevent the glass bulb from cracking when the lamp flashes, the bulb is coated with a heat-resistant coating by dipping, spraying or otherwise provided with great strength, for example with a cellulose acetate lacquer. In suitable cases, the coating can be coated with

209833/1077

a coloring material can be provided in order to filter or correct the radiation emitted when the lamp is flashed and to obtain a correct color correction for the photographic film to be exposed in a manner known per se.

7 shows, in the form of a curve, the time course of the greatly increased light output of the novel all-glass lamps according to the invention in a miniature version in the form of curves of the integrated light output power per cubic centimeter of the lamps of groups A, B, C and D in comparison with conventional lamp types No. 5 , M3, AGl and flash cube lamps. All lamps were measured without the presence of a colored lacquer or colored coatings or shields to correct the emitted light. As the curves show, there are different values for the total light output in lumens per second per cubic centimeter of the bulb volume for the various lamp types.

Integrated

Lm s / cm

at 40 milliseconds,

Lamps 5 A. Summed up
Lm s / cm ''
after 25 milliseconds. Lamp no. B. 625 M3 C. 2,300 AGl Lightning cube η 5,000 Lamp type 6,600 Lamp type 12,500 Lamp type 16,500 Lamp type 20,500 21,000

800 2,700 6,550

7,400 15-500

19,400

24,200 29.5ΟΟ

Therefore, according to the invention, photoflash lamps can be produced which emit a significantly higher light output per unit of the bulb volume result with excellent safety of the product. In particular, the result here as an embodiment for the Rr-

209833/1077

The flash lamps described in the invention produce a light output per unit of the bulb volume that is about two to five times as high as it has so far been achieved with previously known flash lamps. In the description and claims, the term "piston" is used as such to understand that this is understood to be a bulb, which is optionally depending on the design of the flash lamp in may or may not be provided with a covering that envelops and holds the lamp together in a manner known per se. In In both tables, the total summed light output of the flash lamps was given for 40 milliseconds. This flash duration corresponds essentially to the total usable light output of the lamps, although according to FIG. 7 it can be seen that a very slight increase in light for photographic purposes still for a further 10 seconds up to a total duration of about 50 milliseconds is available.

209833/1077

Claims (1)

- 13 patents Flash lamp, characterized in that it comprises: a translucent glass bulb with a thermal expansion - 7 -7 Thermal coefficients of 40 x 10 'to 50 x 10' per degree C and a volume of less than 1 cm, dispersed in the flask, frayed, combustible material in an amount in the range between 28 and 52 mg, which contains hafnium, in the combustion entertaining gas in the flask in an amount of 80 % to 150 % of the stoichiometric amount, which is required for the chemical reaction with the combustible material and an ignition device to ignite the combustible fibrous material and through the lamp when flashing a total light output between 14,000 and 32,500 lumen seconds per cubic centimeter of the piston volume can be generated. ?. Flash lamp according to claim 1, characterized in that the fibrous, combustible material is finely crimped with sharp kinks at a large number of points closely spaced along the length of the pasers. Z. flash lamp according to claim 1 or 2, characterized in that the bulb volume is in the range from 0.55 to 0.65 cnr, the amount of combustible material is in the range from 42 to 52 mg, the amount of the combustion sustaining gas in Ranges from 10 to 12 atmospheres and the total light output per cubic centimeter of the bulb volume is between 14,000 and 17,000 Im s. 4. Flash lamp according to claim 1 or 2, characterized ge Y e η η ζ f 1 ch η et that the bulb volume in the area 209833/1077 - 11 »- from 0,? up to 0.35 cm, the amount of combustible material In the range of 28 to 36 mg, the amount of the burn is entertaining gas is between 13 and 17 atmospheres and the total light output per cubic centimeter of the Flask volume is between I7,000 and 21,400 Im s. 5. flash lamp according to claim 1 or 2, characterized that the piston volume is in the range 0.3 to 0.35 cm- the amount of combustible material between 42 and 46 mg is the amount of the burn entertaining gas is between 17 and 20 atmospheres and the total light output per cubic centimeter of the piston volume between 21.POO and? 6.66O Im s is. 6. flash lamp according to claim 1 or 2, characterized in that the bulb volume between 0.22 to 0.26 cm - and the amount of combustible material in the range 36 to 44 mg, the amount of the combustion entertaining gas is between 20 and 26 atmospheres and the summed light output per cubic centimeter of the piston volume is between 26,500 and 32,500 Im s. 209833/1077