EP0029523A1 - Miniatur-Fotoblitzlampe und Verfahren zur Herstellung - Google Patents

Miniatur-Fotoblitzlampe und Verfahren zur Herstellung Download PDF

Info

Publication number: EP0029523A1
Authority: EP; European Patent Office
Prior art keywords: envelope; wires; flash; photoflash lamp; lamp according
Prior art date: 1979-11-21
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.): Granted

Application number

EP19800106716

Other languages

English (en)

French (fr)

Other versions

EP0029523B1 (de

Inventor

Andre C. Bouchard

Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

Osram Sylvania Inc

Original Assignee

GTE Products Corp

Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)

1979-11-21

Filing date

1980-10-31

Publication date

1981-06-03

1980-10-31 Application filed by GTE Products Corp filed Critical GTE Products Corp

1981-06-03 Publication of EP0029523A1 publication Critical patent/EP0029523A1/de

1983-10-05 Application granted granted Critical

1983-10-05 Publication of EP0029523B1 publication Critical patent/EP0029523B1/de

Status Expired legal-status Critical Current

Links

238000004519 manufacturing process Methods 0.000 title claims description 6
239000000203 mixture Substances 0.000 claims abstract description 45
239000002245 particle Substances 0.000 claims abstract description 26
QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims abstract description 18
239000007800 oxidant agent Substances 0.000 claims abstract description 13
238000000034 method Methods 0.000 claims abstract description 11
239000012255 powdered metal Substances 0.000 claims abstract description 11
229910052726 zirconium Inorganic materials 0.000 claims abstract description 10
239000004033 plastic Substances 0.000 claims abstract description 9
VKJKEPKFPUWCAS-UHFFFAOYSA-M potassium chlorate Chemical compound [K+].[O-]Cl(=O)=O VKJKEPKFPUWCAS-UHFFFAOYSA-M 0.000 claims abstract description 9
239000000463 material Substances 0.000 claims description 35
238000007789 sealing Methods 0.000 claims description 9
239000011521 glass Substances 0.000 claims description 6
239000004743 Polypropylene Substances 0.000 claims description 4
AXZAYXJCENRGIM-UHFFFAOYSA-J dipotassium;tetrabromoplatinum(2-) Chemical compound [K+].[K+].[Br-].[Br-].[Br-].[Br-].[Pt+2] AXZAYXJCENRGIM-UHFFFAOYSA-J 0.000 claims description 4
-1 polypropylene Polymers 0.000 claims description 4
229920001155 polypropylene Polymers 0.000 claims description 4
229910001487 potassium perchlorate Inorganic materials 0.000 claims description 4
239000011248 coating agent Substances 0.000 claims description 3
238000000576 coating method Methods 0.000 claims description 3
238000002485 combustion reaction Methods 0.000 claims description 3
229910052735 hafnium Inorganic materials 0.000 claims description 3
VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 claims description 3
BZSXEZOLBIJVQK-UHFFFAOYSA-N 2-methylsulfonylbenzoic acid Chemical compound CS(=O)(=O)C1=CC=CC=C1C(O)=O BZSXEZOLBIJVQK-UHFFFAOYSA-N 0.000 claims description 2
230000004913 activation Effects 0.000 abstract description 2
239000000446 fuel Substances 0.000 description 7
239000000843 powder Substances 0.000 description 7
238000005286 illumination Methods 0.000 description 5
229910052782 aluminium Inorganic materials 0.000 description 4
XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 4
230000008901 benefit Effects 0.000 description 4
239000011888 foil Substances 0.000 description 4
QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
229910052751 metal Inorganic materials 0.000 description 3
239000002184 metal Substances 0.000 description 3
239000001301 oxygen Substances 0.000 description 3
229910052760 oxygen Inorganic materials 0.000 description 3
239000000020 Nitrocellulose Substances 0.000 description 2
230000002411 adverse Effects 0.000 description 2
IWOUKMZUPDVPGQ-UHFFFAOYSA-N barium nitrate Chemical compound [Ba+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O IWOUKMZUPDVPGQ-UHFFFAOYSA-N 0.000 description 2
229920001220 nitrocellulos Polymers 0.000 description 2
230000001590 oxidative effect Effects 0.000 description 2
230000008569 process Effects 0.000 description 2
DHEQXMRUPNDRPG-UHFFFAOYSA-N strontium nitrate Chemical compound [Sr+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O DHEQXMRUPNDRPG-UHFFFAOYSA-N 0.000 description 2
ZSLUVFAKFWKJRC-IGMARMGPSA-N 232Th Chemical compound [232Th] ZSLUVFAKFWKJRC-IGMARMGPSA-N 0.000 description 1
QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 description 1
RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
229910052776 Thorium Inorganic materials 0.000 description 1
239000011324 bead Substances 0.000 description 1
230000009286 beneficial effect Effects 0.000 description 1
230000015572 biosynthetic process Effects 0.000 description 1
238000004200 deflagration Methods 0.000 description 1
238000011161 development Methods 0.000 description 1
238000010586 diagram Methods 0.000 description 1
238000007598 dipping method Methods 0.000 description 1
230000009977 dual effect Effects 0.000 description 1
230000000694 effects Effects 0.000 description 1
239000007789 gas Substances 0.000 description 1
231100001261 hazardous Toxicity 0.000 description 1
239000008240 homogeneous mixture Substances 0.000 description 1
239000004615 ingredient Substances 0.000 description 1
238000003780 insertion Methods 0.000 description 1
230000037431 insertion Effects 0.000 description 1
239000006194 liquid suspension Substances 0.000 description 1
230000000873 masking effect Effects 0.000 description 1
229920000609 methyl cellulose Polymers 0.000 description 1
239000001923 methylcellulose Substances 0.000 description 1
235000010981 methylcellulose Nutrition 0.000 description 1
238000012986 modification Methods 0.000 description 1
230000004048 modification Effects 0.000 description 1
230000003287 optical effect Effects 0.000 description 1
238000002360 preparation method Methods 0.000 description 1
238000012545 processing Methods 0.000 description 1
238000005204 segregation Methods 0.000 description 1
239000002904 solvent Substances 0.000 description 1
ZNOKGRXACCSDPY-UHFFFAOYSA-N tungsten trioxide Chemical compound O=[W](=O)=O ZNOKGRXACCSDPY-UHFFFAOYSA-N 0.000 description 1
XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
238000005303 weighing Methods 0.000 description 1

Images

Classifications

- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F21—LIGHTING
- F21K—NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
- F21K5/00—Light sources using charges of combustible material, e.g. illuminating flash devices
- F21K5/02—Light sources using charges of combustible material, e.g. illuminating flash devices ignited in a non-disrupting container, e.g. photo-flash bulb

Definitions

the invention relates to photoflash lamps and particularly to photoflash lamps of the miniature variety (those having an internal volume of about 1.0 cubic centimeter or less). Even more particularly, the invention relates to lamps of this variety which are electrically activated.
Such lamps typically include an all-glass envelope, electrical ignition means including a pair of lead-in wires spacedly oriented within a base of the envelope with each wire having a quantity of primer material located on an end thereof and joined to the other primer material by a linear electrical filament, a quantity of shredded, combustible foil (e. g. , zirconium, aluminum, hafnium, or thorium), and a pressurized, combustion-supporting atmosphere (e, g. , oxygen) within the envelope. Understandably, it is essential that the envelope is hermetically sealed in order to contain the atmosphere and assure operability of the lamp.
electrical ignition means including a pair of lead-in wires spacedly oriented within a base of the envelope with each wire having a quantity of primer material located on an end thereof and joined to the other primer material by a linear electrical filament, a quantity of shredded, combustible foil (e. g. , zirconium, aluminum, hafnium, or thorium), and
one of the primary objects of the instant invention is to provide a new and unique photoflash lamp which eliminates the need for the aforedescribed sealed glass envelope and shredded foil elements, as well as the pressurized atmosphere associated therewith, while still providing an intense light output more than sufficient to meet the requirements of many of today's higher speed films.
the lamp as defined herein is thus much less expensive to manufacture than existing miniature lamps and also has proven both safe and reliable in operation.
Still another object of this invention is to provide a new and unique means for providing electrical ignition of the above lamp.
An even further object of the invention is to provide a method for making a miniature photoflash lamp possessing the aforedefined capabilities.
a miniature photoflash lamp having a light-transmitting envelope, a flash-producing composition located within the envelope, and means for igniting the composition.
the lamp's light output is provided by the ignited flash-producing composition which comprises both a powdered metal and a powdered oxidizer.
the powdered metal e. g. , zirconium
a method for making a miniature photoflash lamp which comprises positioning and sealing electrical ignition means within one end of the tubular member, locating a quantity of a flash-producing composition within the tubular member through a second, open end thereof, and thereafter sealing the second, open end.
a miniature photoflash lamp 10 is shown as including a light-transmitting envelope 13, a flash-producing composition 15 within envelope 13 for providing the light output for lamp 10 upon ignition thereof, and ignition means 17 for igniting composition 15 to provide said output.
miniature is meant a lamp having an envelope with an internal volume no greater than about 1.0 cubic centimeter.
Envelope 13 is preferably cylindrical (tubular), and in one embodiment of the invention possessed an internal diameter of about 0.343 centimeter,-an internal length of about 10.00 centimeters, and a wall thickness of about 0.127 centimeter.
the preferred material for envelope 13 is plastic (polypropylene) which, having the above dimensions, results in the envelope being translucent. It is understood, of course, that other plastic materials and dimensional variations are possible, including those which provide a transparent vessel. It is also possible to use glass as the envelope material.
Flash-producing composition 15 comprises a predetermined quantity of a powdered metal (serving as the fuel) and a predetermined quantity of oxidizer (serving as the oxygen supplier).
the preferred powdered metal material is zirconium while the preferred oxidizer material is potassium chlorate.
Other acceptable oxidizers include potassium perchlorate and sodium chlorate while another acceptable metal is hafnium.
one of the primary features of the instant invention is the use of a relatively large particle size metal powder as a key ingredient of the powdered flash-producing composition (15). It was found that zirconium powders having particle sizes ranging from about 10 to about 150 microns could be successfully used to provide desired light outputs without sacrificing containment of the finished product's envelope. Improvements in color temperature were also attained using these particles, and it was possible to readily adjust flash duration times.
an oxidizer having a particle size within the range of about 70 to about 150 microns. It is understood, however, that smaller sizes (e. g. , 10 microns) could be used without adversely affecting the benefits derived from the present invention. Several successful combinations of the above materials are provided below.
envelope 13 contains an atmosphere of air which in effect serves to support combustion. Permitting air to remain in the envelope during formation thereof eliminates the costly procedures of either extracting such atmosphere (e. g. , to form a vacuum) or injecting same at high pressures, as typically required in known miniature lamps.
the aforedefined fuels when used in plastic vessel lamps, should radiate at color temperatures of at least 4000 degrees K.
the finished lamps of the instant invention were all capable of attaining these desired levels. It was also possible to obtain light outputs approaching 500 lumen seconds and, by varying the fuel-oxidizer ratios, to vary the pulse (flash) duration of the output from about 5 to 30 milliseconds. Specifically, increasing the oxidizer content resulted in flash durations approaching the higher time values while excess fuel material produced short durations.
Use of large particle fuels in an air-containing plastic envelope further permitted employment of large quantities of composition 15, in comparison to existing miniature lamps. For example, it was possible to successfully utilize flash-producing compositions weighing from about 25 to about 35 milligrams in a 1.0 cubic centimeter envelope. Higher ratios (composition : envelope volume) are attainable when using smaller sized envelopes.
Ignition means 17 is shown in FIG. 1 as including a pair of conductive lead-in wires 19 and 21 each having an 0.03 centimeter diameter copper wire cover by a 005 centimeter insulative coating. Wires 19 and 21 are twisted about each other (about 4 turns per centimeter) into the configuration shown and sealed within a bottom (end) portion of envelope 13. Understandably, it is also possible to secure these members within one of the envelope's side walls or within the opposing, upper end. Exposed ends 23 of wires 19 and 21 extend within envelope 13 approximately 0.318 centimeter and include thereon a quantity of primer material 25. As shown, ends 23 are spacedly oriented with portions of primer 25 located therebetween.
a suitable power source e. g. , a piezoelectric element
a typical ignition voltage is about 3000 volts.
the deflagrating primer 25 in turn ignites powdered composition 15. It is preferred that primer 25 be located within composition 15 or protrude slightly therefrom as illustrated in FIG. 1. It is possible to eliminate primer 25 in the present invention and directly ignite composition 15 using the spark generated between ends 23 of wires 19 and 21. In such an arrangement, ends 23 are thus defined as being in operative engagement with composition 15 (e. g. , by being inserted therein).
primer 25 it is preferred, however, to utilize primer 25 in that less energy will be required to achieve ignition of lamp 10.
a primer material successfully used included about 78 percent zirconium powder, 16 percent potassium perchlorate, 4 percent Alon C, and 2 percent nitrocellulose, Another suitable example included 50 percent zirconium, 30 percent potassium perchlorate, 10 percent tungstic oxide, 4 percent Alon C, 4 percent glass beads, and 2 percent nitrocellulose. All of the above percentages are by weight of the mixture. Methyl cellulose acetate was used as a solvent in preparation of both of the defined primers. Application of prime r to the ends 23 of wires 19 and 21 was achieved by dipping these ends into the liquid suspension and withdrawing slowly (e. g., 0. 635 centimeter per second). The coated ends were then sealed within the end of envelope 13 as illustrated. Approximately 0.5 to 1. 0 milligram of primer was utilized in lamp 10.
composition 15 electrically, it is also within the scope of the invention to utilize percussively actuated means for this purpose.
a metal primer tube such as described in U.S. Patent 3,535,063 (Anderson et al) could be employed and project from the bottom end of envelope 13. Deformation of the tube would result in deflagration of the fulminating material therein up through the tube and ignition of composition 15 located within the envelope 13 in a similar manner to that depicted in FIG. 1.
3,535,063 are thus incorporated herein by reference.
the upper portion (approximately 9 centimeters of the envelope's length) of envelope 13 was optically darkened (masked) and the defined light output readings were taken from only the remaining "active" light-transmitting region of the envelope. It is understood from the above that composition 15 occupies this region and that the optically darkened portion thus represents an expansion chamber for gases generated during ignition.
the "active" region emits a relatively large proportion of the lamp's total output due primarily to the beneficial results of using large grain size fuels which assure localized burning. Accordingly, the total light output of the invention will be greater than that indicated below wherein optical masking was used on envelope 13.
Flash-producing composition 15.9 milligrams zirconium powder (particle size: 15-20 microns) and 14.1 milligrams potassium chlorate powder (particle size: less than 74 microns).
Pulse Duration 5-7 milliseconds.
Flash-producing composition 15. 9 milligrams zirconium powder (particle size: 15-20 microns) and 14.1 milligrams potassium chlorate powder (particle size: 74-149 microns).
Illumination 400 lumen seconds.
Pulse Duration 10-12 milliseconds.
Flash-producing composition 15.9 milligram zirconium powder (particle size: 44-74 microns) and 14.1 milligrams potassium chlorate powder (particle size: 74-149 microns).
Illumination 350 lumen seconds.
Pulse Duration 20 milliseconds.
Flash-producing composition 15.9 milligrams zirconium powder (particle size: 44-74 microns) and 14.1 milligrams potassium chlorate powder (particle size: less than 74 microns).
Pulse Duration 20 milliseconds.
Flash-producing composition 15.9 milligrams zirconium powder (particle size: 74-149 microns) and 14.1 milligrams potassium chlorate powder (particle size: less than 74 microns).
Illumination 370 lumen seconds.
Pulse Duration 30 milliseconds.
the aforedescribed dual wire electrical ignition means (including primer) was used to ignite the described flash-producing compositions.
a piezoelectric element served as the requisite voltage source.
zirconium powder had a particle size less than 10 microns (e.g., 3 microns). Ignition of the lamps resulted in rupture of the plastic envelope.
the above lamps were each produced by initially providing a piece of elongated, polypropylene tub ing having opposed (first and second) open ends and the described internal diameter (0.343 centimeter).
Wires 19 and 21 were oriented within the block's aperture to extend within the recessed portion whereupon the polypropylene tubing was lowered about the wiring until engagement was effected between the recess and the tube's first open end.
a small force was then exerted at the opposing, second open end of the tubing such that the first end was pressed against the block and deformed about the contained wiring.
the tubing, now having ignition means 17 secured therein, was removed from the aluminum block and oriented vertically.
the described quantity of flash-producing composition 15 was then dropped (using a funnel) into the upright tubing through the second open end.
the composition fell to the bottom (first end) to surround the extending ends of wires 19 and 21 in the manner shown in FIG. 1.
Positioning of composition 15 can be facilitated by moisture-dampening (e. g., using water) the composition prior to insertion.
dampening resulted in a more homogeneous mixture (less particle segregation) than a simple dry (loose) mixture of the same material, particularly when using the larger, coarser grains.
the tubular members were located in an oven and dried (100 degrees C for about 10 minutes) prior to subsequent processing.
the next step in producing lamps 10 involved sealing the remaining (or second) open end. This process simply involved inserting the second end within the recess of the aforedescribed, heated aluminum block until closure was accomplished and a completed envelope was defined.

Landscapes

Engineering & Computer Science (AREA)
General Engineering & Computer Science (AREA)
Vessels And Coating Films For Discharge Lamps (AREA)
Luminescent Compositions (AREA)

EP19800106716 1979-11-21 1980-10-31 Miniatur-Fotoblitzlampe und Verfahren zur Herstellung Expired EP0029523B1 (de)

Applications Claiming Priority (2)

Application Number	Priority Date	Filing Date	Title
US9660679A	1979-11-21	1979-11-21
US96606		1979-11-21

Publications (2)

Publication Number	Publication Date
EP0029523A1 true EP0029523A1 (de)	1981-06-03
EP0029523B1 EP0029523B1 (de)	1983-10-05

Family

ID=22258178

Family Applications (1)

Application Number	Title	Priority Date	Filing Date
EP19800106716 Expired EP0029523B1 (de)	1979-11-21	1980-10-31	Miniatur-Fotoblitzlampe und Verfahren zur Herstellung

Country Status (4)

Country	Link
EP (1)	EP0029523B1 (de)
JP (1)	JPS5686401A (de)
CA (1)	CA1139578A (de)
DE (1)	DE3065193D1 (de)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
US2277482A (en) *	1940-01-26	1942-03-24	Westinghouse Electric & Mfg Co	Photoflash lamp
US3220224A (en) *	1962-05-25	1965-11-30	Westinghouse Electric Corp	Photoflash lamp
US3751656A (en) *	1972-01-10	1973-08-07	Polaroid Corp	Flexible plastic flash illumination devices with solid pyrotechnic material
FR2216248A1 (en) *	1973-02-06	1974-08-30	Poudres & Explosifs Ste Nale	Pyrotechnic gas-free compsn - comprising cupric oxide and zirconium provides rapid ignition of propergol
US3889347A (en) *	1972-08-07	1975-06-17	Norton Co	Method of making combustible metal flashlamp charges

1980
- 1980-10-31 EP EP19800106716 patent/EP0029523B1/de not_active Expired
- 1980-10-31 DE DE8080106716T patent/DE3065193D1/de not_active Expired
- 1980-11-19 CA CA000365055A patent/CA1139578A/en not_active Expired
- 1980-11-20 JP JP16273080A patent/JPS5686401A/ja active Pending

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number	Priority date	Publication date	Assignee	Title
US2277482A (en) *	1940-01-26	1942-03-24	Westinghouse Electric & Mfg Co	Photoflash lamp
US3220224A (en) *	1962-05-25	1965-11-30	Westinghouse Electric Corp	Photoflash lamp
US3751656A (en) *	1972-01-10	1973-08-07	Polaroid Corp	Flexible plastic flash illumination devices with solid pyrotechnic material
US3889347A (en) *	1972-08-07	1975-06-17	Norton Co	Method of making combustible metal flashlamp charges
FR2216248A1 (en) *	1973-02-06	1974-08-30	Poudres & Explosifs Ste Nale	Pyrotechnic gas-free compsn - comprising cupric oxide and zirconium provides rapid ignition of propergol

Also Published As

Publication number	Publication date
DE3065193D1 (en)	1983-11-10
EP0029523B1 (de)	1983-10-05
CA1139578A (en)	1983-01-18
JPS5686401A (en)	1981-07-14

Legal Events

Date	Code	Title	Description
1981-04-06	PUAI	Public reference made under article 153(3) epc to a published international application that has entered the european phase	Free format text: ORIGINAL CODE: 0009012
1981-06-03	17P	Request for examination filed	Effective date: 19801031
1981-06-03	AK	Designated contracting states	Designated state(s): BE DE FR GB IT NL
1983-05-30	ITF	It: translation for a ep patent filed
1983-08-05	GRAA	(expected) grant	Free format text: ORIGINAL CODE: 0009210
1983-10-05	AK	Designated contracting states	Designated state(s): BE DE FR GB IT NL
1983-10-27	PGFP	Annual fee paid to national office [announced via postgrant information from national office to epo]	Ref country code: NL Payment date: 19831027 Year of fee payment: 4
1983-11-10	REF	Corresponds to:	Ref document number: 3065193 Country of ref document: DE Date of ref document: 19831110
1983-11-30	PGFP	Annual fee paid to national office [announced via postgrant information from national office to epo]	Ref country code: BE Payment date: 19831130 Year of fee payment: 4
1983-12-22	PGFP	Annual fee paid to national office [announced via postgrant information from national office to epo]	Ref country code: DE Payment date: 19831222 Year of fee payment: 4
1983-12-23	ET	Fr: translation filed
1984-08-06	PLBE	No opposition filed within time limit	Free format text: ORIGINAL CODE: 0009261
1984-08-06	STAA	Information on the status of an ep patent application or granted ep patent	Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT
1984-10-10	26N	No opposition filed
1984-10-24	PGFP	Annual fee paid to national office [announced via postgrant information from national office to epo]	Ref country code: FR Payment date: 19841024 Year of fee payment: 5
1984-10-31	PG25	Lapsed in a contracting state [announced via postgrant information from national office to epo]	Ref country code: BE Effective date: 19841031
1985-04-30	BERE	Be: lapsed	Owner name: GTE PRODUCTS CORP. Effective date: 19841031
1985-05-01	PG25	Lapsed in a contracting state [announced via postgrant information from national office to epo]	Ref country code: NL Effective date: 19850501
1985-06-12	GBPC	Gb: european patent ceased through non-payment of renewal fee
1985-06-17	NLV4	Nl: lapsed or anulled due to non-payment of the annual fee
1985-07-02	PG25	Lapsed in a contracting state [announced via postgrant information from national office to epo]	Ref country code: DE Effective date: 19850702
1986-06-30	PG25	Lapsed in a contracting state [announced via postgrant information from national office to epo]	Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19860630
1986-08-22	REG	Reference to a national code	Ref country code: FR Ref legal event code: ST
1988-11-18	PG25	Lapsed in a contracting state [announced via postgrant information from national office to epo]	Ref country code: GB Effective date: 19881118

Publication	Publication Date	Title
US3791302A (en)	1974-02-12	Method and apparatus for indirect electrical ignition of combustible powders
US4059388A (en)	1977-11-22	Photoflash lamp
US2982119A (en)	1961-05-02	Flash lamp
US4382775A (en)	1983-05-10	Miniature photoflash lamp and method of making
US2305561A (en)	1942-12-15	Flash lamp
US3220224A (en)	1965-11-30	Photoflash lamp
EP0029523A1 (de)	1981-06-03	Miniatur-Fotoblitzlampe und Verfahren zur Herstellung
US4315733A (en)	1982-02-16	Photoflash lamp with loose powder composition and method of making
CA1079071A (en)	1980-06-10	Photoflash lamp
US2361495A (en)	1944-10-31	Flash lamp
US3972673A (en)	1976-08-03	Photoflash lamp
US2791111A (en)	1957-05-07	Fulminator for photoflash lamps
US4233023A (en)	1980-11-11	Photoflash lamp having expandable burning volume
US3224236A (en)	1965-12-21	Noble gas flash lamp and laser light source
US3106080A (en)	1963-10-08	Flash apparatus
US3521984A (en)	1970-07-28	Photoflash lamp
US4025285A (en)	1977-05-24	Photoflash lamp
US2475281A (en)	1949-07-05	Delay electric initiator
US3817683A (en)	1974-06-18	Photoflash lamps
US3840324A (en)	1974-10-08	Photoflash lamp
US4381915A (en)	1983-05-03	Filament-type lamp primer and fabrication process
US3674411A (en)	1972-07-04	Photoflash lamp
GB867635A (en)	1961-05-10	Improvements in "flash lamp"
US4421493A (en)	1983-12-20	Method of making photoflash lamp
US4432724A (en)	1984-02-21	Photoflash lamp including improved ignition means