US3748989A - Electronic flash system - Google Patents

Electronic flash system Download PDF

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Publication number
US3748989A
US3748989A US00204579A US3748989DA US3748989A US 3748989 A US3748989 A US 3748989A US 00204579 A US00204579 A US 00204579A US 3748989D A US3748989D A US 3748989DA US 3748989 A US3748989 A US 3748989A
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US
United States
Prior art keywords
flashtube
electronic flash
capacitor
circuit
flash system
Prior art date
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.)
Expired - Lifetime
Application number
US00204579A
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English (en)
Inventor
I Ban
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.)
Secoh Giken Co Ltd
MIYATA ELECTRIC WORKS Inc
Original Assignee
Secoh Giken Co Ltd
MIYATA ELECTRIC WORKS Inc
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.)
Filing date
Publication date
Application filed by Secoh Giken Co Ltd, MIYATA ELECTRIC WORKS Inc filed Critical Secoh Giken Co Ltd
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Publication of US3748989A publication Critical patent/US3748989A/en
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    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B7/00—Control of exposure by setting shutters, diaphragms or filters, separately or conjointly
    • G03B7/16—Control of exposure by setting shutters, diaphragms or filters, separately or conjointly in accordance with both the intensity of the flash source and the distance of the flash source from the object, e.g. in accordance with the "guide number" of the flash bulb and the focusing of the camera

Definitions

  • ABSTRACT An electronic flash system including a flashtube for producing a controlled quantity of light energy, a plurality of capacitors in which is stored electrical energy to be translated into the light energy in the flashtube and which are to be selectively coupled to the flashtube, a monitoring circuit for generating a signal when the quantity of the light energy produced by the flashtube has reached a predetermined value, bypass means for causing the electrical energy discharged from alcapacitor coupled to the flashtube to bypass the flashtube in response to the signal generated by the monitoring circuit, and a control circuit becoming operative when the electrical energy discharged from the capacitor that has been coupled to the flashtube falls short of a desired quantity of light energy to be produced and selectively coupling the rest of the capacitors to the flashtube until the desired 'quantity of light energy is emitted thereby.
  • This invention relates to an electronic flash system for photographic and other applications, and more particularly to an improved electronic flash system capable of automatic control of the quantity of light energy produced by a flashtube provided therein.
  • the reference numerals 9, 10 and 11 given in FIG. 3 indicate the output terminals of the DC power supply means of FIG. 1.
  • amanuallyturnable knob 160 is secured with a shaft 161 and'a dial 162 which is marked with an index 163.
  • Another dial 164, attached to the camera body, is marked with'an index 165.
  • the shaft 161 is coupled with a shaft'167 of housing 166 containing the aforesaid variable resistor 159, so that the resistance of this variable resistor 159 is to be changed by the manual turn of the knob 160.
  • a magnet 168 is attached to a yoke 169 of the aforesaid meter 154, and a movable coil 170 is secured with a pointer 171.
  • the photoelectric element 62 in the monitoring circuit of FIG. 4 or 9 is turned so as to be radiated directly by the flashtube 23.
  • Variable resistor 153, photoconductor 152, power supply 155 and meter 154 combine to make up the mentioned semiautomatic exposure setting mechanism as in the precedingly described embodiment of FIG. 9. Only the changeover switch 156 of FIG. 9 is absent here. For taking pictures by daylight, a proper setting of shutter speed causes a corresponding change in the resistance of the variable resistor 153. Of the T.T.L.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Stroboscope Apparatuses (AREA)
  • Exposure Control For Cameras (AREA)
US00204579A 1970-12-05 1971-12-03 Electronic flash system Expired - Lifetime US3748989A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP45107198A JPS4817334B1 (enrdf_load_stackoverflow) 1970-12-05 1970-12-05

Publications (1)

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US3748989A true US3748989A (en) 1973-07-31

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ID=14452952

Family Applications (1)

Application Number Title Priority Date Filing Date
US00204579A Expired - Lifetime US3748989A (en) 1970-12-05 1971-12-03 Electronic flash system

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US (1) US3748989A (enrdf_load_stackoverflow)
JP (1) JPS4817334B1 (enrdf_load_stackoverflow)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4021824A (en) * 1974-06-07 1977-05-03 Canon Kabushiki Kaisha Flash light photographic system for camera
US4105929A (en) * 1976-06-30 1978-08-08 Gte Sylvania Incorporated Shunt triggered flashtube having safety feature
US4192597A (en) * 1978-10-27 1980-03-11 Polaroid Corporation Photographic apparatus for selectively actuating a pulsable electronic strobe
US5264895A (en) * 1991-08-23 1993-11-23 Konica Corporation Flash lighting circuit

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4021824A (en) * 1974-06-07 1977-05-03 Canon Kabushiki Kaisha Flash light photographic system for camera
US4105929A (en) * 1976-06-30 1978-08-08 Gte Sylvania Incorporated Shunt triggered flashtube having safety feature
US4192597A (en) * 1978-10-27 1980-03-11 Polaroid Corporation Photographic apparatus for selectively actuating a pulsable electronic strobe
US5264895A (en) * 1991-08-23 1993-11-23 Konica Corporation Flash lighting circuit

Also Published As

Publication number Publication date
JPS4817334B1 (enrdf_load_stackoverflow) 1973-05-29

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