JPS5778520A - Electronic flash device - Google Patents

Electronic flash device

Info

Publication number
JPS5778520A
JPS5778520A JP15555080A JP15555080A JPS5778520A JP S5778520 A JPS5778520 A JP S5778520A JP 15555080 A JP15555080 A JP 15555080A JP 15555080 A JP15555080 A JP 15555080A JP S5778520 A JPS5778520 A JP S5778520A
Authority
JP
Japan
Prior art keywords
capacitor
generation
prescribed
conduct
transistor
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.)
Pending
Application number
JP15555080A
Other languages
Japanese (ja)
Inventor
Tadashi Okino
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.)
Canon Inc
Original Assignee
Canon 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 Canon Inc filed Critical Canon Inc
Priority to JP15555080A priority Critical patent/JPS5778520A/en
Publication of JPS5778520A publication Critical patent/JPS5778520A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • G03B15/00—Special procedures for taking photographs; Apparatus therefor

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Discharge-Lamp Control Circuits And Pulse- Feed Circuits (AREA)
  • Stroboscope Apparatuses (AREA)

Abstract

PURPOSE:To prevent the erroneous generation of a light emission stop signal owing to the influence of the junction capacity of photodetectors by providing a control circuit which starts integration after a prescribed time from the start of photometry. CONSTITUTION:On closing of a synchronizing switch 16, flash is started, and Zener voltage of a prescribed level is generated in a Zener diode 85 by receiving the voltage of a capacitor 31, and a dimming circuit A starts operating. This forces a transistor (TR)93 to conduct, thereby short circuiting an integrating capacitor 73. After the short time determined by resistors 89, 95, and a capacitor 91, said TR does not conduct, and the integration of the quantity of light is started. When the integrated value attains a prescribed value, a transistor 77 conducts, thereby stopping the light emission. If it is assumed that there is no TR93, the potential of the point P is determined by the junction capacity of a phototransistor 75 and the capacity of the integrating capacitor at the same instant of generation of the Zener voltage and therefore there is possibility of generation of an error signal.
JP15555080A 1980-11-05 1980-11-05 Electronic flash device Pending JPS5778520A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP15555080A JPS5778520A (en) 1980-11-05 1980-11-05 Electronic flash device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP15555080A JPS5778520A (en) 1980-11-05 1980-11-05 Electronic flash device

Publications (1)

Publication Number Publication Date
JPS5778520A true JPS5778520A (en) 1982-05-17

Family

ID=15608507

Family Applications (1)

Application Number Title Priority Date Filing Date
JP15555080A Pending JPS5778520A (en) 1980-11-05 1980-11-05 Electronic flash device

Country Status (1)

Country Link
JP (1) JPS5778520A (en)

Similar Documents

Publication Publication Date Title
US3999193A (en) Automatic control indication device in an automatic control type electronic flash unit
JPS5756831A (en) Wireless dimming control system
JPS57192932A (en) Interval camera
JPS5492233A (en) Photometric device
JPS5778520A (en) Electronic flash device
US4317621A (en) Exposure control apparatus for use with a camera having electronic flash controlling capability
US4427278A (en) Flash photography system and electronic flash device for use in the system
US4062027A (en) Data exposure device for camera
US4112442A (en) Cameras with electrically controlled exposure for use with electronic flash device
JPS56133723A (en) Control circuit for light emission of flash discharging tube
JPS56109322A (en) Camera
JPS5731008A (en) Sewing machine driving device
JPS5662218A (en) Photographing apparatus
JPS5730820A (en) Strobe tuning device
US4331406A (en) Indicating device for computer type electronic flash unit
SU711525A1 (en) Exposure determining and control device
JPS56166637A (en) Preventing circuit for malfunction of sensor
SU1399595A1 (en) Device for lighting up and checking flame
JPS5511239A (en) Aperture control unit in flash photography
JP3093324B2 (en) Slave flash
JPS56132813A (en) Reset device of integrated circuit
KR880004338Y1 (en) Fan control device
KR840006422A (en) Power supply control circuit
JPS6128184Y2 (en)
JPS5756830A (en) Wireless lamp increasing system