JPS5975233A - Photometric circuit - Google Patents

Photometric circuit

Info

Publication number
JPS5975233A
JPS5975233A JP57186943A JP18694382A JPS5975233A JP S5975233 A JPS5975233 A JP S5975233A JP 57186943 A JP57186943 A JP 57186943A JP 18694382 A JP18694382 A JP 18694382A JP S5975233 A JPS5975233 A JP S5975233A
Authority
JP
Japan
Prior art keywords
level
power source
light emission
strobe light
voltage
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
JP57186943A
Other languages
Japanese (ja)
Inventor
Katsuhisa Niwa
Takahiro Ikeda
Original Assignee
West Electric Co Ltd
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 West Electric Co Ltd filed Critical West Electric Co Ltd
Priority to JP57186943A priority Critical patent/JPS5975233A/en
Publication of JPS5975233A publication Critical patent/JPS5975233A/en
Pending legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03BAPPARATUS 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
    • G03B15/00Special procedures for taking photographs; Apparatus therefor
    • G03B15/02Illuminating scene
    • G03B15/03Combinations of cameras with lighting apparatus; Flash units
    • G03B15/05Combinations of cameras with electronic flash apparatus; Electronic flash units

Abstract

PURPOSE:To project or store automatically a strobe light emission part by generating a difference in brigthness level at which an operation is performed according to the variation state of subject brightness and providing the photometric operation with hysteresis. CONSTITUTION:When a specific voltage is supplied from a power source terminal 1 while the strobe light emission part is at a storage position, a photocurrent flows through resistances 3 and 4 since a switch 10 is off. A comparator 8 compares the level of the voltage drop generated across the resistances 3 and 4 by the photocurrent with the voltage level of a reference power source 9 to lower the subject brightness; and the voltage drop level drops at hand-shake limit brightness to invert the output from H to L. When the strobe light emission part is moved from the storage part to a projection position to turn on the switch 10, the specific voltage applied to the power source terminal 1 is supplied between the base and emitter of a transistor 7, which turns on to form a short circuit across the resistance 4.
JP57186943A 1982-10-25 1982-10-25 Photometric circuit Pending JPS5975233A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP57186943A JPS5975233A (en) 1982-10-25 1982-10-25 Photometric circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP57186943A JPS5975233A (en) 1982-10-25 1982-10-25 Photometric circuit

Publications (1)

Publication Number Publication Date
JPS5975233A true JPS5975233A (en) 1984-04-27

Family

ID=16197432

Family Applications (1)

Application Number Title Priority Date Filing Date
JP57186943A Pending JPS5975233A (en) 1982-10-25 1982-10-25 Photometric circuit

Country Status (1)

Country Link
JP (1) JPS5975233A (en)

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