JPS5779923A - Automatic exposure controller of camaera - Google Patents

Automatic exposure controller of camaera

Info

Publication number
JPS5779923A
JPS5779923A JP15625980A JP15625980A JPS5779923A JP S5779923 A JPS5779923 A JP S5779923A JP 15625980 A JP15625980 A JP 15625980A JP 15625980 A JP15625980 A JP 15625980A JP S5779923 A JPS5779923 A JP S5779923A
Authority
JP
Japan
Prior art keywords
value
contents
exposure
counts
converted
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
JP15625980A
Other languages
Japanese (ja)
Inventor
Masabumi Yamazaki
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.)
Olympus Corp
Original Assignee
Olympus Corp
Olympus Optical 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 Olympus Corp, Olympus Optical Co Ltd filed Critical Olympus Corp
Priority to JP15625980A priority Critical patent/JPS5779923A/en
Publication of JPS5779923A publication Critical patent/JPS5779923A/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
    • G03B7/00Control of exposure by setting shutters, diaphragms or filters, separately or conjointly
    • G03B7/08Control effected solely on the basis of the response, to the intensity of the light received by the camera, of a built-in light-sensitive device
    • G03B7/091Digital circuits
    • G03B7/093Digital circuits for control of exposure time

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Exposure Control For Cameras (AREA)

Abstract

PURPOSE:To improve the precision of exposure control by weighting logarithmically compressed information on object luminance and by performing expansion by a value converted into an approximate binary number on the basis of its count value. CONSTITUTION:A signal Vs compressed logarithmically corresponding to the luminance of an object is convertd 18 into pulses so that the exposure value of every pulse has 1/n-stage weight, and every time an n-scale counter CT19 counts the converted pulses up to (n), an m-scale CT20 counts up by one. Further, the contents (l) (<n) of the CT19 are converted 21 into an approximate binary expanded value 2l</2>, which is shifted 22 by (k) digits by the counts (k) (<m) of the CT20; and the contents of a register 22 are transferred to a CT24 in response to a shutter release signal and on the start of exposure operation, the contents of the register 22 are decreased. When the contents of the CT24 goes down to a prescribed value, a shutter is closed. At this time, exposure control is exercised by exposure time which approximates to an expanded value 2<(k+>l</n>).
JP15625980A 1980-11-06 1980-11-06 Automatic exposure controller of camaera Pending JPS5779923A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP15625980A JPS5779923A (en) 1980-11-06 1980-11-06 Automatic exposure controller of camaera

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP15625980A JPS5779923A (en) 1980-11-06 1980-11-06 Automatic exposure controller of camaera

Publications (1)

Publication Number Publication Date
JPS5779923A true JPS5779923A (en) 1982-05-19

Family

ID=15623880

Family Applications (1)

Application Number Title Priority Date Filing Date
JP15625980A Pending JPS5779923A (en) 1980-11-06 1980-11-06 Automatic exposure controller of camaera

Country Status (1)

Country Link
JP (1) JPS5779923A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61149935A (en) * 1984-12-24 1986-07-08 Copal Co Ltd Exposure controller

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61149935A (en) * 1984-12-24 1986-07-08 Copal Co Ltd Exposure controller

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