JPS5754823A - Analogue-digital conversion circuit for illumination photometer - Google Patents

Analogue-digital conversion circuit for illumination photometer

Info

Publication number
JPS5754823A
JPS5754823A JP13113380A JP13113380A JPS5754823A JP S5754823 A JPS5754823 A JP S5754823A JP 13113380 A JP13113380 A JP 13113380A JP 13113380 A JP13113380 A JP 13113380A JP S5754823 A JPS5754823 A JP S5754823A
Authority
JP
Japan
Prior art keywords
power source
circuit
inverter
control
constitution
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.)
Granted
Application number
JP13113380A
Other languages
Japanese (ja)
Other versions
JPS6334968B2 (en
Inventor
Noboru Tonegawa
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.)
Ricoh Elemex Corp
Original Assignee
Ricoh Elemex 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.)
Filing date
Publication date
Application filed by Ricoh Elemex Corp filed Critical Ricoh Elemex Corp
Priority to JP13113380A priority Critical patent/JPS5754823A/en
Publication of JPS5754823A publication Critical patent/JPS5754823A/en
Publication of JPS6334968B2 publication Critical patent/JPS6334968B2/ja
Granted 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
    • G03B7/00—Control of exposure by setting shutters, diaphragms or filters, separately or conjointly
    • G03B7/08—Control 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
    • G03B7/091—Digital circuits

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Indication And Recording Devices For Special Purposes And Tariff Metering Devices (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)
  • Analogue/Digital Conversion (AREA)

Abstract

PURPOSE:To simplify a circuit constitution, by a method wherein an electric potential of a capacitor, whose charge and discharge are controlled by an inverter via an illuminance sensor, is compared by two differential comparators having different reference voltages into which a power source is branched. CONSTITUTION:Through the control of charge and discharge of a capacitor 3, connected in series to an illuminance sensor, by means of an inverter 1, the electric potential is produced into inputs of differential comparators COM 1 and 2, and voltages having different levels, into which a power source voltage VDD is branched, are produced into a reference voltage. Through the control of a flip-flop FF, combined with the control of the inverter, by means of the outputs of the two comparators, a digital output, proportioning to a quantity of light from an output terminal T3, is generated. This eliminates the dependence on the power source voltage VDD, simplifies a circuit constitution without the need for a high-precise reference voltage generation circuit and an operational amplifier, and facilitates the formation of a circuit into LSI.
JP13113380A 1980-09-20 1980-09-20 Analogue-digital conversion circuit for illumination photometer Granted JPS5754823A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP13113380A JPS5754823A (en) 1980-09-20 1980-09-20 Analogue-digital conversion circuit for illumination photometer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP13113380A JPS5754823A (en) 1980-09-20 1980-09-20 Analogue-digital conversion circuit for illumination photometer

Publications (2)

Publication Number Publication Date
JPS5754823A true JPS5754823A (en) 1982-04-01
JPS6334968B2 JPS6334968B2 (en) 1988-07-13

Family

ID=15050751

Family Applications (1)

Application Number Title Priority Date Filing Date
JP13113380A Granted JPS5754823A (en) 1980-09-20 1980-09-20 Analogue-digital conversion circuit for illumination photometer

Country Status (1)

Country Link
JP (1) JPS5754823A (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010016449A1 (en) * 2008-08-08 2010-02-11 Semiconductor Energy Laboratory Co., Ltd. Photoelectric conversion device and electronic device having the same

Also Published As

Publication number Publication date
JPS6334968B2 (en) 1988-07-13

Similar Documents

Publication Publication Date Title
JPS55611A (en) Constant current circuit
JPS57173220A (en) Comparator circuit
JPS56168168A (en) Window comparator circuit
KR840003932A (en) Inverter that converts raw material voltage into AC voltage
GB2061645B (en) Power supply system
JPS5515056A (en) Electronic watch
JPS5590139A (en) Substrate bias generating circuit
JPS5550733A (en) Saw tooth wave generation circuit
JPS5367848A (en) Output voltage compensating circuit for dc power source
JPS56100514A (en) Delay circuit
JPS566479A (en) Semiconductor integrated circuit
SU1273818A1 (en) Device for measuring ratio of two voltages
JPS6459264A (en) Image forming device
JPS56103537A (en) Level converting circuit
JPS6444516A (en) Power supply circuit
JPS5544982A (en) Frequency-voltage converter
JPS5415686A (en) Photoelectric converting device
JPS56154632A (en) Photoelectric conversion circuit
SU766012A1 (en) Transistorized switch
JPS5511658A (en) Electronic relay unit
JPS57159128A (en) Photodetection circuit device
SU868787A1 (en) Transistor simulating device
JPS56147515A (en) Voltage controlled type oscillator
JPS5614926A (en) Photoelectric conversion circuit
JPS57122668A (en) Booster circuit