JPS55542A - Light quantity control unit - Google Patents

Light quantity control unit

Info

Publication number
JPS55542A
JPS55542A JP113179A JP113179A JPS55542A JP S55542 A JPS55542 A JP S55542A JP 113179 A JP113179 A JP 113179A JP 113179 A JP113179 A JP 113179A JP S55542 A JPS55542 A JP S55542A
Authority
JP
Japan
Prior art keywords
light
photo detector
led
control unit
decreases
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
JP113179A
Other languages
Japanese (ja)
Inventor
Yoshihiro Nakamura
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.)
Minolta Co Ltd
Original Assignee
Minolta 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 Minolta Co Ltd filed Critical Minolta Co Ltd
Priority to JP113179A priority Critical patent/JPS55542A/en
Publication of JPS55542A publication Critical patent/JPS55542A/en
Pending legal-status Critical Current

Links

Landscapes

  • Exposure Or Original Feeding In Electrophotography (AREA)

Abstract

PURPOSE:To miniaturize the light quantity detecting part without limiting the installation position of a photo detector by receiving the light of the sub light source which is driven by the electric power corresponding to the electric power for light source with the photo detector and applying the receiving light signal thereof to the control unit thereby controlling the quantity of light. CONSTITUTION:The LED 31 of the light quantity detecting part 30 is parallel-connected to an exposure lamp 10 whose emission quantity is controlled by ignition phase control of an SCR 20 and is let to emit light at the quantity proportional to the terminal voltage of the lamp 10. A photo detector 32 receives the light of the LED 31 and sends its output signal to a control unit 40. When the supply voltage decreases, the emission quantity of the exposure lamp 10 and LED 31 decreases. The incident light quantity to the photo detector 32 decreases and its resistance value increases, hence the base-emitter voltage of a transistor 47 increases and the charging current to a capacitor 52 flowing through a resistance 51 and the emitter- collector of the transistor 47 increases. This results in the shortened time until a PUT 53 conducts, expedited ignition phase of the SCR 20, increased power supply to the exposure lamp 10 and increased emission quantity.
JP113179A 1979-01-08 1979-01-08 Light quantity control unit Pending JPS55542A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP113179A JPS55542A (en) 1979-01-08 1979-01-08 Light quantity control unit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP113179A JPS55542A (en) 1979-01-08 1979-01-08 Light quantity control unit

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
JP50007567A Division JPS5182630A (en) 1975-01-16 1975-01-16

Publications (1)

Publication Number Publication Date
JPS55542A true JPS55542A (en) 1980-01-05

Family

ID=11492882

Family Applications (1)

Application Number Title Priority Date Filing Date
JP113179A Pending JPS55542A (en) 1979-01-08 1979-01-08 Light quantity control unit

Country Status (1)

Country Link
JP (1) JPS55542A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6113800U (en) * 1984-06-29 1986-01-27 信一 久末 Fall prevention device for cylinder ladders
JPS6450599U (en) * 1987-09-25 1989-03-29

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4911347A (en) * 1972-05-24 1974-01-31

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4911347A (en) * 1972-05-24 1974-01-31

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6113800U (en) * 1984-06-29 1986-01-27 信一 久末 Fall prevention device for cylinder ladders
JPH0430316Y2 (en) * 1984-06-29 1992-07-22
JPS6450599U (en) * 1987-09-25 1989-03-29

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