JPS5734573A - Exposure stabilization device - Google Patents

Exposure stabilization device

Info

Publication number
JPS5734573A
JPS5734573A JP10953080A JP10953080A JPS5734573A JP S5734573 A JPS5734573 A JP S5734573A JP 10953080 A JP10953080 A JP 10953080A JP 10953080 A JP10953080 A JP 10953080A JP S5734573 A JPS5734573 A JP S5734573A
Authority
JP
Japan
Prior art keywords
photocurrent
light quantity
lamps
terminal
optical fiber
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
JP10953080A
Other languages
Japanese (ja)
Inventor
Kiyoto Nagasawa
Masayuki Yamauchi
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 Co Ltd
Original Assignee
Ricoh 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 Ricoh Co Ltd filed Critical Ricoh Co Ltd
Priority to JP10953080A priority Critical patent/JPS5734573A/en
Publication of JPS5734573A publication Critical patent/JPS5734573A/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
    • G03B27/00—Photographic printing apparatus
    • G03B27/32—Projection printing apparatus, e.g. enlarger, copying camera
    • G03B27/52—Details
    • G03B27/54—Lamp housings; Illuminating means
    • G03B27/542—Lamp housings; Illuminating means for copying cameras, reflex exposure lighting

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Exposure Or Original Feeding In Electrophotography (AREA)

Abstract

PURPOSE:To keept the whole exposure always constant, by arranging one terminal of an optical fiber in the position capable of detecting the synthesized light quantity of >=2 lamps, and controlling power supply to the lamps in accordance with the detected light quantity. CONSTITUTION:One terminal 8a of an optical fiber cable 8 is arranged on the original placing glass 1 to be illuminated with fluorescent lamps 2, 3, and the other terminal illuminates the photodiode 9 of a control circuit 10 to produce a photocurrent corresponding to the light quantity received by an original. When the light quantity of the lamps 2, 3 decreases, the photocurrent of the diode 9 drops, and this change is compared with a reference voltage through operation amplifiers 11, 12. When the photocurrent decreases, the difference becomes higher, the impace coefficient D of output pulse of a pulse modulator 13 increases, too, extending a conduction time of a switching circuit 27 and raising lamp powers. Vice versa when the photocurrent is larger, permitting the whole exposure to be kept always constant.
JP10953080A 1980-08-09 1980-08-09 Exposure stabilization device Pending JPS5734573A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10953080A JPS5734573A (en) 1980-08-09 1980-08-09 Exposure stabilization device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10953080A JPS5734573A (en) 1980-08-09 1980-08-09 Exposure stabilization device

Publications (1)

Publication Number Publication Date
JPS5734573A true JPS5734573A (en) 1982-02-24

Family

ID=14512585

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10953080A Pending JPS5734573A (en) 1980-08-09 1980-08-09 Exposure stabilization device

Country Status (1)

Country Link
JP (1) JPS5734573A (en)

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5419871U (en) * 1977-07-11 1979-02-08
JPS5511606A (en) * 1978-07-11 1980-01-26 Hitachi Ltd Photoelectric conversion device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5419871U (en) * 1977-07-11 1979-02-08
JPS5511606A (en) * 1978-07-11 1980-01-26 Hitachi Ltd Photoelectric conversion device

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