JPS5737342A - Variable magnification copying machine - Google Patents

Variable magnification copying machine

Info

Publication number
JPS5737342A
JPS5737342A JP11255080A JP11255080A JPS5737342A JP S5737342 A JPS5737342 A JP S5737342A JP 11255080 A JP11255080 A JP 11255080A JP 11255080 A JP11255080 A JP 11255080A JP S5737342 A JPS5737342 A JP S5737342A
Authority
JP
Japan
Prior art keywords
aperture
lens systems
drum
magnification
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.)
Pending
Application number
JP11255080A
Other languages
Japanese (ja)
Inventor
Kimio Nakahata
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.)
Canon Inc
Original Assignee
Canon Inc
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 Canon Inc filed Critical Canon Inc
Priority to JP11255080A priority Critical patent/JPS5737342A/en
Publication of JPS5737342A publication Critical patent/JPS5737342A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00—Apparatus for electrographic processes using a charge pattern
    • G03G15/04—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
    • G03G15/041—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material with variable magnification
    • G03G15/0415—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material with variable magnification and means for controlling illumination or exposure

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Exposure Or Original Feeding In Electrophotography (AREA)
  • Variable Magnification In Projection-Type Copying Machines (AREA)

Abstract

PURPOSE:To prevent the unevenness in the brightness of a copying image from fluctuating at every changing of magnification by disposing a light shielding means having a middle stop aperture shape along the moving direction of lenses in proximity to the lens face and changing the aperture shape according to the change in the magnification. CONSTITUTION:The projected images of the parts (a), (b), (c) of an original 1 placed on an orginal plate 5 are formed as electrostatic latent images on a photosensitive drum 4 by lens systems 2, 3 moving along rails 9. At this time, differences in illuminances on the drum 4 are produced depending on the magnitudes of the inclination theta of main rays. A light shielding means 11 having an aperture 10 of a middle stop is provided in the position proximate to the faces of the lens systems 2, 3 on the original 1 side, and the width of the aperture 10 gradually decreases from the end part to the central part and gradually increases from the central part to the other end part with respect to the moving directions of the lens systems 2, 3. With such constitution, image exposure is made on the drum 4 while substantially uniform quantity of light is being maintained in spite of a change in the angle theta.
JP11255080A 1980-08-15 1980-08-15 Variable magnification copying machine Pending JPS5737342A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP11255080A JPS5737342A (en) 1980-08-15 1980-08-15 Variable magnification copying machine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11255080A JPS5737342A (en) 1980-08-15 1980-08-15 Variable magnification copying machine

Publications (1)

Publication Number Publication Date
JPS5737342A true JPS5737342A (en) 1982-03-01

Family

ID=14589458

Family Applications (1)

Application Number Title Priority Date Filing Date
JP11255080A Pending JPS5737342A (en) 1980-08-15 1980-08-15 Variable magnification copying machine

Country Status (1)

Country Link
JP (1) JPS5737342A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59107339A (en) * 1982-12-13 1984-06-21 Toshiba Corp Image forming device
JPS59148042A (en) * 1983-02-15 1984-08-24 Ushio Inc Method and device for correcting illuminance of projection image
JPS6055325A (en) * 1983-09-06 1985-03-30 Ricoh Co Ltd Correcting device of uneven illuminance in variable magnification copying machine
JPS61109042A (en) * 1984-11-01 1986-05-27 Mita Ind Co Ltd Correcting mechanism for exposure quantity of copying machine

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59107339A (en) * 1982-12-13 1984-06-21 Toshiba Corp Image forming device
JPS59148042A (en) * 1983-02-15 1984-08-24 Ushio Inc Method and device for correcting illuminance of projection image
JPS6055325A (en) * 1983-09-06 1985-03-30 Ricoh Co Ltd Correcting device of uneven illuminance in variable magnification copying machine
JPS61109042A (en) * 1984-11-01 1986-05-27 Mita Ind Co Ltd Correcting mechanism for exposure quantity of copying machine

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