JPS55142368A - Variable magnification copying machine - Google Patents

Variable magnification copying machine

Info

Publication number
JPS55142368A
JPS55142368A JP5112879A JP5112879A JPS55142368A JP S55142368 A JPS55142368 A JP S55142368A JP 5112879 A JP5112879 A JP 5112879A JP 5112879 A JP5112879 A JP 5112879A JP S55142368 A JPS55142368 A JP S55142368A
Authority
JP
Japan
Prior art keywords
speed
copy
changed
potential
drum
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
JP5112879A
Other languages
Japanese (ja)
Other versions
JPS6131458B2 (en
Inventor
Shigehiro Komori
Hiroshi Ogawa
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 JP5112879A priority Critical patent/JPS55142368A/en
Priority to US06/141,922 priority patent/US4411514A/en
Priority to DE19803015820 priority patent/DE3015820A1/en
Publication of JPS55142368A publication Critical patent/JPS55142368A/en
Publication of JPS6131458B2 publication Critical patent/JPS6131458B2/ja
Granted legal-status Critical Current

Links

Landscapes

  • Variable Magnification In Projection-Type Copying Machines (AREA)
  • Control Or Security For Electrophotography (AREA)
  • Exposure Or Original Feeding In Electrophotography (AREA)

Abstract

PURPOSE:To obtain uniform copy images of scarce blur without increasing power consumption, by altering the magnification by selectively varying the moving speed of photoreceptor and intensity of electric field between the photoreceptor and charging and destaticizing means. CONSTITUTION:When changing from equal magnification copy to reduced copy, an inmirror lens 6 and a fixed mirror 7 are switched to an inmirror lens 6' and a fixed mirror 7', and the peripheral speed of a photosensitive drum 8 is changed to low speed. At the same time, the speed of rollers 20, 21 to convey a copying paper 22 is changed so that the conveying speed may coincide with the peripheral speed of the drum 8. Further the surface potential of the photosensitive drum 8 is measured by a surface potential sensor 28 during previous rotation of the drum, and the target potential constant preset in a control circuit and the measured result are compared. The correcting current is combined with the reference current to keep the surface potential within a certain specification. Hence, the voltage applied to corona dischargers 10, 12 is changed to be lower than in equal magnification copying operation. Thus, the bright part potential and dark part potential are both kept within the specified values, so that an excellent copy image may be always obtained.
JP5112879A 1979-04-24 1979-04-24 Variable magnification copying machine Granted JPS55142368A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
JP5112879A JPS55142368A (en) 1979-04-24 1979-04-24 Variable magnification copying machine
US06/141,922 US4411514A (en) 1979-04-24 1980-04-21 Variable magnification electrophotographic copying apparatus
DE19803015820 DE3015820A1 (en) 1979-04-24 1980-04-24 Variable magnification photocopier with constant scanning speed - has variable speed photo-sensitive layer and corrected corona charging rate

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5112879A JPS55142368A (en) 1979-04-24 1979-04-24 Variable magnification copying machine

Publications (2)

Publication Number Publication Date
JPS55142368A true JPS55142368A (en) 1980-11-06
JPS6131458B2 JPS6131458B2 (en) 1986-07-21

Family

ID=12878160

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5112879A Granted JPS55142368A (en) 1979-04-24 1979-04-24 Variable magnification copying machine

Country Status (1)

Country Link
JP (1) JPS55142368A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5792342A (en) * 1980-11-28 1982-06-08 Canon Inc Picture reproducing method
JPS57104157A (en) * 1980-12-19 1982-06-29 Canon Inc Variable magnitude copying machine
JPS59136728A (en) * 1983-01-26 1984-08-06 Canon Inc Image forming device
JPS59159153A (en) * 1983-02-28 1984-09-08 Canon Inc Reproducing and outputting device of image
JPS6143773A (en) * 1984-08-07 1986-03-03 Canon Inc Image forming device
US6853816B2 (en) * 2002-04-26 2005-02-08 Kabushiki Kaisha Toshiba Image forming apparatus and method for adjusting magnification of image information

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS49114428A (en) * 1973-02-28 1974-10-31
JPS50125739A (en) * 1974-03-20 1975-10-03
JPS5242125A (en) * 1975-09-30 1977-04-01 Ricoh Co Ltd Transfer process for toner image and device therefor
JPS5365736A (en) * 1976-11-25 1978-06-12 Ricoh Co Ltd Variable magnification copier
JPS549631A (en) * 1977-06-22 1979-01-24 Fujitsu Ltd Automatic control system for charging amount
JPS5446563A (en) * 1977-09-20 1979-04-12 Minolta Camera Co Ltd Copying apparatus for zerography

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS49114428A (en) * 1973-02-28 1974-10-31
JPS50125739A (en) * 1974-03-20 1975-10-03
JPS5242125A (en) * 1975-09-30 1977-04-01 Ricoh Co Ltd Transfer process for toner image and device therefor
JPS5365736A (en) * 1976-11-25 1978-06-12 Ricoh Co Ltd Variable magnification copier
JPS549631A (en) * 1977-06-22 1979-01-24 Fujitsu Ltd Automatic control system for charging amount
JPS5446563A (en) * 1977-09-20 1979-04-12 Minolta Camera Co Ltd Copying apparatus for zerography

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5792342A (en) * 1980-11-28 1982-06-08 Canon Inc Picture reproducing method
JPS57104157A (en) * 1980-12-19 1982-06-29 Canon Inc Variable magnitude copying machine
JPS59136728A (en) * 1983-01-26 1984-08-06 Canon Inc Image forming device
JPH0541993B2 (en) * 1983-01-26 1993-06-25 Canon Kk
JPS59159153A (en) * 1983-02-28 1984-09-08 Canon Inc Reproducing and outputting device of image
JPS6143773A (en) * 1984-08-07 1986-03-03 Canon Inc Image forming device
US6853816B2 (en) * 2002-04-26 2005-02-08 Kabushiki Kaisha Toshiba Image forming apparatus and method for adjusting magnification of image information

Also Published As

Publication number Publication date
JPS6131458B2 (en) 1986-07-21

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