JPS5722265A - Exposure control device for copying machine - Google Patents

Exposure control device for copying machine

Info

Publication number
JPS5722265A
JPS5722265A JP9720180A JP9720180A JPS5722265A JP S5722265 A JPS5722265 A JP S5722265A JP 9720180 A JP9720180 A JP 9720180A JP 9720180 A JP9720180 A JP 9720180A JP S5722265 A JPS5722265 A JP S5722265A
Authority
JP
Japan
Prior art keywords
circuit
output voltage
voltage
limiting
output
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
JP9720180A
Other languages
Japanese (ja)
Other versions
JPS639207B2 (en
Inventor
Takeshi Nozaki
Original Assignee
Toshiba 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 Toshiba Corp filed Critical Toshiba Corp
Priority to JP55097201A priority Critical patent/JPS639207B2/ja
Publication of JPS5722265A publication Critical patent/JPS5722265A/en
Publication of JPS639207B2 publication Critical patent/JPS639207B2/ja
Expired legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G03PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03GELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
    • G03G15/00Apparatus for electrographic processes using a charge pattern
    • G03G15/04Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
    • G03G15/043Apparatus 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 means for controlling illumination or exposure

Abstract

PURPOSE:To automaticably obtain optimum exposure by limiting the output voltage of a photodetecting circuit by a limiting circuit in accordance with the output thereof, adding this limited voltage to the output voltage of a voltage forming circuit and applying the same to a comparator. CONSTITUTION:In the case of a dark original, the reflected light from the original is less and the quantity of light incident to a photodetecting circuit 40 is also less, hence the output voltage of a limiting circuit 38 is the value consisting of limiting the output voltage of the circuit 40 to a certain degree but is still low. Hence, if the value adding the output voltage of the circuit 38 to the output voltage of a waveform shaping circuit 34 is lower than the reference voltage from a reference voltage generating circuit 39, an error amplifier 37 amplifies the difference thereof and outputs the same to a trigger pulse generating circuit 41. Then, the circuit 41 controls a thyristor 32 so as to increase its conduction angle, thereby increasing the quantity of light of an exposure lamp 2.
JP55097201A 1980-07-16 1980-07-16 Expired JPS639207B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP55097201A JPS639207B2 (en) 1980-07-16 1980-07-16

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55097201A JPS639207B2 (en) 1980-07-16 1980-07-16

Publications (2)

Publication Number Publication Date
JPS5722265A true JPS5722265A (en) 1982-02-05
JPS639207B2 JPS639207B2 (en) 1988-02-26

Family

ID=14185986

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55097201A Expired JPS639207B2 (en) 1980-07-16 1980-07-16

Country Status (1)

Country Link
JP (1) JPS639207B2 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6031132A (en) * 1983-07-30 1985-02-16 Mita Ind Co Ltd Automatic exposing device
JPS6035752A (en) * 1983-08-06 1985-02-23 Canon Inc Image control device
JPS60216347A (en) * 1984-03-23 1985-10-29 Minolta Camera Co Ltd Automatic exposing device of electrophotographic copying machine
JPS61189579A (en) * 1985-02-19 1986-08-23 Sharp Corp Exposure adjusting device for copying machine
JPS61190328A (en) * 1985-02-20 1986-08-25 Fuji Xerox Co Ltd Exposing device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5182630A (en) * 1975-01-16 1976-07-20 Minolta Camera Kk

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5182630A (en) * 1975-01-16 1976-07-20 Minolta Camera Kk

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6031132A (en) * 1983-07-30 1985-02-16 Mita Ind Co Ltd Automatic exposing device
JPH0554094B2 (en) * 1983-07-30 1993-08-11 Mita Industrial Co Ltd
JPS6035752A (en) * 1983-08-06 1985-02-23 Canon Inc Image control device
JPS60216347A (en) * 1984-03-23 1985-10-29 Minolta Camera Co Ltd Automatic exposing device of electrophotographic copying machine
JPH071377B2 (en) * 1984-03-23 1995-01-11 ミノルタ株式会社 Automatic exposure device for electrophotographic copying machine
JPS61189579A (en) * 1985-02-19 1986-08-23 Sharp Corp Exposure adjusting device for copying machine
JPS61190328A (en) * 1985-02-20 1986-08-25 Fuji Xerox Co Ltd Exposing device

Also Published As

Publication number Publication date
JPS639207B2 (en) 1988-02-26

Similar Documents

Publication Publication Date Title
JPS53116852A (en) Automatic focus adjusting system
JPS5777935A (en) Safety device for photoconductive path
JPS6074878A (en) Store time corrector of photoelectric transducer
JPH01170591A (en) Workpiece processing device
EP0369806A3 (en) Focus adjuster
JPS5393021A (en) Aperture control device in variable power lens
JPS54133348A (en) Slit lighting device
JPS5913232A (en) Copying machine
JPS59135488A (en) Image forming device
JPH04134737A (en) Optical disk driving device and light quantity adjusting device
ES2085955T3 (en) Signal transition improvement device.
ES478576A1 (en) Digital pulse generator with end-stop detection and control
JPS61114647A (en) Picture reader
JPS6269577A (en) Output control device of pulse discharge type laser
JPS5894218A (en) Photocoupler
JPS5257825A (en) Automatic focus control device
JPS55119006A (en) Displacement measuring instrument
JPS5723914A (en) Recorder
JPS5219525A (en) Ttl light measure circuit for the camera
JPS5282264A (en) Range finder
JPS57161764A (en) Original lighting device of copying machine or the like
JPS5848477A (en) Condenser type solar electric generator
JPS5372667A (en) Analogue comparator
JPS52119927A (en) Device for automatic focus control
JPS599610A (en) Automatic focusing device