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US4611906A Expired / Lapsed US ⏱️ 0.0 years remaining

Electrophotographic copying apparatus

Assignee: Sanyo Electric Co Ltd
•
Filing: 1985-01-22
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Granted: 1986-09-16
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Expires: 2005-01-22
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Abstract

Abstract An electrophotographic copying apparatus of the present invention is capable of copying a reduced original and forms an electro-static latent image of the reduced original image on a uniformly electrified photosensitive member so that the electrostatic latent image is sensible-imaged as a toner image and the toner image is transferred onto copying paper. In such operation, this apparatus can change corresponding to reduction rate the irradiation area of a side erase lamp for erasing unnecessary charge at both axial edge portions of photosensitive member, thereby enabling complete removal of unnecessary electrified portions on the photosensitive member which appear inevitably when the reduced copying is carried out, and reliable prevention of attaching of unnecessary toner to the photosensitive member.

Inventors

  • 👤 Hiroshi Iwaki

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 03:10
CPC Classifications
G; G03; G03G; G03G15/00; G03G15/04; G03G15/045; G03G15/047; G03G2215/00; G03G2215/04; G03G2215/0429; G03G2215/0431; G03G2215/0434; G03G2215/0446; G03G2215/0448

Claims Analysis

Total Claims: 24
Claim 1
Independent Claim 209 words
An electrophotographic copying apparatus which uses means for exposure-scanning an original to form an electrostatic latent image of said original of equal or reduced size on an electrified photosensitive member follow-up-moving in the exposure-scanning direction, said electro-static latent image being developed with toner, so that an image of said toner is transferred to copying paper, characterized by providing; light sources disposed perpendicularly to the moving direction of said photosensitive member to irradiate the side edge portions thereof perpendicular to the moving direction of the same, thereby erasing unnecessary charge at said side edge portions, respectively; a shading member movable perpendicularly to the moving direction of said photosensitive member, thereby changing irradiation areas of said light sources; drive means for driving said shading member; reduction rate detection means for detecting a reduction rate; home position detection means for detecting the positioning of said shading member in a home position which is the basic position for controlling thereof; and control means responsive to output signals from both said reduction rate detection means and said home position detection means, for controlling said drive means for first positioning said shading member at the home position whenever the reduction rate is changed, and thereafter at a predetermined position corresponding to the new reduction rate.
Claim 2
Dependent Claim 209 words
An electrophotographic copying apparatus which uses means for exposure-scanning an original to form an electrostatic latent image of said original of equal or reduced size on an electrified photosensitive member follow-up-moving in the exposure-scanning direction, said electro-static latent image being developed with toner, so that an image of said toner is transferred to copying paper, characterized by providing; light sources disposed perpendicularly to the moving direction of said photosensitive member to irradiate the side edge portions thereof perpendicular to the moving direction of the same, thereby erasing unnecessary charge at said side edge portions, respectively; a shading member movable perpendicularly to the moving direction of said photosensitive member, thereby changing irradiation areas of said light sources; drive means for driving said shading member; reduction rate detection means for detecting a reduction rate; home position detection means for detecting the positioning of said shading member in a home position which is the basic position for controlling thereof; and control means responsive to output signals from both said reduction rate detection means and said home position detection means, for controlling said drive means for first positioning said shading member at the home position whenever the reduction rate is changed, and thereafter at a predetermined position corresponding to the new reduction rate.
Claim 3
Dependent Claim 44 words
An electrophotographic copying apparatus as set forth in claim 1, wherein said light sources are disposed opposite to said side edge portions perpendicular to the moving direction of said photosensitive member respectively and irradiate each of said side edge portions at said photosensitive member.
Claim 4
Dependent Claim 38 words
An electrophotographic copying apparatus as set forth in claim 2, wherein said shading member is a pair of members for changing the irradiation areas of said light sources at said side edge portions of said photosensitive member respectively.
Claim 5
Dependent Claim 36 words
An electrophotographic copying apparatus as set forth in claim 3, wherein said pair of shading members are driven by a common drive means to move in the opposite direction to each other by an equal distance.
Claim 6
Dependent Claim 28 words
An electrophotographic copying apparatus as set forth in claim 3, wherein said pair of shading members each have a rack engageable with a pinion provided between said racks.
Claim 7
Dependent Claim 18 words
An electrophotographic copying apparatus as set forth in claim 1, wherein said drive means is a stepping motor.
Claim 8
Dependent Claim 31 words
An electrophotographic copying apparatus as set forth in claim 1, wherein said shading member is a pair of members, and said detection means is provided at one of said photosensitive member.
Claim 9
Dependent Claim 17 words
An electrophotographic copying apparatus as set forth in claim 1, wherein said detection means is a photocoupler.
Claim 10
Dependent Claim 56 words
An electrophotographic copying apparatus as set forth in claim 8 wherein said photocoupler is movable in the moving direction of said shading member, biased by a spring in one moving direction of said shading member, and capable of regulating in position by a screw rotating for moving said photocoupler against a biasing force of said spring.
Claim 11
Dependent Claim 32 words
An electrophotographic copying apparatus as set forth in claim 1, wherein said shading members are supported to a support member integral with a support member for electrifying means for said photosensitive member.
Claim 12
Dependent Claim 166 words
An electrophotographic copying apparatus which uses means for exposure-scanning an original to form an electrostatic latent image corresponding to an original image onto an electrified photosensitive means, said electro-static latent image being developed with toner, thereby developing said toner image on copying paper, characterized by providing; light sources disposed perpendicularly to the moving direction of said photosensitive member and for irradiating side edge portions of said photosensitive member to erase unnecessary charge at said side edge portions, respectively; a pair of shading members movable by an equal distance in the direction opposite to each other and perpendicular to the moving direction of said photosensitive member, thereby changing the irradiation areas of said light sources at each of said side edge portions of said photosensitive member; detection means for detecting that one of the pair of shading members is placed in a home position which is the basic position from which the positioning of said shading member is controlled; and drive means for driving said shading members.
Claim 13
Dependent Claim 166 words
An electrophotographic copying apparatus which uses means for exposure-scanning an original to form an electrostatic latent image corresponding to an original image onto an electrified photosensitive means, said electro-static latent image being developed with toner, thereby developing said toner image on copying paper, characterized by providing; light sources disposed perpendicularly to the moving direction of said photosensitive member and for irradiating side edge portions of said photosensitive member to erase unnecessary charge at said side edge portions, respectively; a pair of shading members movable by an equal distance in the direction opposite to each other and perpendicular to the moving direction of said photosensitive member, thereby changing the irradiation areas of said light sources at each of said side edge portions of said photosensitive member; detection means for detecting that one of the pair of shading members is placed in a home position which is the basic position from which the positioning of said shading member is controlled; and drive means for driving said shading members.
Claim 14
Dependent Claim 28 words
An electrophotographic copying apparatus as set forth in claim 11, wherein said pair of shading members each have a rack engageable with a pinion interposed between said racks.
Claim 15
Dependent Claim 18 words
An electrophotographic copying apparatus as set forth in claim 11, wherein said drive means is a stepping motor.
Claim 16
Dependent Claim 17 words
An electrophotographic copying apparatus as set forth in claim 11, wherein said detecting means is a photocoupler.
Claim 17
Dependent Claim 57 words
An electrophotographic copying apparatus as set forth in claim 14, wherein said photocoupler is movable in the moving direction of said shading member, biased by a spring in one moving direction of said shading member, and capable of regulating in position by a screw which rotates to move said photocoupler against a biasing force of said spring.
Claim 18
Dependent Claim 33 words
An electrophotographic copying apparatus as set forth in claim 11, wherein said shading members are supported to a support member integral with a support member for said electrifying means for said photosensitive member.
Claim 19
Dependent Claim 189 words
An electrophotographic copying apparatus which uses means for exposure-scanning an original to form an electro-static latent image of said original of equal or reduced size on an electrified photosensitive member follow-up-moving in the exposure-scanning direction, said electro-static latent image being developed with toner, so that an image of said toner is transferred to copying paper, characterized by providing; light sources disposed perpendicularly to the moving direction of said photosensitive member to irradiate the side edge portions thereof perpendicular to the moving direction of the same, thereby erasing unnecessary charge at said side edge portions respectively; a shading member movable perpendicularly to the moving direction of said photosensitive member, thereby changing irradiation areas of said light sources; drive means for driving said shading member; detection means for detecting a reduction rate, said detection means consisting of a photocoupler; control means for controlling said drive means corresponding to the detection result of said detection means; and said shading member has a home position as the basic position for controlling thereof, and said shading member is provided with detection means for detecting that said shading member is put in the home position.
Claim 20
Dependent Claim 189 words
An electrophotographic copying apparatus which uses means for exposure-scanning an original to form an electro-static latent image of said original of equal or reduced size on an electrified photosensitive member follow-up-moving in the exposure-scanning direction, said electro-static latent image being developed with toner, so that an image of said toner is transferred to copying paper, characterized by providing; light sources disposed perpendicularly to the moving direction of said photosensitive member to irradiate the side edge portions thereof perpendicular to the moving direction of the same, thereby erasing unnecessary charge at said side edge portions respectively; a shading member movable perpendicularly to the moving direction of said photosensitive member, thereby changing irradiation areas of said light sources; drive means for driving said shading member; detection means for detecting a reduction rate, said detection means consisting of a photocoupler; control means for controlling said drive means corresponding to the detection result of said detection means; and said shading member has a home position as the basic position for controlling thereof, and said shading member is provided with detection means for detecting that said shading member is put in the home position.
Claim 21
Dependent Claim 56 words
An electrophotographic copying apparatus as set forth in claim 17, wherein said photocoupler is movable in the moving direction of said shading member, biased by a spring in one moving direction of said shading member, and capable of regulating in position by a screw rotating for moving said photocoupler against a biasing force of said spring.
Claim 22
Dependent Claim 167 words
An electrophotographic copying apparatus which uses means for exposure-scanning an original to form an electrostatic latent image corresponding to an original image onto an electrified photosensitive member, said electro-static latent image being developed with toner, thereby developing said toner image on copying paper, characterized by providing; light sources disposed perpendicularly to the moving direction of said photosensitive member and for irradiating side edge portions at said photosensitive member to erase unnecessary charge at said side edge portions respectively; a pair of shading members movable by an equal distance in the direction opposite to each other and perpendicular to the moving direction of said photosensitive member, thereby changing the irradiation areas of said light sources at said side edge portions of said photosensitive member; drive means for driving said shading members; and wherein said shading members have a home position as the basic position for controlling thereof, and said shading members are provided with a photocoupler for detecting that said shading members are put in the home position.
Claim 23
Dependent Claim 167 words
An electrophotographic copying apparatus which uses means for exposure-scanning an original to form an electrostatic latent image corresponding to an original image onto an electrified photosensitive member, said electro-static latent image being developed with toner, thereby developing said toner image on copying paper, characterized by providing; light sources disposed perpendicularly to the moving direction of said photosensitive member and for irradiating side edge portions at said photosensitive member to erase unnecessary charge at said side edge portions respectively; a pair of shading members movable by an equal distance in the direction opposite to each other and perpendicular to the moving direction of said photosensitive member, thereby changing the irradiation areas of said light sources at said side edge portions of said photosensitive member; drive means for driving said shading members; and wherein said shading members have a home position as the basic position for controlling thereof, and said shading members are provided with a photocoupler for detecting that said shading members are put in the home position.
Claim 24
Dependent Claim 58 words
An electrophotographic copying apparatus as set forth in claim 19, wherein said photocoupler is movable in the moving direction of said shading member, biased by a spring in one moving direction of said shading member, and capable of being regulated in position by a screw which rotates to move said photocoupler against a biasing force of said spring.

References Cited (Backward Citations)

US3724940A Cited
US3809472A Cited
US3792913A Cited
US3901593A Cited
US3967896A Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-09-15 1990-03-17 1990-09-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-09-15 1994-03-17 1994-09-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-09-15 1998-03-17 1998-09-16 $7700.00 Window Closed / Lapsed

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