Back to results
US 4,284,346 AGranted
Electrophotographic copying machine
AssigneeMinolta Camera Kabushiki Kaisha
InventorsHiroshi Ikeda, Seiichi Sakurai
Life of this patent
Estimating the term…
Abstract
An electrophotographic copying machine comprises a transparent support for the support of an original to be copied, a photo-receptor, an optical projecting system for projecting an image of the original onto the photo-receptor and an exposure adjustment for controlling a pattern of distribution on the photo-receptor of rays of light carrying the image of the original. The optical projecting system includes a projecting lens assembly supported for movement between at least first and second positions wherein the image of the original can be reproduced on a copying paper in different magnifications. The exposure adjustment is positioned between the transparent support and the optical projecting system and is comprised of a fixedly supported light shielding member.
Claims22
An electrophotographic copying machine of a type selectively operable in a plurality of magnifications, which comprises, in combination:
- an original support for supporting thereon an original to be copied;
- a photo-receptor movable past an exposure station;
- an optical projecting means including a movably supported projecting lens and positioned between the original support and the photo-receptor for forming an optical path for projecting an image of the original onto the photo-receptor at the exposure station;
- means connected to said projecting lens for varying the magnification of the image of the original formed by the optical projecting means between first and second magnifications by moving said projecting lens for varying said optical path, the second magnification being smaller than said first magnification;
- and
- an exposure adjustment means including a light shielding member fixedly positioned along said optical path in a non-interfering position relative to said optical path when said optical projecting means is projecting the image at said first magnification and in a position relative to said optical path for blocking part of the image light directed toward said projecting means when said projecting means is projecting the image at said second magnification for controlling the pattern of distribution of light carrying the image of the original on said photo-receptor when projecting at said second magnification.
3 more elements
An electrophotographic copying machine of a type selectively operable in a plurality of magnifications, which comprises, in combination:
- an original support for supporting thereon an original to be copied;
- a photo-receptor movable past an exposure station;
- an optical projecting means positioned between the original support and the photo-receptor for forming an optical path for projecting an image of the original onto the photo-receptor at the exposure station, said optical projecting means including a movably supported projecting lens means;
- means connected to said projecting lens means for moving the projecting lens means for varying the magnification of the image of the original relative to the original among a first, second and third magnifications for varying said optical path, said first magnification being larger than said second magnification and said second magnification being larger than said third magnification;
- and
- a fixedly supported light shielding member fixedly positioned along said optical path in a non-interfering position relative to said optical path when said optical projecting lens means is in a position for projecting the image at said first magnification and in a position relative to said optical path for blocking part of the image light directed toward said projecting means when said projecting lens means is in a position for projecting the image at said second and third magnifications for controlling the pattern of distribution of light carrying the image of the original on said photo receptor when projecting at said second or third magnifications respectively.
3 more elements
An electrophotographic copying machine of a type selectively operable in a plurality of magnifications, which comprises, in combination:
- an original support for supporting thereon an original to be copied;
- a photo-receptor movable past an exposure station;
- an optical projecting means positioned between the original support and the photo-receptor for forming an optical path for projecting an image of the original onto the photo-receptor at the exposure station, said optical projecting means including a projecting lens means which is movably supported;
- means connected to said projecting lens means for moving the projecting lens means for varying the magnification of the image of the original relative to the original among a first, second, third and fourth magnifications for varying said optical path, said magnifications being successively less in the order of said first, second, third and fourth magnifications;
- and
- a fixedly supported light shielding member fixedly positioned along said optical path in a non-interfering position relative to said optical path when said optical projecting lens means is in a position for projecting the image at said first magnification and in a position relative to said optical path for blocking part of the image light directed toward said projecting means when said projecting lens means is in a position for projecting the image at one of said second, third and fourth magnifications for controlling the pattern of distribution of light carrying the image of the original on said photo-receptor when projecting at said second, third and fourth magnifications respectively.
3 more elements
An electrophotographic copying machine of a slit exposure type selectively operable in a plurality of magnifications, which comprises, in combination:
- an original support for supporting thereon an original to be copied;
- a photo-receptor movable past an exposure station;
- an optical projecting means including an exposure slit defining means and a movably supported projecting lens means and positioned between the original support and the photo-receptor for forming an optical path for projecting an image on the original in a line scan fashion through the exposure slit and the projecting lens means onto the photo-receptor at the exposure station;
- means connected to said projecting lens means for moving said projecting lens means for varying the magnification of the image of the original formed by the optical projecting means between at least first and second magnifications, the second magnification being smaller than said first magnification;
- and
- an exposure adjustment means including a light sliding member fixedly positioned along said optical path in a non-interfering position relative to said optical path when said projecting lens means is projecting the image at said first magnification and in a position relative to said optical path for blocking part of the image light in a direction lengthwise of the exposure slit when said projecting means is projecting the image at said second magnification for controlling the pattern of distribution of light carrying the image of the original on said photo-receptor.
3 more elements
An electrophotographic copying machine of a mirror scan type selectively operable in a plurality of magnification, which comprises, in combination:
- an original support for supporting thereon an original to be copied;
- a photo-receptor movable past an exposure station;
- an optical projecting means positioned between the original support and the photo-receptor for forming an optical path for projecting an image of the original onto the photo-receptor at the exposure station, said optical projecting means including a movably supported projecting lens means, an exposure slit defining means and a scanning mirror assembly;
- means connected to said projecting lens means for moving the projecting lens means for varying the magnification of the image of the original projected onto the photo-receptor by said optical projecting means between a first magnification and a second magnification by varying said optical path, said second magnification being smaller than said first magnification;
- and p1 a light shielding member fixedly positioned along said optical path in a non-interfering position relative to said optical path when said optical projecting means is projecting the image at said first magnification and in a position relative to said optical path for blocking part of the image light in a direction lengthwise of the exposure slit when said projecting means is projecting the image of said second magnification for controlling the pattern of distribution of light carrying the original image.
2 more elements
Dependencies are inferred from the claim text.