Variable magnification image formation apparatus

Claim 2

A variable magnification image formation apparatus including: means for supporting an original; a photosensitive member; a zoom lens assembly disposed in an optical path between said means for supporting an original and said photosensitive member for forming an image of the original on said photosensitive member, said zoom lens assembly having a rotational member rotatable about the optical axis of the lens to change the focal length of the zoom lens, and the length of said optical path being constant irrespective of selected magnification; zoom lens assembly moving means for moving said zoom lens assembly along a predetermined path to change the magnification of the image of the original; a wire member wound onto said rotational member; and wire member moving means for moving said wire member at the movement speed of said zoom lens assembly multiplied by a predetermined constant different from 1 in synchronism with the operation of said zoom lens assembly moving means to rotate said rotational member.

Claim 3

An apparatus according to claim 1, wherein said zoom lens assembly moving means and said wire member moving means have a common drive source.

Claim 4

An apparatus according to claim 2, wherein said zoom lens assembly moving means has a wire member mechanically connected to said zoom lens assembly, and a first drive pulley with which said wire member mechanically connected to said zoom lens assembly is engaged and which is rotatively driven by said drive source, and said wire member moving means has a second drive pulley with which said wire member wound on to said rotational member is engaged and which is rotatively driven by said drive source, said second drive pulley differing in diameter from said first drive pulley.

Claim 5

A variable magnification image formation apparatus including: means for supporting an original; a photosensitive member; a zoom lens assembly disposed in an optical path between said original supporting means and said photosensitive member for forming an image of the original on said photosensitive member, said zoom lens assembly having at least first and second lenses disposed along the optical axis of the lens, and a rotational member rotatable about the optical axis of the lens to move said second lens relative to said first lens along the optical axis of the lens, and the length of said optical path being constant irrespective of selected magnification; a movable carriage supporting said zoom lens assembly thereon; carriage moving means for moving said movable carriage along a predetermined path having at least the direction of the optical axis of the lens as a direction component to change the magnification of the image of the original; a wire member wound on to said rotational member; and wire member moving means for moving said wire member in response to the operation of said carriage moving means to rotate said rotational member about the optical axis of the lens, said wire member moving means moving said wire member at a speed of C×V, where C is a predetermined constant and V is the speed of the carriage.

Claim 6

A variable magnification image formation apparatus including: means for supporting an original; a photosensitive member; a zoom lens assembly disposed in an optical path between said original supporting means and said photosensitive member for forming an image of the original on said photosensitive member, said zoom lens assembly having at least first and second lenses disposed along the optical axis of the lens, and a rotational member rotatable about the optical axis of the lens to move said second lens relative to said first lens along the optical axis of the lens, and the length of said optical path being constant irrespective of selected magnification; a movable carriage supporting said zoom lens assembly thereon; carriage moving means for moving said movable carriage along a predetermined path having at least the direction of the optical axis of the lens as a direction component to change the magnification of the image of the original; a wire member wound on to said rotational member; and wire member moving means for moving said wire member in response to the operation of said carriage moving means to rotate said rotational member about the optical axis of the lens, said wire member moving means moving said wire member at a speed of C×V, where C is a predetermined constant and V is the speed of the carriage.

Claim 7

An apparatus according to claim 4, wherein said wire member is engaged with said rotational member so that during movement of the carriage, it is not moved relative to the rotational member in the direction of the optical axis of the lens.

Claim 8

An apparatus according to claim 5, wherein said wire member moving means has wire direction changing means disposed on said carriage for changing the direction of said wire member at positions before and behind the portion engaged with said rotational member, and wire member supporting means for supporting said wire member in parallelism to the movement path of the carriage between itself and said direction changing means.

Claim 9

An apparatus according to claim 6, wherein said carriage moving means has a wire member engaged with the carriage and extended in parallelism to the movement path of the carriage before and behind the portion engaged with the carriage, and a first drive pulley for driving said wire member engaged with the carriage said wire member moving means is provided with a second drive pulley for driving the wire member engaged with said rotational member, and said first and second drive pulleys are driven by the same drive source.

Claim 11

A variable magnification image formation apparatus including: means for supporting an original; a photosensitive member; an optical path between said original supporting means and said photosensitive member, said optical path having a constant length irrespective of selected magnification; a zoom lens assembly disposed in said optical path for forming an image of the original on said photosensitive member at a selected magnification, said zoom lens assembly having a first lens barrel portion having a cam, and a second lens barrel portion engaged with said cam and rotatable relative to said first lens barrel portion about the optical axis of the lens and movable relative to said first lens barrel portion in the direction of the optical axis of the lens, said cam having a shape for moving said second lens barrel portion relative to said first lens barrel portion in the direction of the optical axis of the lens to change the zoom lens focal length when said second lens barrel portion is rotated relative to said first lens barrel portion about the optical axis of the lens; a movable carriage supporting said zoom lens assembly thereon; carriage moving means for moving said carriage to a position corresponding to the selected magnification along a predetermined path having at least the direction of the optical axis of the lens as a direction component; a wire member wound on to said zoom lens assembly for rotating said first and second lens barrel portions relative to each other about the optical axis of the lens; and wire member moving means for moving said wire member by an amount corresponding to the selected magnification in synchronism with the movement of said carriage, said wire member moving means moving said wire member at the speed of said carriage multiplied by a predetermined constant.

Claim 12

A variable magnification image formation apparatus including: means for supporting an original; a photosensitive member; an optical path between said original supporting means and said photosensitive member, said optical path having a constant length irrespective of selected magnification; a zoom lens assembly disposed in said optical path for forming an image of the original on said photosensitive member at a selected magnification, said zoom lens assembly having a first lens barrel portion having a cam, and a second lens barrel portion engaged with said cam and rotatable relative to said first lens barrel portion about the optical axis of the lens and movable relative to said first lens barrel portion in the direction of the optical axis of the lens, said cam having a shape for moving said second lens barrel portion relative to said first lens barrel portion in the direction of the optical axis of the lens to change the zoom lens focal length when said second lens barrel portion is rotated relative to said first lens barrel portion about the optical axis of the lens; a movable carriage supporting said zoom lens assembly thereon; carriage moving means for moving said carriage to a position corresponding to the selected magnification along a predetermined path having at least the direction of the optical axis of the lens as a direction component; a wire member wound on to said zoom lens assembly for rotating said first and second lens barrel portions relative to each other about the optical axis of the lens; and wire member moving means for moving said wire member by an amount corresponding to the selected magnification in synchronism with the movement of said carriage, said wire member moving means moving said wire member at the speed of said carriage multiplied by a predetermined constant.

Claim 13

An apparatus according to claim 9, wherein said first lens barrel portion is mounted on said carriage so that it does not move relative to said carriage in the direction of the optical axis of the lens.

Claim 14

An apparatus according to claim 10, wherein said zoom lens assembly has a third lens barrel portion rotatable about the optical axis of the lens at a predetermined position on said carriage and operatively connected to said second lens barrel portion, and said wire member is wound on to said third lens barrel portion so that during movement of said carriage, it does not move relative to said third lens barrel portion in the direction of the optical axis of the lens.

Claim 15

An apparatus according to claim 9, wherein said second lens barrel portion is mounted on said carriage so that it does not move relative to said carriage in the direction of the optical axis of the lens.

Claim 16

An apparatus according to claim 12, wherein said zoom lens assembly has a third lens barrel portion rotatable about the optical axis of the lens at a predetermined position on said carriage and operatively connected to said first lens barrel portion, and said wire member is wound onto said third lens barrel portion so that during movement of said carriage, it does not move relative to said third lens barrel portion in the direction of the optical axis of the lens.

Claim 18

An apparatus according to claim 14, wherein said constant differs from 1.

Claim 19

An apparatus according to claim 15, wherein said wire member moving means has wire direction changing means disposed on said carriage for changing the direction of said wire member at positions before and behind the portion engaged with said zoom lens assembly, and wire member supporting means for supporting said wire member in parallelism to the movement path of the carriage between it and said direction changing means.

Claim 20

An apparatus according to claim 16, wherein said carriage moving means has a wire member engaged with the carriage and extended in parallelism to the movement path of the carriage before and behind the portion engaged with the carriage, and a first drive pulley for driving said wire member, said wire member engaged with the carriage moving means is provided with a second drive pulley for driving the wire member engaged with said zoom lens assembly, and said first and second drive pulleys are driven by the same drive source.

Claim 21

A variable magnification image formation apparatus in which at least first and second image formation magnifications can be selected, including: means for supporting an original; a photosensitive member; an optical path between said original supporting means and said photosensitive member, said optical path having a constant length irrespective of selected magnification; a zoom lens assembly disposed in said optical path for forming an image of the original on said photosensitive member at a selected magnification, said zoom lens assembly having a first lens barrel portion having a cam for changing the focal length correspondingly to the selected magnification, a second lens barrel portion engaged with said cam and rotatable relative to said first lens barrel portion about the optical axis of the lens and movable relative to said first lens barrel portion in the direction of the optical axis of the lens, a first area of said cam corresponding to a first magnification and a second area of said cam corresponding to a second magnification being perpendicular to the optical axis of the lens, a third area connecting said first area and said second area being inclined relative to the optical axis of the lens; a movable carriage supporting said zoom lens assembly thereon; carriage moving means for moving said carriage to a position corresponding to the selected magnification along a predetermined path having at least the direction of the optical axis of the lens as a direction component; a wire member wound on to said zoom lens assembly for rotating said first and second lens barrel portions relative to each other about the optical axis of the lens; and wire member moving means for moving said wire member by an amount corresponding to the selected magnification in synchronism with the movement of said carriage, said wire member moving means moving said wire member at the speed of said carriage multiplied by a predetermined constant.

Claim 22

A variable magnification image formation apparatus in which at least first and second image formation magnifications can be selected, including: means for supporting an original; a photosensitive member; an optical path between said original supporting means and said photosensitive member, said optical path having a constant length irrespective of selected magnification; a zoom lens assembly disposed in said optical path for forming an image of the original on said photosensitive member at a selected magnification, said zoom lens assembly having a first lens barrel portion having a cam for changing the focal length correspondingly to the selected magnification, a second lens barrel portion engaged with said cam and rotatable relative to said first lens barrel portion about the optical axis of the lens and movable relative to said first lens barrel portion in the direction of the optical axis of the lens, a first area of said cam corresponding to a first magnification and a second area of said cam corresponding to a second magnification being perpendicular to the optical axis of the lens, a third area connecting said first area and said second area being inclined relative to the optical axis of the lens; a movable carriage supporting said zoom lens assembly thereon; carriage moving means for moving said carriage to a position corresponding to the selected magnification along a predetermined path having at least the direction of the optical axis of the lens as a direction component; a wire member wound on to said zoom lens assembly for rotating said first and second lens barrel portions relative to each other about the optical axis of the lens; and wire member moving means for moving said wire member by an amount corresponding to the selected magnification in synchronism with the movement of said carriage, said wire member moving means moving said wire member at the speed of said carriage multiplied by a predetermined constant.

Claim 23

An apparatus according to claim 18, wherein said first lens barrel is mounted on said carriage so that it does not move relative to said carriage in the direction of the optical axis of the lens.

Claim 24

An apparatus according to claim 19, wherein said zoom lens assembly has a third lens barrel portion rotatable about the optical axis of the lens at a predetermined position on said carriage and operatively connected to said second lens barrel portion, and said wire member is wound onto said third lens barrel portion so that during movement of said carriage, it does not move relative to said third lens barrel portion in the direction of the optical axis of the lens.

Claim 25

An apparatus according to claim 18, wherein said second lens barrel portion is mounted on said carriage so that it does not move relative to said carriage in the direction of the optical axis of the lens.

Claim 26

An apparatus according to claim 21, wherein said zoom lens assembly has a third lens barrel portion rotatable about the optical axis of the lens at a predetermined position on said carriage and operatively connected to said first lens barrel portion, and said wire member is wound onto said third lens barrel portion so that during movement of said carriage, it does not move relative to said third lens barrel portion in the direction of the optical axis of the lens.

Claim 28

An apparatus according to claim 23, wherein said constant differs from 1.

Claim 29

An apparatus according to claim 24, wherein said wire member moving means has wire direction changing means disposed on said carriage for changing the direction of said wire member at positions before and behind the portion engaged with said zoom lens assembly, and wire member supporting means for supporting said wire member in parallelism to the movement path of the carriage between itself and said direction changing means.

Claim 30

An apparatus according to claim 25, wherein said carriage moving means has a wire member engaged with the carriage and extended in parallelism to the movement path of the carriage before and behind the portion engaged with the carriage, and a first drive pulley for driving said wire member engaged with the carriage, said wire member moving means is provided with a second drive pulley for driving the wire member engaged with said zoom lens assembly, and said first and second drive pulleys are driven by the same drive source.