JPH0455294B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to an exposure scanning device that can be used in electronic copying machines, facsimile machines, document files, and the like.

(b) Prior Art Conventional exposure scanning devices use lenses whose conjugate length changes by changing the magnification, as described in Japanese Patent Publication No. 58-20428 and Japanese Utility Model Publication No. 49-3297. Therefore, it was necessary to move the position of the reflecting mirror parallel to the optical axis each time a magnification change operation was performed. Therefore, the wires for driving the reflecting mirror are wired in a complicated manner, making the mechanism complicated, making it impossible to improve reliability and reduce costs.

In addition, as an exposure scanning device that can adjust the chain and wire that drives the reflecting mirror,
The one described in Publication No. 35717 is known. However, this exposure scanning device also has a complicated mechanism.
I had the same problem as above.

(C) Purpose of the Invention The present invention has been made in view of the drawbacks of the prior art described above, and it is possible to solve the problem by using a zoom lens in which the conjugate length does not change even when changing the magnification. By configuring the structure so that the fixing position of the reflector with respect to the wire that drives the reflector and the belt can be easily adjusted, the method of hanging the wire that drives the reflector is simplified, improving reliability and reducing costs. It is intended to be

(D) Structure of the Invention The present invention includes a base body, a holding rod extending in the exposure scanning direction of the original document, and a first movable mirror that reflects the original image.
a first holding stand slidably attached to the holding rod for holding the first movable mirror; and a second movable mirror for re-reflecting the document image reflected by the first movable mirror. , for holding this second movable mirror,
a second holding stand slidably attached to the holding rod or another holding rod parallel to this holding rod; at least two pulleys provided on the second holding stand; and a second movable mirror. a fixed mirror that reflects the reflected original image toward a light-receiving surface; this fixed mirror and the table 2;
a variable magnification lens whose conjugate length is always constant and which is provided between the movable mirror and which has both ends adjustably fixed to the base body via a first fixture, and which is provided on a first holding base; The second fixture is also fixed to allow greater adjustment than the adjustment by the both ends, and the first belt-shaped body is stretched around a pulley provided on the second holding base. , a motor for driving the first holding stand and the second holding stand;
A second band-shaped body is provided that is stretched between the rotation shaft of the motor and an idler that is rotatably attached to the base, and the second band-shaped body is connected to the second fixture. It is characterized in that it is adjustable and fixed together with the first band-shaped body, and the driving force of the motor is transmitted to the first holder and the second holder via this second fixture.

(e) Embodiment The drawings all show an example in which the present invention is implemented in an electronic copying machine, with FIG. 1 being a schematic configuration diagram, FIG. 2 being a perspective view, and FIG. 3 being a side view.

In FIG. 1, reference numeral 1 denotes a document table made of transparent glass, on which a document 2 is placed. Also,
Reference numeral 3 denotes a photosensitive drum as a light-receiving surface on which an original image is formed.

Reference numeral 4 designates a guide bar serving as a holding rod extending in the exposure scanning direction, and reference numeral 5 designates a guide rail extending parallel to this guide bar 4. A first holding table 6 is slidably held on the guide bar 4, and a first movable mirror 7 that reflects the original image is attached to the first holding table 6.
One end is fixed.

A wheel 8 is rotatably mounted on the other end of the first movable mirror 7, and this other end is supported by the guide rail 5 via the wheel 8. Although not shown, a rod-shaped light source (for example, a fluorescent lamp) is attached to the side of the first movable mirror 7 and extends parallel to the first movable mirror 7, and this light source illuminates the original during image formation. is exposed.

A second holder 9 is slidably attached to the guide bar 4, and has a box shape with an open top extending in the direction in which the guide bar 9 extends.
A concave cutout 10 is formed in a portion that interferes with the holding base 6. At one end of this second holding stand 9,
One end of a second movable mirror 11 extending in a direction perpendicular to the extending direction of the second support base 9 is fixedly provided, and the other end of the second movable mirror 11 is provided with the other end of the first movable mirror 7. A wheel 12 similar to the wheel 8 mounted at the end is rotatably mounted and supported by the guide rail 5. Note that the second holding stand 9 may be attached to another guide bar that is provided parallel to the guide bar 4.

The second movable mirror 11 is composed of two reflecting mirrors 11a and 11b orthogonal to each other, and the first movable mirror 7
It receives the original image reflected by the zoom lens 13 and further reflects it toward the zoom lens 13. Note that this zoom lens 13 is a lens whose conjugate length is always constant even when the magnification is changed.

The second movable mirror 1 holds the zoom lens 13 in between.
On the opposite side from 1, a fixed mirror 14 is fixed to the base (chassis) of the copying machine, and this fixed mirror 14
The original image that has been reflected by the second movable mirror 11 and transmitted through the zoom lens 13 is reflected again toward the surface of the photosensitive drum 3.

Near both ends of the vertical wall of the second holding table 9,
One pulley 15, 16 is rotatably mounted on each pulley, and a wire 17 for driving both the first holding table 6 and the second holding table 9 is stretched therebetween. Further, the base end of a wire holding stand 18 as a fixing fitting extending in the horizontal direction is fixed to the first holding stand 6, and a wire fixing plate 19 is attached to the upper part of this wire holding stand 18, and the wire 17 is attached to the first holding stand 6. is adjustable and held between the wire holding base 18 and the wire fixing plate 19. One end of the wire 17 is engaged with one of the upright tongue pieces 20a of the wire fixture 20 fixed to the base, and the other end is engaged with the other upright tongue piece 20b of the wire fixture 20 via the tension spring 21. is engaged. Note that the wire fixture 20 has a long hole 20 extending in a direction parallel to the direction in which the guide bar 4 extends.
c and 20d are provided, and by shifting the fixed position of the wire fixing plate 20, the position of the first movable mirror 7 can be finely adjusted. That is, the third
In the figure, when the wire fixture 20 is moved by L, the second movable mirror 11 is moved by L/2.

Reference numeral 22 denotes a timing belt for driving both the holding stands 6 and 9, which includes a timing pulley 24 fixed to the rotating shaft of the scan motor 23, and a timing pulley 25 as an idler rotatably attached to the base. A part of the upper side thereof is held adjustable together with the wire 17 by the wire holding stand 18 and the wire fixing plate 19.

When the scan motor 23 rotates clockwise, the first holding table 6 moves to the right at a speed V. At this time, if the exposure lamp is lit, the original is exposed and scanned. be done. When this first holding stand 6 moves to the right at a speed V, one of the pulleys 16 attached to the second holding stand 9 acts as a movable pulley, and the second holding stand 9 moves to the right side of the first holding stand. Move in the same direction as 6 (to the right) at a speed of 1/2V. Therefore, the first
When the movable mirror 7 exposes and scans the original, the distance from the original surface to the zoom lens 13 is always constant.

Note that the number of the second movable mirrors 11 is not necessarily two, and may be one.

(F) Effects of the Invention In the present invention, since a variable power lens whose conjugate length is always constant is used, there is no need to move the position of the reflecting mirror parallel to the optical axis each time a variable power operation is performed. Therefore, it is possible to simplify the way in which a belt-shaped body such as a wire or belt for driving the reflecting mirror is attached, and it is possible to realize a highly reliable and inexpensive exposure scanning device.

The first belt-shaped body and the second belt-shaped body transmit the driving force of the motor to the first holding body and the second holding body.
Both ends of the band-like body are fixed in a finely adjustable manner, and further, the second band-like body is attached to the second fixture,
Since the movable mirrors are fixed together with the belt-shaped body to allow greater adjustment than the adjustment by the two ends, accurate positional adjustment of each movable mirror can be performed extremely easily, and the distance between the document surface and the variable magnification lens can be adjusted very easily. It can be adjusted constant. As a result, even if a bright lens with a shallow depth of focus is used as a variable magnification lens, the original image can be sharply combined with the light receiving surface, and a high quality image can be obtained.

[Brief explanation of the drawing]

Each of the drawings shows one embodiment of the present invention.
The figure is a schematic configuration diagram, the second figure is a perspective view, and the third figure is a side view. 1... Original table, 2... Original, 3... Photosensitive drum (light receiving surface), 4... Guide bar (holding rod), 6...
...First holding stand, 7... First movable mirror, 9... Second holding stand, 11... Second movable mirror, 13... Zoom lens (variable magnification lens), 14... Fixed mirror, 15, 16
... Pulley, 17 ... Wire, 18 ... Wire holding stand (fixing bracket), 19 ... Wire fixing plate, 20
...Wire fixture, 22...Timing belt,
23...Scan motor.

Claims (1)

[Claims] 1 a base, a holding rod extending in the exposure scanning direction of the original, a first movable mirror that reflects the original image, and this first
a first holding stand slidably attached to the holding rod for holding the movable mirror; a second movable mirror for re-reflecting the document image reflected by the first movable mirror; 2. A second holding stand slidably attached to the holding rod or another holding rod parallel to this holding rod for holding the movable mirror; and at least two holding stands provided on this second holding stand. A pulley, a fixed mirror that reflects the original image reflected by the second movable mirror toward the light-receiving surface, and a conjugate length of which the conjugate length always changes are provided between the fixed mirror and the movable mirror of the table 2. A double lens, both ends of which are adjustable, are fixed to the base body via a first fixture, and also fixed to a second fixture provided on the first holding base. a first belt-shaped body fixed to allow a large adjustment by the second holding table, and further wrapped around a pulley provided on the second holding table;
The second belt-shaped body is provided with a motor for driving the holding base, and a second belt-like body stretched between the rotation shaft of the motor and an idler rotatably attached to the base body. The strip is adjustably fixed to the second fixture together with the first strip, and the driving force of the motor is applied to the first holder and the second holder via the second fixture. An exposure scanning device characterized in that: