JPH06347903A - Variable power copying machine - Google Patents

Abstract

PURPOSE:To prevent an image blurring from being generated at the leading edge part of an image without making a machine large by moving a lens arranged in the optical path of reflected light from an original to an image forming body side and moving it in parallel with an image scanning direction at the time of reduction copying. CONSTITUTION:Original exposing positions P1 and P3 are expressed as fixed, but the original exposing positions (P1 and P3) are moved in a counter image scanning direction (counter to a direction shown by an arrow D) by moving an optical system in the copying machine where the scanning of an original is performed by moving the optical system. In the original platen moving type copying machine, the original exposing positions (P1 and P3) are fixed and an original platen is moved in the direction shown by the arrow D (image scanning direction). The lens L is moved in parallel in the image scanning direction in comparison with the conventional position shown by a dotted chain line. Then, the original exposing position guided to an exposing point P2 is moved to the P3 and moved in the image scanning direction. Therefore, the start of exposing the original is delayed by a 'distance between 'P3-P1', that means, the run-up distance of the optical system becomes longer by that distance, thereby preventing the image blurring from occurring.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine which scans an original and forms its reflected light on an image forming body through a lens or the like, and more particularly, by changing the scanning speed and the lens position. The present invention relates to a scaling copying machine that scales a copied image.

[0002]

2. Description of the Related Art In a general analog copying machine, a scanning speed of an original and a lens position in an optical path are moved in order to obtain a reduced copy or an enlarged copy. As a document scanning mechanism of the copying machine, a copy lamp unit or a mirror unit or a combination thereof is used in a fixed platen type copying machine, and a table glass is used in a platen moving type copying machine. Then, the image and the paper are synchronized by the operation of the document scanning mechanism.

However, in the case of a copying machine in which the image and the paper are synchronized by the operation of the document scanning mechanism as described above, the speed at which the document scanning mechanism scans the document changes during zooming, and the image changes with zooming. Therefore, in the case of reduction copying, an image in an unstable area at the start of the document scanning mechanism may be copied to the leading end portion of the paper to cause image blur.

In order to prevent such a problem, conventionally, for example, the run-up distance is set to be long so that an image is copied onto a sheet after the drive connection at the start is stable.

[0005]

However, there is a problem that setting a longer run-up distance for the document scanning function is an obstacle to downsizing of the copying machine. In particular, in the case of a fixed copyboard type copy machine, the scanning mechanism is provided inside the main body of the copy machine, which causes a serious problem.

An object of the present invention is to provide a variable-magnification copying machine which can prevent image blurring at the leading edge of the image without increasing the size of the copying machine by increasing the run-up distance.

[0007]

SUMMARY OF THE INVENTION The present invention is a copier that scans and exposes a document and forms reflected light of the document on an image forming body through a lens. It is characterized in that the lens disposed inside is moved to the image forming body side, and means for moving in parallel in the image scanning direction is provided to shift the exposure position of the document in the image scanning direction.

[0008]

FIG. 1 is a diagram for explaining the operation of the present invention, and FIG. 1 (A) shows a lens position at the time of reduction of a conventional configuration and an optical path of light imaged on an image forming body. 1B shows the lens position and the optical path of the light imaged on the image forming body at the time of reduction of the configuration according to the present invention. Although the document exposure positions P1 and P3 are shown as fixed points in the figure for simplification of description, in the case of a copying machine that scans a document by moving the optical system, the optical system must move. Thus, the document exposure positions (P1, P3) move in the opposite image scanning direction (the opposite arrow D direction). Further, in the case of a copyboard moving type copying machine, the copyboard exposure positions (P1, P3) are fixed and the copyboard moves in the direction of arrow D (image scanning direction).

In the case of the conventional configuration shown in FIG. 1A, the lens L guides the light at the document exposure position P1 to the exposure point P2 on the photoconductor during reduction.

On the other hand, in the case of the present invention shown in FIG. 1B, the lens L is translated in the image scanning direction (arrow D direction) as compared with the conventional position shown by the chain double-dashed line in the figure. Then, the document exposure position guided to the exposure point P2 moves to P3.
That is, it moves in the image scanning direction. For this reason, the start of exposure of the original document is delayed by the distance of "P3-P1", which is the same as the approach distance of the optical system being increased accordingly.

It should be noted that, at the same magnification or magnification, the lens L
It moves on the axis shown by the chain double-dashed line in FIG. 1B so as to approach the document side.

[0012]

FIG. 2 is a diagram showing the schematic construction of a variable magnification copying machine according to an embodiment of the present invention.

An original placing table 2 made of hard glass is installed on the upper surface of the copying machine main body 1. The optical system has a lamp unit 3, a mirror base 7, a lens unit 8, a mirror base 11, and a sixth mirror 12. The lamp unit 3 has a copy lamp 3a, a reflector 3b, and a first mirror 4, and is movable in the directions of arrows A and B along the lower side of the document table 2. Mirror base 7
Has a second mirror 5 and a third mirror 6, and the mirror base 11 has a fourth mirror 9 and a fifth mirror 10. The lens unit 8 houses a zoom lens and moves in the arrow E or R direction according to the copy magnification. The lens unit 8 moves in the direction of arrow E during enlargement copying, that is, in the direction away from the photoconductor (image forming body) 17, and in the direction of arrow R during reduction copying, that is, in the direction toward the photoconductor 17. Further, as will be described later, the lens unit 8 moves in parallel so as to move to the upstream side in the image scanning direction with respect to the optical axis during reduction. At the time of copying, the light of the copy lamp 3a of the lamp unit 3 exposes the document O on the document mounting table 2, and the reflected light of the document O is reflected by the mirrors 4 to 6, the zoom lens unit 8, as shown by the two-dot chain line in the figure. The photoconductor 17 is exposed through the mirrors 9, 10 and 12.

The image forming process unit in the main body 1 of the copying machine,
The configuration of the sheet feeding unit and the like is well known and will not be described.

FIG. 3 is a side view showing a support portion of the zoom lens unit 8, and FIG. 4 is a perspective view thereof.

The lens unit 8 is constructed by housing a lens 22 in a lens casing 21 having a U-shaped cross section. The lens unit 8 is mounted on the carriage portion 23. Lens unit casing 2 for lens unit 8
A long hole 21a is provided in the flat portion at both ends of the lens 1 in a direction parallel to the optical axis, and the lens unit 8 is fixed on the carriage 23 by engaging a screw 21b in the long hole 23a. At the time of fixing the screw, the elongated hole 21a can finely adjust the direction of the lens in an appropriate direction (direction parallel to the optical axis).

The carriage portion 23 is provided with moving wheels 24 at its front end portion as viewed in the drawing, and its rear end portion is fixed to the moving portion 25. A moving shaft 26 is attached to the moving portion 25, and is transmitted from outside the drawing in the arrow R direction or arrow E.
It moves in that direction by the driving force in that direction. The moving part 2
In addition to this, a known driving force transmission mechanism such as a rack and pinion, a combination gear set, or the like can be used for the movement of 5. The movement of the moving unit 25 moves the lens unit 8 in the arrow R direction or the arrow E direction. Carriage part 23
Is provided with a well-known horizontal mechanism (not shown), the carriage unit 23 and the lens unit 8 are kept horizontal and the optical axis is kept horizontal even when the wheels 24 are in the inclined portion.

On the lower side of the front side of the carriage portion 23 as viewed in the drawing, an inclined table 27 is arranged along the optical axis so that the left side is the upper side. A shaft 27a for rotation is provided near the lower end of the tilt table 27, is rotatable around the shaft 27a, and the tilt angle can be appropriately set. The inclination angle is set by inserting a screw 27c into an appropriate position of an elongated hole 27b provided in the vicinity of the upper end of the inclination table 27, and then, the housing 28 of the optical system.
It is done by screwing on.

A force in the arrow R direction or the arrow E direction is applied to the moving portion 25 from a drive system (not shown). At the time of reduction, a force in the direction of arrow R is applied to the moving unit 25. When a force in the direction of arrow R is applied to the moving unit 25, the carriage unit 23 moves up the tilt table 27, whereby the lens unit 8 moves in the direction of arrow R.
The lens unit 8 moves upward in parallel with the movement in the direction. At this time, the moving distance of the lens in the R direction changes depending on the reduction ratio, and the parallel moving distance of the lens also changes. On the other hand, when the magnification is from 1 × to 1 ×, the lens unit 8 moves down the tilt table 27 and moves horizontally along the housing 28 of the optical system.

In this case, the optical axis is fixed.

A rail or the like may be used to move the carriage 23 in addition to the wheels.

[0022]

According to the present invention, at the time of reduction, the exposure position of the document is shifted in the image scanning direction by moving the lens in parallel with the image scanning direction, and the start of exposure of the document is delayed, so that the copying machine as a whole is delayed. You will be able to get a sufficient run-up distance without increasing the size. Therefore, it is possible to prevent the occurrence of image blurring or the like at the image front end portion.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the operation of the present invention,
(A) shows a conventional example, and (B) shows a configuration example of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a variable-magnification copying machine that is an embodiment of the present invention.

FIG. 3 is a diagram showing a configuration of a lens unit portion of the variable magnification copying machine.

FIG. 4 is a perspective view showing a lens unit portion of the variable magnification copying machine.

Claims (1)

[Claims] 1. A copying machine, which scans and exposes an original and forms an image of reflected light of the original on an image forming body through a lens, wherein a lens disposed in an optical path of the reflected light of the original is imaged during reduction copying. A variable-magnification copying machine characterized in that it is provided with means for moving in parallel to the image scanning direction while moving to the forming body side, and shifting the exposure position of the document in the image scanning direction.