JPH0656471B2 - Exposure equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is capable of moving an exposure optical system to scan a document on a stationary document, or fixing the exposure optical system to move a document to scan a document. The present invention relates to the improvement of the exposure device of a copying machine that enables both.

[Prior art]

In a copying machine of the type that scans a stationary original by the movement of the exposure optical system to make a copy, naturally, the entire surface of the image cannot be scanned for a sheet original longer than the movement distance of the exposure optical system. Therefore, copying is impossible.

In such a case, in a copying machine equipped with a sheet document feeder, the exposure optical system is stopped at a fixed position and turned on,
With the document stopper retracted from the document placement surface, the sheet document is continuously conveyed by the conveyor belt to the exposure section for scanning, thereby enabling copying of the entire original image. There is. According to this method
Since the scanned sheet portion is sequentially sent out of the copying machine from the original mounting glass surface, it is possible to scan the original document having a length larger than the specified size.

1 and 2 are explanatory views showing this state.

A document placing table 2 corresponding to the size of a sheet document of a prescribed size is fixedly mounted on the upper portion of the copying apparatus 1, and a transport belt 3a rotated clockwise by drive rollers R1 and R2 on the upper surface thereof and the transport. A conveyance device 3 is provided, which includes a feed roller 3b that feeds a sheet document to the belt 3a and a discharge belt 3c that discharges the sheet document from the conveyance belt 3a.

Below the document mounting glass 2, a first mirror unit 5a and an second mirror unit 5 having an exposure lamp L are provided.
Further, an exposure optical system 5 including a projection lens 5c and a reflection mirror 5d is arranged, and the first mirror unit 5 is provided.
a is a speed related to the peripheral speed of the photosensitive drum 6, that is, the speed of the first mirror unit 5a is V ₂ , the peripheral speed of the photosensitive drum 6 is V ₃ , and the copying magnification is n, V ₂ × n = V ₃ and the second mirror unit 5b has a speed 1/2 that of 1/2.
Both of them can be moved linearly to the right by V ₂ in parallel with the original placing glass 2. Further, a document stopper 4 is provided at a position facing the left end of the document placing glass 2, and when a sheet document having a size equal to or shorter than a prescribed size is to be copied, it is projected on the document placing surface for stopping the sheet document. , It is possible to evacuate downward by the ejection signal. However, when copying a sheet original longer than the specified size, it is possible to keep the evacuated state by performing a special operation. ing.

In such a copying apparatus, defined size equal to or case of copying short a sheet original D ₁ than, the sheet document D ₁ that is inserted into the feed roller 3b as shown in FIG. 1 is an original placing glass 2 by the conveyor belt 3a It moves upward in the left direction and comes into contact with the document stopper 4 to stop.

Photoreceptor thereafter the first mirror unit 5a and the second mirror unit 5b rotates with the peripheral velocity of V ₃ via the reflection mirror 5d by the image projection lens 5c of the document surface by exposing and scanning while moving to the broken line position An image is formed around the drum 6.

When the exposure scanning is completed in this way, the exposure lamp L is turned off and the first and second mirror units 5a and 5b return to the positions shown by the solid lines, but in conjunction with this, the original stopper 4 retracts downward. After the sheet document D ₁ is again moved by the conveyor belt 3a and discharged through the conveyor belt 3c to the outside of the apparatus, it again projects to the document mounting surface to prepare for the next sheet document. ing.

On the other hand, when copying a sheet original D ₂ having a length exceeding the specified size, the sheet original D ₂ inserted into the feed roller 3b as shown in FIG. ₂ is moved leftward on the original placing glass 2 by the conveyor belt 3a. Moved to and transported at a constant speed V ₂ ,
It is discharged to the outside of the apparatus by the conveyor belt 3c. First first
In the figure, the first mirror unit 5a and the second mirror unit 5b having the moved exposure lamp L are both stopped at a fixed position, and the exposure optical system is stopped.
An image is formed on the peripheral surface of the photosensitive drum 6 which rotates at a peripheral speed of V ₃ .

Here, the fixed position where the exposure optical system is stopped may be anywhere as long as it is within the scanning range of the exposure optical system, but the conventional position is near the right side edge of the document placing glass 2 as shown in FIG. First mirror unit 5a having exposure lamp L on
And the sheet document D ₂ is conveyed. The sheet document D ₂ is transported by the feed roller 3b, the transport belt 3a, and the paper discharge roller 3c, while the document D ₂ is transported by the feed roller 3b and the paper discharge roller 3c by a pair of rollers sandwiching pressure contact. Contrary to this, the conveyance belt 3a conveys it on the fixed document placing glass 2. Since the conveyance is somewhat uncertain compared to the rollers, it is arranged near the feed roller 3b. It is a thing.

On the other hand, when changing the magnification, there are a method of changing the focal length of the projection lens and a method of simultaneously moving the projection lens and changing the optical path length. In the fixed position of the exposure optical system as shown in FIG. 2, the range of magnification change is limited. In particular, when the magnification is very wide, the projection lens 5c moves to the second mirror unit 5b side, which is greatly restricted.

[Object of the Invention]

The present invention relates to an exposure of a copying machine in which an exposure optical system can be moved by fixing a document and a document can be moved by fixing the exposure optical system so that a variable magnification range can be freely set. The purpose is to provide a device.

[Structure of Invention]

The present invention is intended to achieve the above object. The present invention provides an exposure light source for exposing a document by providing a movable document stopper at an end of a document placing glass on which a document is placed or moved. And a first mirror unit having a mirror, and a second mirror unit including two mirrors for changing the optical path,
In an exposure device having a projection lens, a document stopped by a document stopper is moved by a first mirror unit, a second mirror unit that moves in the same direction at a speed half that speed, and a projection lens that is fixedly positioned. Having a first exposure mode in which image exposure is performed on the photoconductor, variable magnification copying is possible by changing the fixed position of the projection lens and the initial position of the second mirror unit, and the stopper is moved to move. The optical system is fixed to the original to be
(EN) Provided is an exposure apparatus characterized in that a fixed position of a mirror unit is within a movement width at the maximum magnification in variable magnification copying, and has a second exposure mode for performing image exposure on a photoconductor. .

〔Example〕

FIG. 3 shows only the exposure apparatus section shown in FIG. 2 taken out, and the part number and the part name follow the above description. The letter I added to the head indicates the home position (initial stop position) of the moving part in the method of scanning the exposure optical system in the same-size copying.

On the other hand, II5a shows the fixing position of the first mirror unit when the above-mentioned conventional exposure optical system is fixed.

In this embodiment, the projection lens 5c is moved and the optical path length is changed upon zooming.
III5c indicates the position of the projection lens when the image is reduced, and I
V5c indicates the position of the projection lens when the image is enlarged. As is well known, since the optical path length at the time of reduction or expansion is longer than that at the same magnification, III (IV) 5b indicates the position of the second mirror unit at the time of reduction or expansion.

When the image is reduced or enlarged at the position of the first mirror unit indicated by II5a which has been conventionally used, when the image is reduced or enlarged, the second mirror unit 5b moves the first mirror unit 5a by a moving amount (that is, from I5a). II5a) is moved by half, so that the second mirror unit 5b is II5b
It will be located at the position. Therefore, the exposure optical system 5c is located at the position III5c at the time of reduction, so that it does not matter at all, but it is located at the position IV5c at the time of expansion, so that it overlaps the second mirror unit 5b located at the above-mentioned II5b. That is, image enlargement cannot be performed at the conventional first mirror unit fixing position II5a.

Here, if the first mirror unit 5a is set to the fixed position V5a, the second mirror unit 5b at the time of contraction or expansion is V
Since the stop position is 5b, the second mirror unit stop position V5b does not overlap even if the projection lens 5c is in the contraction position III5c or the enlargement position IV5c.

According to the present invention, the fixed position of the first mirror unit is set within the movement width at the maximum magnification in the variable magnification copy shown by the arrow 50 so that the image can be enlarged or reduced in addition to the original size. is there.

〔The invention's effect〕

As described above, by moving and fixing the exposure light source and the optical path conversion mirror within the range that does not hinder the movement of the lens during zooming (indicated by the arrow 50), the image can be freely moved even in an exposure apparatus of the type that moves a document. You can now zoom in and out.

Of course, the first optical system for moving a document
As a fixed position of the mirror unit 5a, II5 at the same magnification
It is also possible to set the position to a and switch the first mirror unit 50 to be fixed within the range indicated by the arrow 50 at the time of zooming.
Included in the present invention.

[Brief description of drawings]

FIG. 1 and FIG. 2 are structural views showing the usage mode of the copying machine to which the present invention is applied, and FIG. 3 is an explanatory view of this exposure device section. DESCRIPTION OF SYMBOLS 1 ... Copying apparatus, 2 ... Original placing table 3a ... Conveying belt, 5a ... First mirror unit 5b ... Second mirror unit, 5c ... Projection lens 6 ... Photosensitive drum

Claims (1)

[Claims] 1. A movable document stopper (4) is provided at an end of a document placing glass (2) on which a document is placed or moved, and which has an exposure light source for performing image exposure of the document and a mirror. 1
In an exposure device having a mirror unit (5a), a second mirror unit (5b) consisting of two mirrors for changing the optical path, and a projection lens (5c), for an original stopped by an original stopper (4) Is an image exposure on a photoconductor (6) which is moved by a first mirror unit (5a), a second mirror unit (5b) which moves in the same direction at a speed half that of the first mirror unit (5a), and a projection lens (5c) which is fixedly positioned. Has a first exposure mode for changing the fixed position of the projection lens (5c) and the initial position of the second mirror unit (5b) to enable variable magnification copying. The optical system is fixed to the retracted and moving original, and the fixed position of the first mirror unit (5a) is within the movement width at the maximum magnification in variable magnification copying, and the image is formed on the photoconductor (6). Exposure Cormorants exposure apparatus characterized by a second exposure mode.