JP2530192B2 - Document feeder - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a document feeder which can automatically feed a document onto a platen glass of a copying machine.

[Background of the Invention]

In general, this type of document feeder includes a transport unit that presses a document against the platen glass surface with a white endless belt on the platen glass of a copying machine and transports the document by moving the belt. That is, this transport section
The endless belt covers the entire surface of the platen glass and presses the original, and the slight slack of the original conveys it while generating frictional force with an appropriate place on the original surface. For this reason, a sufficient space in the thickness direction is required for the belt to rotate, and the overall height of the main body of the device is increased, resulting in an increase in size.

The pressing force decreases over time due to belt fatigue and deterioration, and troubles due to insufficient elasticity easily occur, resulting in poor maintainability.

Had problems such as.

Therefore, the present inventor first provided a white sheet along the platen glass surface in the main body of the apparatus provided on the copying machine, and slid the original conveying roller on the platen glass surface through the through holes provided at appropriate positions of the sheet. We proposed a document transport device that can press and transport a document without contacting it and using an endless belt.

In this document feeder, the document is carried between the platen glass surface and the document pressing sheet at the transport section, and the document is fed back so as to abut against the abutting plate for exposure. However, when the document is fed back and stopped at the abutment plate, if there is a gap between the white sheet and the abutment plate, the document will slip through the top of the abutment plate and return to the paper feed side. There was a risk of doing it.

[Object of the Invention]

In view of the above points, an object of the present invention is to provide a document feeding device that can reliably stop a document without passing through the upper part of the abutting plate.

[Structure of Invention]

In order to achieve the above-mentioned object, the present invention carries in a document between a platen glass surface of a copying machine and a document pressing sheet,
In a document feeding device provided with a feeding unit capable of feeding the document back against the abutting plate, a sheet pressing means for opening and closing a gap between the sheet and the abutting plate is provided.

〔Example〕

An embodiment of the present invention will now be described with reference to the accompanying drawings.

FIG. 1 is a sectional view of a document feeder of the present invention, FIG. 2 is a sectional view of sheet pressing means, and FIG. 3 is a front view thereof. In the figure, reference numeral 1 denotes a main body of the apparatus, which is mounted on a platen glass 100 of a copying machine (not shown), and is composed of a paper feed section 2, a transport section 3, and a paper discharge section 4. There is.

The paper feeding unit 2 includes a separating mechanism 7 including a document pressing piece 5 and a paper feeding roller 6, and a stacker 8 provided on the upper portion of the main body 1.
The originals 200 stacked on the upper side can be separated from the lowermost layer one by one and fed onto the platen glass 100. The platen glass 100 has a smooth upper surface S on which the document 200 can be slid, and has an abutment plate 101 on the upper surface on the paper feed unit 2 side.

The transport unit 3 is for transporting the document 200 on the plus-ten glass 100, and includes a white sheet 9 and a document transport roller 11 as main components. The white sheet 9 is for pressing the original 200 at the time of exposure, is made of a plastic material having a high solid lubricity (PET = polyethylene terephthalate in this embodiment), and covers the entire upper surface S of the platen glass 100. The end 9a of the white sheet 9 on the side of the paper feed unit 2 is a torsion coil spring 12 described later, and the end on the side of the paper discharge unit 1 is the main body 1.
Are respectively connected to the fixed portions 1a of. In addition, three through holes 10 are provided at appropriate places along the center line of the white sheet 9 so that the end of the document conveying roller 11 projects. The through hole 10 is formed in a shogi piece shape so as to be tapered in the conveying direction so that the edge does not catch on the edge of the original 200 being conveyed (FIG. 4).

The document feed roller 11 is used to move the document 200 on the platen glass 100.
The sheet 9 is rotated so as to rotate while pressing the original 200 through the through-hole 10 so as to be conveyed by frictional force.
There are provided a total of three holes corresponding to the respective through holes 10 on the back surface side. The surface of the roller 11 is made of an elastic material having a large frictional force (for example,
Covered with rubber or plastic sponge body), through hole
The end portion is in contact with the surface S of the platen glass 100 through 10. Further, the document feeding roller 11 can be rotated forward and backward so that the final position of the document 200 can be finely adjusted during exposure.

The torsion coil spring 12 provided at the end 9a of the white sheet 9 is used to place the white sheet 9 on the platen glass when exposing the original.
100 to improve the exposure condition.
The sheet 9 is raised above 00 so as to smoothly convey the original. The sheet 9 is pulled and pulled up above the platen glass 100 unless the pressing force of the sheet 9 is applied. 13 is a pressing means, the pressing means 13 is a pressing plate 13a
And a pressing plate drive shaft 13b. Pressing plate 13a
Is a gutter-shaped member having the same width as the white sheet 9 so that the white sheet 9 can be pressed against the abutting plate 101 with a uniform force and having a smooth convex curved surface on the contact side with the sheet 9. 14 is a torque limiter, and the torque limiter 14 is
When the pressing plate 13a comes into contact with the butting plate 101 or the fixed portion 1b, the contact state is maintained and an unreasonable load is not applied. The torque limiter 14 is interposed at an appropriate position (the gear end of the drive shaft 13b in FIG. 3) of the drive transmission system that connects the pressing plate drive shaft 13b and the motor 15.

Reference numeral 16 denotes a paper discharge roller. The paper discharge roller 16 is provided on the paper discharge unit 4 of the main body 1 so that the original 200 can be sent out onto the paper discharge tray 17. 18 is a fixed protrusion, and the protrusion 18 is a white sheet 9
So that it can regulate the ascending position when the tow is raised.
It is provided at the discharge-side end of the lower surface of the discharge tray.

 Next, the operation of the present invention will be described.

First, the originals 200 are stacked on the stacker 8 provided on the upper portion of the main body 1 of the original conveying apparatus, and the ends thereof are set in the separating mechanism 7 of the paper feeding unit 2. Here, the originals 200 are separated one by one from the lowermost one by the pressing force of the original pressing piece 5 and the frictional force of the paper feed roller 6, and are fed to the conveying section 3 side.

The original 200 is fed between the platen glass 100 of the copying machine and the white sheet 9 in the conveying section 3 and the white sheet 9
The document is conveyed by a document conveying roller 11 through the through hole 10. During this time, during conveyance, the pressing plate drive shaft 13b and the motor 15
Is rotated normally and is in contact with the fixed portion 1b of the main body 1, so that the end portion 9a of the white sheet 9 is pulled by the torsion coil spring 13 and pulled up above the platen glass 100. Therefore, the document 200 does not contact the white sheet 9. On the other hand, at the time of exposure, the original 200 is once fed back and abuts against the abutting plate 101 and stops, but at this time, the pressing plate drive shaft 13 and the motor 15 reversely rotate and the pressing plate 13a turns the white sheet 9.
Is pressed to close the gap between the white sheet 9 and the abutment plate 101, so that the original 200 jumps over the abutment plate 101 and
There is no going back to the side. Further, the original 200 is pressed against the platen glass 100 by the white sheet 9 and comes into close contact therewith, so that a good exposure state is realized. Also, the pressing plate 13
When a is in contact with the fixed portion 1b of the main body 1 and the abutment plate 101, the torque limiter 14 is actuated, and a torque load exceeding a certain level is not applied. When the exposure is completed, the original 200 is discharged by the discharge rollers 16 of the discharge section 4 and is discharged from the discharge tray 17.
The layers are sequentially stacked.

〔The invention's effect〕

As described above, the present invention provides an original document conveying apparatus provided with a conveyance unit that can convey an original document between the platen glass surface of the copying machine and the original document pressing sheet and can reversely convey the original document so as to abut against the abutting plate. Since the sheet pressing means that can open and close the gap between the sheet and the abutting plate is provided, the gap between the sheet and the abutting plate can be completely closed when the document is fed back, and the original is pushed by the abutting plate. There is no risk of jumping over and returning to the paper feed section. Moreover, by configuring the sheet pressing means by the pressing plate having the same width as the sheet and the pressing plate drive shaft capable of rotating the pressing plate in the normal and reverse directions, the gap between the sheet and the abutting plate can be opened and closed only by the forward and reverse rotation of the pressing plate drive shaft. In addition, it is possible to apply a uniform pressing force to the sheet and surface-cover it. For this reason,
Not only can a trouble be prevented from occurring when the document is fed back, but also at the time of exposure, the document can be pressed against the platen glass with a uniform force to improve the image quality of the copied image.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a document feeder of the present invention, FIG. 2 is a side view showing an end portion of a white sheet and a sheet pressing means, FIG. 3 is a front view of a pressing plate and its drive system, and FIG. FIG. 3 is a front view showing the relationship between a white sheet and a document conveying roller. 1 ... Main body 2 ... Paper feeding unit 3 ... Conveying unit 4 ... Paper discharging unit 9 ... White sheet (original pressing sheet) 10 ... Perforation 11 ... Original feeding roller 13 ... Pressing means 13a .... Pressing plate 13b …… Pressing plate drive shaft 14 …… Torque limiter 15 …… Motor 100 …… Platen glass 101 …… Abutting plate 200 …… Original

Claims (1)

(57) [Claims] 1. A document transporting apparatus comprising a transporting unit capable of transporting a document between a platen glass surface of a copying machine and a document pressing sheet and feeding the document back against the abutting plate. And a sheet pressing means that can open and close the gap between the abutting plate and the abutting plate.