JPH0427876Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention is installed in copying machines, printing machines, etc.
The present invention relates to an automatic document feeder that conveys a document onto a document set surface by a conveyor belt, and particularly to an automatic document feeder equipped with a conveyor belt tension adjustment mechanism.

[Prior Art] As an automatic document feeder, one is known in which a document stored in a paper feed tray is fed out by a feeding device such as a roller, and the document is conveyed along a document set surface by a conveyor belt.

[Problems to be Solved by the Invention] This type of automatic document feeder is required to avoid mid-stop, meandering, and delay of the document during conveyance by the conveyor belt.

For this purpose, it is necessary that the conveyor belt be uniformly fitted to the document set surface with an appropriate pressure.

However, for example, if the conveyor belt stretches and loosens due to long-term use, and the height relationship between the conveyor belt and the document set surface changes, the conveyance force of the conveyor belt changes.
There is a possibility that the conveyance state of the document may become poor.

The purpose of this invention is to provide an automatic document feeder in which the conveyor belt always fits uniformly on the document set surface with an appropriate pressure to provide an appropriate conveyance force, thereby making it possible to reliably convey the document. be.

[Means for Solving the Problems] In order to achieve the above object, this invention has a frame that regulates the height of the pulley shaft of one pulley from the document setting surface, and also sets the pulley shaft parallel to the document setting surface. a guide surface that supports the pulley shaft so as to be slidable in a certain direction; an adjusting plate that supports the pulley shaft and is movable while being guided by a guide member provided on the frame; A biasing spring is provided that has a line of spring action on a straight line and biases the adjustment plate to apply tension to the conveyor belt via the pulley.

[Operation] In this invention, the biasing spring is applied via the adjustment plate in a direction that separates one pulley from the other pulley in a substantially linear direction passing through the pulley shaft and a guide member that regulates the movement direction of the adjustment plate. The pulley shaft is slidably guided on a guide surface provided on the frame in a direction parallel to the document set surface.

Therefore, even if the conveyor belt stretches due to use, for example, the height relationship between the conveyor belt and the original set surface is maintained constant, and the original can be reliably conveyed.

[Example] Hereinafter, an example of this invention will be described with reference to the drawings.

<Configuration> The illustrated one shows an automatic document feeding device that feeds a document to a main unit A such as a copying machine. In this device, a paper feed tray 1, a conveyance roller 2, and a conveyance belt 3 are arranged as shown in the figure.
The original is supplied to the original setting surface 4 of the printer.

In this example, a conveyance roller 2 and a feed roller 5 are provided as feeding means for feeding out originals from a paper feed table set 1 on which originals are stacked and accommodated. The conveyance roller 2 is on the driving side, and the feed roller 5 is on the driven side.

The conveyance roller 2 is attached to one end of a bracket 7 that is slidable about the drive shaft 6 as a fulcrum. The drive shaft 6 is connected to appropriate drive means (not shown). Reference numeral 8 denotes a pressure contact spring that presses the conveying roller 2 toward the feeding roller 5 side. The conveyance roller 2 is pressed against and separated from the feed roller 5 by the swinging of the bracket 7.

Reference numeral 9 denotes a conveyance guide that turns the fed document upside down and guides it to the conveyance belt 3.

Attach the pin 1 to the tongue piece 10 provided at the other end of the bracket 7.
The conveying roller 2 and the gate stopper 12 are connected to the conveying guide 9 by supporting the gate stopper 12 via the conveying roller 2 and the gate stopper 12.
It has begun to appear reciprocally within me.

The conveyor belt 3 is stretched between an inlet pulley 13 and an outlet pulley 14, and is placed on the document setting surface 4. Inlet side pulley 13 is frame 1
5 and is connected to a drive system (not shown).

The left and right sides of one pulley shaft 22 (in this example, the shaft of the exit pulley 14) are supported by guide surfaces 23 formed on the frame 13. This guide surface 23
supports the pulley shaft 22 so as to be slidable in a direction parallel to the document setting surface 4, and also regulates the height relationship between the pulley shaft 22 and the document setting surface 4.

Further, the left and right sides of the pulley shaft 22 are respectively engaged with engaging portions 24 provided on the adjustment plate 16.

A guide hole 18 is bored in this adjustment plate 16,
A guide pin 19 as a guide member protruding from the frame 15 is engaged with the guide hole 18, so that the adjustment plate 16 is guided by the guide hole 18 and the guide pin 19 and is movable.

The adjusting plate 16 is biased by a biasing spring 21 having a spring action line substantially on a straight line l passing through the pulley shaft 22 and the guide pin 18.
In this example, a biasing spring 21 is interposed between the guide pin 19 and a pin 20 protruding from the adjustment plate 16, which biases the pulley 14 in a direction away from the pulley 13 via the adjustment plate 16. There is.

<Operation> The apparatus configured as described above operates as follows.

A document is inserted from the paper feed tray 1, and its leading edge is brought into contact with the gate stopper 12 for alignment.

Next, the conveying roller 2 is rotated in the feeding direction in response to a paper feeding instruction signal from the main unit A, and the compression spring 8 is rotated.
Then, the conveying roller 2 is brought into pressure contact with the feed roller 5 via the bracket 7, and the document is fed to the conveying belt 3 side via the conveying guide 9.

When the specified conveyance of the document is completed, the bracket 7 swings against the compression spring 8, and the conveyance roller 2
returns to the position separated from the feed roller 5.

Next, the document is taken into the conveyor belt 3, and is conveyed by the conveyor belt 3 over the document setting surface 4.
At the same time as the document is set at the reference position, the conveyor belt 3 stops, and after exposure, the conveyor belt 3 is restarted and the document is ejected from the conveyor belt 3.

In order to properly convey the document by the conveyor belt 3, the tension of the conveyor belt 3 is adjusted as follows in this invention.

The biasing spring 21 attaches the pulley shaft 22 in the direction of separating the pulley 14 from the pulley 13 (the direction of applying tension to the belt) in the direction of a substantially straight line l passing through the pulley shaft 22 and the guide pin 19 via the adjustment plate 16. It is becoming more and more popular.

<Effects of Examples> According to the present embodiment described above, the following effects are achieved.

Since the guide surface 23 provided on the frame 15 slidably guides the pulley shaft 22 in a direction parallel to the original setting surface 4, even if the transport belt 3 stretches due to use, for example, the transport belt 3 and the original setting surface 4 are The height relationship is kept constant and the document can be transported reliably.

In addition, when copying is performed by placing a book or the like on the original setting surface 4, the pulley shaft 22 is connected to the frame 15.
the other pulley 1 along the guide surface 23 provided on the
3 to uniformly press a book or the like against the original set surface 4.

On the other hand, when the conveyor belt 3 conveys a normal document after removing a book or the like, the pulley shaft 22 slides along the guide surface 23 in a direction parallel to the document setting surface 4 to apply tension to the conveyor belt 3. Since the pulley 14 returns to the direction in which it is applied (the direction in which the pulley 14 is moved away from the pulley 13), the height relationship between the conveyance belt 3 and the document setting surface 4, that is, the pressure relationship, is not disturbed, and an appropriate conveyance force can always be applied. .

The spring action line of the biasing spring 21 is connected to the guide pin 19 that guides the moving direction of the adjustment plate 16.
Since it is on the straight line l passing through and the pulley shaft 22,
The biasing spring 21 can apply tension to the pulley shaft 22 most efficiently, and the tension of the conveyor belt 3 can always be maintained at an appropriate level.

[Effects of the invention] The invention described above provides a frame having a guide surface that regulates the height of the pulley shaft of one pulley from the document setting surface and supports the document so as to be slidable in a direction parallel to the document setting surface. an adjusting plate that supports the pulley shaft of the pulley and is movable while being guided by a guide member provided on the frame; Since it includes a biasing spring that biases the adjustment plate and applies tension to the conveyor belt via the pulley, the following effects are achieved.

The guide surface provided on the frame slidably guides the pulley shaft in a direction parallel to the document set surface, so even if the conveyor belt stretches due to use, the height relationship between the conveyor belt and the document set surface remains constant. document can be transported reliably.

In addition, when making copies by placing a book or the like on the original set surface, the pulley shaft moves along the guide surface provided on the frame in a direction approaching the pulley on the opposite side, and the book or other object is placed on the original set surface. It becomes possible to press the

On the other hand, when the conveyor belt conveys a normal document after removing books, etc., the pulley shaft slides along the guide surface in a direction parallel to the document set surface to apply tension to the conveyor belt (one side Since the pulley returns in the direction in which the pulley is separated from the pulley on the opposite side, the height relationship between the conveyance belt and the document set surface, that is, the pressure relationship, is not disturbed, and an appropriate conveyance force can always be applied.

The biasing force of the biasing spring acts on a straight line passing through the guide member that guides the movement direction of the adjustment plate and the pulley shaft, so the biasing spring can apply tension to the pulley shaft most efficiently. , the tension of the conveyor belt can always be maintained at an appropriate level.

[Brief explanation of the drawing]

FIG. 1 is an overall explanatory diagram of an embodiment of this invention. 1... Paper feed table, 2... Conveyance roller, 3... Conveyance belt, 4... Document setting surface, 5... Feed roller, 9... Conveyance guide, 13... Entrance side pulley, 14... Exit side Pulley, 15...Frame,
16... Adjustment plate, 19... Guide pin, 21...
Biasing spring.

Claims (1)

[Scope of Claim for Utility Model Registration] A paper feed tray, a feeding means for feeding out the document stored in the paper feed tray, a conveyance guide for guiding the document fed out by the feeding means to the document setting surface of the main unit, and the above-mentioned. A pair of pulleys are provided on the document set surface on the document inlet side and document outlet side, a conveyance belt is stretched between the pulleys and conveys the document on the document set surface, and one of the pulleys is provided on the document set surface. a frame having a guide surface that regulates the height of the pulley shaft from the document setting surface and supports the pulley shaft slidably in a direction parallel to the document setting surface; an adjustment plate that is movable while being guided by a guide member provided on the frame; a spring action line is substantially on a straight line passing through the pulley shaft and the guide member; An automatic document feeder comprising: a biasing spring that applies tension to the conveyor belt via a pulley.