JPS6274851A - Automatic document feed device - Google Patents

Abstract

PURPOSE:To make the entire device small, by feeding a document by a plurality of rollers of a small diameter disposed in a loop-shaped feed passage of a document inverting unit. CONSTITUTION:A document feed unit 20 is provided with a document inverting unit 25b located at the right hand side of a platen glass 11 for inverting the front and the back of a document D through a pair of loop-shaped feed passage and the document inverting unit 25b has a group of rollers 23b-d rotating in a direction of the arrow disposed at its essential positions. More specifically, since a cross section of the document inverting unit 25b is formed by a slit type feed passage, it can be constructed of the drive rollers 23b-d of a relatively smaller diameter. With such an arrangement, a large space can be formed inside the document inverting unit 25b and a drive motor M is contained in the space. Since the space can contain the motor M and other drive members in such a manner, the entire device can be made smaller.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an automatic document feeder used in addition to a recording device such as an electrophotographic copying machine.

[Conventional technology]

An automated document feeder (ADF') has already been provided as a device that can efficiently supply documents to be copied to a recording device even in an unattended state. Functionality was limited to those that made copies.

On the other hand, with the recent development of recording devices that can make continuous copies on the front and back sides of recording paper, the need for ADFs that can copy double-sided originals is increasing. Many mechanisms have been devised. Regarding them, JP-A No. 59-216159, JP-A-53-112738, Utility Model Application No. 59-4
Proposals such as Publication No. 548, Japanese Unexamined Patent Publication No. 60-8834, etc.□
There is.

[Problem that the invention seeks to solve]

In most of these proposals, the document is transported into a document reversing unit consisting of a loop-shaped conveyance path, and is circulated to reverse the front and back sides, but generally the length of the conveyance path is Since it is made longer than the longest original to be used, the original reversal section is quite large.

However, as in the example proposed in the above-mentioned Japanese Utility Model Publication No. 59-4548, the document is conveyed in the document reversing section by pressing against the large-diameter drive roller disposed at the center of the conveyance path and its peripheral surface. Since this is carried out by clamping a plurality of pressure rollers that rotate following the rollers, most of the space in the document reversing section is occupied by the driving rollers, making it difficult to accommodate other mechanical components. It is in a state where it cannot be used.

As a result of solving this problem and improving the present invention, the present invention has an automatic document reversing section that can house a drive roller and a large mechanical member such as a drive motor in the loop-shaped conveyance path described above. The purpose is to provide a transport device.

[Means for solving problems]

The above object is to provide an automatic document feeder equipped with a document reversing section consisting of a loop-shaped conveyance path for reversing the front and back of a document, in which the document is conveyed by a plurality of small-diameter conveyance rollers disposed on the conveyance path of the document reversal section. This is achieved by an automatic document feeder characterized by the following.

〔Example〕

An embodiment of the invention is shown in FIGS. 1 and 2.

The figure shows the recording apparatus main body 10 viewed from the front with broken lines. On the upper surface of the apparatus main body 10, there is an automatic document feeder (hereinafter referred to as AD) of the present invention whose outline is also indicated by a broken line.
The ADF 20 (referred to as F) is mounted in a structure that can be opened to the rear side by supporting it with a hinge etc. In the case of the figure, the ADF 2
0 is tilted toward the front and the document transport belt 30 is attached to the main body 1 of the apparatus.
The situation is such that the platen glass 11 provided on the top of 0 is pressed against the platen glass 11.

That is, the ADF 20 is capable of automatically feeding a document using a conveying mechanism to be described below, but it also functions as a normal platen cover by manually opening and closing the entire ADF 20.

The document conveyance mechanism in the ADF 20 includes conveyance members shown in FIG. 1 between substrates A and B provided inside the apparatus, and drives for rotating the conveyance members on the back side of substrate A. Arrange the members (shown in double-dot chain in Figure 1), and connect the 1 drive motor M.
It is configured to be driven and rotated by the power of the

There is a document feed tray 40 at the top of the ADF 20, which is used to stack documents, and when the copy button is pressed, the ADF
Each conveyance mechanism is operated by the motor in F20, and after the feed roller 21 presses the top surface of the leading edge of the document tray with its own weight, it begins to rotate in the direction of the arrow and guides the document tray with the top first surface as the top surface. Plate 24 a and send it out.

Continued (・For original document processing, the processing belt 22a and the processing roller 2
2b, only the uppermost sheet passes through the guide plate 24b, and when its tip reaches the paper feed roller 23a, which rotates in the direction of the arrow, a detection signal from a sensor (not shown) causes the feed roller to move. The power transmission to the paper feed roller 23a is cut off by the clutch C, and the rotation thereof is made free. The document sheet that is now transported by the paper feed roller 23a is transported inside the U-shaped guide section 5a. As a result, the front and back sides are reversed, and the guide portion 25 a
The conveyance roller 28a and the driven roller 28 rotate clockwise while removing the shielding member 27 provided at the exit of the document tray with the tip of the document tray.
It reaches the conveyor belt 30, which is stretched across the gap between b and 30, and continues to be conveyed by its frictional force.

When the document is conveyed by the conveyor belt 30 while sliding to the left on the platen glass 11, its left end comes into contact with the document stopper member 12 provided on the left side edge of the platen glass 11 and stops. Immediately after this, the rotation of the conveyance roller 28a is temporarily stopped in response to a signal outputted from the control section after a predetermined time delay by the sensor described above. In other words, the conveying roller 28a will stop a predetermined time later than the time required from when the sensor detects the document stain to when the document reaches the document stomper member.

Note that the document stopper member does not necessarily need to be installed on the recording apparatus main body side, and may be installed on the ADF side.

In this state, the document is pressed against the platen glass 11 by the conveyor belt 30, which is under the weight of a plurality of driven rotating pressure rollers 29, and the exposure of the first side is started, after which the image is transferred through a well-known process. One-sided copying is completed by forming and transferring to recording paper.

Furthermore, in ADH'20, the platen glass 1
A document reversing section 25b is provided on the right side of the document reversing section 25b for reversing the front and back of the document tray using a loop-shaped conveyance path formed by a pair of thin metal plates, resin plates, etc., and one end thereof is connected to the guide section 25a described above. It is configured such that it is opened and connected, and the other end is opened at the right edge of the platen glass 11.

A group of conveying rollers 23b123C123d rotating in the direction of the arrow is arranged at important points in the reversing section 25b, and near the opening/portion facing the platen glass 11, a roller group 23b123C123d is arranged to detect a document passing through the reversing section 25b. Light emitting section 26 for
A photosensor 26 consisting of a light receiving section 26a and a light receiving section 26b is arranged.

That is, in the automatic document feeder of the present invention, since the cross section of the document reversing section 25b is formed by a slit-type conveyance path, the drive roller pair having a relatively small outer diameter is used to transport the conveyance rollers 23b, 23c, 23d
These conveyance rollers 23b,
By arranging the 23C 123d in accordance with the shape of the conveyance path, for example as shown in FIG. 1, the document in the reversing section 25b is reliably conveyed.

On the other hand, the original document whose first side has been exposed by the above-described process is transported rightward on the platen glass 11 by the transport belt 30 as the transport roller 28a starts rotating counterclockwise in synchronization with the end of exposure. Ru.

The right end of the conveyed original document is blocked by the shielding member 27, so that it does not enter the guide section 25a and is therefore sent into the reversing section 25b.

Therefore, the document is transported by the transport rollers 23d, 23c, and 23b.
After going around the reversing part 25b counterclockwise in the order of
5a, the shielding member 27 is removed again and the document is fed onto the platen glass 11. However, since the path length of the reversing section 25b is set in advance to be longer than the maximum length of the various document trays used, The left end, that is, the rear end of the transport roller 28a has already passed through the light beam of the photosensor 26, and the rotation of the transport roller 28a is switched clockwise again based on that signal.

Therefore, the document sent onto the platen glass 11 is turned upside down by passing through the reversing section 25b, and the back surface, that is, the second surface, faces the platen glass 11 until it comes into contact with the document stopper member 12 by the conveyor belt 30. transported.

Then, the rotation of the conveying roller 28a is stopped again in response to a signal issued from the photosensor 26 after a predetermined time delay. In other words, the conveying roller 28a stops a predetermined time later than the time required from when the document is detected by the photosensor 26 until it reaches the document stopper member 12.

Meanwhile, in the main body 10 of the apparatus, the recording paper that has undergone single-sided copying has been fixed, is turned over, and is ready to be transferred on the back side. Exposure, image formation, and transfer are performed on the back side, ie, the second side, of the original document.

After completing the exposure of the back side of the document plate, the solenoid etc.

The document stopper member 12 is retracted by the action of the document stopper member 12, and then the conveyance roller 28a starts rotating clockwise again. As copying is repeated, the originals are stacked one after another and die.

The functions of the respective conveying members are operated by a driving motor M as a driving means for document conveying, which will be described next, and each driving member rotated by the driving motor M.

Generally, the driving motor M is large in size due to its heavy load and is equipped with a reduction gear device, so it requires a large space within the device to house it. In the conveyance device, as described above, by configuring the above-mentioned reversing roller group using drive rollers with small outer diameter dimensions, it is possible to form a large space inside the document reversing section 25b, and this space can be effectively used. One way to utilize this is to accommodate the drive motor M.

Therefore, the shut of the driving motor M is configured to pass through the substrate A and transmit power to each driving member assembled on the back surface of the substrate A.

In other words, the rotation of the driving motor M is transmitted at a reduced speed from the pulley P1 to the pulley P2 via the timing belt to drive the conveying roller 28 &, and at the same time, the rotation of the drive motor M is transmitted to the pulley 3 via the timing belt. It is transmitted to pulley 4.

The pulley 3 drives the paper feed roller na, which is coaxially integrated, and further drives the reversing rollers 23b, 23c, and 23d via a gear G1 or G2. The gears G1 and Boo') are engaged only in mutually opposite rotational directions between the gears IJPGI and PG2, which are mounted on the same axis.
A one-sided clutch is provided in which either one of the gear G1 or the gear G2 and the gear IJPC2 are coaxially integrated, and the conveying rollers 23b, 23c, and 23d are rotated regardless of the rotational direction of the paper feed roller 23a. Both can only be rotated counterclockwise.

All of the driving members except for the driving motor M are small-sized members, and only occupy a small depth on the back side of the substrate, thereby making the device 20 small and easy to handle.

Note that the space formed inside the reversing portion 25b can accommodate members other than the aforementioned drive motor M, and is extremely useful for making the device 20 more compact.

〔Effect of the invention〕

According to the present invention, a space can be formed inside the document reversing section by using a structure in which the document reversing section is formed in a loop shape and a transport guide having a slit-like cross section is provided with a plurality of small-diameter transport rollers. It is possible to accommodate a drive motor or other drive members in the space, thereby making it possible to provide an automatic document conveying device whose entire device is compact and easy to handle.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional configuration diagram of an automatic document feeder according to the present invention. FIG. 2 is a plan view of essential parts of the device. 20...Automatic document feeder (ADF) 2...Feeding roller 23a...Paper feeding roller 23b~23
d... Conveyance roller 25 b... Reversing section 28 &... Conveyance roller 30... Conveyance belt M... Drive motor G1, G2... Gear

Claims (2)

[Claims] (1) An automatic document feeder equipped with a document reversing section consisting of a loop-shaped conveyance path for reversing the front and back of the document, characterized in that a plurality of small-diameter conveyance rollers are disposed on the conveyance path of the document reversal section. Automatic document feeder. (2) The automatic document conveying apparatus according to claim 1, further comprising a drive source for conveying the document installed inside the conveyance path.