JPS62264134A - Automatic original supply device - Google Patents

Abstract

PURPOSE:To simplify the structure of an automatic original supply device to aim at reducing the cost thereof and further to make the conveyance of an original fast, by rotating always a separating roll for originals to enable originals to run without the preceding original overlapping with the following one so that the content of each original may be read even though the originals are successively conveyed. CONSTITUTION:When a drive motor 32 is rotated, scanner reading rollers 27a, 27b are rotated so that originals 25 may run at a speed V. Further, a separating roll 21 is subjected to a torque with which the roll 21 conveys the originals at a speed W. Accordingly, the separating roll 21 conveys the preceding original 25 at the speed W, but when the original 25 is pulled by the scanning reading roller 27a, it is conveyed at the speed V. During this period the preceding original is scanned at a reading position for reading the content of the original 25, but control is made such that the following original 25 is not conveyed to the reading position Z until the above- mentioned content scanning is completed. Accordingly, it is possible to precisely and the originals 25 even though they are successively fed, and therefore the structure of the device may be simplified, thereby it is possible to aim at reducing the cost of the device and at speeding up the conveyance of the originals.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to an automatic document feeder, and more particularly to an automatic document feeder that can be applied to copying machines, facsimile machines, image scanners, and the like.

(Prior Art) An example of a conventional automatic document feeder will be described with reference to FIG. As shown in the configuration diagram of the main parts shown in FIG. 5a, 5b, and the reading rollers 5a, 5b.
A pair of pressure rollers 6a and 6b are provided facing each other, and one roller 5a in the reading roller and the separation roller 4 are rotatable together by a first transmission belt 7. The reading rollers 5a and 5b are connected to a rotating shaft 9a of a stepping motor 9 and a second and third transmission belt lo through an idle pulley 8.
, 11 and driven by a stepping motor 9.

Further, a guide plate 1 between the pair of reading rollers 5a and 5b
A slit 12 is formed in the document, and an appropriate optical system 13 scans the document through this slit 12 in order to read the contents of the document.

By the way, in the above-mentioned conventional apparatus, in order to convey the originals 3 one by one and accurately scan the contents of the originals, the separation roller 4 is equipped with a spring clutch (not shown), and the separation roller 4 is equipped with a spring clutch (not shown) to convey the originals 3 one by one and scan the contents of the originals accurately. The paper feeding drive of the separation roller 4 is once turned off by the clutch, and the document to be sent next is fed from the moment the clutch is turned on based on a command.

However, the provision of the above-mentioned clutch device complicates the structure, leading to increased costs and a decline in reliability.Also, since the clutch is engaged and disengaged, time is lost, making it impossible to increase the processing speed. Furthermore, there were other problems such as the intermittent sound of the clutch generating noise.

(Objective) It is an object of the present invention to provide an automatic document feeder that solves the above-mentioned problems of the prior art, eliminates the need for a clutch device, and is capable of continuous feeding to improve processing capacity. do.

(Structure) In order to achieve the above-mentioned object, the present invention constantly rotates a separation roller that separates the originals (driving means and the preceding original and the following original do not overlap each other, and the content of the original is moved. The present invention is characterized in that it is equipped with a control means that enables.

Hereinafter, the present invention will be specifically explained based on preferred embodiments.

1st 'l! 1 shows a front view of the first embodiment of the present invention.

In the figure, a separation roller 21 is fixed to a separation roller shaft 22 via a one-way clutch 23, and a forest-like separation member 24 is in elastic contact with the upper part.

The document 2 is placed at the joint between the separating member 24 and the separating roller 21.
5 is located at the end of the conveyance path 26 along which the conveyance path 26 is conveyed. On the right side of the separation roller 21 is a pair of scanner reading rollers 27a.
, 27b are arranged, and this scanner reading roller 2
Pressure ports 28a and 28b are in elastic contact with 7a and 27b, respectively. a pair of scanner reading rollers 27a;
2? A sensor 29 for detecting the passage of the original 25 is provided between b.
A reading section 30 for reading the contents of the document 2''5 is provided.

Further, pulleys 31a and 31b are fixed to the scanner reading rollers 27a and 27b and the separation roller 21, respectively, and a drive pulley 33 fixed to the rotating shaft 32a of the drive motor 32 and a pulley 31b of the scanner reading rollers 27a and 27b are connected to each other. They are connected by a first belt 34,
Also, the pulley 3 of one scanner reading roller 27a
1b and the pulley 31a'' of the separation roller 21 are connected to the second belt 3.
It is connected at 5. - Here, in the present invention, since the separation roller 21 is kept rotating at all times, the following conditions are required. That is, even if the rear end of the preceding document 25 is separated from the separating roller 21, the separating roller 21 continues to rotate, so that the succeeding document 25 is separated and conveyed without leaving an interval. Here, if the subsequent document 25 is conveyed at a speed W to the scanner reading roller 27a, and then conveyed from the scanner reading roller 27a at a speed v (vow),
During the distance aX from the separation roller 21 to the scanner reading roller 27a, the difference between the trailing edge of the preceding document and the leading edge of the trailing document is (v −w / v) ・X ・−・−・・−(a
).

Here, the sensor 29 detects the leading edge and the trailing edge of the document 25 and issues a signal that serves as a reference for starting or ending reading at an appropriate timing. The difference from the tip of , that is, the value (a) above, is
If the distance between the sensor 29 and the reading position NZ is smaller than 111Y, control becomes difficult, so (v-w/v)" By establishing the relationship in equation b), there is no need to turn on and off the rotation of the separation roller 21 as in the conventional device.

To explain the operation of the first embodiment described above, the drive motor 3
2, the driving force is applied to the scanner reading roller 2.
7a, 2? b is transmitted by the first belt 34, and the scanner reading rollers 27a and 27b rotate so as to convey the document 25 at the speed V. Also, separation roller 21
A rotational force for conveying the original 25 to the speed W is applied by the second belt 35 .

Therefore, the preceding original 25 is conveyed at a speed W by the separation roller 21, but when the preceding original 25 is drawn in by the scanner reading roller 27a, it is then conveyed at a speed V. During this time, the content of the preceding document 25 is scanned by a scanner (not shown) at the reading position Z. However, since the distance Y between the sensor 29 and the reading position Z satisfies the condition of equation (b), the preceding document 25 is scanned by the scanner (not shown). The trailing original 25 is not conveyed to the reading position Z until the content scanning of the original 25 is completed.

Therefore, without controlling the conveyance of the document 25 by turning on and off the separation roller 21, the contents of the document can be read accurately one by one.

Next, FIG. 2 shows a front view of a second embodiment of the present invention, in which members corresponding to those described in the first embodiment shown in FIG. 1 are given the same reference numerals.

The difference between the second embodiment and the first embodiment is that a sensor 40 for detecting the trailing edge of the document and a sensor 41 for detecting the leading edge of the document are provided to clearly distinguish the preceding document from the following document and to detect the document at the reading position Z. This configuration allows the scanner to accurately scan the content.

That is, in FIG. 2, a bent portion 42 is formed in the conveyance path 26 between the separation roller 21 and one of the scanner reading rollers 27a, and the leading edge of the trailing original 25 and the rear end of the preceding original 25 are formed in the bent portion 42. and are clearly separated. A document trailing edge detection sensor 40 for detecting the trailing edge of the document 25 is disposed in the bent portion 42. In this embodiment, a light receiving element 40a is used as the document trailing edge detection sensor 40.
The light-emitting element 40b and the light-emitting element 40b face each other, and are of a transmissive type in which the trailing edge is detected by blocking the optical path by the document 25. Furthermore, a sensor 41 for detecting the leading edge of a document is arranged between one scanner reading roller 27a and the reading section 30.

By providing the document control means as described above, even if the separation roller 21 is continuously rotated, there is no possibility that there is no gap between the preceding document and the following document and the sensor cannot detect the document. The document 25 that is continuously conveyed is clearly divided into the trailing edge of the preceding document and the leading edge of the trailing document at the bending portion 42, so that the document trailing edge detection sensor 40 can accurately detect the trailing edge of the document. .

Therefore, by detecting the trailing edge of each document 25 being conveyed, the content scanning of the preceding document 25 by the scanner is completed after a predetermined number of steps or a predetermined distance has passed after this detection. This prevents the following document and the preceding document from overlapping and being read and scanned as one document.

Although a light transmission type sensor is shown as the document trailing edge detection sensor 40, a known reflection type sensor or actuator type sensor may also be used.

Further, in both the first and second embodiments, a mechanism for separating the document 25 is shown that includes a separating roller 21 and a rubber plate-shaped separating member 24, but the separating member 24 is not limited to that of this embodiment.

Furthermore, the first. In the second embodiment, the drive motor 32 drives the scanner reading rollers 27a, 27b and the separation roller 2.
Although a pulley and a belt are used to transmit the driving force to the motor 1, the transmission means is not particularly limited, and gears may also be used.

(Effects) As explained above, the present invention allows the content of the document to be read accurately even if the document is conveyed continuously by constantly rotating the separation rollers. It is possible to provide an automatic document feeder that does not require a stopping clutch, has a simple configuration, reduces costs, and has effects such as speeding up the conveyance process.

[Brief explanation of drawings]

FIG. 1 is a front view showing a first embodiment of the present invention, FIG. 2 is a front view showing a second embodiment of the present invention, and FIG. 3 is a front view showing a conventional example. 21... Separation roller, 25... Document, 32... Drive means, 27a, 27b, 29.31a, 31b, 34°35.40.41.42... Control means.

Claims (1)

[Claims] In an automatic document feeder that transports documents one sheet at a time and scans the contents of the document, a driving means that constantly rotates separation rollers that separate the documents overlaps the preceding and following documents. 1. An automatic document feeder comprising: a control means that enables scanning of document contents without any interference.