JPS62105009A - Original conveyor - Google Patents

Abstract

PURPOSE:To detect original size by identifying the original width with respect to the conveying direction of the original passing on a conveyance path by a detection means and calculating the length of the original in the conveying direction by the number of times of changeover of exciting phase of a motor. CONSTITUTION:When a sheet of original 12 or plural sheets of originals 12 in layers are placed on an original paper feeding stand 11, the originals are sent till a separate roller 15 by a paper feeding roller 14. Then, when the uppermost original 12 is sent till an alighning roller 19 by the roller 15 and the original 12 is detected by an original sensor 13a arranged at the position just before this, the roller 15 is stopped after the prescribed rotation. The original sensor 13a is arranged at the center approximately with respect to the direction of the conveyance path width and responds with respect to the whole of originals 12. Further, a width sensor 13b is arranged deviating by the prescribed quantity to one side with respect to the direction of the conveyance path width and is actuated when the original 12 having over the prescribed width passes through the conveyance path. Further, after the original 12 is conveyed till the exposure position 18 on the glass surface 17 and exposed the number of times required by a copying machine main body 16, a copy is made. When the exposure is finished, the rollers 14 and 15 are actuated and the original 12 is shifted to the next conveyance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a document conveying device installed in an image forming apparatus such as a copying machine.

[Technical Background of the Invention and Problems Therewith] Conventionally, as a method for detecting 1-nize of a document in a document conveyance device, a method using a document conveyance device as shown in FIG. 5 is known. This document conveying device is configured so that a plurality of switches 4a, 4b, and 4C are set to 0N10FF by moving the document guide 2 on the document feed table 1 in accordance with the document 3. This makes it possible to detect whether the original is nice.

However, this document conveying device has the following problems.

(1) It is not possible to detect whether the document is placed vertically or horizontally.

(2) The number of switches required is equal to the number of types of originals used.

(3) Erroneous detection will occur if the document guide is not set correctly.

(4) If originals of different sizes are used at the same time, only large originals can be detected correctly.

[Object of the Invention] The present invention has been made in response to the above-mentioned circumstances, and an object of the present invention is to provide a document conveying device that can accurately detect the size of each document with a simple configuration.

[Summary of the Invention] In order to achieve the above object, the present invention provides a document conveyance device that includes a conveyance path through which a document is conveyed, a motor that is driven by switching excitation phases to convey the document, and a motor that is driven by switching excitation phases to convey the document. A counter for counting switching of the excitation phase, a detection means for detecting a document passing on the conveyance path, and a control means for operating the counter while the detection means detects passage of the document. It is something.

According to the present invention, the detection means identifies the document width in the conveyance direction of the document passing on the conveyance path, and the length of the document in the conveyance direction is calculated based on the number of times the excitation phase of the motor is switched. The size can be detected.

[Embodiments of the invention] The present invention will be described below with reference to one embodiment.

FIG. 4 shows a document conveying device for an electronic copying machine according to an embodiment of the present invention.

This document conveying device includes a document feed table 11 on which a document is placed.
A paper feed roller 14 and a separation roller 1 separate the document 12 from the document feed table 11 and convey it to the detection means 13.
5, and place this original 12 on the glass surface 1 of the electronic copying machine main body 16.
Aligning roller 1 conveyed to exposure position 18 on 7
9, a conveyor belt 20, a paper ejection roller 21 for ejecting the exposed original 12, and a document holder 22 for storing the ejected original 12.

The detection means 13 includes a document sensor 13a disposed immediately before the aligning roller 19 and approximately at the center in the width direction of the conveyance path, and a document sensor 13a located behind the document sensor 13a in the conveyance direction and in the width direction of the conveyance path. 108 from the center of the conveyance path
It consists of width sensors 13b arranged at positions shifted by ~125 mm.

Further, the conveyance belt 20, the paper ejection roller 21, and the document receiver 22 are integrated to form a belt conveyance section 23.

Next, the document conveying operation of this document conveying device will be explained.

First, one or more original documents 12 are stacked on the document feed tray 11, and then the document 12 is sent to the separation roller 15 by the feed roller 14.

Next, the uppermost document among the documents 12 is sent to the aligning roller 19 by the separating roller 15 .

When the original 12 is detected by the original sensor 13a placed immediately in front of the aligning roller 19, the separation roller 15 is stopped after rotating for a certain period of time.

Since this document sensor 13a is disposed approximately at the center in the width direction of the conveyance path, it responds to all documents "2". On the other hand, since the width sensor 13b is disposed offset by a certain amount to one side with respect to the width direction of the conveyance path, the width sensor 13b is operated when a document having a certain width or more passes through the conveyance path.

Roughly, the original document 12 is conveyed to an exposure position 18 on a glass surface 17 by rotation of an aligning roller 19 and a conveyor belt 20 .

Next, after the copying machine main body 16 performs a necessary number of exposures, a copy is generated. When this exposure is completed, the paper feed roller 14 and separation roller 15 are operated to start conveying the next original 12, and the exposed original 12 is ejected to the original document receiver 22 through the ejection roller 21. be done.

FIG. 1 is a block diagram of the control system of this document conveying device.

The control system of this document feeding device includes a brushless motor 24 that drives the feeding system of this document feeding device, a motor drive unit 25 that drives this brushless motor 24, and controls that calculate the document size, control document feeding, etc. 26.

Roughly, the motor drive unit 25 is a three-way motor in the brushless motor 24.
A position detection circuit 25a that detects the position of the motor by two Hall elements 24a, 124b and 24c, and a rotation of 0N10.
A rotation control circuit 25b for switching between FF and rotation direction, a drive logic circuit 25G for switching the excitation phase of the brushless motor 24 depending on the position of the motor and the state of the rotation control circuit 25b, and a drive logic circuit 25C.
It is composed of a driver circuit 25d that causes current to flow to the excitation coil 24d according to the output of the excitation coil 24d.

The control unit 26 also includes a program memory 26a in which instructions are stored in advance, a data memory 26b, and a Cable controller that sequentially executes the instructions stored in the program memory 26a.
It is composed of a PU 26G and an input/output interface 26d.

Furthermore, the input/output interface 26d includes an interface 1 with the copying machine main body 16 in addition to the motor drive unit 25.
6a, a solenoid 27, a control panel 28, an empty switch 29 that detects the presence or absence of the document 12 on the document feed tray 11, a set switch 30 that detects the opening/closing of the belt conveyance section 23, and a detection of document ejection. The paper ejection switch 31 is connected to the document sensor 13a and the width sensor 13b described above.

The conveyance system of this embodiment is driven by a single brushless motor, and when the brushless motor 24 rotates in the forward direction (CW), the paper feed roller 14 and the separation roller 15 rotate in the reverse direction (CCW).
At the time, aligning roller 19, conveyor belt 20. and a paper discharge roller 21 are configured to rotate.

Further, from the position detection circuit 25a, the Hall elements 24a, 2
One pulse is output each time the voltages of 4b and 24c change. This pulse is generated 12 times per rotation of the rotor, and by counting this number, the amount of rotation of the motor, that is, the amount of document feeding can be calculated. This pulse signal is counted by the control section 26 to control the amount of document feed.

FIG. 2 is a circuit diagram of a document length detection circuit for detecting the document length within the input/output interface 26d.

This circuit is comprised of a counter 32 that counts the amount of rotation of the brushless motor 24, and an AND gate 33 that takes the logical product of a pulse signal from the position detection circuit 25a and a signal from a sensor or the like.

Next, detection of document size in this embodiment will be explained.

First, a pulse signal generated by the position detection circuit 25a is transmitted through an AND gate 33 to a counter 32 of a document length detection circuit. The AND gate 33 allows the counter 32 to be activated by the pulse signal only when the brushless motor 24 is rotating in reverse and the document sensor 13a detects the document 12. As a result, the counter 3'2 stores the amount of rotation of the brushless motor 24 required for the original @12 to pass through the original sensor 13a, and can be converted to the length of the original.

The width of the document 12 is determined by the width sensor 13b when the document sensor 13a detects the trailing edge of the document 12. In other words, when the document sensor 13a detects the trailing edge of the document 12, it changes from "document present" to "no document". By reading the status, it is determined whether the document width is larger or smaller than a certain value.

At this point, the two pieces of information for determining whether the document is nice are available, so the CPU 26G then determines the size of the document based on the combination of these pieces of information.

That is, the program memory 26a of the control unit 26 stores in advance a counter value and a size code, which is a standard document size coded into 4 bits, in the order of document length in a table format.

As shown in Figure 3, this table is
A table and a table B are prepared, and one of them is selected according to the identification result of the width sensor 13b.

Next, the counter value in this table is compared with the actual counter value detected by the document length detection circuit to obtain the document size code.

This size code is sent to the copying machine main body 16 through the interface 16a, and can be used to determine the magnification of enlargement or reduction and to automatically select copy paper size.

[Effects of the Invention] As explained above, according to the present invention, the length of the document is calculated by counting the number of times the excitation phase of the motor is switched, so it is possible to accurately detect the length of the document. Furthermore, since not only the length of the original but also the width of the original is identified for each original, the original size can be detected correctly even if originals of different sizes are mixed and used.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a control system according to an embodiment of the present invention, FIG. 2 is a circuit diagram of a document length detection circuit of the same embodiment, and FIG.
The figure shows a table of size codes stored in the program memory of the same embodiment, and FIG. 4 is a cross-sectional view of the same embodiment.
FIG. 5 is a sectional view of a conventional example. 13a...Document sensor 13b...Width sensor 24...Brushless motor 32...
・・・・・・Counter 33・・・・・・・・・AND Gate Applicant Toshiba Corporation Agent Patent Attorney Sasa Suyama - Miscellaneous 2 figures Atsushi 3 figures

Claims (2)

[Claims] (1) A conveyance path through which a document is conveyed, a motor driven by switching the excitation phase to convey the document, a counter that counts the switching of the excitation phase of this motor, and a document that passes through the conveyance path. What is claimed is: 1. A document conveying apparatus comprising: a detection means for detecting the passage of the document; and a control means for operating the counter while the passage of the document is detected by the detection means. (2) A patent in which the detection means consists of a first detector installed at a position where it can detect the passage of all originals, and a second detector installed at a position where it can identify the width of the original in the conveyance direction. A document conveying device according to claim 1.