JPH1072129A - Drive control device and control method for rotating body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of an overrun in a document on be half of inertia force of a rotary unit, in the case of stopping each rotary unit for once suspending reading in the half way thereof. SOLUTION: A one-way clutch permitting only one-way rotation is assembled in a receiving roller 36, so as to rotate in the same direction to a rotation permitted direction of the roller 36 by a step motor 22, it is controlled by a CPU. At stopping time, in the CPU, the motor 22 is controlled, the receiving roller 36 is gradually decelerated so as to prevent generation of inertia rotation to stop driving in a stage leading to a rotational speed without generating the inertia rotation. In this way, a document is prevented from overrunning from an expected stop position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to control of driving of a rotating body which is driven and rotated, such as a separation roller for transporting a cut-sheet read original in a facsimile apparatus, or a scanning body in a flat-scanning reading apparatus. The present invention relates to an apparatus and a method for controlling the driving of a rotary driving body including a pulley for driving a motor.

[0002]

2. Description of the Related Art For example, in a document feeding mechanism in a facsimile apparatus, cut-sheet-shaped documents are set on a tray, transported one by one in the direction of a reading mechanism, and read by a CCD (charge coupled device) type image sensor. ing. Here, the original is transported as follows.

[0006] As shown in FIG. 6, the revolving roller 71 is driven to feed the uppermost document A to the downstream side. A transfer roller 7 for transferring the document A is provided downstream of the retraction roller 71.
2 are provided. The retraction roller 71 and the transfer roller 72 are driven by a step motor 73. The rotation speed of the transfer roller 72 is set to a speed slightly higher than that of the retraction roller 71. Therefore, when the document A transported in the transport path reaches the transport roller 72, the document A is drawn to the downstream side by the transport roller 72 due to the speed difference. As a result, there is a difference in the transport speed between the previous document A and the next document A sent out by the rewind roller 71, so that a gap is formed between the next document A. The formation of the gap makes it possible to detect the trailing edge of the document A being transported, so that the size and number of documents to be read can be determined.
Here, in order to allow the document A to be attracted when the document A is attracted by the transport roller 72, the retraction roller 71 is provided with a one-way clutch 74 so as to be able to run idle against rotation in the forward direction.

In some cases, the facsimile apparatus must temporarily stop reading during reading. For example, an image transmission method in a facsimile apparatus includes a real-time image transmission method for transmitting data to a partner machine in real time without temporarily storing data in a memory. In this real-time image transmission method, if the other machine is also printing in real time, it is not possible to cope with this data transmission speed, and it is necessary to stop each roller to temporarily stop reading during reading.

[0005]

However, since the one-way clutch 74 is incorporated in the retraction roller 71 as described above, if the roller 71 is suddenly stopped in order to stop reading, the inertia force of the roller 71 will be applied. There was a risk that the vehicle would idle in the forward direction. Then, there is a possibility that the original A overruns from the original position at the time of the stop, which may hinder the reading when the reading is resumed. Further, when the step motor 73 is suddenly stopped, the impact may cause a problem in peripheral devices. Overrun occurs even when the one-way clutch 75 is not incorporated when the rotating body has a large mass and a high rotating speed, and the same problem occurs.

The present invention has been made by paying attention to such problems existing in the prior art. An object of the present invention is to prevent the document from being overrun due to the inertial force of the rotating body when each rotating body is stopped in order to temporarily stop reading during the reading.

[0007]

Means for Solving the Problems In order to achieve the above object, according to the first aspect of the present invention, a rotating body, a driving means for driving the rotating body, a control means for controlling the driving means, The control means controls the driving means to gradually reduce the rotating body so that inertial rotation does not occur, and stops the driving at a stage when the rotational speed reaches a speed at which inertial rotation does not occur. Make a summary. Thus, when the rotating body in the rotating state stops, the control means controls the driving means to gradually reduce the rotating body so as not to cause inertial rotation. When the rotational speed is reduced to a rotational speed at which inertial rotation does not occur, the drive is stopped at that stage.

According to the second aspect of the present invention, the rotating body having the one-way clutch which permits rotation in only one direction is rotated in the same direction as the rotation allowing direction of the rotating body, and the driving of the rotating body is stopped. The gist of the control is to gradually reduce the speed so that the inertial rotation does not occur, and to stop the rotating body at a stage when the rotational speed reaches a speed at which the inertial rotation does not occur. Thus, when the rotating body in the rotating state stops, the rotating body incorporating the one-way clutch is gradually decelerated so that inertial rotation due to idling of the rotating body does not occur. When the rotational speed is reduced to a rotational speed at which inertial rotation does not occur, the drive is stopped at that stage.

According to the third aspect of the present invention, the rotating body, a one-way clutch which allows the rotating body to rotate only in one direction, and the same rotating body driven in the same direction as the rotation allowing direction of the rotating body. And a control means for controlling the driving means. The control means controls the driving means to gradually reduce the rotating body so that inertial rotation does not occur, and a rotational speed at which inertial rotation does not occur. The gist is that the drive is stopped at the stage when the condition has been reached. As a result, when the rotating body in the rotating state stops, the control means controls the driving means to gradually reduce the speed of the rotating body in which the one-way clutch is incorporated so that inertial rotation due to idling of the rotating body does not occur. When the rotational speed is reduced to a rotational speed at which inertial rotation does not occur, the drive is stopped at that stage.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in an image reading apparatus will be described below with reference to FIGS.
As shown in FIGS. 1, 2, and 4, the image reading apparatus according to the present embodiment includes a device case 11 having a reading mechanism O built therein, a holding lid 12 disposed above the device case 11, and a holding plate 12. And a document transfer section 13 formed at the front (left side in FIG. 1). A cover glass 14 as a transparent support plate on which an original such as a book is placed is attached to the upper opening of the device case 11. On the upper surface of the apparatus case 11, a pressing lid 12 for pressing the original A placed on the cover glass 14 from above is rotatably mounted. The holding lid 12 includes a paper feed tray 15 on which a document A in the form of cut paper before reading is placed. A discharge tray 16 is formed below the paper feed tray 15. A reading window 17 for reading a document A made of transparent glass is attached to the upper surface of the apparatus case 11 and the lower surface of the document transport unit 13.

In the apparatus case 11, a first pulley 18 is provided.
a, 19a and the second pulleys 18b, 19b are rotatably supported. The diameter of the first pulleys 18a, 19a is twice the diameter of the second pulleys 18b, 19b. First
A first belt 20 is hung between the pulleys 18a and 19a of the pulley, and rotates integrally on the same axis. Second pulley 18b, 1
A second belt 21 is hung between 9b and rotates integrally on the same axis.

A stepping motor 22 as a driving device according to the present invention is disposed in front of the inside of the device case 11.
The rotation of the step motor 22 is transmitted to one of the pulleys 18a and 18b via a plurality of gears (not shown). Therefore, when the step motor 22 is driven, both belts 2 are driven via the same gear and pulleys 18a, 19a, 18b, 19b.
0 and 21 are circulated clockwise or counterclockwise. In each pulley 18a, 19a, 18b, 19b, the first
Of the pulleys 18a, 19a of the second pulley 18b,
Since the diameter of the belt 19 is twice as large, the circling speed of the first belt 20 is twice that of the second belt 21.

The first moving frame 23 is a device case 11
The belts 20 and 21 are arranged so as to be able to reciprocate along the extending direction thereof. The first moving frame 22 is the first
Of the belt 20. The light source 25 and the first mirror 26 are attached to the first moving frame 22,
It extends along a direction perpendicular to the plane of the paper. The light source 25 is
The document placed on the cover glass 14 is irradiated with light through the cover glass 14. First mirror 26
Reflects the vertically reflected light coming from the document in the horizontal direction.

The second moving frame 24 is mounted on the device case 11.
The belts 20 and 21 are arranged so as to be able to reciprocate along the extending direction thereof. The second moving frame 24 is
Of the belt 21. Second moving frame 2
4 is provided with second and third mirrors 27 and 28, which extend along a direction perpendicular to the plane of the drawing. The second mirror 27 reflects the reflected light in the horizontal direction incident from the first mirror 26 in the vertical direction. Third mirror 2
Numeral 8 reflects the vertically reflected light incident from the second mirror 27 in the horizontal direction.

Lens 31 and CCD image sensor 3
2 is fixedly disposed in the device case 11 via a fixing frame 43. The reflected light in the horizontal direction from the third mirror 28 is transmitted through a lens 31 to an image sensor 32.
, The image on the document is read by the image sensor 32. The reading mechanism O includes the light source 25, the first to third mirrors 26, 27, 28, the lens 31 and the CCD image sensor 32.

In such a configuration, the cover glass 1
When reading an original such as a book on 4 (book reading),
Both moving frames 23 and 24 are scanned during a predetermined stroke in the horizontal direction in FIG. Here, since the revolving speed of the second belt 21 is 倍 times the revolving speed of the first belt 20, when the first moving frame 23 is moved in one direction at a predetermined speed, the second moving speed is increased. Moving frame 24
Are moved in the same direction at half the speed. Since the moving speed of the first moving frame 23 is twice the moving speed of the second moving frame 24, both moving frames 2
Even if 3 and 24 are moved, the image sensor 3
The length of the optical path leading to 2 is always constant. Therefore, the original A
Is always constant with respect to the image sensor 32.

As shown in FIG. 2, an end sensor 33 composed of a microswitch is disposed near a boundary between the pressing plate 12 and the document transport section 13 in the apparatus case 11.
When the end sensor 33 detects the passage of the second moving frame 24, a predetermined time elapses (step motor 22).
The first and second moving frames 23 and 24 are moved to the automatic reading position Q shown in FIG.

Next, the document transfer section 13 for automatically reading the document A will be described. As shown in FIGS. 1 and 2, the uppermost original A on the paper feed tray 15 is
Rollers 36 for feeding the paper into the document transport section 13
, 38, 40-43, a belt 39, a transfer path R, and the like. In the vicinity of the document insertion port 34, the retraction roller 36 and the retraction roller 3
7 are provided. The rollers 36 and 37 are connected to the motor 22 via a gear mechanism (not shown), and the drive of the motor 22 is transmitted. Roll-in roller 36 is original A
In the clockwise direction as shown in the figure. As shown in FIG. 2, a one-way clutch 35 that allows the rotation of the retraction roller 36 in the retraction direction (clockwise direction in the drawing) is incorporated between the retraction roller 36 and its shaft 36 a. The retraction roller 36 rotates integrally with the shaft 36a, and allows the roller 36 to rotate at a higher speed than the shaft 36a. The rewinding roller 37 rotates clockwise in the figure to prevent the reversal of the original A other than the uppermost original A.

The side of the rewinding roller 36 (paper feed tray 1
On the (5th side), a paper feed auxiliary roller 38 is provided. The paper feed auxiliary roller 38 is supported by a lever 39,
The drive of the running-in roller 36 is transmitted by a belt (not shown). The paper feed auxiliary roller 38 is a retraction roller 36
, And descends by the transmission force of the belt, abuts on the upper surface of the uppermost document A to assist paper feeding.

A transfer roller 40 is provided downstream of the retraction roller 36. The transfer roller 40 is connected to the motor 22 via a gear mechanism (not shown), and the drive of the motor 22 is transmitted. The transfer roller 40 is set at a speed slightly higher than the rotation speed of the retraction roller 36.
Therefore, when the document A transported in the transport path R reaches the transport roller 40, the document A is drawn to the downstream side by the transport roller 40 due to the speed difference between the two rollers 36, 40. As a result, there is a difference in transport speed between the previous document A and the next document A sent out by the feeding roller 71, so that a gap is formed between the document A and the next document A. For this reason, the passage sensor 45 can detect the rear end of the document A being transported.

In the automatic reading mode, the two paper feed rollers 3
The document A sent into the document transporting unit 13 by the documents 6 and 37 is transported while being sandwiched between the transport roller 40 and the pair of driven rollers 41, is reversed, and passes through the reading window 17. The document A, which has been read through the reading window 17 by the reading mechanism O at the automatic reading position Q, is discharged from the document discharge port 44 to the discharge tray 1 by a pair of discharge rollers 42, 43.
6 is discharged. The upper discharge roller 42 is connected to the motor 22 via a gear mechanism (not shown), and the drive of the motor 22 is transmitted.

Next, the electrical configuration of the image reading apparatus will be described with reference to FIG. A CPU (Central Processing Unit) 51 is connected to a ROM (Read Only Memory) 52 that stores a program for controlling the operation of the entire apparatus and a RAM (Random Access Memory) 53 that temporarily stores various information. ing. CPU 51, ROM 52, and RAM 5
Reference numeral 3 constitutes control means. Further, the step motor 22 is connected to the CPU 51 via a drive circuit 54, and the end sensor 33 and the passage sensor 45 are connected to the CPU 51.
Is connected. The drive circuit 54 generates an excitation signal based on a drive pulse of a predetermined frequency output from the CPU 51 and supplies the excitation signal to the step motor 22. The step motor 22 is driven to rotate one step at a time by an excitation signal from the drive circuit 54.

The encoding circuit 56 encodes the image data read by the reading mechanism O. An NCU (network control unit) 57 controls a line connection with an external facsimile apparatus F or a telephone line L connected to the image reading apparatus. The modem 58 modulates transmission data. The operation key group 59 includes a scanner communication key 60,
Various keys such as a copy key 61 and a reading start key 62 are provided.

The CPU 51 sets the scanner communication mode when the scanner communication key 60 is on, and in the mode, the image data on the document A read by the reading section 55 is transmitted to the partner machine via the telephone line L under the mode. Send. On the other hand, when the copy key 61 is on, the CPU 51 sets the copy mode, and causes the printer (not shown) to copy and output the read image data. That is, the image reading apparatus of the present embodiment has a facsimile transmission function and a copy function. The selection of the scanner communication mode or the copy mode is performed alternatively. The display unit 63 includes a liquid crystal display panel or an LED, and displays a current state of the image reading apparatus such as “scanner communication mode”, “copy mode”, “standby”, and “device abnormality”.

In the image reading apparatus having such a configuration,
A drive control method of the retraction roller 37 will be described.
FIG. 5 is a graph showing the relationship between the rotation speed of the retraction roller 37 and time when the stepping motor 22 is rotationally controlled by the CPU 51. The vertical axis represents the rotation speed r of the retraction roller 37, and the horizontal axis represents time t. On the graph, a thick line L1 indicates a change in the rotation speed of the retraction roller 37 over time. The straight line descending to the right represented by the one-dot chain line L0 is a negative constant acceleration straight line, and if the retraction roller 37 is decelerated at a higher speed, inertial rotation occurs (the one-way clutch 3 of the retraction roller 37).
5, the revolving roller 37 idles with respect to the drive shaft 36a). Also, the roller speed r1
Is a speed at which inertial rotation does not occur in the retraction roller 37 even when the step motor 22 is stopped instantaneously.

It is now assumed that the reading of the document A is being executed in the automatic reading mode from time t0 to t1. That is,
Under the control of the CPU 51, the stepping motor 22 performs a constant driving based on a driving pulse of a predetermined frequency.
The roller 36 is rotating at a constant speed r0.

If no image data request signal is input from the partner machine at time t1, reading of the document A must be temporarily stopped. The CPU 51 controls the step motor 22 to stop the retraction roller 36 from time t1 to t3 so that inertial rotation does not occur. First, C
PU51 is the rewinding roller 3 from time t1 to t2.
The step motor 22 is controlled so as to reduce the speed 6 to the speed r1 by negative equal acceleration. That is, the running-in roller 36 reaches the speed r1 at time t2 while decelerating at a constant rate. Here, on the graph, the angle θ2 corresponding to the deceleration of the retraction roller 36 must be set to θ2> θ1. If θ2 is smaller than θ1, inertia rotation of the retraction roller 36 occurs. If the retraction roller 36 is reduced to this speed r1, inertial rotation no longer occurs. Thereafter, when the speed r1 is maintained and the time t3 is reached, the operation is stopped at a stretch. The above control conditions of the CPU 51 are determined by various conditions such as the weight of the roller 37 and the reading speed of the document A.

The image reading apparatus of this embodiment has the following effects. (1) When stopping the running-in roller 36, instead of stopping immediately, the running-in roller 36 is gradually decelerated so that inertial rotation does not occur, and further stopped at a stage where the speed is such that inertial rotation does not occur. I made it. Therefore, there is no possibility that inertial rotation occurs in the rewinding roller 36.
As a result, the document A can be stopped at a predetermined position without overrunning, so that there is no problem in subsequent reading.

(2) The rewinding roller 36 is gradually decelerated to a low speed at which inertial rotation does not occur, and then stopped.
The peripheral device of No. 6 is unlikely to cause a problem due to an impact. Also,
Inconveniences due to the impact hardly occur in peripheral devices of the step motor 22.

(3) In the above embodiment, after the retraction roller 36 is reduced to a speed r1 at which inertial rotation does not occur,
When the speed r1 was maintained and the time t3 was reached, the operation was stopped at once. Therefore, once the speed r1 is reached, even if the retraction roller 36 is immediately stopped at a desired position, inertial rotation does not occur and the roller 36 can be stopped exactly at that position.
It should be noted that the same effect can be obtained by stopping the motor at a desired time after the speed r1 has been reached.

The present invention can be embodied with the following modifications. (1) In the above embodiment, the revolving roller 36 in which the one-way clutch 35 is incorporated is controlled. However, if the rotating body has a large mass without the one-way clutch 35, inertial rotation occurs and overrun occurs. Sometimes. For example, the other rollers 37 and 4 that are driven and transmitted from the step motor 22 in the above embodiment.
Stop control may be performed using the pulleys 18a and 18b for moving the moving frames 23 and 24 as rotating bodies.

For example, if the moving frames 23 and 24 stop suddenly, an overrun occurs, and the reading device O installed on these moving frames 23 and 24 cannot stop at a regular position. Where it is necessary for the reading device O to be stopped at a regular position for accurate reading,
By controlling the rotation of the pulleys 18a and 18b, overrun can be prevented. The control of these rollers 37, 40, 42 and the pulleys 18a, 18b may be performed in combination with the control of the above embodiment, or may be performed alone.

(2) In the above-described embodiment, the revolving roller 36 maintains the speed t1 until the speed r1 at which the inertial rotation does not occur. However, it is not always necessary to control in this way. If the speed r1 at which rotation does not occur is reached, it may be stopped immediately.

(3) In the above embodiment, as shown in the graph of FIG. 5, the speed r1 of the rewinding roller 36 from the time t1 to the time t2 is decelerated by negative equal acceleration. However, in this case, it is only necessary to exceed the limit value at which the inertial rotation occurs, and it is not always necessary to decelerate with equal acceleration.

(4) In the above embodiment, an image reading apparatus such as a facsimile having a copying function is embodied. However, an image recording apparatus such as a copying machine or a printer may be used. In addition, the present invention can be freely implemented without departing from the gist of the present invention.

The technical ideas that can be grasped from the above embodiment will be described below. (1) The control means controls to gradually reduce the rotational speed to a rotational speed at which inertial rotation does not occur, and to rotate the rotary body at a constant speed before stopping the rotary body when the rotational speed is reached. The drive control device for a rotating body according to claim 1.

(2) A rotating body having a one-way clutch that allows rotation in only one direction is rotated in the same direction as the rotation allowing direction of the rotating body, and rotation in which inertial rotation does not occur when the rotating body is stopped. A drive control method for a rotating body in which the rotating body is gradually decelerated to a speed, and at the stage when the rotating speed is reached, the rotating body is rotated at a constant speed, and then the rotating body is stopped.

(3) The roller drive control device according to any one of (1) to (3) or (1), wherein the rotating body is a roller. (4) The drive control method for a roller according to claim 2, wherein the rotating body is a roller.

(5) The sheet feed roller drive control device according to (3), wherein the roller is a rewinding roller for rewinding a document read by an image reading device or an image recording device.
(6) The driving control method of the sheet feed roller according to the above (4), wherein the roller is a rewinding roller for rewinding a document read by an image reading device or an image recording device.

[0040]

As described above in detail, according to the first aspect of the present invention, when the rotating body is stopped, the rotating body is not stopped immediately but gradually so that inertial rotation does not occur in the rotating body. The vehicle is decelerated and stopped at a stage where the inertia rotation does not occur. Therefore, there is no risk of inertial rotation of the rotating body, and there is no impact due to sudden stop. According to the second and third aspects of the present invention, even if the one-way clutch facilitates the inertial rotation of the rotating body, the rotating body is gradually decelerated so that the inertial rotation does not occur, and further the inertial rotation does not occur. Stop when the speed is reached. For this reason, there is no risk of inertial rotation of the rotating body, and there is no impact due to sudden stop.

[Brief description of the drawings]

FIG. 1 is a sectional view of an image reading apparatus according to an embodiment of the present invention.

FIG. 2 is a partially enlarged cross-sectional view of the image reading device.

FIG. 3 is a block diagram of the image reading apparatus.

FIG. 4 is a side view of the image reading apparatus.

FIG. 5 is a graph showing the relationship between the rotation speed of the retraction roller and time.

FIG. 6 is a schematic explanatory view of a conventional document supply mechanism.

[Explanation of symbols]

22 ... Recessed step motor as driving means, 33
.., A revolving roller as a rotating body, 35, a one-way clutch, 51, a CPU as control means.

Claims (3)

[Claims] 1. A rotating body, a driving means for driving the rotating body, and a control means for controlling the driving means, wherein the controlling means controls the driving means to rotate so that inertial rotation does not occur. A drive control device for a rotating body that gradually decelerates the body and stops driving at a rotational speed at which inertial rotation does not occur. 2. A rotating body having a one-way clutch that allows rotation in only one direction is rotated in the same direction as the rotation allowing direction of the rotating body, and no inertial rotation occurs in the drive stop control of the rotating body. A drive control method for a rotating body in which the rotating body is gradually decelerated as described above and stopped at a rotation speed at which inertial rotation does not occur. 3. A rotating body, a one-way clutch that allows the rotating body to rotate only in one direction, a driving unit that drives the rotating body in the same direction as the rotation allowable direction of the rotating body, and a driving unit that includes: Control means for controlling the drive means to gradually decelerate the rotating body so that inertial rotation does not occur, and stop driving when the rotational speed reaches a speed at which inertial rotation does not occur. Drive control device for the rotating body.