JPH09233876A - Image scanner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image scanner which can control a first travelling body where an optical system is mounted to a target speed with high accuracy. SOLUTION: The speed v(i-1) of a motor 18 is detected by an encoder and then is input into a multiplying section 32. In the multiplying section 32, the motor speed v(i-1) is multiplied by a speed correction coefficient Vcorrec and the result is returned to an operational section 34. The operational section 34 calculates a difference e(i) between the input control target value R(i) and the signal from the multiplying section 32 and then the difference e(i) is integrated in an integrating section 35. In a multiplying section 36, the integrated value is multiplied by a constant Ki and the result is output to an operational section 37. Meanwhile, the operational section 34 outputs the difference e(i) to a multiplying section 38. in the multiplying section 38, the difference e(i) is multiplied by a constant Kp and the result is output to the operational section 37. The operational section 37 adds up the inputs from the multiplying sections 36, 38 and outputs the result to the motor 18 as a control voltage u(i). By this method, the speed at which the ratio of a mean value Vmean of the first traveling body to a target value Vref is fed back as the correction coefficient Vcorrec can be corrected and thereby the control can be made with no deviation in speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image reading device, and more particularly to an image reading device for accurately speed-controlling a traveling body equipped with an optical system.

[0002]

2. Description of the Related Art In an image reading apparatus such as a scanner apparatus, a facsimile apparatus and a copying apparatus, an original reading apparatus that reads a stationary image by moving an optical system is often applied.

Conventionally, such a document reading apparatus includes a first traveling body and a second traveling body which are movably guided in the sub-scanning direction, and the first traveling body projects a light source and a document from a light source onto the first traveling body. A first mirror for introducing reflected light of the reflected light to the second traveling body is mounted. The second traveling body has a second mirror and a third mirror mounted thereon, and the second mirror introduces light from the first mirror of the first traveling body to the third mirror. The third mirror is
The light from the second mirror is introduced into a photoelectric conversion unit, for example, a CCD (Charge Coupled Device) through a lens, and the incident light is converted into an electric signal by the photoelectric conversion unit to read an image of a document.

In such a document reading apparatus, in the standby state, the first traveling body and the second traveling body are located at the home position, and when the document is read, the first traveling body and the second traveling body are moved to the original position. When the document is moved forward in the sub-scanning direction, the original is irradiated with light from the light source mounted on the first traveling body, and the reflected light reflected by the original is received by the first mirror of the first traveling body, 2 Project on the second mirror of the traveling body. The second mirror reflects the incident light to the third mirror, and the third mirror irradiates the photoelectric conversion means through the lens, photoelectrically converts the incident light by the photoelectric conversion means, and reads the image of the document. And
When the reading of the image for one page is completed, the first traveling body and the second traveling body are moved back to the home position,
Prepare to read the next document.

In such an image reading apparatus that reads the image of the original by moving the running body, it is important to properly control the speed of the running body in order to read the image accurately.

[0006] Therefore, the applicant of the present invention, when the traveling body is moved forward, the rise up to a constant speed is different due to the difference in the forward movement start position and the variation in the individual mechanical load of the image reading apparatus. Also proposes a control method of a scanner optical system that can perform acceleration control of the first traveling body and the second traveling body smoothly by making the gain variable, and can perform a stable reading operation (special feature. Kaihei 6-1101
No. 37). The control method of this scanner optical system is
A scanner optical system capable of reciprocating operation, a scanner carrying motor for carrying the scanner optical system, a moving speed detecting means for detecting a moving speed of the scanner optical system, and a moving distance of the scanner optical system A moving distance detecting means for detecting, and a result obtained by the moving speed detecting means and the distance detecting means so as to stabilize at a predetermined scan speed up to a predetermined position when the scanner optical system moves forward. Of the document leading edge detected by the moving distance detection means in a series of scanner optical system forward movement control in which the acceleration control is performed by feedback control to the power applied to the motor, and the control is performed to move at a constant speed when the reference position is reached. Read the maximum scanner speed of the scanner up to a certain point before the position or the front of the document and read it according to the scan speed. Te, as an acceleration control value at the time of the next forward scan, performs feedback control, is characterized in that the gain of the feedback control system during acceleration is made variable.

That is, the above-described method for controlling the scanner optical system reads the position information or time when the speed of the scanner and the target speed in the image reading section exceed or fall below a certain value, and read the position information or time information. According to the above, feedback control is performed as a control value at a constant speed in the next forward scan, and the gain of the feedback control system at a constant speed is made variable. According to this scanner optical system control method, when performing speed control of the forward movement of the scanner optical system, speed fluctuations occur within a range (constant speed range) in which it is necessary to maintain a constant speed due to fluctuations in sliding load. However, since the gain is corrected in the next scan, the speed of the scanner optical system can be kept constant, and an image without stretching or vibration can be read.

[0008]

However, in the method described in the above-mentioned Japanese Patent Application Laid-Open No. 6-110137, the position information when the scanner speed and the target speed exceed or fall below a certain value, or Since the time information is read and the feedback control is performed as the control value at the constant speed in the next forward scan, the gain of the feedback control system at the constant speed can be made variable, so that the response operation of the scanner optical system can be changed. The speed fluctuation during speed control can be suppressed within a certain range, but the speed deviation caused by the steady frictional force accompanying the movement of the first traveling body and the second traveling body and the error of the control system, that is, the image reading The magnification error of the device cannot be removed, and there is still room for improvement in improving the read image.

Therefore, in the invention according to claim 1, when the moving speed of the first traveling body is detected and this moving speed is fed back, the moving speed of the first traveling body is feedback-controlled to the target speed in advance. The average traveling speed of one traveling body is obtained, and the traveling speed that is fed back as a correction coefficient is calculated by the ratio of the average traveling speed to the target traveling speed of the first traveling body. It is an object of the present invention to provide an image reading apparatus that does not cause an error.

According to a second aspect of the present invention, when the moving speed of the first traveling body is detected, the moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to the target speed, the first traveling is performed in advance. The average moving speed of the body is calculated, and the target speed is corrected by using the ratio of the average moving speed and the target speed of the first traveling body as a correction coefficient, so that control without speed deviation is performed and no magnification error occurs. An object is to provide an image reading device.

According to the third aspect of the present invention, when the moving speed of the first traveling body is detected and the moving speed is fed back to feedback control the moving speed of the first traveling body to the target speed, the sub-scanning direction is previously set. Of the average traveling speed of the first traveling body in a plurality of reading sizes, the ratio of the average traveling speed to the target traveling speed of the first traveling body is stored as a table, and the traveling speed correction coefficient to be fed back based on the table is stored. Therefore, it is an object of the present invention to provide an image reading apparatus that does not cause a magnification error by performing control without speed deviation for various reading sizes.

According to a fourth aspect of the present invention, when the moving speed of the first traveling body is detected and the moving speed is fed back to feedback control the moving speed of the first traveling body to the target speed, the sub-scanning direction is previously set. The average moving speed of the first traveling body is obtained in a plurality of reading sizes, the ratio of the average traveling speed to the target speed of the first traveling body is stored as a table, and the correction coefficient of the target speed is obtained based on the table. Accordingly, it is an object of the present invention to provide an image reading apparatus that does not cause a magnification error by performing control without speed deviation for various reading sizes.

According to a fifth aspect of the present invention, when the moving speed of the first traveling body is detected, the moving speed is fed back, and the traveling speed of the first traveling body is feedback-controlled to the target speed, a plurality of reading sizes are read. As a method of obtaining the correction coefficient of the moving speed to be fed back in, by combining the method of obtaining the correction coefficient in advance and setting it in the table and the method of obtaining it at the time of pre-scan, it is possible to more practically read the correction of the moving speed to be fed back. An object is to provide an image reading device applicable to size.

According to a sixth aspect of the present invention, the moving speed of the first traveling body is detected, the moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to the target speed. As a method of obtaining the correction coefficient of the target speed in the above, by combining the method of obtaining the correction coefficient in advance and making a table and the method of obtaining it at the time of pre-scan, the correction of the target speed is more practically applied to all reading sizes It is an object of the present invention to provide an image reading device capable of performing the above.

According to a seventh aspect of the present invention, the image reading apparatus capable of correcting the moving speed and the target speed for more practical feedback by storing the correction coefficient in the table only for the read size of the specified size. Is intended to provide.

According to an eighth aspect of the present invention, the moving speed of the first traveling body is detected, the moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to the target speed. First according to size
The average moving speed of the running body is calculated, and the average moving speed and the first
By correcting the moving speed to be fed back by using the ratio to the target speed of the traveling body as a correction coefficient, it is possible to always accurately correct the speed deviation even if the image reading apparatus changes with time. Is intended to provide.

According to a ninth aspect of the present invention, the moving speed of the first traveling body is detected, the moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to the target speed. First according to size
The average moving speed of the running body is calculated, and the average moving speed and the first
Provided is an image reading device capable of always correcting an accurate speed deviation even if a change with time occurs in the image reading device by correcting the target speed by using a ratio with a target speed of a traveling body as a correction coefficient. The purpose is to do.

[0018]

According to another aspect of the present invention, there is provided an image reading apparatus including: a light source for irradiating a document with light; and an optical system for introducing light reflected by the document into a photoelectric conversion element as a first traveling body. The second traveling body is separately mounted, and when the first traveling body is moved in the sub-scanning direction by the driving means, the second traveling body is driven at a speed ratio of 2: 1 with respect to the first traveling body to perform sub-scanning. While moving in the direction, the image of the original is read, the moving speed of the first traveling body is detected by the moving speed detecting means, the detected moving speed is fed back, and the moving speed of the first traveling body is set to a predetermined value. In an image reading device that performs feedback control to a target speed, based on the detection result of the moving speed detection means,
An average moving speed of the first traveling body is calculated in advance, and the moving speed of the first traveling body to be fed back is multiplied by using a ratio of the average traveling speed and the target speed of the first traveling body as a correction coefficient. By doing so, the moving speed to be fed back is corrected, and the above object is achieved.

Here, the first traveling body is equipped with, for example, a light source and a mirror for receiving the reflected light of the light emitted from the light source to the original and reflecting it toward the second traveling body. Is equipped with, for example, a second mirror and a third mirror,
The mirror reflects the light from the first mirror of the first traveling body to the third mirror, and the third mirror reflects the light from the second mirror to the photoelectric conversion element.

The first traveling body is moved in the sub-scanning direction by the driving means, and the second traveling body is driven by the movement of the first traveling body to have a speed ratio of 2: 1 with respect to the first traveling body. Move in the sub-scanning direction. The moving speed of the first traveling body is detected by a moving speed detecting means, for example, an encoder or the like, is fed back, and is feedback-controlled to a predetermined target speed.

Based on the detection result of the moving speed detecting means,
The average moving speed of the first traveling body is calculated in advance, the ratio between the average moving speed and the target speed of the first traveling body is calculated, and the calculated coefficient is stored in a memory or the like as a correction coefficient. This correction coefficient is multiplied by the moving speed of the first traveling body detected by the moving speed detecting means to be fed back for feedback control, and the moving speed to be fed back is corrected.

According to the above configuration, when the moving speed of the first traveling body is detected, the moving speed is fed back, and when the moving speed of the first traveling body is feedback-controlled to the target speed, the traveling speed of the first traveling body is previously controlled. Since the average moving speed is obtained and the moving speed to be fed back is corrected by using the ratio of the average moving speed and the target speed of the first traveling body as the correction coefficient,
Speed control without speed deviation can be performed, and an image without magnification error can be read.

In the image reading apparatus of the second aspect of the present invention, the light source for irradiating the original with light and the optical system for introducing the light reflected by the original into the photoelectric conversion element are divided into the first traveling body and the second traveling body. When the first traveling body is moved in the sub-scanning direction by the driving means, the second traveling body is driven at a speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction. The image of the original is read, the moving speed of the first traveling body is detected by the moving speed detecting means, the detected moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to a predetermined target speed. In the image reading device, an average moving speed of the first traveling body is calculated in advance based on a detection result of the moving speed detecting means, and a ratio between the average traveling speed and the target speed of the first traveling body is corrected. As a coefficient, the By multiplying the target speed, by correcting the target speed, it has achieved the above objects.

Here, the moving speed detected by the moving speed detecting means is fed back to feedback control the moving speed of the first traveling body to the target speed. The ratio of the average moving side to the degree target speed is set to this target speed. The target speed is corrected by multiplying the target speed by using as a correction coefficient.

According to the above configuration, when the moving speed of the first traveling body is detected, the moving speed is fed back, and when the moving speed of the first traveling body is feedback-controlled to the target speed, the traveling speed of the first traveling body is previously controlled. Since the average speed is calculated and the target speed is corrected using the ratio of the average speed and the target speed of the first traveling body as a correction coefficient, speed control without speed deviation can be performed, and the magnification error It is possible to read an image that does not occur.

In the image reading apparatus of the third aspect of the present invention, the light source for irradiating the original with light and the optical system for introducing the light reflected by the original into the photoelectric conversion element are divided into the first traveling body and the second traveling body. When the first traveling body is moved in the sub-scanning direction by the driving means, the second traveling body is driven at a speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction. The image of the original is read, the moving speed of the first traveling body is detected by the moving speed detecting means, the detected moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to a predetermined target speed. In the image reading device, an average moving speed of the first traveling body in a plurality of reading sizes in the sub-scanning direction is calculated in advance based on a detection result of the moving speed detecting unit, and an average moving speed of the plurality of reading sizes is calculated. In front of the first traveling body By storing a ratio with a target speed as a correction coefficient table, reading a correction coefficient corresponding to the size of the document to be read from the correction coefficient table, and multiplying by the moving speed of the first traveling body to be fed back, The moving speed to be fed back is corrected to achieve the above object.

Here, the correction coefficient table is stored in a memory or the like, and the correction coefficients for a plurality of reading sizes in the sub-scanning direction are stored.

When the reading size is designated or detected at the time of reading the original, the correction coefficient corresponding to the reading size is determined, read from the correction coefficient table, and fed back by the read correction coefficient. Correct the moving speed of.

According to the above configuration, when the moving speed of the first traveling body is detected and the moving speed is fed back to feedback control the traveling speed of the first traveling body to the target speed, a plurality of sub-scanning directions are previously set. The average moving speed of the first traveling body in the reading size is calculated, the ratio of the average moving speed to the target speed of the first traveling body is stored as a table, and when reading the document, the table is stored according to the reading size of the document. It is possible to correct the moving speed to be fed back by determining the correction coefficient from the above and multiplying the moving speed to be fed back by the determined correction coefficient. As a result, it is possible to perform control without speed deviation for various reading sizes, and it is possible to read an image with no magnification error.

In the image reading apparatus according to the present invention, the light source for irradiating the original and the optical system for introducing the light reflected by the original into the photoelectric conversion element are divided into the first traveling body and the second traveling body. When the first traveling body is moved in the sub-scanning direction by the driving means, the second traveling body is driven at a speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction. The image of the original is read, the moving speed of the first traveling body is detected by the moving speed detecting means, the detected moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to a predetermined target speed. In the image reading device, an average moving speed of the first traveling body in a plurality of reading sizes in the sub-scanning direction is calculated in advance based on a detection result of the moving speed detecting unit, and an average moving speed of the plurality of reading sizes is calculated. In front of the first traveling body By storing the ratio with the target speed as a correction coefficient table, reading the correction coefficient corresponding to the size of the document to be read from the correction coefficient table, and multiplying the target speed of the first traveling body by the target speed. To achieve the above objective.

According to the above construction, when the moving speed of the first traveling body is detected and the moving speed is fed back to control the moving speed of the first traveling body to the target speed by feedback control, a plurality of sub-scanning directions are previously set. The average moving speed of the first traveling body in the reading size is calculated, the ratio of the average moving speed to the target speed of the first traveling body is stored as a table, and when reading the document, the table is stored according to the reading size of the document. It is possible to correct the target speed by determining the correction coefficient from the above and multiplying the target speed by the determined correction coefficient. As a result, it is possible to perform control without speed deviation for various reading sizes, and it is possible to read an image with no magnification error.

In the image reading apparatus according to the fifth aspect of the present invention, the light source for irradiating the original with light and the optical system for introducing the light reflected by the original into the photoelectric conversion element are divided into the first traveling body and the second traveling body. When the first traveling body is moved in the sub-scanning direction by the driving means, the second traveling body is driven at a speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction. The image of the original is read, the moving speed of the first traveling body is detected by the moving speed detecting means, the detected moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to a predetermined target speed. In the image reading device, an average moving speed of the first traveling body in a plurality of reading sizes in the sub-scanning direction is calculated in advance based on a detection result of the moving speed detecting unit, and an average moving speed of the plurality of reading sizes is calculated. In front of the first traveling body The ratio to the target speed is stored as a correction coefficient table, and when the correction coefficient is stored in the correction coefficient table corresponding to the size of the document to be read, the correction coefficient is read and the feedback is performed. The moving speed of the traveling body is multiplied to correct the moving speed to be fed back, and if the correction coefficient is not stored in the correction coefficient table corresponding to the size of the original to be read, the original is prescanned. Then, the average traveling speed of the first traveling body is calculated, the ratio between the average traveling speed and the target speed of the first traveling body is calculated as a correction coefficient, and the feedback is performed for the first traveling body. The moving speed is corrected by multiplying the moving speed to achieve the above object.

Here, in the prescan, the reading range of the original is scanned before reading the original. When the prescan is performed, the first traveling body is detected based on the detection result of the movement detecting means. The average moving speed of is calculated and the correction coefficient is calculated.

According to the above configuration, when the moving speed of the first traveling body is detected and the moving speed is fed back to feedback control the moving speed of the first traveling body to the target speed, the feedback in a plurality of reading sizes is performed. As a method of obtaining the correction coefficient of the moving speed, the method of obtaining the correction coefficient in advance and making a table and the method of obtaining it at the time of pre-scan are used together, so that the correction coefficient corresponding to more various reading sizes is set, The moving speed to be fed back can be corrected, and the moving speed to be fed back can be corrected more practically for any reading size. As a result, it is possible to perform speed control without speed deviation for all reading sizes, and it is possible to read an image with no magnification error.

In the image reading apparatus according to the sixth aspect of the present invention, the light source for irradiating the original with light and the optical system for introducing the light reflected by the original into the photoelectric conversion element are divided into the first traveling body and the second traveling body. When the first traveling body is moved in the sub-scanning direction by the driving means, the second traveling body is driven at a speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction. The image of the original is read, the moving speed of the first traveling body is detected by the moving speed detecting means, the detected moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to a predetermined target speed. In the image reading device, an average moving speed of the first traveling body in a plurality of reading sizes in the sub-scanning direction is calculated in advance based on a detection result of the moving speed detecting unit, and an average moving speed of the plurality of reading sizes is calculated. In front of the first traveling body The ratio to the target speed is stored as a correction coefficient table, and when the correction coefficient is stored in the correction coefficient table corresponding to the size of the document to be read, the correction coefficient is read and the first traveling body The target speed is corrected by multiplying the target speed, and if the correction coefficient is not stored in the correction coefficient table corresponding to the size of the original to be read, the original is pre-scanned and the By calculating an average moving speed of one traveling body, calculating a ratio of the average moving speed and the target speed of the first traveling body as a correction coefficient, and multiplying the target speed of the first traveling body by The target speed is corrected to achieve the above object.

According to the above configuration, when the moving speed of the first traveling body is detected and the moving speed is fed back to feedback control the traveling speed of the first traveling body to the target speed, the target for a plurality of reading sizes can be obtained. As a method of obtaining the correction coefficient of speed, the method of obtaining the correction coefficient in advance and making a table and the method of obtaining it at the time of pre-scan are used together. Therefore, the correction coefficient corresponding to various reading sizes is set and the target speed is set. Can be corrected and the target speed correction can be more practically applied to any reading size. As a result, it is possible to perform speed control without speed deviation for all reading sizes, and it is possible to read an image with no magnification error.

In the case of claims 5 and 6, for example, as described in claim 7, the plurality of read sizes in which the correction coefficient is stored in the correction coefficient table are A3, A4, B4. , B5, etc. may be specified.

According to the above configuration, since the correction coefficient is stored as a table only for the read size of the specified size, it is possible to perform the correction of the moving speed and the target speed for more practical feedback.

In the image reading apparatus of the present invention, the light source for irradiating the original and the optical system for introducing the light reflected by the original into the photoelectric conversion element are divided into the first traveling body and the second traveling body. When the first traveling body is moved in the sub-scanning direction by the driving means, the second traveling body is driven at a speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction. The image of the original is read, the moving speed of the first traveling body is detected by the moving speed detecting means, the detected moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to a predetermined target speed. In the image reading device, at the time of reading the original, the original is pre-scanned over the reading size in advance, the average moving speed of the first traveling body is calculated based on the detection result of the moving speed detecting means, and the average moving is performed. Speed and before By using the ratio of the first traveling body to the target speed as a correction coefficient and multiplying the moving speed of the first traveling body to be fed back, the moving speed to be fed back is corrected to achieve the above object. .

According to the above configuration, when the moving speed of the first traveling body is detected and the moving speed is fed back to feedback control the moving speed of the first traveling body to the target speed, the read size is set at the prescan. The average moving speed of the first traveling body is calculated according to the calculated moving speed, and the moving speed to be fed back is corrected using the ratio of the average moving speed and the target speed of the first traveling body as a correction coefficient. Even if occurs, it is possible to always correct the speed deviation accurately.

In the image reading apparatus according to the present invention, the light source for irradiating the original with light and the optical system for introducing the light reflected by the original into the photoelectric conversion element are divided into the first traveling body and the second traveling body. When the first traveling body is moved in the sub-scanning direction by the driving means, the second traveling body is driven at a speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction. The image of the original is read, the moving speed of the first traveling body is detected by the moving speed detecting means, the detected moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to a predetermined target speed. In the image reading device, at the time of reading the original, the original is pre-scanned over the reading size in advance, the average moving speed of the first traveling body is calculated based on the detection result of the moving speed detecting means, and the average moving is performed. Speed and before The ratio of the target speed of the first carriage as the correction factor, and more multiplied to the target speed of the first carriage, by correcting the target speed, has achieved the above objects.

According to the above construction, when the moving speed of the first traveling body is detected and the moving speed is fed back to feedback control the moving speed of the first traveling body to the target speed, the read size is set at the prescan. The average moving speed of the first traveling body is calculated in accordance with the target traveling speed, and the target speed is corrected using the ratio of the average traveling speed and the target speed of the first traveling body as a correction coefficient. Even if
Accurate correction of speed deviation can always be performed.

[0043]

Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. It should be noted that the embodiments described below are preferred embodiments of the present invention, and therefore, various technically preferable limitations are added. However, the scope of the present invention is not limited to the following description. The embodiments are not limited to these embodiments unless otherwise specified.

FIGS. 1 to 9 are views showing a scanner device to which the first embodiment of the image reading apparatus of the present invention is applied. In the present embodiment, the average value of the motor speed and the first running are shown. The speed to be fed back is corrected by using the ratio to the target speed of the body as a correction coefficient to perform speed control without speed deviation, and corresponds to claim 1.

In FIG. 1, the scanner device 1 has a contact glass 3 arranged on an upper portion of a main body case 2.
Below the contact glass 3, a first traveling body 6 having a halogen lamp 4 as a light source and a first mirror 5 mounted thereon, and a second traveling body.
A second traveling body 9 equipped with a mirror 7 and a third mirror 8, a lens 10, and a CCD (Charge Coupl) as a photoelectric conversion element.
ed Device) 11 and the like are provided. An original 12 is set on the contact glass 3 with its original surface facing the contact glass 3, and the original 12 set on the contact glass 3 is fed from the halogen lamp 4 mounted on the first traveling body 6 to the original 12. The light source 12 projects the original 12
The reflected light from is reflected by the first mirror 5 mounted on the first traveling body 6 to the second mirror 7 of the second traveling body 9. The second mirror 7 reflects the incident light to the third mirror 8 mounted on the second traveling body 9, and the third mirror 8 projects the incident light to the CCD 11 through the lens 10. CCD 11 is
The incident light is photoelectrically converted to read the image on the original 12.

Then, the first traveling body 6 and the second traveling body 9
2, is guided by the guide plates 13 and 14 so as to be movable in the sub-scanning direction, and the first traveling body 6 is locked by the wire wires 15 stretched in the sub-scanning direction. There is. The second traveling body 9 is engaged with the strand wire 15 via a plurality of pulleys 16, and the strand wire 15
Is wound around the pulley 16 of the second traveling body 9 from the fixed end 17, is connected to the first traveling body 6, is guided by the pulley 16 and is wound around the drive shaft 18a of the motor 18.

Therefore, the first traveling body 6 and the second traveling body 9 move in the same sub-scanning direction as the wire wire 15 moves due to the motor 18 rotating the drive shaft 18a. The first traveling body 6 and the second traveling body 9 move in the sub-scanning direction while keeping the optical path length from the document 12 to the CCD 11 which is the photoelectric conversion means constant. That is, the motor 18 drives the first traveling body 6 at a predetermined set speed, and drives the second traveling body 9 via the wire wires 15 at a speed half that of the first traveling body 6 to drive the first traveling body 6 at a predetermined speed. A sub-scanning system is constructed based on a speed ratio of 2: 1 of the first traveling body 6 and the second traveling body 9.

The motor 18 corresponds to the controller 2 shown in FIG.
It is controlled by 0. That is, the control device 20
A microcomputer 21, a state command unit 22, an interface 23, a drive circuit 24, a motor 18, an encoder 25, an interface 26 and the like are provided, and the microcomputer 21 includes a microprocessor 27, a ROM (Re
ad Only Memory 28 and RAM (Random Access Memo)
ry) 29 etc. In FIG. 3, reference numeral 30 denotes a bus, which includes a microcomputer 21, a state command unit 22,
The interface 23 and the interface 26 are connected by a bus 30.

The microcomputer 21 controls each part of the control circuit 20 and controls the drive of the motor 18 while the microprocessor 27 uses the RAM 29 as a work memory based on the program in the ROM 28. The state command unit 22 determines the state of the motor 18 (target speed).
Is output, that is, a speed command signal or the like, and the microcomputer 21 outputs a drive control signal for driving and controlling the motor 18 to the interface 23 based on the speed command signal.
The interface 23 is an interface device for driving, and as described later, the microcomputer 21
The drive control signal which is a digital value of the calculation result of is converted into a pulsed drive control signal for operating the power semiconductors and the transistors forming the drive circuit 24 and output to the drive circuit 24. The drive circuit 24 operates based on a pulsed drive control signal input via the interface 23, and controls the voltage applied to the motor 18. Motor 18
For example, a DC motor is used, the encoder 25 is incorporated, and the rotation speed thereof is detected by the encoder 25. The encoder 25 outputs the detection result to the interface 26 for state detection, and the interface 26
A counter for converting the output of the encoder 25 into a digital value and counting the output pulse of the encoder 25 is provided.

The interface 26 has its output connected to the interrupt terminal of the microprocessor 27 and is provided with a timer, a register, etc. for counting the reference clock CLK, and the output pulse of the encoder 25 as shown in FIG. Hereinafter, the speed of the motor 18 is detected together with the microprocessor 27 from the encoder output pulse).

That is, as shown in FIG. 4, assuming that the encoder output pulse is in a state immediately before the edge Eg1 arrives, the counter incorporated in the interface 26 determines the encoder output pulse based on the CLK signal. A decrement count is executed from the obtained count value (for example, 0FFFFH), and when the edge Eg1 reaches the interrupt of the microprocessor 27, the microprocessor 27 starts executing the interrupt routine of FIG. When the execution of this interrupt routine is started, the decrement count value of the counter of the interface 26 is latched in the internal register of the interface 26 (step S1), and the latched decrement count value is stored in the RAM 29 of FIG. Store (step S
2). Then, a count initial value (0F for counting the pulse cycle of the encoder output pulse Tn shown in FIG.
FFFH) is given, the decrement count is started again (step S3), and the interrupt processing is ended.
After that, the edge Eg2 is again detected by the microprocessor 27.
When it reaches the interrupt terminal of, the processing of steps S1 to S3 of FIG. 5 is repeated. At this time, the speed v (i) in the encoder output pulse Tn is calculated as follows.

V (i) = k / (Tclk × Ne × n) (1) Here, Tclk: CLK cycle Ne: Encoder division number per unit angle (using 4 multiplication) n: CLK count number = 0FFFFH-decrement count number k: unit conversion constant to speed As described above, the encoder 25 outputs the detection result of the encoder 25 and the count result of the counter to the microcomputer 21. Therefore, the control device 20 detects the rotation speed of the motor 18 by the encoder 25, and through the interface 26, the microcomputer 21.
, And a drive control signal is generated by the microcomputer 21 to control the speed of the motor 18. Although the discrete type microcomputer 21 is used as the control device 20, the control device 20 is not limited to this. For example, a microcomputer in which the state command unit 22, the interface 23 and the interface 26 are integrated into one chip is used. However, the same processing can be performed.

Next, the operation will be described. First, conventional motor speed control using the encoder will be described.

Conventional speed control is performed by the method shown in FIG. That is, the motor 101 detected by the encoder and the interface (similar to the encoder 25 and the interface of the present embodiment)
Speed v (i-1) is given to the arithmetic unit 103 via the feedback loop 102, and the arithmetic unit 103 outputs the control target value output from the state instruction unit similar to the state instruction unit 22 of the present embodiment. R (i) and feedback loop 10
The difference e (i) [difference e (i) = R (i) -v (i-1)] from the signal [speed v (i-1)] from 2 is calculated. The difference e (i) is integrated by the integration unit 104, the result of integration by the integration unit 104 is multiplied by the constant Ki in the multiplication unit 105, and the result is output to the calculation unit 106. At the same time, the calculation unit 103
The difference e (i) calculated in (1) is multiplied by the constant Kp in the multiplication unit 107 and output to the calculation unit 106. Computing unit 106
Calculates the input voltage to the motor 101 by adding the two inputs from the multiplying unit 105 and the multiplying unit 107,
The control voltage value U (i) is output to the electric motor 501. Conventionally, the speed control of the motor 101 is performed by sequentially repeating the above loop.

When the motor 101 is controlled by the conventional speed control method as described above, the first traveling body moves as shown in FIGS.
As shown in, the speed control is performed in a state in which the average speed Vmean fluctuates with a certain fluctuation width with respect to the target speed Vref. Note that FIG. 7 shows a case where the average speed Vmean is slower than the target speed Vref, and FIG. 8 shows that the average speed Vmean is the target speed Vre.
The case is earlier than f. The average speed Vmean is caused by the load of the first traveling body and the second traveling body and the error of the control system. As a result, according to the conventional speed control method, the actual average speed Vmean cannot be perfectly matched with the target speed Vref, which is one of the factors of the magnification error of the image reading apparatus.

Therefore, in the present embodiment, as shown in FIG. 9, the average value of the speed of the motor 18 and the first traveling member 6
The speed control without the speed deviation is performed by correcting the speed to be fed back by using the ratio with the target speed of 1 as the correction coefficient.

That is, the scanner device 1 of the present embodiment
Controls the speed of the motor 18 by performing control processing as shown in FIG. 9 by the microcomputer 21. Specifically, the speed v of the motor 18 detected by the encoder 25 and the interface 26
(I-1) is input to the multiplication unit 32 via the feedback loop 31, and the multiplication unit 32 multiplies the speed v (i-1) by the speed correction coefficient Vcorrec to obtain the feedback loop 3
It is fed back to the calculation unit 34 via the control unit 3. The calculation unit 34 controls the control target value R input from the state command unit 22.
The difference e (i) [e (i)] between (i) and the signal [Vcorrec · v (i-1)] input from the feedback loop 33.
= R (i) -Vcorrec.v (i-1)] is calculated and output to the integration unit 35. The integration unit 35 integrates the difference e (i) input from the calculation unit 34 and outputs an integrated value [Σe (i)] to the multiplication unit 36, and the multiplication unit 36 integrates the integration input from the integration unit 35. The result is multiplied by a constant Ki and output to the calculation unit 37. Further, the arithmetic unit 34 outputs the difference e (i) which is the arithmetic result to the multiplication unit 38, and the multiplication unit 38 multiplies the difference e (i) input from the arithmetic unit 34 by a constant Kp. , To the calculation unit 37. The calculation unit 37 includes a multiplication unit 36.
And the input from the multiplication unit 38 are added,
Input voltage to the motor 18, that is, control voltage u (i)
Is output to the motor 18.

Then, in the multiplication unit 32, the velocity v (i-
The speed correction coefficient Vcorrec multiplied by 1) is the target speed Vr.
ef is a coefficient for correcting the difference between the average value Vmean of the actual speed and the actual value when the first traveling body 6 is controlled in advance in the block diagram of the conventional speed control (see FIG. 6). The average value Vmean of the speeds is calculated in advance, and the ratio between the average value Vmean and the target speed Vref of the scanner optical system, Vmean / Vref, is calculated. Further, the control calculation shown in FIG. 9 including the calculation of the speed detection by the equation (1) can be performed by the numerical calculation in the microcomputer 21, and the speed control can be easily performed.

As described above, according to this embodiment, the average value Vmean of the moving speeds of the first traveling body 6 is obtained in advance, and the average value Vmean and the target speed Vref of the first traveling body 6 are calculated. Since the feedback speed is corrected by using the ratio of the above as the correction coefficient Vcorrec, control without speed deviation can be performed, and the occurrence of magnification error can be suppressed.

FIG. 10 is a diagram showing a scanner device to which the second embodiment of the image reading device of the present invention is applied. In this embodiment, the average value of the moving speed of the first traveling body and the first moving body are shown. The target speed is corrected using the ratio of the target speed of the traveling body as a correction coefficient, and corresponds to claim 2.

The present embodiment is applied to the same scanner device as that of the first embodiment, and the same components as those in FIGS. 1 to 5 and 9 are designated by the same reference numerals. The detailed description thereof will be omitted.

FIG. 10 shows a control block of speed control of the present embodiment. In FIG.
5 and the motor 18 detected by the interface 26
The velocity v (i-1) of 1 is input to the calculation unit 42 via the feedback loop 41. Further, the control target value R (i) is input from the state command unit 22 to the multiplication unit 43, and the multiplication unit 43
Then, the speed correction coefficient 1 / Vcorrec is multiplied, and the calculation unit 42
Output to The calculation section 42 calculates a difference e (i) [e (i) = e [i] [e (i) =) between the result obtained by multiplying the control target value R (i) input from the multiplication section 43 by the speed correction coefficient 1 / Vcorrec and the signal from the feedback loop 41. R (i) / Vcorrec-v (i-
1)] is calculated and output to the multiplication units 35 and 38, and the multiplication unit 35 integrates the difference e (i) input from the calculation unit 34 and outputs it to the multiplication unit 36 in the same manner as above. . The multiplication unit 36 adds a constant K to the integration result input from the integration unit 35.
i is multiplied and output to the arithmetic unit 37, and the multiplication unit 38 multiplies the difference e (i) input from the arithmetic unit 42 by a constant Kp and outputs the result to the arithmetic unit 37. The calculation unit 37 includes a multiplication unit 36.
And the input from the multiplication unit 38 are added,
Input voltage to the motor 18, that is, control voltage u (i)
Is output to the motor 18.

Then, in the multiplication section 43, the control target value R
The speed correction coefficient 1 / Vcorrec to be multiplied by (i) is a coefficient for correcting the difference between the target speed Vref and the average value Vmean of the actual speeds, and similarly to the above, a block diagram of the conventional speed control ( 6), the average value Vmean of the actual speeds when the first traveling body 6 is controlled is obtained, and the ratio of the average value Vmean and the average value of the target speed Vref of the scanner optical system, that is, 1 / (Vmean
/ Vref). The speed correction coefficient 1 / Vcorrec is the reciprocal of the speed correction coefficient Vcorrec obtained in the first embodiment. In addition, the control calculation shown in FIG. 10 including the calculation of the speed detection by the expression (1) can be performed by the numerical calculation in the microcomputer 21, and the speed control can be easily performed.

As described above, according to the present embodiment, the average value Vmean of the moving speed of the first traveling body 6 is obtained in advance, and the average value Vmean and the target speed Vref of the first traveling body 6 are calculated. The ratio of is the correction coefficient 1 / Vcorrec,
Since the target speed Vref is corrected by this correction coefficient 1 / Vcorrec, it is possible to perform control without speed deviation and suppress the occurrence of magnification error.

11 to 13 are views showing a scanner device to which the third embodiment of the image reading device of the present invention is applied. In the present embodiment, a plurality of reading sizes in the sub-scanning direction are set in advance. The average value of the moving speed of the first traveling body is obtained, the ratio between the average value and the target speed of the first traveling body is stored as a correction coefficient table, and the speed to be fed back is corrected based on the table. Does it correspond to claim 3?

The present embodiment is applied to the same scanner device as that of the first embodiment, and in the description of the present embodiment, the reference numerals used in FIGS. 1 to 3 and 9 are used. Will be used as is and will be described below.

The scanner device 1 of this embodiment has the R
In the OM 28, average speeds (Vmean1, Vmean2, Vmean) corresponding to all reading sizes (sizes 1, 2, 3, ...) Required in advance for A3, A4, B5, B4, etc.
3) is calculated in advance, and as shown in FIG. 11, the target speed Vref, the average value Vmean1 of the speeds, and the average value Vm.
ean2, the average value Vmean3, and the ratio (Vme
an1 / Vref, Vmean2 / Vref, Vmea
(n3 / Vref, ...) Is stored as a speed correction coefficient table corresponding to the read size, and the microprocessor 27 performs speed control based on this speed correction coefficient table.

That is, in FIGS. 7 and 8, the actual speed of the first traveling body 6 is represented by the average value Vmean of the speed and the target speed V.
As shown with ref, the average value Vmean of this speed
Are different depending on the reading size, and the average value Vmean1 and the average value Vmean of the speed depending on the reading size.
2, the average value Vmean3, ... Can be shown as in FIG. 12 only when the actual speed is slower than the target speed Vref based on FIG. Here, in the case of the reading size 1, the average value Vmean of the speed is Vme
If the read size is an1, and the read sizes are 2 and 3, the speed average values Vmean2 and Vmean3 are respectively obtained, and the average speed value Vmean has different values depending on the read size.

Therefore, in the present embodiment, the speed correction coefficient Vcorr for each reading size (size 1, 2, 3, ...)
ec (Vcorrec1, Vcorrec2, Vcorrec3, ...) Is obtained and stored in the ROM 28 as a speed correction coefficient table as shown in FIG.
When 2, 3, ... Are input, velocity correction coefficients Vcorrec1, Vcorrec2, Vcorrec3, ... Corresponding to the read sizes 1, 2, 3 ,.
Is read to control the speed.

That is, the scanner device 1 of the present embodiment
First, as shown in the control flow of FIG. 13, the user first inputs the read sizes 1, 2, 3, ... Of the images to be read such as A4, A3, B4, B5 (step S11). ), The speed correction coefficients Vcorrec1, Vcorrec2, Vcorrec3, ... Corresponding to the reading sizes 1, 2, 3, ... Input from the speed correction coefficient table of the ROM 28.
• is determined and substituted for Vcorrec given to the RAM 29 of the microcomputer 21 (step S1
2). After that, the speed of the first traveling body 6 is controlled based on the control block shown in FIG. 9 (step S13), and the image is read (step S14).

As described above, according to this embodiment, the average values Vmean1, Vmean of the moving speeds of the first traveling body 6 in the reading sizes 1, 2, 3, ...
, mean, Vmean1, Vmean2, Vmean are calculated.
.. and the target speed Vref of the first traveling body 6 are stored as a speed correction coefficient table, and the read size 1,
Based on 2, 3, ... From the speed correction coefficient table, speed correction coefficients Vcorrec1, Vcorrec2, Vcorrec3, ...
Is determined, and the speed of feedback is determined by the speed correction coefficients Vcorrec1, Vcorrec2, Vcorrec3 ,. Therefore, even in various reading sizes 1, 2, 3, ..., It is possible to perform speed control without speed deviation and suppress the occurrence of magnification error.

FIG. 14 is a diagram showing a scanner device to which the fourth embodiment of the image reading device of the present invention is applied. In the present embodiment, the first running is performed in advance in a plurality of reading sizes in the sub-scanning direction. The average value of the moving speed of the body is obtained, the ratio between the average value and the target speed of the first traveling body is stored as a table of correction coefficients, and the target speed is corrected based on the table. Does it correspond to claim 4?

The present embodiment is applied to the same scanner device as that of the second embodiment, and in the description of the present embodiment, the reference numerals used in FIGS. 1 to 5 and FIG. Will be used as is and will be described below.

The scanner device 1 of this embodiment has the R
The OM28 has all the necessary reading sizes (size 1,
2, 3, ..., The average speed (Vmean1,
Vmean2, Vmean3, ...)
As shown in FIG. 11, the target speed Vref and the average value Vmean1, the average value Vmean2, and the average value Vmean of the speed.
ratio with n3, ... (Vmean1 / Vref, Vme
an2 / Vref, Vmean3 / Vref, ...)
Is stored as a speed correction coefficient table corresponding to the read size, and the microprocessor 27 performs speed control based on this speed correction coefficient table.

That is, the scanner device 1 of the present embodiment
First, as shown in the control flow of FIG. 14, the user first inputs the read sizes 1, 2, 3, ... Of the images to be read such as A4, A3, B4, B5 (step S21). ), The speed correction coefficients Vcorrec1, Vcorrec2, Vcorrec3, ... Corresponding to the reading sizes 1, 2, 3, ... Input from the speed correction coefficient table of the ROM 28.
· Is determined and is substituted into Vcorrec given to the RAM 29 of the microcomputer 21 (step S2
2). After that, the speed of the first traveling body 6 is controlled based on the control block shown in FIG. 10 (step S23), and the image is read (step S24). And the target speed R
Speed correction coefficient determined in (i) Speed correction coefficient Vcorrec
, Vcorrec2, Vcorrec3, ... Are multiplied by the multiplication unit 43 to obtain a new target speed, and feedback control is performed according to this target speed.

As described above, according to the present embodiment, the average values Vmean1, Vmean of the moving speeds of the first traveling body 6 in the reading sizes 1, 2, 3, ...
, mean, Vmean1, Vmean2, Vmean are calculated.
.. and the target speed Vref of the first traveling body 6 are stored as a speed correction coefficient table, and the read size 1,
Based on 2, 3, ... From the speed correction coefficient table, speed correction coefficients Vcorrec1, Vcorrec2, Vcorrec3, ...
・ Determined and determined velocity correction factors Vcorrec1, Vcorr
The target speed is corrected by ec2, Vcorrec3, .... Therefore, various read sizes 1, 2, 3,
Even in the case of ..., Speed control without speed deviation can be performed, and the occurrence of magnification error can be suppressed.

In the above fourth embodiment,
Speed correction coefficients Vcorrec1, V for each reading size 1, 2, 3, ... As shown in FIG. 12 in the speed correction coefficient table.
It stores correc2, Vcorrec3, ...
As shown in 5, the reciprocal of the speed correction coefficient 1 / Vcorrec1
(Vref / Vmean1), 1 / Vcorrec2 (Vre
f / Vmean2), 1 / Vcorrec3 (Vref / Vm
, etc. are stored in the ROM 28 as a speed correction coefficient table, and the read sizes 1, 2,
As soon as 3, ... Is input, the multiplication unit 4 in FIG.
3 may be substituted and the speed control may be performed by the speed control method shown in FIG.

16 to 18 are views showing a scanner device to which the fifth embodiment of the image reading device of the present invention is applied. In this embodiment, a plurality of reading sizes in the sub-scanning direction are set in advance. The average value of the moving speed of the first traveling body is obtained, the ratio between the average value and the target speed of the first traveling body is stored as a correction coefficient table, and the speed to be fed back is corrected based on the table. In addition, when the read size is not the read size stored in advance in the table, the document is pre-scanned to determine the speed correction coefficient and the speed to be fed back is corrected. Corresponding.

Note that this embodiment is applied to the same scanner device as that of the first embodiment, and in the description of this embodiment, the same configuration as in FIGS. 1 to 5 and 9 is used. The same reference numerals are given to the parts, and detailed description thereof will be omitted.

The scanner device 1 of this embodiment has the R
A plurality of reading sizes (sizes 1, 2,
3, average speed (Vmean1, Vm)
ean2, Vmean3, ...
As shown in 1, the target speed Vref and the average value V of the speeds
mean1, average value Vmean2, average value Vmean
3, ratio with (Vmean1 / Vref, Vmea
n2 / Vref, Vmean3 / Vref, ...) Is stored as a speed correction coefficient table corresponding to the read size, and the microprocessor 27 performs speed control based on this speed correction coefficient table.

FIG. 16 shows a scanner device 1 according to this embodiment.
17 is a block diagram for obtaining a speed correction coefficient by the pre-scan of FIG. 16, the speed v of the motor 18 detected by the encoder 25 and the interface 26 in FIG.
(I-1) is input to the calculation unit 34 via the feedback loop 50, and also the signal on / off processing unit 5
1 is input. The calculation unit 34 calculates the control target value R (i) output from the state command unit 22 and the feedback loop 5
Difference e with the signal [speed v (i-1)] input from 0
(I) is calculated and output to the integration unit 35. Integrator 35
Integrates the difference e (i) input from the calculation unit 34 and outputs it to the multiplication unit 36. The multiplication unit 36 multiplies the integration result input from the integration unit 35 by a constant Ki, and calculates the calculation unit 37. Output to. Further, the arithmetic unit 34 outputs the difference e (i) which is the arithmetic result to the multiplication unit 38, and the multiplication unit 38 multiplies the difference e (i) input from the arithmetic unit 34 by a constant Kp. , To the calculation unit 37. The calculation unit 37 includes a multiplication unit 36.
And the input from the multiplication unit 38 are added,
Input voltage to the motor 18, that is, control voltage u (i)
Is output to the motor 18.

On the other hand, the signal on / off processing section 51 is turned on when the read size does not correspond to the read size 1, 2, 3, ... Stored in the ROM 28 in advance, and when it is on, the encoder 25 and The speed v (i−1) of the motor 18 detected by the interface 26 is output to the integrator 52. The integrator 52 integrates the speed v (i−1) input from the signal on / off processor 51 (Σv (i−
1)) The microcomputer 21 divides this integral value (Σv (i-1)) by the total number of integrals to calculate the average value Vmean of the speed, and the average value Vmean of this speed.
Corresponds to the read size.

That is, the scanner device 1 of the present embodiment
For each read size (size 1, size 2, size 3,
...) speed correction coefficient Vcorrec (Vcorrec1, Vcorr
ec2, Vcorrec3, ...) Is obtained and stored in the ROM 28 as a speed correction coefficient table as shown in FIG. 12, and as shown in FIG.
When the read sizes 1, 2, 3, ... Of images to be read such as A4, A3, B4, B5, etc. are input (step S31),
It is checked whether or not the input read size is stored in the speed correction coefficient table of the ROM 28 (step S
32), if the input read size is stored in the ROM 28, the speed correction coefficients Vcorrec1, Vcorrec2, Vcorrec3 corresponding to the read sizes 1, 2, 3, ... ... is determined and substituted for Vcorrec given to the RAM 29 of the microcomputer 21 (step S33).
After that, the speed of the first traveling body 6 is controlled based on the control block shown in FIG. 9 (step S34), and the image is read (step S35).

In step S32, when the input read sizes 1, 2, 3, ... Are not stored in the speed correction coefficient table of the ROM 28, the sub-scan drive is performed by the control block for prescan shown in FIG. Then, the average value Vmean of the speed is calculated (step S36). next,
The speed correction coefficient, that is, the ratio (Vmea) between the average value Vmean of the speeds obtained in step S36 and the target speed Vref.
n / Vref) is determined and substituted for Vcorrec given to the RAM 29 of the microcomputer 21 (step S37). After that, the speed of the first traveling body 6 is controlled by the speed control method shown in FIG. 9 (step S34), and the image is read (step S35).

Next, the on / off control processing of the signal on / off processing unit 51 in the pre-scan control block diagram of FIG. 16 will be described based on the flow of FIG.

.., which are input in step S32 of FIG. 17, are not stored in the speed correction coefficient table, and when the sub-scanning drive is started in step S36, FIG. The flow of starts. First, it is checked whether the first traveling body 6 has reached the reading start position (step S41). When the first traveling body 6 has not reached the reading start position, the first traveling body 6 reaches the reading start position. After waiting for that, the signal on / off processing unit 51 of FIG. 16 is turned on (step S42). As a result, the speed v (i−1) of the motor 18 is input from the signal on / off processing unit 51 to the integration unit 52, and the speed v of the motor 18 is calculated by the integration unit 52.
The integration of (i-1) is started. Next, it is checked whether the first traveling body 6 has reached the reading end position (step S4).
3) When the first traveling body 6 has not reached the reading end position, the process returns to step S42, and the signal on / off processing unit 51 is turned on until the first traveling body 6 reaches the reading end position. The integration of the speed v (i-1) of the motor 18 continues. In step S43, when the first traveling body 6 reaches the reading end position, it is determined that the pre-scan has ended,
Signal ON / pre-scan control block diagram (Fig. 16)
The off processing unit 51 is turned off (step S44), the sub-scanning drive is ended, and the pre-scan processing is ended.

Since the integral value (Σv (i-1)) of the speed v (i-1) of the motor 18 is the value when only the portion corresponding to the read size is scanned, when the prescan is completed. Immediately, the integral value (Σv (i-1)) is divided by the total number of integrals to calculate the average velocity value Vmean, and the average velocity value Vmean at this time corresponds to the read size.

Based on the average value Vmean of this speed,
As shown in FIG. 17, by controlling the speed of the first traveling body 6 based on the reading control block diagram (FIG. 9), R
Even when the reading size not stored in the OM 28 is designated, the speed control of the first traveling body 6 can be appropriately performed.

As described above, according to the present embodiment, the average values Vmean1, Vmean of the moving speeds of the first traveling body 6 in the reading sizes 1, 2, 3, ...
, mean, Vmean1, Vmean2, Vmean are calculated.
.. and the target speed Vref of the first traveling body 6 are stored as a speed correction coefficient table, and the read size 1,
Based on 2, 3, ... From the speed correction coefficient table, speed correction coefficients Vcorrec1, Vcorrec2, Vcorrec3, ...
・ The speed v of the first traveling body 6 for determining and feeding back
The correction of (i-1) can be performed.

Even when a read size other than the read size stored in advance in the speed correction coefficient table is designated, prescan is performed to determine the speed correction coefficient,
The speed to be fed back can be corrected based on the determined speed correction coefficient, and the speed control without speed deviation can be performed for all reading sizes. As a result, it is possible to appropriately suppress the occurrence of a magnification error regardless of the read size.

Then, the read size stored in the speed correction coefficient table is set to a specified size such as A3, A4, etc., and the read size deviated from the other specified size is determined by prescanning to determine the speed correction coefficient. Of course, by doing so, more practical speed control can be performed.

FIG. 19 is a diagram showing a scanner device to which the sixth embodiment of the image reading device of the present invention is applied. In the present embodiment, the first running is performed in advance in a plurality of reading sizes in the sub-scanning direction. The average value of the moving speed of the body is obtained, the ratio between the average value and the target speed of the first traveling body is stored as a table of correction coefficients, and the target speed is corrected based on the table and read. When the size is not the read size stored in advance in the table, the document is pre-scanned to determine the speed correction coefficient and the target speed is corrected, which corresponds to claims 6 and 7. .

The present embodiment is applied to the same scanner device as the second embodiment, and in the description of the present embodiment, the same configuration as that of FIGS. 1 to 5 and FIG. The same reference numerals are given to the parts, and detailed description thereof will be omitted.

As in the fifth embodiment, the scanner device 1 according to the present embodiment has an average speed in the ROM 28 corresponding to a plurality of reading sizes (sizes 1, 2, 3, ...) In advance. (Vmean1, Vmean2, Vmean3, ...
..) is calculated in advance, and as shown in FIG. 11, the target speed Vref, the average value Vmean1 of the speeds, and the average value Vmea.
n2, the average value Vmean3, and the ratio (Vmean
1 / Vref, Vmean2 / Vref, Vmean3
/ Vref, ...) Read size 1, 2, 3, ...
It is stored as a speed correction coefficient table corresponding to, and the microprocessor 27 performs speed control based on this speed correction coefficient table.

The scanner device 1 of this embodiment is shown in FIG.
A pre-scan control block similar to the above is provided, and when the read size does not correspond to the read size stored in the ROM 28 in advance, the speed v (i−1) of the motor 18 is integrated [Σ
v (i-1)] and divide this integrated value [Σv (i-1)] by the total number of integrations to calculate the average value Vmean of the speeds corresponding to the pre-scanned read size.

That is, the scanner device 1 of the present embodiment
For each read size (size 1, size 2, size 3,
...) speed correction coefficient Vcorrec (Vcorrec1, Vcorr
ec2, Vcorrec3, ...) Is calculated and stored in the ROM 28 as a speed correction coefficient table as shown in FIG. 11, and as shown in FIG.
When the reading sizes 1, 2, 3, ... Of images to be read such as A4, A3, B4, B5, etc. are input (step S41),
It is checked whether or not the input read size is stored in the speed correction coefficient table of the ROM 28 (step S
42) If the input read size is stored in the ROM 28, the speed correction coefficients Vcorrec1, Vcorrec2, Vcorrec3 corresponding to the read sizes 1, 2, 3, ... ... is determined and substituted for Vcorrec given to the RAM 29 of the microcomputer 21 (step S43).
After that, the speed of the first traveling body 6 is controlled based on the control block shown in FIG. 10 (step S44), and the image is read (step S45).

In step S42, when the input read size is not stored in the speed correction coefficient table of the ROM 28, the pre-scan control block shown in FIG. 16 drives the sub-scan to calculate the average speed value Vmean. (Step S46). Next, the speed correction coefficient, that is, the ratio (Vmean / Vref) between the average value Vmean of the speeds obtained in step S46 and the target speed Vref is determined and substituted into Vcorrec given to the RAM 29 of the microcomputer 21 ( Step S47). After that, the speed of the first traveling body 6 is controlled by the speed control method shown in FIG. 10 (step S44), and the image is read (step S45).

The on / off control processing of the signal on / off processing section 51 in the pre-scan control block diagram is performed based on the flow of FIG. As shown in FIG. 19, based on the average value Vmean of the speeds, the speed of the first traveling body 6 is controlled based on the read control block diagram (FIG. 10), so that the read size not stored in the ROM 28 is read. Even when is designated, the speed control of the first traveling body 6 can be appropriately performed.

As described above, according to the present embodiment, the average values Vmean1, Vmean of the moving speeds of the first traveling body 6 in the plurality of reading sizes 1, 2, 3, ... In the sub-scanning direction are set in advance.
, mean, Vmean1, Vmean2, Vmean are calculated.
.. and the target speed Vref of the first traveling body 6 are stored as a speed correction coefficient table, and the read size 1,
Based on 2, 3, ... From the speed correction coefficient table, speed correction coefficients Vcorrec1, Vcorrec2, Vcorrec3, ...
・ You can determine and correct the target speed.

Further, even when a read size other than the read size stored in advance in the speed correction coefficient table is designated, prescan is performed to determine the speed correction coefficient to correct the target speed. . As a result, it is possible to perform speed control without speed deviation for all reading sizes, and it is possible to suppress the occurrence of magnification errors.

Then, the read size stored in the speed correction coefficient table is set to a specified size such as A3 or A4, and the read size deviated from the other specified size is determined by prescanning to determine the speed correction coefficient. However, by doing so, more practical speed control can be performed.

FIG. 20 is a diagram showing a scanner device to which the seventh embodiment of the image reading device of the present invention is applied. In this embodiment, when the reading size is designated, the document is pre-scanned. The speed correction coefficient is determined in accordance with the above, and the speed to be fed back is corrected, which corresponds to claim 8.

Note that this embodiment is applied to the same scanner device as that of the first embodiment, and in the description of this embodiment, FIGS. 1 to 5, 9, and 16 will be described.
The following description will be given using the same reference numerals as used in.

Like the fifth embodiment, the scanner device 1 of the present embodiment does not store the speed correction coefficient table in the ROM 28 thereof, and performs the prescan for the input image reading range. , Determine the speed correction factor,
The speed to be fed back is corrected by the determined speed correction coefficient.

The scanner device 1 of the present embodiment is shown in FIG.
A control block for prescan similar to
When a specified read size such as 3, B4, B5 or an arbitrary read size is input, the speed v (i-
1) is integrated (Σv (i-1)), and the integrated value (Σv
(I-1)) is divided by the total number of integrals to calculate an average value Vmean of speeds corresponding to the read size,
A correction coefficient for correcting the feedback speed v (i-1) is determined.

That is, as shown in FIG. 20, when the user inputs a prescribed or arbitrary reading size 1, 2, 3, ... Of A4, A3, B4, B5, etc. (step S51). , Sub-scanning is driven by the pre-scan control block shown in FIG.
n is calculated (step S52). Next, the speed correction coefficient, that is, the average value Vmean of the speed and the target speed Vr.
The ratio (Vmean / Vref) with ef is determined, and Vco provided to the RAM 29 of the microcomputer 21.
Substitute for rrec (step S53). After that, the speed of the first traveling body 6 is controlled by the speed control method shown in FIG. 9 (step S54), and the image is read (step S55).

The on / off control processing of the signal on / off processing section 51 in the pre-scan control block diagram of FIG. 16 is performed based on the flow of FIG.

As described above, according to this embodiment, it is possible to perform the prescan, determine the speed correction coefficient, and correct the speed to be fed back. As a result, it is possible to perform speed control without any speed deviation for all reading sizes and even when there is a change over time in the scanner device, and it is possible to further suppress the occurrence of magnification errors.

FIG. 21 is a diagram showing a scanner device to which the eighth embodiment of the image reading device of the present invention is applied. In this embodiment, when the reading size is designated, the document is pre-scanned. The target speed is corrected by determining the speed correction coefficient in accordance with claim 9 and corresponds to claim 9.

Note that this embodiment is applied to the same scanner device as that of the second embodiment, and in the description of this embodiment, FIGS. 1 to 5, 10, and 1 are shown.
The same reference numerals used in 6 will be used for the following description.

Like the fifth embodiment, the scanner device 1 of the present embodiment does not store the speed correction coefficient table in the ROM 28 thereof, and performs the prescan for the input image reading range. , Determine the speed correction factor,
The target speed is corrected by the determined speed correction coefficient.

The scanner device 1 of the present embodiment is shown in FIG.
A control block for prescan similar to
When a specified read size such as 3, B4, B5 or an arbitrary read size is input, the speed v (i-
1) is integrated (Σv (i-1)), and the integrated value (Σv
(I-1)) is divided by the total number of integrals to calculate an average value Vmean of speeds corresponding to the read size,
A correction coefficient for correcting the target speed is determined.

That is, as shown in FIG. 21, when the user inputs a prescribed or arbitrary reading size 1, 2, 3, ... Of A4, A3, B4, B5, etc. (step S61). , Sub-scanning is driven by the pre-scan control block shown in FIG.
n is calculated (step S62). Next, the speed correction coefficient, that is, the average value Vmean of the speed and the target speed Vr.
The ratio (Vmean / Vref) with ef is determined, and Vco provided to the RAM 29 of the microcomputer 21.
Substitute for rrec (step S63). After that, the speed of the first traveling body 6 is controlled by the speed control method shown in FIG. 10 (step S64), and the image is read (step S65).

The on / off control processing of the signal on / off processing section 51 in the pre-scan control block diagram of FIG. 16 is performed based on the flow of FIG.

As described above, according to this embodiment, it is possible to perform the prescan, determine the speed correction coefficient, and correct the target speed. As a result, it is possible to perform speed control without any speed deviation for all reading sizes and even when there is a change over time in the scanner device, and it is possible to further suppress the occurrence of magnification errors.

Although the invention made by the present inventor has been specifically described based on the preferred embodiments, the present invention is not limited to the above, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

For example, in each of the above-described embodiments, the case where PI control is performed has been described as an example of feedback control, but the present invention is not limited to PI control, and P control, I control, PID control, modern control theory, etc. The same applies to any control theory.

[0118]

According to the image reading apparatus of the present invention, the moving speed of the first traveling body is detected, the moving speed is fed back, and the moving speed of the first traveling body is fed back to the target speed. In controlling, the average moving speed of the first traveling body is obtained in advance, and the moving speed fed back as a correction coefficient is corrected by the ratio of the average traveling speed and the target speed of the first traveling body. Therefore, there is no speed deviation. Speed control can be performed, and an image with no magnification error can be read.

According to the image reading apparatus of the second aspect, the moving speed of the first traveling body is detected, the moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to the target speed. At this time, the average moving speed of the first traveling body is obtained in advance, and the target speed is corrected using the ratio of the average moving speed and the target speed of the first traveling body as a correction coefficient. Therefore, speed control without speed deviation is performed. Therefore, it is possible to read an image without causing a magnification error.

According to the image reading apparatus of the third aspect, the moving speed of the first traveling body is detected, the moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to the target speed. At this time, the average moving speed of the first traveling body in a plurality of reading sizes in the sub-scanning direction is obtained in advance, and the ratio of the average moving speed and the target speed of the first traveling body is stored as a table, and when the original is read, the original is read. It is possible to determine the correction coefficient from the table according to the read size of the above, and multiply the feedback moving speed by the determined correction coefficient to correct the feedback moving speed. As a result, it is possible to perform control without speed deviation for various reading sizes, and it is possible to read an image with no magnification error.

According to the image reading apparatus of the fourth aspect, the moving speed of the first traveling body is detected, this moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to the target speed. At this time, the average moving speed of the first traveling body in a plurality of reading sizes in the sub-scanning direction is obtained in advance, and the ratio of the average moving speed and the target speed of the first traveling body is stored as a table, and when the original is read, the original is read. It is possible to correct the target speed by determining the correction coefficient from the table in accordance with the read size and multiplying the target speed by the determined correction coefficient. As a result, it is possible to perform control without speed deviation for various reading sizes, and it is possible to read an image with no magnification error.

According to the image reading apparatus of the fifth aspect, the moving speed of the first traveling body is detected, the moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to the target speed. At this time, as a method of obtaining the correction coefficient of the moving speed to be fed back in a plurality of reading sizes, the method of obtaining the correction coefficient in advance in the table and the method of obtaining it in the pre-scan are used together,
By setting the correction coefficient corresponding to more various reading sizes,
The moving speed to be fed back can be corrected, and the moving speed to be fed back can be corrected more practically for any reading size. As a result, it is possible to perform speed control without speed deviation for all reading sizes, and it is possible to read an image with no magnification error.

According to the image reading apparatus of the sixth aspect, the moving speed of the first traveling body is detected, the moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to the target speed. At this time, as a method of obtaining the correction coefficient of the target speed for a plurality of reading sizes, a method of previously obtaining the correction coefficient and making a table and a method of obtaining the same at the time of pre-scan are used together. A coefficient can be set to correct the target speed and the target speed correction can be more practically applied to any read size. As a result, it is possible to perform speed control without speed deviation for all reading sizes, and it is possible to read an image with no magnification error.

According to the image reading apparatus of the seventh aspect of the present invention, since the correction coefficient is stored as a table only for the read size of the specified size, the correction of the moving speed and the target speed for more practical feedback can be performed. It can be carried out.

According to the image reading apparatus of the present invention, the moving speed of the first traveling body is detected, this moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to the target speed. At this time, the average traveling speed of the first traveling body is calculated according to the read size during the pre-scan, and the traveling speed to be fed back is corrected using the ratio of the average traveling speed and the target speed of the first traveling body as a correction coefficient. Therefore, even if the image reading apparatus changes with time, it is possible to always accurately correct the speed deviation.

According to the image reading apparatus of the present invention, the moving speed of the first traveling body is detected, the moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to the target speed. At that time, since the average moving speed of the first traveling body is obtained according to the read size during the pre-scan, and the target speed is corrected by using the ratio of the average moving speed and the target speed of the first traveling body as a correction coefficient, Even if a change with time occurs in the image reading apparatus, it is possible to always correct the speed deviation accurately.

[Brief description of drawings]

FIG. 1 is a side sectional view of a main part of a scanner device to which a first embodiment of an image reading device of the present invention is applied.

FIG. 2 is a perspective view of an optical system of the scanner device of FIG.

3 is a circuit block diagram of a main part of the scanner device of FIG.

4 is a timing diagram of an output of the encoder of FIG. 3 and a reference clock.

5 is a flowchart showing an interrupt process for counting output pulses of an encoder by the microcomputer of FIG.

FIG. 6 is a control block diagram showing conventional speed control.

FIG. 7 is a diagram showing the speed of the first traveling body when the actual speed is controlled to be slower than the target speed.

FIG. 8 is a diagram showing the speed of the first traveling body when the actual speed is controlled to be higher than the target speed.

9 is a control block diagram showing speed control by the scanner device of FIG. 1. FIG.

FIG. 10 is a control block diagram showing speed control by a scanner device to which the second embodiment of the image reading device of the present invention is applied.

FIG. 11 is a diagram showing an example of a speed correction coefficient table for each reading size, which is stored in the ROM of the scanner device to which the third embodiment of the image reading device of the present invention is applied.

FIG. 12 is a diagram showing a difference in average speed for each reading size.

FIG. 13 is a flowchart showing speed control processing by the scanner device according to the third embodiment of the image reading device of the invention.

FIG. 14 is a flowchart showing speed control processing by the scanner device according to the fourth embodiment of the image reading device of the invention.

FIG. 15 is a diagram showing another example of the speed correction coefficient table for each image reading size stored in the ROM used in the scanner device of the fourth embodiment of the image reading device of the present invention.

FIG. 16 is a control block diagram for obtaining a speed correction coefficient by prescanning by the scanner device according to the fifth embodiment of the image reading device of the present invention.

FIG. 17 is a flowchart showing a speed control process by the scanner device of the fifth embodiment of the image reading device of the invention.

FIG. 18 is a flowchart showing an on / off control process of a signal on / off processing unit at the time of prescan by the scanner device of the fifth embodiment of the image reading device of the invention.

FIG. 19 is a flowchart showing a speed control process by the scanner device according to the sixth embodiment of the image reading device of the invention.

FIG. 20 is a flowchart showing speed control processing by the scanner device according to the seventh embodiment of the image reading device of the present invention.

FIG. 21 is a flowchart showing a speed control process by the scanner device according to the eighth embodiment of the image reading device of the invention.

[Explanation of symbols]

 1 Scanner Device 2 Main Body Case 3 Contact Glass 4 Halogen Lamp 5 First Mirror 6 First Traveling Body 7 Second Mirror 8 Third Mirror 9 Second Traveling Body 10 Lens 11 CCD 12 Originals 13 and 14 Guide Plate 15 Wire Wire 18 Motor 20 Control device 21 Microcomputer 22 State command unit 23 Interface 24 Drive circuit 25 Encoder 26 Interface 27 Microprocessor 28 ROM 29 RAM 30 Bus 31 Feedback loop 32 Multiplying unit 33, 41, 50 Feedback loop 34, 37, 42 Computing unit 35 Integrator 36, 38, 43 Multiplier 51 Signal on / off processor 52 Integrator

Claims (9)

[Claims] 1. A light source that irradiates a document and an optical system that introduces light reflected by the document into a photoelectric conversion element are separately mounted on a first traveling body and a second traveling body, and the first traveling body is driven. When the second traveling body is moved in the sub-scanning direction by the means, the second traveling body is driven by the speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction, the image of the original is read, and the first traveling body is moved. In the image reading device, the moving speed detecting means detects the moving speed of the body, the detected moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to a predetermined target speed. Based on the detection result of
By calculating an average moving speed of the traveling body in advance and multiplying the moving speed of the fed-back first traveling body by using a ratio of the average traveling speed and the target speed of the first traveling body as a correction coefficient. An image reading apparatus that corrects the moving speed to be fed back. 2. A light source for irradiating a document and an optical system for introducing light reflected by the document into a photoelectric conversion element are separately mounted on a first traveling body and a second traveling body, and the first traveling body is driven. When the second traveling body is moved in the sub-scanning direction by the means, the second traveling body is driven by the speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction, the image of the original is read, and the first traveling body is moved. In the image reading device, the moving speed detecting means detects the moving speed of the body, the detected moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to a predetermined target speed. Based on the detection result of
The target moving speed of the traveling body is calculated in advance, and the target speed of the first traveling body is multiplied by using the ratio of the average moving speed and the target speed of the first traveling body as a correction coefficient. An image reading device characterized by correcting speed. 3. A light source for irradiating an original with light and an optical system for introducing light reflected by the original into a photoelectric conversion element are separately mounted on a first traveling body and a second traveling body, and the first traveling body is driven. When the second traveling body is moved in the sub-scanning direction by the means, the second traveling body is driven by the speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction, the image of the original is read, and the first traveling body is moved. In the image reading device, the moving speed detecting means detects the moving speed of the body, the detected moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to a predetermined target speed. Based on the detection result of 1., the average moving speed of the first traveling body in a plurality of reading sizes in the sub-scanning direction is calculated in advance, and the average traveling speed of the plurality of reading sizes and the target speed of the first traveling body are calculated. The ratio of Then, a correction coefficient corresponding to the size of the document to be read is read from the correction coefficient table and multiplied by the moving speed of the first traveling body to be fed back to correct the moving speed to be fed back. An image reading apparatus characterized by: 4. A light source for irradiating a document and an optical system for introducing light reflected by the document into a photoelectric conversion element are separately mounted on a first traveling body and a second traveling body, and the first traveling body is driven. When the second traveling body is moved in the sub-scanning direction by the means, the second traveling body is driven by the speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction, the image of the original is read, and the first traveling body is moved. In the image reading device, the moving speed detecting means detects the moving speed of the body, the detected moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to a predetermined target speed. Based on the detection result of 1., the average moving speed of the first traveling body in a plurality of reading sizes in the sub-scanning direction is calculated in advance, and the average traveling speed of the plurality of reading sizes and the target speed of the first traveling body are calculated. The ratio of The target speed is corrected by reading the correction coefficient corresponding to the size of the document to be read out from the correction coefficient table and multiplying the target speed of the first traveling body by the correction coefficient table. Image reading device. 5. A light source for irradiating a document and an optical system for introducing light reflected by the document into a photoelectric conversion element are separately mounted on a first traveling body and a second traveling body, and the first traveling body is driven. When the second traveling body is moved in the sub-scanning direction by the means, the second traveling body is driven by the speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction, the image of the original is read, and the first traveling body is moved. In the image reading device, the moving speed detecting means detects the moving speed of the body, the detected moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to a predetermined target speed. Based on the detection result of 1., the average moving speed of the first traveling body in a plurality of reading sizes in the sub-scanning direction is calculated in advance, and the average traveling speed of the plurality of reading sizes and the target speed of the first traveling body are calculated. The ratio of If the correction coefficient is stored in the correction coefficient table corresponding to the size of the document to be read, the correction coefficient is read and multiplied by the moving speed of the first traveling body to be fed back. Accordingly, the moving speed to be fed back is corrected, and if the correction coefficient is not stored in the correction coefficient table corresponding to the size of the document to be read, the document is pre-scanned and the first traveling member By calculating the average moving speed of the above, calculating the ratio of the average moving speed and the target speed of the first traveling body as a correction coefficient, and multiplying by the moving speed of the first traveling body to be fed back. An image reading apparatus, wherein the moving speed is corrected. 6. A light source that irradiates a document and an optical system that introduces light reflected by the document into a photoelectric conversion element are separately mounted on a first traveling body and a second traveling body, and the first traveling body is driven. When the second traveling body is moved in the sub-scanning direction by the means, the second traveling body is driven by the speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction, the image of the original is read, and the first traveling body is moved. In the image reading device, the moving speed detecting means detects the moving speed of the body, the detected moving speed is fed back, and the moving speed of the first traveling body is feedback-controlled to a predetermined target speed. Based on the detection result of 1., the average moving speed of the first traveling body in the reading sizes in the sub-scanning direction is calculated in advance, and the average traveling speed of the plurality of reading sizes and the target speed of the first traveling body are calculated. The ratio of When the correction coefficient is stored in the correction coefficient table corresponding to the size of the document to be read, the correction coefficient is read out and is multiplied by the target speed of the first traveling body. , The target speed is corrected, and if the correction coefficient is not stored in the correction coefficient table corresponding to the size of the original to be read, the original is pre-scanned to determine the average moving speed of the first traveling body. Correcting the target speed by calculating the ratio of the average moving speed and the target speed of the first traveling body as a correction coefficient, and multiplying by the target speed of the first traveling body. An image reading device characterized by. 7. The plurality of read sizes in which the correction coefficients are stored in the correction coefficient table are A3, A4, and B.
7. The image reading device according to claim 5, wherein the image reading device has a specified reading size of 4, B5, or the like. 8. A light source for irradiating a document and an optical system for introducing light reflected by the document to a photoelectric conversion element are separately mounted on a first traveling body and a second traveling body, and the first traveling body is driven. When the second traveling body is moved in the sub-scanning direction by the means, the second traveling body is driven by the speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction, the image of the original is read, and the first traveling body is moved. An image reading apparatus that detects a moving speed of a body by a moving speed detecting unit, feeds back the detected moving speed, and feedback-controls the moving speed of the first traveling body to a predetermined target speed. , Prescanning the original over the reading size, calculating an average moving speed of the first traveling body based on the detection result of the moving speed detecting means, and calculating the average traveling speed and the target of the first traveling body. Complement the ratio with speed The image reading apparatus is characterized in that the moving speed of the first traveling body to be fed back is multiplied as a positive coefficient to correct the moving speed to be fed back. 9. A light source that irradiates a document and an optical system that introduces light reflected by the document into a photoelectric conversion element are separately mounted on a first traveling body and a second traveling body, and the first traveling body is driven. When the second traveling body is moved in the sub-scanning direction by the means, the second traveling body is driven by the speed ratio of 2: 1 with respect to the first traveling body and is moved in the sub-scanning direction, the image of the original is read, and the first traveling body is moved. An image reading apparatus that detects a moving speed of a body by a moving speed detecting unit, feeds back the detected moving speed, and feedback-controls the moving speed of the first traveling body to a predetermined target speed. , Prescanning the original over the reading size, calculating an average moving speed of the first traveling body based on the detection result of the moving speed detecting means, and calculating the average traveling speed and the target of the first traveling body. Complement the ratio with speed An image reading apparatus that corrects the target speed by multiplying the target speed of the first traveling body as a positive coefficient.