JPH07199369A - Traveling body driving device - Google Patents

Abstract

PURPOSE:To provide a traveling body driving device which is constituted small in size and inexpensively by omitting an encoder setting area and which performs accurate feedback control of a motor. CONSTITUTION:In this traveling body driving device for an image reader which reads an original image by setting either a 1st traveling body 6 or a 2nd traveling body 10 as a mainly driven side and directly driving it by the motor 18, and submissively driving the other by using plural movable pulleys 19a to 19d and transmission means 20 and 21 so that the traveling bodies may be moved in the speed ratio of 2:1 in a subscanning direction Y; a rotary encoder 24 generating an output signal for controlling the motor 18 for direct driving is arranged in at least one of the pulleys 19a to 19d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving body driving apparatus for an image reading apparatus.

[0002]

2. Description of the Related Art Conventionally, there is provided a first traveling body that holds a first optical system including a light source and a mirror, and a second traveling body that holds a second optical system including a mirror group and that interlocks with the first traveling body. , One of the first and second traveling bodies is the main drive side and is directly driven by a motor,
An example of a traveling body driving device of an image reading apparatus that reads a document image by moving the other traveling body by using a plurality of movable pulleys and a transmission means and moving it in the sub-scanning direction is disclosed in, for example, Japanese Patent Laid-Open No. 23435/1993. "Traveler drive"
And Japanese Patent Application No. 4-338218.
No. 6,096,097, filed as "traveling body drive device", and these are all filed by the applicant.
In the former example, a wire is wound around one side or both sides of the first and second traveling bodies that move in the same direction at a speed ratio of 2: 1, and either one of the first and second traveling bodies travels. The body is driven by a linear motor, and the other traveling body is linked by the action of the wire and the moving pulley. As a result, vibration does not occur in the transmission / conversion system as compared to the conventional drive system in which the power of the rotary motor is linearly converted by a rotation-linear conversion system such as a gear + wire system to drive the traveling body. Highly accurate sub-scanning drive becomes possible. Further, in the latter example, a steel belt is wound around instead of the wire as described above, and either the first or second traveling body is driven by the linear motor or the ultrasonic motor to move in the sub scanning direction. We are trying to improve the precision of driving.

[0003]

SUMMARY OF THE INVENTION In these conventional examples,
By mainly using a linear motor as a drive source in the sub-scanning direction, the accuracy of the drive in the sub-scanning direction is improved. Generally, in such a traveling body drive device, it is desirable to make the guide rails completely parallel to the sub-scanning direction, but it is almost impossible in practice, and the guide rails themselves have a certain curvature. Is normal.
If the guide rail has such a curvature, the position of the encoder (which senses the speed and movement position in the sub-scanning direction) and the position of the motor (linear motor) are different, so an accurate motor control signal can be obtained. No, it is not possible to perform accurate feedback control. Moreover,
In any of the conventional examples as described above, no feedback control using an encoder that senses the speed or movement position in the sub-scanning direction is mentioned in any case, and more precise drive control is required. I can't say I'm going.

Further, since the encoder is often installed integrally with the traveling body and the motor, replacement work is usually troublesome when the encoder fails. In particular, in the case of a linear encoder that has been often used in the past, the replacement work becomes difficult because it is installed over the entire scanning movable range, and at the same time, the replacement of the encoder over the entire scanning movable range becomes difficult. There is a problem in that the installation location must be secured and the device itself becomes large, and that a highly accurate encoder becomes very expensive.

[0005]

According to a first aspect of the present invention, there is provided a first traveling body which holds a first optical system including a light source and a mirror, and a second optical system which includes a mirror group.
A second traveling body that is interlocked with the traveling body, and one of the first and second traveling bodies is directly driven by a motor with the traveling body as a main drive side, and the one traveling body and a plurality of movable bodies are movable. In the traveling body driving device of the image reading apparatus, the other traveling body connected via the pulley and the transmission means is driven to move in the sub-scanning direction at a speed ratio of 2: 1 to read the original image. A rotary encoder that generates an output signal for controlling the direct drive motor is arranged on one movable pulley.

According to a second aspect of the present invention, a first traveling body that holds a first optical system including a light source and a mirror, and a second traveling system that includes a second optical system including a mirror group are interlocked with the first traveling body. A traveling body, and one of the first or second traveling bodies is directly driven by a motor with the traveling body as one of the main driving sides, and the one traveling body, a plurality of movable pulleys, fixed pulleys, and transmission means. In the traveling body driving device of the image reading apparatus, which moves the sub-scanning direction at a speed ratio of 2: 1 by driving the other traveling body connected through the above-mentioned traveling body, the at least one fixed pulley is provided. A rotary encoder for generating an output signal for controlling the direct drive motor is arranged.

According to the invention of claim 3, claim 1 or 2
In the invention described above, rotary encoders having different resolutions are arranged on a plurality of movable pulleys or fixed pulleys, and these rotary encoders are selected and used.

According to the invention of claim 4, claim 1 or 2
In the invention described above, rotary encoders having the same resolution are arranged on a plurality of movable pulleys or fixed pulleys, and these rotary encoders are selected and used.

According to the invention of claim 5, claim 1 or 2
In the invention described above, a plurality of movable pulleys or fixed pulleys are arranged in a mixed manner with rotary encoders having the same resolution and rotary encoders having different resolutions, and the same or different rotary encoders are selected and used. .

According to a sixth aspect of the present invention, in the third, fourth or fifth aspect of the invention, a movable pulley provided on the same traveling body or image reading apparatus main body and on a line substantially parallel to the main scanning direction, or A traveling body movement information calculating means for calculating a motor feedback signal of traveling body speed and movement position information from an output signal of a rotary encoder installed on a fixed pulley is provided, and the calculated motor feedback signal and one side or both sides of the rotary encoder Motor feedback drive control means is provided for creating a motor drive control signal for driving and controlling the motor based on the information on the distance between the motor and the motor and the information on the distance between the rotary encoders.

According to the invention of claim 7, claim 1 or 2
In the invention described above, a traveling body movement information calculating means for calculating a motor feedback signal of the traveling body speed or movement position information from an output signal of a certain rotary encoder is provided, and the calculated motor feedback signal is used for the curvature of the guide rail. The motor feedback drive control that sets the rail curvature correction coefficient based on the above, and creates the motor drive control signal for driving and controlling the motor based on the motor feedback signal corrected by the set rail curvature correction coefficient. Means were provided.

According to an eighth aspect of the invention, in the invention of the seventh aspect, they are provided on the same running body or the image reading apparatus main body at the time of prescanning of the image reading apparatus and on a line substantially parallel to the main scanning direction. A pre-scan traveling body movement information calculation means for calculating a pre-scan motor feedback signal of traveling body speed and movement position information from an output signal of a rotary encoder installed on a movable pulley or a fixed pulley is provided, and the calculated pre-scan motor A radius-of-curvature determining means for determining the radius of curvature of the rail curvature correction coefficient from the feedback signal is provided.

[0013]

According to the first aspect of the present invention, the direct drive motor is controlled by using the output signal generated from the rotary encoder attached to the movable pulley, so that the expensive linear encoder has a wide range of installation locations. Since it is not necessary to use, the configuration can be made inexpensive and the installation location can be omitted.

According to the second aspect of the present invention, the harness connected to the rotary encoder is fixed by controlling the motor for direct drive by using the output signal generated from the rotary encoder attached to the fixed pulley. Therefore, the harness is not limited to a flexible material and its application can be expanded, and load fluctuation due to movement of the harness can be eliminated.
Further, this eliminates the need to use an expensive linear encoder having a wide range of installation places, and makes it possible to provide a configuration that is inexpensive and has a simplified installation place.

According to the third aspect of the present invention, by selecting and using the rotary encoders having different resolutions, it is possible to eliminate the generation of unused signals which are not used, and to perform the normal reading for low speed traveling and the prescan for high speed traveling. It is possible to create only the corresponding signals at the time of return and at the time of return.

According to the fourth aspect of the present invention, by selecting and using the rotary encoders having the same resolution, it is possible to prevent the usage from being concentrated on only one encoder and to prolong the life of the encoder. It will be possible.

According to the fifth aspect of the present invention, the rotary encoders having the same resolution and different resolutions are mixed and selected to be used, thereby eliminating the useless generation of an unused signal and at the time of normal reading at low speed. It becomes possible to create only the corresponding signals at the time of pre-scan or return that runs at high speed, and furthermore, the usage is not concentrated on only one encoder,
It is possible to extend the life of the encoder.

According to the sixth aspect of the present invention, the motor drive control signal is generated by using the motor feedback drive control means based on the motor feedback signal calculated by the travel body movement information calculation means. It is possible to perform accurate drive control of the motor in consideration of the speed and moving position of the motor.

According to the invention of claim 7, the motor feedback signal is corrected by the rail curvature correction coefficient,
By creating a motor drive control signal using the motor feedback drive control means based on this corrected motor feedback signal, the curvature of the guide rail can be corrected by a simple calculation. In addition, it becomes possible to perform accurate drive control of the motor in consideration of the curvature of the guide rail.

According to the invention of claim 8, the radius of curvature is determined by the radius of curvature determining means based on the prescan motor feedback signal which is the information from the prescanning traveling body movement information calculating means, and this radius of curvature is determined. Even if the curvature state of the guide rail is changed, a correct rail curvature correction coefficient is always obtained by creating a motor drive control signal using the motor feedback drive control means using the corrected rail curvature correction coefficient. This makes it possible to perform more accurate drive control of the motor than in the case of the invention of claim 7.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the invention described in claim 1 is shown in FIGS.
It will be described based on. Before entering the description of the configuration of the main part of the present embodiment, an outline of the configuration of the traveling body drive device will be described. First, the configuration of the scanning optical system will be described with reference to FIG.
A contact glass 2 on which an original (not shown) is set is provided on the upper surface of the main body 1, and a first optical system 5 including a halogen lamp 3 as a light source and a first mirror 4 is arranged on the lower surface of the contact glass 2. There is. The first optical system 5 includes a first traveling body 6
(See FIG. 1, which will be described later). A second optical system 9 including a mirror group of a second mirror 7 and a third mirror 8 is arranged at a position close to the first optical system 5. The second optical system 9 includes a second traveling body 10 (see FIG.
). As a result, the light from the halogen lamp 3 illuminates the document surface, and the reflected light is reflected by the first mirror 4, is condensed by the condenser lens 11 via the second and third mirrors 7 and 8, and is received. Element eg CCD
It is detected by the sensor 12. In this case, the image reading is
The entire area of the original image is read by scanning in the main scanning direction X by self-scanning of the CCD sensor 12 and scanning in the sub-scanning direction Y with a speed ratio of the first traveling body 6 and the second traveling body 10 of 2: 1. Can be read.

Next, the structure of the assembly portion of the first traveling body 6 and the second traveling body 10 will be mainly described with reference to FIG. First
A first guide rail 13 and a second guide rail 14 are arranged on both sides of the traveling body 6 in parallel with each other in the sub-scanning direction Y. The first traveling body 6 is fitted with two bearings 6a and 6b on the first guide rail 13 side,
The bearing 6c is in contact at one location on the second guide rail 14 side. In addition, the second traveling body 10 includes the first guide rail 13
Two bearings 10a and 10b are fitted on the side, and two bearings 10c and 10d are in contact on the second guide rail 14 side.

A movable back yoke 15 and a driving coil 16 are attached below the second traveling body 10, and an SN pole is provided on the main body 1 side facing the driving coil 16 with a constant gap. The magnets 17 are arranged in a state of being alternately arranged, and constitute a linear DC motor 18 as a motor for direct drive. As a result, when a current is passed through the drive coil 16 by a drive control circuit (not shown), the second traveling body 10 can be driven in the Y-direction by sub-scanning by direct drive. In addition, here, as a direct drive, a linear DC motor 18 (hereinafter,
The motor 18 is called as an example, but it is not limited to this as long as it is a direct drive type. Also, the first
Four bearings 6a, 6b, 1 that fit into the guide rail 13
As 0a and 10b, for example, a rolling bearing and a pressing member may be combined in addition to a sliding bearing in which a round bar and a round hole are combined.

Movable pulleys 19a and 19b are provided outside the first guide rail 13 of the second traveling body 10,
A first belt 20 (steel belt) as a transmission means is stretched between the movable pulleys 19a and 19b.
Similarly to this, the second guide rail 14 of the second traveling body 10
Movable pulleys 19c and 19d are provided on the outer side of, and a second belt 21 (steel belt) as a transmission means is stretched between these movable pulleys 19c and 19d. Further, the clamp portion 22a of the first traveling body 6 is clamped on the first belt 20 between the movable pulleys 19a and 19b, and the first belt 20 is clamped on the second belt 21 between the movable pulleys 19c and 19d.
The clamp portion 22b of the traveling body 6 is clamped.

3 (a) and 3 (b) show a state as viewed from the first belt 20 side. FIG. 3A shows the state at the reading scanning start position. The first belt 20 is fixed to the main body by the belt ends 23a and 23b at both ends thereof, and is wound around the movable pulleys 19a and 19b by half a turn. (Note that the second belt 21 side has the same configuration). Now, when the second traveling body 10 is directly driven by the motor 18 and is sub-scanning driven in the Ya direction from the state of the reading scanning start position, the operation of the first belt 20 and the two movable pulleys 19a and 19b causes The first traveling body 6 moves at a speed twice as fast as that of the second traveling body 10 to perform the reading operation. After that, when the reading scanning is completed, the first belt 20 and the two movable pulleys 19a, 1
9b stops at the reading scanning end position as shown in FIG. 3 (b). As a result, the movable pulley 19a is shown in FIG.
3 a from the position a _{1 to} the position a ₂ in FIG. 3B, the movable pulley 19 b moves from the position b ₁ in FIG.
This means that it has moved to the position b _{2 in} (b). The positions of the belt ends 23a and 23b do not change before and after the reading scan.

Next, the structure of the portion according to the present invention will be described with reference to FIG. In the present embodiment, in the traveling body drive device having the above-described configuration, a rotary encoder that generates an output signal for controlling the direct drive motor 18 is provided to at least one movable pulley (here, the movable pulley 19c). 24 are connected and provided. In this case, the rotary encoder 24 is composed of an encoder body 24a and a rotary shaft 24b at the center thereof. The encoder main body 24a is fixed to the end of the second traveling body 10 on the bearing 10c side, and the rotary shaft 24b at the center of the encoder main body 24a is the rotary shaft of the movable pulley 19c (same as the rotary shaft 24b). Therefore, the rotary shaft 24b and the movable pulley 19c have an integrated structure. A harness 25 for input / output signals (here, a flexible cable is used) is connected to the rotary encoder 24, and the harness 25 is bent downward in the main body at a position A and a control circuit is provided via a relay connector. (Not shown).

In such a structure, the second traveling body 10
Is driven by the motor 18 in the sub-scanning direction, the second belt 2
The movable pulley 19c is rotated by the action of 1, and the central rotary shaft 24b integrally formed with the movable pulley 19c is
Rotary encoder 2 fixed to the second traveling body 10
4 is rotated with respect to the encoder main body 24a. Due to such rotation, an output signal (not shown) corresponding to the rotation state of the movable pulley 19c is generated from the rotary encoder 24 and sent to the control circuit via the harness 25, so that the moving speed of the second traveling body 10 is increased. It is possible to obtain feedback information (that is, a feedback signal) such as the moving position and the moving position. Thus, the control voltage to the motor 18 provided below the second traveling body 10 can be determined based on the feedback information. As mentioned above,
Since the rotary encoder 24 is attached to the movable pulley 19c, it is not necessary to use an expensive linear encoder having a wide range of installation places as in the conventional case, and an inexpensive traveling unit drive device having an installation place is provided. be able to.

Next, an embodiment of the invention described in claim 2 will be described with reference to FIGS. 4 and 5. The description of the same parts as those of the embodiment of the invention described in claim 1 is omitted, and the same reference numerals are used for the same parts.

First, the overall structure of the traveling body drive system of FIG. 4 will be described. The configuration of the first traveling body 6 and the second traveling body 10 on the side of the first guide rail 13 and the method of hanging the first belt 20 are the same as those of the embodiment of the invention described in claim 1 (see FIG. 1). The description is omitted. Hereinafter, the configuration on the second guide rail 14 side and how to hang the second belt 21 will be described. On the second guide rail 14 side of the second traveling body 10,
Two movable pulleys 26a, 26b are provided, and turn pulleys 27a, 2 as fixed pulleys are provided on both sides thereof.
7b is provided on the main body 1 side. In addition, FIG.
(B) is a side view of the second belt 21 side. The second belt 21 has a belt end portion 28 at one end thereof.
The movable pulley 26a is fixed to the main body 1 by a, and then the turn pulley 27a is further half-turned, and then the turn pulley 27b at the opposite position is half-turned back again, and the movable pulley 26b is half-turned and the other end side is the belt end portion. It is fixed to the main body 1 at 28b. Further, the first traveling body 6 includes the clamp portion 22 between the movable pulley 26b and the turn pulley 27b.
It is fixed to the second belt 21 at b. FIG. 5A shows the state at the read scan start position, and FIG. 5B shows the state at the read scan end position after the second traveling body 10 is scanned in the Ya direction.

Next, the structure of the portion according to the present invention will be described. In the invention according to claim 1 (see FIG. 1) described above, the rotary encoder 24 is attached to the movable pulley 19c.
However, since the harness 25 connected to the rotary encoder 24 also moves in the sub-scanning direction Y during sub-scanning, it is necessary to use a flexible cable or the like as a harness material, which limits its use. Therefore, in the present embodiment, in consideration of such a point, in the traveling body drive device shown in FIG. 4, at least one fixed pulley (here, the turn pulley 27a) is for controlling the motor 18 for direct drive. A rotary encoder 29 for generating an output signal is arranged. In this case, the encoder body 29 of the rotary encoder 29
a is fixed to the main body 1 and has a rotating shaft 29b at the center thereof.
Is fixed to the center of the turn pulley 27a on the second belt 21 side via a coupling 30. As a result, the rotary shaft 29b and the turn pulley 27a have an integrated structure. In this case, the harness 31 for input / output signals is connected to the rotary encoder 29, but since the rotary encoder 29 is fixed to the main body 1, the harness 31
Is freely distributed and is connected to a control circuit (not shown) by following a free wiring path.

In such a structure, the second traveling body 10
Is driven by the motor 18 in the sub-scanning direction, the second belt 2
The turn pulley 27a is rotated by the action of No. 1 and the rotating shaft 29b is rotated with respect to the encoder body 29a fixed to the body 1 accordingly. This makes it possible to obtain feedback information such as the moving speed and the moving position of the second traveling body 10 from the output signal of the rotary encoder 29, and the motor 18 attached to the second traveling body 10 based on this feedback information. Drive voltage can be controlled.

As described above, the rotary encoder 29
Is attached to the turn pulley 27a fixed to the main body 1, the harness 31 connected to the rotary encoder 29 for sending an output signal can be fixed and freely wired, and the second traveling body 10 can be moved along with the movement. As a result, the harness 31 does not move. As a result, the harness 31 is not limited to a flexible one such as a flexible cable as in the invention of claim 1,
It is possible to greatly expand the uses, and it is also possible to eliminate obstacles such as load fluctuation due to harness movement. Further, since the output signal generated from the rotary encoder 29 is used to drive and control the motor 18 for direct drive, it is necessary to use an expensive linear encoder having a wide range of installation locations as in the embodiment of claim 1. Therefore, it is possible to obtain a traveling body moving device which is inexpensive and has a simplified installation place.

Next, an embodiment of the invention described in claim 3 will be described with reference to FIGS. 6 and 7. The description of the same parts as those of the embodiments of the invention described in claims 1 and 2 is omitted, and the same reference numerals are used for the same parts.

Generally, the traveling body driving device of the image reading apparatus is required to control the speed over a very wide range from a low speed during normal high-density reading to a high speed during prescan or return. For this reason, the encoder output is often divided and used, but at prescan and return, it is considerably faster than normal reading.Therefore, when division is performed, unnecessary signals that are not used are also created. Will be there. Therefore, in the present embodiment, in the traveling body drive apparatus according to the first and second aspects of the present invention, rotary encoders having different resolutions are arranged on a plurality of movable pulleys or fixed pulleys, and these rotary encoders are selected and used. It is the one. Hereinafter, a specific configuration example will be described with reference to FIGS. 6 and 7.

FIG. 6 shows an example in which the traveling body drive apparatus according to the first aspect of the present invention (see FIG. 1) is used. Here, the movable pulley 1 on the bearing 10d side of the second traveling body 10
A rotary encoder 32 having a resolution different from that of the rotary encoder 24 is attached to 9d. The encoder body 32a of the rotary encoder 32 is fixed to the second traveling body 10 side, and the rotary shaft 3 located substantially at the center thereof.
Since 2b is arranged so as to coincide with the rotating shaft of the movable pulley 19d, the rotating shaft 32b and the movable pulley 19d have an integral structure. A harness 33 for input / output signals is connected to such a rotary encoder 32. Here, a flexible cable is used as a harness material, and a relay connector that is bent downward at a position B and attached to the main body 1 is used. It is connected to a control circuit (not shown) via. As described above, the movable pulley 1
Rotary encoders 2 with different resolutions 9c and 19d
4 and 32 are installed, these rotary encoders 24 and 3
By selecting and using 2, it is possible to create only the signals corresponding to the low speed during normal reading and the high speed during pre-scanning and return, so that it is possible to avoid unnecessary signals that are not used and to be efficient. Circuit configuration.

FIG. 7 shows an example in which the traveling body drive apparatus according to the second aspect of the present invention (see FIG. 4) is used. Here, a rotary encoder 35 having a resolution different from that of the rotary encoder 29 is attached to the fixed pulley 27b of the second traveling body 10 via a coupling 34. Encoder body 35a of rotary encoder 35
Is fixed to the main body 1 side, and the rotation shaft 35b at the center thereof is
Is arranged so as to coincide with the rotating shaft of the fixed pulley 27b, the rotating shaft 35b and the fixed pulley 27b have an integral structure. Such a rotary encoder 3
A harness 36 for input / output signals is connected to 5,
Since the wiring is free here, it is connected to a control circuit (not shown) by following a free wiring path. Therefore, the harness material is not limited to the flexible cable. As described above, the fixed pulley 27
a and 27b are rotary encoders 29 having different resolutions,
By installing 35 and selecting and using these rotary encoders 29 and 35, only signals corresponding to low speed during normal reading and high speed during pre-scanning and returning can be created respectively, so they are not used. An unnecessary circuit is not created, and an efficient circuit configuration can be obtained.

Next, an embodiment of the invention described in claim 4 will be described with reference to FIGS. 8 and 9. The description of the same parts as those of the embodiments of the invention described in claims 1 to 3 will be omitted, and the same reference numerals will be used for the same parts.

In general, since the encoder is often installed integrally with the motor and the traveling body, it is very troublesome to replace it when the encoder fails. In particular, when a linear encoder is used, it is installed over the entire scanning range, so the difficulty of replacement work is not the ratio of the rotary encoder. Therefore, in the present embodiment, in the traveling body drive apparatus according to the first and second aspects of the present invention, rotary encoders having the same resolution are arranged on a plurality of movable pulleys or fixed pulleys, and these rotary encoders are selected and used. It was done like this. Hereinafter, a specific configuration example will be described with reference to FIGS. 8 and 9.

FIG. 8 shows an example in which the traveling body drive device according to the first aspect of the present invention (see FIG. 1) is used. Here, the movable pulley 1 on the bearing 10d side of the second traveling body 10
A rotary encoder 37 having the same resolution as the rotary encoder 24 is attached to 9d. The encoder main body portion 37a of the rotary encoder 37 is the second traveling body 1.
The rotation shaft 37 is fixed to the 0 side and is located at the center of the rotation shaft 37.
Since b is arranged so as to coincide with the rotary shaft of the movable pulley 19d, the rotary shaft 37b and the movable pulley 19d have an integral structure. A harness 38 for input / output signals is connected to such a rotary encoder 37. Here, a flexible cable is used as a harness material, and the harness 1 is bent downward at positions A and B.
Is connected to a control circuit (not shown) via a relay connector attached to the. As described above, the rotary encoders 2 having the same resolution are attached to the movable pulleys 19c and 19d.
4 and 37 are installed, and rotary encoders 24 and 3
By selecting and using 7, it is possible to prolong the life of each encoder, so that the replacement interval of the encoder can be made as long as possible and the working efficiency of the device can be improved.

FIG. 9 shows an example in which the traveling body drive apparatus according to the second aspect of the present invention (see FIG. 4) is used. Here, a rotary encoder 40 having the same resolution as the rotary encoder 29 is attached to the fixed pulley 27b of the second traveling body 10 via a coupling 39.
The encoder main body portion 40a of the rotary encoder 40 is fixed to the main body 1 side, and the rotation shaft 40b at the center thereof is arranged so as to coincide with the rotation shaft of the fixed pulley 27b. Therefore, the rotation shaft 40b and the fixed pulley 27b. And have an integrated structure. A harness 41 for input / output signals is connected to such a rotary encoder 40. Since the wiring is free here, it is connected to a control circuit (not shown) by following a free wiring path. The harness material is not limited to a flexible cable. As described above, by installing the rotary encoders 29, 40 having the same resolution on the fixed pulleys 27a, 27b and selecting and using these rotary encoders 29, 40, the life per encoder can be extended. The encoder replacement interval can be made as long as possible, and the work efficiency of the device can be improved.

Next, an embodiment of the invention described in claim 5 will be described with reference to FIGS. The description of the same parts as those of the embodiments of the invention described in claims 1 to 4 is omitted, and the same reference numerals are used for the same parts.

In the present embodiment, in the traveling body drive apparatus according to the first and second aspects of the present invention, a plurality of movable pulleys or fixed pulleys are mixed with rotary encoders having the same resolution and rotary encoders having different resolutions. The same or different rotary encoders are selected and used. FIG. 10 shows an example in which rotary encoders having the same resolution and different resolutions are mixedly installed on a plurality of movable pulleys, and FIG. 11 is a rotary encoder having the same resolutions and different resolutions are mixedly installed on a plurality of fixed pulleys. It shows an example of the case.

FIG. 10 shows an example in which the traveling body drive apparatus according to the fourth aspect of the present invention (see FIG. 8) is used.
Here, the rotary encoder 42 having a different resolution from the rotary encoders 24 and 37 is attached to the movable pulley 19a on the bearing 10a side of the second traveling body 10.
The encoder main body portion 42a of the rotary encoder 42 is fixed to the second traveling body 10 side, and the rotation shaft 42b substantially at the center thereof is arranged so as to coincide with the rotation shaft of the movable pulley 19a. 42b and the movable pulley 19a have an integral structure. A harness 43 for input / output signals is connected to such a rotary encoder 42. Here, a flexible cable is used as a harness material, and a relay connector which is bent downward at a position C and attached to the main body 1 is used. It is connected to a control circuit (not shown) via. As described above, the rotary encoders 24 and 37 having the same resolution are installed on the movable pulleys 19c and 19d, and the rotary encoders 42 having different resolutions from the rotary encoders 24 and 37 are installed on the movable pulley 19a. , 37, 42 are selected and used,
Only the signals corresponding to the low speed at the time of normal reading and the high speed at the time of pre-scanning and return are created respectively, and it is possible to make an efficient circuit configuration without creating unnecessary signals that are not used, and at the same time, the encoder 1 It is possible to prolong the life of each piece and to lengthen the encoder replacement interval as much as possible, thereby improving the working efficiency of the device. In addition,
Here, the rotary encoders 24 and 37 have the same resolution and the rotary encoder 42 has different resolution, but any combination may be used.

FIG. 11 shows an example in which the traveling body drive apparatus according to the fourth aspect of the present invention (see FIG. 9) is used.
Movable pulleys 44a and 44b are provided on the first guide rail 13 side of the second traveling body 10, and fixed pulleys 45a and 45b fixed to the main body 1 are provided on the outside thereof. The method of arranging the first belt 20 is as shown in FIG. 12, but since it can be considered as in the case of FIG. 5, the description thereof is omitted here. FIG. 12A shows the state at the read scan start position, and FIG. 12B shows the state at the read scan end position.

In this embodiment, a rotary encoder 47 having a resolution different from that of the rotary encoders 29 and 40 is attached to the fixed pulley 45a of the second traveling body 10 via a coupling 46. Rotary encoder 47
The encoder main body portion 47a is fixed to the main body 1 side, and the rotation shaft 47b at the center thereof is arranged so as to coincide with the rotation shaft of the fixed pulley 45a.
b and the fixed pulley 45a have an integrated structure. A harness 48 for input / output signals is connected to such a rotary encoder 47, and since the wiring is free here, it is connected to a control circuit (not shown) by following a free wiring path. The harness material is not limited to a flexible cable. As mentioned above,
The rotary encoders 29 and 40 having the same resolution are installed on the fixed pulleys 27a and 27b, and the fixed pulley 45a
A rotary encoder 47 having a resolution different from those of the rotary encoders 29, 40 is installed in the rotary encoders 29, 40, and the rotary encoders 29, 40, 47 are selected and used, so that a low speed during normal reading and a high speed during prescan or return can be achieved. It is possible to create an efficient circuit configuration by creating only the signals corresponding to each, and not creating unnecessary signals that are not used. Also, the life of each encoder is extended and the encoder replacement interval is as long as possible. The work efficiency of the device can be improved. Here, the rotary encoders 29 and 40 have the same resolution and the rotary encoder 47 has different resolution, but any combination thereof may be used.

Next, an embodiment of the invention described in claim 6 will be described with reference to FIGS. The description of the same parts as those of the embodiments of the invention described in claims 1 to 5 is omitted, and the same reference numerals are used for the same parts.

In the traveling body drive apparatus according to the invention described in claims 1 to 5, the position of each rotary encoder and the motor 1 are set.
The output signal from each rotary encoder does not represent an accurate signal for controlling the motor 18 because the position is different from the position shown in FIG. Therefore, the configuration of the apparatus in this embodiment is arranged as described below. As a specific example, FIG.
The apparatus of FIG. 14 will be described as an example.

FIG. 13 shows an example in which the traveling body driving device as shown in FIG. 10 is used. Here, the rotary encoders 24 and 42 are provided on the same second traveling body 10 and are arranged on a line substantially parallel to the main scanning direction X. It is desirable that the resolutions of the rotary encoders 24 and 42 are substantially equal, but they may be different. The rotary encoder 37 (see FIG. 10) on the movable pulley 19d side is omitted here. Further, the rotary encoders 24 and 42 may be similarly arranged on the movable pulleys 19c and 19d side of the second traveling body 10.

FIG. 14 shows an example in which the traveling body driving device as shown in FIG. 11 is used. Here, the rotary encoders 29 and 47 are provided on the same second traveling body 10 and are arranged on a line substantially parallel to the main scanning direction X. It is desirable that the rotary encoders 29 and 47 have substantially the same resolution, but they may have different resolutions. The rotary encoder 40 (see FIG. 11) on the fixed pulley 27b side is omitted here. Further, the rotary encoders 29 and 47 may be similarly arranged on the fixed pulleys 27b and 45b side of the second traveling body 10.

Next, the structure of various means for producing signals for controlling the motor 18 will be described. here,
The configuration of the control circuit will be mainly described. In the present embodiment, in the traveling body drive device of the invention according to claims 3 to 5 (here, as an example, the traveling body drive device of FIG. 13 or FIG. 14), the same traveling body or image reading device main body is used. Movable pulleys 19a, 1 provided on a line substantially parallel to the scanning direction X
9c or traveling body movement information calculating means for calculating a motor feedback signal Fb of traveling body speed or movement position information from output signals of rotary encoders 24, 42, 29, 47 installed on the fixed pulleys 27a, 45a. The calculated motor feedback signal and one or both rotary encoders 24, 42, 29, 47 and the motor 18
The distance b between the two rotary encoders 24, 42, 2
Motor feedback drive control means for generating a motor drive control signal Mc for controlling the drive of the motor 18 based on the distance a between 9 and 47 is provided.

FIG. 15 shows the construction of a control device provided with a traveling body movement information calculation means and a motor feedback drive control means. In the microcomputer 49, a microprocessor 50, a ROM 51, and a RAM
52 and 52 are connected via a bus 53. A command generator 53a that outputs a speed command signal for the motor 18 and the like is connected to the bus 53. The calculation result of the microcomputer 49 is sent to the drive interface device 54 via the bus 53. The drive interface device 54 generates a pulse signal (motor drive control signal Mc) for operating a drive device 55 including a power semiconductor such as a transistor. The voltage applied to the motor 18 is controlled by operating the drive device 55 based on the motor drive control signal Mc,
As a result, the motor 18 is driven at a desired speed to move the traveling body 56. Then, the speed of the motor 18 is determined by the rotary encoder (incremental encoder) 24.
After being detected by (29) and 42 (47), the output pulses are counted by a counter (not shown) provided inside by being sent to the interface devices 57 and 58 for state detection, whereby the speed and position are detected. A motor feedback signal Fb including information such as is detected. This motor feedback signal Fb is sent to the microcomputer 49 and subjected to arithmetic processing, and then a motor drive control signal Mc is created and sent to the drive device 55 side to control the voltage applied to the motor 18. Therefore, in FIG. 15, the rotary encoders 24 (29) and 42 (47) and the state detecting interface devices 57 and 58 constitute the traveling body movement information calculating means 59, and the motor feedback is provided inside the microcomputer 49. A drive control means (described later) is provided.

A method of detecting the speed of the motor 18 using the traveling body movement information calculation system 59 in such a control device is described by using the rotary encoders 24 (29) and 42 (47) to detect the speed and position and the position of the motor 18. The speed and position to be fed back will be taken into consideration. V ₁ indicates the speed by the rotary encoder 42 (47) on the first guide rail 13 side, and V ₂ indicates the speed by the rotary encoder 24 (29) on the second guide rail 14 side. Also,
V _L is the speed to be fed back in the motor 18. Now, the distance between the two rotary encoders 24 and 42 (or the rotary encoders 29 and 47) is a,
Rotary encoders 42, 4 on the first guide rail 13 side
The distance between 7 and the motor 18 is b. Since the traveling body can be regarded as one rigid body during the sub-scan, the rotary encoder 4 on the first guide rail 13 side.
Considering 2 (47) as a reference, the motion of the sub-scan can be modeled as shown in FIG. Here, from FIG. 16, the values such as the speed and the position of the motor 18 to be fed back are as follows: V _L = (b / a) × V ₂ + {(a−b) / a} × V ₁ (1) Become. Since (b / a) and {(ab) / a} are constants if the mechanical arrangement of the traveling body drive device is determined,
This calculation can be easily implemented in either digital or analog. Note that V ₁ and V ₂ are types of the motor feedback signal Fb.

Next, a method of calculating the speed ω (k) (= V ₁ , V ₂ ) by using the state detecting interface devices 57, 58 which constitute the traveling body movement information calculating system 59 will be described. The output terminal of the status detecting interface device 57 is connected to the interrupt terminal of the microprocessor 50, and the counter for counting the reference clock is provided inside the output terminal (for the status detecting interface device 58, see FIG. Is the same circuit, so its explanation is omitted). Now, in FIG. 17, the state immediately before the arrival of the edge 60 will be described. OB is an output pulse of the rotary encoder 24, and CLK is a reference clock of the state detecting interface device 57. The counter performs a decrement count from the count value (for example, 0FFFFH) given based on the CLK signal for the cycle of the OB pulse. When the edge 60 reaches the interrupt of the microprocessor 50, execution of an interrupt routine as shown in FIG. 18 is started. As a result, the decrement count value of the counter is latched by a storage register (not shown) built in the status detecting interface device 57 (P1). Next, the latched decrement count value is stored in the RAM 52 (P2). Next, an initial count value (0F for counting the pulse period of Tn
FFFH) is given, the decrement count is started again (P3), and the interrupt processing is ended. Then, when the edge 61 reaches the interrupt of the microprocessor 50 again, the processes of P1 to P3 in FIG. 18 are repeated. Therefore, the speed ω (k) obtained by using the state detection interface device 57 is as follows: speed ω (k) = k / (T _C × Ne × n) (2) where T _C : CLK cycle Ne: Incremental encoder division number per unit length n: CLK count number = 0FFFFH-decrement count number k: Unit conversion constant to speed. The velocity ω (k) thus obtained corresponds to the above-described general formula of the velocity V ₁ and V ₂ ,
It is a kind of the motor feedback signal Fb.

Next, the motor feedback signal Fb (V ₁ , V ₂ ) calculated from the equation (2) by the traveling body movement information calculation system 59 as described above and the motor speed V _L calculated from the equation (1). Based on the above, a method for controlling the drive of the motor 18 by creating the motor drive control signal Mc using the motor feedback drive control means will be described. FIG. 19
Shows a configuration of a motor feedback drive control system 62 as a motor feedback drive control means. Now, the rotary encoders 42 and 47 (see FIGS. 13 and 1)
The velocity V ₁ (i−1) detected by the above (4) is multiplied by the constant {(ab−b) / a} shown in the equation (1) in the block 63 and sent to the calculation unit 64. On the other hand, the velocity V ₂ (i-1) detected by the rotary encoders 24 and 29 (see FIGS. 13 and 14) is multiplied by the constant (b / a) shown in the equation (1) in the block 65, and the calculation unit Sent to 64.
The calculation unit 64 obtains the speed _VL (i-1) of the motor 18 as shown in the equation (1) from these two values. This speed V _L (i−1) is sent to the calculation unit 67 via the feedback loop 66. In the calculation unit 67, the control target value R (i) output from the command generator 53a,
The difference e (i) from the value from the feedback loop 66 is calculated. This difference e (i) is integrated in block 68,
In block 69, a constant Ki is multiplied and given to the arithmetic unit 70. Further, the difference e (i) is multiplied by the constant Kp in the block 71 and sent to the arithmetic unit 70. In the calculation unit 70, 2
The two inputs are added to obtain the control voltage V (i) to the motor 18 as the motor drive control signal Mc. As a result, the control voltage value V (i) is applied to the motor 18, the sub-scanning drive is performed, and the same loop processing is repeated. The control calculation in the motor feedback drive control system 62 is performed by the microcomputer 49.
It can be easily realized because it is performed by the numerical calculation processing in the above. Although the digital PI control has been described as an example of the control method, analog control or PI control is used.
It can be performed by D control or even modern control.

As described above, the movable pulleys 19a, 19c (19b, 19d) or the fixed pulleys 27a, 45a (27b) provided on the same traveling body 10 or main body 1 and on a line substantially parallel to the main scanning direction X. , 45b), the output signals of the rotary encoders 24, 42 (29, 47) installed in the traveling body movement information calculation system (traveling body movement information calculating means) 59 are calculated. Based on the motor feedback signal Fb, the motor feedback drive control system (motor feedback drive control means) 62 is used to generate the motor drive control signal Mc, so that the speed and the movement position of the traveling body 10 are accurately considered. The drive control of the motor 18 can be performed.

Next, an embodiment of the invention described in claim 7 will be described with reference to FIGS. The description of the same parts as those of the embodiments of the invention described in claims 1 to 6 is omitted, and the same reference numerals are used for the same parts.

Generally, in the traveling body drive device, it is desirable to make the guide rails 13 and 14 completely parallel to the sub-scanning direction Y, but it is almost impossible in reality, and the guide rails 13 and 14 themselves have a curvature. It is normal to put it away. If the guide rails 13 and 14 have a curvature, the position of the rotary encoder (not shown) and the position of the motor 18 are different, so the output signal from the encoder is not a signal for performing accurate control of the motor 18. Not not. In view of this, in the present embodiment, in the traveling body drive device according to the first and second aspects of the invention, traveling body movement information for calculating a motor feedback signal of traveling body speed or movement position information from an output signal of a certain rotary encoder. Provide a calculation means,
To set the rail curvature correction coefficient that corrects the calculated motor feedback signal based on the curvature of the guide rail, and to control the drive of the motor based on the motor feedback signal corrected by this set rail curvature correction coefficient. The motor feedback drive control means for generating the motor drive control signal is provided. 20
The configuration of the control device is shown and is the same as that of the control device of FIG. Further, the configuration of the traveling body movement information calculation means for calculating the motor feedback signal Fb (speed, movement position, etc.) is the same as that of the traveling body movement information calculation system 59 (see FIG. 15) described above, and the description thereof will be omitted. . The rail curvature correction coefficient and the configuration of the motor feedback drive control means will be sequentially described below.

First, a method of obtaining the rail curvature correction coefficient will be described with reference to FIG. Generally, even if the guide rail has a curvature, its value is quite small, and the motion of the traveling body is a rotary motion, but each point on the rail can be approximately regarded as a translational motion. In consideration of such points, the case where the traveling body shown in FIG. 10 is used will be described as an example. Now, the traveling body has a radius of curvature r around the point O in the bearing 10a of the second guide rail 13 of the second traveling body 10.
Let's say you are in a rotating motion. Bearing 10c and second traveling body 1
The distance between the rotary encoder 42 attached to the first guide rail 13 and the rotary encoder 42 is 0, and the distance between the central portion of the motor 18 and the rotary encoder 42 is d.
V ₁₁ is a value (motor feedback signal Fb) such as speed and position by the rotary encoder 42, V ₁₂ is a value such as speed and position (motor feedback signal Fb) at the bearing 10c, and V _L is in the motor 18. These are values such as speed and position to be fed back (motor feedback signal Fb). Since the traveling body can be regarded as one rigid body during the sub-scan, V ₁₂ on the bearing 10c side can be expressed as V ₁₂ = {r / (r−c)} × V ₁₁ (3). Therefore, the value V _L to be fed back motor 18 parts, V _L = [{(c-d) / c } + (d / c) × {r / (r-c)} ] × V ₁₁ = {( It can be expressed as r−c + d) / (r−c)} × V ₁₁ (4). From such a relational expression, the radius of curvature r of the guide rail can be mechanically measured before assembly. Here, if D = {(r-c + d) / (r-c)} (5) is set, D is a constant (hereinafter referred to as a rail curvature correction coefficient) determined only by the mechanical arrangement of the traveling body drive device. Call)
And can be calculated using a simple calculation formula.

Next, a method for controlling the drive of the motor 18 by using the rail curvature correction coefficient D thus obtained to generate the motor drive control signal Mc by the motor feedback drive control means will be described. FIG. 22 shows the configuration of the motor feedback drive control system 72 as the motor feedback drive control means. Now, the velocity V ₁₁ (i-1) detected by a certain rotary encoder 42 (see FIG. 10) is multiplied by the rail curvature correction coefficient D given by the equation (5), and thereby the equation (4) is obtained. _VL (i-1) of the motor 18 as shown in FIG. Then, the velocity V _L (i-
The value of 1) is passed through the feedback loop 66 and the calculation unit 6
Send to 7. After that, the same control calculation processing as the motor feedback drive control system 62 of FIG. 19 is performed to obtain the control voltage V (i) which is the motor drive control signal Mc. By applying the control voltage V (i) thus obtained to the motor 18, the sub-scanning drive is performed, and the same loop processing is repeated again. Since all the control calculation in the motor feedback drive control system 72 is performed by the numerical calculation processing in the microcomputer 49, it can be easily realized. As a control method,
Although the digital PI control has been described as an example, it can be performed by analog control, PID control, or even modern control. Further, in the present embodiment, the rotary encoder of the traveling body in FIG. 10 is used for description, but the present invention is not limited to this, and other traveling bodies (for example, FIGS. 1 and 4) may be used.

As described above, the motor feedback signal Fb (V ₁₁ ) obtained from a certain output is multiplied by the preset rail curvature correction coefficient D for correction, and the motor feedback signal Fb (V _L ) is obtained. By creating the motor drive control signal Mc using the motor feedback drive control system 62 based on the motor feedback signal V _L , the curvature of the guide rail can be corrected by a simple calculation process, which allows the vehicle to travel. It is possible to perform accurate motor drive control in consideration of not only the body speed and movement position but also the curvature of the guide rail.

Next, an embodiment of the present invention will be described with reference to FIGS. 23 to 25. The description of the same parts as those of the embodiments of the invention described in claims 1 to 7 is omitted, and the same reference numerals are used for the same parts.

In the invention described in claim 7, since the rail curvature correction coefficient D is set in advance, there is a possibility that erroneous control will be performed when the state of the controlled object changes. . Therefore, in the present embodiment, in the traveling body drive apparatus according to the invention of claim 7, the traveling body drive apparatus is provided on the same traveling body or image reading apparatus main body at the time of prescanning of the image reading apparatus and on a line substantially parallel to the main scanning direction X. The pre-scanning traveling body movement information calculating means for calculating the pre-scanning motor feedback signal PFb of the traveling body speed and movement position information from the output signal of the rotary encoder installed on the movable pulley or the fixed pulley is provided and calculated. A radius-of-curvature determining means for determining the radius-of-curvature r of the rail curvature correction coefficient D from the pre-scan motor feedback signal PFb is provided. Here, the configuration of the motor feedback drive control means for generating the motor drive control signal Mc during the normal image reading, not during the prescan, is the same as that of the motor feedback drive control system 72 (see FIG. 22) described above, and therefore the description thereof will be omitted. Will be omitted. Hereinafter, the configurations of the prescan traveling body movement information calculating means for calculating the prescan motor feedback signal PFb during the prescan and the curvature radius determining means for determining the curvature radius r of the rail curvature correction coefficient D will be mainly described.

First, the overall flow of image reading is shown in FIG.
It will be described based on the flowchart of FIG. When the start button or the like is pressed to start reading by the image reading device, it is first determined whether or not the prescan mode is set (Q
1). This can be realized, for example, by setting a button or a signal for setting whether or not to perform pre-scanning before reading in the image reading apparatus. Next, if it is determined to be in the pre-scan mode, in the pre-scan traveling body movement information calculation system 73 (see FIG. 24 described later) as the pre-scan traveling body movement information calculation means, the traveling body drive device performs the sub-scanning. It is driven, and the prescan motor feedback signal PFb is calculated by this (Q2). Next, in the curvature radius determining unit 74 (see FIG. 25 described later) as the curvature radius determining means, the calculated pre-scan motor feedback signal P
The radius of curvature r is determined based on Fb and written in the RAM 52 (Q3). Then, it is again determined whether the pre-scan mode is set, and when it is determined that the normal image reading mode is set, the motor feedback drive control system 7
2 (see FIG. 22), the traveling body is subjected to sub-scanning drive control (Q4), and an image is read (Q5). In this case, at the time of image reading, the value of the radius of curvature r used in the rail curvature correction coefficient D of FIG. 22 can be the value of the radius of curvature r determined by the radius of curvature determining unit 74, which allows the value immediately before the image is read. Since the radius of curvature r in the state can be used, accurate drive control can always be performed even when the state changes.

Next, the operation of the prescan traveling body movement information calculation system 73 during prescan will be described with reference to FIG. The speed V (i-1) detected by the rotary encoder (for example, the rotary encoders 24 and 42 in FIG. 13 or the rotary encoders 29 and 47 in FIG. 14) is
It is sent to the calculation unit 67 via the feedback loop 75. After that, the same control calculation processing as the motor feedback drive control system 62 of FIG. 19 is performed to obtain the control voltage V (i) which is the motor drive control signal Mc. The sub-scanning drive is performed by applying the control voltage V (i) thus obtained to the motor 18, and the same loop processing is repeated again. Therefore, by performing the prescan by the prescan traveling body movement information calculation system 73, it is possible to calculate the prescan motor feedback signal PFb of the information on the traveling body speed and movement position. Since all the control calculation in the pre-scan traveling body movement information calculation system 73 is performed by the numerical calculation processing in the microcomputer 49, it can be easily realized. Although the digital PI control has been described as an example of the control method, analog control, PID control, or even modern control can be used.

Next, the radius of curvature r is determined by the radius of curvature determining unit 74 based on the prescan motor feedback signal PFb of the information on the speed and the moving position of the traveling body obtained by performing the prescan in this way. A method for doing so will be described with reference to FIGS. Figure 25 (a)
Indicates that the position of α indicates the sub-scanning start position and the position of β indicates the sub-scanning end position. From such a relationship, the rotary encoder (for example, the rotary encoders 24 and 4 in FIG.
2 or the value of the position output (distance between before and after scanning) of the rotary encoder 29, 47 in FIG. 14 is inclined by θ due to the rail curvature, and thus shows different values like S ₁ and S ₂ . Therefore, now, if the distance between two rotary encoder disposed parallel to the main scanning direction X and a, the radius of curvature r _{is, r = {S 2 / (} S 2 -S 1)} × a ... ( 6) can be obtained by a simple calculation formula. The position measurement by the rotary encoder (incremental encoder) can be easily realized by the microcomputer 49 (see FIG. 15) by counting the number of pulses of the incremental encoder which has a one-to-one relationship with the moving position. You can

Further, in FIG. 25B, a rotary encoder (for example, the rotary encoder 24,
42, or the rotary encoder 29, 47 of FIG. 14)
V speed output (or average value of several speed outputs)
When _1, V _2, the radius of curvature r may be determined as _{r = {V 2 / (V} 2 -V 1)} × a ... (7). When performing normal image reading, the value of the radius of curvature r determined by the equations (6) and (7) is substituted into the equation (5) to obtain the rail curvature correction coefficient D. Then, the rail curvature correction coefficient D calculated from the radius of curvature r is used to perform motor drive control in the motor feedback drive control system 72 shown in FIG. 22 to change the curvature state immediately before the image is read. However, accurate drive control can always be performed.

As described above, the radius of curvature r is determined by the radius of curvature determining section 74 based on the prescan motor feedback signal PFb which is the information from the prescan traveling body movement information calculation system 73, and this radius of curvature r is By creating the motor drive control signal Mc using the motor feedback drive control system 72 using the determined rail curvature correction coefficient D, even when the curvature state of the guide rail changes, the rail curvature correction is always accurate. It is possible to obtain the coefficient D, which makes it possible to perform more accurate drive control of the motor than in the case of the invention described in claim 7.

[0068]

According to the first aspect of the present invention, the first traveling body that holds the first optical system including the light source and the mirror and the second optical system that includes the mirror group are interlocked with the first traveling body. A second traveling body is provided, and either one of the first traveling body and the second traveling body is directly driven by a motor with one traveling body as a main drive side, and the one traveling body, a plurality of movable pulleys, and transmission means are provided. In the traveling body driving device of the image reading device, which moves the sub-scanning direction at a speed ratio of 2: 1 by driving the other traveling body connected via the sub-scanning body, the at least one movable pulley is Since the rotary encoder that generates the output signal for controlling the motor for the direct drive is arranged, it is not necessary to use an expensive linear encoder having a wide installation place, It is possible to provide a device which is omitted of space encoder arranged in valence.

According to a second aspect of the present invention, a first traveling body that holds a first optical system including a light source and a mirror and a second traveling system that holds a second optical system including a mirror group are interlocked with the first traveling body.
A traveling body, and one of the first or second traveling bodies is directly driven by a motor with the traveling body as one of the main driving sides, and the one traveling body, a plurality of movable pulleys, fixed pulleys, and transmission means. In the traveling body driving device of the image reading apparatus, which moves the sub-scanning direction at a speed ratio of 2: 1 by driving the other traveling body connected through the above-mentioned traveling body, the at least one fixed pulley is provided. Since the rotary encoder that generates the output signal for controlling the motor for the direct drive is arranged, the harness is fixed and the load fluctuation due to the movement of the harness can be eliminated, and the wiring can be freely distributed, and the harness can be used. The material can be expanded. In addition, this eliminates the need for an expensive linear encoder having a wide range of installation locations, and it is possible to provide an inexpensive apparatus in which a space for arranging the encoder is omitted.

According to a third aspect of the invention, in the first or second aspect of the invention, rotary encoders having different resolutions are arranged on a plurality of movable pulleys or fixed pulleys, and these rotary encoders are selected and used. Therefore, it is possible to provide an efficient circuit configuration in which only signals corresponding to normal reading for low-speed traveling and pre-scan for high-speed traveling or return are generated, and unnecessary signals are not generated.

According to a fourth aspect of the invention, in the first or second aspect of the invention, rotary encoders having the same resolution are arranged on a plurality of movable pulleys or fixed pulleys, and these rotary encoders are selected and used. Therefore, the use is not concentrated on only one encoder, the replacement interval of the encoder can be made as long as possible, and the life of the encoder can be extended.

According to a fifth aspect of the present invention, in the first or second aspect of the invention, a plurality of movable pulleys or fixed pulleys are arranged in a mixture of a rotary encoder having the same resolution and a rotary encoder having a different resolution. However, since the same or different rotary encoders are selected and used, it is a useless signal that only the corresponding signals are created at the time of normal reading for low-speed traveling and at the time of pre-scan or return for high-speed traveling. It is possible to provide an efficient circuit configuration in which the encoder is not created, and the usage is not concentrated on only one encoder, the replacement interval of the encoder can be made as long as possible, and the life of the encoder can be extended.

According to a sixth aspect of the present invention, in the third, fourth or fifth aspect of the present invention, a movable pulley provided on the same running body or image reading apparatus main body and on a line substantially parallel to the main scanning direction, or A traveling body movement information calculating means for calculating a motor feedback signal of traveling body speed and movement position information from an output signal of a rotary encoder installed on a fixed pulley is provided, and the calculated motor feedback signal and one side or both sides of the rotary encoder Since the motor feedback drive control means for creating a motor drive control signal for driving and controlling the motor is provided based on the information on the distance between the motor and the motor and the information on the distance between the rotary encoders, It is possible to perform accurate feedback control of the motor in consideration of the speed and moving position of the motor.

According to a seventh aspect of the present invention, in the first or second aspect of the present invention, a traveling body movement information calculation is performed which calculates a motor feedback signal of traveling body speed and movement position information from an output signal of a certain rotary encoder. Means is provided, and a rail curvature correction coefficient for correcting the calculated motor feedback signal based on the curvature of the guide rail is set, and the motor is corrected based on the motor feedback signal corrected by the set rail curvature correction coefficient. Since the motor feedback drive control means for creating a motor drive control signal for drive control is provided, the curvature of the guide rail can be corrected by a simple calculation, and not only the speed and moving position of the traveling body but also the curvature of the guide rail can be calculated. It is possible to perform more accurate feedback control of the motor in consideration.

According to an eighth aspect of the invention, in the invention according to the seventh aspect, the image forming apparatus is provided on the same running body or the image reading apparatus main body at the time of prescanning and on a line substantially parallel to the main scanning direction. A pre-scan traveling body movement information calculation means for calculating a pre-scan motor feedback signal of traveling body speed and movement position information from an output signal of a rotary encoder installed on a movable pulley or a fixed pulley is provided, and the calculated pre-scan motor Since the radius of curvature determining means for determining the radius of curvature of the rail curvature correction coefficient from the feedback signal is provided, an accurate rail curvature correction coefficient can always be obtained even when the curvature state of the guide rail changes. Performing more accurate feedback control of the motor than in the case of the invention of claim 7. It can be.

[Brief description of drawings]

FIG. 1 is a plan view showing a configuration example of a traveling body drive device according to a first aspect of the invention.

FIG. 2 is a side view showing a configuration example of an image reading apparatus.

FIG. 3 is a side view showing a state before and after a traveling belt is moved.

FIG. 4 is a plan view showing a configuration example of a traveling body drive device according to a second aspect of the invention.

FIG. 5 is a side view showing a state before and after movement of the traveling belt.

FIG. 6 is a plan view showing a configuration example of a traveling body drive device according to a third aspect of the invention.

FIG. 7 is a plan view showing another configuration example of the traveling body drive device.

FIG. 8 is a plan view showing a configuration example of a traveling body drive device according to a fourth aspect of the invention.

FIG. 9 is a plan view showing another configuration example of the traveling body drive device.

FIG. 10 is a plan view showing a configuration example of a traveling body drive apparatus according to a fifth aspect of the invention.

FIG. 11 is a plan view showing another configuration example of the traveling body drive device.

FIG. 12 is a side view showing a state before and after movement of the traveling belt.

FIG. 13 is a plan view showing a configuration example of a traveling body drive device according to a sixth aspect of the invention.

FIG. 14 is a plan view showing another configuration example of the traveling body drive device.

FIG. 15 is a block diagram showing a configuration example of a control device.

FIG. 16 is a schematic diagram showing a relationship such as speed and position of a rotary encoder and a motor.

FIG. 17 is a timing chart illustrating a speed detection method.

FIG. 18 is a flowchart of interrupt processing.

FIG. 19 is a block diagram of a motor control system.

FIG. 20 is a block diagram showing a configuration example of a control device according to a seventh aspect of the invention.

FIG. 21 is a schematic diagram showing the relationship between the speed and position of a rotary encoder and a motor.

FIG. 22 is a block diagram of a motor control system.

FIG. 23 is a flowchart showing an example of a reading operation of the image reading device according to the invention of claim 8;

FIG. 24 is a block diagram of a motor control system.

25A is a schematic diagram showing a sub-scanning start position and a sub-scanning end position of the traveling body, and FIG. 25B is a schematic diagram showing a speed relationship of the rotary encoder.

[Explanation of symbols]

3 Light source 4 Mirror 5 1st optical system 6 1st traveling body 9 2nd optical system 10 2nd traveling body 18 Motors 19a-19d Movable pulley 20,21 Transmission means 24 Rotary encoder 26a, 26b Movable pulley 27a, 27b Fixed pulley 29 , 32, 35, 37, 40, 42, 47, 49
Rotary encoder 59 Traveling body movement information calculating means 62, 72 Motor feedback drive control means 73 Prescan traveling body movement information calculating means 74 Curvature radius determining means Fb Motor feedback signal PFb Prescan motor feedback signal Mc Motor drive control signal D Rail curvature correction Coefficient Y Sub-scanning direction

Claims (8)

[Claims] 1. A first traveling body that holds a first optical system including a light source and a mirror, and a second traveling body that holds a second optical system including a mirror group and that interlocks with the first traveling body, One of the first and second traveling bodies is used as a main drive side for direct drive by a motor, and the other traveling body is connected to the one traveling body via a plurality of movable pulleys and transmission means. By following the body, 2
In a moving body driving device of an image reading device that reads a document image by moving in the sub-scanning direction at a speed ratio of 1: 1, an output signal for controlling the direct drive motor is generated at the at least one movable pulley. A traveling body drive device in which a rotary encoder is arranged. 2. A first traveling body that holds a first optical system including a light source and a mirror, and a second traveling body that holds a second optical system including a mirror group and that interlocks with the first traveling body, One of the first and second traveling bodies is directly driven by a motor with one traveling body as a main drive side, and is connected to the one traveling body through a plurality of movable pulleys, fixed pulleys and transmission means. In the traveling body driving device of the image reading apparatus, which drives the other traveling body to move in the sub-scanning direction at a speed ratio of 2: 1 to read the original image, the at least one fixed pulley is provided with the direct drive. A traveling body drive device comprising a rotary encoder for generating an output signal for controlling a motor. 3. The traveling body drive apparatus according to claim 1, wherein rotary encoders having different resolutions are arranged on a plurality of movable pulleys or fixed pulleys, and these rotary encoders are selected and used. 4. The traveling body drive apparatus according to claim 1, wherein rotary encoders having the same resolution are arranged on a plurality of movable pulleys or fixed pulleys, and these rotary encoders are selected and used. 5. A rotary encoder having the same resolution and a rotary encoder having different resolutions are mixedly arranged on a plurality of movable pulleys or fixed pulleys, and the same or different rotary encoders are selected and used. The traveling body drive device according to claim 1 or 2. 6. The speed and movement of the traveling body based on the output signal of a rotary encoder installed on a movable pulley or a fixed pulley provided on the same traveling body or the main body of the image reading apparatus and on a line substantially parallel to the main scanning direction. A traveling body movement information calculation means for calculating a motor feedback signal of position information is provided, and the calculated motor feedback signal, information on the distance between the rotary encoders on one side or both sides and the motor, and information on the distance between both rotary encoders. 6. The traveling body drive apparatus according to claim 3, further comprising a motor feedback drive control means for generating a motor drive control signal for driving and controlling the motor based on the above. 7. A traveling body movement information calculating means for calculating a motor feedback signal of traveling body speed and movement position information from an output signal of a certain rotary encoder is provided, and the calculated motor feedback signal is used for the curvature of the guide rail. The motor feedback drive control that sets the rail curvature correction coefficient based on the above, and creates the motor drive control signal for driving and controlling the motor based on the motor feedback signal corrected by the set rail curvature correction coefficient. 3. The traveling body drive device according to claim 1, further comprising means. 8. An output signal of a rotary encoder installed in a movable pulley or a fixed pulley provided on the same traveling body or main body of the image reading device and on a line substantially parallel to the main scanning direction during prescanning of the image reading device. A pre-scanning traveling body movement information calculating means for calculating a pre-scanning motor feedback signal of traveling body speed and movement position information from the 8. The traveling body drive apparatus according to claim 7, further comprising radius determining means.