JP2003266848A - Method for correcting speed error of moving body - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a method for correcting the speed error of a moving body which makes the moving speed of the moving body approximately constant, by accurately correcting variation in the moving speed of the moving body caused by the lead pitch nonuniformity of a ball screw and can control occurrence of visible image nonuniformity. <P>SOLUTION: A standard position in the rotational direction of a shaft 204 is determined, and the error of a feed quantity of a recording head 37 corresponding to at least one rotation of the shaft 204 by the constant speed driving of a pulse motor 206 is measured. Correction data for correcting the speed error of the recording head 37 during at least one rotation of the shaft 204 based on the error of the feed quantity every prescribed rotational angle of the shaft from the standard position or every prescribed time are stored in a memory 262. When the shaft 204 is practically rotated by constant speed driving, the correction data are read out by one by one from the memory 262 on the basis of the standard position to correct the driving speed of the pulse motor 206. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention corrects the drive speed of the drive source when the ball screw connected to a moving body is actually driven to rotate by constant speed drive of the ball screw. By doing so, the present invention relates to a method for correcting a speed error of a moving body, which corrects a speed error (moving speed fluctuation) of the moving body.

[0002]

2. Description of the Related Art A sheet-shaped recording material, particularly a printing plate having a photosensitive layer provided on a support, is used while being rotated at a high speed while being wound around a peripheral surface of a rotating drum (main scanning). ), A technique for recording an image directly on the photosensitive layer (emulsion surface) of the printing plate with a laser beam or the like by moving a moving body (recording head) in the axial direction of the rotating drum (sub scanning) has been developed. (Printing plate exposure device). With such a technique, it is possible to quickly record an image on a printing plate.

Here, a ball screw is used to move the recording head. The ball screw includes
A pulse motor is connected as a drive source for rotating the ball screw by inputting a pulse. By inputting a pulse of a constant cycle to the pulse motor, the drive source is driven at a constant speed, and the ball screw is driven to rotate.

[0004]

However, depending on the accuracy of the position of the groove formed in the ball screw (manufacturing accuracy), that is, the lead pitch unevenness, an error in the feed amount for one rotation of the ball screw occurs. I will end up. When the feed amount error occurs, the moving speed of the recording head fluctuates, and so-called misregistration occurs when forming an image. For this reason, visible image unevenness appears on the formed image.

[0005]

SUMMARY OF THE INVENTION In consideration of the above facts, the present invention corrects the moving speed fluctuation of the moving body due to the unevenness of the lead pitch of the ball screw more accurately than the conventional one, so that the moving speed of the moving body is substantially reduced. An object of the present invention is to provide a method for correcting a velocity error of a moving body that can be kept constant and that can suppress the occurrence of visible image unevenness.

[0006]

According to a first aspect of the present invention, a reference position in a rotation direction of a ball screw connected to a moving body is determined, and a constant speed of a drive source for rotationally driving the ball screw. A feed amount error of the moving body corresponding to at least one rotation of the ball screw due to driving is measured, and a speed error of the moving body during at least one rotation of the ball screw based on the feed amount error of the moving body is measured. Correction data for correcting a predetermined rotation angle of the ball screw from the reference position or a predetermined time is stored in a memory of a control unit that controls the drive source, and the drive source performs constant-speed drive. When the ball screw is actually rotationally driven, the control unit sequentially reads the correction data from the memory based on the reference position and corrects the drive speed of the drive source. It is characterized by correcting the speed error of the moving object.

According to the first aspect of the invention, the measuring means for measuring the accuracy of the position of the groove formed in the ball screw is used. For example, a linear measuring optical system that measures the accuracy using a laser beam is used as the measuring means. Here, in order to measure the accuracy, a reference position in the rotation direction of the ball screw is determined in advance. At least one of the ball screws is measured by measuring the accuracy while driving the driving source that rotationally drives the ball screw at a constant speed.
The feed amount error for the rotation is measured. Further, in order to correct the speed error during at least one rotation of the ball screw based on the feed amount error for at least one rotation, a memory is used as a storage unit that stores correction data for correcting the speed error. To be Here, the correction data stored in the memory is data for correcting the speed error at every predetermined rotation angle of the ball screw from the reference position or every predetermined time. Further, when the ball screw is actually rotationally driven by the driving source at a constant speed, the correction data is sequentially read from the memory and the reference set when the feed amount error for at least one rotation is measured. A control unit is used as a control unit that corrects the drive speed of the drive source based on the position. With this, by correcting the moving speed fluctuation of the moving body due to the unevenness of the lead pitch of the ball screw more accurately than before,
The moving speed of the moving body can be made substantially constant, and the occurrence of visible image unevenness can be suppressed.

According to a second aspect of the present invention, in the invention of the first aspect, the period of the pulse for driving the drive source is changed when the drive speed of the drive source is corrected. It has a feature.

According to the second aspect of the present invention, the drive speed of the drive source is corrected by changing the period of the pulse for driving the drive source, and the speed error is made smaller than before correction. You can

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a printing plate automatic exposure apparatus 10 according to this embodiment.

The printing plate automatic exposure device 10 is provided with a printing plate 1.
It is divided into two blocks: an exposure unit 14 that exposes an image by irradiating the two image forming layers with a light beam, and a transport guide unit 18 that transports the printing plate 12 to the exposure unit 14. The printing plate 12 exposed by the printing plate automatic exposure device 10 is sent to a developing device (not shown) installed adjacent to the printing plate automatic exposure device 10.

The exposure unit 14 is mainly composed of a rotary drum 16 for winding and holding the printing plate 12 on its peripheral surface, and the printing plate 12 is guided by a conveyance guide unit 18 to be rotated. It is designed to be fed in from the tangential direction. The transport guide unit 18 includes a plate supply guide 20 and a plate discharge guide 22.

A plate feed guide 20 of the transport guide unit 18
The relative positional relationship between the plate discharge guide 22 and the plate discharge guide 22 is a horizontal V-shape, and is configured to rotate a predetermined angle around the center of FIG. By this rotation, the plate feeding guide 2
0 or the plate discharge guide 22 is selectively associated with the rotary drum 16 (arranged in the tangential direction of the rotary drum 16).
be able to.

In addition, a punching machine 24 for punching a through hole serving as a reference for winding the printing plate 12 around a plate cylinder of a rotary press (not shown) is provided near the transport guide unit 18, By allowing the plate guide 20 to face the punching machine 24, the leading edge of the printing plate 12 can be fed to the punching machine 24. That is, the printing plate 12
First, the sheet is guided by the plate feed guide 20 and fed into the punching machine 24. After punching, for example, a circular hole and a long hole at the tip of the printing plate 12, the sheet is once returned to the plate feed guide 20. After that, by rotating the transport guide unit 18, the printing plate 12 is moved to a position corresponding to the rotary drum 16.

FIG. 2 shows the transport guide unit 18 in a state where the plate discharge guide 22 is removed (that is, only the plate supply guide 20 is attached).

A pair of pusher units 66 are provided at the end of the plate feed guide 20 opposite to the rotary drum 16 (the end on the front side in FIG. 2).

The pusher unit 66 is composed of a pressing portion 68 provided on the surface (upper surface) of the plate feeding guide and a support shaft (not shown) for rotatably supporting the pressing portion 68. The shaft penetrates a pair of slit holes 20A provided in the plate supply guide 20 and penetrates to the back surface (lower surface) side of the plate supply guide 20.

Next, corresponding to the pusher unit 66, a pair of positioning pins 74 capable of projecting and retracting with respect to the surface of the plate feeding guide 20 are provided at the end of the plate feeding guide 20 on the rotary drum 16 side. There is.

The positioning pin 74 can be provided at two positions, that is, a projecting position that projects above the surface of the plate feeding guide 20 and a retracted position that retracts below the surface of the plate feeding guide 20.

A widthwise pusher unit 84 movable along the axial direction of the rotary drum 16 is provided at one widthwise end of the plate feed guide 20 (left end in FIG. 2).

The width direction pusher unit 84 includes a pressing portion 86 provided on the surface (upper surface) of the plate feed guide and a support shaft (not shown) for rotatably supporting the pressing portion 86.
The support shaft penetrates the slit hole 20B provided in the plate feeding guide 20 and penetrates to the back surface (lower surface) side of the plate feeding guide 20.

As shown in FIG. 2, the slit hole 20B.
Are extended in the axial direction of the rotary drum 16. As a result, the width direction pusher unit 84 can move along the slit hole 20B of the plate feed guide 20 in parallel to the axial direction of the rotary drum 16.

On the other hand, as shown in FIG. 2, the plate feed guide 2
A pair of positioning pin units 92 movable along the axial direction of the rotary drum 16 are provided at the other widthwise end portion of 0 (the right end portion in FIG. 2).

The positioning pin unit 92 is provided with a positioning pin 94 provided on the surface (upper surface) of the plate feed guide 20.
And a support shaft that rotatably supports the positioning pin 94.
(Not shown), the support shaft passes through a pair of slit holes 20C provided in the plate feed guide 20 and penetrates to the back surface (lower surface) side of the plate feed guide 20.

As shown in FIG. 2, slit hole 20C
Are parallel to each other and extend in the axial direction of the rotary drum 16. As a result, the positioning pin unit 94
Can be moved in parallel with the axial direction of the rotary drum 16 along the slit holes 20C of the plate feed guide 20, and are arranged at the positioning position in advance depending on the size of the printing plate 12.

The rotating drum 16 is driven by a driving means (not shown) to expose the printing plate 12 in the mounting exposure direction (direction of arrow A in FIG. 1) and in the removal direction of the printing plate 12 opposite to the mounting exposure direction (arrow B in FIG. 1). Direction).

As shown in FIG. 1, a tip chuck 26 is attached to the rotary drum 16 provided in the exposure unit 14 at a predetermined position on the outer peripheral surface. Exposure unit 14
Then, when the printing plate 12 is mounted on the rotary drum 16, first, the tip chuck 26 is moved by the transport guide unit 1
Rotating drum 1 at a position (printing plate mounting position) facing the front end of printing plate 12 fed by plate feeding guide 20
Stop 6

The exposure section 22 is provided with a mounting cam 28 facing the tip chuck 26 at the printing plate mounting position.
The tip chuck 26 can insert the printing plate 12 between itself and the peripheral surface of the rotating drum 16 by rotating the mounting cam 28 and pressing one end side thereof.

In the exposure section 14, with the front end of the printing plate 12 inserted between the front end chuck 26 and the rotary drum 16, the mounting cam 28 is returned to release the pressure on the front end chuck 26, and the printing plate 12 is released. The tip of 12 is clamped and held between the tip chuck 26 and the peripheral surface of the rotary drum 16.

At this time, the printing plate 12 is in contact with a pair of positioning pins 100 and 102, the tip surfaces of which project at predetermined positions on the peripheral surface of the rotary drum 16, and the width direction of the printing plate 12 is abutted. One end of the rotary drum 16 comes into contact with a positioning pin 104 projecting from one end of the rotary drum 16 in the axial direction, and is finally positioned with respect to the rotary drum 16.

In the exposure unit 14, when the front end of the printing plate 12 is fixed to the rotary drum 16, the rotary drum 16 is rotated in the mounting exposure direction. As a result, the transport guide unit 18
The printing plate 12 fed from the plate feeding guide 20 is wound around the peripheral surface of the rotating drum 16.

In the vicinity of the peripheral surface of the rotary drum 16, the squeeze roller 3 is located downstream of the printing plate mounting position in the mounting exposure direction.
0 is placed. The squeeze roller 30 moves toward the rotary drum 16 to move the rotary drum 16.
The printing plate 12 wound on the rotary drum 16 is pressed against the rotating drum 16 to bring the printing plate 12 into close contact with the peripheral surface of the rotating drum 16.

The exposure unit 14 has a squeeze roller 3
A trailing edge chuck attachment / detachment unit 32 is arranged near the downstream side of the rotation exposure direction of the rotary drum 16 with respect to zero. A rear end chuck 36 is attached to the rear end chuck attachment / detachment unit 32 at the tip of a shaft 34 protruding toward the rotary drum 16.

In the exposure section 14, the trailing edge of the printing plate 12 wound around the rotating drum 16 is the trailing edge chuck attaching / detaching unit 3
When facing 2, the shaft 34 is projected and the rear end chuck 36 is mounted at a predetermined position on the rotary drum 16. As a result, the trailing edge chuck 36 holds and holds the trailing edge of the printing plate 12 with the rotating drum 16.

In the exposure section 14, when the front end and the rear end of the printing plate 12 are held by the rotating drum 16, the squeeze roller 30
Separate. After that, in the exposure unit 14, the rotary drum 1
While rotating 6 at a predetermined rotation speed at high speed, the recording head 37 irradiates a light beam modulated based on image data in synchronization with the rotation of the rotating drum 16. As a result, the printing plate 12 is scanned and exposed based on the image data.

In the exposure unit 14, when the scanning exposure of the printing plate 12 is completed, the rotary drum 16 is moved to a position where the rear end chuck 36 holding the rear end of the printing plate 12 faces the rear end chuck attaching / detaching unit 32. Pause the rotating drum 16
Then, the rear end chuck 36 is removed. As a result, the trailing edge of the printing plate 12 is opened.

After that, by rotating the rotary drum 16 in the take-out direction of the printing plate 12, the printing plate 12 is discharged from the rear end side to the plate discharge guide 22 of the transport guide unit 18 along the tangential direction of the rotary drum 16. After that, it is conveyed to the developing device in the next step.

FIG. 4 shows a control system for rotating the rotary drum 16, moving the recording head 37, and recording an image by the recording head 37 based on an image signal.

The rotary drum 16 is rotated by the driving force of the servo boat 200. The rotation speed of the servo motor 200 is controlled based on the drive signal from the controller 258.

Further, the recording head 37 is moved in the axial direction of the rotary drum 16 by axially rotating the shaft 204 on which the male screw of the ball screw mechanism is formed by the pulse motor 206.

A rotary encoder 250 is attached to one side of the rotary shaft 16A of the rotary drum 16. The rotary encoder 250 includes the rotary drum 16
A pulse signal is output in accordance with the rotation of, and this reference position signal is input to the 1 / M frequency dividing circuit 252.

The 1 / M frequency dividing circuit 252 divides the input pulse signal by 1 / M to generate a PLL (Phase Locked
Loop) circuit 254. This PLL circuit 254
Then, the 1 / M frequency-divided pulse signal is fed back through the 1 / N frequency dividing circuit 256, so that the pulse signal is controlled to match the 1 / N frequency-divided pulse signal in phase. As a result, the input 1 is input from the PLL circuit 254.
A pulse signal obtained by adding (N / M) to the pulse signal divided by / M is output as an image writing clock pulse signal.

That is, for example, when the pulse signal from the rotary encoder 250 is 60 KHz and the controller 258 sets the M value to 60 and the N value to 30,000, the PLL circuit 254 writes the 30 MHz image clock. A pulse signal will be output.

The image writing clock pulse signal output from the PLL circuit 254 is input to the frequency correction circuit 260 provided in the controller 258.

The frequency correction circuit 260 corrects the image writing clock pulse signal based on the correction data stored in the memory 262, and the head controller 266.
To a true image writing clock pulse signal.

Further, in the above-mentioned servo motor 200,
A servo controller 268 for controlling the servo motor 200 is connected, and the servo controller 268 operates according to an instruction from the controller 258.

Further, in the above-mentioned pulse motor 206,
A pulse generation circuit 270 that generates a pulse signal for driving the pulse motor 206 is connected.

Further, the pulse generation circuit 270 includes
A CPU circuit 272 for controlling the pulse generation circuit 270 is connected. The CPU circuit 272 has a memory 274 storing correction data for correcting a feed amount error of at least one rotation of the shaft 204.
The correction data is read from the memory 274 and the pulse generation circuit 270 is controlled according to the instruction from the controller 258 described above.

An oscillator 276 for generating a clock for generating a pulse signal for driving the above-mentioned pulse motor 206 is connected to the pulse generating circuit 270.

In the pulse generation circuit 270 described above, the clock from the oscillator 276 is frequency-divided and the pulse motor 2 is operated.
A pulse signal for driving 06 is generated, and the frequency division ratio L of the clock is the above-mentioned CPU circuit 27.
2 is set.

The drive speed of the pulse motor 206 described above is controlled based on the pulse signal from the pulse generation circuit 270. The cycle of the pulse signal input to the pulse motor 206 is changed by the CPU circuit 272, so that the drive speed is changed.

The correction data stored in the memory 274 is
The shaft 2 of the ball screw mechanism is mounted by a highly accurate measuring device (not shown) after the assembly is completed for each device in advance.
The correction accuracy (production accuracy) of the position where the male screw No. 04 is formed, that is, the correction data based on the lead pitch unevenness or the like is stored for each address of the image data.

As shown in FIG. 5 (A), when the shaft 204 is rotated at a constant speed, the lead pitch unevenness changes every rotation of the shaft 204. In the present embodiment, ideally, a groove is formed in the shaft 204 so that the recording head 37 moves by 10 mm in the sub-scanning direction for one rotation of the shaft.

Here, when measuring the manufacturing accuracy,
For example, a linear measuring optical system that measures the manufacturing accuracy by using a laser beam may be used as the measuring device. Further, in order to measure the manufacturing accuracy, a reference position in the rotation direction of the shaft 204 is determined in advance.
A pulse motor 206 that rotationally drives the shaft 204.
By measuring the manufacturing accuracy while driving at a constant speed,
A feed error of at least one revolution of the shaft 204 is measured. The correction data stored in the memory 274 is data for correcting the speed error during at least one rotation of the ball screw based on the feed amount error for at least one rotation.

The pulse motor 206 is adapted to rotate by an amount corresponding to the number of input pulses. Therefore, the shaft 204 rotates in response to the rotation of the pulse motor 206, and the speed error of the recording head 37 is corrected.

In this embodiment, the pulse cycle is changed by instructing the pulse generation circuit 270 to change the frequency division ratio L from the CPU circuit 272.

Here, in this embodiment, when the pulse motor 206 receives 30,000 pulses, the shaft 204 makes one rotation. The recording head 37 moves in response to the rotation of the shaft 204. When the time required for this is set to 500 ms, the frequency of the pulse needs to be 60 kHz. At this time, if the clock frequency from the oscillator 276 is 30 MHz, the division ratio L is set to 500.

When the frequency division ratio is set to 501, it takes 501 ms to move the recording head 37 in response to the rotation of the shaft 204. Similarly, divide by 4
When set to 99, it takes 499 ms for the recording head 37 to move in response to the rotation of the shaft 204.

As described above, the moving speed of the recording head 37 can be adjusted by sequentially switching the frequency division ratio L set in the pulse generation circuit 270 from the CPU circuit 272.

When the speed adjustment is performed at intervals of about 1 mm of moving distance using the correction data relating to the change of the pulse period described above, when the speed error is corrected as shown in FIG. 5 (B). It can be seen that the lead pitch unevenness during one revolution of the shaft 204 is substantially equal to zero. As a result, the moving speed fluctuation of the recording head due to the uneven lead pitch of the shaft 204 can be corrected more accurately than before, so that the moving speed of the recording head can be made substantially constant, and the occurrence of visible image unevenness can be suppressed. be able to.

The head controller 266 controls the recording head 37 to irradiate the printing plate 12 with a light beam modulated based on the input image data, to rotate the rotary drum 16 (main scanning), and to record. An image is recorded on the printing plate 12 by the movement (sub-scanning) of the head 37.

The operation of this embodiment will be described below.

First, the measurement of the lead pitch unevenness due to the position of the groove formed on the shaft 204 using a measuring device will be described.

When measuring the lead pitch unevenness,
The pulse motor 206 is driven at a constant speed. While driving the pulse motor 206 at the constant speed, the shaft 204 is rotated from a reference position in the rotation direction of the shaft 204. Here, the lead pitch unevenness is measured using a measuring device such as a linear measuring optical system.

By measuring the lead pitch unevenness, the feed amount error of at least one rotation of the shaft 204 is measured.

Correction data for correcting the speed error during at least one rotation of the ball screw based on the feed amount measurement error is created, and the correction data is stored in the memory 274.

Next, a case where an image is actually formed using the correction data will be described.

When the shaft 204 is rotated by driving the pulse motor 206 and the recording head 37 is moved in the sub-scanning direction, the CPU circuit 272 sequentially reads the correction data stored in the memory 274,
The frequency division ratio L of the pulse generation circuit 270 is changed (set) based on the correction data.

The pulse whose cycle is changed by the change is output from the pulse generation circuit 270 to the pulse motor 206.

Since the rotation angle of the pulse motor 206 is determined by the number of input pulses, the rotation speed of the pulse motor 206 is changed when the pulse cycle is changed.

By changing the rotation speed of the pulse motor 206, the rotation speed of the shaft 204 is changed.

By changing the rotational speed of the shaft 204, the moving speed of the recording head 37 connected to the shaft 204 is changed.

Here, FIG. 6A shows movement data of the relationship between time and distance of the recording head 37 measured by a measuring device such as a linear measuring optical system. Figure 6
The movement data shown in (A) looks linear. However, actually, as shown in FIG. 6 (B), an error occurs in the movement data shown in FIG. 6 (A) with respect to the ideal movement of the recording head 37 having no lead pitch unevenness. When the movement data shown in FIG. 6B is expanded in the time axis direction, a runout having a cycle corresponding to one rotation of the ball screw appears.

When the horizontal axis of the graph shown in FIG. 6B is converted into the moving distance of the recording head 37 and is regarded as a sine wave,
It becomes like the graph shown in FIG. When the rotational speed of the shaft 204 is corrected based on the correction data stored in the memory 274 with respect to the state shown in FIG. 5A, the graph shown in FIG. And the error is in the range of 8um to 0.5u
It can be seen that it has decreased to m.

As described above, in the present embodiment,
By correcting the moving speed fluctuation of the recording head 37 due to uneven lead pitch of the shaft 204 of the ball screw mechanism more accurately than before, the moving speed of the recording head 37 can be made substantially constant, and visible image unevenness can be obtained. Can be suppressed.

In the present embodiment, the frequency division ratio L in the pulse generation circuit 270 is the reference frequency division ratio 500, and the frequency division ratios 499 and 501 when the frequency division ratio is changed.
However, it is not limited to this. The frequency division ratio that can be set according to the lead pitch unevenness may be set so that visible image unevenness does not occur.

[0077]

As described above, according to the present invention, it is possible to make the moving speed of the moving body substantially constant by correcting the moving speed fluctuation of the moving body due to the unevenness of the lead pitch of the ball screw more accurately than before. Therefore, it has an excellent effect that the occurrence of visible image unevenness can be suppressed.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a printing plate automatic exposure apparatus according to the present embodiment.

FIG. 2 is a perspective view of a transport guide unit when a plate discharge guide is removed (printing plate temporary positioning state).

FIG. 3 is a perspective view of the transport guide unit when a plate discharge guide is removed (printing plate book positioning state).

FIG. 4 is a block diagram showing a control system for image recording control.

5A is a graph showing a moving distance error of the recording head due to lead pitch unevenness when the shaft of the ball screw mechanism is rotated at a constant speed, and FIG. 5B is a correction based on the lead pitch unevenness. 6 is a graph showing a moving distance error of the recording head when the rotational speed of the shaft is corrected according to data.

FIG. 6A is a graph showing movement data of the relationship between time and distance of the recording head measured by a measuring device such as an optical system for linear measurement, and FIG. 6B is a graph in FIG.
6 is a graph showing an error of movement data with respect to an ideal movement of a recording head having no lead pitch unevenness.

[Explanation of symbols] 37 recording head 204 shaft 206 pulse motor 270 pulse generator 272 CPU circuit 274 memory 276 oscillator

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F16H 25/20 F term (reference) 2C162 AE23 AE28 AE48 AF13 AF82 FA04 FA17 2C480 CA11 DA28 EA02 2H084 AE08 3J062 AA35 AA36 AB22 AC07 BA14 CD22

Claims (2)

[Claims] 1. A reference position in the rotational direction of a ball screw connected to a moving body is determined in advance and corresponds to at least one rotation of the ball screw driven at a constant speed by a drive source that rotationally drives the ball screw. A feed amount error of the moving body is measured, and a speed error of the moving body during at least one rotation of the ball screw based on the feed amount error of the moving body is calculated as a predetermined rotation of the ball screw from the reference position. Correction data for correcting each angle or every predetermined time is stored in a memory of a control unit that controls the drive source, and when the ball screw is actually rotationally driven by the drive source at a constant speed, the control unit is controlled. However, the speed error of the moving body is corrected by sequentially reading the correction data from the memory based on the reference position and correcting the drive speed of the drive source. Speed error correction method of the moving body that. 2. When correcting the drive speed of the drive source,
The method for correcting a velocity error of a moving body according to claim 1, wherein a period of a pulse for driving the drive source is changed.