JP3047876B2 - Driving apparatus and driving method for disk-shaped recording medium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving apparatus and a driving method for a disk-shaped recording medium, and more particularly to control of rotation of a disk-shaped recording medium such as an optical disk.

[0002]

2. Description of the Related Art Optical disks such as CDs (compact disks) and DVDs (digital video disks) are known as portable information recording media. In such an optical disc, information including address information is generally spirally recorded at a constant linear velocity. Among such optical discs, a CD has a unit channel bit length T (= 1/1).
4.3218 MHz), and the data group consists of 3T (shortest pulse) to 11T (longest pulse), and one frame is composed of 588T.

FIG. 2 is a block diagram showing the configuration of a conventional optical disk device having such optical disk characteristics. In this optical disk device, the shortest / longest pulse detector 34 detects the shortest or longest pulse read from the optical disk 31 by the optical head of the pickup 32 supplied via the preamplifier 33. The pseudo synchronizing signal generator 35 generates a pseudo synchronizing signal based on the detected shortest pulse or longest pulse.
7

On the other hand, a synchronization signal detector 36 detects a synchronization signal from information read from the optical disk 31 by the optical head of the pickup 32 supplied via the amplifier 33 and supplies the synchronization signal to the changeover switch 37. Then, the changeover switch 37 is switched in accordance with the synchronization signal detected by the synchronization signal detector 36, and the output signal from the changeover switch 37 is converted into an fV converter 38, a phase comparator 39, and an adder.
The rotation is supplied to the disk motor 42 via the amplifier 40 and the amplifier 40, and the rotation of the disk motor 42 is controlled.

[0005]

However, in the above-mentioned conventional optical disk device, the shortest / longest pulse detector 3 is used.
4 indicates that the optical head of the pickup 32 is
The shortest pulse or the longest pulse could not be detected until the position corresponding to the target address (target position) was reached. Therefore, the rotation frequency of the disk motor 42 (optical disk 31) cannot be controlled only after the optical head of the pickup 32 is moved,
It took time to access the information of the target address.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and shortens the time required for a disk-shaped recording medium to reach a specified rotational frequency.
It is an object of the present invention to provide a drive apparatus and a drive method for a disk-shaped recording medium that can reduce the time required for accessing a desired address.

[0007]

According to a first aspect of the present invention, there is provided a drive apparatus for a disk-shaped recording medium in which information including address information is spirally recorded at a constant linear velocity. A driving unit for driving the disk-shaped recording medium, wherein the driving unit is configured to rotationally drive the disk-shaped recording medium, and is movable in a radial direction of the disk-shaped recording medium, and is rotationally driven by the driving unit. Reading means for reading information recorded on the disk-shaped recording medium, address information extracting means for extracting first address information from the information read by the reading means, Address information acquiring means for acquiring second address information corresponding to the desired information, and the second information acquired by the address information acquiring means. Moving means for moving the reading means to a position on the disc-shaped recording medium corresponding to an address; and a moving means for reading information corresponding to the second address information acquired by the address information acquiring means. A frequency calculating means for calculating a target rotation frequency of the disk-shaped recording medium based on the second address information and a recording state of the information on the disk-shaped recording medium;
Frequency detecting means for detecting a rotation frequency, and the driving means
And a control means for controlling the rotation drive of the disk-shaped recording medium by said control means, said moving means before
The second address acquired by the address information acquiring means.
At a position on the disc-shaped recording medium corresponding to the information.
If the reading means is not moved, the address information extraction
On the basis of the first address information extracted by the output means.
First control means for controlling the motion means, said moving means before
The second address acquired by the address information acquiring means.
At a position on the disc-shaped recording medium corresponding to the information.
When moving the reading means, the frequency detecting means
The detected rotation frequency is the value calculated by the frequency calculation means.
Until the target rotation frequency becomes equal to the target rotation frequency.
The drive is performed so that the disc-shaped recording medium is rotationally driven.
Second control means for controlling the means, and the second control means
Target rotation frequency calculated from the rotation frequency detected by
When it is equal to, the drive by the first control means
And third control means for shifting to control of the moving means . Note that the control by the first control means is
This is the case when information recorded on a disc-shaped recording medium is
Information is being read continuously.
In this case, the second address information is externally
Not input, readout means by the second address information
There is no movement. When control is performed by the second control means
Indicates that the second address information is input and the input second
When moving the reading means based on the address information
is there. The third control means includes, for example, second address information
Control only when there is a movement of the reading means due to
Means switch to control the drive means, otherwise
In such a case, switch the first control means to control the driving means.
It can be configured with a switch to be replaced.

[0008] In the above-mentioned apparatus for driving a disk-shaped recording medium, the second control means can control the driving means in parallel with the movement of the reading means by the moving means.

[0009] In the drive device for the disk-shaped recording medium,
The rotation frequency of the disc-shaped recording medium can be controlled in parallel with the movement of the reading means for reading the information recorded on the disc-shaped recording medium. Therefore, the time required to access a desired address of the disk-shaped recording medium is reduced.

[0010] The drive device for the disk-shaped recording medium may further include frequency comparison means for comparing the target rotation frequency calculated by the frequency calculation means with the rotation frequency detected by the frequency detector. . In this case, the second control means can control the rotational drive of the disk-shaped recording medium by the drive means according to the comparison result by the frequency comparison means.

[0011] In the drive device for the disk-shaped recording medium, the address information obtained by the address information obtaining means is t, the maximum radius of the disk-shaped recording medium is R, and the track pitch of the recorded information is p. Means for calculating a radius r from the center of the disk-shaped recording medium to which the reading means is to be moved by the moving means when the linear velocity of the information is V. Can be.

R = 場合 (R ² + (pV / π) × t) In this case, the frequency calculating means includes: a circumference 2πr at a radius r which is a moving position of the moving means; The target rotation frequency can be calculated from the linear velocity V of the information recorded in the above.

In order to achieve the above object, a method for driving a disk-shaped recording medium according to a second aspect of the present invention is a method for driving a disk-shaped recording medium in which information including address information is spirally recorded at a constant linear velocity. Driven by a motor,
A method for driving a disc-shaped recording medium for reading information from a disc-shaped recording medium that is rotationally driven by a reader that is movable in a radial direction of the disc-shaped recording medium, comprising: Address information extracting step of extracting the address information of the above, address information obtaining step of obtaining second address information corresponding to desired information recorded on the disk-shaped recording medium, and address information obtaining step of obtaining the address information. Moving the reader to a position corresponding to the second address, and the disc when the reader reads information corresponding to the second address information acquired in the address information acquiring step. The target rotation speed of the disk-shaped recording medium is determined by the second address information and the disk-shaped recording medium. A frequency calculating step of calculating, based on the recording state of information to the disc-shaped recording medium
Alternatively, a frequency detection switch for detecting the rotation frequency of the motor
Step and the second address from the moving step
Before the position on the disk-shaped recording medium corresponding to the information
If there is no movement of the reader, the address information extraction
Based on the first address information extracted in step
A first control step of controlling a motor;
The directory corresponding to the second address information by the
The reader is moved to a position on the disk-shaped recording medium
If the rotation frequency detected in the frequency detection step is
With the target rotation frequency calculated in the frequency calculation step
Until it becomes difficult to record the disk shape at the target rotation frequency.
A second controlling the motor so that the recording medium is driven to rotate;
Control step and the second control step
Target calculated by the rotation frequency detected by motor control
When the rotation frequency becomes equal to the rotation frequency, the first control step is performed.
A third control step for shifting to control of the motor by
And a tip . In addition, the first to third
The control step means that the disk
The first to third control means in the recording medium driving device
Each corresponds.

In the method for driving a disk-shaped recording medium, the second control step may control the motor in parallel with the movement of the reader in the moving step.

In the above-described method for driving a disk-shaped recording medium,
The rotation frequency of the disk-shaped recording medium can be controlled in parallel with the movement of the reader for reading the information recorded on the disk-shaped recording medium. Therefore, the time required to access a desired address of the disk-shaped recording medium is reduced.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block diagram showing the configuration of an optical disk device according to this embodiment. This optical disk device reads information recorded on an optical disk 1. As shown, a pickup 2, a preamplifier 3, a digital signal processor 4, an arithmetic unit 5, a controller 6, a target Rotation speed setting device 7, disk motor 8, frequency detector 9, frequency comparator 10, synchronization signal detector 11, changeover switch 12, phase comparator 13
, An fV converter 14, an adder 15, and an amplifier 16.

On the optical disc 1, information including address information is spirally recorded at a constant linear velocity, and each bit of the information is represented as "0" or "1" by a finely processed hole.
Is shown. The optical disc 1 includes types such as a CD (compact disc), a DVD (digital video disc), and an LD (laser disc). For example, in the case of a CD, information is recorded as follows. (1) Information is recorded from the inner circumference to the outer circumference from a position where the radius from the center of the disk is 25 mm to a position where the radius is 58 mm. The track pitch is 1.6 μm. (2) The unit channel bit length is T (= 1 / 4.321)
(8 MHz), the data group consists of 3T to 11T, and 588T constitutes one frame.

The pickup 2 has an optical head for irradiating the optical disk 2 with a laser beam and reading the reflected light reflected by a fine hole corresponding to a bit of information recorded on the optical disk 2. Pickup 2
Converts the reflected light read by the optical head into an electric signal according to the intensity thereof, and supplies the electric signal to the preamplifier 3. The pickup 2 has a linear motor that moves the optical head in the radial direction of the optical disc 1 according to the spiral of the recorded information, and moves the optical head to a position determined as described later when a target address is given. Can be

The preamplifier 3 amplifies an electric signal corresponding to information recorded on the optical disk 2 supplied from the pickup 2 and supplies the amplified electric signal to the digital signal processor 4 and the synchronization signal detector 11.

The digital signal processor 4 extracts address information from the information read from the optical disk 2 supplied in the form of an electric signal from the amplifier 3 and supplies it to the controller 6 as a current address.

The arithmetic unit 5 includes, from the target address supplied from the controller 6, a position at which the optical head of the pickup 2 corresponding to the target address is to be moved, and a disk motor 8 for reading information from the position on the optical disk 1. The target rotation frequency of (optical disc 1) is obtained as follows.

Assuming that the outer radius of the optical disc 1 is R, the track pitch is p, and the linear velocity is V, the relationship between the radius r of the position of the optical head of the pickup 2 from the center of the disc and the target address t is shown in Equation 3. It becomes something.

Vt = π (r ² −R ² ) / p

From Equation 3, the radius r indicating the position of the optical head is given by Equation 4.

R = √ (R ² + (pV / π) × t) The circumference of the optical disc 1 at this position is 2πr ,
From the circumference 2πr and the linear velocity V, a target rotation frequency is obtained. The calculation device 5 supplies the target rotation frequency obtained as described above to the target frequency setting device 7 as a calculation result.

The controller 6 calculates a target address to which the optical head of the pickup 2 is to be moved based on information input from the outside such as the order of music pieces recorded on the optical disk 1 and supplies the target address to the arithmetic unit 5. . Controller 6
Supplies a changeover signal for changing over the changeover switch 12 to the changeover switch 12 as described later, based on the current address supplied from the digital signal processor 4 and the calculated target address.

The target frequency setting device 7 includes a buffer for storing a target rotation frequency which is a calculation result of the calculation device 5,
The target rotation frequency stored in the buffer is supplied to the frequency comparator 10.

The disk motor 8 rotates the optical disk 1. The rotation frequency of the disk motor 8, that is, the rotation frequency of the optical disk 1, is controlled by the amplifier 1 as described later.
6 is controlled in accordance with the signal supplied from.

The frequency detector 9 detects the rotation frequency of the disk motor 8, that is, the rotation frequency of the optical disk 1, and supplies it to the frequency comparator 10.

The frequency comparator 10 includes a target frequency setting device 7
Is compared with the rotation frequency detected by the frequency detector 9. The frequency comparator 10 supplies frequency information for setting the rotation frequency of the disk motor 8 when the optical head of the pickup 2 moves to the target rotation frequency to the changeover switch 12 based on the comparison result.

The synchronization signal detector 11 detects a synchronization signal from a signal supplied from the preamplifier 3 and converted from information recorded on the optical disk 1.

The changeover switch 12 is switched to one of the frequency comparator 10 and the synchronization signal detector 11 in accordance with a switching signal supplied from the controller 6. Depending on the switching state, either the frequency information or the synchronization signal is changed. And supplies it to the phase comparator 13 and the fV converter 14.

The phase comparator 13 compensates for the phase of the synchronous signal detected by the synchronous signal detector 11 supplied via the selector switch 12 when the switch 12 is switched to the synchronous signal detector 12 side. Then, it is supplied to the adder 15.

When the changeover switch 12 is switched to the frequency comparator 10 side, the fV converter 14 converts the frequency information supplied through the changeover switch 12 into a voltage signal, and outputs the voltage signal. To supply.

The adder 15 adds the signal from the phase comparator 13 and the signal from the fV converter 14 and outputs the result.
However, when the changeover switch 12 is switched to the synchronization signal detector 11 side, there is substantially no signal from the fV converter 14, and in this case, the adder 15 outputs the phase output from the phase comparator 13. And outputs the compensated synchronization signal.
On the other hand, when the changeover switch 12 is switched to the frequency comparator 10 side, there is substantially no signal from the phase comparator 13, and in this case, the adder 15 converts the voltage signal from the fV converter 14 Output.

The amplifier 16 amplifies the output signal from the adder 15 and supplies it to the disk motor 8. The output signal from the amplifier 16 is a signal for controlling the rotation frequency of the disk motor 8.

The operation of the optical disk device according to this embodiment will be described below. First, a steady state operation of continuously reading information recorded on the magnetic disk 1 will be described. In this case, the controller 6 switches the changeover switch 12 to the synchronization signal detector 11 by the changeover signal. Then, the synchronization signal detected by the synchronization signal detector 11 is supplied to the disk motor 8 via the changeover switch 12, the phase comparator 13, the adder 15, and the amplifier 16. The disk motor 8 is rotated at a rotation frequency controlled according to a supplied synchronization signal (actually, an amplified synchronization signal) to rotate the optical disk 1, and in response to the rotation, the optical head of the pickup 1. Is also moved.

Next, an operation in the case where information such as the order of music pieces is input to the controller 6 from outside will be described. First, the controller 6 switches the changeover switch 12 to the frequency comparator 10 by a changeover signal in response to input of information from outside. Also, the controller 6
Based on information input from the outside, a target address to which the optical head of the pickup 2 should be moved is calculated and supplied to the arithmetic unit 5.

In accordance with the calculated target address, the moving position of the optical head of the pickup 2 and the disc motor 8
The target rotation frequency of the (optical disk 1) is obtained by the arithmetic unit 5, and the target rotation frequency is set in a buffer provided in the target frequency setting unit 7.

When the moving position of the optical head of the pickup 2 is obtained by the arithmetic unit 5, the linear motor of the pickup 2 is driven, and the optical head is moved to the moving position.

On the other hand, the rotation frequency of the disk motor 8, that is, the rotation frequency of the optical disk 1 is detected by the frequency detector 9. The rotation frequency of the disk motor 8 (optical disk 1) detected by the frequency detector 9 and the target
The rotation frequency is compared with the rotation frequency by the frequency comparator 10, and frequency information according to the comparison result is supplied to the changeover switch 12.

At this time, since the changeover switch 12 has been switched to the frequency comparator 10 side, this frequency information is converted into a voltage signal by the fV converter 14, and the converted voltage signal is added to the adder 15 and the amplifier. The power is supplied to the disk motor 8 via the control unit 16. The disk motor 8 rotates at a rotation frequency according to the voltage signal thus supplied, and rotates the optical disk 1.

The control of the rotation of the disk motor 8 differs depending on whether the target address is on the outer peripheral side or the inner peripheral side of the current address. Hereinafter, the control of the rotation of the disk motor 8 will be described separately for (1) a case where the target address is on the outer circumference side of the current address and (2) a case where the target address is on the inner circumference side of the current address. .

(1) When the target address is located on the outer circumference side of the current address When the optical head of the pickup 2 reads information at the target address from the optical disk 1, the target rotation frequency of the optical disk 1 is the rotation frequency at the current address. That is, the rotation frequency is lower than the rotation frequency detected by the frequency detector 9.
At this time, the frequency comparator 10 outputs frequency information for reducing the rotation frequency of the disk motor 8.
This frequency information is converted into a voltage signal by the fV converter 14 and controlled by the converted voltage signal, so that the rotation frequency of the disk motor 8 gradually decreases.

The frequency comparator 10 reduces the rotation frequency of the disk motor 8 while determining that the target rotation frequency is lower than the rotation frequency of the disk motor 8 detected by the frequency detector 9. Output frequency information. Disk motor 8 detected by frequency detector 9
Of the target frequency setting device 7
When the frequency becomes equal to the target rotation frequency set in the step (b), the frequency comparator 10 stops outputting frequency information for reducing the rotation frequency of the disk motor 8.

(2) When the target address is on the inner side of the current address When the optical head of the pickup 2 reads the information at the target address from the optical disk 1, the target rotation frequency of the optical disk 1 is the rotation at the current address. The frequency is higher than the rotation frequency detected by the frequency detector 9.
At this time, the frequency comparator 10 outputs frequency information for increasing the rotation frequency of the disk motor 8.
This frequency information is converted into a voltage signal by the fV converter 14, and is controlled by the converted voltage signal, so that the rotation frequency of the disk motor 8 gradually increases.

The frequency comparator 10 increases the rotational frequency of the disk motor 8 while determining that the target rotational frequency is higher than the rotational frequency of the disk motor 8 detected by the frequency detector 9. Output frequency information. Disk motor 8 detected by frequency detector 9
Of the target frequency setting device 7
, The frequency comparator 10 stops outputting frequency information for increasing the rotation frequency of the disk motor 8.

When the rotation frequency detected by the frequency detector 9 becomes equal to the target rotation frequency by the above operation,
The controller 6 determines that the current address supplied from the digital signal processor 4 matches the previously calculated target address, and switches the changeover switch 12 to the synchronization signal detector 11 by a changeover signal. Thereby, the operation returns to the steady state operation.

If the start timing of the movement of the optical head of the pickup 2 and the control of the rotation frequency of the disk motor 8, that is, the rotation frequency of the optical disk 1, are substantially the same, which one is first. And the completion timing may be simultaneous.

As described above, in the optical disk device of this embodiment, the rotation frequency of the disk motor 8, that is, the rotation frequency of the optical disk 1 is adjusted to the specified rotation speed at the target address without detecting the shortest pulse or the longest pulse. Can be frequency. That is, in parallel with the movement of the optical head of the pickup 2, the rotation frequency of the disk motor 8, that is, the rotation frequency of the optical disk 1 can be controlled to the specified rotation speed. Therefore, the time required to access a desired address on the optical disc 1 can be reduced as compared with the conventional example.

In the above embodiment, the case where the present invention is applied to the control of the rotation of the optical disk has been described. However, according to the present invention, if information including address information is spirally recorded at a constant linear velocity, a method other than optical recording, for example, a disk-shaped recording medium on which information is recorded by a magnetic recording method is used. The present invention can be applied to the case where rotation is controlled.

[0050]

As described above, according to the present invention,
Since the rotation frequency of the disk-shaped recording medium can be controlled in parallel with the movement of the reading means (reader) for reading the information recorded on the disk-shaped recording medium, the time required to access a desired address is obtained. Becomes shorter.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an optical disk device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a conventional optical disk device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical disk 2 Pickup 3 Preamplifier 4 Digital signal processor 5 Computing device 6 Controller 7 Target rotation speed setting device 8 Disk motor 9 Frequency detector 10 Frequency comparator 11 Synchronous signal detector 12 Changeover switch 13 Phase comparator 14 f- V converter 15 Adder 16 Amplifier

Claims (6)

(57) [Claims] 1. A driving device for driving a disk-shaped recording medium on which information including address information is spirally recorded at a constant linear velocity, comprising: driving means for rotatingly driving the disk-shaped recording medium; Reading means for reading information recorded on the disc-shaped recording medium which is movable in the radial direction of the disc-shaped recording medium and which is rotationally driven by the driving means; Address information extracting means for extracting address information of the address information, address information obtaining means for obtaining second address information corresponding to desired information recorded on the disk-shaped recording medium, and address information obtaining means for obtaining the address information. Moving means for moving the reading means to a position on the disc-shaped recording medium corresponding to the second address; When the information corresponding to the second address information acquired by the address information acquiring means is read by the reading means, the target rotation frequency of the disk-shaped recording medium is set to the second address information and the disc-shaped recording medium. Frequency calculating means for calculating based on the information recording state, and a rotational frequency of the disc-shaped recording medium or the driving means.
Frequency detecting means for detecting the number, and rotational driving of the disk-shaped recording medium by the driving means
And a control means for controlling, wherein, prior to said moving means the address information acquisition unit acquires
The disk-shaped recording medium corresponding to the second address information;
If the reading means is not moved to a position on the body,
First address information extracted by the address information extracting means
First control means for controlling the driving means based on the address information obtained by the address information obtaining means.
The disk-shaped recording medium corresponding to the second address information;
When moving the reading means to a position on the body, the
The rotation frequency detected by the frequency detection means is calculated by the frequency calculation.
Until the target rotation frequency calculated by the means is equal to the target rotation frequency,
The disk-shaped recording medium is rotationally driven at the target rotation frequency.
Control means for controlling the driving means as described above, and the rotation frequency detected by the second control means is calculated.
When the target rotation frequency becomes equal to the set target rotation frequency, the first control
A third control for shifting to the control of the driving means by the control means.
And a control unit for driving the disk-shaped recording medium. 2. The drive for a disk-shaped recording medium according to claim 1, wherein said second control means controls said drive means in parallel with movement of said reading means by said movement means. apparatus. And the target rotational frequency wherein said frequency calculating means is calculated, further comprising a frequency comparison means for said frequency detector compares the rotational frequency detected, said second control means, by the frequency comparison means 3. The drive device for a disk-shaped recording medium according to claim 1, wherein a rotation drive of the disk-shaped recording medium by the driving unit is controlled according to a comparison result. 4. The address information obtained by the address information obtaining means is t, the maximum radius of the disk-shaped recording medium is R, the track pitch of the recorded information is p, and the linear velocity of the recorded information is V. And a means for calculating a radius r from the center of the disk-shaped recording medium to which the reading means is to be moved by the moving means in accordance with the following equation: r = 、 (R ² + ( pV / π) × t) The frequency calculating means calculates the target based on a circumference 2πr at a radius r which is a moving position of the moving means and a linear velocity V of information recorded on the disc-shaped recording medium. The drive device for a disk-shaped recording medium according to any one of claims 1 to 3, wherein a rotation frequency is calculated. 5. A disk-shaped recording medium on which information including address information is spirally recorded at a constant linear velocity is rotationally driven by a motor, and is rotated by a reader movable in a radial direction of the disk-shaped recording medium. A method for driving a disc-shaped recording medium that reads information from a driven disc-shaped recording medium, comprising: an address information extracting step of extracting first address information from information read by the reader; Address information obtaining step of obtaining second address information corresponding to desired information recorded in the computer, and moving the reader to a position corresponding to the second address obtained in the address information obtaining step A moving step; and a step corresponding to the second address information acquired in the address information acquiring step. Frequency calculation step of calculating a target rotation speed of the disc-shaped recording medium when the reader reads information based on the second address information and a recording state of the information on the disc-shaped recording medium; The rotation frequency of the disk-shaped recording medium or the motor
A frequency detecting step of detecting, corresponding to the by the moving step the second address information
Reading to a position on the disk-shaped recording medium to be read
If there is no movement of the device, in the address information extracting step,
The motor is controlled based on the extracted first address information.
A first control step for controlling and a second address information corresponding to the moving step.
The reader at a position on the disc-shaped recording medium
If there is a movement, detected in the frequency detection step
The rotation frequency is the target rotation calculated in the frequency calculation step.
Until the rotation frequency becomes equal to the target rotation frequency.
The motor is driven so that the disk-shaped recording medium is rotated.
A second control step of controlling, and a control of the motor by the second control step.
The detected rotation frequency is equal to the calculated target rotation frequency
When it becomes pre SL motor by said first control step
And a third control step for shifting to the control of (1) . 6. The driving of the disk-shaped recording medium according to claim 5, wherein the second control step controls the motor in parallel with the movement of the reader in the moving step. Method.