JPH03187073A - Track servo mechanism for disk drive device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a track servo mechanism for a disk drive device in which a reproducing head and a recording head are separately provided on a rotating support arm.

[Summary of the Invention] The present invention provides a disc in which a reproducing head and a recording head are separately provided on a rotating support arm, and the reproducing head and the recording head are moved approximately in the radial direction of the disc by rotation of the support arm. In the drive device, in a recording mode, a shift amount of the recording head in a disk radial direction with respect to the reproduction head at a target track position is determined, and the recording head is controlled to off-track in the opposite direction by this shift amount. Since the head scans the track center of the track servo signal and the data signal is written at a position that matches the track center of the servo signal, off-track does not occur during playback mode, and problems such as noise and reading errors caused by off-track are avoided. It's something that doesn't exist.

[Prior Art] Conventionally, as head displacement means for disk drive devices, there are two types: a linear type that moves a support arm linearly to displace the head in the radial direction of the disk, and a linear type that moves the support arm linearly to displace the head in the radial direction of the disk. There is a rotating type that allows displacement, and the rotating type is preferable in order to make the device smaller and lighter.

On the other hand, in order to cope with higher track densities, a magnetoresistive head with excellent reproduction sensitivity characteristics even with a narrow track width has been developed, but this magnetoresistive head does not have recording capability. Therefore, when using a magnetoresistive head, it is necessary to provide another recording head and arrange the two heads in parallel.

By employing a rotating support arm and separately attaching a reproducing head and a recording head to this support arm, it is possible to produce a compact, lightweight, high-density recording/reproducing disk drive device.

[Problem to be solved by the invention] However, in the above disk drive device,
Since the reproducing head and the recording head are arranged at regular intervals and displaced on the circumference, for example, as shown in FIG. 10, the reproducing head (Hp) and the recording head (H
r) so that each center is located on the track center line (C2), both heads (Hp
), (Hr ) center is the track center! (c-). When the playback head (Hp) applies track servo and executes the recording mode, the recording head (Hr) scans the off-track position except for the innermost track position, as shown in FIG. 11(a). The data signal recorded at (Hr) is the track center line (
It is recorded at a position off-track from C2). When reproducing a recording signal recorded in this way, the center of the reproducing head (Hp) is the track center i! 1 (c-), the recording head (Hr) scans the off-track position of the data signal except for the innermost track (Ti), resulting in noise, reading errors, etc. was there.

Therefore, in the present invention, in the recording mode, the recording head scans the just track position of the servo signal on all tracks, thereby eliminating noise, reading errors, etc. caused by recording signals being recorded at off-track positions of the servo signal. An object of the present invention is to provide a track servo mechanism for a disk drive device that prevents this from occurring.

[Means for Solving the Problems] A track servo mechanism for a disk drive device according to the present invention for achieving the above object includes a reproducing head and a recording head at the distal end of a support arm whose base end side is rotatably supported. The playback head and the recording head are moved approximately in the radial direction of the disk by the rotation of the support arm, the servo signal recorded on the disk is picked up by the playback head, and the picked up servo signal is In a track servo mechanism of a disk drive device that performs track servo by moving the rotational position of the support arm accordingly, the current track position is determined from the servo signal picked up by the playback head, and the current track position is determined based on the current track position information. rotate the support arm to position the read head at the target track position, and in the recording mode, determine the amount of shift of the recording head in the disk radial direction with respect to the read head at the target track position, and move the recording head in the opposite direction by this shift amount. Correction control is performed so that the reproducing head is off-track from the center of the track.

[Function] In the recording mode, the playback head picks up the servo signal of the disk and track servo is applied, but if the playback head is off-track from the center of the track of the servo signal by the amount of shift of the recording head in the disk radial direction with respect to the playback head. Since the recording head is controlled to scan the position, the recording head scans the just track position of the servo signal.

[Example code] Embodiments of the present invention will be described below with reference to the drawings.

An embodiment of the present invention is shown in FIGS. 1 to 9(b).

FIG. 2 shows a schematic configuration diagram of the disk drive device. In FIG. 2, the base end of the support arm 1 is rotatably supported by a rotating shaft 2. As shown in FIG.

This rotating shaft 2 is rotated by the driving force of a motor 20 (shown in FIG. 1), and the position of the support arm I is controlled. A slider body 3 is attached to the tip of the support arm I, and the slider body 3 is provided with a magnetoresistive reproducing head (Hp) and a wire-wound recording head (Hr) as shown in FIG. 1O. .

Both the reproducing head (Hp) and the recording head (Hr) are arranged on the center line (CI) of the support arm l at a constant interval,
A recording head (Hr) is provided at the front position, and a reproducing head (Hp) is provided at the rear position. Then, the playback head (Hp) is set at the innermost track (Ti) position of the disc 4.
Both the recording head (Hr) and the recording head (Hr) are configured to just track the servo signal track. Therefore, when the reproducing head (Hp) just tracks on other tracks, the recording head (Hr) is located at an off-track position.

A format diagram of the disc 4 is shown in FIG. In FIG. 3, a disk 4 has a large number of tracks (T) with different radii centered around the rotation center, and a sector servo is provided with a servo section 5 at each track (T) position on the same radius at equal intervals. It is a method. In a disk 4 employing this sector servo system, a servo section 5 and a subsequent data section 6 constitute a sector, and several tens of sectors are provided in a track.

FIG. 4 shows a servo pattern diagram of the servo section 5, and FIG. 5 shows an off-track characteristic diagram of the fine address servo. In FIG. 4, a sector head section (ST) in which a sector start signal is recorded is provided at the head of the servo section 5, and address sections (ADI) and (AD2) in which track addresses are recorded are provided behind this section. ing. Immediately before this address section (ADI), a burst signal indicating that the track is an odd number is recorded in the X section (X), and immediately after the address section (AD2'), a burst signal indicating that the track is an even number is recorded. Seven recorded copies (Y) are provided.

Then, compare the levels of X and Y, and when X > Y, ADI
The track address is detected by employing the address of AD2 when X<Y.

Note that when X=Y, it is recognized that the playback head (Hp) is located in the middle between the tracks. In addition, the address section (ADI
), (AD2) have parts A, part 8, and part 0 in which the A, B, and C signals are recorded, and part A and part 8 are located at different positions, and at the track center line (C7). It is provided at a slightly more distant position and is also provided integrally with parts A and 8 of the adjacent track. Copy 0 is provided consecutively to adjacent tracks, and is configured to pick up whatever course the playback head (Hp) scans. Then, a fine address (FA) is detected by calculating (A-B)/C and calculating a value (FA) corresponding to the off-track amount from the track center line (C2) as shown in FIG. . In FIG. 5, TP indicates the track pitch and TW indicates the track width. By combining the track address and this fine address, the current address of the playback head (Hp) can be known.

FIG. 6 shows a time chart of track address capture during track seek. In FIG. 6, during track seeking, track addresses output by the playback head (Hp) are captured in synchronization with sector servo pulses, and continuously captured addresses are Ha,
If b, then the head movement speed (V) can be found by calculating the formula (la-blTP)/lo.

FIG. 1 shows a circuit block diagram of the track servo mechanism. In FIG. 1, the output signal of the reproducing head (Hp) is guided through an amplifier 7 to an address extracting circuit 8, which extracts a track address and a fine address. The fine address is calculated by calculating (A-B)/C as described above,
This value (0 to ±1) is converted into a digital value, for example, by one hundred, using an A/D converter. The track address and fine address are each supplied to an adder 9, where they are added together to calculate the current address.

This current address is output to the subtracter IO and the speed calculation circuit 11, respectively. The target address is supplied to the subtractor IO, and the address difference obtained by subtracting the current address from the target address is output to the route curve generator 12.

The route curve generator 12 has speed information corresponding to the address difference, and this speed information is a speed profile characteristic shown in FIG.
Output to 3. The speed calculation circuit 11 takes in the current address in synchronization with the sector servo pulse, calculates the head movement speed by calculating <(la-blTP/lo) as described above, and subtracts this current speed from the capacity 3. Output to. The subtracter 13 subtracts the current speed from the target speed to obtain a speed difference, and outputs this speed difference data to the gain control amplifier 14.

On the other hand, the track address of the address sampling circuit 8 is input to the correction value generating circuit 15, and a target fine address is calculated according to this track address. This target fine address is obtained as follows. As shown in FIG. 8, if the distance between the reproducing head (Hp) and the recording head (Hr) is Q, and the angle between the track center line (C1) and the head center line (C8) in the target track is θ, then the reproducing head (Hp) ) The shift I(X) of the recording head (Hr) in the disk radial direction is determined by the equation: X=12 sin θ. The position displaced in the opposite direction by this shift amount (X) (
The fine address corresponding to S) is set as the target fine address. Then, in the recording mode, the target fine address obtained in this way is output to the subtracter 16, and in the playback mode, the target fine address is always set to a zero value (
Just track position) is output. The fine address (current fine address) of the address sampling circuit 8 is input to the subtracter I6, and the fine address difference obtained by subtracting the current fine address from the target fine address is calculated as PI.
It is output to the D circuit (proportional-integral-differential circuit) 17. This PI
The output of the D circuit 17 and the output of the gain control amplifier 14 are selected by a changeover switch I8, and one of them is outputted via an amplifier 19 to a motor 20 for driving the support arm.

The switching position of the changeover switch I8 is controlled by a changeover control circuit 21. Track address difference information of the subtracter IO is input to the switching control circuit 21.

When the track seek mode is started, a control signal is output to position the gain control amplifier 14 side, and when the track address difference becomes within ±1/27P (rack pitch), the PIDID circuit side 7 side is switched. Outputs a control signal.

The operation of the above configuration will be explained below.

In the recording mode, when the track seek mode is started, the changeover switch 18 is switched to the gain control amplifier 14 side. Then, an address extraction circuit 8 extracts a track address and a fine address from the reproduction output picked up by the reproduction head (Hp), and an adder 9
The current address is obtained as the output. The route curve generator I2 outputs target speed data based on the speed profile characteristics from the address difference data, and the speed calculation circuit 11 outputs the current speed calculated from the sequentially sent current addresses to the subtracter 13, and calculates the target speed according to the speed difference. A drive control signal is output from the gain control amplifier 14 to control the rotational speed of the support arm 1.

This rotational speed, that is, the moving speed of the reproducing head (Hp), as shown by the dashed line in FIG. When the target speed becomes equal to the current speed, the target speed is controlled to match the current speed, and the speed is decelerated to follow the speed of the speed profile characteristic. Then, when the track address difference becomes within ±l/2TP, the changeover switch 18 is switched to the PID circuit 1 by the control signal from the changeover control circuit 21.
It can be switched to the 7 side. Track address difference is ±1/2
If it is within TP, the reproducing head (Hp) has reached the target track, and the correction value generation circuit 15 receives the track address of the target track from the address extraction circuit 8 manually. The correction value generation circuit 15 outputs a target fine address according to this track address, and the PID circuit 17
outputs a drive control signal according to the position difference to support arm I.
The rotational position of is controlled. As shown in FIG. 9(a), since the center position of the reproducing head (Hp) is located at the target fine address position, the recording head (Hr) scans over the just track position of the target track. Therefore,
As shown in FIG. 9(b), a data signal is recorded in the data section 6 at a position that coincides with the track center line (C2).

In the playback mode, the correction value generation circuit 15 always outputs a zero value as the target fine address, so the playback head (
Hp) just tracks the track center line (C=), so a proper reproduction signal can be obtained.

In this embodiment, the case of the sector servo method has been described, but the present invention can be applied in substantially the same way to the case of the deep servo method.

[Effects of the Invention] As described above, according to the present invention, a reproducing head and a recording head are separately provided on a rotary support arm, and rotation of the support arm moves the reproducing head and the recording head to the disk. In a disk drive device that moves approximately in a radial direction, in a recording mode, a shift amount of the recording head in the disk radial direction with respect to the playback head at a target track position is determined, and the playback head is off-track in the opposite direction by this shift amount. With this control, the recording head scans the track center of the track servo signal and the data signal is written at a position that matches the track center of the servo signal, which eliminates inconveniences such as noise and read errors caused by off-track during playback mode. It has the effect of not having any.

[Brief explanation of drawings]

1 to 9(b) show embodiments of the present invention, and the first
The figure is a circuit block diagram of the track servo mechanism, Figure 2 is a schematic diagram of the disk drive device, Figure 3 is a disk format diagram, Figure 4 is a servo pattern diagram of the servo section, and Figure 5 is a diagram of the fine address servo. Off-track characteristic diagram, Figure 6 is a timing chart of track address capture during track seek, Figure 7 is a characteristic diagram of speed profile, Figure 8 is a diagram showing shift amount calculation, Figure 9 (a ) is a diagram showing the head scanning state in the recording mode, FIG. 9(b) is a diagram showing the recording state, and FIG.
11(b) show the conventional example, FIG. 10 shows the head arrangement state for each track position, FIG. 1F(a) shows the head scanning state in the recording mode,
Figure f (b) is a diagram showing the recording state. 1...Support arm, 4...Disc, Hp...Reproducing head, Hr...Recording head. Tesisku F Liar device's inconvenience 1 fl fragrance &, Figure 2 Figure 3 Off trough 7 amount Fine address 7-K (n Off track 1 line diagram Figure 5 Figure 6 Figure '-S Calculation of shift t Left hand diagram Figure 8 - T-Fil Go no Heiichi/Desakiakisha and T-entrance (conventional) Figure 11 (a) 2 Tjiroku combed sugar diagram (Hito) No. Figure 11(b)

Claims (1)

[Claims] (1) A reproducing head and a recording head are separately provided at the tips of a support arm whose base end side is rotatably supported, and rotation of the support arm moves the reproducing head and the recording head approximately in the radial direction of the disk. , in a track servo mechanism of a disk drive device that picks up a servo signal recorded on the disk with the playback head, and performs track servo by moving the rotational position of the support arm according to the picked up servo signal; The current track position is determined from the servo signal picked up by the playback head, and based on this current track position information, the support arm is rotated to position the playback head at the target track position, and in the recording mode, the playback at the target track position is performed. A track servo mechanism for a disk drive apparatus, characterized in that a shift amount of the recording head in the disk radial direction with respect to the head is determined, and correction control is performed to move the reproducing head off-track from the track center in the opposite direction by the shift amount.