JPS6098572A - Disc driving device - Google Patents

Abstract

PURPOSE:To position extremely accurately an R/W head or the like on a prescribed data track and to attain stable and high density access of a track by detecting the position of a data track formed to store data and positioning an R/W head or the like on the prescribed data track on the basis of the detected signal. CONSTITUTION:The head 1 is constituted of a servo head A (2) servo head B (3), erase head 4, and the R/W head 5. Data tracks (N-1), N and (N+1) have prescribed width W respectively and the interval S between the data tracks is generally expanded larger than the data track width W. The position the R/W head 5 on the prescribed data track recorded in a disc, the head 1 may be positioned so that the amplitude of a signal detected by the servo head A coincides with that of the servo head B.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field of the Invention) The present invention relates to a disk drive device, and particularly to a disk drive device that sets a read/write (R/W) head to a predetermined track at high speed and quickly during access. It is related to the device.

(Technical Background and Problems) In a disk drive device, the R/W head is operated with high precision in order to write data to or read data from predetermined tracks arranged concentrically within the surface of a disk-shaped disk. Moreover, it is necessary to quickly set a predetermined track.

Particularly when storing data at high density on a sheet-like replaceable floppy disk 1 For example, when storing data in the form of perpendicular magnetization, the step method used in conventional floppy disks or the encoder method using a linear motor is used. etc., the track position is always detected and I? Since it does not drive the R/W head, the R/W head is always set to a predetermined track with high precision due to the expansion and contraction of the floppy disk itself due to the accuracy of the drive device or changes in temperature, humidity, etc. There is so much to do! V
It is.

In addition, some types of disk drive devices read servo information recorded in advance on a disk-shaped recording medium and drive the R/W head to a predetermined position based on the servo information. Although it is possible to set it in the trunk, do you need a track to record servo information or to store servo information? ! There were problems in that it had to be prepared, became complicated, and became expensive.

(Object and Structure of the Invention) An object of the present invention is to solve the above-mentioned problems, and includes a servo head that detects the position of a trunk (hereinafter referred to as data track) provided for storing data, and Based on the detection signal detected by the head
R/W with extremely high precision by driving the W head
The purpose is to quickly set the head to a predetermined data 1-rank. Therefore, in the disk drive device of the present invention, at least 211?
11 servo, the R/W head that accesses the data track of the predetermined width, and the erasure that erases the portion other than the data trunk of the predetermined width from the data track written by the R/W head'. and a throat, and the R/
The present invention is characterized in that the W head is aligned with the data trunk having the predetermined width.

(Example of the invention) The present invention will be described in detail below with reference to the drawings.

FIG. 1 is a sharp cutaway diagram illustrating an example of a conventional disk drive device.
FIG. 2 is an embodiment of the present invention, FIG. 3 is an explanatory diagram for explaining an embodiment of the present invention shown in FIG. 2, FIG. 4 is a configuration diagram of an embodiment of the present invention, and FIG. FIG. 6 is an explanatory diagram for explaining the tracking operation according to the invention. FIG. 8 is an explanatory diagram for explaining the seek operation according to the invention.

In the figure, 1 is the head, 2 is the servo head A, 3 is the servo head B, 4 is the erasing head, 5 is the R/W7, 6 is n;
I position amplifier, 7 is positioning ta structure, 8 is AGCi [9
%i5.9 is a low pass filter, 1o.

lo-1 is a buffer amplifier, 11.27 is a differential amplifier,
12 is a compensation filter, 13 is an amplifier 214 is a mode switch, 15 is a power amplifier, 16 is a voice coil motor, 17 is an inertia control section, 18 is a summing amplifier, 19 is a direction discriminator, 20 is a differentiator, 21 is a peak hold circuit,
22. 24 is a changeover switch, 23 is an adder, 25 is a current Iff divider 1.26 is a current integrator ■, 2nd is a trunk number counter, 29 is a CPU instruction, 30 is a target 1-rack.

31 represents a counter, 32 represents a D/A converter, and 33 represents a square root circuit.

FIG. 1(A) shows an example of servo information recorded on the magnetic disk surface, including EVEN (even number) servo track information and 0
1) This shows a state in which D (number of fr) servo track information are arranged alternately.

FIG. 1(B) shows a waveform chart for detecting the head position and head movement direction, and the waveforms detected at the positions ① to ② shown in FIG. 1 are shown.

By reading information from the track shown in FIG. 1 (A) provided on a conventional disk using a head and comparing the amplitudes of signals from two read adjacent odd and even tracks, the position of the head and the position of the head and track can be determined. You can know the direction of movement. for example.

If the read signal is in the form shown in head position (2) in FIG. 1(B), it is located between the two odd and even two trunks.

In this way, some types of conventional disk devices.

Since the servo signal for detecting the head position is stored in part of the trunk that stores data or in the servo 1 rank provided separately, an area or track is required to store the servo signal, and it is generally a fixed disk. There is a problem in that the mechanical parts of devices and the like are manufactured with high precision, resulting in high costs.

Therefore, in the present invention, the position of the data track itself for storing data provided within the disk surface is detected, and the node is driven to a predetermined position based on the detected signal. This will be explained below.

In FIG. 2, numeral 1 in FIG. 2 indicates a head, which is related to the present invention. The head l is a servo head A (2),
Servo head B (3), erase head 4 and R/W
It is composed of a head 5. Data trunk (N-
1-), N, and (N+1) each have a predetermined width W, and the spacing S between the data trunk and the data track is generally set wider than the data trunk width W. The widths of servo heads 8 and B are approximately equal to the data track width W, and the distance between the center position of servo head A and the center position of servo head B is approximately equal to the data trunk width W, and the width of each servo head is approximately equal to the data track width W. The center position is located at the end of the written data track. Also.

As shown in the figure, the positions of servo head 8 and servo head B are shifted in the rotational direction of the disk so as not to interfere with each other.

To precisely align the R/W head 5 with a predetermined data trunk recorded on the disk.

After positioning is performed almost in the vicinity of a predetermined data track using seek control, which will be described later, head 1 is positioned so that the amplitudes of the signals detected by servo head A and servo head B are equal. good.

In FIG. 3, ■ indicates a state in which the amplitudes of the signals detected by servo head 8 (2) and servo head B (3) are equal, and the R/W head 5 is at the center of data track N shown in FIG. Indicates the case in position.

(2) indicates a state in which the amplitude of the signal detected by servo head 8 is smaller than that detected by servo head B, and the R/W head 5 is on data track N shown in FIG.
The case where the position is on the left side of is shown.

■ indicates a state in which the amplitude of the signal detected by servo head 8 is larger than that detected by servo head B, and the R/W head 5 is
The case is shown on the right side of .

■ indicates a state in which the signal is detected only by the servo head B, and the R/W head 5 is on the data track N shown in FIG.
The case is shown in which the data trunk (N-1-1) is located between the data trunk (N-1-1) and the data trunk (N-1-1).

■ indicates a state in which a signal is detected only by the servo head Δ, and indicates a case where the R/W head 5 is located between data track N and data track (N-1) shown in FIG. .

FIG. 4 shows a block diagram of an embodiment of the present invention, which mainly consists of racking control and seek control.

First, tracking control will be explained.

The signals detected by the servo head A (2) and the servo head B (3) mounted on the positioning mechanism section 7 are amplified by the preamplifier 6 and impedance-converted, and sent to the AGC amplifier 8. is input. The envelopes of the amplified signals are extracted by passing through a low-pass filter 9, and the amplified signals are amplified by a buffer amplifier 10. The amplified envelope signals are input to a differential amplifier 11, and the difference is amplified.

? ili compensation filter 12. Amplifier 13. Mode switcher 14. It is supplied to a voice coil motor 16 via a power amplifier 15. Then, the positioning mechanism section 7 is servo-controlled to a predetermined position via the inertia control section 17.

On this occasion,? The ilH filter 12 compensates the phase for optimal servo control. Further, the signals respectively amplified by the buffer amplifiers 10 are input to the summing amplifier 18, and the added signals are supplied to the AGC amplifier 8. As a result, servo head A (2) and servo head B (3
) and the sum of the envelopes of the detected signals is then exactly constant.

The output signals from servo head A (2) and servo head B (3) are stabilized.

Next, seek control will be explained.

The signal detected by the R/W head 5 mounted on the positioning mechanism section 7 when crossing the data track is
The signal is amplified by a preamplifier 6 and subjected to impedance conversion, and is passed through an eye-pass filter 9 to extract an 1:J-p signal. The extracted envelope signal is amplified by buffer amplifier 10-1. The amplified signal (hereinafter referred to as a position detection signal) is sent to the direction discriminator 19. It is supplied to the differentiator 20 and the peak-bold circuit 2.

The direction discriminator 19 determines the moving speed of the R/W head 5 etc.
j In order to detect accurately, the portion where the position detection signal increases is determined to be the on-trunk direction, and the other portions are determined to be the off-1-rank direction, and the changeover switch 22.2 is determined.
4 respectively. In the on-trunk direction, a signal obtained by differentiating the position detection signal from the bass amplifier 10-1 by the differentiator 20 and an output signal from the power amplifier 15 (current signal for driving the voice coil morph 16) are passed to the current integrator I (25 ) are respectively input to the adder 23. Switch 2 to select the added signal
4 to the negative terminal of the differential amplifier 27. The reason why both signals are added in this way is to improve the S/N when calculating the head drive speed.

On the other hand, in the off-track direction, a signal obtained by integrating the output signal from the power amplifier I5 by the current integrator If (26) is input to the negative terminal of the differential amplifier 27.

Then, a peak is detected from the position detection signal by the peak hold circuit 21, and data trough information is extracted. The data track 1n information is input to the trunk number counter 28 and sent to the R/W.

The current trunk N° in which door 5 is located is counted.

The current track N' and the target trunk N(30) based on the CPIJ instruction 29 are input to a subtraction counter 31 and the difference (N-N') is determined. The difference (N-No) is D/A
Converter 32. It is converted into an optimal speed side 0Il value expressed in the form of an analog value via the square root circuit 33, and is input to the positive polarity terminal of the differential amplifier 27.

As described above, the speed value of the throat 5 to the R/W follows the optimum speed control value input to the differential amplifier 27.
'T' (II! lj P
14. /, ) is in the form of a current in the mode switch 14. Voice coil morph 1 via power+fa ffi device 15
6. Then, the R/W head 5 is set to the predetermined value 1.
When the target track N is approached and N-N' = 0, the subtraction counter 31 sends a switching signal to the mode switching device 14, switches to the tracking control described above, and further switches the R/W head 5. to exactly match a given data trunk.

In Figure 5, signal A and signal B are tracking $
An example of a signal for executing IJIIl, shown in ff14 diagram - Bohenode A (2) and servo head B (3)
Examples of signals from data tracks respectively detected by the arrows are shown, and the arrows indicate the maximum signal values that can be detected.

Signal a and signal S show examples of signals after the signals A and B have been passed through the low-pass filter 9 shown in FIG. 4, respectively, and show signals from which envelopes have been extracted. The arrow h' likewise indicates the maximum value that can be detected in the form of an envelope.

The error signal K(b-a) is an example of the output signal of the directional amplifier 11 shown in FIG. These signals indicate that the R/W head 5 is aligning to the data track based on the respective signals.

FIG. 6 shows an example of a position detection signal which is an output signal from the buffer amplifiers 10-1 shown in FIG. 4. The position detection signal is an envelope of a signal detected when the R/W head 5 crosses a data track. The data track No. 7 where the throat 5 is located to the R/W is the 4th one from the position detection signal.
The peak value is detected by the illustrated peak bold circuit 21 and counted by the track number counter 28 as B1.

You can ask for it. At this time, the trunk number counter 28 is reset when, for example, the outermost data track is accessed during startup.

Detection of the ontra and evening directions by the illustrated direction discriminator 19 in FIG. 4 is performed by differentiating the position detection signal shown in FIG. Linearity can be determined by setting a threshold for
This is done.

On the other hand, the off-trunk direction is considered as a case other than the on-1-rank direction.

FIG. 7(A) shows an example of the characteristics of the signal input to the adder 23 shown in FIG.
An example of characteristics for detecting the speed of the W head 5 with a good S/N ratio is shown. This is because the speed of the R/W head 5 is calculated by simply differentiating the position detection signal of the R/W head 5 output from the buffer amplifier 10-1 shown in FIG. 4 in the on-track direction. By differentiating the N detection signal, v
This is because the fi range noise will be emphasized and the S/N will drop.

The high-frequency characteristic of the differentiator 20 shown in FIG. 4 is lowered, and the output signal of the current integrator 1 (25) shown in FIG. 4 is added to compensate for the lowered high-frequency range. be.

FIG. 7(B) shows an example of characteristics for detecting the speed of the R/W head 5 in the off-track direction. The R/W
Current integrator I shown in FIG. 4 for detecting the speed of the head 5
As shown in the figure, I (26) is set to rise earlier than the current integrator 1 (25).

FIG. 8 shows an example of the characteristics of the optimum speed control value outputted from the square root circuit 33 shown in FIG. The optimum speed control value is generally expressed as the square root of the difference (N-N') between the target track N (30) shown in Figure 4 and the current track N° output from the track number counter 2 days. . K is a constant.

The seek control of the R/W head 5 corresponds to the difference (N-N'') between the target track N and the current trunk N''. The desired current is the voice coil motor 16.
When the signal is supplied to the target track N and the contents of the subtraction counter 31 shown in FIG. A switching signal is sent to the mode switching device 14 shown in FIG. 4 to automatically shift to the tracking control described above.

(Effects of the Invention) As explained above, according to the present invention, a servo head is provided for detecting the position of a data trunk provided for storing data; In order to align the head etc. with the specified data trunk, the R is highly accurate with an extremely simple configuration.
/W head etc. can be aligned to a predetermined data trunk. In particular, even if the floppy disk is easily affected by the temperature, humidity, etc. in the air, such as a floppy disk device, and the floppy disk is replaced.

Since the position of the data track written on the Freonbi disk itself is detected and the position of the R/W head etc. is aligned, it is possible to access the track at a higher density in a much more stable manner than in the past.

[Brief explanation of drawings]

ff51 is an explanatory diagram for explaining an example of a conventional disk drive device, FIG. 2 is an explanatory diagram for explaining an embodiment of the present invention, FIG. 3 is an explanatory diagram for explaining an embodiment of the present invention shown in FIG. FIG. 5 is an explanatory diagram illustrating a tracking operation according to the present invention, and FIGS. 6 to 8 are explanatory diagrams illustrating a seek operation according to the present invention. In the figure, 1 is the head, 2 is the number - Bohenode Δ, :( is the servo head 8.4 is the erase head, 5 is the R/W head, 6 is the preamplifier, 7 is the positioning mechanism section, 8 is the AGC amplifier, 9
is a low pass filter, 1o. lo-1 is a buffer amplifier, 11.27 is a differential amplifier,
What about 12? fi compensation filter, 13 is an amplifier, 14 is a mode switcher, 15 is a power amplifier, 16 is a voice coil motor, 17 is an inertia control section, 18 is a summing amplifier, 19
determines the direction! L20 is a differentiator, 21 is a peak bold circuit, 22.24 is a changeover switch, 23 is an adder, 2
5 is a current distiller I, 26 is a current integrator II, 28 is a track number 81 counter, 29 is a CPU 1rI, and 30 is a target track. 31 represents a subtraction i1 counter, 32 represents a D/A converter, and 33 represents a square root circuit. Patent Applicant Alps Electric Co., Ltd. Representative Patent Attorney Fumihiro Hase (3 others) 1st M 2nd color child 3 Figure 5 Figure 1', 6th mouth 7th grade 8121

Claims (1)

[Claims] At least 21 data tracks provided at different positions in a direction transverse to a data track of a predetermined width recorded on a disk-shaped magnetic recording medium.
[1i1 servo head, a read/write head that accesses the data trunk of the predetermined width, and a read/write head that accesses the data trunk of the prescribed width.
and an erasing head for erasing a portion other than the data track of the predetermined width from the data track written by the write head. A disk drive device characterized in that the read/write head is aligned with the data track of the predetermined width based on each output signal from the servo head.