JPH0520820A - Recording and replay apparatus - Google Patents

Abstract

PURPOSE:To surely replay a servo signal without erroneously detecting other signals by a method wherein, in a servo control operation, a servo detection means is operated only near a servo detector. CONSTITUTION:When a servo control circuit detects a servo recognition signal 1 situated in the front part of a servo sector 5, it computes the position on a medium of a head by using a servo signal 2 to be read out after a certain regulated time and executes a servo control operation. The servo recognition signal 1 and the servo signal 2 are recorded in positions which are dislocated by a 1/2 pitch from individual tracks on which a data signal 3 is recorded. Consequently, even when the servo signal and the data signal are replayed by using the same replay circuit, only the servo signal can be replayed surely without erroneously detecting other signals. The title apparatus can be used also in a medium which is provided with a format in which several kinds of servo sectors have been formed in the same track.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording / reproducing apparatus for writing / reading data by a predetermined signal system using a magnetic head, a pickup or the like.

[0002]

2. Description of the Related Art Disk-type and tape-type recording / reproducing devices have been conventionally used as external storage devices for computers and word processors. In this type of recording / reproducing apparatus, a magnetic head writes and reads signals on the circumference of a rotating disk.
At this time, in order to perform positioning of the head with high accuracy,
A method is used in which a disk on which a servo signal is written is used, the head is read, and the position on the medium is detected and controlled.

FIG. 2 is a schematic view illustrating the data side of a disk device (media) using the sector servo system. In the example of FIG. 2, the servo sectors 5 are radially arranged on the disk surface, and the number of servo signals is the same for each track. One or more data sectors 6 for recording data are arranged between the servo sectors 5 while avoiding the servo sectors 5. When a sector servo system as shown in FIG. 2 is used as a method for servoing the data surface of the medium 4, generally, the servo signal and the data signal are read and amplified and reproduced by the same head. FIG. 6 is a timing chart illustrating the relationship between the track position and the servo signal detection time in conventional servo control. Servo signals and data signals read by the same head are read alternately as shown in FIG. From the read signal, the servo signal detection circuit extracts only the servo signal and controls the sector servo.

[0004]

As described above, when the servo signal and the data signal are read by the same reproducing circuit, both signals are reproduced as the same reproducing signal. Therefore, in order to detect the servo signal from the reproduced signal, it is necessary to distinguish the servo signal and the data signal by the component of the reproduced signal. Therefore, in the conventional method, when the signal of the component similar to the servo signal is detected from the signal of the data part, as shown by reference numeral 13 in FIG. 6, this may be erroneously detected as the servo signal. was there. As described above, in the conventional servo control process, there is a problem to be solved in that the signal of the data section may cause a malfunction.

In the case where one data surface is divided into a plurality of zones in the radial direction and the number of servo sectors is changed for each zone, servo sectors with different intervals are provided for each zone. FIG. 5 is a schematic view illustrating the pattern of the zone switching portion when the servo sector interval is changed for each zone. In such a case, FIG.
It may be necessary to overlap servo sectors of different intervals on the same track at the overlapping portions of the zones, as shown in FIG. In this way, when the intervals of the servo sectors are different but the contents of the data signal and the servo signal are the same,
There is also a problem to be solved that such a servo format cannot be used because servo control becomes impossible because servo signals having other unnecessary intervals are also detected.

The present invention has been made in view of the above technical problems, and an object of the present invention is to provide a servo signal and a data signal in the same reproducing circuit in a sector servo system, etc. PROBLEM TO BE SOLVED: To provide a recording / reproducing apparatus capable of surely reproducing only a servo signal without erroneously detecting the signal of No. 1, and used even in a medium having a format in which several kinds of servo sectors are provided on the same track Is.

[0007]

DISCLOSURE OF THE INVENTION The present invention achieves the above-mentioned object in a recording / reproducing apparatus using a sector servo system by activating a servo detecting means only near a servo sector during servo control. is there.

[0008]

In the recording / reproducing apparatus of the present invention, the time interval for reading the servo sector is set in advance in the apparatus, and the servo detecting means is operated only near the servo sector. Therefore, the signal is masked except at the timing of reading the servo signal. Therefore, it operates so as to reliably detect only the servo signal.

[0009]

1 is a timing chart showing an operation example of servo control by a recording / reproducing apparatus to which the present invention is applied.
FIG. 3 is a block diagram showing the configuration of an embodiment of a recording / reproducing apparatus to which the present invention is applied. The magnetic recording / reproducing apparatus of FIGS. 1 and 3 employs a method of controlling recording / reproducing by a magnetic head using a sector servo in order to perform high density recording. Further, as the medium (disk device), for example, a medium having a servo sector pattern as shown in FIG. 2 can be used. 1 and 3, when performing servo by the sector servo method, the servo sector is read, the head position on the data surface of the medium 4 is obtained from the signal, and the servo control of the head 8 (seek operation) is performed based on this. Control). FIG. 4 is a flowchart showing the procedure of this servo control.

The magnetic recording / reproducing apparatus of FIG. 3 reproduces a signal from a rotating medium (disk device) 4 by using a head (magnetic head) 8, amplifies the signal by a read amplifier 31, and outputs a servo signal from the signal. The detection circuit 32 detects the servo signal. After the A / D conversion of this servo signal, data for head position control (for VCM drive) is generated by the microcomputer 33 from the data. This VCM driving data is D / A converted, and the VCM amplifier 3
The position of the head 8 is controlled by amplifying at 4 and drivingly controlling the VCM 7.

In FIGS. 1, 3 and 4, when the servo control circuit detects the servo recognition signal 1 (FIG. 1) at the head of the servo sector 5, the servo signal 2 (FIG. ), The position of the head 8 on the medium 4 is calculated, and servo control is performed. As shown in FIG. 1, the servo recognition signal 1 and the servo signal 2 are recorded at a position shifted by 1/2 pitch from each track on which the data signal 3 is recorded. The actual servo control operation is performed, for example, in the procedure shown in the flowchart of FIG.

In FIGS. 1 and 4, when the medium 4 is inserted, the servo control process is started, and the signal on the medium is read until the first servo recognition signal 1 is detected (step S1). At the same time when the servo recognition signal 1 is read in step S2, the timer 35 (FIG. 3) for designating the servo pattern interval is started in step S3. At this time, after detecting the servo recognition signal 1, the servo signal 2 is read out, and it is judged whether or not this signal is the correct servo signal 2 (step S4 and step S5).
If the servo signal 2 is not correct, the process immediately proceeds to step S6 to reset the timer 35 and wait for the next servo recognition signal 1.

1 and 4, the step S
When it is determined that the correct servo signal 2 has been read in 5, the timer 35 (FIG. 3) is counted for a set time, and the servo detection gate 36 (FIG. 3) is opened immediately before the next servo sector 5 is read. The required servo recognition signal 1 and servo signal 2 are introduced into the servo detection circuit 32, and the servo control of the head 8 is performed by the microcomputer 33 using these signals (step S7).
And read (read) write (write) processing by the head 8 or other processing (step S8)
Do. In the timing chart of FIG. 1, start of the servo control, detection of the first (first) servo recognition signal 1, start of the timer 35, opening / closing of the servo detection gate 36, servo signal by the servo signal detection circuit 32. 2 detection and servo signal read (read)
An example of the timing (sequence) of each operation of opening and closing the gate is shown.

In the above-described embodiment, the servo sector 5 which is read correctly first is selected as the trigger for starting the timer 35 for designating the servo pattern interval, but instead of this, the timer is triggered by the index signal. May be configured to start.

[0015]

As is apparent from the above description, according to the present invention, in the recording / reproducing apparatus using the sector servo system, the servo detecting means is operated only near the servo sector during servo control. Even when a signal and a data signal are reproduced by the same reproducing circuit, only the servo signal can be surely reproduced without erroneously detecting other signals, and a format in which several kinds of servo sectors are provided on the same track There is provided a recording / reproducing apparatus that can be used even in a medium having a.

[Brief description of drawings]

FIG. 1 is a timing chart of head servo control in an embodiment of a recording / reproducing apparatus according to the present invention.

FIG. 2 is a schematic diagram illustrating a sector servo pattern of a medium suitable for use in the recording / reproducing apparatus according to the present invention.

FIG. 3 is a block diagram showing a configuration of a control system in an embodiment of a recording / reproducing apparatus to which the present invention is applied.

FIG. 4 is a flowchart showing an operation procedure of servo control in an embodiment of a recording / reproducing apparatus to which the present invention is applied.

FIG. 5 is a view showing a recording / reproducing apparatus to which the present invention is applied.
It is a schematic diagram which shows a part of data surface of the medium which has a kind of servo sector.

FIG. 6 is a timing chart showing an operation example of servo control of a recording / reproducing apparatus using a conventional sector servo system.

[Explanation of symbols]

 1 Servo recognition signal 2 Servo signal 3 Data signal 4 Media (disk device) 5 Servo sector 6 Data sector 7 VCM 8 Head 32 Servo detection circuit 33 Microcomputer 35 Timer 36 Servo detection gate

Claims (1)

Claim: What is claimed is: 1. A recording / reproducing apparatus using a sector servo system, wherein a servo detecting means is operated only near a servo sector during servo control.