JPS62124604A - Magnetic disk driving device - Google Patents

Abstract

PURPOSE:To improve a drop of the reliability caused by a variance at the time of reproducing a data, by measuring a resolution which a storage medium and a magnetic head in each track have intrinsically, and switching a frequency characteristic of a data reproducing circuit. CONSTITUTION:A frequency characteristic of a data reproducing circuit 9 for reproducing a data which has been written in a storage medium 11 is set in accordance with a resolution which has been measured automatically in each track. The measurement of the resolution is repeated, whenever a device enters into a preparatory period before storage and reproduction of the data become possible. Setting of a frequency in the data reproducing circuit 9 is repeated, whenever a moving track is instructed. In this way, deterioration of the reliability at the time of reproduction, caused by a variance of the resolution which the storage medium 11 and a magnetic head 12 have intrinsically can be improved. In this regard, the resolution in the track is measured automatically, and in accordance with it, the frequency characteristic of the data reproducing circuit can be set automatically.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention automatically measures the frequency characteristics of the data reproducing circuit of a magnetic disk drive by automatically measuring the resolution unique to the storage medium and magnetic head in each track, and immediately responds to the frequency characteristics of the data reproducing circuit of a magnetic disk drive. The present invention relates to a device that performs switching.

Large amounts of digital data are stored on rotating storage media. In order to increase the number of information points stored in one track, it is required to increase the number of magnetization reversals per unit length. At this time, the ratio of the output amplitude when reproducing the signal with the highest writing frequency to the output amplitude when reproducing the signal with the highest writing frequency (this is called resolution) becomes smaller, and peak shift and jitter increase, causing Reliability deteriorates. In this case, is the frequency characteristic of the reproduction circuit corresponding to the resolution unique to the storage medium and magnetic head for each track? If set optimally, deterioration in reliability during playback can be improved.

[Outline of the invention]

According to the present invention, the frequency characteristics of one path of data reproduction for reproducing data stored in a storage medium are set according to the resolution automatically measured for each track. Measurement of resolution is repeated each time a preparation period is entered before data can be stored and reproduced. The frequency setting in the data reproducing circuit is repeated each time a moving track is commanded.

[Prior art]

Conventionally, there is a method in which the entire trunk is divided into several blocks and the frequency characteristic of the reproduction circuit is switched for each block. However, in this case, it is only possible to adapt the frequency characteristics to changes in linear recording density due to differences in track radius, but it is not possible to cope with deterioration in reliability due to individual variations between the storage medium and the magnetic head.

[Purpose of the invention]

The resolution of each track is automatically measured and the frequency characteristics of the data reproducing circuit are automatically set in accordance with the resolution in order to improve reliability during playback due to variations in resolution inherent in storage media and magnetic heads. All equipment is provided.

[Explanation based on examples]

Refer now to FIG. FIG. 1 shows a schematic diagram of a magnetic data system according to the present invention, in which a plurality of storage media 11 are shown mounted on a spindle 13 for rotation.

The head arm portion 14t: is driven back and forth by the actuator 15 relative to the storage medium 11. storage medium l
Mounted on the arm part 14 are a plurality of magnetic heads 12 adapted for reproducing data written thereon and for writing when commanded to write data.

During a predetermined period, the controller 1 sends a command to the servo circuit 3 and the magnetic head selector 1 to select the track on which the resolution is to be measured.Then, a signal of the lowest frequency is sent to the write circuit 4 to select the magnetic head selector. It looks at the storage medium 11 via the lO and the magnetic head 12, then sends a command to the frequency characteristic calculation/storage unit 2, receives the output amplitude when reproducing the lowest frequency signal from the A/D converter 5, and stores it. Prepare the reproduction signal from the magnetic head 12, magnetic head selector 10, amplifier 8, and A/D converter 5.
The signal enters the frequency characteristic calculation/storage unit 2 via , where the amplitude value is stored. After that, the controller 1 similarly writes the highest frequency signal and similarly stores the amplitude value of the reproduced signal in the frequency characteristic calculation/storage section 2. Similar measurements were made using the primary 0 track, which calculates and stores the frequency characteristics of the data reproducing circuit 9.

Repeat calculations and memorization within a specified range.

The controller 2 sends a frequency characteristic calculation-memory unit 2Vc command each time a moving track is commanded from the outside during the playback period, and first calculates the frequency characteristics of the filter 70 in the data playback circuit 9. Switch it whenever you want.

The general relationship between resolution and frequency characteristics in the data reproducing circuit 9 is shown in Figure 2.

〔Effect of the invention〕

By measuring the unique resolution of the storage medium and magnetic head for each track and switching the frequency characteristics of the data reproducing circuit accordingly, it is possible to improve reliability degradation during data reproduction due to variations in the storage medium and magnetic head. .

[Brief explanation of drawings]

FIG. 1 is a drive circuit diagram of a type Qlil device to which the present invention is applied. Figure 2 shows the general relationship between the resolution in the present invention and the frequency characteristics in the data reproducing circuit? Frequency diagram shown. 1...Controller 2...Frequency characteristic calculation/storage section 3@-Servo circuit 4...Write circuit 13--Subi/Dollar 5...A/
D converter 14 a・Arm parts 6・11 Hals detection unit 15・Fist actuator 7th filter 8・e amplifier 9・・Data regeneration circuit 10−・Magnetic helad selector 11 ・・dself 1st medium p door kitsune zesufu Figure 1

Claims (5)

[Claims] (1) In a type of magnetic disk drive that switches the frequency characteristics of the data reproducing circuit on each track based on the resolution unique to the combination of the recording medium and magnetic head, (a) the above resolution is automatically changed on each track of the recording medium; (b) a device that calculates and stores the frequency characteristics of the data reproducing circuit in each track according to the measured resolution; and (c) a device that calculates and stores the frequency characteristics of the data reproducing circuit in accordance with instructions from the calculating and storing device. 1. A magnetic disk drive device comprising: a device for switching characteristics. (2) The magnetic disk drive device according to claim 1, wherein the resolution is measured in all tracks of the recording medium, and the frequency characteristic is switched for each track. (3) Each track of the recording medium is divided into blocks having a significant difference in resolution, the resolution is measured only in tracks representing the blocks, and the frequency characteristics are switched for each block. The magnetic disk drive device described in . (4) The magnetic disk drive device according to claim 1, wherein the resolution is measured in the innermost track and the outermost track and the frequency characteristics are switched. (5) The magnetic disk drive device according to claim 1, wherein the device for calculating and recording the resolution of each track and the frequency characteristics of the corresponding reproduction circuit includes a microprocessor.