JPH0428002A - Magnetic memory device - Google Patents

Abstract

PURPOSE:To enable both an in-plane magnetic recording medium and a vertical magnetic recording medium to be used by outputting a signal from an attenuator when a recording medium in use is the former medium and a signal from a differentiation circuit when it is the latter medium by a signal selection circuit. CONSTITUTION:This device is comprised of the magnetic recording medium 1, a recording medium kind detecting part 2, a ring type magnetic head 3, a reproducing amplifier circuit 4, a delay circuit 5, the attenuator 6, the differentiation circuit 7, the signal selection circuit 8, a differential amplifier 9, and a zero cross detection circuit 10. The signal selection circuit 8 outputs the signal from the attenuator 6 when the recording medium in use is the in-plane magnetic recording medium, and outputs the signal from the differentiation circuit 7 when it is the vertical magnetic recording medium. Thereby, it is possible to use both the vertical magnetic recording medium capable of performing recording with high density and an ordinary in-plane magnetic recording medium, which extends the scale of a computer system.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to magnetic storage devices such as magnetic disks and magnetic tapes, and particularly to magnetic storage devices that can use both perpendicular magnetic recording media and longitudinal magnetic recording media. Regarding equipment.

[Prior Art] Conventional magnetic storage devices generally use a recording medium having in-plane magnetic anisotropy and a ring-shaped magnetic head. A reproduced data detection circuit of a magnetic storage device using such a longitudinal magnetic recording medium is composed of a differentiation circuit 11 and a zero-cross detection circuit 10, as shown in FIG. By passing the reproduced amplified signal from the magnetic head through this reproduced data detection circuit, a data pulse corresponding to the peak position of the reproduced amplified signal is reproduced.

On the other hand, in recent years, magnetic recording media such as Co--Cr having magnetic anisotropy in a direction perpendicular to the film surface have been actively researched as having high-density recording characteristics.

Single-pole heads and conventional ring-type magnetic heads are being considered as magnetic heads for perpendicular magnetic recording.

A single-pole head is a head dedicated to perpendicular magnetic recording, and its reproduction waveform is almost the same as the waveform when a conventional longitudinal magnetic recording medium is reproduced with a ring-type magnetic head. Therefore, it uses almost the same reproduction data detection circuit as the conventional one. Can be used.

On the other hand, a ring-type magnetic head is a head used for in-plane recording, but when a perpendicular magnetic recording medium is recorded and reproduced with a ring-type magnetic head, the isolated waveform is different from that of a conventional longitudinal magnetic recording medium. , resulting in an asymmetric dipulse waveform, so a reproduction data detection circuit different from the conventional one is required to implement this into a device. The reproduced data detection circuit in such a perpendicular magnetic recording medium and ring head system consists of a delay circuit 12, a differentiation circuit 13, a differential amplifier 9, and a zero-cross detection circuit 10, as shown in FIG. A method in which the zero-crossing point of the difference signal between the delayed waveform and the differentiated waveform of the original waveform is used as the data point (Japanese Patent Laid-Open No. 62
-43805) and the like are known.

[Problem to be solved by the invention]

However, the longitudinal magnetic recording media that have been used so far have become widespread, and especially in systems with replaceable media such as flexible disks, the large number of longitudinal magnetic recording media that have been It is almost impossible to rewrite all information onto a perpendicular magnetic recording medium. Furthermore, when one computer system has both a disk drive for perpendicular magnetic recording media and a disk drive for conventional longitudinal magnetic recording media, there is a problem in that the entire system becomes large and expensive.

An object of the present invention is to provide a magnetic storage device that can use both a perpendicular magnetic recording medium capable of high-density recording and a conventionally popular longitudinal magnetic recording medium.

[Means to solve the problem]

The present invention provides a magnetic storage device that uses a removable magnetic recording medium and detects digital data from signals recorded and reproduced by a ring-shaped magnetic head. a recording medium type detection unit that detects whether or not the magnetic head is present; a delay circuit that delays the reproduced amplified signal from the magnetic head for a certain period of time; and an attenuator that attenuates the reproduced amplified signal by approximately the same amount as the attenuation amount of the delay circuit; a differentiation circuit that differentiates the reproduced amplified signal; a signal selection circuit that switches between the output of the attenuator and the output of the differentiation circuit according to a signal from the medium type detection section; and an output signal of the delay circuit and the signal selection circuit. It has a differential amplifier that detects the difference between the output signal of the circuit and a zero-cross detection circuit that detects the zero-cross position of the output of the differential amplifier. When the recording medium used is a perpendicular magnetic recording medium, the signal from the attenuator is outputted, and when the recording medium used is a perpendicular magnetic recording medium, the signal from the differentiating circuit is outputted.

The present invention also provides a magnetic storage device that uses a removable magnetic recording medium and detects digital data from signals recorded and reproduced by a ring-shaped magnetic head, in which the recording medium used is a longitudinal magnetic recording medium or a perpendicular magnetic recording medium. a differentiating circuit that differentiates the reproduced amplified signal from the magnetic head; a delay circuit that delays the reproduced amplified signal for a certain period of time; and a signal from the recording medium type detector. a signal selection circuit that switches between the output of the delay circuit and no signal; a differential amplifier that detects the difference between the output signal of the delay circuit and the output signal of the signal selection circuit; and a zero cross of the output of the differential amplifier. and a zero cross detection circuit for detecting a position, and the signal selection circuit outputs no signal when the recording medium used is a longitudinal magnetic recording medium, and outputs no signal when the recording medium used is a perpendicular magnetic recording medium. is characterized in that it outputs a signal from the delay circuit.

〔Example〕

Examples of the present invention will be described below.

(Embodiment 1) FIG. 1 is a block diagram of a magnetic storage device that is a first embodiment of the present invention. This magnetic storage device includes a magnetic recording medium 1
．． Recording medium type detection section 2. Ring type magnetic head 3. Regenerative amplifier circuit 4. Delay circuit 5° attenuator 6. Differential circuit 7. Signal selection circuit 8. Differential amplifier9. It is composed of a zero-cross detection circuit 10.

A ring-type magnetic head is used as the magnetic head so that both a perpendicular magnetic recording medium capable of high-density recording and a conventional longitudinal magnetic recording medium can be used. When the magnetic recording medium 1 is a perpendicular magnetic recording medium, the isolated reproduction waveform reproduced from this recording medium by the ring-shaped magnetic head 3 is as follows.
This results in an asymmetric dipulse waveform. The signal selection circuit 8 selects the differentiating circuit 7, and the differential amplifier 9 detects the difference signal between the waveform passed through the delay circuit 5 and the differentiating circuit 7, and the zero-crossing position is detected by the zero-crossing detection circuit. I
A reproduction data pulse can be obtained by detecting with O.

On the other hand, when the magnetic recording medium 1 is a longitudinal magnetic recording medium, a differential circuit is normally used as the reproduced data detection circuit as shown in FIG. Circuit 5. An attenuator 6 and a differential amplifier 9 are used.

This is done by the signal selection circuit 8 selecting the attenuator 6. Let the reproduced amplified signal be f (t), and the delay circuit 5
Assuming that the delay time is t4 and the degree of attenuation is A, the delay circuit 5
The output of the differential amplifier 9 is A,·f (t-td), and if the attenuation degree of the attenuator 6 is set equal to the attenuation degree Ad of the delay circuit 5, the output signal of the differential amplifier 9 is A, · (f (t -td) -f (t) 1 curvature -A
, ·f'(t) ·Proportional to 1°, that is, approximately proportional to the differential signal f'(t). Therefore, data on a longitudinal magnetic recording medium can be reproduced by simply switching the differentiating circuit 7 to the attenuator 6 with a circuit having almost the same configuration as the reproduced data detection circuit for perpendicular magnetic recording.

This example will be explained in more detail.

In FIG. 1, a Sendust head was used as the ring-shaped magnetic head 3. A flexible magnetic disk housed in a jacket is used as the magnetic recording medium. If it is a perpendicular magnetic recording medium, a hole is made in the jacket at a predetermined position, and if it is a longitudinal magnetic recording medium, the hole is The recording medium type detection unit 2 is configured to prevent holes from being formed and to detect the presence or absence of holes using an optical sensor. Delay circuit 5
゜Attenuator 6. The differentiating circuit 7 and the signal selection circuit 8 had the configuration shown in FIG. That is, the delay circuit 5 has a configuration in which a matching resistor is attached to a delay line, and the attenuator 6 is configured with a resistor, and its attenuation degree is approximately equal to 0.5 of the attenuation degree of the delay circuit 5. Differentiator circuit 7 is composed of a resistor and a capacitor. A CMOS analog switch controlled by a detection signal from the recording medium type detection section 2 was used as the signal selection circuit 8 for switching signals depending on the type of recording medium. Further, the zero-cross detection circuit 10 used a circuit similar to that used in conventional longitudinal magnetic recording.

In a magnetic storage device having such a configuration, data transfer is performed using, as the magnetic recording medium 1, a conventionally popular longitudinal magnetic recording medium with a Co-coated Fezes coating film.
Even when used at a data transfer rate of 0 kb/s and a data transfer rate of 2.5 Mb/s using a perpendicular magnetic recording medium made of a CoCr alloy sputtered film capable of high-density recording, data can be transferred with a wide phase margin. I was able to play it.

(Embodiment 2) FIG. 2 is a block diagram of a magnetic storage device that is a second embodiment of the present invention. This magnetic storage device includes a magnetic recording medium 1
．． Recording medium type detection section 2. Ring type magnetic head 3. Regenerative amplifier circuit 4. Delay circuit 5° Differential circuit 7. Signal selection circuit 8
．． Differential amplifier9. It is composed of a zero-cross detection circuit 10.

In this embodiment, the differentiating circuit 7 used for perpendicular magnetic recording media is used as the differentiating circuit for longitudinal magnetic recording media,
Data on the longitudinal magnetic recording medium can be reproduced by simply switching the signal using the signal selection circuit 8 so that the signal from the delay circuit 5 does not enter the differential amplifier 9.

whether the magnetic recording medium used is a longitudinal magnetic recording medium;
It is necessary to switch the signal depending on whether the recording medium is a perpendicular magnetic recording medium, but in the magnetic storage device of this embodiment, it is possible to record whether the recording medium used is a longitudinal magnetic recording medium or a perpendicular magnetic recording medium. The signal selection circuit 8 is configured to detect by the medium type detection section 2 and switch the signal based on the detection signal from the medium type detection section 2. This makes it possible to use both a perpendicular magnetic recording medium capable of high-density recording and a longitudinal magnetic recording medium, which has been widely used in the past, in one magnetic storage device.

This example will be explained in more detail.

In the magnetic storage device having the configuration shown in FIG.
A sendust head was used. A flexible magnetic disk housed in a jacket is used as the magnetic recording medium. If it is a perpendicular magnetic recording medium, a hole is made in the jacket at a predetermined position, and if it is a longitudinal magnetic recording medium, the hole is The recording medium type detection unit 2 is configured to prevent holes from being formed and to detect the presence or absence of holes using an optical sensor. Delay circuit 5. The differentiating circuit 7 and the signal selection circuit 8 had the configuration shown in FIG. That is, the delay circuit 5 has a configuration in which a matching resistor is attached to a delay line, and the differentiator circuit 7 has a configuration in which a resistor and a capacitor are configured. A CMOS analog switch controlled by the detection signal from the recording medium type detection section 2 is used as the signal selection circuit 8 for switching signals depending on the type of recording medium, and is not used when the recording medium used is a longitudinal magnetic recording medium. A signal (ground) is selected, and if the recording medium used is a perpendicular magnetic recording medium, the signal from the delay circuit 5 is selected. Further, as the zero-cross detection circuit IO, a circuit similar to that used in conventional longitudinal magnetic recording was used.

In a magnetic storage device having such a configuration, a conventionally popular longitudinal magnetic recording medium with a Co-coated-FezOi coated film is used as the magnetic recording medium 1 to perform data transfer.
Even when used at a data transfer rate of 0 kb/s and a data transfer rate of 2.5 Mb/s using a perpendicular magnetic recording medium made of a CoCr alloy sputtered film capable of high-density recording, data can be transferred with a wide phase margin. I was able to play it.

〔Effect of the invention〕

As described above, the magnetic storage device of the present invention can use both a perpendicular magnetic recording medium capable of high-density recording and a conventionally popular longitudinal magnetic recording medium, thereby increasing the size of the computer system. Instead, new high-density, large-capacity recording media can be used, and recording media that store conventional data can also be used.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of one magnetic storage device of the present invention, FIG. 2 is a block diagram showing the configuration of another magnetic storage device of the invention, and FIG. 3 is the magnetic storage device of FIG. 1. Figure 4 is a circuit diagram of the delay circuit, attenuator 2 differentiation circuit, and signal selection circuit used in the magnetic storage device of Figure 2. Figure 5 is a circuit diagram of the delay circuit, differentiation circuit, and signal selection circuit used in the magnetic storage device of Figure 2. Conventional reproduced data detection circuit for longitudinal magnetic recording FIG. 6 shows a conventionally known reproduced data detection circuit for perpendicular magnetic recording. 1...Magnetic recording medium 2...Recording medium type detection unit 3...Ring type magnetic head 4...Reproduction amplifier 5.12...6...7. 13. ・ ・ 8 ・ ・ ・ ・ 9 ・ ・ ・ ・ ・Delay circuit・Attenuator・Differential circuit・Differential amplifier・Zero cross detection circuit

Claims (2)

[Claims] (1) In a magnetic storage device that uses a removable magnetic recording medium and detects digital data from signals recorded and reproduced by a ring-shaped magnetic head, the recording medium used is a longitudinal magnetic recording medium or a perpendicular magnetic recording medium. a recording medium type detection section that detects whether the read amplified signal is the same as that of the magnetic head; a delay circuit that delays the read amplified signal from the magnetic head for a certain period of time; an attenuator that attenuates the read amplified signal by approximately the same amount as the attenuation amount of the delay circuit; a differentiating circuit for differentiating the reproduced amplified signal; a signal selection circuit for switching between the output of the attenuator and the output of the differentiating circuit according to a signal from the medium type detection section; It has a differential amplifier that detects a difference between the output signal and a zero-crossing detection circuit that detects a zero-crossing position of the output of the differential amplifier, and the signal selection circuit is configured such that the recording medium used is a longitudinal magnetic recording medium. If the recording medium used is a perpendicular magnetic recording medium, the signal from the differentiation circuit is output. (2) In a magnetic storage device that uses a removable magnetic recording medium and detects digital data from signals recorded and reproduced by a ring-shaped magnetic head, the recording medium used is a longitudinal magnetic recording medium or a perpendicular magnetic recording medium. a differentiating circuit that differentiates the reproduced amplified signal from the magnetic head; a delay circuit that delays the reproduced amplified signal by a certain period of time; a signal selection circuit that switches between the output of the delay circuit and no signal; a differential amplifier that detects the difference between the output signal of the delay circuit and the output signal of the signal selection circuit; and a zero-crossing position of the output of the differential amplifier. and a zero-cross detection circuit for detecting a zero cross, and the signal selection circuit outputs a no signal when the recording medium used is a longitudinal magnetic recording medium, and outputs a no signal when the recording medium used is a perpendicular magnetic recording medium. A magnetic storage device characterized by outputting a signal from a delay circuit.