JPH01208706A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To easily maintain compatibility between an enclosed container and printed circuit board by housing a write current setting circuit in the enclosed container (HDA) and setting the optimum write current corresponding to the characteristic of a magnetic disk inside the container. CONSTITUTION:Since a magnetic head 2, IC head 3, magnetic disk which is not shown in the figure, and write current setting circuit 4 are packed in HDA 1 in an enclosed state, the optimum write current corresponding to the characteristic of the magnetic disk is set in the HDA 1. Therefore, even if the characteristic of the magnetic disk changes, a fixed printed circuit board 8 provided with a controller 5 can cope with the change and, when the fixed printed circuit board 8 is connected to the write current circuit 4 in the HDA 1, this magnetic disk device can execute prescribed operations. Accordingly, one HDA 1 or printed circuit board 8A having a magnetic disk of a characteristic can be exchanged with another HDA 1 or printed circuit board 8A having another magnetic disk of another characteristic and the compatibility of the HDA 1 and printed circuit board 8 can easily be maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk device used in electronic computers, peripheral terminals for electronic computers, and the like.

[Prior Art] Generally, a magnetic disk device has a plurality of magnetic disks (
It is equipped with a shaft that supports and rotates a magnetic medium (magnetic medium), a carriage that supports multiple magnetic heads that can face each magnetic disk, and a voice coil motor that moves the carriage forward and backward.The voice coil motor moves the carriage. By doing so, the magnetic head is positioned at an operating position facing the magnetic disk and a retracted position retracting from the magnetic disk.

The magnetic head and magnetic disk mounting portion of this magnetic disk device have a sealed structure to prevent dust from entering. This sealed structure generally includes a head
Disk assembly (hereinafter abbreviated as HDA)
is used.

FIG. 2 is a circuit configuration diagram showing a conventional magnetic disk device disclosed in, for example, Japanese Unexamined Patent Publication No. 60-143404.
In the figure, IA is an HDA as a sealed container, 2 is a magnetic head, 3 is a head IC connected to the magnetic head 2,
Inside the HDAIA, a magnetic head 2. A head IC 3, a magnetic disk (not shown), etc. are mounted in a sealed state. Further, H 4 is connected to the head IC 3 and the controller 5.
This write current setting circuit 4 is a write current setting circuit placed outside the DAIA, and this write current setting circuit 4 determines the optimum write current when recording data on the magnetic disk by the magnetic head 2 according to the logic signal level from the controller 5. This is to set. Furthermore, 8A is the write current setting circuit 4 and the controller 5.
This is a printed circuit board that is connected to the HD AIA.

Further, FIG. 3 is a circuit diagram showing details of the write current setting circuit 4, and in FIG. 1, 6 and 7 are write current setting resistors (resistance values RAI and RB, respectively).

Next, the operation will be explained. The write current is determined by the resistance value RAt of the write current setting resistors 6 and 7 in the write current setting circuit 4.
It is determined by RB and the logic signal level sent from the controller 5.

Here, a case will be described in which the write current is switched in two stages on the inner circumferential side and the outer circumferential side of the magnetic disk. When the magnetic head 2 is on the inner side, the logic signal level from the controller 5 is set to High level (for example, 1.5V), and the write current is determined only by the resistance value RA of the write current setting resistor 6 (write current setting If the constant is K, the write current value is K/R
A) On the other hand, when the magnetic head 2 is on the outer circumferential side, the logic signal level from the controller 5 is set to Low level (for example, OV), and the resistance value RAt of the write current setting resistors 6 and 7 is set.
It acts in the same way as when RBs are connected in parallel, and the write current value is set to (K/RA)+(K/Re).

For example, when the write current setting constant K is 100, when using a magnetic disk whose optimal write current is 10 mA on the inner circumferential side and 20 mA on the outer circumferential side, l0IIIA:100/
From RA, RA=10Ω, 20mA=100・(1/
RA+1/R8), RB=10 is set to Ω. Similarly, when using a magnetic disk with 20IIA on the inner side and 40mA on the outer side, RA = 5, Ω, R
Ω is set to B=5.

The optimal setting value of the write current is determined by taking into account the variation in electromagnetic conversion characteristics between the magnetic head 2 and the magnetic disk (not shown).
Generally, it is 110% of the write current value corresponding to the peak point of the read voltage value. Setting the write current to this optimal setting maximizes the margin, which is a measure of the reliability of data stored in the device.

Normally, the write current at which the read voltage value peaks is larger on the outer circumferential side than on the inner circumferential side of the same magnetic disk, and also varies depending on the characteristics of the magnetic film of the magnetic disk. for example,
The larger the magnetomotive force of the magnetic film, the larger the write current corresponding to the peak point of the read voltage value. Therefore, in general magnetic disk drives, in order to further optimize the write current,
Current switching is performed in 2 to 8 stages depending on the radial position of the magnetic disk (write current setting circuit 4 shown in Figure 3).
As mentioned above, this is a two-stage switching type).

[Problems to be Solved by the Invention] Conventional magnetic disk drives are configured as described above, so if the characteristics of the magnetic disk change due to differences in manufacturers, etc., it becomes necessary to change the set value of the write current. Due to the difference in the characteristics of the magnetic disks, it becomes necessary to change the circuit constants of the write current setting circuit 4 mounted on the printed circuit board 8A forming the magnetic disk device. Therefore, in the conventional magnetic disk device, when the characteristics of the magnetic disk in the HD AIA change, another printed circuit board having a write current setting circuit 4 that can set the optimum write current according to the characteristics is used. It is necessary to prepare 8A, and HDAIAs with magnetic disks with different characteristics or printed circuit boards 8
It was impossible to exchange A's with each other.

This invention was made to solve the above problems, and provides a magnetic disk device that can extremely easily maintain compatibility between an airtight container (HDA) and a printed circuit board even when magnetic disks with different characteristics are used. The purpose is to obtain.

[Means for Solving the Problems] A magnetic disk device according to the present invention includes a write current setting circuit provided in a closed container that accommodates a magnetic head and a magnetic disk.

[Function] In the magnetic disk device of the present invention, the characteristics of the magnetic disk can be adjusted by housing the write current setting circuit in the same block as the magnetic disk that affects the write current, that is, in a closed container (HDA). A corresponding write current will be set within the sealed container. Therefore, even if the magnetic disks have different characteristics, if a certain printed circuit board having a controller for controlling the write current setting circuit is connected to the write current setting circuit in the airtight container, the magnetic disk drive can perform a predetermined operation.

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1st
FIG. 1 is a circuit configuration diagram showing a magnetic disk device according to an embodiment of the present invention. In FIG. 1, 1 is an HDA as a sealed container, 2 is a magnetic head, and 3 is a head IC 14 connected to the magnetic head 2. is a write current setting circuit which is connected to the head IC 3 and the controller 5 and sets the optimum write current when data is recorded on the magnetic disk by the magnetic head 2 according to the logic signal level from the controller 5. In the embodiment, a magnetic head 2. A head IC 3, a magnetic disk (not shown), and a write current setting circuit 4 are mounted in a sealed state.

Further, 8 is a printed circuit board having a controller 5 for controlling the write current setting circuit 4 and connected to HDAl.

Note that the write current setting circuit 4 is composed of write current setting resistors 6 and 7 similarly to the one shown in FIG. 3, and is controlled by the logic signal level sent from the controller 5 to It is assumed that the write current is switched in two stages on the inner circumferential side and the outer circumferential side.

Next, the operation of the magnetic disk device of this embodiment, which is specially constructed as described above, will be explained.

Since the operation as a normal magnetic disk device is exactly the same as that of the conventional device, the explanation thereof will be omitted.

In this embodiment, since the write current setting circuit 4 is housed in the HDAl, which is the same block as the magnetic disk that affects the write current, the optimum write current corresponding to the characteristics of the magnetic disk is set in the HDAl. is set.

Therefore, even if the characteristics of the magnetic disks differ, the printed circuit board 8 having the controller 5 can be fixed. If this fixed printed circuit board 8 is connected to the write current setting circuit 4 in the HDA 1, the magnetic disk The SF device is capable of performing predetermined operations.

As a result, even if the characteristics of the magnetic disks in the HDAl change, the printed circuit board 8 connected to the HDAI from the outside is not affected at all, and HDAls or printed circuit boards 8A that have magnetic disks with different characteristics can be connected to each other. They can be replaced with each other, making it extremely easy to maintain compatibility between HDAl and the printed circuit board 8.

For example, if there is a magnetic disk device ■ and another magnetic disk device ■ with different characteristics, and a failure occurs in the printed circuit board of the magnetic disk device ■ and a failure occurs in the HDA of the magnetic disk device ■, By connecting the HDA of the magnetic disk device (2) and the printed circuit board of the magnetic disk device (2), it is possible to obtain one normal magnetic disk device.

In the above embodiment, the case where the write current setting value in the HDAl is controlled in two steps according to the radial position of the magnetic disk is explained, but the present invention is not limited to this, and the write current setting value is constant. However, it goes without saying that multiple stages (including no stages) may also be used.

[Effects of the Invention] As described above, according to the present invention, a write current setting circuit is housed in an airtight container (HDA), and an optimum write current corresponding to the characteristics of a magnetic disk is set in the airtight container. Even if the characteristics of the magnetic disk inside the sealed container change, it will not affect the printed circuit board, etc. connected to the sealed container from the outside, and it will be possible to configure the settings so that even if the characteristics of the magnetic disk inside the sealed container change, it will not affect the printed circuit board etc. It becomes possible to exchange sealed containers or printed circuit boards with each other, and there is an effect that compatibility between the sealed containers and printed circuit boards can be maintained extremely easily. Furthermore, it is possible to easily use magnetic disks from multiple manufacturers with different characteristics, which is advantageous in terms of magnetic disk procurement.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram showing a magnetic disk device according to an embodiment of the present invention, FIG. 2 is a circuit configuration diagram showing a conventional magnetic disk device, and FIG. 3 shows details of the write current setting circuit in the conventional device. FIG. In the figure, 1 to head disk as a closed container.
Assembly (HDA), 2...Magnetic disk, 4
・−・Write current setting circuit, 8・−Printed circuit board. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] A magnetic disk device comprising: a closed container in which a magnetic head and a magnetic disk are mounted; and a write current setting circuit capable of setting an optimum write current when recording data on the magnetic disk by the magnetic head; A magnetic disk device characterized in that the write current setting circuit is provided within the sealed container.