JPH06111457A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To shorten the time to a temperature condition capable of being available for the R/W operation of a head disk assembly(HDA) in a magnetic disk device and to control the R/W operation for delicate temperature change, as well. CONSTITUTION:After power is turned on, the temperature is detected successively in a temperature detection circuit 11, and the detected temperature is stored in a storage circuit 14 as temperature data successively. In a temperature comparator circuit 15, the last time temperature data are taken out from the storage circuit 14 and the temperature difference of this time temperature data is calculated with the last time temperature data, and the calculated temperature difference is compared with an allowable temperature difference set previously, and the R/W operation is controlled according to the compared result of the temperature difference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk device, and more particularly to a data write / read operation (R / W operation).
The present invention relates to a magnetic disk device.

[0002]

2. Description of the Related Art Conventionally, a magnetic disk device of this type has a head and a recording medium such as a disk, and a head disk assembly (HDA) for performing a read / write (R / W) operation on the recording medium by the head. ) Is provided. Generally, in the HDA, in order to prevent thermal off-track due to a rapid temperature change after the power is turned on, as shown in the flowchart of FIG. 5, until the time preset by the timer is reached (step S1), the R / W After reaching the preset time without performing the operation, the temperature of the HDA is monitored (step S2), and it is determined whether the temperature is within the preset allowable temperature (step S3). ,
A signal instructing the R / W operation is output (step S4),
R / W operation is performed.

[0003]

However, in the above-mentioned conventional magnetic disk drive, even if the head is in a temperature state where R / W operation is possible, it must be done after the time preset by the timer has elapsed. No R / W operation is performed. Therefore, there is a drawback in that at least the time set by the timer is required until the R / W operation. Furthermore, after the preset time has passed, the temperature of the HDA is monitored, and the monitored temperature is compared with the set temperature to determine whether or not it is within the set temperature range. For example, even if the monitored temperature changes significantly from the upper limit to the lower limit or from the lower limit to the upper limit of the set temperature range, and the R / W operation is in an unfavorable state, the R / W operation is performed. There is also a drawback that is done.

A technical object of the present invention is to provide a magnetic disk device which can save unnecessary time and therefore can quickly perform an R / W operation.

Another technical object of the present invention is to provide a magnetic disk drive capable of appropriately controlling the R / W operation in response to a sudden temperature change or a subtle temperature change.

[0006]

According to the present invention, in a magnetic disk device which performs a read / write (R / W) operation after the power is turned on, the temperature inside the magnetic disk device is set to a predetermined value after the power is turned on. Detected at the timing, temperature detection means for sequentially outputting the detection results, and the difference between the detection results detected at different timings is compared with a preset temperature difference,
Comparison means for outputting a comparison result signal representing the comparison result, and R for controlling the R / W operation according to the comparison result signal.
A magnetic disk device having a / W control circuit can be obtained.

According to the present invention, a signal representing the temperature is further received, whether or not the temperature is within a predetermined allowable temperature range is searched, and the search result is output to the R / W control circuit. Thus, a magnetic disk drive having a temperature inspection means for controlling the temperature can be obtained.

[0008]

In the present invention, the temperature inside the magnetic disk device is detected at a predetermined timing, and it is compared whether or not the temperature between the temperatures detected at different timings is within the allowable temperature range. A temperature change or a subtle temperature change can be detected, and the R / W operation can be controlled according to the detection result. Further, by searching not only the temperature difference but also whether or not each detection result is within the set allowable temperature range, the R / W operation can be performed within the appropriate temperature range.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic disk device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram for explaining a magnetic disk device according to an embodiment of the present invention, and FIG. 2 is a flow chart for explaining an R / W control operation of the magnetic disk device of FIG.

1 and 2, when the power switch of the HDA is turned on, the operation of the stage of FIG. 2 is performed. Specifically, the temperature detection circuit 11 causes the H
The temperature of DA is measured and detected, and the detected temperature signal 11a is output. The A / D conversion circuit 12 uses the detected temperature signal 11a.
Is received as an input, A / D converted, and the A / D converted digital temperature signal 12a is output. Timer 13
It operates by receiving the digital temperature signal 12a,
The memory circuit 14 is enabled at every preset timing. As a result, the digital temperature signal 12a
Is stored in the storage circuit 14 at a preset timing.

At this time, as shown in the stage of the flow chart of FIG. 2, in the temperature detection circuit 11 to the storage circuit 14, the processes from temperature detection, A / D conversion, timer setting, and temperature data storage are repeatedly performed. Be done.

Further, referring to FIGS. 1 and 2, the temperature comparison circuit 15 receives the digital temperature signal 12a stored in the storage circuit 14 as a temperature data signal 14a, and the temperature data previously stored and the temperature data stored this time are stored. The difference between the temperature data and the temperature data obtained is calculated, and the difference is compared with a preset allowable temperature difference (step Sa1). If the difference is within the allowable temperature difference, the R / W signal 15a is output (step Sa1). Sa
2) If it is not within the range of the allowable temperature difference, the alarm signal 15b is output (step Sa3).

The R / W control circuit 16 has an R / W signal 15a.
If is input, R / W operation is performed (step Sa
5) When the alarm signal 15b is input, R /
The R / W operation is not performed until the W signal 15a is input (step Sa4).

Next, a magnetic disk device according to another embodiment of the present invention will be described with reference to FIG. Temperature detection circuit 1
When the power switch of the HDA is turned on, 1 measures and detects the temperature of the HDA and outputs a detected temperature signal 11a.

The A / D conversion circuit 12 includes a detected temperature signal 11
Digital temperature signal 12a obtained by inputting a and A / D conversion
Is output.

In this embodiment, a temperature search circuit 23 is newly added.
Is provided between the A / D conversion circuit 12 and the timer 13. The temperature search circuit 23 receives the digital temperature signal 12a as an input, and as shown in the flowchart of FIG.
It is searched whether the temperature value of the digital temperature signal 12a is within a preset allowable temperature range (step Sb).
1) If the temperature value is within the allowable temperature range, the temperature data is output as the capacitor signal 23a. If the temperature value is outside the allowable temperature range, the alarm signal 23b is output (step Sb2), and the capacitor signal 23a is also output for temperature data transfer.

When the capacitor signal 23a is output to the timer 13, the timer 13 is activated (step Sb
3) When the capacitor signal 14a reaches a preset time, it is stored in the memory circuit 14 (step Sb).
4).

At this time, as shown in the flow chart of FIG. 4, the processes from the temperature detection circuit 11 to the storage circuit 14 are repeatedly performed as in steps Sa1 to Sa5 of FIG. Here, the temperature detection circuit 11, the A / D conversion circuit 12,
The timer 13 and the storage circuit 14 constitute a temperature detection unit that outputs digital temperature signals at different timings.

The temperature comparison circuit 15 inputs the temperature data stored in the storage circuit 14 as a temperature data signal, obtains the difference between the temperature data stored last time and the temperature data stored this time, and sets the difference and the preset value. The comparison result signal obtained by comparing the allowable temperature difference (step Sa1), that is, the R / W signal 15a is output in the case of the allowable temperature difference (step Sa1).
2) If it is not the allowable temperature difference, the alarm signal 15b is output (step Sa3).

The R / W control circuit 16 uses the R / W signal 15a.
It is determined whether or not is input (step Sa4), and R /
When the W signal 15a is input, the R / W operation is performed (step Sa5), and when the alarm signal 15b is input, the R / W operation is not performed until the R / W signal 15b is input.

[0022]

As described above, according to the present invention, the temperature difference between the previous temperature value and the current temperature value stored in the memory circuit is compared with the preset allowable temperature difference value. By making a comparison with a circuit, head control according to a change in temperature becomes possible. In addition, a temperature search circuit for searching whether or not the temperature measured by the temperature detection circuit is within a preset allowable temperature is provided together with the above-described temperature comparison circuit, so that a temperature state in which R / W operation is possible is achieved. It not only shortens the time until it becomes R, but also when there is a slight temperature change.
There is an effect that the / W operation can be controlled.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a magnetic disk device according to an embodiment of the present invention.

FIG. 2 is a flow chart for explaining the operation of the magnetic disk device of FIG.

FIG. 3 is a block diagram of a magnetic disk device according to another embodiment of the present invention.

4 is a flow chart for explaining the operation of the magnetic disk device of FIG.

FIG. 5 is a flowchart for explaining the operation of a conventional example of a magnetic disk device.

[Explanation of symbols]

 11 Temperature Detection Circuit 12 A / D Conversion Circuit 13 Timer 14 Storage Circuit 15 Temperature Comparison Circuit 16 R / W Control Circuit 23 Temperature Search Circuit

Claims (2)

[Claims] 1. A magnetic disk device which performs a read / write (R / W) operation after power is turned on, and after the power is turned on, the temperature in the magnetic disk device is detected at a predetermined timing.
The temperature detection means for sequentially outputting the detection results, a comparison means for comparing the difference between the detection results detected at mutually different timings with a preset temperature difference, and outputting a comparison result signal representing the comparison result, and the comparison R / depending on the result signal
A magnetic disk drive having an R / W control circuit for controlling a W operation. 2. The magnetic disk device according to claim 1,
A temperature inspection means is provided for receiving a signal representing the temperature, searching for whether the temperature is within a predetermined allowable temperature range, and outputting the search result to the R / W control circuit. And a magnetic disk device.