JPS63313390A - Magnetic storage device - Google Patents

Abstract

PURPOSE:To stably start even in a low environmental temperature by providing various means for detecting heat, temperature and comparing with a prescribed threshold closely to an integrated circuit in which a write in and write out circuit is incorporated. CONSTITUTION:The resistance value of a thermister 20 is changed according to the temperature and an inclination thereof indicates a negative. A transforming circuit 21 passes a weak current to the thermister 20 to obtain a voltage corresponding to the resistance value of the thermister 20 and output as the output voltage 31 of the transforming circuit. A comparing circuit 22 the voltage VR of a direct current power source 23 with the output voltage 31, outputs a difference voltage DELTAV and a current source 24 passes an output current to a resistor 1. The voltage VR of the direct current source 23 is set in such a manner that a value TR transformed to the temperature of the thermister completely exceeds a lower limit temperature for assuring the operation of the writing and reading integrated circuit 5 and does not exceed an average temperature at the time of a successive operation. The maximum current of the current source 24 is set to a value which does not deteriorate the reliability of the writing and reading integrated circuit 5 according to the rise in the temperature due to the heating of the resistor 1 at the time of a successive discharge. Accordingly, at the time of starting in the low temperature environment, a stable writing and reading operation can be assured.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a magnetic disk device, and in particular, a magnetic head and a magnetic disk are housed in a dust-proof structure, and an integrated circuit for writing and reading the magnetic head is located near the magnetic head. The present invention relates to a magnetic disk device installed in

[Conventional technology]

In conventional magnetic disk drives, the write/read circuit reduces transmission loss of read signals from the magnetic head, improves noise resistance, and speeds up switching of the recording flow to the magnetic head. In order to realize
It is placed near the magnetic head. For this reason, the above-mentioned commitment readout circuit is integrated into a small set of 4 and arranged in the above-mentioned dustproof structure.

Since this integrated circuit supplies a high-speed switching recording current to the magnetic head, it generates a considerable amount of heat, and the normal chip temperature becomes quite high. However, when starting up a magnetic disk drive, the chip temperature is the ambient temperature, which may be below 0° C.69, especially if the chip is placed in an ordinary office in a cold region.

It is quite difficult to operate an integrated circuit with high speed and high frequency band stably in such a wide temperature range, and
A shortcoming is that operation may become unstable when starting at temperatures below ℃.

[Problem that the invention seeks to solve]

The problem to be solved by the present invention is to eliminate the above-mentioned drawbacks of the magnetic disk device and provide a highly reliable magnetic disk device that can stably start up even at low environmental temperatures.

[Means for solving problems]

A magnetic disk device of the present invention includes an integrated circuit incorporating a write/read circuit for writing/reading a magnetic head, a heat generating means disposed close to the integrated circuit, and a temperature detecting means disposed close to the integrated circuit. an integrated circuit case for accommodating the circuit, a driving means for causing the heat generating means to generate heat in response to an input signal, a converting means for converting the output of the temperature detecting means into an electrical signal, and an output signal of the converting means and a predetermined threshold value. and comparing means for comparing the difference numbers and applying a signal corresponding to the difference to the driving means.

[Example] Next, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

Referring to the first section, this embodiment is a write/read integrated circuit that performs J-reading of a magnetic head! In the integrated circuit case 6 accommodating @5, a write/read rectangular circuit 5VcvM
A resistor 1 as a heat generating means and a thermistor 20 as a temperature detecting means are housed in contact with each other. Both ends of the resistor 1 are each connected to two output terminals, and are connected to a current source 24 that causes a current to flow through the resistor 1 in response to the voltage applied to the input terminal, causing the resistor 1 to generate heat. Two output signal lines of the thermistor 20 are connected to each of the two input terminals of the conversion circuit 21. In the comparison circuit 22, the output signal of the conversion circuit 21 is connected to one of two input terminals, and the other input terminal is connected to the positive voltage terminal of the DC power supply 23. The DC power supply 23IIi has a negative voltage terminal grounded and a positive voltage terminal connected to the comparator circuit 220 input terminal.

Figure 2 shows resistor 1 and thermistor 2 inside integrated circuit case 6.
0 is a perspective view showing the mounting state of integrated circuit case 6.
The top cover is removed to reveal the inside.

In FIG. 2, a resistor l and a thermistor 20 are mounted within an integrated circuit case 6 and a convolutional lead-out integrated circuit 5
is implemented in close proximity to. The output terminals of the thermistor 20 and the resistor 1 are each connected to a lead 9 via a bonding wire 10. Therefore the thermistor 20
The temperature of the input readout integrated circuit 5 is always the same as the temperature of the resistor 1.

Next, the operation of this embodiment will be explained.

The resistance value of the thermistor 20 changes with temperature, and its slope is negative. The f conversion circuit 21 causes a weak current to flow through the thermistor 20 to generate a voltage 'I!' corresponding to the resistance 11 of the thermistor 20. il- is obtained and outputted as the conversion circuit output voltage 31. FIG. 3 is a graph showing the temperature characteristics of the conversion circuit output voltage 31.

The comparison circuit 22 compares the voltage VR of the DC power supply 23 and the conversion circuit output voltage 31, and outputs the difference voltage ΔV. The current source 24 applies the output current of the current source 24 corresponding to the graph shown in FIG. 4 to the resistor IK in response to the differential voltage Δ■. That is, the output current of the current source 24 has a value proportional to ΔV when Δ■ is a positive value, that is, when the temperature of the thermistor is low and the conversion circuit output voltage 31 is higher than the voltage VR of the DC current source 23. However, the maximum current IM or more will not flow. When the temperature of the thermistor increases and ΔV shows a negative value, the current source 24
does not output substreams.

The voltage VR of the DC power supply 23 is set so that the value TR converted into the temperature of the thermistor sufficiently exceeds the lower limit temperature guaranteed for operation of the integrated circuit 5 and does not exceed the average temperature during continuous operation. The maximum current IMri of the current source should be a value that does not reduce the reliability of the resistor 1 during continuous outflow, or a value that does not reduce the reliability of the readout integrated circuit 5 due to temperature conditions due to heat generation of the resistor l, whichever is rougher or smaller. set to the value.

Therefore, even if the magnetic disk drive starts up in a low-temperature environment, the thermistor detects the temperature, flows current through the resistor 1, and heats the write-out integrated circuit 5 with the amount of heat corresponding to the power loss, thereby increasing the temperature at which it can be printed. It can be set up inside the embankment.

〔Effect of the invention〕

As explained above, by using the magnetic disk device of the present invention, the convolution readout integrated circuit can be appropriately warmed by the heat generating means and temperature detection means disposed close to the confinement and lead-out integrated circuit, and the operating environment temperature thereof can be heated. You can see the effect of compressing the range. Therefore, even in a low-temperature environment such as an office in a cold region, a stable welding and threading operation can be guaranteed even immediately after startup, and a highly reliable magnetic disk drive can therefore be obtained.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a perspective view showing an example of the integrated circuit case shown in Fig. 1, and Fig. 3 shows the temperature characteristics of the output voltage of the conversion circuit shown in Fig. 1. The graph shown in FIG. 4 is a graph showing the input/output characteristics of the current source output current shown in FIG.

Claims (1)

[Claims] An integrated circuit case housing an integrated circuit incorporating a write/read circuit for writing/reading a magnetic head, a heat generating means provided adjacent to the integrated circuit, and a temperature detecting means provided adjacent to the integrated circuit. , a driving means for causing the heat generating means to generate heat in response to an input signal, a converting means for converting the output of the temperature detecting means into an electrical signal, and comparing the output signal of the converting means with a predetermined threshold value. A magnetic storage device comprising: comparison means for applying a signal corresponding to the difference therebetween to the driving means.