JPH08194903A - Data writing method and floppy disc apparatus utilizing the method - Google Patents

Abstract

PURPOSE: To obtain a data writing method which avoids the noise which is caused by old data when overwritten new data are read and suppresses the data reading error and a floppy disc apparatus which utilizes the data writing method. CONSTITUTION: In a floppy disc apparatus which applies a predetermined writing current to a magnetic head 6 to write data on an arbitrary magnetic recording medium 51, a DC current which is larger than the writing current is applied before the data are written on the magnetic recording medium to erase the old data recorded on the part on which the said new data are to be recorded.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data writing method and a floppy disk apparatus using this method, and more particularly to a data writing method for an arbitrary magnetic recording medium and a floppy disk apparatus using this method.

[0002]

2. Description of the Related Art A conventional example is shown in FIGS. In FIG. 3, a magnetic head 54 that writes data on a magnetic recording medium (medium) 51 is connected to a current drive unit 53 that applies a current for magnetic field generation to the magnetic head 54. The current driver 53 is composed of a one-chip IC (R / W_IC) and receives write data 5 received from the outside.
The current is output based on 2. Code 5
Reference numeral 5 denotes a resistor that determines the magnitude of the write current.
Then, when the write data 52 is input to the current driver 53, the current driver 53 applies a write current based on a constant magnitude determined by the resistor 55 to the magnetic head 5.
4 is applied. As a result, a magnetic field is generated in the magnetic head, and desired data is written on the medium 51. At this time, if the existing data exists at the writing position of the new data, the new data is overwritten on the old recording data.

In this case, when overwriting with a large write current, writing can be performed deeper in the magnetic layer of the medium 51 than when overwriting with a small write current, and the writability is improved. The rewritability of data by this overwriting is generally called OW, and the better the OW characteristic, the higher the rewritability. This OW characteristic is somewhat different depending on the model of the floppy disk device, and even in the same model, the characteristic is different due to mass production.

[0004]

However, in the above conventional example, due to the difference in the OW characteristics between the models, the matching is performed when the medium written in one floppy disk device is used in the other floppy disk device. The deviation occurs. In particular, when data is overwritten on a medium (FIG. 4A) in which data is written by a floppy disk device having good OW characteristics, data is overwritten by a floppy disk device having bad OW characteristics.
As shown in FIG. 4B, old data exist in a deep layer side by side, which appears as noise at the time of reproduction, resulting in a data read error.

[0005]

An object of the present invention is to improve the inconvenience of the conventional example, and in particular, to prevent the generation of noise due to old recording data when reading overwritten new recording data, and to suppress data reading error. It is an object of the present invention to provide a writing method and a floppy disk device using this method.

[0006]

According to a first aspect of the present invention, in a floppy disk device for applying a predetermined write current to a magnetic head to write data to an arbitrary magnetic recording medium, data is written to the magnetic recording medium. Before writing the data, a method is adopted in which the old recorded data in the data writing portion is directly erased with a current value larger than the write current.

According to a second aspect of the invention, a magnetic head,
The magnetic head is provided with a current drive unit that applies a write current, a current setting unit that sets the magnitude of the write current in the current drive unit, and a control unit that controls the operations of these units. Among these, the current setting unit has a function of setting a larger current value in the current driving unit when erasing data than when writing data. Further, the current drive unit has a function of applying a DC current for erasing data to the magnetic head when the current setting unit sets a larger current value than that at the time of writing data.

According to the third aspect of the present invention, the control unit has a function of instructing each unit to erase the old record data in the data writing portion before writing the data.

According to a fourth aspect of the invention, the current setting section includes:
A current value storage unit that stores in advance a current value for writing or erasing data to be set in the current drive unit and a current value stored in the current value storage unit based on a data writing or erasing command from the control unit. It is configured to include a setting control unit for setting the current drive unit.

According to the fifth aspect of the invention, the current value storage means is an EEPROM.

The above aims to achieve the above-mentioned object.

[0012]

According to the invention described in claim 1 or 2, when the control unit instructs each unit to erase the old record data recorded on the magnetic recording medium, the current setting unit causes the current drive unit to write the normal data. Sets a current larger than the current applied to the magnetic head in the current driver. Then, the current drive unit to which a current larger than the normal write current is set applies a DC current for erasing data to the magnetic head based on the magnitude of the current set by the current setting unit. The magnetic head generates a magnetic field according to the direct current input by the current driver, and non-waveform data is recorded on the magnetic recording medium by the fixed magnetic field. Here, since the recorded non-waveform data is recorded to a deeper layer of the medium than the data by the normal write current, the old data is completely erased. afterwards,
When the control unit commands each unit to write data, the current setting unit resets a normal write current value in the current drive unit, and data writing according to write data from the outside is executed.

In the third aspect of the present invention, the control unit commands each unit to erase the old record data from the portion on the medium where the write data should be recorded, immediately before the command to record the write data. . Then, the write data is always recorded immediately after the data of the corresponding portion is erased.

In the invention according to claim 4 or 5, when the current setting section sets the current value for writing or erasing in the current drive section, the setting control means sets the desired current value from the current value storage means. Read out and set the read out value in the current driver.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS.

The floppy disk device shown in FIG. 1 includes a magnetic head 6 for writing data on an arbitrary magnetic recording medium (medium) 51, a current drive unit 1 for applying a write current to the magnetic head 6, and the write operation. A current setting unit 2 that sets the magnitude of the current and a control unit (not shown) that controls the operation of each of these units are provided. In this embodiment, the magnetic head 6 records data on the medium 51 by applying a write current to the coil.

The current drive unit 1 outputs a drive current for generating a magnetic field to the magnetic head 6 according to the write data 52 received as a voltage pulse from the outside based on the current value set by the current setting unit 2. Further, the current driver 1 has a function of applying a DC current for erasing data to the magnetic head 6 when the current setting unit 2 sets a current value larger than the current used for normal data writing. There is. In the present embodiment, the output of the DC current is performed by the current setting unit 2 setting a current value larger than that at the time of writing and the non-waveform data being input as the write data 52 from the outside. Here, the current driver 1 is configured as a one-chip IC (R / W_IC).

The current setting unit 2 is based on a current value storage means 4 for storing in advance a current value for writing or erasing data set in the current driving unit 1, and a command for writing or erasing data from the control unit. And a setting control unit 5 for setting the current value stored in the current value storage unit 4 in the current drive unit 1. The output stage of the current value storage means 4 is equipped with a RAM (random access memory) 3 for temporarily holding a predetermined current value read from the current value storage means 4 by the setting control means 5, and the RAM 3 is equipped with the RAM 3. The held current value is set in the current driver 1. In this embodiment, the current value storage means 4 is an EEPROM,
The optimum current value for writing data and the optimum current value for erasing data are stored in advance. The current value for data erasing is set to a value that is reasonably larger than the current value for data writing. It has been decided. Further, the setting control means 5 is a microcomputer (CPU), which reads a current value for data writing from the current value storage means 4 when receiving a data writing command from the control unit and reads R.
When the data is set to AM3 and a data erasing command is received from the control unit, it has a function of reading the current value for data erasing from the current value storage means 4 and setting it in the RAM3. As a result, the current setting unit 2 realizes a function of setting a larger current value in the current driving unit when erasing data than when writing data. Here, the command from the control unit is transmitted by the control signal 7.

The control unit analyzes the command received from the host device and recognizes the data write command, and when the data write command is recognized, the control unit determines the address on the medium 51 to which the data should be written. A function of outputting an instruction to erase old record data of an address to each unit and inputting non-waveform data as write data 52 to the current drive unit 1, and a function of outputting new record data to the same address after each unit completes the data erasing operation. It has a function of outputting a writing command to each unit. Each of these functions is realized by sequentially executing a micro program equipped in the control unit.

Next, the operation of this embodiment will be described.

When the entire device is set to the operating state and the control unit recognizes a data write command from the host device,
The control unit determines the address on the medium 51 to which the data should be written, and outputs an instruction to erase the old record data 60 at the address to each unit. Upon receiving this command, the setting control means 5 reads the current value for erasing data from the current value storage means 4 into the RAM 3. The current value read out to the RAM 3 which is larger than that at the time of writing is set in the current driver 1, and when the current driver 1 receives the non-waveform data (write data 52) by the function of the controller, the magnetic head 6 receives the waveform data. A DC current for erasing data is applied. Then, the magnetic head 6 generates a fixed magnetic field in the coil, which is larger than that during normal data writing, and magnetizes the medium 51 to a deep layer. Therefore, the old recording data 60 recorded as a magnetic change on the medium 51 as shown in FIG. 2A is masked in a state where there is no magnetic change as shown in FIG. It will be erased.

When the erasing of data is completed in this way, the control section then outputs an instruction to write the new recording data 70 to the address where the old recording data 60 has been erased. Upon receiving this command, the setting control means 5 reads the current value for writing data from the current value storage means 4 into the RAM 3, and the current value for erasing data held in the RAM 3 until then becomes the current value for writing data. It will be reset. This RAM3
A current value smaller than that at the time of erasing the data read out is set in the current drive unit 1 as it is, and according to the normal write data input to the current drive unit 1, the magnetic head 6
An electric current is applied to. Therefore, the magnetic head 6 generates a magnetic field smaller than that at the time of erasing data to magnetize the medium 51,
As a result, data recording is performed.

As described above, according to the present embodiment, the current setting unit 2 sets a larger current value in the current driving unit 1 when erasing data than when writing the data, and the current driving unit 1 also causes the current Since the direct current is applied to the magnetic head 6 with a value, the old recording data 60 recorded on the magnetic recording medium 51 can be erased to a deep layer, and the old recording data 70 is read when the overwritten new recording data 70 is read thereafter. The inconvenience of noise caused by the data 60 can be effectively prevented. Further, since the control unit has a function of instructing each unit to erase the old recording data 60 of the data writing portion before writing the new recording data 70, before writing the new recording data 70, the old unit always writes the old recording data 70. Since the recorded data 60 is erased, it is possible to prevent the generation of noise due to the influence of the old recorded data 60 during the operation of the apparatus, and it is possible to effectively suppress the data read error. Further, regarding the current setting unit 2, an EEPROM is used as the current value storage unit, and the setting control unit 5
Since it is configured to read the current value from the EEPROM,
The electric current value set in the electric current drive unit 1 can be quickly changed by electric control.

Here, in the present embodiment, the current setting unit 2 is configured to store the current value at the time of writing and erasing data in advance, but the current driving unit 1 holds the current value for data writing and erases the data. At times, the current setting unit 2 causes the current drive unit 1 to
A configuration may be adopted in which the current value is increased by applying a bias to.

[0025]

Since the present invention is constructed and functions as described above, according to this, the current setting unit sets a larger current value in the current driving unit when erasing data than when writing data. Since the current drive section applies a direct current to the magnetic head with the current value, the old recording data recorded on the magnetic recording medium can be erased to a deep layer, and when the overwritten new recording data is read out thereafter. It is possible to effectively prevent the inconvenience of causing noise due to old recorded data, and thus it is possible to significantly reduce data read errors, and it is possible to provide a highly reliable data writing method and a floppy disk device. .

According to the second aspect of the invention, since the control section has a function of instructing each section to erase the old record data in the data write section before writing the new record data, the new record is performed. The old recorded data is always erased before writing the data, and it is possible to prevent the generation of noise due to the influence of the old recorded data throughout the operation of the device, which effectively suppresses the data read error. be able to.

Further, in the invention according to claim 3 or 4, since the setting control means is configured to read out the current value stored in advance from the current value storage means, the current value set in the current drive section can be quickly controlled by electric control. It is possible to secure the effective processing speed of the device.

As described above, according to the present invention, it is possible to provide an unprecedented excellent data writing method and a floppy disk device using this method.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

2 is a diagram for explaining a data write operation according to the embodiment shown in FIG. 1, FIG. 2 (a) shows a medium in which old data is written by another floppy disk device having a poor OW characteristic, and FIG. ) Indicates a state in which the old data is erased by the embodiment shown in FIG.

FIG. 3 is a configuration diagram showing a conventional example.

FIG. 4 is a diagram showing a recording state of a medium on which data is recorded by a conventional example, and FIG. 4A shows a state in which data is written by a floppy disk device having poor OW characteristics.
(B) shows a state in which data is overwritten by a floppy disk device having a good OW characteristic.

[Explanation of symbols]

 1,53 Current drive unit 2 Current setting unit 3 RAM 4 Current value storage unit 5 Setting control unit 6,54 Magnetic head 7 Control signal 8 Data erasing 51 Magnetic recording medium (medium) 52 Write data 55 Resistor 60 Old recording data 70 New record data

Claims (5)

[Claims] 1. A floppy disk device that applies a predetermined write current to a magnetic head to write data to an arbitrary magnetic recording medium, wherein the write current is applied to the magnetic recording medium before the data is written to the magnetic recording medium. A method for writing data in a floppy disk device, characterized in that the old recorded data in the data writing portion is erased in advance with a large current value. 2. A magnetic head, a current drive section for applying a write current to the magnetic head, a current setting section for setting the magnitude of the write current in the current drive section, and control for controlling the operations of these sections. And a current setting unit having a function of setting a larger current value in the current driving unit when erasing data than when writing data, and the current driving unit writes data by the current setting unit. A floppy disk device having a function of applying a DC current for erasing data to the magnetic head when a current value larger than that of time is set. 3. The floppy disk according to claim 2, wherein the control unit has a function of instructing each of the units to erase the old recorded data in the data writing portion before writing the data. apparatus. 4. The current setting unit, a current value storage unit that stores in advance a current value for writing or erasing data set in the current driving unit, and a command for writing or erasing data from the control unit. 3. The floppy disk device according to claim 2, further comprising: setting control means for setting the current value stored in the current value storage means in the current driver based on the above. 5. The rewritable EE is stored in the current value storage means.
The floppy disk device according to claim 4, wherein the floppy disk device is a PROM.