JPH03235205A - Floppy disk device - Google Patents

Abstract

PURPOSE:To prevent the superposition of noise components by taking out only the low-frequency component by a low-pass filter, inverting the phase thereof and using this component as a writing current. CONSTITUTION:The write data WD inputted to a write data input terminal 1 passes a flip-flop circuit 2 and is made into the digital signal having the same phase and frequency component as the phase and frequency component of the writing current waveform. This signal is branched and inputted to a write driver 3 and the low-pass filter 4. The output of the filter 4 is inputted to a write driver 5. The digital signal current and the low-frequency current selected by the filter 4 are generated in coils 8, 9 of a magnetic head 7 in the case when a write gate signal WG is set in a writing state at a write gate signal input terminal 6. The low-frequency spectra in the data signal are negated at the time of writing in the range below the cut-off frequency of the filter 4 by previously inverting the current phases of the coils 8, 9. The low-frequency spectra are thus not detected in the signal. The superposition of the noise components is prevented in such a manner.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a floppy disk device.

[Conventional technology]

As floppy disk devices have become smaller and have larger capacities in recent years, a tracking servo system for positioning the magnetic head is being considered. A deep servo method (embedded 5ervo) is a method of recording servo signals on a data surface and constantly obtaining servo signals. In this method, as shown in FIG. 2, the magnetic recording medium as a magnetic recording medium is composed of a magnetic layer surface layer portion 12, a DC erase area 13, and a magnetic layer deep layer portion 14 formed on a base film 11 facing a magnetic head 10. This method records servo signals in the deep part 14 of the layer 15 and data signals in the surface part 12. In order to read and write data while constantly reading out the servo signals, sectors and
Theoretically, it is expected that tracking accuracy will be improved compared to other methods such as servo.

[Problem to be solved by the invention]

In the conventional deep servo method described above, the reproduced output is obtained with a waveform in which both the servo signal and the data signal are superimposed.
If the data signal part contains several pits and several tens of bits of consecutive repeated data patterns, the spectrum of the reproduced output of the data signal part contains a large amount of components close to DC, so the data signal frequency is usually A low frequency component generated from a data signal is superimposed on a servo signal written at a low frequency of 1/10 or less, significantly deteriorating the tracking accuracy of the servo.

[Means to solve the problem]

The floppy disk device of the present invention includes a clip 7er tube circuit that divides write data into two frequencies, and a clip 7er tube circuit that divides write data into two.
It consists of a low-pass filter that filters the output of the three-tube circuit, a write driver that amplifies the power of the output of the low-pass filter, and a magnetic head that has a dedicated coil for flowing the output of the write driver.

[Effect]

In the present invention, only the low frequency components of the data pattern to be recorded are extracted using a low-pass filter, and the low frequency components contained in the data pattern to be recorded are extracted by inverting the phase and supplying it to a dedicated coil as a write current. components will be canceled out.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram of a 70-tubiy disk device according to an embodiment of the present invention. In the figure, write data WD input to a write data input terminal 1 passes through a flip-flop circuit 2 and is converted into a digital signal having all the same phase and frequency components as the write current waveform. These converted nine digital signals are branched and input to a conventionally used first light driver 3 and a low-pass filter 4, respectively, and the output of the low-pass filter 4 is input to a second light driver 5. . Here, when the write gate signal WG is set to the write state at the write gate signal input terminal 6, the @1 coil 8 and the second coil 9, which are respectively wound around the magnetic head 7, are in the conventional state. A digital signal current and a low-frequency sinusoidal current selected by the low-pass filter 4 are generated.

At this time, by inverting the phase of the current flowing through the first coil 8 and the second coil 9, the low-frequency spectrum contained in the data signal is kept within the cutoff frequency of the low-pass filter 4. This is canceled out during writing, and the low frequency spectrum is no longer detected in the written data signal, thereby significantly reducing malfunctions of the servo circuit.

〔Effect of the invention〕

As explained above, when the present invention records the entire repetitive data pattern of several pits and several tens of bits, the magnetic head extracts only the low frequency component using a low-pass filter and inverts the phase before recording the data signal. By supplying the other wound coil as a write current, the low frequency components contained in the recorded data pattern are canceled out, so that the aforementioned low frequency components are not included in the reproduced signal. This has the effect of preventing noise components from being added to the servo signal recorded at a low frequency.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the structure of a floppy disk device according to an embodiment of the present invention, and FIG. 2 is a sectional view showing the schematic structure of a conventional deep servo system. 1-...9 write data (WD) input terminal, 2...-
-Flip-flop circuit, 3...4th write driver, 4...low-pass filter, 5...2nd
Write driver, 6 @ e a a write gate signal input terminal, 7 fist...magnetic head, 8... fist, 1st
coil, 9...second coil.

Claims (1)

[Claims] It has a flip-flop circuit that divides the frequency of write data into two, a low-pass filter that filters the output of the flip-flop circuit, a write driver that amplifies the power of the output of the low-pass filter, and a coil that supplies the output of the write driver. A floppy disk device comprising a magnetic disk.