JPH01229467A - Floppy disk device - Google Patents

Abstract

PURPOSE:To improve the rewrite characteristics with a low-density medium by varying the damping constant of a write circuit in response to the recording density of the medium or a track. CONSTITUTION:The output of an OR gate 7 is equal to '0' with a low-density medium together with an analog switch 4 turned off, and the damping resistance limited to a resistance R2 only. While a parallel synthetic resistance of resistances R1 and R2 serves as a damping resistance with a high-density medium. Thus the damping constant is increased with the low-density medium and the rise time is improved since the write current has the proper overshoot. Then the rewrite characteristic which are affected by the rise of the rewrite current can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a floppy disk device, and particularly to a write circuit.

[Conventional technology]

The damping constant of the write circuit of a conventional floppy disk device is constant, and even when the recording density changes depending on the medium, the absolute value of the write current is changed, but the damping constant is not changed.

Furthermore, although the absolute value of the write current was changed in response to changes in recording density due to tracks, the damping constant was not changed.

[Problem to be solved by the invention]

In the conventional floppy disk device mentioned above, the damping constant of the writing circuit is constant, so changes in recording density depending on the writing medium or track must be taken into account in terms of rewriting characteristics (override characteristics). had not been done.

When writing with the same magnetic head, the rewrite characteristics will be different between low-density media and high-density media, with the low-density media usually being worse. Therefore, conventional floppy disk devices have the disadvantage that the rewrite characteristics of low-density media are worse than those of high-density media.

Furthermore, even when writing to the same medium with the same magnetic head, the recording density is different between the outer track and the inner track, so the rewrite characteristics will be different, and the outer track is usually worse. be. Therefore, conventional floppy disks have a drawback in that the rewriting characteristics of the outer tracks are worse than those of the inner tracks.

[Means to solve the problem]

The floppy disk device of the present invention is characterized in that it includes a write damping constant switching circuit that changes the write damping constant from large to small depending on the recording density of the medium.

〔Example〕

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

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

The output of a recording density detector 1 or an external recording density signal (DENSITY signal) 2 indicating the recording density of the medium is connected via an OR gate 7 to an analog switch 4 in a write damping switching circuit 3. analog switch 4
is ON when the input logic is ``l'' and OFF when the logic is ``0''
This is the result. Resistors R1 and R2, which serve as damping resistors that determine the vibration mode of the write current, are connected between the magnetic head 5 and the write circuit 6.

In the case of a low density medium, the output of the OR gate 7 becomes "0", the analog switch 3 is turned off, and the only damping resistance is the resistor R2. In a high-density medium, the parallel combined resistance of resistors R1 and R2 becomes a damping resistance. Therefore, in a low-density medium, the damping constant is large, and the write current has an appropriate overshoot, which improves the rise time and improves the rewrite characteristics, which are affected by the rise of the write current.

FIG. 2 is a block diagram of another embodiment of the invention.

Track counter 7 receives step signal 8 from the host system.
and a direction signal 9 indicating in which direction the magnetic head is to be moved, the switching signal C, which is the output of the track counter 7, has a logic value of ``1'''' on the inner periphery of a preset track. The switching signal C is connected to an analog switch 4 in the write damping switching circuit 3. The analog switch 4 is turned ON when the input logic is 0'1, and OFF when the input logic is 0'.

The operation of the damping switching circuit 3 is the same as that explained with reference to FIG. The rewrite characteristics, which are affected by the rising edge, will be improved.

〔Effect of the invention〕

As described above, the present invention has the effect of improving the rewriting characteristics of low-density media, which were conventionally poor, by making the damping constant in the write circuit variable depending on the recording density of the medium or track.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of one embodiment of the present invention, and Section 2 is a block diagram of another embodiment of the present invention. 1... Recording density detector, 2... External recording density signal,
3... Write damping switching circuit, 4... Analog switch, 5... Magnetic head, 6... Write circuit, 7... Track counter, 8... Step signal, 9... Direction signal .

Claims (1)

[Claims] A floppy disk device comprising a write damping constant switching circuit that changes the write damping constant in accordance with the recording density of the medium.