JPS6297101A - Floppy disk drive device - Google Patents

Abstract

PURPOSE:To obtain an inexpensive floppy disk drive device which has the interchangeability with a conventional device by securing such a constitution where the information is recorded or reproduced in a half cycle period from the starting time points of the 1st and 2nd index signals in response to a side selection signal. CONSTITUTION:The 1st index signal and the 2nd index signal having a 180 deg. phase shift between them are supplied to an index signal selecting circuit 9. Then the 1st index signal emerges at an index signal output terminal 8 when the side selection signal applied to a side selection terminal 3 is set at 'H'. While the 2nd index signal emerges at the terminal 8 when the side selection signal is set at 'L' respectively. A floppy disk 21 is revolved at 1/2 conventional speed and a floppy disk device counts the timing from the generating time point of the index signal to perform the recording and reproduction. Thus it is possible to record the information on both conventional sides A and B on a single track.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a floppy disk drive device that is inexpensive and compatible with conventional devices.

(Prior Art) In recent years, floppy disk drive devices are equipped with two sets of magnetic heads in order to record and reproduce information on both sides of a floppy disk. It is common to provide a side select circuit for selectively connecting these heads to a recording circuit or a reproducing circuit.

(Problems to be Solved by the Invention) The above configuration requires two sets of expensive magnetic head components and a side select circuit.
The disadvantage was that the equipment was expensive.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a floppy disk drive device that overcomes the drawbacks of the prior art and is inexpensive and compatible with conventional devices.

(Means for Solving the Problems) The floppy disk drive device of the present invention rotates a floppy disk, sets concentric tracks at predetermined pitches, and records and reproduces information on a floppy disk. a first index signal generating circuit that generates one single pulse per rotation of the floppy disk in response to the rotation of the floppy disk; and a single pulse that is 180 degrees out of phase with the first index pulse in response to the first index pulse. a second index signal generation circuit that generates a second index signal; and an index signal selection circuit that selects a first index signal and a second index signal in response to a side select signal and outputs the selected index signal as an index signal; , information is recorded or reproduced in a half-circle section of the floppy disk from the time point at which the first index signal is generated and in a half-circle section from the point at which the second index signal is generated.

(Function) With the above configuration, the information that was conventionally recorded and reproduced on two tracks, side A and side B, is made into one track, that is, the information on side A is recorded in a half-circle period from the time when the first index signal is generated. The information on side B is recorded and reproduced in a half-circle period from the time when the second index signal is generated. Therefore, only one set of magnetic head components is required, and a complicated side switching circuit is not required.

(Example) An example of the present invention will be described based on FIGS. 1 and 2.

FIG. 1 is a block diagram of a floppy disk drive device according to the present invention. In the figure, reference numeral 1 denotes a first index signal, which is composed of a photocoupler or the like placed opposite to the south side of the index window of the floppy disk, and generates a single pulse (first index signal) once per rotation of the floppy disk. A generation circuit 2 is a second index signal generation circuit to which the first index signal generated by the first index signal generation circuit 1 is applied and generates a single pulse (second index signal) 180 degrees out of phase therefrom; 3 is a side select terminal to which a side select signal is applied; 4 is an inverter circuit whose input terminal is connected to the side select terminal 3; 5 is an inverter circuit whose input terminal is connected to the side select terminal 3; and 5, the side select terminal 3 is connected to one input terminal, and the first 6 is a NAND circuit to which the output terminal of the index signal generation circuit 1 is connected, one input terminal of which is the output terminal of the inverter circuit 4, and the other input terminal of which is connected to the output terminal of the second index signal generation circuit 2. The circuit 7 is an AND circuit whose two input terminals are connected to the output terminals of NAND circuits 5 and 6, respectively, and 8 is an AND circuit 7.
This is the index signal output terminal to which the output terminal of is connected.

The inverter circuit 4, the NAND circuit FH6, and the AND circuit 7 constitute an index l-number selection circuit 9.

FIG. 2 is a plan view of a floppy disk installed in a floppy disk drive.

In the figure, 21 is a floppy disk, 22 is a jacket of the floppy disk 21, 23 is an index window, 24 is an index hole, and 25 is a head window.

When the floppy disk 21 rotates and the index hole 24 passes through the index window 23, the first
An index signal generation circuit 1 generates a first index signal. The second index signal generated by the second index signal generation circuit 2 is 1 higher than the first index signal.
80 degrees out of phase. The first index signal and the second index signal are respectively supplied to the index signal selection circuit 9. When the side select signal applied to the side select terminal 3 is "HII", the first index signal and the side select signal are (ff L
In the case of II, the second index signal is applied to the index signal output terminal 8. Furthermore, floppy disk 21
rotates at the conventional speed of 172 as described above, and the floppy disk device measures the timing from the generation of the index signal to record and reproduce information, so when the side select signal is tt Htp, as shown in Figure 2 Recording and reproduction are performed on the left half of the floppy disk 21 shown by , and when the side select signal is It L 1', recording and reproduction is performed on the right half. In other words, the conventional side A and side B
information can be recorded and played back on one track.

(Effects of the Invention) According to the present invention, information for one track can be recorded and reproduced in a half-circle period from the time of signal generation, and there is no need to arrange two magnetic head components as in the conventional case. Without,
There is no need for a complicated side select circuit, and the cost can be greatly reduced, which has a great practical effect.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a floppy disk drive device according to an embodiment of the present invention, and FIG. 2 is a plan view of a floppy disk installed in the device. 1...First index signal generation circuit, 2...Second index signal generation circuit, 3...Side select terminal, 4...Inverter circuit, 5.6...NAND circuit, 7... AND circuit, 8... Index signal output terminal, 9... Index signal selection circuit, 21... Floppy disk, 22...
Jacket, 23... Index Wind, 2
4... Index hole, 25... Head wind. Patent applicant: Matsushita Electric Industrial Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] It rotates a floppy disk, which is a magnetic recording medium, and
a first index signal generating circuit which records and reproduces information by setting concentric tracks at predetermined pitches, and which generates one single pulse per rotation in response to the rotation of the floppy disk; , a second index signal generating circuit that generates a single pulse 180 degrees out of phase with the first index pulse in response to the first index pulse, and the first index signal and the second index signal in response to the side select signal. an index signal selection circuit which selects and outputs the second index signal as an index signal; A floppy disk drive device characterized in that it is configured to record or reproduce information in a half-circle section.