JPS59180809A - Floppy disk driver - Google Patents

Abstract

PURPOSE:To reduce the load of a host computer and to ensure smooth reading of information by switching the filter function of filter circuit when a track position detecting means detects that a magnetic head reaches the track position set previously. CONSTITUTION:When a magnetic head 4 reads out information at track positions 0-39, the read information is supplied to a signal processing circuit 16 via the 1st and 2nd LPF13 and 14 and delivered to a host computer. When the head 4 reads out the information at the maximum track positions 40-, the read information by-passes the LPF14 with a field effect transistor 15 and supplied to the circuit 16 via the LPF13 only to be delivered to the host computer. In such a way, a track counter 22 detects the track position of the head 4 and switches the filter function of a filter circuit. Thus the load of the host computer is reduced, and at the same time the information can be smoothly read out.

Description

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

[Technical background of the invention and its problems]

A floppy disk drive device holds a floppy disk on a spindle rotated by a motor and controls its rotation.A carrier with a magnetic head mounted thereon is moved in the radial direction of the floppy disk using a gurus motor to transfer information to the floppy disk. Writing and reading are performed. Such a flow/pid disk drive device is connected to a post combiner, and commands from the post combiner control motor rotation, If information, etc.
Read control 11 is performed. By the way, the 70T disk drive device is equipped with a filter circuit to cut out noise and output accurate information when reading information, and the filter circuit has two types of filter functions with different characteristics. For example, the filter function used is switched between when reading information from the inner track and when reading information from the outer track. Conventionally, floppy r
In disk drive devices, the filter function of the filter circuit was switched by a switching signal from the host computer. In other words, when the host computer reads out an error from a floppy disk drive, it outputs a switching signal to the drive to switch the filter function of the filter circuit and read out the same information again. In this case, the same information has to be read twice when the host computer is switched, resulting in a problem of a delay in reading the information.

[Purpose of the invention]

The present invention has been made to solve these problems, and an object of the present invention is to provide a 70 disk drive device that can completely reduce the burden on a host computer and can read information smoothly.

[Summary of the invention]

By bringing the magnetic head mounted on the carrier into contact with the rotating floppy disk, and moving the carrier in the radial direction of the floppy disk using a pulse motor, each truck 1. A floppy disk drive device that writes and reads information to and from a magnetic head has two types of filter functions with different characteristics that can be switched and used, and is provided with a filter circuit that allows at least read information to pass through, so that the magnetic head can move to a preset track position. The filter function of the filter circuit is switched when the track position detecting means detects that the track position has been reached.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1 and FIG. 2, a floppy disk 3 is held on a spindle 2 which is rotationally driven by a motor 1. The floppy disk 3 is provided with a long hole 5 along its radial direction for bringing the Ii magnetic head 4 into contact with the disk medium 3a. 6 is an index hole from which an index signal is taken out. The magnetic head 4 is provided at the tip of the carrier 8 which moves at +f4 at 7a and 7b.
The J7 disk 30 is movable in the radial direction. A presser body 9 for holding the disk medium 3a is provided on the opposite side of the magnetic head 4 so as to be movable up and down and placed on the carrier 8. As shown in FIG. 3, a light shielding plate 10 is provided on one side of the carrier 8 in a protruding manner,
When the magnetic head 4 is located at the zero track position (located at the outermost layer) of the disk medium 3a, the light shielding plate 10 connects the light emitting diode I1m and the phototransistor Ilb that constitute the zero track position detector 11. It is set to block light. The carrier 8 is connected to the shaft 7g via a belt etc. by the base motor 12.
Movement is controlled on r7b.

FIG. 4 is a circuit diagram of the main part, in which eleventh and second low/4' filters 13 and 14 with different characteristics are provided, and the first low/4' filter is provided with
The output terminal of the low-noise filter 13 is connected to the input terminal of the second low-noise filter 140, and the P-channel field effect transistor 15 is connected in parallel between the input and output terminals of the second low-noise filter 14. A filter circuit is provided. Then, the information read out in the magnetic field 4 is inputted to the first low-panel filter 13. Said second
The output terminal of the low-pass filter 14 is connected to the signal processing circuit 1
It is connected to the power terminal of 6. The signal processing circuit 16 is controlled by a host computer (not shown) and outputs read information to the host computer.

A light emitting diode lla is connected through a resistor 17 between the +V terminal and ground, and a phototransistor llb is connected through a resistor 18. The collector output of the phototransistor llb is supplied to the negative input terminal B of the monostable circuit 21 for resetting the counter via the output amplifier 19 and the inverter 20. The monostable circuit 21 resets the track counter 22 in response to the fall of the input to the input terminal B. The track counter 22 is formed by serially connecting two up/down counters 22, 222, and is, for example, a 7-digit binary counter. This track counter 22 is controlled up and down based on a direction signal DIR that determines the moving direction of the carrier 8.
When moves inward of the floppy disk 3, DI
When R=1 and the counters 221 and 222 count up, and the carrier 8 moves outward from the floppy disk 3, DIR=O and the counter 522 counts up.
1.222 counts down. The track counter 22 counts the step signal STP generated each time the carrier 8 moves one track inward or outward. The track counter 22 is set in advance, for example, “
A count value discrimination circuit 23 is provided which detects the counting of zero "°39"'40" and detects the track position of the magnetic field 4, and together with the track counter 22 forms a track position detecting means. The count value discrimination circuit 23 is a zero value discrimination circuit 231."39' value discrimination circuit 2
32 and "40" and "40" value path 233.

The output of the count value discrimination circuit 23 is supplied to a filter switching control circuit 24 as switching control means for switching the filter function used by the filter circuit. The filter switching control circuit 24 is operated by FRI1. Pfrog 241 is provided,
The zero value discrimination circuit 231 and the "39" value discrimination circuit 232 are connected to the reset input terminal R of the FurinozoFrozzo 24.
Input the output of 1 through the OR gate 25 and
．． Connect the above "40" to the set input terminal S of Zoflop 24.
The output of the value discrimination circuit 233 is input. The flip-flop 241 transmits its reset output terminal power to the field effect transistor 15 through a puffer amplifier 242.
supplies to Dart.

In the embodiment of the present invention configured as described above, the carrier 8
moves toward the outside of the 70-tube disk 3, and the light-shielding plate 10 just touches the light-emitting diode 11h and the phototransistor ll.
Monostable circuit 2 for counter reset when located between
1 is operated, thereby resetting each counter 221, 222 of the track counter 22. At this time, the shift flip 70 knob 241 is reset again by the output of the zero value discrimination circuit 23, and the field effect transistor 15 is controlled to be turned off. Also, at this time, the magnetic head 4 on the carrier 8 is exactly at the zero track position of the disk medium 3a.

In this state, the master pulse motor 12 is operated and the magnetic head 4 is
When moved toward the inner circumference of the floppy disk 3, DIR
= 1, the track counter 22 becomes magnetic, and de 4 becomes 1.
Each time the truck moves inward, the step signal STP is counted up. And the track counter 22 is "39"
``When the track position is counted,'' 39 ``the value discrimination circuit 232 outputs an irregular signal, but since the flip-flop 241 has already been reset, there is no change.Subsequently, the track counter 22 becomes ``40''.
When counting the rack position, “40” value discrimination circuit 233
A high level signal is output from the flip-flop 241
is set. As a result, the viewing field effect transistor 15 is turned on. From then on, this state is maintained as long as the track counter 22 counts the track position in the range from "40" to the maximum track position.After that, the magnetic head 4 may move to the rack position (39"). Flip-flop 241 is reset again and field effect transistor 15 is turned off. In this state, the track counter 22 is at a track position in the range of 0" to "39".
It is retained as long as ff is not counted.

Therefore, when the magnetic head 4 reads out one green bulletin at tracks "o" to "39", the read information is sent to the signal processing circuit 16 via both the first and second low-pass filters 13 and 14. is manually input and output to the host computer.

Further, when the magnetic head 4 reads information at a position of 40'' to the maximum 1. ) The signal is input to the signal processing circuit 16 only via the low-pass 7 filter 13 and output to the host computer.

In this way, the outer tracks from '0'' to '39'' and '40
The filter function of the filter circuit can be switched depending on the inner circumferential track of ~, and processing such as noise cutting can be performed according to the circumferential speed, etc. In this way, the track position of the magnetic helad 4 can be detected by the track counter 22. Since the filter function of the fill circuit is switched by the filter function, the conventional trouble of the host computer detecting an error in the information, outputting a filter switching signal, and reading the information again is eliminated, reducing the burden on the host computer. The information can be read out smoothly.

Next, another embodiment of the invention will be described with reference to the drawings.

Components that are the same as those in the embodiment described above are given the same reference numerals and detailed explanations will be omitted.

As shown in FIG. 5, instead of a track counter, this is a relatively wide light-shielding device that always blocks light from the light-emitting diode 11 & to the phototransistor Ilb when the magnetic head 4 is on the "0" to "39" track. Plate 101 to carrier 8
In this device, the circuit may be configured so that the 7-lip float 24 is reset, set, or turned off by the rise or fall of the collector output of the phototransistor llb.

By doing so, the track counter and count value discrimination circuit can be omitted. In this case, the same effects as in the above embodiment can be obtained.

Note that the light shielding plate 10 is replaced with the light shielding plate 101.
″) May be done using a microswitch operated at the rack location.

〔Effect of the invention〕

As described in detail above, according to the present invention, it is possible to provide a 70-tubi disk drive device that can reduce the burden on the host computer used for control and can read information smoothly.

[Brief explanation of drawings]

1 to 4 show an embodiment of the present invention. FIG. 1 is a plan view of the main part, FIG. 2 is a side view of the main part, and FIG. 3 is the configuration of the track zero position detection section. FIG. 4 is a circuit diagram of a main part, and FIG. 5 is a plan view of a main part showing another embodiment of the present invention. 3... Floppy disk, 4... Magnetic head, 8...
... Carrier, 10 ... Light shielding plate, 11 ... Track zero position detector, J 3 ... First low-pass 7-ilter, 14 ... Second low-pass filter, 15 ... -N field effect Transistor, 22...Track counter, 23
...Count value discrimination circuit, 24-filter switching control circuit.

Claims (3)

[Claims] (1) By bringing a magnetic head mounted on a carrier into contact with a rotating floppy disk and moving the carrier in the radial direction of the floppy disk using a pulse motor, information can be written and read on each track.
It has two types of filter functions with different characteristics that can be switched and used in floppy disk drive devices that perform
a filter circuit that allows at least read information to pass; track position detection means that detects that the magnetic head has reached a preset track position; and use of the filter circuit in response to a detection output from the track position detection means. A floppy disk drive device comprising a switching control means for switching a filter function. (2) The track position detection means is formed by a track counter that counts the track position of the magnetic head, and a count value determination circuit that determines whether or not the count value of this track counter has reached a set value. A floppy disk drive device according to claim 1, characterized in that: (3) The floppy disk drive device according to claim 1, wherein the track position detecting means is formed of a photo sensor for detecting the moving position of the carrier.