JPS63316377A - Track zero detector for floppy disk device - Google Patents

Abstract

PURPOSE:To obtain a device capable of being assembled and moreover performing a track zero detecting operation without fail by equipping a magnet disposed in a prescribed position of a carriage, a Hall element for detecting a magnetic field of the magnet and an outputting means for outputting a track zero detecting signal. CONSTITUTION:The Hall element 22 is so disposed as to output a high level signal when a magnetic head mounted on the carriage 11 moves to a position of, e.g., a track 2 on a disk, and to output a low level signal with a track 3. An output circuit 23 being an inner circuit of an FDMC outputs the track zero detecting signal when an output signal of the Hall element 22 is changed into the high level, and stops the output when that is changed into the low level. Consequently, a controller FDC is active while an exciter phase of a stepping motor 12 is zero phase, and when the track zero detecting signal is outputted from the output circuit 23, it decides that the magnetic head is positioned in the track zero on the disk. By this method, the FDC stops the stepping motor 12 in its drive via the FDMC, thus stopping the carriage 11 in its movement.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a track zero detection device for a floppy disk drive for detecting that a magnetic head is positioned at track zero.

(Prior Art) Conventionally, a floppy disk device is provided with various status detection devices 1ifl for detecting the status of a disk drive (FDD), one of which is a track zero detection device. The track zero detection device usually consists of a photo-interrupter (optical detector) 10, as shown in FIG.

By the way, the carriage 11 is operated by a stepping motor 12.
Due to the driving force of the main rail 14 and sub rail 15
It moves in the radial direction (arrow) of the magnetic recording medium (disk). The driving force of the stepping motor 12 is
It is transmitted to the carriage 11 by a steel belt t11413. The carriage 11 has a magnetic head mounted on its tip and moves over the disk.

The track zero detection device outputs a track zero detection signal when the detection piece 16 provided on the carriage 11 blocks the light from the photo inkluctor 10. The controller (FDC) determines that the magnetic head is located at track zero on the disk based on the track zero detection signal.

By the way, since the photo-interrupter 10 has unstable pointing properties, a minute position adjustment is required when the photo-interrupter 10 is attached. For this reason, the assembly process of the track zero detection device requires a lot of work time.
This causes a decrease in the efficiency of the entire assembly process.

(Problems to be Solved by the Invention) In the conventional track zero detection device, minute position adjustment is required at the time of installation, and a lot of work time is required. Therefore, there is a problem that the efficiency of the assembly process of the entire floppy disk device is reduced.

SUMMARY OF THE INVENTION An object of the present invention is to provide a track zero detection device for a floppy disk drive that can be installed with a simple assembly process and that can accurately detect track zero.

[Plus points of the invention] (Means and effects for solving the problems) The present invention includes a magnet disposed at a predetermined position of a carriage, a Hall element that detects the magnetic field of the magnet, and a track zero detection signal that is output. This is a track zero detection device equipped with an output means. The Hall element is a magneto-electric transducer that is placed at a predetermined position on the frame that constitutes the floppy disk drive body, and detects the magnetic field of the magnet when the magnetic head is positioned on the zero track of the magnetic recording medium due to carriage movement. be.

A device having such a configuration can be installed by a simple projecting process without requiring minute position adjustments in the photo-interrupter. Therefore, it is possible to improve the efficiency of the assembly process of the entire floppy disk device.

(Example) The present invention will be described in detail below with reference to the drawings. FIG. 1 is a perspective view showing the structure of the same embodiment. In FIG. 1, the track detection device consists of a Hall element 22 attached to a frame 21 of a 20° FDD magnet attached to a carriage 11 and an output circuit 23. The magnet 20 is placed at a predetermined position on the rear end of the carriage 11, that is, on the opposite side of the tip attached to the magnetic head.

When the magnet 20 approaches, the Hall element 22 detects the eye field of the magnet 20 and outputs a voltage signal as a detection signal. The output circuit 23 outputs a track zero detection signal to the FDC according to the detection signal of the Hall element 22.

Next, the operation of this embodiment will be explained. First, when a seek command to move the magnetic head to track zero is output from the host system (CPU), the FDD control 311 circuit (FDMC) outputs various ff1ll (lJ and other signals) for driving the carriage 11. As a result, the carriage 11 moves toward the outer periphery of the disk (in the direction of the arrow in FIG. The Hall element 22 detects the magnetic field of the magnet 20 and outputs a voltage signal according to the magnetic field.

Here, as shown in FIG. 2, the Hall element 22 outputs a high level signal when the magnetic head mounted on the carriage 11 moves to the position of track 2 on the disk, and outputs a low level signal at track 3. It is arranged to output a level signal. The output circuit 23 is an internal circuit of the FDMC, and outputs a track zero detection signal when the output signal of the Hall element 22 changes to a high level, and stops outputting when the output signal changes to a low level. In this case, for example, when the excitation phase of the stepping motor 12 is O phase, track 0, when it is 1 phase, track 1, when the excitation phase of the stepping motor 12 is O phase, track 1, when the excitation phase of the stepping motor 12 is the 2nd phase, track 2. When the excitation phase is the 3rd phase, the track 3, etc. The drive is controlled so that the track position of the magnetic head corresponds to that of the magnetic head. Therefore, when the excitation phase of the stepping motor 12 is the O phase and the track zero detection signal is output from the output circuit 23, the FDC determines that the magnetic head is located at track zero on the disk.

As a result, the FDC stops driving the stepping motor 12 through the FDMG, and stops the movement of the carriage 11.

In this way, the magnet 20 and the Hall element 22 can be used to reliably detect the trunk zero of the magnetic head. Here, when attaching the magnet 20 and the Hall element 22, the arrangement relationship can be determined in advance based on the characteristics shown in FIG. Therefore, it is possible to attach the photo-interrupter 10 by a simple operation without requiring minute position adjustment as in the case of using the conventional photo-interrupter 10. This simplifies the installation process of the track zero detection device and improves the efficiency of the process.

[Effects of the Invention] As described in detail above, according to the present invention, a floppy disk device can be assembled with simple work without requiring minute position adjustments during installation, and track zero can be detected reliably. A device that performs the operation can be realized. This makes it possible to improve the efficiency of the entire floppy disk device assembly process compared to the conventional method.

[Brief explanation of drawings]

Figure 1 is the book Fe! ! Carriage 1 related to the implementation side of J]
FIG. 2 is a characteristic diagram of the Hall element of the same embodiment, and FIG. 3 is a perspective view showing the configuration of a conventional carriage mechanism. DESCRIPTION OF SYMBOLS 11... Carriage, 12... Stepping motor, 20... Magnet, 21... Frame, 22...
...Hall element, 23...output circuit. Applicant's Representative Patent Attorney Takehiko Suzue District 1 Figure 2 Figure 3

Claims (1)

[Claims] By detecting the position of a carriage moving in the radial direction of the magnetic recording medium, a track zero detection signal is generated when the magnetic head mounted on the carriage is located at the zero track of the magnetic recording medium. A track zero detection device for an output floppy disk device includes a magnet placed at a predetermined position on the carriage, and a magnet placed at a predetermined position on a frame constituting the main body of the floppy disk device so that the magnetic head is moved by movement of the carriage. A Hall element that detects the magnetic field of the magnet when positioned at the zero track of the magnetic recording medium, and an output means that outputs the track zero detection signal based on the detection signal output from the Hall element. A track zero detection device for a floppy disk device.