JPS62112266A - Index detecting device - Google Patents

Abstract

PURPOSE:To eliminate an index timing from the change due to temperature and voltage, to stabilize timing of an index signal, to obtain a correct adjusting time and to secure interchangeability by providing a digital index adjusting circuit to an index circuit of an FD device. CONSTITUTION:The pulse inputted from an index sensor 21 enters an adjusting time deciding circuit 23, and the output of the counter circuit, in which the internal counter circuit starts to operate by the signal of the reference signal (about 7.8kHz), is inputted to the next separating circuit. According to the setting conditions of a pin switch 22, the output gate of the separating circuit is selected, the adjusting timing is determined, by the gate, the index signal waveform is outputted, enters an FD device control circuit 24 and the control of the reading and the writing is executed. Thus, the digital adjusting circuit is used, the adjusting time is set by the pin switch, and therefore, the index timing can be correctly adjusted without being influenced by the change of the temperature and the voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an index detection device used in a floppy disk drive or the like to detect an index indicating a reference position at the start of reading or writing data on an n1 medium.

Conventional technology Fig. 4 (at is an 8-inch floppy disk, Fig. 4
bj is a 5-inch floppy disk, fc+ in Figure 4 is 3
．． It shows a 5-inch floppy disk. Figure 4 (
In discs like a) and (b), there is a hole (1) for the drive system, a window 2 for recording and reproducing data on the media, and an index hole that indicates the reference position at which reading and writing of data on the media begins. 3 was provided both on the media itself and on the case. Then, when this media is rotated by the drive system and the holes in the Daikichi case of the media themselves coincide, it is detected that the media is at its reference position.

Conventional 3.5 inch Flo, P disk device (hereinafter referred to as μF)
DD), as shown in Figure 4 (C1), the medium (hereinafter referred to as the medium) does not have an index hole, and the index is detected using a reflector plate 8a provided on the side of the spindle motor (hereinafter referred to as the D motor), a macnet, or other devices. By the method of
This is done using a photo sensor 18, a hall sensor, etc. The index indicates a reference position from which reading and writing of data on the medium begins in the FD device.

Next, the media chucking mechanism is shown in FIG. 4
5 is a metal hub, 5 is a disk, 6 is a shaft, 7 is a drive pin, 8 is a rotor, and 9 is a drive coil. The metal hub 4 and the disk 5 are the components of the media, and the chucking magnet 6 and the drive pin 7 are the components of the spindle hub, which is fixed to the D motor consisting of the rotor 8 and the drive coil 9. .

10 is a chucking hole, 11 is a driving pin,
12 is a positioning hole, 13 is a metal hub, and 14 is a spindle shaft.

In the above configuration, the metal hub 4 is attracted to the shaft of the spindle, the drive pin 11 enters the positioning hole 12 of the media, and the position of the media is fixed at a fixed location by the spindle shaft 14 and the drive pin 11. do. Since the positional relationship between the drive pin 11 and the reflector of the D motor is fixed at 90 degrees, the start position of reading and writing of the medium during clamping and the position of the reflector are fixed. However, when assembling the D motor, there is a possibility that the position of the reflector plate will be misaligned by ±0.5 degrees. For this reason, it is difficult to ensure compatibility with other drives, and it is important to ensure compatibility.

FIG. 7 shows a block diagram of index adjustment of a conventional FD device that solves the above problem. 15 is a sensor, 16 is a timer circuit (MM circuit), and 17 is a control circuit. To explain the operation, the input waveform from the index sensor 15 is adjusted by the timer circuit 16 configured by JC, and a signal enters the FD device control circuit (FDC circuit) ζζ to set the Read/Write timing.

In this manner, even with the conventional circuit configuration, by changing JC using the timer circuit 16, the index can be adjusted and compatibility between button devices can be ensured.

Problems to be Solved by the Invention However, in the index circuit of the conventional FD device described above, since a resistor and a capacitor are used in the configuration of the timer circuit, there is a phenomenon that the adjustment time changes due to fluctuations in temperature and voltage. The problem was that it was difficult to ensure compatibility between the two.

The present invention solves these conventional problems, and by replacing the JC timer circuit with a digital index adjustment circuit, the index signal is stabilized without being affected by temperature and voltage fluctuations, and the adjustment time is reduced. Excellent FD that ensures accuracy and compatibility
The purpose is to provide a device.

Means for Solving the Problems In order to achieve the above object, the present invention provides a digital index adjustment circuit in the index circuit of the FD device, eliminates fluctuations due to temperature and voltage, stabilizes the timing of the index signal, and reduces the adjustment time. This is to ensure accuracy and compatibility.

Effects The present invention has the following effects due to the above configuration. In other words, when the index pulse is input, the counter circuit in the adjustment judgment circuit changes to the reference frequency (approximately 7.8).
The operation is started by the signal G(z).

The output of the counter circuit is connected to a separator circuit, and the adjustment timing is determined by which output gate of the separator circuit is selected.

This output gate selection is done by a pin switch.

Then, an index output signal is output from the selected gate. By changing the setting of this pin switch, the adjustment time can be easily changed.

By digitally managing this adjustment time, variations due to temperature and voltage can be eliminated, accuracy can be achieved, and compatibility between FD devices can be ensured.

Example FIG. 1 shows the configuration of an embodiment of the present invention.

In FIG. 1, reference numeral 21 denotes an index sensor, which inputs an index signal through a reflective plate of a D motor using a reflective photocoupler. 22 is a pin switch. There are three switches 22, and eight settings can be made. Reference numeral 23 denotes an adjustment time determination circuit, which has a counter circuit and determines the index output timing based on the conditions and count number set by the pin switch. 24 is F
D is a device control circuit, and controls reading, writing, etc. based on the index output.

Next, the operation of the above embodiment will be explained. In Fig. 1, the pulse input from the index sensor 21 enters the adjustment time judgment circuit 23, and the internal counter circuit starts operating with a signal of the reference frequency (approximately 7.13 KHz).The output of the counter circuit is the next separate signal. input to the circuit. Then, the adjustment timing is determined by selecting the output gate of the separate circuit according to the setting conditions of the pin switch 22, and the index signal waveform is output from this gate, enters the FD device control circuit 24, and controls reading and writing. will be carried out.

Also, in this circuit, there are 3 pin switches and 8 settings, which means that the D motor's reflector attachment error is at most 555.
This is because the range is 6 (μS).

FIG. 2 is a circuit diagram of this embodiment. Each signal ζ will be explained with reference to FIG. The reference frequency signal 25 is a signal frequency-divided from the oscillator, and thereby the counter circuit 26
performs the count. The reset signal 27 becomes 'H' when the FD device is powered on, but becomes 'L' when the FD device becomes operational. The ready signal 28 indicates that reading and writing are possible, and if possible, '
H', otherwise it becomes 'L'. The drive selection signal becomes "L" if the FD device is in use, otherwise it becomes "H". In order to output the index here, the reset signal 27 is L', the ready signal 28 is 1H',
The drive selection signal 29 must be 'L'.

3H and (bj) are signal waveform diagrams corresponding to FIG. 2. In FIGS. , When the index provided on a part of the side of the D motor is detected, the index sensor input 3 is activated only for that time.
0 becomes "1". The counter circuit 26 has a reference frequency 25
When the counter circuit 26 counts up to the number set by the pin setter 22, the separator circuit 31 sends out a count end signal B and stops counting the reference frequency 25. Figure 3 (bj shows index output 3 due to short-circuit status of pin switches 1 to 3)
5 is shown.

The FD device control circuit 24 has an index output 35 of “1”.
” to “0” is the index reference position, and reading and writing to the floppy disk starts. In this manner, the pin setter 22 allows fine adjustment of the index reading timing to be easily and accurately performed.

Effects of the Invention As is clear from the above embodiment, the present invention uses a digital adjustment circuit and sets the adjustment time with a pin switch, so it can accurately index without being affected by temperature and voltage fluctuations. This has the effect of being able to adjust the timing.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an index detection device according to an embodiment of the present invention, FIG. 2 is a circuit diagram according to the same embodiment, FIG. (a
>, (b), (C) are front views of general 8-inch, 5-inch, and 3.5-inch floppy disks, No. 5
The figure is a side view of a general 3.5-inch floppy disk drive, Figure 6 is a diagram showing the media of a general 3.5-inch floppy disk and the stopped state of the drive, and Figure 7 is a side view of a general 3.5-inch floppy disk drive.
The figure is a block diagram of a conventional index detection device. 21... Index sensor, 22... Pin setter,
23...Adjustment time determination circuit, 24...FD device control circuit, 26...Counter circuit, 31...Separator circuit. Name of agent: Patent attorney Toshio Nakao (1st person)
Figure 2 Figure 3<b) Index Dragon 0 Quimin 7 Tayat Figure 4

Claims (1)

[Claims] A drive unit that magnetically records and reproduces information on a floppy disk, an index housed in the drive unit and provided at a predetermined position on the rotating body of the motor, and an index sensor that detects this index and sends out a signal only during detection. , a reference frequency generating means that sends out continuous pulses with a much shorter period based on the signal of this index sensor, a counter circuit that counts this reference frequency and outputs a counted value, and a settable pin setting device. a separator circuit that stops the pulse transmission of the reference frequency generating means when the counter circuit reaches the count value that has been reached, and an index output signal indicating that the counter circuit is counting, to detect the reference position of the floppy disk. F
An index detection device equipped with a D control circuit.