JPS611299A - Drive circuit of floppy disk device - Google Patents

Abstract

PURPOSE:To electrically correct a periodic feeding pitch error by controlling the phase current ratio of a pulse motor. CONSTITUTION:Correcting resistors 11-14 for regulating the exciting currents are inserted between transistors 2-5 for driving phase coils 7-10 to select the resistance values of the resistors 11-14 to cancel the feeding pitch error at the stopping position in phase exciting period due to the unbalance of the exciting currents. Thus, the periodic feeding pitch error of a pulse motor or the like can be electrically corrected to improve the carriage feeding pitch error.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a floppy disk device (hereinafter abbreviated as FD device), and particularly to an improvement in a pulse smoke drive circuit for feeding the head carriage.

<Prior art> Conventionally, as a pulse smoke drive circuit of an FD device, the fourth
A circuit as shown in the figure is known.

Upon input of the DIR signal indicating the direction of movement of the head and the 5TEP signal, which is a movement command, the control circuit 1 outputs a signal multiplied by vH for a predetermined time, turns on the transistor 6, and supplies 12V to the drive circuit.
Apply a voltage of Each phase coil of 4-phase pulse motor /I/
7 to 10 are suitably driven by transistors 2 to 5 for 2-2 excitation drive in accordance with output signals A, A, B, and B of the control circuit 1, and head feeding is performed. After a predetermined period of time has elapsed, the transistor 6 is turned off, and the pulse motor is maintained at the stopped position at a voltage of 5.5 cm (the on state of the last combination is maintained).

Such a drive circuit does not take into account the stop position error of the pulse motor itself. For example, if a feed mechanism is configured with one trunk and one step, the cycle of four trunks, as shown in FIG. In other words, a feed pinch error occurs that repeats in the phase excitation period.

As another example, if a 4-phase motor with 24 steps/rotation is configured with a feed mechanism of 1 trunk - 4 steps, as shown in Part 6, there will be 6 trunk cycles, that is, the motor rotation period (1 rotation - 6 tracks). This causes repeated feed pitch errors.

Note that FIGS. 5 and 6 are illustrative, and the feed pitch error shown in the figures is not taken within one cycle, and each pulse motor can take any feed pinch error.

Here, it is only shown that the feed pitch error is repeated every cycle (4 tracks or 6 tracks).

These pitch errors are due to unbalance of each phase coil of the pulse motor itself, mechanical dimensional errors of the nutator and rotor, magnetic unbalance, etc., and mechanical precision of the rotation-linear conversion mechanism.

As described above, the conventional drive circuit has a drawback in that the feed pitch error of the pulse motor or the like directly appears in the carriage feed error.

Although FIG. 4 shows a unipolar drive circuit, a bipolar drive circuit also has the same drawbacks.

<Object of the Invention> An object of the present invention is to provide a drive circuit that electrically corrects the periodic feed pitch error of pulse motors, etc., which is the drawback described above, and improves the Gihe Ridge feed pitch error. .

<Example> FIG. 1 shows an embodiment of the present invention.

FIG. 1 shows a 4-phase 2-2 excitation unipolar drive, 11-rack=1 step drive circuit.

Each phase coil 7~10 and drive 1-rough foot 22~
5, a correction resistor 11~ for adjusting the excitation current, respectively]
4 is inserted, and the resistance value of each correction resistor 11 to 14 is selected so as to cancel out the feed pitch error at each stop position within the phase excitation period due to unbalance of the excitation current.

FIG. 2 shows a second embodiment.

Figure 2 shows a 4-phase 2-2 excitation bipolar drive, 11 to 1 step drive circuit, and similarly, the resistance value is set to cancel each feeding pinch error within the 4"I" excitation cycle. Resistors 11 to 14 are inserted.

FIG. 3 shows a third embodiment.

Figure 3 shows a drive circuit with 4-phase 2-2 excitation unipolar drive, 24 steps/rotation, Il-rank-4 steps (61-rack/rotation), and each track stop has 1-state IQ.
ff';l' In the control circuit 1, A and B are ON, and A.

π is controlled to be OFF. Here, A in phase with A a
``A small output is provided, and depending on the loaf position of the pulse motor, the transistor 2'' with the correction resistor 11 inserted or the transistor 2 without the correction resistor 11 is switched.

That is, at the stop position where the pitch error is large, A' is selected and output, and the A-phase excitation' (fi f
By correcting M, the pitch j! at that position is corrected. :
j Compensate for the difference. At the stop position where the error is small, the normal A is set, and the pitch error of one rotation period is corrected as a whole.

If a circuit is provided to select each resistance corresponding to each stop position (six positions), the accuracy will be even higher. According to the present invention, as shown in FIG. Ill 'tun rhi It 6 system 61
(By doing 1, you get 11 sleeves, and various +; r
)] Can be widely published in Shishimi, especially in FD (Do1 no Autumn 1)
-7 It is effective in reducing the number of blackheads.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram showing one embodiment of the present invention, Fig. 2 is a circuit diagram showing another embodiment, Fig. 3 is a circuit diagram showing still another embodiment, and Fig. 4 is a conventional example. The circuit diagrams, FIGS. 5 and 6 are characteristic diagrams for explaining the feed pitch error shown in FIG. 1, respectively. ]...Control circuit, 2~5.2'...Phase excitation transistor, 7~10 Coil, 11~14...
Correction resistance. Representative '1) 41 people Patent attorney Aihiko Fukushi (and 2 others)
Figure l Figure 2 +12V +5V 12V Dimension 5V Figure 4 Figure 5 Figure 6

Claims (1)

[Claims] 1. Correct the head carriage feed pitch error in the pulse motor drive circuit for head carriage feed.
A drive circuit for a floppy disk device, comprising means for controlling a phase current ratio of a pulse motor.