JPH02273384A - Track cross signal generating circuit - Google Patents

Abstract

PURPOSE:To shorten the seeking time and at the same time to ensure the stability even to the external noises by using a window signal produced from a head moving speed signal, and extracting only the genuine track cross signal out of those uncorrected ones. CONSTITUTION:An AND circuit 8 secures an AND between a window signal (b) serving as a gate signal produced from a head moving speed signal 1 and an uncorrected track cross signal 3 produced from a track error signal. The output of the circuit 8 is applied to an input terminal of a one-shot pulse forming circuit 9, and a genuine track cross signal is outputted to an output terminal 4 from the output terminal of the circuit 9. When an integration circuit 5 is reset by a switch 10, the head moving speed signal 1 is integrated to generate the voltage proportional to the distance equal to the movement of the head. As a result, the seeking time is shortened and at the same time the stability is ensured to the external noises.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a track cross signal generation circuit in a head positioning circuit of a disk storage device.

[Conventional technology]

Conventionally, in a head positioning circuit for a high-speed, large-capacity disk storage device, in order to move the head and position it on a target track, it is necessary to count the number of tracks that the head traverses in the radial direction of the medium during seek. For this reason, conventionally, a track cross signal is generated by detecting a zero cross point of a track error signal.

[Problem to be solved by the invention]

The conventional track cross signal generation circuit described above detects the zero cross point of the track error signal that occurs all the time from the start to the end of seek, and uses this as the track cross signal. That is, even if the track error signal is disturbed in the preformat section or the like and an extra zero cross point is generated, this will be generated as a track cross signal. Therefore, there is a drawback that this disturbance increases the seek time to access the target track. Furthermore, the conventional track cross signal generation circuit has the disadvantage that the track error signal is disturbed by external noise.

SUMMARY OF THE INVENTION An object of the present invention is to provide a track cross signal generation circuit that detects only true track cross signals to shorten seek time and operates stably even in the face of external noise.

[Means to solve the problem]

The track cross signal generation circuit of the present invention generates a track cross signal from a track error signal in order to position the head on an arbitrary target track of a disk storage device, and the head movement speed signal is input to the track cross signal generation circuit. an integrator circuit that integrates the output of the integrator circuit, a comparator that compares the output of the integrator circuit and a reference voltage, an A, N D circuit that takes the logical product of the output of the comparator and the uncorrected track cross signal, and an output of the AND circuit. a one-shot pulse forming circuit that creates a one-shot track cross signal by inputting the
and a switch means for resetting the integrating circuit under the control of a track cross output signal from the shot pulse forming circuit.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a track cross signal generation circuit diagram showing one embodiment of the present invention.

As shown in FIG. 1, this embodiment has an integrating circuit 5 which inputs and integrates a head movement speed signal 1. This integrating circuit 5 consists of a resistor R, a capacitor C and an operational amplifier 11.
The output terminal is connected to the input terminal of the buffer 6. This buffer 6 connects its output to one input terminal,
It functions to take out only the voltage from the integrating circuit 5.

Comparator 7 compares the output of buffer 6 with reference voltage 2 and outputs a window signal. In this embodiment, an AND circuit 8 calculates the logical product of a window signal as a gate signal created from a head speed signal 1 and an uncorrected track cross signal 3 created from a track error signal.
I take it more seriously. The output of the AND circuit 8 is applied to the input terminal of the one-shot pulse forming circuit 9, and a true track cross signal is outputted from the output terminal to the output terminal 4. Further, the output terminal of this one-shot pulse forming circuit 9 is configured to reset the integrating circuit 5 connected to both ends of the integrating capacitor C. That is, the integration time Fl+
5 is reset by a switch 10, the head moving speed signal 1 is integrated to generate a voltage proportional to the distance the head has moved.

Now, the speed detection gain of the head is k t CV/ (m/
s)], the track pitch is Tp (m), and if the integrating circuit 5 is reset at the moment of track crossing during head seek, then the output voltage of the integrating circuit 5 is V at the next track crossing. is C, which is a constant that is unrelated to the magnitude of the moving speed of the head.

Therefore, by appropriately selecting reference voltage 2,
The comparator 7 can generate a window signal that goes high just before the next track crossing.

This situation will be explained with reference to FIG. 2 below.

FIG. 2 is a signal waveform diagram of each part of the track cross signal generation circuit in FIG. 1.

As shown in FIG. 2, an uncorrected track cross signal (2) is created based on the track error signal (1). On the other hand, the integral output a shown in (3) and the Ref voltage are compared by the comparator 7, and the output is the window signal b.
By using (4) as a gate signal, the output pulse (5), which is a true track cross signal, can be extracted from the uncorrected track cross signal (2) and output from the output terminal 4.

Here, in FIG. 2, part A surrounded by a dotted line is a part where the tracking error signal (1) is disturbed by noise. In the conventional circuit, a false track cross signal B is generated, but in this embodiment, as shown in (3), since the output a of the integrating port 1285 in the section A is not lower than the reference voltage, That is, since the window signal is at a low level, no false track cross signal is generated.

In this way, the track cross signal generation circuit of this embodiment can output a track cross signal only at a true track cross position.

In short, in this embodiment, a gate signal that predicts the timing at which the head crosses the track during the seek time is created from the head movement speed signal, and only the zero-cross point of the track error that occurs within the gate is generated as the track cross signal. Therefore, the seek time can be shortened and it can be stabilized against external noise.

〔Effect of the invention〕

As explained above, the track cross signal generation circuit of the present invention extracts only the true track cross signal from the uncorrected track cross signal using the window signal created from the head movement speed signal, thereby improving the tracking of the track during seek. Since cross signals can be counted accurately, there is no need to perform extra seek operations during positioning, which has the effect of shortening seek time and stabilizing against external noise. .

[Brief explanation of drawings]

FIG. 1 is a diagram of a track cross signal generation circuit of a head showing an embodiment of the present invention, and FIG. 2 is a signal waveform diagram of each part of the track cross signal generation circuit in FIG. 1... Head speed signal (input terminal), 2... Reference voltage terminal), 3... Uncorrected track cross signal (input terminal), 4... Track cross signal (output terminal), 5 ...Integrator circuit, 6...Baatufa, 7.
... Comparator, 8... AND circuit, 9... One-shot pulse forming circuit, 10... Switch, a...
Integral output, b... Comparator output (window signal)
.

Claims (1)

[Claims] A track cross signal generating circuit that generates a track cross signal from a track error signal in order to position a head on an arbitrary target track of a disk storage device includes: an integrating circuit that inputs and integrates the head movement speed signal; and the integrating circuit. a comparator that compares the output of the comparator and a reference voltage, an AND circuit that takes a logical product of the output of the comparator and the uncorrected track cross signal, and a one that inputs the output of the AND circuit to create a one-shot track cross signal. A track cross signal generating circuit comprising: a shot pulse forming circuit; and a switch means controlled by a track cross output signal from the one shot pulse forming circuit to reset the integrating circuit.