JPH0310189B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a seek control circuit for positioning a head at a target position on a disc-shaped rotating recording medium.
In particular, the present invention relates to a seek control circuit that controls a head positioning operation using an error signal between reference speed data or reference position data and a position signal obtained from a dedicated servo surface.

(b) Background of the Technology A storage device having a disk-shaped rotating recording medium requires a seek operation to position the recording/reproducing head at a target position on the disk-shaped rotating recording medium at high speed and with high precision.

On the other hand, the data recording density on disk-shaped rotating recording media has improved, and even for those that conventionally required large recording media, for example, those with a recording capacity of 100 Mbytes or less can now be recorded on a small recording medium of about 5 inches. I am now able to record.

As described above, it has become necessary for the seek control circuit in a storage device having a small-sized recording medium to have the same function as the conventional one but in a size commensurate with the small-sized recording medium.

(c) Prior Art and Problems As data recording density has improved and recording media as small as 5 inches have come into use, controlling the positioning of recording/reproducing heads has become a more important function than before.

Conventional seek control methods for positioning a recording medium at a target position at high speed and with high precision include: (1) having a dedicated servo surface and creating an analog speed signal from the analog position signal obtained from the servo surface; Similarly, there is a dedicated servo method that controls the speed based on the error from the reference speed of the analog signal, and (2) a dedicated servo method that does not have a dedicated servo surface but obtains a position signal from the servo signal written discretely on the data surface to control the speed or position. There is a sector servo method, and the dedicated servo method (1) requires a huge amount of circuitry because it is all analog processed (the technology for highly integrating analog signals has not yet been sufficiently developed, and integration is difficult. The sector servo method (2) has the disadvantage that high-speed control is not possible because servo signals can only be obtained discretely.

(d) Purpose of the Invention The object of the present invention is to provide a novel seek control circuit that eliminates the above-mentioned drawbacks, and in particular provides a high-speed seek operation control circuit with a small amount of circuitry in a storage device having a dedicated servo surface. The purpose of this invention is to realize a seek control circuit that makes it possible.

(e) Structure of the Invention The present invention has a dedicated servo surface for positioning the head at a target position on a disc-shaped rotary recording medium, and a position obtained from reference speed data or reference position data and the dedicated servo surface. a seek control circuit for controlling a head positioning operation based on a signal, the seek control circuit comprising: a first means for counting pulses indicating passage of a track on the disc-shaped rotary recording medium; a second means for converting an analog signal into a digital signal, an output of a memory holding the reference speed data or reference position data, an output of the first means, and an output of the second means; A third means for outputting a difference from the reference speed data or reference position data as an error signal, and a fourth means for converting the output of the third means into an analog signal, the third means: Calculate the actual speed by dividing the difference between the reference speed corresponding to the actual position data read from the memory, the actual data position in the previous counting cycle, and the current actual data position by the counting cycle time, and calculate the actual speed. The seek control circuit is characterized in that it outputs an error signal and performs the head positioning operation based on the output of the fourth means, thereby making it possible to control the seek operation at high speed with a small amount of circuitry. It can be achieved.

(f) Examples of the invention The present invention will be explained below with reference to the drawings.

FIG. 1 is an embodiment of the seek control circuit of a storage device according to the present invention, FIG. 2 is a control waveform diagram in FIG. Figures and B show diagrams of control situations due to errors from the reference speed, respectively.

In the figure, 1 is a servo head, 2 and 3 are amplifier circuits, 4 is a position signal generation circuit, 5 is a track passing pulse generation circuit, 6 is an analog/digital converter (hereinafter referred to as an A/D converter), and 7 is a pulse generator. Counting circuit, 8 is microprocessor (hereinafter referred to as MPU)
9 is a memory circuit (ROM), 10 is a digital/analog converter (hereinafter referred to as a D/A converter), and 11 is a voice coil motor drive circuit (hereinafter referred to as a VCM drive circuit).

In addition, in FIG. 2, the analog position signal (position signal waveform) used in the present invention is the track passing pulse, a is the waveform for forward seek control, (,
) and b indicate negative direction seek control waveforms (,), respectively. In addition, the vertical axis in FIG. 3A is the seek position, the horizontal axis is the seek time, c is the reference position curve, d is the actual position curve, and the vertical axis in FIG. 3B is the seek speed, the horizontal axis is the seek position, e represents a reference speed curve, and f represents an actual speed curve.

This embodiment includes a servo head 1 that reads servo data magnetically recorded on the servo surface (not shown) of a recording medium, and an amplifier circuit (preamplifier) that converts the magnetic servo data read by the servo head 1 into an electrical signal. ) 2. Amplifier circuit (automatic gain control amplifier) 3 which amplifies the output of amplifier circuit (preamplifier) 2 and outputs a signal with a constant width. Servo head 1 reads from the output signal of amplifier circuit (automatic gain control amplifier) 3. position signal generation circuit 4 that generates a position signal; position signal generation circuit 4;
a track passing pulse generation circuit 5 which generates a track passing pulse indicating the track passed by the servo head 1 from a position signal from the servo head 1; an A/D converter 6 which A/D converts the position signal and outputs it to the MPU 8;
The pulse counting circuit 7 that counts and stores track passing pulses and the reference data stored in the memory circuit (ROM) 9 are compared with the actual data read from the A/D converter 6 or the pulse counting circuit 7.
An MPU 8 outputs and controls an error signal that drives the VCM to the D/A converter 10, a memory circuit (ROM) 9 that stores reference position data or reference speed data, and a VCM drive circuit 1 that outputs the output of the MPU 8.
D/A converter 1 that performs D/A conversion to multiply by 1
0, by the output signal from the D/A converter 10
It consists of a VCM drive circuit 11 that drives the VCM.

Next, the operation of this embodiment will be explained.

In response to a seek operation command from a host device (not shown), the VCM (not shown) starts moving from the stop position to the movement target position. The signal read out by the servo head 1 during movement is amplified by amplifier circuits 2 and 3, and the position signal of the position read by the servo head 1 is amplified by the position signal generation circuit 4.
A track passing pulse generation circuit 5 generates a track passing pulse for each track passed by the servo head 1.

The position signal is converted into a digital signal by the A/D converter 6 and then read into the MPU 8. Track passing pulses are counted and stored in the pulse counting circuit 7 and read into the MPU 8.

In the case of control using the reference position data shown in FIG. 3A, the MPU 8 uses the reference position data stored in the memory circuit (ROM) 9 and the actual position data read above (position signal and track passing pulse).
Comparison control is performed to output an error signal between the reference position data and actual position data every counting cycle of MPU8,
This is D/A converted to drive and control a VCM (not shown).

In the case of control using the reference speed data shown in Figure 3B, the MPU 8 uses the reference speed corresponding to the read actual position data (position signal and track passing pulse), the actual data position from the previous MPU 8 counting cycle, and the current data position. The actual speed is calculated by dividing the difference from the actual data position by the counting cycle time, and an error signal with respect to the reference speed is output, which is D/A converted to drive and control the VCM (not shown).

In this embodiment, the movement from the center position of the disk-shaped recording medium toward the outer circumference is called positive direction seek a, and the movement from the outer circumference direction toward the center position is called negative direction seek b.
Judging by MPU8.

(g) Effects of the Invention According to the above-described present invention in which the seek control portion is digitalized, there is an effect that it is possible to provide a seek control circuit that is miniaturized through integration and is capable of high-speed seek movement control. .

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of a seek control circuit for a storage device according to the present invention, FIG. 2 shows a control waveform diagram in FIG. 1, and FIG. 3 shows a control situation diagram. In the figure, 1 is a servo head, 2 and 3 are amplifier circuits, 4 is a position signal generation circuit, 5 is a track passing pulse generation circuit, 6 is an A/D converter, 7 is a pulse counting circuit, 8 is an MPU, and 9 is a memory. circuit, 10
11 indicates a D/A converter, and 11 indicates a VCM drive circuit, respectively.

Claims (1)

[Scope of Claims] 1. A device having a dedicated servo surface for positioning the head at a target position on a disk-shaped rotating recording medium, and controlling the head based on reference speed data or reference position data and a position signal obtained from the dedicated servo surface. A seek control circuit for controlling a positioning operation, the circuit comprising a first means for counting pulses indicating passage of a track on the disk-shaped rotating recording medium, and converting an analog signal obtained from the dedicated servo surface into a digital signal. a second means for converting the reference speed data or the reference position data, the output of the memory holding the reference speed data or the reference position data, the output of the first means, and the output of the second means; a third means for outputting a difference with the position data as an error signal; and a fourth means for converting the output of the third means into an analog signal; Calculates the actual speed by dividing the difference between the reference speed corresponding to the actual position data, the actual data position in the previous counting cycle, and the current actual data position by the counting cycle time, and outputs an error signal with respect to the reference speed. . A seek control circuit characterized in that the head positioning operation is performed by the output of the fourth means.