JPS6369497A - Positioning device - Google Patents

Abstract

PURPOSE:To perform a high precision positioning at high speed by correcting object positions in going and returning strokes beforehand through learning a seek hysteresis. CONSTITUTION:A computing part 3 sets as a hysteresis amount a difference between off-track amounts in each track of going and returning strokes to compute going and returning microstep parameters. Said microstep parameters are stored in a storage part 4. This computing part 3 outputs from the storage part 4 a microstep parameter corresponding to a desired track on recording and regenerating. Said parameter is converted into an analog signal by a D/A converter 5 and this analog signal is further converted into a winding current by a drive circuit 6 to rotate a stepping motor 7.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a positioning device used in a device for magnetic recording and reproducing by moving a magnetic head onto a desired track.

2. Description of the Related Art Conventionally, in a magnetic recording/reproducing apparatus that moves a magnetic head onto a desired track on a magnetic disk, the rotation of a stemming motor is converted into linear movement to move (seek) the magnetic head. When performing this seek, the amount of movement relative to the number of steps of the motor when moving the magnetic disk from the inner circumference to the outer circumference and the amount of movement when moving the magnetic disk from the outer circumference to the inner circumference do not match as shown in FIG. This discrepancy occurs due to backlash during reciprocation of the transmission system and misalignment of the center of the magnetic disk.

Therefore, in conventional positioning devices, positioning has been performed using one of the following three methods.

(1) A method that does not correct 7-Q hysteresis using an open loop.

(2) A method to prevent seek hysteresis from occurring by always seeking from one side.

(3) A method of repositioning using servo information after completing the seek.

Problems to be Solved by the Invention However, the above conventional positioning method using a stepping motor has the following problems. In a method that does not correct seek hysteresis using an oven loop, positioning accuracy becomes an obstacle to increasing density. 1. In the method of always seeking from one direction, the seek time itself is included in the settling time (7tring time) of the transient vibration after the seek, and that time must be lengthened. Furthermore, the method of realigning the position after seeking has a problem in that it takes an extra amount of time.

The present invention solves these conventional problems,
It is an object of the present invention to provide a positioning method using a stepping motor that can perform high-accuracy positioning at high speed.

Means to Solve the Problems In order to achieve the second object, the present invention performs a round-trip seek before recording and reproducing to learn the seek hysteresis, and determines the destination position for going and returning in the calculation section. 9, a microstep seek is performed to that position, and after the seek is completed, high-precision positioning can be performed at high speed without repositioning.

Therefore, according to the present invention, since the seek hysteresis is corrected in advance by learning, it is possible to perform positioning with high accuracy and to perform positioning at high speed.

Embodiment FIG. 1 is a block diagram of a positioning device according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the operation according to the same embodiment. 1st
In the figure, 1 is an audio signal detection circuit that detects a servo signal recorded on the media, 2 is an A/D converter that converts the servo signal into a digital signal, and 3 is a calculation section. The microstep parameter for the round trip is calculated using the difference between the amount of off-track on each track in the going journey and the amount of off-track in each track on the return journey as a hysteresis amount, and this microstep parameter is stored in the storage unit 4. be. The calculation section 3 outputs microstep parameters corresponding to a desired track from the storage section 4 during recording and reproduction. 5 is a D/A converter that converts this microstep parameter into an analog signal, 6 is a drive circuit that converts this analog signal into a winding current, and 7 is a stepping motor that rotates according to the winding current of the cigarette. The stepping motor 7 moves the magnetic head onto a desired track via rotational linear motion conversion means.

Next, the operation of this embodiment will be explained.

In FIGS. 1 and 2, the servo signal detection circuit 1 reproduces the servo signal recorded on the medium by performing one to several reciprocating seeks. The calculation unit 3 uses this servo signal A.
/ Input via the D converter 2, and calculate the off-track amount in each track on the forward journey and the off-track amount on each track on the return journey using the following method as hysteresis amount, and calculate the microstep parameters for the going and returning. decide. This microstep parameter is
(1) Using the microstep parameters of the forward stroke as a reference, when seeking in the return stroke, the hysteresis Δα shown in FIG. 2 is regarded as a constant value and added to the reference parameter as an offset.

(2) If △α cannot be regarded as a constant value, due to its tendency to change, for example, Δα equal to the number of phases of a stepping motor
Add the value to the reference parameter as an offset.

(3) Separate parameter tables are provided for the microsteps for the outgoing process and the return process.

Calculated using methods such as

These calculation results are stored in the storage unit 4, and during subsequent seek, the corrected microstep parameters are outputted corresponding to the desired track.

This microstep parameter is the D/A converter 5
This converts the signal into an analog signal, which is input to the drive circuit 6, and applied to the stepping motor 7 as a winding current to correct the amount of hysteresis.

Effects of the Invention As is clear from the above embodiments, the present invention has the following effects.

(1) Since the seek hysteresis is learned,
This amount is corrected, allowing highly accurate positioning.

(2) Since the seek hysteresis is learned and taken into the calculation section, and the microstep parameters are calculated before the actual seek, it is possible to seek directly to the desired positioning position, resulting in short seek times. be able to.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a positioning device according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the operation of the same embodiment. DESCRIPTION OF SYMBOLS 1... Servo signal detection circuit, 2... A/'D converter, 3... Arithmetic unit 1, 1... Storage unit, 5... D/A converter, 6... Drive circuit , 7...Stepping motor. Name of agent: Patent attorney Satoshi Nakao and one other person Figure 1

Claims (1)

[Claims] A servo signal detection circuit that detects the servo signal recorded on the media, an A/D converter that converts this servo signal into a digital signal, and a hysteresis system that calculates the difference in off-track amount for each track in the round trip from this digital signal. a calculation unit that calculates a reciprocating microstep parameter as a quantity and outputs a microstep parameter corresponding to a desired track during recording and reproduction; a drive circuit that converts the microstep parameter into an analog signal and outputs it as a winding current; A positioning device including a stepping motor that inputs this winding current and moves the magnetic head to a desired track via a rotational linear movement conversion means.