KR970050892A - Head Damage Prevention Circuit of Hard Disk Drive - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to voice coil motor control of a hard disk drive, and more particularly, to a head damage prevention circuit in order to prevent head damage due to a collision between mechanisms of a hard disk drive.

2. The technical problem to be solved by the invention

The present invention provides a head damage prevention circuit that can prevent head damage by preventing a collision between an actuator striker and a crash stopper or a striker and a magnetic latch that may occur during track tracking.

3. Summary of Solution to Invention

The present invention provides a hard disk drive including an actuator light emitting means and a photo sensor in an ID and an OD region capable of receiving light emitted from the light emitting means, by a parallax of a light receiving detection signal output from the photo sensor. By detecting the speed of the actuator and comparing the voltage level value proportional to the detected speed of the actuator with the reference voltage level value, when the voltage level value is lower than the reference voltage level, it is judged as the overspeed of the actuator to control the VCM driving unit. Prevent head damage from collision.

4. Important uses of the invention

Can be used for hard disk drives.

Description

Head Damage Prevention Circuit of Hard Disk Drive

Since this is an open matter, no full text was included.

5 is a detailed circuit diagram of the actuator speed detection unit 20 and the comparison unit 22 in FIG.

Claims (4)

In the head damage prevention circuit of a hard disk drive, an actuator speed detecting means which is present at a position of an actuator corresponding to an ID and an OD of a head and outputs a level value corresponding to a moving speed of the actuator, and the actuator speed detecting means. Comparison means for outputting different level values according to whether the actuator moving speed is abnormal by comparing the level value output from the reference level value with the reference level value, and controlling the movement of the actuator in response to the level value input from the comparing means. A head damage prevention circuit of a hard disk drive, characterized in that the control means. The method of claim 1, wherein the actuator speed detecting means is a pair of light emitting means attached to the actuator to move and the position of the actuator corresponding to the ID and OD of the head, respectively, and the time difference depending on whether the light receiving means is moved A photoelectric sensor for generating a pulse with an input, an RS flip-flop for inputting each pulse generated at a time difference from the pair of photosensors, and an output terminal connected between an output terminal of the RS flip-flop and a ground; And a capacitor for applying a voltage generated by integrating a logic level value outputted from the circuit by the time difference to a comparison means. The head of a hard disk drive according to claim 2, wherein the pair of photosensors is composed of two photosensors and is disposed at a certain distance from the positions of the actuators corresponding to the respective areas of the ID and the OD of the head. Damage prevention circuit. The head damage prevention circuit of a hard disk drive according to claim 1, wherein said control means stops the movement of the actuator in response to a logic level value input from said comparing means. ※ Note: The disclosure is based on the initial application.