Portable computer hard disk protective reflex system

• US 5,227,929 A
• Filed: 11/26/1990
• Issued: 07/13/1993
• Est. Priority Date: 11/26/1990
• Status: Expired due to Term

• Current Assignee: Hitachi Global Storage Technologies Netherlands BV (Western Digital Corporation)
• Original Assignee: International Business Machines Corporation
• Inventors: Comerford, Liam D.
• Primary Examiner(s): Psitos, Aristotelis
• Assistant Examiner(s): KAPADIA, VARSHA A
• Application Number:
  US07/618,192
• Time in Patent Office: 960 Days
• Field of Search: 360/75, 371/4
• US Class Current: 360/75
• CPC Class Codes: G06F 11/004 Error avoidance G06F11/07 and subgroups take precedence
• CPC Class Codes: G11B 19/043 by detecting a free-fall condition
• CPC Class Codes: G11B 21/12 Raising and lowering; Back-spacing or forward-spacing along track; Returning to starting position otherwise than during transducing operation
• CPC Class Codes: G11B 33/08 Insulation or absorption of undesired vibrations or sounds
• CPC Class Codes: G11B 33/10 Indicating arrangements; Warning arrangements G11B15/04, G11B19/04, G11B27/34, G11B27/36 take precedence
• CPC Class Codes: G11B 5/5582 system adaptation for working during or after external perturbation, e.g. in the presence of a mechanical oscillation caused by a shock

Abstract

A protective reflex system for a portab1e computer hard disk initiates protective action before the hard disk suffers the shock of an impact in the event they fall from, for example, a user'"'"'s lap. A three axis accelerometer is mounted in the portable computer. The output of the accelerometer is continuously monitored by a dedicated processor. In the event of an acceleration event within a preset range of values, the dedicated processor passes a high priority interrupt to the central processing unit of the portable computer and then proceeds to park the disk heads. Alternately, the interrupt routine of the central processing unit may also cause the park operation. In addition to park operation, a brake operation may be performed by either the dedicated processor or the central processing unit.

Claims

1. A protective reflex system for a portable computer hard disk which initiates protective action before the hard disk suffers the shock of an impact, said hard disk having at least a one head flying above at least one motor driven rotating disk and said portable computer having a central processing unit, said protective reflex system comprising:

a three axis accelerometer mounted in the portable computer and generating signals proportional to accelerations along three axes; and

a dedicated processor for continuously monitoring said accelerometer signals and computing an acceleration vector, said dedicated processor further comparing a scaler value of said acceleration vector to a preset range of values close to IG corresponding to a free fall condition and passing a high priority interrupt to the central processing unit of the portable computer when said scaler value falls within said preset range;

one of said dedicated processor or said central processing unit calling a routine to park said at least one head of the hard disk rapidly before the hard disk suffers the shock of an impact.

2. The protective reflex system recited in claim 1 wherein one of said dedicated processor or said central processing unit further calls a routine to brake the rotation of said hard disk.

3. The protective reflex system recited in claim 2 wherein said dedicated processor calls the routine to park said at least one head of the hard disk rapidly while said central processing unit calls the routine to brake the rotation of said hard disk, said routines being processed simultaneously in parallel by said dedicated processor and said central processing unit.

4. The protective reflex system recited in claim 1 wherein said hard disk further has a frame and said accelerometer is mounted on said frame.

5. The protective reflex system recited in claim 1 wherein said dedicated processor calls the routine to park said at least one head of the hard disk rapidly.

6. A reflective method for protecting a portable computer hard disk by initiating protective action before the hard disk suffers the shock of an impact, said hard disk having at least a one head flying above at least one motor driven rotating disk and said portable computer having a central processing unit and being further provided with a three-axis accelerometer and a dedicated processor, said reflective method comprising the steps of:

monitoring by said dedicated processor signals from said accelerometer proportional to accelerations along three axes;

computing by said dedicated processor an acceleration vector and comparing a scaler value of said acceleration vector to a preset range of values close to IG corresponding to a free fall condition and passing a high priority interrupt to the central processing unit of the portable computer when said scaler value exceeds said preset range; and

parking by said dedicated processor or said central processing unit said at least one head of the hard disk rapidly before the hard disk suffers the shock of an impact.

7. The reflexive method recited in claim 6 further comprising the step of braking by one of said dedicated processor or said central processing unit the rotation of said hard disk.

8. The reflexive method recited in claim 7 wherein said step of parking said at least one head of the hard disk rapidly is performed by said dedicated processor while said step of braking the rotation of said hard disk is performed by said central processing unit, said steps being performed simultaneously in parallel by said dedicated processor and said central processing unit.

9. The reflexive method recited in claim 6 wherein said step of parking said at least one head of the hard disk rapidly is performed by said dedicated processor.