IP Library › Granted Patent US 7,423,830
Granted Patent B2
US 7,423,830 · App. 11/401,047 · Granted Sep 9, 2008

Detecting head/disk contact in a disk drive using a calibration parameter

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 7,423,830
App. No.
11/401,047
Granted
Sep 9, 2008
Kind
B2
Abstract

A disk drive having a heater element on the read/write head includes control circuitry to prevent head/disk contact by limiting power to the heater element. As the power to the heater element increases, thermal expansion reduces the fly height until head/disk contact occurs. During drive calibration, a maximum power level allowed to the heater element is determined by detecting heater power at a level where a parameter value such as motor current exceeds a threshold level.

Claims (9)

1. A method for detecting head/disk contact in a disk drive having a head with a heater element including a heater power and a heat power level, and a motor for driving the disk drive, the disk drive having a motor current value, comprising: establishing a motor current threshold level; increasing heater power; comparing a motor current value to the motor current threshold level; and recording a contact heater power level when the motor current value exceeds the motor current threshold level.

2. The method of claim 1 , further comprising generating a head/disk contact condition when the motor current value exceeds the motor current threshold level.

3. The method of claim 1 , further comprising positioning the head above a calibration track prior to increasing the heater power.

4. The method of claim 1 , further comprising identifying first contact point after detecting head/disk contact.

5. The method of claim 1 , further comprising performing disk drive calibration and storing the contact heater power level during disk drive calibration.

6. The method of claim 1 , further comprising modifying the contact heater power level based upon environmental factors.

7. A disk drive having a motor for driving the disk drive, the disk drive having a motor current value and a motor current threshold level, comprising: a head having a heater element; a data storage disk; and control circuitry which prevents head/disk contact by limiting power to the heater element to a maximum value determined during drive calibration by detecting heater power at a level where the motor current value exceeds the motor current threshold level.

8. The disk drive of claim 7 , wherein the maximum value is determined using a calibration track of the data storage disk.

9. The disk drive of claim 7 , wherein the control circuitry adjusts the maximum value of the power to the heater element based on environmental factors.

Assignments (10)
RELEASE OF SECURITY INTEREST IN PATENTS PREVIOUSLY RECORDED AT REEL/FRAME (045455/0001) Recorded May 20, 2022
From: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., AS NOTES COLLATERAL AGENT
To: DELL MARKETING CORPORATION (SUCCESSOR-IN-INTEREST TO ASAP SOFTWARE EXPRESS, INC.); DELL MARKETING L.P. (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO CREDANT TECHNOLOGIES, INC.); DELL USA L.P.; DELL INTERNATIONAL L.L.C.; DELL PRODUCTS L.P.; DELL MARKETING CORPORATION (SUCCESSOR-IN-INTEREST TO FORCE10 NETWORKS, INC. AND WYSE TECHNOLOGY L.L.C.); EMC CORPORATION (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO MAGINATICS LLC); EMC IP HOLDING COMPANY LLC (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO MOZY, INC.); SCALEIO LLC
Reel/Frame 061753/0001 →
RELEASE OF SECURITY INTEREST IN PATENTS PREVIOUSLY RECORDED AT REEL/FRAME (040136/0001) Recorded Apr 26, 2022
From: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., AS NOTES COLLATERAL AGENT
To: DELL MARKETING CORPORATION (SUCCESSOR-IN-INTEREST TO ASAP SOFTWARE EXPRESS, INC.); DELL MARKETING L.P. (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO CREDANT TECHNOLOGIES, INC.); DELL USA L.P.; DELL INTERNATIONAL L.L.C.; DELL PRODUCTS L.P.; DELL MARKETING CORPORATION (SUCCESSOR-IN-INTEREST TO FORCE10 NETWORKS, INC. AND WYSE TECHNOLOGY L.L.C.); EMC CORPORATION (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO MAGINATICS LLC); EMC IP HOLDING COMPANY LLC (ON BEHALF OF ITSELF AND AS SUCCESSOR-IN-INTEREST TO MOZY, INC.); SCALEIO LLC
Reel/Frame 061324/0001 →
RELEASE OF SECURITY INTEREST Recorded Nov 3, 2021
From: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH
To: ASAP SOFTWARE EXPRESS, INC.; AVENTAIL LLC; CREDANT TECHNOLOGIES, INC.; DELL USA L.P.; DELL INTERNATIONAL, L.L.C.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL SOFTWARE INC.; DELL SYSTEMS CORPORATION; EMC CORPORATION; EMC IP HOLDING COMPANY LLC; FORCE10 NETWORKS, INC.; MAGINATICS LLC; MOZY, INC.; SCALEIO LLC; WYSE TECHNOLOGY L.L.C.
Reel/Frame 058216/0001 →
SECURITY AGREEMENT Recorded Apr 22, 2020
From: CREDANT TECHNOLOGIES INC.; DELL INTERNATIONAL L.L.C.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL USA L.P.; EMC CORPORATION; FORCE10 NETWORKS, INC.; WYSE TECHNOLOGY L.L.C.; EMC IP HOLDING COMPANY LLC
To: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.
Reel/Frame 053546/0001 →
SECURITY AGREEMENT Recorded Mar 21, 2019
From: CREDANT TECHNOLOGIES, INC.; DELL INTERNATIONAL L.L.C.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL USA L.P.; EMC CORPORATION; FORCE10 NETWORKS, INC.; WYSE TECHNOLOGY L.L.C.; EMC IP HOLDING COMPANY LLC
To: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.
Reel/Frame 049452/0223 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 29, 2016
From: EMC CORPORATION
To: EMC IP HOLDING COMPANY LLC
Reel/Frame 040203/0001 →
SECURITY AGREEMENT Recorded Sep 21, 2016
From: ASAP SOFTWARE EXPRESS, INC.; AVENTAIL LLC; CREDANT TECHNOLOGIES, INC.; DELL USA L.P.; DELL INTERNATIONAL L.L.C.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL SOFTWARE INC.; DELL SYSTEMS CORPORATION; EMC CORPORATION; EMC IP HOLDING COMPANY LLC; FORCE10 NETWORKS, INC.; MAGINATICS LLC; MOZY, INC.; SCALEIO LLC; SPANNING CLOUD APPS LLC; WYSE TECHNOLOGY L.L.C.
To: THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A., AS NOTES COLLATERAL AGENT
Reel/Frame 040136/0001 →
SECURITY AGREEMENT Recorded Sep 21, 2016
From: ASAP SOFTWARE EXPRESS, INC.; AVENTAIL LLC; CREDANT TECHNOLOGIES, INC.; DELL USA L.P.; DELL INTERNATIONAL L.L.C.; DELL MARKETING L.P.; DELL PRODUCTS L.P.; DELL SOFTWARE INC.; DELL SYSTEMS CORPORATION; EMC CORPORATION; EMC IP HOLDING COMPANY LLC; FORCE10 NETWORKS, INC.; MAGINATICS LLC; MOZY, INC.; SCALEIO LLC; SPANNING CLOUD APPS LLC; WYSE TECHNOLOGY L.L.C.
To: CREDIT SUISSE AG, CAYMAN ISLANDS BRANCH, AS COLLATERAL AGENT
Reel/Frame 040134/0001 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Feb 18, 2010
From: IOMEGA CORPORATION
To: EMC CORPORATION
Reel/Frame 023953/0328 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 10, 2006
From: MA, YIPING; THAYNE, MARK
To: IOMEGA CORPORATION
Reel/Frame 017748/0508 →