Integrating control of slider bias potential, touch-down detection and fly-height determination in a HDD

• US 8,599,506 B2
• Filed: 12/31/2009
• Issued: 12/03/2013
• Est. Priority Date: 12/31/2009
• Status: Active Grant

• Current Assignee: Western Digital Technologies Incorporated (Western Digital Corporation)
• Original Assignee: HGST Netherlands B.V. (Western Digital Corporation)
• Inventors: Contreras, John, Knigge, Bernhard E.
• Primary Examiner(s): Agustin, Peter Vincent
• Application Number:
  US12/651,259
• Publication Number:
  US 20110157736A1
• Time in Patent Office: 1,433 Days
• Field of Search: None
• US Class Current: 360/31
• CPC Class Codes: G11B 5/6011 Control of flying height
• CPC Class Codes: G11B 5/6023 using inductive measurement
• CPC Class Codes: G11B 5/607 using thermal means
• CPC Class Codes: G11B 5/6076 Detecting head-disk contact

Abstract

A hard disk drive (HDD) including a slider. The slider includes a resistive temperature detector (RTD) configured to detect a temperature generated by one or more of slider spacing and contact with a media of said HDD. HDD also includes a slider signal controller configured to control bias signal of a slider with respect to a media potential, a real-time media-disk fly-height and contact detector configured to detect one or more of temperature generated by real-time media-disk slider spacing and real-time media-disk contact, and a real-time relative fly-height determiner configured to detect real-time relative fly-height of the slider based on analysis of a modulated portion of a high-frequency signal coupled to an element of the slider.

Claims

1. A hard disk drive (HDD) comprising:

a slider, wherein said slider comprises a resistive temperature detector (RTD) configured to detect a temperature generated by one or more of slider spacing and contact with a media of said HDD;

a slider signal controller configured to control bias signal of a slider with respect to a media potential;

a real-time media-disk fly-height and contact detector configured to detect one or more of temperature generated by real-time media-disk slider spacing and real-time media-disk contact; and

a real-time relative fly-height determiner configured to detect real-time relative fly-height of said slider based on analysis of a modulated portion of a high-frequency signal coupled to an element of said slider, wherein said slider signal controller, said real-time media-disk fly-height and contact detector, and said real-time relative fly-height determiner are included in a read/write Integrated Circuit (IC) of said HDD.

2. The HDD of claim 1, comprising:

a thermal fly-height control (TFC) element that is coupled to said RTD.

3. The HDD of claim 1, wherein a high-frequency signal coupled to an element of said slider comprises:

utilized read back data signal coupled from storage media to said a read transducer.

4. The HDD of claim 1, wherein a high-frequency signal coupled to an element of said slider comprises:

an auxiliary RF source coupled to an element of said slider selected from a group consisting of;

write element and read element.

5. The HDD of claim 1, comprising:

a modulation signal generator configured for generating a modulating signal that is injected into said slider to induce a sideband modulation of said high-frequency signal.

6. The HDD of claim 1, wherein said slider signal controller is further configured to control bias potential via direct current (DC) bias control.

7. The HDD of claim 1, wherein said slider signal controller is further configured to control bias potential via alternating (AC) bias control.

8. A read/write integrated circuit (IC) for a hard disk drive (HDD), wherein said read/write IC comprises:

a slider signal controller configured to control bias signal of a slider with respect to a media potential;

a real-time media-disk fly-height and contact detector configured to detect one or more of temperature generated by real-time media-disk slider spacing and real-time media-disk contact; and

a real-time relative fly-height determiner configured to detect real-time relative fly-height of said slider based on analysis of a modulated portion of a high-frequency signal coupled to an element of said slider.

9. The read/write IC of claim 8, wherein said high-frequency signal coupled to an element of said slider comprises:

an auxiliary RF signal capacitively coupled to a read transducer.

10. The read/write IC of claim 8, wherein said high-frequency signal coupled to an element of said slider comprises:

an auxiliary RF signal capacitively coupled to a write transducer.

11. The read/write IC of claim 8, comprising:

a modulation signal generator configured for generating a modulating signal that is injected into said slider to induce a sideband modulation of an auxiliary RF signal.

12. The read/write IC of claim 8, wherein said slider signal controller is further configured to control bias potential via direct current (DC) bias control.

13. The read/write IC of claim 8, wherein said slider signal controller is further configured to control bias potential via alternating (AC) bias control.

14. A method for integrating control of slider bias potential, touch-down detection and fly-height determination in a hard disk drive (HDD), said method comprising:

controlling slider bias potential with respect to a media potential;

detecting one or more of media-disk fly-height and contact in real-time based one or more of temperature generated by a real-time media-disk slider spacing and real-time media-disk contact; and

determining fly-height of said slider in real-time based on a high-frequency signal coupled to an element of a slider, wherein said controlling slider bias potential, said detecting one or more of media-disk fly-height and contact, and said determining fly-height of said slider occur substantially simultaneously, wherein determining fly-height comprises;

injecting a modulating signal into said slider to induce a sideband modulation of an auxiliary RF signal.

15. The method of claim 14, comprising:

coupling a thermal fly-height control (TFC) element to a resistive temperature detector (RTD).

16. The method of claim 14, wherein determining fly-height comprises:

analyzing of a modulated portion of an auxiliary Radio Frequency (RF) signal that is capacitively coupled to a portion of said slider.

17. The method of claim 16, comprising:

capacitively coupling said auxiliary RF signal to a read transducer.

18. The method of claim 16, comprising:

capacitively coupling said auxiliary RF signal to a write transducer.