Head including a heating element for reducing signal distortion in data storage systems

• US 6,069,853 A
• Filed: 01/08/1999
• Issued: 05/30/2000
• Est. Priority Date: 08/21/1998
• Status: Expired due to Fees

• Current Assignee: TeraStor Corporation
• Original Assignee: TeraStor Corporation
• Inventors: Bell, Jr., Bernard W., Novotny, Vlad, Diepersloot, David, Hajjar, Roger
• Primary Examiner(s): Dinh, Tan
• Application Number:
  US09/227,778
• Time in Patent Office: 508 Days
• Field of Search: 369/13, 369/14, 369/110, 369/116, 369/44.11, 369/44.14, 369/112, 369/120, 360/59, 360/114
• US Class Current: 369/13.33
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: G11B 11/10532 Heads
• CPC Class Codes: G11B 11/10554 the transducers being disposed on the same side of the carrier flying heads G11B11/1058
• CPC Class Codes: G11B 11/1058 Flying heads
• CPC Class Codes: G11B 2005/0002 Special dispositions or recording techniques
• CPC Class Codes: G11B 2005/0005 Arrangements, methods or circuits
• CPC Class Codes: G11B 2005/001 Controlling recording characteristics of record carriers or transducing characteristics of transducers by means not being part of their structure
• CPC Class Codes: G11B 2005/0013 of transducers, e.g. linearisation, equalisation
• CPC Class Codes: G11B 2005/0021 Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal
• CPC Class Codes: G11B 33/14 Reducing influence of physical parameters, e.g. temperature change, moisture, dust
• CPC Class Codes: G11B 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/41 Cleaning of heads of record carriers G11B23/50
• CPC Class Codes: G11B 7/12 Heads, e.g. forming of the optical beam spot or modulation of the optical beam disposition or mounting of head elements within housing or with provision for moving of light source, optical beam or detector, irrelevant to the transducing method G11B7/08 ; modulating lasers H01S3/10; controlling the intensity, colour, phase, polarisation or direction of light beams arriving from an independent light source, e.g. switching gating or modulating G02F1/00
• CPC Class Codes: G11B 7/127 Lasers; Multiple laser arrays lasers per se H01S
• CPC Class Codes: G11B 7/1356 Double or multiple prisms, i.e. having two or more prisms in cooperation
• CPC Class Codes: G11B 7/1362 Mirrors
• CPC Class Codes: G11B 7/1372 Lenses
• CPC Class Codes: G11B 7/1387 using the near-field effect
• CPC Class Codes: G11B 9/1409 Heads

Abstract

A device for retrieving data from or writing data to a storage medium that includes a heating element to reduce signal distortion in a data storage system. The device includes a head having an interfacing surface that faces a medium surface of the storage medium and interacts with the storage medium. The heating element is disposed on or near the interfacing surface to supply thermal energy to the interfacing surface maintain said interfacing surface at a temperature higher than a temperature of the medium surface.

Claims

1. A device for retrieving data from or writing data to a storage medium, comprising:

a head having an interfacing surface that faces a medium surface of the storage medium and interacts with the storage medium to retrieve data from or write data to the storage medium; and

a heating element disposed on or near said interfacing surface of said head and configured to supply thermal energy to said interfacing surface and to maintain said interfacing surface at a temperature higher than a temperature of the medium surface.

2. A device as in claim 1, wherein said head is configured to retrieve data from or write data to the storage medium by coupling radiation energy through said interfacing surface.

3. A device as in claim 2, further comprising a head positioning element and a medium holder to position said head and said storage medium relative to each other to allow radiation coupling at least in part by evanescent waves.

4. A device as in claim 2, wherein said head produces a numerical aperture that is greater than unity with respect to the storage medium for coupling the radiation energy.

5. A device as in claim 2, wherein said head includes an objective lens and a radiation-coupling element that couples the radiation energy to and from the storage medium.

6. A device as in claim 1, wherein said head includes a magnetic head and is configured to retrieve data from or write data to the storage medium by magnetic signals.

7. A device as in claim 1, wherein said heating element includes an electrical heater that consumes electrical energy to produce said thermal energy.

8. A device as in claim 7, wherein said electrical heater includes a conductor layer that is at least in part formed over said interfacing surface.

9. A device as in claim 7, wherein said electrical heater includes a conductor layer formed around said interfacing surface.

10. A device as in claim 7, wherein said electrical heater includes a coil.

11. A device as in claim 1, wherein said head includes a mesa having a flat mesa surface that constitutes said interfacing surface.

12. A device as in claim 11, wherein said heating element includes a conductor layer formed over at least one of surfaces of said mesa.

13. A device as in claim 1, wherein said heating element includes a radiation-absorbing layer formed over said interfacing surface and configured to produce said thermal energy by receiving and absorbing a selected radiation.

14. A device as in claim 1, wherein said interfacing surface is maintained at a temperature higher than a desorption temperature below which certain species become adsorbed to said interfacing surface.

15. A device for retrieving data from or writing data to a storage medium through a medium surface on which certain adsorbed species become desorbed to escape from the medium surface when the temperature of the medium surface is higher than a desorption temperature, comprising:

a head having an interfacing surface that faces a medium surface of the storage medium and interacts with the storage medium through the medium surface; and

a heating element disposed in thermal coupling with said interfacing surface of said head and configured to supply thermal energy to said interfacing surface so that said interfacing surface has a temperature higher than the desorption temperature.

16. A device as in claim 15, wherein said head is configured to retrieve data from or write data to the storage medium by coupling radiation energy through said interfacing surface and the medium surface.

17. A device as in claim 16, wherein said head couples radiation energy to and from the storage medium at least in part by evanescent waves.

18. A device as in claim 16, wherein said head couples radiation energy to and from the storage medium by wave propagation and said head produces a numerical aperture that is less than unity with respect to the storage medium.

19. A device as in claim 15, wherein said head includes a magnetic head and is configured to retrieve data from or write data to the storage medium by magnetic signals.

20. A device as in claim 15, wherein said heating element includes an electrical heater that consumes electrical energy to produce said thermal energy.

21. A device as in claim 20, wherein said electrical heater includes a conductor layer that is at least in part formed over said interfacing surface.

22. A device as in claim 20, wherein said electrical heater includes a conductor layer formed around said interfacing surface.

23. A device as in claim 20, wherein said electrical heater includes a coil.

24. A device as in claim 15, wherein said head includes a mesa having a flat mesa surface that constitutes said interfacing surface.

25. A device as in claim 24, wherein said heating element includes a conductor layer formed over at least one of surfaces of said mesa.

26. A device as in claim 15, wherein said heating element includes a radiation-absorbing layer formed over said interfacing surface and configured to produce said thermal energy by receiving and absorbing a selected radiation.

27. A device as in claim 15, wherein said interfacing surface is maintained at a temperature higher than the local temperature of the medium surface exposed to the light beam.

28. An optical storage device for using optical radiation to write data to or retrieve data from an optical storage medium, comprising:

an optical head having an optical surface that couples radiation energy to and from a medium surface of the optical storage medium;

a medium holder adopted to hold the optical storage medium, and positioned relative to said optical head to allow coupling of the radiation energy between said optical surface of said optical head and the medium surface of the optical storage medium; and

a heating element, thermally coupled to said optical surface of said optical head, and configured to supply thermal energy to maintain said optical surface above a selected temperature below which certain species become adsorbed to said optical surface.

29. A device as in claim 28, wherein said optical surface is maintained at a temperature higher than the temperature of the medium surface.

30. A device as in claim 28, wherein said medium holder is so positioned that said optical surface is spaced from the medium surface by a distance less than one wavelength of the radiation energy.

31. A device as in claim 28, wherein said optical head includes an objective lens and a solid immersion lens which has a spherical surface and a flat surface, said flat surface opposing said spherical surface and coupling the radiation energy to and from the optical storage medium.

32. A device as in claim 28, wherein said optical head includes a solid immersion mirror for coupling the radiation energy to and from the optical storage medium.

33. A device as in claim 28, wherein said optical head includes a diffractive optical element for coupling the radiation energy to and from the optical storage medium.

34. A device as in claim 28, wherein said optical head includes a radially graded index rod lens for coupling the radiation energy to and from the optical storage medium.

35. A device as in claim 28, wherein said heating element includes an electrical heater that consumes electrical energy to produce said thermal energy.

36. A device as in claim 35, wherein said electrical heater includes a conductor layer that is at least in part formed over said optical surface.

37. A device as in claim 35, wherein said electrical heater includes a conductor layer formed around said optical surface to expose at least a portion of said optical surface for transmitting the radiation energy.

38. A device as in claim 35, wherein said electrical heater includes a coil.

39. A device as in claim 28, wherein said optical head includes a mesa having a flat mesa surface that constitutes said optical surface.

40. A device as in claim 39, wherein said heating element includes a conductor layer formed over at least one of surfaces of said mesa.

41. A device as in claim 39, wherein said heating element includes a coil formed around said mesa.

42. A device as in claim 28, wherein said heating element includes a radiation-absorbing layer formed over said optical surface and configured to produce said thermal energy by receiving and absorbing the radiation energy for writing data to or retrieving data from the optical storage medium.

43. A device as in claim 42, wherein said radiation-absorbing layer is configured to have a one-pass absorption at or less than about 5%.

44. A device as in claim 42, wherein said radiation-absorbing layer includes an amorphous hydrogenated or nitrogenated carbon material.

45. A device as in claim 42, wherein said radiation-absorbing layer includes indium-tin oxide, tin oxide, or indium oxide.

46. A device as in claim 42, wherein said radiation-absorbing layer has a hardness of greater than about 16 GPA.

47. A device as in claim 28, further comprising:

a radiation source positioned relative to said optical head to provide a heating radiation beam at a heating wavelength different from the wavelength of the radiation energy for writing data to or retrieving data from the optical storage medium,

wherein said heating element includes a radiation-absorbing layer formed over said optical surface and configured to be substantially transparent to the radiation energy for writing data to or retrieving data from the optical storage medium and to absorb said heating radiation beam to produce said thermal energy.

48. A device as in claim 47, wherein said radiation-absorbing layer has a hardness of greater than about 16 GPA.

49. A device as in claim 47, further comprising a dichroic beam splitter positioned between said optical head and said radiation source to direct said heating radiation beam to said optical head.

50. A device as in claim 47, further comprising an optical fiber element positioned to guide said heating radiation beam from said radiation source to said optical head.

51. A device as in claim 28, wherein said medium holder is so configured that the optical storage medium is removable and is replaced by another removable optical storage medium.

52. A device as in claim 28, wherein said medium holder is so configured that the optical storage medium is affixed to said medium holder.

53. A device as in claim 28, wherein the optical storage medium includes a thermal insulating layer that reduces transfer of heat generated by absorption of the radiation energy by the medium to the medium surface.

54. A method for configuring and operating a data storage system that comprises a head to read data from or to write data to a storage medium by accessing the storage medium through a medium surface, comprising:

energizing the head to interact with the storage medium via an interfacing surface in the head to read data from or to write data to the storage medium; and

heating the head to raise a temperature of the interfacing surface higher than a desorption temperature below which certain species become adsorbed to the interfacing surface.

55. A method as in claim 54, wherein the head is energized by an optical beam.

56. A method as in claim 55, further comprising:

placing the head with respect to the storage medium in a near-field configuration in which the interfacing surface of the head is separated from the medium surface of the storage medium by less than one wavelength of the optical beam.

57. A method as in claim 54, wherein the head is energized by a magnetic unit capable of producing a magnetic field and sensing magnetic signals.

58. A method as in claim 54, wherein the interfacing surface is heated by an electrical heater attached to the head.

59. A method as in claim 54, wherein the interfacing surface is heated by thermal energy generated from absorption of an optical beam.

60. A method as in claim 54, wherein the temperature of interfacing surface is higher than the temperature of the medium surface.

61. A method as in claim 54, wherein the head is heated by a bulk heater that are disposed to raise the temperature of at least a portion of the head adjacent to the interfacing surface.

62. A method as in claim 54, wherein the head is heated by a layer of heat-generating element formed on or near the interfacing surface of the head.

63. A method as in claim 54, further comprising:

removing adsorbed species from the interfacing surface by contacting the interfacing surface with another surface or the storage medium in a controlled manner.