Photoconductive optical write driver for magnetic recording
View Patent ↗A write driver for use with a magnetic recording head includes a photoconductive switch that is positioned adjacent a magnetic recording head for switching current waveforms. Both light and a DC voltage are applied to the photoconductive switch to switch the applied current waveforms. The write driver further includes means for writing to a storage medium in response to current waveforms switched by the photoconductive switch. The write driver may also include a suspension that supports at least one photoconductive switch, DC conductors for supplying a DC voltage, means for supplying light, and recording head means for writing to a storage medium.
1. A write driver for magnetic recording, comprising:
at least one photoconductive switch positioned adjacent a magnetic recording head for generating current waveforms;
DC conductors for supplying a DC voltage to said photoconductive switch;
means for supplying light to said photoconductive switch; and
recording head means for writing to a storage medium in response to current waveforms generated by said photoconductive switch.
2. The write driver of claim 1 , wherein said photoconductive switch comprises a semiconducting substrate comprising a material selected from the group of silicon, silicon-on-sapphire (SOS), low-temperature-grown GaAs, semi-insulating GaAs, SiGe, and SiO 2 /Si 3 N 4 .
3. The write driver of claim 1 , wherein said photoconductive switch switches said DC voltage to produce a fast risetime write current when said switch is optically illuminated.
4. The write driver of claim 1 , wherein said photoconductive switch comprises a metal-semiconductor-metal configuration.
5. The write driver of claim 1 , wherein said DC conductors comprise at least one positive electrode, at least one negative electrode and a ground.
6. The write driver of claim 5 , wherein said DC conductors comprise a single voltage electrode and a ground on a suspension.
7. The write driver of claim 1 , wherein said photoconductive switch comprises a gap between at least two DC conductors.
8. The write driver of claim 1 , wherein said means for supplying light comprise a laser.
9. The write driver of claim 1 , wherein said means of supplying light includes at least one optical fiber for directing light from a light source to said photoconductive switch.
10. The write driver of claim 1 , wherein said means of supplying light includes at least one mirror or lens for directing light from a light source to said photoconductive switch.
11. The write driver of claim 1 , wherein said recording head means are structured and arranged for perpendicular recording to said storage medium.
12. The write driver of claim 1 , wherein said recording head means are structured and arranged for longitudinal recording to said storage medium.
13. The write driver of claim 1 , wherein said recording head means includes a read device.
14. The write driver of claim 1 , wherein said means for writing to a storage medium comprise a recording head having at least one recording head conductor structured and arranged to receive current waveforms from said photoconductive switch and to communicate said current waveforms to a write pole structured and arranged for magnetic recording.
15. The write driver of claim 1 , wherein said means for writing to a storage medium comprises a pair of write poles with a connecting yoke therebetween, said pair of write poles structured and arranged to apply a magnetic write field to a magnetic storage medium.
16. The write driver of claim 1 , wherein said means for writing to a storage medium comprises a pair of write poles having a connecting yoke therebetween, structured and arranged to apply a magnetic write field to a magnetic storage medium, having two coils of opposite polarity wound around said yoke.
17. The write driver of claim 1 , further comprising a slider positioned adjacent said recording head means for positioning said recording head in magnetic communication with said storage medium.
18. The write driver of claim 1 , further comprising a suspension, said suspension supporting at least one of said at least one photoconductive switch, said DC conductors for supplying a DC voltage, said means for supplying light, and said recording head means for writing to a storage medium.
19. The write driver of claim 1 , further comprising an interconnect for carrying current from said photoconductive switch to said recording head means.
20. The write driver of claim 19 , wherein said interconnect is from about 0.1 to about 2 mm in length.
21. The photoconductive optical write driver of claim 1 , further comprising a transmission line positioned between said DC conductors having an applied DC voltage and said photoconductive switch, said recording head means for writing to a storage medium including means for discharging a charged section of said transmission line through said photoconductive switch.
22. The write driver of claim 21 , wherein said transmission line comprises a coaxial cable.
23. The write driver of claim 1 , further comprising a preamp for pulsed field writing.
24. A recording device for use with magnetic storage media, comprising:
a write driver, comprising:
at least one photoconductive switch positioned adjacent a magnetic recording head for generating current waveforms;
DC conductors for supplying a DC voltage to said photoconductive switch;
means for supplying light to said photoconductive switch; and
means for writing to a storage medium in response to current waveforms generated by said photoconductive switch.
25. The recording head of claim 24 wherein, said means for supplying light comprise a laser.
26. The recording head of claim 24 wherein, said means for supplying light includes at least one optical fiber for directing light from a light source to said photoconductive switch.
27. The recording head of claim 24 wherein, said means for writing to a storage medium comprise a write pole structured and arranged for perpendicular or longitudinal recording to said storage medium.
28. The recording head of claim 24 wherein, said means for writing to a storage medium comprise a pair of write poles with a connecting yoke therebetween, structured and arranged to apply a magnetic write field to said storage medium.
29. The recording head of claim 24 wherein, said means for writing to a storage medium comprise a pair of write poles having a connecting yoke therebetween, structured and arranged to apply a magnetic write field to said storage medium, and having two coils of opposite polarity wound around said yoke.
30. A magnetic disc drive storage system, comprising:
a housing;
a rotatable magnetic storage medium positioned in said housing, said magnetic storage medium having a plurality of magnetic tracks, each of the tracks having a plurality of magnetic domains; and
a movable device mounted in said housing adjacent said magnetic storage medium,
said device including a photoconductive optical write driver for magnetic recording, said photoconductive optical write driver comprising:
at least one photoconductive switch positioned adjacent a magnetic device for generating current waveforms;
DC conductors for supplying a DC voltage to said photoconductive switch;
means for supplying light to said photoconductive switch; and
means for writing to a storage medium in response to current waveforms generated by said photoconductive switch.
31. The recording head of claim 30 wherein, said means for supplying light comprise a laser.
32. The recording head of claim 30 wherein, said means for supplying light includes at least one optical fiber for directing light from a light source to said photoconductive switch.
33. The recording head of claim 30 wherein, said means for writing to a storage medium comprise a write pole structured and arranged for perpendicular or longitudinal recording to said storage medium.
34. The recording head of claim 30 wherein, said means for writing to a storage medium comprise a pair of write poles with a connecting yoke therebetween, structured and arranged to apply a magnetic write field to said storage medium.
35. The recording head of claim 30 wherein, said means for writing to a storage medium comprise a pair of write poles having a connecting yoke therebetween, structured and arranged to apply a magnetic write field to said storage medium, and having two coils of opposite polarity wound around said yoke.