Method for controlling writing in a thermally-assisted recording (TAR) disk drive with thermal fly-height control

摘要

A thermally-assisted recording (TAR) disk drive operates by turning on write current prior to the application of heat to the recording layer by the near-field transducer (NFT). In a TAR disk drive that uses thermal fly-height control (TFC), TFC power is at a first power level that keeps the write pole at a predetermined fly-height. The write current is then turned on, either simultaneously with or after a reduction in TFC power. The write pole then reaches its optimal fly-height as a result of the combination of write pole protrusion caused by the write current and retraction of the write pole caused by the reduction in TFC power. After the write pole has reached its optimal fly-height, heat is applied to the recording layer by the NFT. The combination of write current and heat causes writing to occur at the optimal write pole fly-height.

主权项

1. A method for writing to a magnetic recording layer in a thermally-assisted recording (TAR) disk drive, the disk drive including a disk having a magnetic recording layer, a laser diode, and an air-bearing slider having an air-bearing surface (ABS) facing the disk, wherein the slider supports a write coil, a write pole coupled to the write coil and having a tip at the ABS, and a near-field transducer (NFT) at the ABS and coupled to the laser diode, the method comprising:
prior to writing, applying write current to the write coil to generate a magnetic field from the write pole, the write current causing protrusion of the write pole toward the recording layer; after the write pole has reached its maximum protrusion, applying power to the laser diode to heat the recording layer; and writing to the recording layer using the pre-existing magnetic field from the write pole; and wherein the time for the write pole to reach its maximum protrusion after application of write current to the coil is Δt, and wherein power to the laser diode is applied at a time greater than Δt after application of write current to the coil.