초록 ▼

A thermally-assisted magnetic recording head and a magnetic recording apparatus having the magnetic recording head built in are disclosed. The magnetic recording head is capable of recording magnetic information by heating a recording unit of a recording medium and raising its temperature to reduce

A thermally-assisted magnetic recording head and a magnetic recording apparatus having the magnetic recording head built in are disclosed. The magnetic recording head is capable of recording magnetic information by heating a recording unit of a recording medium and raising its temperature to reduce magnetic coercive force and then applying recording magnetic field to the recording unit having the reduced coercive force. The magnetic recording head has a light absorbing film having an aperture, a laser device emitting and directing light through the aperture to the recording medium to head the recording unit and raise its temperature, and a recording magnetic pole for applying the recording magnetic field to the recording unit. In the aperture, an aperture width W1 is along a polarizing direction of the light emitted from the laser device while an aperture width W2 is approximately perpendicular to the polarizing direction of the aperture width W1, and the aperture width W1 is shorter than the aperture width W2. The heating source such as a laser device recedes from the medium to provide a unique configuration where a tip of the recording magnetic pole protrudes ahead of the heating source, and hence, heating beam and the recording magnetic pole can be located close to each other without losing sufficient energy density to heat the medium.

대표청구항 ▼

What is claimed is: 1. A thermally-assisted magnetic recording head capable of recording information magnetically on a recording medium, comprising: a laser device configured to emit a light to heat the recording medium to reduce a magnetic coercive force thereof; a light absorbing film provided be

What is claimed is: 1. A thermally-assisted magnetic recording head capable of recording information magnetically on a recording medium, comprising: a laser device configured to emit a light to heat the recording medium to reduce a magnetic coercive force thereof; a light absorbing film provided between the laser device and the recording medium, the light absorbing film having an aperture through which the light is applied to the recording medium; a magnetic pole configured to record the information magnetically on the recording medium by applying a recording magnetic field to the recording medium having the reduced coercive force; and an optical light collecting unit configured to asymmetrically converge the light emitted from a light emitting face of the laser device and to direct the converged light into the aperture, the aperture being adapted so that a polarizing direction of the light emitted from the laser device is approximately perpendicular to a direction along a longitudinal extension of recording tracks formed on the recording medium, a width W1 of the aperture taken along the polarizing direction being smaller than a width W2 of the aperture taken approximately perpendicular to the polarizing direction, the width W1 being shorter than 쩍 of a wavelength at the center of a spectrum of the light emitted from the laser device, and the optical light collecting unit shifting a peak of a distribution of a light intensity of the converged light from a first position to a second position due to the asymmetrical convergence, the second position being closer to the magnetic pole than the first position. 2. The thermally-assisted magnetic recording head according to claim 1, further comprising a dielectric film provided between the laser device and the light absorbing film. 3. The thermally-assisted magnetic recording head according to claim 2, wherein an optical film thickness of the dielectric film is in a range from 0.05λ to 0.35λ relative to the wavelength λ of the light emitted from the laser device. 4. The thermally-assisted magnetic recording head according to claim 1, wherein the width W1 is within a range in which an absorption loss through the aperture of light having an electric field vector perpendicular to the direction of the aperture width W1 is 10 times as much as an absorption loss through the aperture of light having a magnetic field vector perpendicular to the direction of the aperture width W1, or even higher. 5. The thermally-assisted magnetic recording head according to claim 1, wherein the laser device is a semiconductor laser device of which laser oscillation mode is a TM mode. 6. The thermally-assisted magnetic recording head according to claim 1, further comprising an optical light collector which converges the light emitted from the laser device to direct it into the aperture. 7. The thermally-assisted magnetic recording head according to claim 1, wherein the aperture is filled with dielectric or semiconductor material. 8. The thermally-assisted magnetic recording head according to claim 1, wherein the aperture has a rectangular shape. 9. The thermally-assisted magnetic recording head according to claim 1, wherein the light absorbing film has a flattened surface. 10. The thermally-assisted magnetic recording head according to claim 1, wherein the optical light collecting unit is a diffraction grating lens having an eccentric deployment. 11. The thermally-assisted magnetic recording head according to claim 1, wherein the optical light collecting unit has an asymmetrical distribution of a refractive index. 12. A thermally-assisted magnetic recording apparatus capable of recording information magnetically on a recording medium, comprising: a thermally-assisted magnetic recording head; and an actuating mechanism configured to move the recording medium and the magnetic recording head relative to each other, wherein the thermally-assisted magnetic recording head includes: a laser device configured to emit a light to heat the recording medium to reduce a magnetic coercive force thereof; a light absorbing film provided between the laser device and the recording medium, the light absorbing film having an aperture through which the light is applied to the recording medium; a magnetic pole configured to record the information magnetically on the recording medium by applying a recording magnetic field to the recording medium having the reduced coercive force; and an optical light collecting unit configured to asymmetrically converge the light emitted from a light emitting face of the laser device and to direct the converged light into the aperture, the aperture being adapted so that a polarizing direction of the light emitted from the laser device is approximately perpendicular to a direction along a longitudinal extension of recording tracks formed on the recording medium, a width of the aperture taken along the polarizing direction being smaller than a width of the aperture taken approximately perpendicular to the polarizing direction, and the width W1 being shorter than 쩍 of a wavelength at the center of a spectrum of the light emitted from the laser device, and the optical light collecting unit shifting a peak of a distribution of a light intensity of the converged light from a first position to a second position due to the asymmetrical convergence, the second position being closer to the magnetic pole than the first position. 13. The thermally-assisted magnetic recording apparatus according to claim 12, further comprising a recording medium, the recording medium including a record layer in which magnetic information is recorded, and an antireflection layer made of dielectric or semiconductor material deposited over the record layer. 14. The thermally-assisted magnetic recording apparatus according to claim 12, wherein the light absorbing film has a flattened surface. 15. The thermally-assisted magnetic recording apparatus according to claim 12, wherein the optical light collecting unit is a diffraction grating lens having an eccentric deployment. 16. The thermally-assisted magnetic recording apparatus according to claim 12, wherein the optical light collecting unit has an asymmetrical distribution of a refractive index.