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US 6,611,488 B1Granted
Optical head, optical part, and optical memory apparatus having controlled optical intensity
AssigneeFujitsu Limited
InventorsWataru Odajima, Shinya Hasegawa
Life of this patent
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Abstract
An optical part has an exit surface from which beams of light applied through an incident surface are emitted, and a transmission film permitting the beams of light emitted from the exit surface to be transmitted at higher transmittance with higher light intensity. The exit surface is covered by the transmission film.
Claims24
An optical head applying beams of light to a surface of the storage medium, said optical head comprising:
- a light emission unit for emitting a light beam;
- an optical part having an incident surface onto which the light beam is incident and an exit surface from which the light beam applied through the incident surface is emitted;
- and
- a transmission unit permitting part of a predetermined optical intensity or more of the light beam emitted from the exit surface of said optical part to pass through said transmission unit, wherein said transmission unit is made of a material in which part of an incident light energy is converted into a thermal energy, said material permitting an incident light to be transmitted at a higher transmittance with a higher temperature.
1 more element
An optical head applying beams of light to a surface of the storage medium, said optical head comprising:
- a light emission unit for emitting a light beam;
- an optical part having an incident surface onto which the light beam is incident and an exit surface from which the light beam applied through the incident surface is emitted;
- and
- a transmission unit permitting part of a predetermined optical intensity or more of the light beam emitted from the exit surface of said optical part to pass through said transmission unit, wherein said transmission unit is made of a saturable absorber having properties in which an absorbency index is lowered in accordance with an increment of an incident light intensity.
1 more element
An optical part comprising:
- an incident surface onto which a light beam is incident;
- an exit surface from which the light beam applied through said incident surface is emitted;
- and
- a transmission unit permitting part of the light beam emitted from the exit surface to be transmitted at higher transmittance with higher light intensity, wherein said transmission unit is made of a material in which part of an incident light energy is converted into a thermal energy, said material permitting an incident light to be transmitted at a higher transmittance with a higher temperature.
1 more element
An optical part comprising an incident surface onto which a light beam is incident, and an exit surface from which the light beam applied through said incident surface is emitted;
- and
- a transmission unit permitting part of a predetermined optical intensity or more of the light beam emitted from the exit surface of said optical part to pass through said transmission unit, wherein said transmission unit is made of a saturable absorber having properties in which absorbency index is lowered in accordance with an increment of an incident light intensity.
An optical memory apparatus comprising:
- a light emission unit for emitting a light beam;
- an optical part having at least a transmission unit permitting part of a predetermined optical intensity or more of the light beam emitted from the light emission unit to pass through said transmission unit, wherein said transmission unit is made of a material in which part of an incident light energy is converted into a thermal energy, said material permitting an incident light to be transmitted at a higher transmittance with a higher temperature;
- a storage medium holding mechanism for holding a storage medium, to which the part of the light beam is applied, at a predetermined position;
- and
- an optical part driving mechanism for driving said optical part.
2 more elements
An optical memory apparatus comprising:
- a light emission unit for emitting a light beam;
- an optical part having at least a transmission unit permitting part of a predetermined optical intensity or more of the light beam emitted from the light emission unit to pass through said transmission unit, wherein said transmission unit is made of a saturable absorber having properties in which an absorbency index is lowered in accordance with an increment of an incident light intensity;
- a storage medium holding mechanism for holding a storage medium, to which the part of the light beam is applied, at a predetermined position;
- and
- an optical part driving mechanism for driving said optical part.
2 more elements
An optical memory apparatus comprising:
- a light emission unit for emitting a light beam;
- an optical part having an incident surface onto which the light beam is incident, and an exit surface from which the light beam applied through the incident surface is emitted, said optical part being formed so as to condense the light beam on the exit surface and having a numerical aperture not more than 0.75;
- a storage medium holding mechanism for holding a storage medium, to which the light beam is applied, at a predetermined position;
- and
- an optical part driving mechanism for driving said optical part in a state that the storage medium held by said storage medium holding mechanism and said exit surface are spaced from one another by a length not more than one-tenth of a wavelength of the light beam.
2 more elements
Dependencies are inferred from the claim text.