Optical pickup unit, apparatus for recording/reproducing data, method for controlling the apparatus, control method, and recording medium
AssigneeLG Electronics Inc.
InventorsJeong Kyo Seo, In Ho Choi, Byung Hoon Min
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Abstract
An optical pickup unit, an apparatus for recording/reproducing data, a control method, and a recording medium are disclosed. Each of the optical pickup unit and the recording/reproducing apparatus includes a near-field lens, and uses a high-refraction lens, conically shaped, to effectively use the near-field. Two lens units are required to be compatible with a conventional recording medium. The lens unit is designed in consideration of a distance between the recording medium and the lens, and the tilt or vibration of the lens units is controlled.
Claims18
An optical pickup apparatus comprising;
- a first lens unit including a first objective lens and a high-refraction lens;
- a second lens unit including a second objective lens;
- and
- at least one separating/combining unit for separating or combining paths of an optical signal passing through the first or second lens unit,
- wherein there is a height difference between the first lens unit and the second lens unit,
- wherein the height difference is decided in consideration of a physical tilt limitation angle or a vibration range during a recording/reproducing operation,
- wherein the physical tilt limitation angle is calculated by the following equation,
- α
- =
- tan
- -
- 1
- (
- d
- r
- )
- ,
- wherein a bottom radius at a lower part of the high-refraction lens is r and an interval between the high-refraction lens and a recording medium is d,
- wherein the vibration range is limited to maximum of 0.1 mm.
An apparatus for recording/reproducing data comprising:
- a first lens unit including a first objective lens and a high-refraction lens;
- a second lens unit including a second objective lens;
- at least one separating/combining unit for separating or combining paths of an optical signal passing through the first or second lens unit;
- a signal generator for generating a control signal corresponding to an interval between the first lens unit and a recording medium using an optical signal received from the first lens unit;
- and
- a control part configured to control the interval between the first lens unit and the recording medium within a predetermined range using the control signal,
- wherein there is a height difference between the first lens unit and the second lens unit,
- wherein the height difference is decided in consideration of a physical tilt limitation angle or a vibration range during a recording/reproducing operation,
- wherein the physical tilt limitation angle is calculated by the following equation,
- α
- =
- tan
- -
- 1
- (
- d
- r
- )
- ,
- wherein a bottom radius at a lower part of the high-refraction lens is r and an interval between the high-refraction lens and a recording medium is d,
- wherein the vibration range is limited to maximum of 0.1 mm.
Dependencies are inferred from the claim text.