Apparatus for optical pick-up
AssigneeLG Electronics Inc.
InventorBoo Bin Yim
Life of this patent
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Abstract
An optical pickup includes a light source configured to emit light, a beam splitter configured to transmit or reflect light, an object lens configured to condense the light transmitted by the beam splitter onto an optical storage, and a diffraction grating having a first grating pattern and a second grating pattern. The first grating pattern is configured to diffract and divide the light reflected by the optical storage into a main beam and two sub beams. The second grating pattern is configured to diffract the light along a different diffracting direction than the first grating pattern. A condensing lens is configured to generate astigmatism to the light diffracted by the first grating pattern, and a light sensor is configured to receive the light via the condensing lens and detect a tracking error signal.
Claims2
An optical pickup comprising:
- a light source configured to emit light;
- a beam splitter configured to transmit or reflect light;
- an object lens configured to condense the light transmitted by the beam splitter onto an optical storage;
- a diffraction grating having a first grating pattern and a second grating pattern, the first grating pattern configured to diffract and divide said light reflected by the optical storage into a main beam and two sub beams, and the second grating pattern configured to diffract said light along a different diffracting direction than the first grating pattern so that the diffracted light by the second grating pattern is excluded from an error detecting process;
- a condensing lens configured to generate astigmatism to the light diffracted by the first grating pattern;
- and
- a light sensor configured to receive the light via the condensing lens and detect a tracking error signal;
- wherein
- the first grating pattern has an hour glass shape and is disposed in a central portion of the diffraction grating;
- and
- the second grating pattern covers a remainder of the diffraction grating.
An optical pickup comprising:
- a light source configured to emit light;
- a beam splitter configured to transmit or reflect light;
- an object lens configured to condense the light transmitted by the beam splitter onto an optical storage;
- a diffraction grating having a first grating pattern and a second grating pattern,
- the first grating pattern configured to diffract and divide said light reflected by the optical storage and then reflected by the beam splitter into a main beam and two sub beams, and the second grating pattern configured to diffract said light along a different diffracting direction than the first grating pattern so that the diffracted light by the second grating pattern is excluded from an error detecting process;
- a condensing lens configured to generate astigmatism to the light diffracted by the first grating pattern;
- and
- a light sensor configured to receive the light via the condensing lens and detect a tracking error signal;
- wherein
- the first grating pattern has an hour glass shape and is disposed in a central portion of the diffraction grating;
- and
- the second grating pattern covers a remainder of the diffraction grating.
Dependencies are inferred from the claim text.