Optical pickup using an optical phase plate
AssigneeSamsung Electronic Co., Ltd.
InventorsJang Hoon Yoo, Chul Woo Lee, Chong Sam Chung, Pyong Yong Seong, Kun Ho Cho, Hyun Seob Choi, Yong Hoon Lee, Tae Kyung Kim, No Kyong Park
Life of this patent
Estimating the term…
Abstract
A recording/reproducing apparatus includes an optical pickup device having an optical phase plate which is compatible with optical recording mediums having different thicknesses, and an optical signal processing device processes information read from the optical recording mediums and processes information to be recorded thereon using the optical pickup device.
Claims34
A recording and/or reproducing apparatus compatible with optical recording media having different thicknesses, comprising:
- a plurality of laser light sources for emitting a first light beam and a second light beam having different wavelengths, respectively;
- an objective lens having a predetermined focal length, in which a focal point of said objective lens according to the first light beam coincides with a position on the information recording surface in a first optical recording medium;
- optical detection means;
- optical path control means for controlling an optical path so that at least one of the first and second light beams emitted from one of the laser light sources is directed to said objective lens and light output from said objective lens is directed to said optical detection means;
- phase shifting means, located between said optical path control means and said objective lens, for shifting a phase of a portion of the second light beam proceeding from said optical path control means to said objective lens, thereby reducing a size of a beam spot which is formed on a position of the information recording surface in the second optical recording medium by the second light beam focussed with said objective lens;
- and
- a processing unit which processes an information signal to control the light beams generated by said laser light sources, and for processing a detected light from said optical detection means,
- wherein a wavelength of one of the first and second light beams is chosen according to the optical recording media to be used.
A recording and/or reproducing apparatus for at least two optical recording media, which are different in distance from an optical pickup to an information recording surface and using light beams having different wavelengths for recording and reading information, the recording and/or reproducing apparatus comprising:
- a plurality of laser light sources for emitting a first light beam and a second light beam having different wavelengths, respectively;
- an objective lens having a predetermined focal length, in which a focal point of said objective lens according to the first light beam coincides with a position on the information recording surface in a first optical recording medium,
- wherein said objective lens includes a groove having a predetermined width and depth for shifting a phase of a portion of the second light beam, thereby reducing a size of a beam spot which is formed on a position of the information recording surface in a second optical recording medium;
- means for optical detection;
- means for controlling an optical path so that at least one of the first and second light beams emitted from one of the laser light sources is directed to said objective lens and light output from said objective lens is directed to said optical detection means;
- and
- processing means for processing an information signal to control the light beams generated by said laser light sources, and for processing a detected light from said optical detection means,
- wherein a wavelength of one of the first and second light beams is chosen according to the optical recording media to be used.
A recording and/or reproducing apparatus for at least two optical recording media, which are different in distance from an optical pickup to an information recording surface and using light beams having different wavelengths for recording and reading information, the recording and/or reproducing apparatus comprising:
- a plurality of laser light sources for emitting a first light beam and a second light beam having different wavelengths, respectively;
- an objective lens having a predetermined focal length, in which a focal point of said objective lens according to the first light beam coincides with a position on the information recording surface in a first optical recording medium;
- an optical detector for detecting light;
- a variable aperture which controls an optical path so that at least one of the first and second light beams emitted from one of the laser light sources is directed to said objective lens and light output from said objective lens is directed to said optical detector and detected by said optical detector,
- wherein said objective lens includes a groove having a predetermined width and depth, which is concaved from a surface of said objective lens disposed relatively closer to said variable aperture, said groove for shifting a phase of a portion of the second light beam proceeding from said variable aperture to said objective lens, thereby reducing a size of a beam spot which is formed on a position of the information recording surface in a second optical recording medium by the second light beam focussed with said objective lens;
- and
- a processing unit which processes an information signal to control the light beams generated by said laser light sources, and for processing a detected light from said optical detector;
- wherein a wavelength of one of the first and second light beams is chosen according to the optical recording media to be used.
A recording and/or reproducing apparatus for at least two optical recording media, which are different in distance from an optical pickup to an information recording surface and using light beams having different wavelengths for recording and reading information, the recording and/or reproducing apparatus comprising:
- a plurality of laser light sources for emitting a first light beam and a second light beam which have different wavelengths, respectively;
- an objective lens divided into an inner region, a phase shift region and an outer region centering on an optical axis, wherein a light beam passing through the inner region always forms a beam spot on the information recording surface in an optical recording medium regardless of the kind of the information recording medium, and the phase shift region shifts a phase to reduce a spherical aberration with respect to at least one light beam to be incident, thereby forming the beam spot on the information recording surface in the optical recording medium;
- means for optical detection;
- means for controlling an optical path so that at least one of the first and second light beams emitted from one of the laser light sources is directed to said objective lens and light output from said objective lens is directed to said optical detection means, and
- processing means for processing an information signal to control the light beams generated by said laser light sources, and for processing a detected light from said optical detection means,
- wherein the wavelength of one of the first and second light beams is chosen according to the optical recording medium to be used.
A recording and/or reproducing apparatus for at least two recording media, which are different in distance from an optical pickup to an information recording surface and using light beams for recording and reading information, the recording and/or reproducing apparatus comprising:
- a light source to emit a light beam;
- an objective lens divided into an inner region, a phase shift region and an outer region, wherein said light beam passing through the inner region always forms a beam spot on the information recording surface in an optical recording medium regardless of the kind of information recording medium, and the phase shift region shifts a phase of said light beam for forming the beam spot on the information recording surface for a particular type of optical recording medium;
- optical detection means for detecting light reflected from at least one of the two recording media;
- a beam splitter for transmitting/reflecting light from said light source toward said objective lens and for reflecting/transmitting light reflected from the at least one of the two recording media toward said optical detection means;
- and
- a processing unit which processes an information signal to control the light beam generated by said laser light source, and for processing a detected light from said optical detection means.
A recording and/or reproducing apparatus for at least two recording media, which are different in distance from an optical pickup to an information recording surface and using light beams for recording and reading information, the recording and/or reproducing apparatus comprising:
- a light source to emit a light beam;
- a phase shifter which receives said light beam to shift the phase of said light beam;
- an objective lens which receives said light beam transmitted by said phase shifter to focus said light beam on the two recording media having a different thickness;
- optical detection means for detecting light reflected from at least one of the two recording media;
- a beam splitter for transmitting/reflecting light from said light source toward said objective lens and for reflecting/transmitting light reflected from the at least one of the two recording media toward said optical detection means;
- and
- a processing unit which processes an information signal to control the light beam generated by said laser light source, and for processing a detected light from said optical detection means.
Dependencies are inferred from the claim text.