摘要:
Provided are an optical pickup device, an objective optical element, and an optical information recording/reproducing device capable of recording and/or reproducing information to/from optical discs of different types in a compatible manner. The optical pickup device includes a first light source for emitting a first light flux, a second light source for emitting a second light flux, a third light source for emitting a third light flux, and an objective optical element. The objective optical element has an optical surface having at least two areas, i.e., a central area and a peripheral area around the central area. The central area has a first optical path difference giving structure and the peripheral area has a second optical path difference giving structure. The objective optical element gathers the light fluxes passing through the central area and the peripheral area of the objective optical element so as to respectively record and/or reproduce information onto/from an information recording surface of a predetermined optical disc. Furthermore, a focal distance of the objective optical element with respect to the third light flux satisfies a predetermined condition.
摘要:
Provided are an optical pickup apparatus, an objective optical element, and an optical information recording and reproducing apparatus, capable of recording and/or reproducing information in a compatible way to different types of optical discs. The optical pickup apparatus comprises a first light source, a second light source, a third light source, and an objective optical element. The optical surface of the objective optical element has at least two areas of a central area and a peripheral area surrounding the central area, wherein the central area has a first optical path difference giving structure and the peripheral area has a second optical path difference giving structure. The objective optical element focuses the light fluxes passing through its central and peripheral areas on the information recording surfaces of respective prescribed optical discs so that the information can be recorded and/or reproduced. The optical pickup apparatus has such wavelength dependence of spherical aberration that the spherical aberration change caused by the temperature change of the objective optical element is corrected by the temperature dependent wavelength change of the light flux emitted from the first light source.
摘要:
Provided are an optical pickup apparatus, an objective optical element, and an optical information recording and reproducing apparatus, capable of recording and/or reproducing information in a compatible way to different types of optical discs. The optical pickup apparatus comprises a first light source that emits a first light flux, a second light source that emits a second light flux, a third light source that emits a third light flux, and an objective optical element. The optical surface of the objective optical element has at least two areas of a central area and a peripheral area surrounding the central area, wherein the central area has a first optical path difference giving structure and the peripheral area has a second optical path difference giving structure. The objective optical element focuses the light fluxes passing through its central and peripheral areas on the information recording surfaces of respective prescribed optical discs so that the information can be recorded and/or reproduced. The first optical path difference giving structure is formed by superimposing a first basic structure and a second basic structure having respective predetermined structures on each other.
摘要:
An objective lens according to the present invention is an objective lens used for an optical pickup apparatus, and the objective lens includes a superimposed structure on a surface of a lens with a power in which a first optical path difference providing structure changing spherical aberration in under-corrected direction when a wavelength of an incident light flux becomes longer, and a second optical path difference providing structure changing spherical aberration in over-corrected direction when a wavelength of an incident light flux becomes longer are superimposed.
摘要:
An optical pickup device comprising a first light source emitting a first light beam, a second light source emitting a second light beam, a third light source emitting a third light beam, and an objective optical element, wherein the optical surface of the objective optical element has at least two regions, a central region and a peripheral region, the central region has a first optical path difference imparting structure and the peripheral region has a second optical path difference imparting structure, the objective optical element condenses the first light beam, the second light beam and the third light beam passed through the central region, and condenses the first light beam and the second light beam passed through the peripheral region, and the first and second optical path difference imparting structures have a basic structure as a predetermined optical path difference imparting structure, respectively.
摘要:
An optical pickup device comprising a first light source emitting a first light beam, a second light source emitting a second light beam, a third light source emitting a third light beam, and an objective optical element, wherein the optical surface of the objective optical element has at least a central region and a peripheral region, the central region has a first optical path difference imparting structure and the peripheral region has a second optical path difference imparting structure, first best focus and second best focus are formed by the third light beam passed through the first optical path difference imparting structure, a spot central part, a spot middle part and a spot peripheral part are formed in a spot which is formed on the information recording surface of a third optical disk by the third light beam passed through the objective optical element, the spot central part is used for recording and/or reproducing the information on the third optical disk but the spot middle part and the spot peripheral part are not used for recording and/or reproducing the information on the third optical disk, and the spot peripheral part is formed on the information recording surface of the third optical disc by the third light beam passed through the second optical path difference imparting structure.
摘要:
Provided are an optical pickup apparatus, an objective optical element, and an optical information recording and reproducing apparatus, capable of recording and/or reproducing information in a compatible way to different types of optical discs. The optical pickup apparatus comprises a first light source that emits a first light flux, a second light source that emits a second light flux, a third light source that emits a third light flux, and an objective optical element. The optical surface of the objective optical element has at least two areas of a central area and a peripheral area surrounding the central area, wherein the central area has a first optical path difference giving structure and the peripheral area has a second optical path difference giving structure. The objective optical element focuses the light fluxes passing through its central and peripheral areas on the information recording surfaces of respective prescribed optical discs so that the information can be recorded and/or reproduced. The first optical path difference giving structure is formed by superimposing a first basic structure and a second basic structure having respective predetermined structures on each other.
摘要:
Provided are an optical pickup device, an objective optical element, and an optical information recording/reproducing device capable of recording and/or reproducing information to/from optical discs of different types in a compatible manner. The optical pickup device includes a first light source, a second light source, a third light source, and an objective optical element. The objective optical element has an optical surface having at least two areas, i.e., a central area and a peripheral area around the central area. The central area has a first optical path difference giving structure and the peripheral area has a second optical path difference giving structure. The objective optical element gathers the light flux passing through the central area and the peripheral area of the objective optical element so as to respectively record and/or reproduce information onto/from an information recording surface of a predetermined optical disc. Moreover, the first optical path difference giving structure has a coaxial circular band structure having a step and the step difference amount of the first optical path difference giving structure has a predetermined step difference amount.
摘要:
Provided are an optical pickup device, an objective optical element, and an optical information recording/reproducing device capable of recording and/or reproducing information to/from optical discs of different types in a compatible manner. The optical pickup device includes a first light source for emitting a first light flux, a second light source for emitting a second light flux, a third light source for emitting a third light flux, and an objective optical element. The objective optical element has an optical surface having at least two areas, i.e., a central area and a peripheral area around the central area. The central area has a first optical path difference giving structure and the peripheral area has a second optical path difference giving structure. The objective optical element gathers the light fluxes passing through the central area and the peripheral area of the objective optical element so as to respectively record and/or reproduce information onto/from an information recording surface of a predetermined optical disc. Furthermore, a focal distance of the objective optical element with respect to the third light flux satisfies a predetermined condition.
摘要:
An optical pickup device comprising a first light source for outputting a first light beam, a second light source for outputting a second light beam, a third light source for outputting a third light beam, and an objective optical unit having an annular-structure first light path difference imparting structure and an annular-structure second light path difference imparting structure, wherein the magnifications of the objective optical unit when the first, second and third beams are incident to the objective optical unit are almost the same, the first light path difference imparting structure imparts a specified light path difference to the first light beam, and changes the spherical aberrations of all the first light beam, second light beam and third light beam to one of under and over directions, the second light path difference imparting structure imparts a specified light path difference to the first light beam, and changes the spherical aberration of only the second light beam out of the first light beam, second light beam and third light beam to the other direction different from the one of under and over directions.