摘要:
There is provided an objective lens for information recording/reproducing for three types of optical discs, which includes a first area contributing to converging a third light beam onto a record surface of a third optical disc. The first area includes a phase shift structure having refractive surface zones concentrically formed about a predetermined axis. The phase shift structure includes first and second step groups. The first step group is configured such that an optical path length difference ΔOPD1 (nm) given by each step of the first step group to a first light beam satisfies a condition: 2N1+1.10
摘要:
There is provided an objective lens used for an optical information recording/reproducing device for recording information to and/or reproducing information from two types of optical discs, by selectively using one of two types of substantially collimated light beams including first and second light beams. When wavelengths of the first and second light beams are respectively represented by λ1 (nm) and λ2 (nm), λ1
摘要:
An objective optical system for information recording/reproducing, at least one of optical surfaces of the objective optical system comprising a diffraction surface including a first region contributing to converging first, second and third beams and including a diffraction structure formed such that use diffraction orders for the first, second and third beams are 1st-orders and a condition 0.03
摘要:
There is provided an objective optical system including an optical element having a phase shift structure, and a single-element objective lens made of resin, wherein the phase shift structure includes a plurality of refractive surface zones, the phase shift structure includes a first area to contribute to converging at least the third light beam on a record surface of the third optical disc, the first area includes at least two types of steps, each of which is formed at a boundary between adjacent ones of the plurality of refractive surface zones, the at least two types of steps gives optical path length differences different from each other to an incident light beam, the annular zone structure satisfies following conditions: 0.01
摘要:
An optical pickup device includes a first light source emitting first light with a first wavelength, a second light source emitting second light with a second wavelength, a third light source emitting third light with a third wavelength, an objective lens having a step structure, the objective lens being disposed to satisfy predetermined conditions, at least one first coupling lens making the first light and the second light incident onto the objective lens as converged light, a second coupling lens making the third light incident onto the objective lens as diverging light, and a liquid crystal aberration correcting element.
摘要:
There is provided an objective lens used for a plurality of types of optical discs having a front surface and a rear surface, each of which includes an inner region and an outer region. The outer region has a surface shape which suppresses a coma caused when a beam used for a first optical disc is incident thereon obliquely with respect to an optical axis of the objective lens. The inner region is configured such that, at a boundary position between the inner region and the outer region, the coma caused when a beam used for a second optical disc is incident on the inner region obliquely at a first angle with respect to the optical axis is less than the coma caused when the beam used for the second optical disc is incident on the outer region obliquely at the first angle with respect to the optical axis. Further, an inclination θ2A of the inner region and an inclination θ2B of the outer region of the rear surface satisfy a condition: −2.5
摘要:
There is provided an optical pick-up including first to third light sources respectively emitting first to third light beams, a first coupling lens, and an objective lens formed to converge each of the first, second and third light beams onto the first, second and third optical discs, respectively. The objective lens has a step structure including a plurality of concentrically formed refractive surface zones divided by steps, the step structure having a function of giving, at each step, an optical path length difference of approximately 2λ1 to the first light beam. The first coupling lens causes the first light beam to be incident on the objective lens as a converging beam. The objective lens is positioned to satisfy a condition: −0.35
摘要:
An objective lens for an optical information recording/reproducing device (executing information reading or writing on first through third optical discs having different data densities and different protective layer thicknesses t1-t3 (t1≦t2≦t3)) by selectively using first through third substantially collimated light beams having first through third wavelengths λ1-λ3 (λ1 m(λ2)≧m(λ3)≧1.
摘要翻译:用于光学信息记录/再现装置的物镜(执行具有不同数据密度和不同保护层厚度t 1 -t 3(t 1 <= t 2 <= t 3)的第一至第三光盘的信息读取或写入) 通过选择性地使用具有第一至第三波长λ1-λ3(λ1<λ3)的第一至第三基本上准直的光束)包括在固结表面处胶合在一起的第一光学构件和第二光学构件。 在固定数值孔径NA 3所需的入射高度(在第三光盘上进行信息读/写所需)的入射高度的至少一个区域设置有包括环形区域的衍射结构。 衍射结构形成为使得其衍射效率最大化的第一至第三光束的衍射级m(λ1),m(λ2)和m(λ3)满足m(λ1)> m(λ2)> = m(λ3)> = 1。
摘要:
An objective lens, for an optical information read/write device that performs read/write operations on each of a plurality of optical discs using a corresponding one of three laser beams having first, second, and third wavelengths λ1, λ2, and λ3 (nm) satisfying a relationship λ1
摘要:
There is provided an objective optical system used for information recording/reproducing for three types of optical discs. The objective optical system includes an objective lens, and a diffraction structure formed on an optical surface. The diffraction structure includes a first area for contributing to converging the third light beam. The first area includes first and second steps defined by first and second optical path difference functions, respectively. The first step is configured such that diffraction orders at which diffraction efficiencies for the first, second and third light beams are maximized are 1st order, 0-th order and 0-th order, respectively. The first step satisfies a condition: −0.36×102