摘要:
A first phase structure corrects at least one of a spherical aberration due to a difference between a protective substrate thickness t1 and a protective substrate thickness t2 and a spherical aberration due to a difference between a first wavelength λ1 and a second wavelength λ2, and a second phase structure corrects at least one of a spherical aberration generated when the first wavelength λ1 is changed in a range of ±10 nm, a best image point movement generated when the first wavelength λ1 is changed in a range of ±10 nm, and a spherical aberration generated when environmental temperature is changed.
摘要:
An optical system for use in an optical pickup apparatus comprises a first optical surface having a superposition type diffractive structure including a plurality of ring-shaped zones which are formed concentrically around an optical axis, wherein each ring-shaped zone is composed of a plurality of stepped sections stepwise, and a second optical surface having a diffractive structure including a plurality of ring-shaped zones which are formed concentrically around an optical axis, wherein each of the plurality of ring-shaped zones are divided by a stepped section to generate a diffractive light ray of diffractive order whose absolute value is not small than 1 for the light flux.
摘要:
A hybrid objective lens has a refractive lens and a diffractive optical element constructed by plural coaxial ring-shaped zones on at least one optical surface thereof. When n1, n2 and n3 each is a diffraction order of a diffracted ray having a maximum light amount among diffracted rays of each of first, second and third light flux having wavelength λ1, λ2 and λ3 when respective light flux comes to be incident into the diffractive structure respectively, the following formulas are satisfied: |n1|>|n2|, and |n1|>|n3|, and the hybrid objective lens converges a n1-th, n2-th and n3-th order diffracted ray of the first, second and third light flux onto an information recording plane of each of the first, second ant third optical information recording medium respectively so as to form an appropriate wavefront within respective prescribed necessary image side numerical apertures.
摘要翻译:混合物镜具有在其至少一个光学表面上由多个同轴环形区域构成的折射透镜和衍射光学元件。 当n 1,n 2和n 3各自是当各个光束来到时具有波长λ1,λ2和λ3的第一,第二和第三光束中的每一个的衍射光线中具有最大光量的衍射光线的衍射级数 要分别入射到衍射结构中,满足下列公式:<?in-line-formula description =“In-line formula”end =“lead”?> | n 1 |> | n 2 |和| n 1 |> | n 3 |和<?in-line-formula description =“In-line Formulas”end =“tail”?>混合物镜会聚第1,第2和第3 分别将第一,第二和第三光束的次级衍射光线分别放置到第一,第二蚂蚁第三光学信息记录介质中的每一个的信息记录平面上,以便在各个规定的必要图像侧数值孔径内形成适当的波前。
摘要:
An optical pickup apparatus includes first, second and third light sources; a light converging optical system including a first objective optical element and a second objective optical element, wherein the first objective optical element converges the light flux emitted from the first light source on a first information recording surface, the second objective optical element converges the light flux emitted from the third light source on a third information recording surface, and the first objective optical element or the second objective optical element converges the light flux emitted from the second light source on a second information recording surface; a lens holder holding the first objective optical element and the second objective element therein; and a chromatic aberration correcting element which corrects a chromatic aberration caused by a wavelength variation in a light flux emitted by the first light source.
摘要:
A light flux from the first light source forms a converged spot on first optical information recording medium by only a refraction action of the aspheric surface, or by a combination of the refraction action and an optical action given by at least one of the first phase structure and the second phase structure, a light flux from the second light source forms a converged spot on second optical recording medium by a combination of a refraction action of the aspheric surface and an optical action given by at least one of the first phase structure and the second phase structure, and a light flux from the third light source forms a converged spot on third optical recording medium by a combination of a refraction action of the aspheric surface and an optical action given by at least one of the first phase structure and the second phase structure.
摘要:
The lens unit for the optical pick-up apparatus has: the objective lens by which the projecting light from the light source is condensed on the information recording surface of the optical information recording medium; the phase control element which is arranged on the light source side to the objective lens, and which controls the phase of the projecting light from the light source; and the supporting member holding the objective lens and the phase control element; and the phase control element is held under the condition that its optical axis is inclined by a predetermined angle to the optical axis of the objective lens, and the intersection at which the optical axis of the phase control element crosses the optical surface having the phase structure is arranged on the optical path passing through the central point which passes the optical axis of the objective lens.
摘要:
An optical pickup apparatus comprises a first, second and third light beam sources for emitting first light beams having wavelengths λ1, λ2 and λ3 (λ1
摘要:
An optical system for use in an optical pickup apparatus comprises a first optical surface having a superposition type diffractive structure including a plurality of ring-shaped zones which are formed concentrically around an optical axis, wherein each ring-shaped zone is composed of a plurality of stepped sections stepwise, and a second optical surface having a diffractive structure including a plurality of ring-shaped zones which are formed concentrically around an optical axis, wherein each of the plurality of ring-shaped zones are divided by a stepped section to generate a diffractive light ray of diffractive order whose absolute value is not small than 1 for the light flux.
摘要:
A structure according to the present invention is an optical pickup apparatus including a first light source, a second light source, a third light source, a first objective optical system, a second objective optical system, an incidence optical system for emitting the first to third light fluxes into the first objective optical system or the second objective optical system, and an optical detector. The optical pickup apparatus converges a light flux emitted from the first light source onto an information recording surface of a first optical information recording medium or a second optical information recording medium, by using the first objective optical system. The optical pickup apparatus converges a light flux emitted from the second light source onto an information recording surface of a third optical information recording medium by using the second objective optical system, and further converges a light flux emitted from the third light source onto an information recording surface of a fourth optical information recording medium by using the second objective optical system. The first objective optical system includes an objective lens, and a liquid crystal correcting element being adopted to correct the amount of spherical aberration for a light flux passing through the liquid crystal correcting element.
摘要:
An optical system for use in an optical pickup apparatus comprises a first optical surface having a superposition type diffractive structure including a plurality of ring-shaped zones which are formed concentrically around an optical axis, wherein each ring-shaped zone is composed of a plurality of stepped sections stepwise, and a second optical surface having a diffractive structure including a plurality of ring-shaped zones which are formed concentrically around an optical axis, wherein each of the plurality of ring-shaped zones are divided by a stepped section to generate a diffractive light ray of diffractive order whose absolute value is not small than 1 for the light flux.