摘要:
An information-recording medium of write once or rewritable type designed to have narrow tracks is provided, in which the wobble signal amplitude is scarcely fluctuated by crosstalk. The medium includes recording tracks formed in a spiral form and meandering at a predetermined wobble cycle T, and a plurality of zones constituting each of the recording tracks, each of the zones having a principal area formed to have a predetermined wobble phase. A relationship of T>80b holds between the wobble cycle T and a channel bit length b of recording data. The wobble phase of one of the recording tracks is adjusted so that an average phase difference d is d>π/2 between the wobble phase in the principal area in the zone and a wobble phase of an area in the recording track disposed adjacently on an inner circumferential side or an outer circumferential side of the principal area, in relation to all of the recording tracks disposed adjacently in the radial direction.
摘要:
A pickup lens with a phase compensator is composed of a condenser lens and a phase compensator. At least one surface of the condenser lens has a step-like annular zone structure to compensate wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t1 with a laser beam having a wavelength λ1 and wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t2 with a laser beam having a wavelength λ2. The phase compensator compensates wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t3 with a laser beam having a wavelength λ3.
摘要:
A pickup lens with a phase compensator is composed of a condenser lens and a phase compensator. At least one surface of the condenser lens has a step-like annular zone structure to compensate wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t1 with a laser beam having a wavelength λ1 and wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t2 with a laser beam having a wavelength λ2. The phase compensator compensates wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t3 with a laser beam having a wavelength λ3.
摘要:
A pickup lens with a phase compensator is composed of a condenser lens and a phase compensator. At least one surface of the condenser lens has a step-like annular zone structure to compensate wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t1 with a laser beam having a wavelength λ1 and wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t2 with a laser beam having a wavelength λ2. The phase compensator compensates wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t3 with a laser beam having a wavelength λ3.
摘要:
An objective lens optical system includes a light beam splitting element and an objective lens and is configured to focus a light beam with a wavelength λ on an information recording surface of a first optical recording medium as a dual/double layer disc having a transparent substrate with a thickness t1 and to focus a light beam with a wavelength λ on an information recording surface of a second optical recording medium as a dual/double layer disc having a transparent substrate with a thickness t2 (t1
摘要:
An objective lens optical system focuses a light beam with a wavelength λ1 on an information recording surface of a first optical recording medium including a transparent substrate with a thickness t1, a light beam with the wavelength λ1 on an information recording surface of a second optical recording medium including a transparent substrate with a thickness t2, and a light beam with a wavelength λ3 on an information recording surface of a third optical recording medium including a transparent substrate with a thickness t3, by using a refraction action. Sectioning the area of the objective lens optical system is applied to a compatible technique for the same wavelengths, and generating an aberration for canceling a chromatic aberration caused by a difference in wavelength λ of the light beam is applied to a compatible technique for different wavelengths.
摘要:
There is provided an optical pickup system which includes a first light source emitting first light having a wavelength λ1, a second light source emitting second light having a wavelength λ2 longer than the wavelength λ1, a third light source emitting third light having a wavelength λ3 longer than the wavelength λ2, and an objective lens focusing the first light on an information recording surface of a first optical recording medium, focusing the second light on an information recording surface of a second optical recording medium, and focusing the third light on an information recording surface of a third optical recording medium. In the optical pickup system, at least one lens surface of the objective lens is divided into a plurality of concentric sections with an optical axis, having a step at each boundary between the sections, each of the sections has a different aspherical shape and m1>m2>0 and −0.060≦m3≦−0.020 are satisfied where an imaging magnification at the first light is m1, an imaging magnification at the second light is m2, and an imaging magnification at the third light is m3 in the objective lens. This enables a decrease in aberration at the first light and the second light and an increase in object distance at the third light. Further, this step enables the shared use of a photodetector for detecting the first light and a photodetector for detecting the second light.
摘要:
A pickup lens with a phase compensator is composed of a condenser lens and a phase compensator. At least one surface of the condenser lens has a step-like annular zone structure to compensate wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t1 with a laser beam having a wavelength λ1 and wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t2 with a laser beam having a wavelength λ2. The phase compensator compensates wavefront aberration generated when recording and reproducing data on an information recording medium having a substrate thickness of t3 with a laser beam having a wavelength λ3.
摘要翻译:具有相位补偿器的拾取镜头由聚光透镜和相位补偿器组成。 聚光透镜的至少一个表面具有阶梯状环形区域结构,以补偿在具有波长λ1和波前像差的激光束在基板厚度为t 1的信息记录介质上记录和再现数据时产生的波前像差 在具有波长λ2的激光束的基板厚度为t 2的信息记录介质上记录和再现数据时产生的相位补偿器补偿当在具有基板厚度的信息记录介质上记录和再现数据时产生的波前像差 t 3具有波长λ3的激光束。