Abstract:
A coma compensating element has two refraction surfaces. The refraction surfaces provide, as a whole, no aberration with respect to rays perpendicularly incident thereon, while the refraction surfaces provide coma with respect to rays obliquely incident thereon.
Abstract:
An objective lens used for recording data to and/or reproducing data from a plurality of types of optical discs having different thicknesses of cover layers. The objective lens satisfies a condition 0.02
Abstract:
In a scanning optical system where a bundle of rays scans a surface to be scanned through an optical deflector and an image forming optical system, the image forming optical system includes a positive front lens group having two lens elements and a rear lens group constituted by an elongated single anamorphic lens element having a strong positive refractive power in the sub scanning direction. All the lens elements in the image forming optical system are made of a resin material, and the scanning optical system satisfies the conditions: (1)d.sub.0 /f
Abstract translation:在其中一束光线通过光学偏转器和成像光学系统扫描要扫描的表面的扫描光学系统中,图像形成光学系统包括具有两个透镜元件的正面前透镜组和由 在副扫描方向上具有强正折射力的细长单变形透镜元件。 图像形成光学系统中的所有透镜元件由树脂材料制成,并且扫描光学系统满足以下条件:(1)d0 / f <0.23(2)0.70
Abstract:
A polyurethane resin composition without handling trouble is obtained by a combination of a copolyether polyol obtained by copolymerization of tetrahydrofuran and a 3-alkyl tetrahydrofuran at a mixing molar ratio of 85/15-20/80, a polyisocyanate compound and an active hydrogen atom-containing compound. The 3-alkyl tetrahydrofuran is preferably 3-methyl tetrahydrofuran.
Abstract:
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
Abstract:
An optical information recording/reproducing apparatus for an optical disc using a light beam having a wavelength of λ including: an objective lens that converges the light beam onto a recording surface of the optical disc and satisfies a condition: 0.48
Abstract:
A multichip module includes a package substrate, a first semiconductor device, a second semiconductor device and a conductive bump. The first semiconductor device is flip-chip bonded to the package substrate. The first semiconductor device includes a first chip pad on a surface thereof. The second semiconductor device is mounted on the first semiconductor device. The second semiconductor device includes a second chip pad facing the first chip pad. The conductive bump connects the first chip pad to the second chip pad. The conductive bump includes a first metallic body that has a first diffusion rate and a second metallic body that has a second diffusion rate lower than the first diffusion rate.
Abstract:
A rotational angle detector provided with a circular rotary plate integrally rotatable with a rotor of a motor and including a circumferential surface having marks, which are spaced apart by different angular intervals in a circumferential direction. A rotational angle detection unit is arranged along the circumferential direction of the rotary plate to detect a rotational angle of each mark, rotated together with the rotary plate, in a predetermined detection zone. The rotational angle detector determines, when adjacent marks are located in the detection zone, angular intervals between the adjacent marks based on the rotational angle of each mark, specifies a mark that is located in the detection zone based on the determined angular intervals, and detects the rotational angle of the rotor based on the rotational angle of the specified mark rotating in the detection zone.
Abstract:
An objective optical system for an optical information recording/reproducing apparatus, at least one surface of the objective optical system being configured to be a phase shift surface having a phase shift structure, wherein: the phase shift surface has a first area contributing to converging first, second and third light beams onto recording surfaces of first, second and third optical discs, respectively; in the first area, the phase shift surface has at least two types of phase shift structures including a first phase shift structure having first steps and a second phase shift structure having second steps; the phase shift surface has a plurality of combinations of annular zones which satisfy a condition: 0.95
Abstract:
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