Abstract: An objective lens element which can obtain appropriate spot performance only by simple position adjustment, and an optical pickup device using the objective lens element are provided. In the objective lens element, an amount of a generated third-order astigmatism of a spot which is formed when symmetry axes of optically functional surfaces are located parallel to the normal line of a base plate and an incident light beam incident such that a central light beam thereof is tilted at 0.5 degree with respect to the normal line of the base plate is converged, is reduced to be less than an amount of a generated spherical aberration of a spot which is formed when the symmetry axes of the optically functional surface are located parallel to the normal line of the base plate and an incident light beam incident parallel to the normal line of the base plate is converged.

Abstract: An optical element which can be shared by three wavelengths for BD, DVD, and CD and which is easily manufactured is provided. An objective lens system includes an optical element 1A and a converging lens element 1B. A first surface of the optical element 1A on an incident side is concentrically divided into a region 11 including a rotational symmetry axis, a region 12, and a region 13. On the optical element 1A, a periodic stair-like diffraction structure and a periodic sawtooth-like diffraction structure are provided. A second surface of the optical element 1A is divided into a region 21 including a rotational symmetry axis, a region 22, and a region 23. On the region 21, a sawtooth-like diffraction structure is provided. The converging lens element 1B converges light having passed through the optical element 1A, to form a spot on an information recording surface of an optical disc.

Abstract: An optical element which has optical steps each providing a phase difference to transmitted light and has low light amount loss and a high efficiency is provided. The optical element includes a symmetry axis, a plurality of optically functional surfaces which are ring-shaped regions around the symmetry axis, and a plurality of wall regions connecting the optically functional surfaces to each other. The optically functional surfaces and the wall regions constitute the optical steps. On a cross-section taken by, as a cutting plane, a plane including the symmetry axis, the contour line of each wall region is substantially parallel to a light beam which is incident on the optically functional surface on the outer side and passes near the wall region. The maximum value of the angle between the symmetry axis and the light beam passing near the wall region is equal to or more than 25 degrees.

Abstract: The present invention relates to a structure comprising: a resin pattern (A)3 formed on a base material 1 and having structure units of a predetermined shape; and a resin pattern (B)5 formed on a surface of the resin pattern (A)3 and having microscopic structure units, of a predetermined shape, arranged at a period shorter than or equal to a wavelength range of a using light, and to a method for producing the structure, comprising the steps of: (i) forming a resin layer 2 on the base material 1 and subjecting the resin layer 2 to an exposure-development process so as to form the resin pattern (A)3; and (ii) subjecting a surface of the resin pattern (A)3 to an exposure-development process so as to form the resin pattern (B)5, wherein the steps (i) and (ii) are sequential.

Abstract: An optical head device compatible to different types of optical discs and capable of guaranteeing a sufficiently wide dynamic range for a low density optical disc, and the like are provided. The optical head device includes a plurality of light sources switchably usable; an objective lens for converging light emitted from one of the plurality of light sources to an information recording layer of an optical disc; and a light detector for receiving the light reflected by the information recording layer and outputting an electric signal based on the amount of the received light. The plurality of light sources include a first light source for emitting light having a first wavelength and a second light source for emitting light having a second wavelength shorter than the first wavelength.

Abstract: An optical system for optical pickup, which optical system is used for performing recording, reproducing, and/or erasing of information on an optical recording medium and has a simple configuration, is provided. An optical pickup device 1 includes a collimator lens system 23, a beam expander 33, and an objective lens system 34 that includes an S-SIL element 27b. The beam expander 33 includes three lens elements 33a to 33c. By moving in an optical axis direction, the two lens elements 33a and 33b included in the beam expander 33 adjust a focal point of a spot formed within an optical recording medium 28, and compensate a spherical aberration caused by the difference in depth between recording layers.

Abstract: An optical pickup device is provided which is compatible with at least two types of optical disc standards having different NAs and which controls an effective NA when a light beam for an optical disc standard having a relatively small NA is converged, thereby forming a desired spot. An inner part 131B and an outer part 131F of an objective lens element 143 are provided with diffraction structures different from each other. A condition (1), DO11×DO12>0, and a condition (2), DO21×DO22<0, are satisfied (DO11(DO21) is the diffraction order of the diffracted light beam having the highest diffraction efficiency among light beams of the wavelength ?1(?2) diffracted by the diffraction structure on the inner part; and DO12 (DO22) is the diffraction order of the diffracted light beam having the highest diffraction efficiency among light beams of the wavelength ?1 (?2) diffracted by the diffraction structure on the outer part).

Abstract: An objective lens element that can suppress occurrence of an aberration is disclosed. Sawtooth-like diffraction structures having different height and cycles (pitches) are provided on an inner part R21 and an outer part R22, respectively. A curved surface M211 extending at an intermediate level of recesses and projections of the sawtooth-like diffraction structure provided on the inner part R21, and a curved surface M212 extending at an intermediate level of recesses and projections of the sawtooth-like diffraction structure provided on the outer part R22 are smoothly connected to each other. Even when wavelength of the light source and/or the environmental temperature change, a phase shift does not occur between the inner part R21 and the outer part R22, and a decrease in diffraction efficiency and occurrence of an aberration can be suppressed.

Abstract: A compound objective lens, an optical head device, an optical information device, and an information processing device that can inhibit the occurrence of aberration even when a light beam source wavelength shifts from the designed value. A diffraction structure having a sawtooth or stepwise cross section is formed in the region (R10) and region (R20). The height of the sawtooth or stepwise cross section formed in the region (R10) provides a light beam, which has a predetermined wavelength, with a difference in optical path length of N times the predetermined wavelength, as compared with a case of propagation in air. The height of the sawtooth or stepwise cross section formed in the region (R20) provides the light beam, which has the predetermined wavelength, with a difference in optical path length of J times the predetermined wavelength, as compared with a case of propagation in air.

Abstract: An optical head device compatible to different types of optical discs and capable of guaranteeing a sufficiently wide dynamic range for a low density optical disc, and the like are provided. The optical head device includes a plurality of light sources switchably usable; an objective lens for converging light emitted from one of the plurality of light sources to an information recording layer of an optical disc; and a light detector for receiving the light reflected by the information recording layer and outputting an electric signal based on the amount of the received light. The plurality of light sources include a first light source for emitting light having a first wavelength and a second light source for emitting light having a second wavelength shorter than the first wavelength.

Abstract: An object of the present invention is to reduce the influence of a stray light incident on a light receiving device by reflection of an unnecessary diffraction light not contributing to write or read on a disc surface at write or read of an optical disc having a large surface reflectivity with respect to an information recording surface. A position in which a diffraction light with an n-order in an advancing path and the n-order in a returning path, reflected on the information recording surface of a first information recording medium, is focused by a condensing lens is different from a position in which a diffraction light different from the n-order diffraction light in at least one of the advancing path and the returning path, reflected on a surface of the first information recording medium, is focused by the condensing lens.

Abstract: An ice making method and device may include an ice making member inserting step in which an ice making member is inserted into water that is stored in an ice tray, an ice pieces making step in which the ice making member is cooled so that the water is frozen to form an ice pieces, an ice making member heating step in which the ice making member is heated so that a portion of the ice pieces sticking to the ice making member is melted, an ice making member drawing-out step in which the ice making member is drawn out from the ice pieces, and an ice pieces separating step in which the ice tray is deformed to separate the ice pieces from the ice tray. The ice pieces separating step and the ice pieces storing step are performed at positions under the ice making member.

Abstract: A method for controlling the pluripotent phenotype of a cell comprising modulating the expression or activity of a ESET/SETDB1 polypeptide, or a homologue thereof, within the cell is provided. Pluripotent cells, cultures of such cells and methods for reprogramming somatic cells to a pluripotent phenotype comprising expressing a ESET/SETDB1 polypeptide in the cells, either alone or in combination with other pluripotency factors, are further provided. Methods for identifying modulators of pluripotency and their use in treating cancer or cancer stem cells are also provided.

Abstract: An optical head device compatible to different types of optical discs and capable of guaranteeing a sufficiently wide dynamic range for a low density optical disc, and the like are provided. The optical head device includes a plurality of light sources switchably usable; an objective lens for converging light emitted from one of the plurality of light sources to an information recording layer of an optical disc; and a light detector for receiving the light reflected by the information recording layer and outputting an electric signal based on the amount of the received light. The plurality of light sources include a first light source for emitting light having a first wavelength and a second light source for emitting light having a second wavelength shorter than the first wavelength.

Abstract: An object of the present invention is to reduce the influence of a stray light incident on a light receiving device by reflection of an unnecessary diffraction light not contributing to write or read on a disc surface at write or read of an optical disc having a large surface reflectivity with respect to an information recording surface. A position in which a diffraction light with an n-order in an advancing path and the n-order in a returning path, reflected on the information recording surface of a first information recording medium, is focused by a condensing lens is different from a position in which a diffraction light different from the n-order diffraction light in at least one of the advancing path and the returning path, reflected on a surface of the first information recording medium, is focused by the condensing lens.

Abstract: Provides a coupling lens which, when used in combination with an objective lens for a plurality of types of optical discs such as a high density disc, DVD, CD or the like, is capable of compensating for various types of aberrations including those caused by wavelength changes and thus providing good recording or reproduction characteristics with a good wavelength dispersion compensation ability; and an optical head and an optical disc apparatus (drive). A coupling lens is incorporated into an optical head for collecting laser light emitted from a plurality of light sources and having different wavelengths on an information recording face of different types of optical information recording mediums respectively. The coupling lens comprises a first lens and a second lens which are substantially in close contact with each other such that optical axes thereof match each other and designed such that the laser light having different wavelengths are refracted by the close contact face.

Abstract: An objective lens for converging light onto a recording surface of an optical information recording medium in order to perform at least one of recording, reproduction and deletion of information on the optical information recording medium. The objective lens is a bi-convex single lens having at least one aspheric surface, and satisfies the following conditions: 0.8<R1/r1<0.85 and 0.9<d/f<1.1. Here, a numerical aperture NA on the optical information recording medium side of the objective lens satisfies NA?0.85. R1 is a paraxial curvature radius [mm] on a light source side of the objective lens, r1 is an effective radius [mm] on a light source side of the objective lens, d is a thickness [mm] on the optical axis of the objective lens, and f is a focal length [mm] of the objective lens.

Abstract: A complex optical element includes a first optical portion and a second optical portion which are made of materials different from each other. The second optical portion is bonded to an optical functional face of the first optical portion. A concavoconvex face part is formed at the central part of the bond area between the first optical portion and the second optical portion.

Abstract: A diffractive optical element includes a first optical part and a second optical part bonded to each other with a bonded surface therebetween configured as a diffraction surface. In this diffractive optical element, the diffraction order of diffracted light with the largest quantity of light out of diffracted light for one of a plurality of kinds of laser beams obtained on the diffraction surface is different from the diffraction order for at least another laser beam.

Abstract: In order that thickness reduction, weight reduction, and mass productivity improvement should be achieved in an objective lens even in the case where NA is high, an objective lens according to the present invention is a bi-convex single lens having at least one aspheric surface, and satisfies conditions: (1) 3.5<DH-S/DH-H?<4.3; (2) 3.5<DH?-T2/DT1-H<50; (3) 0.9<d/f<1.1 (NA?0.85).