Abstract: 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.

Abstract: An optical pickup apparatus comprises a first light source for emitting a first light flux having first wavelength ?1 (430 nm>?1>380 nm), a second light source for emitting a second light flux having second wavelength ?2 (?2>?1), an objective optical system having phase structure thereon, and at least one moving optical element for guiding the light flux into the objective optical system, the moving optical element being moved in a direction parallel to an optical axis corresponding to the first light wavelength ?1 and the second light wavelength ?2, wherein the objective optical system has phase structure and satisfies M1=M2=0, where, M1 and M2 denote a first and second magnifications of the objective optical system for recording and/or reproducing the information on or from the first and second optical information media.

Abstract: An objective lens used for an optical pickup device wherein the optical pickup device includes: light source; and a converging optical system including the objective lens for converging a light beam emitted from the light source to an information recording surface of an optical information recording medium, and the optical pickup device is capable of recording and/or reproducing information by converging the light beam emitted from the light source to the information recording surface of the optical information recording medium with the converging optical system, the objective lens being a plastic single lens and satisfying following formulas when NA is an image-side numerical aperture required for recording and/or reproducing information to the optical information recording medium and f (mm) is a focal length of the objective lens.

Abstract: An optical pickup apparatus for conducting recording and/or reproducing information for a first optical information recording medium including at least a transparent protective substrate, a first information recording surface, and a second information recording surface which are laminated in this order from a light source side along an optical axis, comprising: a first light source to emit a light flux having a wavelength of ?1 (380 nm??1?450 nm); an objective lens to converge the light flux onto the first optical information recording medium; a spherical aberration correcting structure to correct a spherical aberration caused in a converged spot on the first and second information recording surfaces due to a difference in thickness between the thickness to the first information recording surface and the thickness to the second information recording surface.

Abstract: 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 ?1 and a second wavelength ?2, and a second phase structure corrects at least one of a spherical aberration generated when the first wavelength ?1 is changed in a range of ±10 nm, a best image point movement generated when the first wavelength ?1 is changed in a range of ±10 nm, and a spherical aberration generated when environmental temperature is changed.

Abstract: 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 ?1, ?2 and ?3 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.

Abstract: Disclosed is a semiconductor device for performing wireless communication, including a wireless transmitting and receiving unit that transmits and receives a wireless signal, and an external interface unit that transmits and receives a signal to and from an external apparatus connected to the semiconductor device at a signal voltage larger than that of the wireless signal transmitted and received by the wireless transmitting and receiving unit. The wireless transmitting and receiving unit and the external interface unit mutually operate in a time-exclusive way.

Abstract: An optical element for use in an optical pickup device to conduct reproducing and/or recording information for a first disk including a protective substrate by the use of a first light flux emitted from a first light source and to conduct reproducing and/or recording information for a second disk including a protective substrate by the use of a second light flux emitted from a first light source, the optical element includes: an optical surface on which a first phase structure is formed to have a function to correct a spherical aberration; an optical surface on which a second phase structure is formed such that when the wavelength of the first light flux changes, the second phase structure generates a spherical aberration in a direction reverse to the direction of a spherical aberration generated by the first phase structure.

Abstract: 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.

Abstract: An objective lens for an optical pickup apparatus is disclosed that can record and/or reproduce information compatibly for different optical discs with stability regardless of an environmental temperature change, in spite of its simple structure, and provides an optical pickup apparatus employing the objective lens. The objective lens includes: an optical surface which at least includes a central area, a peripheral area, and a most peripheral area. The objective lens is a single lens formed of plastic. The central area includes a first optical path difference providing structure. The peripheral area includes a second optical path difference providing structure. The objective lens further includes an optical path difference providing structure for correcting a temperature characteristic, where the optical path difference providing structure corrects an aberration caused by a temperature change of the objective lens.

Abstract: An optical element for optical pickup device is provided with an optical path difference providing structure which provides a substantial phase change to a light flux having a predefined wavelength. The optical path difference providing structure is provided with a step portion having a smaller step difference than the predefined wavelength in an optical axis direction.

Abstract: There are provided an objective lens for an optical pickup device which can record and/or reproduce information on/from an optical disk with high density with the use of a light flux with a short wavelength while keeping a temperature characteristic to be satisfactory in spite of having a plastic objective lens, and the optical pickup device. The objective lens suppresses generation of a spherical aberration even if a temperature change arises, by sacrificing wavelength characteristics and by enhancing temperature characteristics. Such satisfactory temperature characteristics can be acquired by the ring-shaped structure formed as a turning structure on an optical surface of the objective lens, in which the ring-shaped structure includes ring-shaped zones whose number is 3 or more and 30 or less and the ring-shaped structure is formed such that adjoining ring-shaped zones cause a predetermined optical path difference for an incident light flux.

Abstract: There are provided an optical pickup device which can satisfactorily record and/or reproduce information on different kinds of optical information recording medium in spite of compactness, and an objective optical element used for the optical pickup device. The optical functional surface of the objective optical element includes at least two areas of a central area including an optical axis and a peripheral area surrounding the central area. An optical path difference providing structure in the central area is a structure obtained by overlapping a first central basic structure and a second central basic structure which are in a shape of ring-shaped zones divided by step differences, with each other. An optical path difference providing structure in the peripheral area is a structure obtained by overlapping a first peripheral basic structure and a second peripheral basic structure which are in a shape of ring-shaped zones divided by step differences, with each other.

Abstract: 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.

Abstract: A communication network of the present invention includes: a plurality of superordinate nodes 110 to 1m0 forming a cascade type topology; and a plurality of terminal nodes 111 to 11n, connected to at least one superordinate node from among said plurality of superordinate nodes and forming a star type topology with the superordinate node connected.

Abstract: An optical element for an optical pickup device which can record and/or reproduce information interchangeably with an optical disc while correcting coma satisfactorily, and a compact optical pickup device employing that optical element and exhibiting excellent energy saving. In the optical element for an optical pickup device where a first objective lens portion and a second objective lens portion are formed integrally, one of the first objective lens portion and the second objective lens portion satisfies a relation |HCM|/|TCM|<0.3 and the other satisfies a relation |HCM|/|TCM|>0.3. The HCM represents the third-order angle of view coma sensitivity in the first objective lens portion or the second objective lens portion, and the TMC represents the third-order inclination angle coma sensitivity in the first objective lens portion or the second objective lens portion.

Abstract: An objective lens used for an optical pickup device wherein the optical pickup device includes: light source; and a converging optical system including the objective lens for converging a light beam emitted from the light source to an information recording surface of an optical information recording medium, and the optical pickup device is capable of recording and/or reproducing information by converging the light beam emitted from the light source to the information recording surface of the optical information recording medium with the converging optical system, the objective lens being a plastic single lens and satisfying following formulas when NA is an image-side numerical aperture required for recording and/or reproducing information to the optical information recording medium and f (mm) is a focal length of the objective lens.

Abstract: An objective lens according to the present invention is an objective lens used for an optical pickup apparatus, and the objective lens includes a superimposed structure on a surface of a lens with a power in which a first optical path difference providing structure changing spherical aberration in under-corrected direction when a wavelength of an incident light flux becomes longer, and a second optical path difference providing structure changing spherical aberration in over-corrected direction when a wavelength of an incident light flux becomes longer are superimposed.

Abstract: An objective lens according to the present invention is an objective lens used for an optical pickup apparatus, and the objective lens includes a superimposed structure on a surface of a lens with a power in which a first optical path difference providing structure changing spherical aberration in under-corrected direction when a wavelength of an incident light flux becomes longer, and a second optical path difference providing structure changing spherical aberration in over-corrected direction when a wavelength of an incident light flux becomes longer are superimposed.

Abstract: 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.