Abstract: An optical communication module includes a first light-receiving element with a receiving surface in which a light flux with a wavelength ?1 emitted from an end surface of an optical fiber enters; a light-emitting element for emitting a light flux with a wavelength ?2; and a first optical element arranged between the first light-receiving element and the light-emitting element, and the end surface of the optical fiber. The first optical element includes a first optical surface with a positive refractive power and a second optical surface having a diffractive structure. One of the first optical surface and the second optical surface is divided into at least a first optical functional surface and a second optical functional surface through a step difference.

Abstract: An optical pickup apparatus includes: a first light source for emitting a first light flux; a second light source for emitting a second light flux; a third light source for emitting a third light flux; and an objective optical unit having a first optical path difference providing structure and a second optical path difference providing structure. Magnifications of the objective optical unit for the first-third light fluxes have almost same value. The first optical path difference providing structure provides a predefined optical path difference and changes a spherical aberration to be one of under-correction and over-correction for all of the first light flux, the second light flux, and the third light flux. The second optical path difference providing structure provides a predefined optical path difference and changes a spherical aberration to be the other of under-correction and over-correction of the spherical aberration only for the second light flux.

Abstract: An optical system is used in an optical pickup apparatus which conducts reproducing and/or recording information for a first optical disk having a thinner protective substrate t1 [mm] and a second optical disk having a thicker protective substrate t2 [mm]. The optical system comprises a relay lens group comprising at least one movable lens group. The movable lens group moves so that for the first optical disk, a parallel or substantial parallel light flux emitted from the relay lens group enters the objective lens while a divergent light flux emitted from the relay lens group enters the objective. The movable lens group satisfies the following formula: 7.5<=(NA1·?)/(t2?t1)<=22.

Abstract: The present invention relates to a diffractive grating member and to an optical communication module. The optical communication module includes a semiconductor laser;.a coupling optical system for coupling a light flux with a wavelength of ?1 emitted by the semiconductor laser to an optical fiber; and two light-receiving elements for receiving at least two light fluxes each having wavelengths ?2 and ?3 emitted from an end surface of the optical fiber. The coupling optical .system has a diffractive structure, and the coupling optical system changes paths of light fluxes each having wavelengths ?1, ?2 and ?3 into relatively different directions such that the light flux with the wavelength ?1 emitted-by the semiconductor laser enters into the optical fiber and each of the at least two light fluxes each having the wavelengths ?2 and ?3 enters into each of the two light-receiving elements.

Abstract: An objective lens for recording information on and/or reproducing information from an optical information recording medium, comprises a diffractive structure including ring-shaped diffractive zones on at least one surface thereof. The objective lens is a single lens made of plastic material, at least one surface thereof is an aspheric surface, and the following conditional formula is satisfied; NA?0.7 where NA represents an image side numerical aperture necessary for recording on and/or reproducing from an optical information recording medium.

Abstract: Methods and apparatus, including computer program products, for identifying a language corresponding to a string of data include receiving a data string and dividing the data string into coded character sequences for each of a plurality of languages. A length of one or more coded character sequences varies among different languages for coded character sequences having a particular number of characters. The coded character sequences are analyzed to calculate, for each of the plurality of languages, a probability that the data string corresponds to language. The calculated probabilities are compared among the languages, and a language is identified as corresponding to the data string based on the comparison.

Abstract: Methods and apparatus, including computer program products, implementing techniques for reader-specific display of text. The techniques include receiving digital text data comprising base text and annotation text, receiving as input user information about a reader, customizing digital text data according to the user information about the reader, and displaying the customized digital text data. The annotation text includes one or more annotation text elements. The base text includes one or more base text elements. The digital text data associates each annotation text element with a base text element. The user information can include the reader's reading level and reading preferences. Customizing digital text data according to the user information about the reader includes mapping the user's reading level to one of a plurality of character difficulty tables that group the base text elements according to their difficulty level, each character difficulty table corresponding to a particular reading level.

Abstract: An optical scanning device (1) for scanning an information layer (4) of an optical record carrier (2), the device (1) comprising a radiation source (11) for generating a radiation beam (12, 15, 20) and an objective system (18) for converging the radiation beam on the information layer, the information layer being covered by a transparent layer (3) of thickness td and refractive index nd. The objective system comprises a lens having a protection device projecting away from the lens towards the optical record carrier such that the distance between the protection device and the optical record carrier is less than the free working distance. The lens satisfies the condition: where D is the entrance pupil diameter, FWD is the free working distance, and D, FWD, t and td are all expressed in millimeters and where FWD+td/nd<0.51.

Abstract: An objective optical system for use in an optical pickup apparatus which reproduces and/or records information on an information recording surface of first-third optical disks, the objective optical system includes a first optical element, a first part comprising a material A, a second part comprising a material b, wherein the first part and the second part are laminated on the first optical element in an optical axis of the objective optical system, and the material A and the material B have different Abbe constants for d-line each other and a first phase structure formed on a boundary between the first part and the second part.

Abstract: An optical pickup apparatus comprising: a first, second and third light sources emitting first, second and third light flux having first wavelength of ?1, second wavelength of ?2 and third wavelength of ?3, respectively; and an objective optical system converging the first, second and third light fluxes onto an information recording surface of a first, second and third optical disk, respectively, wherein the objective optical system has a phase structure, and wherein when a first, second and third magnifications of the objective optical system for conducting reproducing information from and/or recording information on the first, second and third optical disks are represented by M1, M2, and M3, respectively, |dM1?M2|, which represents an absolute value of a difference between M1 and M2, satisfies the following relation. |dM1?M2|<0.

Abstract: An image pickup apparatus comprises a substrate; an image pickup element to convert a converged light flux to electronic signals; an image-taking optical element positioned so as to converge a light flux from an object onto the image pickup element; a light shielding member to house the image pickup element and the image-taking optical element; a controlling device to control an output of the electronic signals and controlling the image pickup element; and a refracting power-variable optical element.

Abstract: An optical pickup apparatus includes: first-third light sources; a packaged multiple light source unit for packaging emitting points of at least two of the first-third light sources in one housing; an objective optical system for converging light fluxes emitted by light sources onto information recording surfaces of at least three kinds of optical disks; and a magnification adjusting optical unit having an actuator and a movable lens group and being arranged in an optical path between the packaged multiple light source unit and the objective optical system, wherein the movable lens group is driven by the actuator along the optical axis so as to change a magnification of the objective optical system according to a wavelength of a light flux emitted by the packaged multiple light source unit.

Abstract: An objective lens for recording and/or reproducing an optical information recording medium, comprises a first lens having a positive refractive power; and a second lens having a positive refractive power; wherein the first lens and the second lens are aligned in this order from a light source side of the objective lens; first lens and the second lens are respectfully made of material having a specific gravity of 2.0 of less and the objective lens satisfies the following conditional formula: NA?0.70, where NA: a predetermined image side numerical aperture necessary for recording and/or reproducing of the optical information recording medium.

Abstract: An optical pick-up system comprising: a first light source for projecting a first light flux having a wavelength of not more than 450 nm; a second light source for projecting a second light flux having a wavelength within a range of 630 nm to 680 nm; an objective optical system for converging the first light flux on a first optical disk, and for converging a second light flux on a second optical disk, and having at least a plastic lens having a positive refractive power, and wherein a ratio ?SA/?T of a change of a spherical aberration to a temperature change satisfies the following expression (1); and an aberration correction optical system arranged in an optical path between the first light source and the objective optical system, and having a plastic lens having a positive refractive power and a glass lens.

Abstract: An optical system for use in an optical pickup device for recording and/or reproducing information on an optical recording media, the optical system having an optical axis and comprising: an objective system for converging a light beam emitted from a light source on the optical recording media; an optical aberration correcting element comprising two lenses arranged on an optical path between the light source and the objective system and having an adjustable distance in the direction of the optical axis, the optical aberration correcting element comprising a ring-shaped phase structure formed in at least one lens surface of the optical aberration correcting element, and wherein the ring shaped phase structure is non-periodic and comprises a plurality of concentric ring surfaces k (k=1 . . . N), and each of the ring surfaces has a step in the direction of the optical axis between the adjacent ring surface.

Abstract: An optical system utilized in an optical pickup apparatus comprising: an aberration-correcting element made of a plastic material; and a converging lens to converge a light flux emitted from the aberration-correcting element, the converging lens being made of a plastic material, wherein the aberration-correcting element has a first optical surface provided thereon an optical path difference generating structure and has a second optical surface provided thereon a diffractive structure, and the converging lens is a single refractive lens having at least an aspherical surface.

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-shape 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 image pickup apparatus comprises a substrate; an image pickup element to convert a converged light flux to electronic signals; an image-taking optical element positioned so as to converge a light flux from an object onto the image pickup element; a light shielding member to house the image pickup element and the image-taking optical element; a controlling device to control an output of the electronic signals and controlling the image pickup element; and a refracting power-variable optical element.

Abstract: This invention is directed to an optical pickup apparatus which includes a first laser source which emits a first beam, a second laser source which emits a second beam having a polarization plane substantially perpendicular to a polarization plane of the first beam, a polarization diffraction element which selectively diffracts one of the first beam and the second beam in accordance with polarized states thereof, and an objective lens which records and/or reproduces information by focusing the first beam which has passed through the polarization diffraction element onto an information recording surface of a first optical information recording medium, and records and/or reproduces information by focusing the second beam which has passed through the polarization diffraction element onto an information recording surface of a second optical information recording medium.

Abstract: An optical pickup apparatus includes