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Hideaki Hirai, Kanagawa JP

Hideaki Hirai, Kanagawa JP

Patent application numberDescriptionPublished
20090097381OPTICAL PICKUP AND OPTICAL INFORMATION PROCESSING APPARATUS - A disclosed optical pickup for performing at least recording, reproduction, or deletion of information on a first, second, third, and fourth optical recording media having different recording densities includes a first light source configured to emit first light having a first wavelength λ04-16-2009
20100014073OPTICAL ELEMENT, REFRACTIVE INDEX SENSOR, REFRACTIVE INDEX SENSOR ARRAY, AND BIOSENSOR - An optical element for resonating and reflecting incident light having a wavelength includes a periodic structure formed of protrusions and recessions. A period of the periodic structure is equal to or less than the wavelength of the incident light. The incident light having the wavelength is resonated and reflected by a resonance caused between the incident light and the protrusions and recessions. Widths of the protrusions are spatially changed.01-21-2010
20100054110REFLECTING WAVELENGTH PLATE AND OPTICAL PICKUP USING REFLECTING WAVELENGTH PLATE - Disclosed is a reflecting wavelength plate that deflects and reflects a light path and adds a phase difference with respect to plural incident light having different wavelengths. The reflecting wavelength plate includes a substrate; a reflecting film laminated on the substrate; and a sub-wavelength concavo-convex structure that is laminated on the reflecting film and has a pitch less than or equal to the shortest wavelength of the plural incident light. The filling factor and the groove depth of the sub-wavelength concavo-convex structure are determined so as to add the phase difference obtained by (kπ)/8, where k is an integer, to the plural incident light having the different wavelengths.03-04-2010
20100118366POLARIZATION SPLITTING DEVICE, METHOD OF MANUFACTURING POLARIZATION BEAM SPLITTER, OPTICAL SCANNING DEVICE, AND IMAGE FORMING APPARATUS - A polarization splitting device includes a polarization beam splitter having a polarization splitting surface and allows P-polarized light to transmit therethrough and reflects S-polarized light. A subwavelength structure grating is formed on the polarization splitting surface with a grating pitch smaller than wavelength of incident light. The polarization splitting device also includes a polarizer that is arranged on an optical path of light reflected from the polarization beam splitter and has a transmission axis that is parallel to a polarization direction of the S-polarized light.05-13-2010
20100135130OPTICAL PICKUP AND OPTICAL INFORMATION PROCESSING DEVICE - A disclosed optical pickup includes an aberration correction unit with a phase shifter surface. On the phase shifter surface, rectangular or staircase-like steps are formed in a concentric manner around an optical axial center, in certain regions where a light beam passes through. The steps have different heights in the optical axial direction. A light beam having a wavelength of 405 nm is directly transmitted through the steps so that a phase difference is applied for correcting spherical aberration that occurs on a first optical recording medium. A light beam that passes through an annular region without any steps is focused on a second optical recording medium. A light beam that passes through an outside region is focused by an object lens on the second optical recording medium, and is not focused on the first optical recording medium.06-03-2010
20100155977OPTICAL DEVICE, METHOD OF PRODUCING THE SAME, OPTICAL PICKUP, AND OPTICAL INFORMATION PROCESSING DEVICE - An optical device having a sub-wavelength grating formed in a specified region is disclosed that is able to prevent wave front degradation accompanying a phase difference of a polarized light beam passing through the optical device. The optical device includes a circular-belt-like region where the sub-wavelength diffraction grating is formed, and a center portion where the sub-wavelength diffraction grating is not formed. A vertically polarized light beam used for operations on a blue-light optical recording medium A has a phase difference in the sub-wavelength diffraction grating to be an integral multiple of 2π and hence is transmitted through the sub-wavelength diffraction grating. A horizontally polarized light beam used for operations on a blue-light optical recording medium is diffracted by the sub-wavelength diffraction grating. The light path length L06-24-2010
20100208060LIQUID DROPLET RECOGNITION APPARATUS, RAINDROP RECOGNITION APPARATUS, AND ON-VEHICLE MONITORING APPARATUS - Disclosed is a liquid droplet recognition apparatus for detecting liquid droplets attached to a front surface of a transparent member. The apparatus includes an image pickup apparatus that picks up a vertically polarized light image and a horizontally polarized light image at the front surface of the transparent member from a side of a rear surface of the transparent member; and a signal processing unit that determines whether the liquid droplets are attached to the front surface of the transparent member based on a polarized-light image ratio composed of the vertically polarized light image and the horizontally polarized light image picked up by the image pickup apparatus.08-19-2010
20100278029REFLECTING WAVELENGTH PLATE AND OPTICAL PICKUP USING REFLECTING WAVELENGTH PLATE - Disclosed is a reflecting wavelength plate that deflects and reflects a light path and adds a phase difference with respect to plural incident light having different wavelengths. The reflecting wavelength plate includes a substrate; a reflecting film laminated on the substrate; and a sub-wavelength concavo-convex structure that is laminated on the reflecting film and has a pitch less than or equal to the shortest wavelength of the plural incident light. The filling factor and the groove depth of the sub-wavelength concavo-convex structure are determined so as to add the phase difference obtained by (kπ)/8, where k is an integer, to the plural incident light having the different wavelengths.11-04-2010
20110002215OPTICAL PICKUP DEVICE AND OPTICAL INFORMATION PROCESSING APPARATUS USING THE OPTICAL PICKUP DEVICE - An optical pickup device is disclosed. In the optical pickup device, S-polarized light is input to a polarization filter from a DVD light source or a CD light source. Since the polarization filter transmits through the S-polarized light and diffracts P-polarized light, the S-polarized light is transmitted through the polarization filter. The S-polarized light is converted into three beams by being diffracted by a diffraction element. The three beams reflected at a polarization beam splitter are converted into circularly polarized light by a ¼ wavelength plate via a collimate lens, and the circularly polarized light is condensed on an optical recording medium via an objective lens. Light reflected from the optical recording medium is converted into linear P-polarized light by the 01-06-2011

Patent applications by Hideaki Hirai, Kanagawa JP