Polarized Or Polarizing Patents (Class 369/112.16)
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Patent number: 7081613Abstract: A retroreflective photoelectric sensor has a light-emitting optical system having a light-emitting element and a first polarizer and serving to transmit light from the light-emitting element through the first polarizer, a light-receiving optical system having a second polarizer and a light-receiving element and serving to convert light received through the second polarizer into an electrical signal by the light-receiving element, the first and second polarizers having mutually perpendicular polarizer axes, a single lens for both emitting light from the light-emitting element and receiving light to the light-receiving element therethrough, a beam splitter serving to direct light received from the light-emitting optical system to the single lens and light received from the single lens to the light-receiving optical system, and a phase shifter inserted between the light-emitting optical system and the single lens.Type: GrantFiled: March 16, 2006Date of Patent: July 25, 2006Assignee: OMRON CorporationInventors: Yoshikazu Majima, Yukinori Kurumado, Arata Nakamura
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Patent number: 7046614Abstract: In an optical pickup projecting a laser beam from a laser diode onto a disk through a half mirror, a collimator lens and an objective lens and receiving the laser beam reflected by the disk in a photodiode through the half mirror thereby reading information recorded in the disk, a portion of a metal board body having a pattern of a printed board corresponding to a connector pin fed with a high-frequency signal is notched to cause no electrostatic capacitance between the metal board body and the printed board thereby preventing a read signal from the photodiode from a jitter. Thus obtained is a high-performance and low-priced optical pickup causing no reading error.Type: GrantFiled: January 22, 2003Date of Patent: May 16, 2006Assignee: Funai Electric Co., Ltd.Inventor: Mio Koga
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Patent number: 7045766Abstract: A retroreflective photoelectric sensor may be of a biaxial type or of a coaxial type. A sensor of the biaxial type includes a light-emitting optical system having a light-emitting element, a first polarizer and a light-emitting lens arranged sequentially in this order, a light-receiving optical system having a light-receiving lens, a second polarizer and a light-receiving element arranged sequentially in this order, and a phase shifter inserted between the first polarizer and the light-emitting lens of the light-emitting optical system. The polarizer axes of the first and second polarizers are mutually perpendicular. A phase shifter such as a ½ wave plate may further be placed between the first polarizer and the light-emitting lens of the light-emitting optical system.Type: GrantFiled: December 8, 2003Date of Patent: May 16, 2006Assignee: OMRON CorporationInventors: Yoshikazu Majima, Yukinori Kurumado, Arata Nakamura
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Patent number: 7016290Abstract: In an optical information medium comprising an information recording layer having a mark train of marks and spaces, the mark train is read out by scanning it with a laser beam and detecting a light intensity change pattern of reflected laser beam. Provided that the reflected laser beam includes polarized light components which define an angle ? with the mark train, a polarized light component giving ?=0 is x0 component, and a polarized light component giving ?=90° is y0 component, the mark train is read out utilizing at least a light intensity change of x0 component. When pits or recorded marks having a size approximate to or below the resolution limit are read out, the present invention allows high read outputs to be obtained and prevents omission of readout signals.Type: GrantFiled: October 15, 2002Date of Patent: March 21, 2006Assignees: TDK Corporation, National Institute of Advanced Industrial Science and TechnologyInventors: Takashi Nakano, Hisako Fukuda, Junji Tominaga, Nobufumi Atoda, Takashi Kikukawa
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Patent number: 7009929Abstract: The optical pickup reads an information signal by emitting a light beam to an information recording surface of a recording medium having a recording track composed of information pits arranged for recording the information signal. The optical pickup is provided with: a light source which emits the light beam having linear polarization; an optical system which guides the emitted light beam to the information recording surface and further guides light that is emitted from the information recording surface based on the guided light beam, to an optical path different from an optical path to the light source; and a light-receiving device which receives the light guided by the optical system from the information recording surface. The optical system controls a polarization direction of the emitted light beam, with respect to a direction of the recording track.Type: GrantFiled: February 23, 2004Date of Patent: March 7, 2006Assignee: Pioneer CorporationInventor: Takehiro Motegi
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Patent number: 6980505Abstract: In an optical head apparatus including a first light source for emitting a first light beam having a first wavelength, a second light source for emitting a second light beam having a second wavelength different from the first wavelength, an objective lens, a photodetector, and first and second optical combining/splitting elements, the first optical combining/splitting element receives the first light beam from the first light source to outgo most of the first light beam therefrom to the second optical combining/splitting element and receives the first and second light beams from the second optical combining/splitting element to outgo most of the first and second light beams therefrom to the photodetector.Type: GrantFiled: September 16, 2002Date of Patent: December 27, 2005Assignee: NEC CorporationInventors: Ryuichi Katayama, Eiichi Ueda, Taku Tsuboi
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Patent number: 6956192Abstract: A DVD laser emits a first light beam, and a CD laser emits a second light beam. An optical diffraction element diffracts first and second reflected lights corresponding to the first and second light beams, respectively. An optical detection element detects the first and second reflected lights reflected from a polarizing beam splitter. The optical axes of the CD and DVD lasers are set to diverge from each other. Thus, reflected light components necessary for focusing and tracking of a CD and a DVD are all detected by a detection element.Type: GrantFiled: September 2, 2004Date of Patent: October 18, 2005Assignee: Kabushiki Kaisha ToshibaInventor: Sou Ishika
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Patent number: 6940801Abstract: An optical recording medium, an optical recording and reproducing method, and an apparatus that can record and reproduce multilevel information at a high density and with a high S/N ratio. Recording light emitted from a light source is collimated by a collimation lens and introduced into a polarization rotary device. Recording light transmitted by the polarization rotary device is focused by an objective lens onto an optical recording medium. In response, a photo-induced birefringence is recorded on the optical recording medium. Multilevel recording is performed by controlling a voltage applied to the polarization rotary device to change a polarization angle ? of recording light. Reproduction is performed by detecting light reflected from the optical recording medium with an analyzer and a detector.Type: GrantFiled: October 29, 1998Date of Patent: September 6, 2005Assignee: Fuji Xerox Co., Ltd.Inventors: Tsutomu Ishii, Katsunori Kawano, Kazuo Baba, Kiichi Ueyanagi
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Patent number: 6930972Abstract: An optical disk device has an aperture of an objective lens in an incoming path of a beam from a semiconductor laser to an optical disk formed larger than an aperture in a return path from the optical disk or an aperture is varied in recording and in reproduction. This configuration improves recording/reproducing ability since light is focused on an optical disk with high numerical aperture. In addition, since reflected light from the optical disk is detected with low numerical aperture, margins for tilt and defocus are not reduced. Furthermore, since unnecessary signal components contained in the reflected light can be eliminated, a S/N (signal-to-noise ratio) of an information signal also increases. Thus, a high-performance optical disk device can be obtained. Alternatively, by varying the aperture of an objective lens in recording and in reproduction, an optical disk device in which recording density and recording quality are increased without deteriorating reproduction quality can be obtained.Type: GrantFiled: July 10, 2003Date of Patent: August 16, 2005Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Youichi Saitoh, Junichi Asada, Yuichi Takahashi, Seiji Nishiwaki, Kenji Nagashima, Kazuo Momoo, Junji Nagaoka
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Patent number: 6917576Abstract: An adhesive is coated on at least one surface of a thin film of organic material having birefringent properties and a phase-difference producing function, and a fixing substrate having transmitting or reflecting properties is bonded to the thin film of organic material by the adhesive, wherein materials satisfying relations of E1<E2 and E3<E2 where E1 is the linear expansion coefficient of the thin film of organic material, E2 is the linear expansion coefficient of the adhesive and E3 is the linear expansion coefficient of the fixing substrate, and the glass transition temperature of the thin film of organic material being 150° or more, are selected.Type: GrantFiled: March 31, 2003Date of Patent: July 12, 2005Assignee: Asahi Glass Company, LimitedInventors: Takehiko Nishiyama, Naomitsu Umemura, Hiromasa Sato, Masahiro Murakawa, Yoshiharu Ooi, Yuzuru Tanabe
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Patent number: 6888786Abstract: An optical device including a light source for emitting diverging light, a polarizing beam splitter for transmitting or reflecting the diverging light according to a polarized light component, a collimator lens for converting the diverging light transmitted through the polarizing beam splitter into collimated light, and an objective lens for focusing the collimated light on an object. The optical device further includes an optical element arranged between the collimator lens and the objective lens for producing a phase difference of +90°±15° or ?90°±15° between P-polarized light and S-polarized light. The optical element has a principal axis perpendicular or parallel to a plane of incidence of the diverging light on the polarizing beam splitter. For example, the optical element is provided by a quarter-wave plate having an optic axis perpendicular or parallel to the plane of incidence of the diverging light on the polarizing beam splitter.Type: GrantFiled: July 21, 2003Date of Patent: May 3, 2005Assignee: Fujitsu LimitedInventors: Nobuhide Aoyama, Shin-ya Hasegawa
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Patent number: 6859429Abstract: An aberration correcting unit includes: a first element having a liquid crystal sandwiched between first electrode layers, the first element having a first predetermined orientation direction and providing a light with a phase change by applying a voltage; a second element having a liquid crystal sandwiched between the second electrode layers, the second element having a second predetermined orientation direction that is substantially perpendicular to the first orientation direction and providing a light with a phase change by applying a voltage; and a polarization-direction changing element which is arranged between a light source of the light beam and the first and second elements to change a polarization direction of the light beam.Type: GrantFiled: May 24, 2001Date of Patent: February 22, 2005Assignee: Pioneer CorporationInventors: Masakazu Ogasawara, Masayuki Iwasaki
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Publication number: 20040264350Abstract: A polarizing optical element changes its optical reflectance and/or transmittance according to a polarization state of incoming light. The optical element includes: a first grating layer including multiple striped portions that extend in a predetermined direction; and a second grating layer including multiple striped portions that extend in that predetermined direction. Average grating pitches of the first and second grating layers are both defined to be shorter than the wavelength of the incoming light. The first grating layer is made of a first material that exhibits a light reflecting property to the incoming light. The second grating layer is made of a second material that reduces the reflection of the incoming light from the first grating layer.Type: ApplicationFiled: June 15, 2004Publication date: December 30, 2004Applicant: SHARP KABUSHIKI KAISHAInventors: Shun Ueki, Tokio Taguchi, Satoshi Shibata, Kiyoshi Minoura, Masahiro Shimizu
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Publication number: 20040257961Abstract: The present invention is directed to an optical head adapted for performing recording or reproduction of information signals with respect to an optical disc (102), which controls light coupling efficiency with respect to light beams irradiated onto the optical disc (102) by light coupling efficiency adjustable element such as a liquid crystal element (214), etc. in accordance with type of the optical disc (102), recording surface of multi-layer optical disc and/or operation mode to change power of light beams irradiated onto the optical disc (102) to a large extent without excessively increasing change quantity of output power of a semiconductor laser element (212). A beam splitter (218) divides incident light beams of P-polarized light at a predetermined ratio to allow the light beams thus obtained to be incident on a light detector (219) for disc surface power monitor.Type: ApplicationFiled: April 26, 2004Publication date: December 23, 2004Inventors: Noriaki Nishi, Masaru Tezuka, Kunika Hashimoto
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Publication number: 20040218504Abstract: An optical pickup includes a laser light source, an objective lens which focuses light emitted from the laser light source on an optical information storing medium, an optical path changer which changes a proceeding path of the light emitted from the laser light source, a polarization changer which changes the polarization of an incident light to make the polarization of light reflected by the optical information storing medium and reentering the laser light source different from that of the light emitted from the laser light source, so that noise generated due to interference by the light reflected by the optical information storing medium and reentering the laser light source is reduced, and a photodetector which receives incident light reflected by the optical information storing medium and sequentially passing through the objective lens and the optical path changer and detects an information signal and/or an error signal.Type: ApplicationFiled: November 12, 2003Publication date: November 4, 2004Applicant: Samsung Electronics Co., Ltd.Inventors: Ki-bok Kim, No-jun Kwak, Jong-ryull Kim
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Publication number: 20040218505Abstract: An optical illumination apparatus has a polarization conversion device for converting light from a light source into light polarized uniformly in a predetermined manner and an optical integrator system for illuminating a display panel with the light polarized in the predetermined manner. The polarization conversion device splits the light from the light source into a first light beam and a second light beam in such a way that the first and second light beams are polarized in different manners, and then converts one of the first and second light beams into light polarized in the identical manner as the other light beam. Moreover, the first and second light beams pass through an identical lens cell of a first lens array of the optical integrator system and are imaged on an identical lens cell of a second lens array of the optical integrator system.Type: ApplicationFiled: May 12, 2004Publication date: November 4, 2004Applicant: MINOLTA CO., LTD.Inventor: Kohtaro Hayashi
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Patent number: 6813235Abstract: An optical pickup apparatus has a simplified configuration for using a plurality of laser beams at different wavelength to reduce the size, and a laser diode chip for use therewith. An irradiation light path for leading a laser beam emitted from a light emitter to a recording medium is provided with an optical axis correcting element for passing a first laser beam and for diffracting a second laser beam having a wavelength different from that of the first laser beam to generate diffracted light which has the optical axis substantially matching the optical axis of the first laser beam. The optical axis correcting element is arranged at a position at which the center of a light intensity distribution of the first laser beam incident thereto matches the center of a light intensity distribution of the second laser beam incident thereto.Type: GrantFiled: November 21, 2001Date of Patent: November 2, 2004Assignee: Pioneer CorporationInventors: Hitoshi Furuhata, Tomotaka Nishimura, Nobuo Ishida, Taichi Akiba
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Publication number: 20040213135Abstract: 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.Type: ApplicationFiled: April 19, 2004Publication date: October 28, 2004Applicant: Konica Minolta Opto, Inc.Inventors: Nobuyoshi Mori, Tohru Kimura
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Publication number: 20040202089Abstract: An optical pick-up device includes a light source (2), a polarized light beam converter (4), a splitter (6), a collimating lens (7), and a photo-detector (9). A linear polarized light beam with a first type of polarized component and a second type of polarized component is emitted from the light source, and passes through the polarized light beam converter. The first type of polarized component is converted into the second type of polarized component by the polarized light beam converter. Then part of the light beam with the second type of polarized component passes through the splitter and is focused onto an optical disc (8) by the collimating lens. The optical disc reflects the light beam that contains recorded information read from the optical disc. The reflected light beam passes back through the collimating lens, is reflected by the splitter, and is received by the photo-detector.Type: ApplicationFiled: April 9, 2004Publication date: October 14, 2004Inventor: Jyh-Chain Lin
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Publication number: 20040202088Abstract: A polarizing optical element is used in an optical pickup apparatus. A diffraction grating (hologram) is formed on the polarizing optical element. The diffraction efficiency of the diffraction grating varies in accordance with the polarization direction of an incident optical beam. When the duty ratio of the diffraction grating is defined as the ratio of the width of a protrusion of the diffraction grating to the grating period, the duty ratio of the diffraction grating is within the range of 0.4-0.5.Type: ApplicationFiled: December 23, 2003Publication date: October 14, 2004Inventor: Shigeru Oohchida
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Patent number: 6804185Abstract: A variable optical unit is provided with at least two phase-shift regions for providing light with phase differences. Phase-shift amount of the phase-shift region is adjusted by the applied voltage in accordance with birefringence of an information medium. A light beam emitted from a light source is incident on the variable optical unit through a collimator lens and a beam splitter. The light beam is polarized in accordance with the aforementioned phase-shift amount of the variable optical unit and converged by an objective lens to radiate the information medium. The reflected light polarized due to the effect of the birefringence of the information medium is polarized again according to the phase-shift amount of the variable optical unit. The reflected light is thereby polarized in the direction in which the beam splitter can reflect the reflected light and then the reflected light reflected by the beam splitter is detected by the condenser lens and an optical detector.Type: GrantFiled: December 18, 2000Date of Patent: October 12, 2004Assignee: Pioneer CorporationInventors: Ikuya Kikuchi, Takanori Maeda, Mitsuru Sato, Masayuki Iwasaki
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Publication number: 20040165519Abstract: The optical pickup reads an information signal by emitting a light beam to an information recording surface of a recording medium having a recording track composed of information pits arranged for recording the information signal. The optical pickup is provided with: a light source which emits the light beam having linear polarization; an optical system which guides the emitted light beam to the information recording surface and further guides light that is emitted from the information recording surface based on the guided light beam, to an optical path different from an optical path to the light source; and a light-receiving device which receives the light guided by the optical system from the information recording surface. The optical system controls a polarization direction of the emitted light beam, with respect to a direction of the recording track.Type: ApplicationFiled: February 23, 2004Publication date: August 26, 2004Applicant: PIONEER CORPORATIONInventor: Takehiro Motegi
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Patent number: 6775221Abstract: An optical pickup provided with a semiconductor laser for outputting a linear polarized laser beam, an objective lens for condensing a laser beam from the semiconductor laser and supplying the same to a track of an optical disk with lands and/or grooves formed therein, a polarization plate supplied with the laser beam reflected at the optical disk via the objective lens and a beam splitter, and changing an overlapping region in which a 0-th order diffraction light and a 1st order diffraction light contained in the supplied laser beam overlap and a nonoverlapping region to linear polarized light orthogonal or substantially orthogonal to each other, and a photo detector supplied with the laser beam passed through the polarization plate via a focus lens and a cylindrical lens.Type: GrantFiled: October 24, 2000Date of Patent: August 10, 2004Assignee: Sony CorporationInventor: Atsushi Fukumoto
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Publication number: 20040120245Abstract: An optical head for reproducing information contained on an optical information disk includes a plurality of light sources and a plurality of light receiving elements in correspondence with the plurality of laser light sources. There is constructed a constitution in which one laser light source in the plurality of laser light sources is constituted by an individual laser diode and which includes a laser module constituted by other laser light sources and the plurality of light receiving elements to thereby enable to realize the small size of the optical head.Type: ApplicationFiled: December 8, 2003Publication date: June 24, 2004Applicant: Hitachi, Ltd.Inventors: Kouji Arikawa, Shigeru Nakamura, Kazuo Shigematsu
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Publication number: 20040114496Abstract: An optical pickup has a support pedestal integrally formed at a rear end portion of a mounting surface of a base. A pair of left and right leg portions extend forwardly from both side edge portions of a rear end portion of a resilient plate. A fixing hole is penetratingly provided in each of the leg portions on a phantom line passing through a central axis of a photodiode and extending in a horizontal transverse direction. Each fixing screw is screwed into a threaded hole in the mounting surface through each fixing hole, so as to press the rear end portion of the resilient plate against the support pedestal.Type: ApplicationFiled: September 9, 2003Publication date: June 17, 2004Applicant: FUNAI ELECTRIC CO., LTD.Inventors: Teruaki Sogawa, Fumiaki Mori, Noritaka Tanabe
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Patent number: 6741528Abstract: P-polarized parallel rays are irradiated on a magneto-optical disk 1 and reflected. The reflected light is reflected by a first beam splitter 14 and supplied to a reproduced signal detection system 20. This reflected light is supplied to a light shading plate 21, and a p-polarized component is transmitted at a transmittance of substantially 100% and an s-polarized component is transmitted at a transmittance of substantially 0%, i.e., reflected or absorbed so as to be shaded, in the area of a polarization film 21b. The light transmitted through the light shading plate 21 incides on a polarization beam splitter 19 where it is split into the p-polarized component and s-polarized component, and a reproduced signal is detected by differential detection.Type: GrantFiled: July 21, 2000Date of Patent: May 25, 2004Assignee: Fujitsu LimitedInventor: Haruhiko Izumi
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Publication number: 20040095869Abstract: The present invention provides an optical pickup device comprises at least:Type: ApplicationFiled: October 29, 2003Publication date: May 20, 2004Applicant: SHARP KABUSHIKI KAISHAInventor: Akiho Yoshizawa
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Patent number: 6721258Abstract: The present invention is directed to the provision of an optical device that can easily eliminate only side lobes or side lobe components from a super-resolution optical spot.Type: GrantFiled: December 20, 2001Date of Patent: April 13, 2004Assignee: Citizen Watch Co., Ltd.Inventor: Nobuyuki Hashimoto
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Patent number: 6714495Abstract: A pickup device and an information recording/reproducing apparatus for reproducing information in which crosstalks have been suppressed without causing an erasure or the like of the information which has already been recorded on an information recording medium. The apparatus has a light source 1 for emitting first and second lights whose polarizing directions cross perpendicularly. The first and second lights are transmitted through a grating for merely transmitting the first light and diffracting the second light at a predetermined diffraction efficiency and those lights are converged by an objective lens, thereby forming a laser beam and irradiating it onto an optical disc. At the time of the recording of information, the second light is set to a light-off mode or a low power state and the recording of information is performed by the laser beam caused by the first light.Type: GrantFiled: December 18, 2000Date of Patent: March 30, 2004Assignee: Pioneer CorporationInventor: Takanori Maeda
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Patent number: 6700854Abstract: There is disclosed a storage apparatus which is of a system of utilizing a polarized state change by Kerr effect to read information from a storage medium and which easily and precisely performs adjustment to compensate for a phase deviation between both P, S polarized components attributed to an optical system. Phase plates 500, 510 are disposed between a fixed optical section 200 and a movable optical section 190 and the inclination angles of the phase plates are adjusted.Type: GrantFiled: April 17, 2000Date of Patent: March 2, 2004Assignee: Fujitsu LimitedInventors: Kazuyuki Mizuishi, Masahiko Kataoka, Hidenori Saito
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Publication number: 20040032804Abstract: A method of arranging an optical pickup system on a deck of an optical recording and/or reproducing apparatus, which enables detection of a tracking error signal using one photodetector based on a three-beam method and by a differential phase detection method. The optical pickup system includes a light source, a diffractive optical element which diffracts a light beam incident from the light source and splits the same into at least three beams, a plate-type beam splitter which changes a propagation path of the light beam, and a photodetector including at least one main photodetector having at least four sections and a plurality of sub-photodetectors. The optical pickup system is constructed so as to have a reflecting mirror redirect the propagation path of the light beam emitted from the light source toward a recording medium.Type: ApplicationFiled: June 13, 2003Publication date: February 19, 2004Applicant: SAMSUNG ELECTRONICS CO., LTD.Inventors: Bong-gi Kim, Chun-seong Park, Soo-han Park, Moon-whan Lee, Hyo-chan Lee, Jong-uk Kim, Seong-su Park, Tae-youn Heor, Do-hoan Nam
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Publication number: 20030235127Abstract: An optical pickup to focus a light emitted from a light source using an objective lens, forming a light spot on a recording surface of a recording medium, and performing recording and/or reproducing operations using the light. The optical pickup includes a monitor photodetector and an optical element installed in front of the monitor photodetector to receive and to detect a portion of the light emitted from the light source to control an amount of light power output from the light source and to adjust at least one of an intensity, a beam profile, and a proceeding direction of the light incident on the monitor photodetector.Type: ApplicationFiled: June 19, 2003Publication date: December 25, 2003Applicant: SAMSUNG ELECTRONICS CO., LTDInventors: Dong-Ryeol Lee, Yong-Jun Cho, Pyong-Yong Seong, Young-Kug Yoon, Kun-Soo Kim, Sun-Mook Park
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Publication number: 20030223345Abstract: An optical disk apparatus includes a light source for emitting light in a prescribed wavelength range, an objective lens system for causing the light emitted from the light source to be focused onto a storage disk, and a reproduction signal system for causing return light from the storage disk to be conduced to a detector. The light emitted from the light source has a direction of polarization parallel to a recoding track of the storage disk. The objective lens system has transmission factors for s-polarized light and p-polarized light that are defined relative to the objective lens system. The transmission factor for s-polarized light is greater than the transmission factor for p-polarized light.Type: ApplicationFiled: November 13, 2002Publication date: December 4, 2003Applicant: FUJITSU LIMITEDInventors: Kazushi Uno, Koichi Tezuka
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Patent number: 6639888Abstract: The present invention relates to an information reading and recording device for reading and recording information of an optical signal. The optical system in this information reading and recording device is simplified by using a diffraction optical system. In an information reading and recording device, in which an optical disk is used, including a light source of a semiconductor laser and an image formation lens for condensing beams of light sent from the semiconductor laser so as to form an image on an optical disk medium, a diffraction optical element, the diffraction efficiency of which depends upon a direction of polarization of light, is arranged between the semiconductor lens and the image formation lens, and diffraction light of the diffraction optical element is introduced into a servo detecting optical system.Type: GrantFiled: October 27, 1998Date of Patent: October 28, 2003Assignee: Fujitsu LimitedInventor: Shinya Hasegawa
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Patent number: 6633530Abstract: An optical pickup apparatus has a light source unit that includes a first light source and a common light-receiving device having first and second light-receiving sections. The optical pickup apparatus further includes an optical path composition element that guides first light emitted from the first light source and second light emitted from another light source into an optical path that passes an objective lens, and an optical path polarization element that guides reflected lights of the first and the second lights to the common light-receiving device. The optical path polarization element is mounted in the light source unit for guiding reflected lights of the first and second lights to the common light-receiving device.Type: GrantFiled: August 30, 2000Date of Patent: October 14, 2003Assignee: Sankyo Seiki Mfg. Co., Ltd.Inventor: Tadashi Takeda
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Patent number: 6625102Abstract: The present invention provides an optical device that eliminates side lobes or their components from a super-resolution optical spot, and that is capable of electrically switching between super resolution and normal resolution as needed in simple manner. The optical device having a light generating unit for generating incident light and a lens system for collecting the incident light and producing a super-resolution optical spot containing a main lobe and a side lobe by modulating a portion of the incident light, comprises a polarization vector modulation unit for making polarization vectors of the side lobe and the main lobe differ from each other so that one or the other of the polarization vectors can be selected, and a polarization selective unit for eliminating the side lobe by selecting the polarization vector of the main lobe.Type: GrantFiled: August 9, 2001Date of Patent: September 23, 2003Assignee: Citizen Watch Co., Ltd.Inventor: Nobuyuki Hashimoto
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Publication number: 20030165108Abstract: In an optical pickup device, reliability of a holding structure for an optical component (a half mirror) with respect to a pair of mounting frames is intended to be enhanced. A half mirror (5) is arranged so as to bridge a first frame (11) and a second frame (12). A side face (5C) positioned in a part in which one side of an emitting face (5B) (a mounting face) of this half mirror 5 and the first frame (11) are overlapped is fixed to the first frame (11) by adhesives (13A) of two contact points. On the other hand, a side face (SD) positioned in a part in which the other side of the emitting face (5B) and the second frame (12) are overlapped is fixed to the second frame (12) by an adhesive (13B) of one contact point. In this manner, even in case where the frames (11, 12) have been displaced due to thermal expansion, the adhesives (13A, 13B) will not be flaked off, and bonding strength of the half mirror will be enhanced.Type: ApplicationFiled: March 1, 2002Publication date: September 4, 2003Applicant: Yamaha CorporationInventor: Shin Ito
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Publication number: 20030156526Abstract: In an optical pickup projecting a laser beam from a laser diode onto a disk through a half mirror, a collimator lens and an objective lens and receiving the laser beam reflected by the disk in a photodiode through the half mirror thereby reading information recorded in the disk, a portion of a metal board body having a pattern of a printed board corresponding to a connector pin fed with a high-frequency signal is notched to cause no electrostatic capacitance between the metal board body and the printed board thereby preventing a read signal from the photodiode from a jitter. Thus obtained is a high-performance and low-priced optical pickup causing no reading error.Type: ApplicationFiled: January 22, 2003Publication date: August 21, 2003Inventor: Mio Koga
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Publication number: 20030117917Abstract: An optical pickup for performing data recording and reproduction with respect to both CDs and DVDs and a disk apparatus incorporating the optical pickup. The optical pickup comprises a CD laser diode and a DVD laser diode, and creates a composite CD/DVD laser beam using a composite prism. An optical film is formed on a composite plane of the composite prism to reduce concentration of the DVD laser beam in its central portion relative to that in its peripheral portion to thereby obtain characteristics of concentration distribution which is flatter than that of Gaussian distribution. For a composite prism of a type which transmits a CD laser beam and reflects a DVD laser beam, the optical film is adjusted such that a reflection rate of a DVD laser beam is minimized for a DVD laser beam incoming at an optical axis incident angle.Type: ApplicationFiled: December 24, 2002Publication date: June 26, 2003Applicant: TEAC CorporationInventor: Hiroyuki Shindo
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Patent number: 6580674Abstract: An adhesive is coated on at least one surface of a thin film of organic material having birefringent properties and a phase-difference producing function, and a fixing substrate having transmitting or reflecting properties is bonded to the thin film of organic material by the adhesive, wherein materials satisfying relations of E1<E2 and E3<E2 where E1 is the linear expansion coefficient of the thin film of organic material, E2 is the linear expansion coefficient of the adhesive and E3 is the linear expansion coefficient of the fixing substrate, and the glass transition temperature of the thin film of organic material being 150° or more, are selected.Type: GrantFiled: May 22, 2001Date of Patent: June 17, 2003Assignee: Asahi Glass Company, LimitedInventors: Takehiko Nishiyama, Naomitsu Umemura, Hiromasa Sato, Masahiro Murakawa, Yoshiharu Ooi, Yuzuru Tanabe
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Patent number: 6556532Abstract: There can be obtained a miniaturized, 3-beam optical pickup device using a polarization separating prism of an inexpensive material and capable of reliably detecting light of a signal. The present pickup device includes an optical element having the first, second and third members, and having a first boundary surface receiving light from a semiconductor laser and reflecting and directing it toward a collimator lens, and also transmitting light reflected by an MO disc and directing it toward a photodetector, and a second boundary surface separating polarized light of light transmitted through the first boundary surface.Type: GrantFiled: June 6, 2001Date of Patent: April 29, 2003Assignee: Sharp Kabushiki KaishaInventors: Masaru Ogawa, Tetsuo Saeki
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Patent number: 6552317Abstract: A phase difference plate (12) converts states of polarization of emergent light form a laser light source (13) and return light form an optical recording medium (5). A diffractive element (21) separates the return light from an optical axis leading from the laser light source (13) to the optical recording medium (5), and guides the return light to a photodetector (14) on the basis of a difference between the states of polarization of the emergent light and the return light. The polarization direction of emergent light from the laser light source (13) is arranged so as to be oriented in the radial direction of the optical recording medium (5) (in the direction of birefringence of the optical recording medium).Type: GrantFiled: June 13, 2000Date of Patent: April 22, 2003Assignee: Kabushiki Kaisha Sankyo Seiki SeisakushoInventors: Tadashi Takeda, Yuichi Takei, Yoshio Hayashi
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Patent number: 6542298Abstract: The invention provides a cutting step of a polarization beam separating material less susceptible to cutting position slipping. In particular, the present invention relates to a method for manufacturing a polarization beam splitter for splitting an incident beam into two types of linearly polarized beams. A laminate is constructed by gluing a plurality of substrates, at least some of which have a polarization beam separating film on one surface thereof. The planar laminate of the substrate is cut at a predetermined angle to the surface thereof to form a generally planar polarization beam splitter block in which a plurality of prisms are glued, each having a parallelogrammatic shape in cross section. A rectangular parallelepiped polarization beam splitter is thus formed by cutting away a prism portion having a generally trapezoidal shape in cross section from at least one end portion of the polarization beam splitter block.Type: GrantFiled: June 16, 2000Date of Patent: April 1, 2003Assignee: Seiko Epson CorporationInventor: Kazuo Aoki
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Patent number: 6512733Abstract: The present invention provides an optical recording method, optical recording apparatus, optical reading method, and optical reading apparatus which are capable of high density recording an d high speed recording, and high speed reading. In recording, a recording light comprising a plurality of polarization distributions corresponding to the data information; is generated, and irradiated onto an optical recording medium to thereby record a plurality of polarization distributions of the recording light on the optical recording medium as photo-induced birefringence. In reading, a reading light having a uniform polarization distribution is irradiated onto the recording medium in which the data information has been recorded previously, and the polarization distribution of the transmitted light or reflected light in the optical recording medium is read as the polarization distribution of the reproducing light.Type: GrantFiled: August 30, 1999Date of Patent: January 28, 2003Assignee: Fuji Xerox Co., Ltd.Inventors: Katsunori Kawano, Tsutomu Ishii, Kazuo Baba
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Patent number: 6452890Abstract: An optical storage medium of the present invention enables storage of data with high precision at high speed, and rewriting of data at high speed without an erasing process. Optical storage, reading and retrieving methods and optical storage, reading, and retrieving apparatuses using the medium are also provided. The optical storage medium has at least a polarization-sensitive member having the photo-induced birefringence property, such as a member made of polyester polymer having cyanoazobenzene as a side chain. The above apparatuses have spatial light modulator capable of modulating polarization. The modulator provides information of bit of two-dimensional data to each corresponding pixel by application or non-application of a voltage, and modulates the polarization of the beam incident on each pixel. Thereby, a signal beam transmitted through the spatial light modulator having a spatial polarization modulation corresponding to the two-dimensional data is obtained.Type: GrantFiled: April 8, 1998Date of Patent: September 17, 2002Assignee: Fuji Xerox Co., LTDInventors: Katsunori Kawano, Yasunari Nishikata, Tsutomu Ishii
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Patent number: 6385158Abstract: An optical pickup device for an AS-MO disk, a DVD and a CD includes a dual wavelength semiconductor laser with first and second oscillation devices, a polarization plane rotary unit selectively rotating a plane of polarization of a laser beam 90°, and a polarization selective diffraction grating passing a laser beam straight forward or dividing a laser beam into three beams depending upon the direction of polarization. The optical pickup device operates by the DPP tracking system where three laser beams are directed for an AS-MO disk, and by the DPD tracking system where a single laser beam is directed for a DVD or a CD. As a result, a signal can be reproduced from an AS-MO disk, a DVD, or a CD having different tracking systems.Type: GrantFiled: October 9, 1998Date of Patent: May 7, 2002Assignee: Sanyo Electric Co., Ltd.Inventors: Naoyuki Takagi, Satoshi Sumi
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Patent number: 6369377Abstract: The present invention discloses a multiple-beam holographic optical pick-up head, which has the advantages of the multiple-beam optical pick-up head and the holographic optical pick-up head and can increase the light usage efficiency. This invention uses the property that a polarized diffractive optical element can generate different optical effects for laser beam with different polarizations and places a polarized multiple-beam grating and polarized hologram on the optical path for splitting the incident light toward the disc into multiple reading beams by the multiple-beam grating. The returning laser beams reflected from the disc are diffracted and diverted by the hologram to reach a photodetector. Both the incident and reflective beams are diffracted once only; thus the light usage efficiency can be increased.Type: GrantFiled: July 13, 2000Date of Patent: April 9, 2002Assignee: Industrial Technology Research InstituteInventors: Hsi-Fu Shih, Jau-Jiu Ju, Tzu-Ping Yang, Wei-Chih Lu, Mark O. Freeman, Der-Ray Huang, Carl Y. Yang
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Publication number: 20010050895Abstract: An optical path difference compensation means of a birefringence material: Which transmits incident lights having different wavelength and compensates a phase of the incident light to decrease aberration of one of said incident lights without affecting the other incident light.Type: ApplicationFiled: June 12, 2001Publication date: December 13, 2001Inventor: Man-Hyung Lee
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Patent number: 6327237Abstract: A light source is provided for emitting a first beam having a far-field pattern of an elliptic shape. The first beam is a linearly polarized light having a first polarizing direction in a major axis of the elliptic shape. A half-wave plate is provided for rotating the polarizing direction of the first beam 90 degrees, thereby changing the first beam to a second beam. A beam splitter is provided for changing the elliptic shape of the second beam into a circular shape. The beam splitter is arranged to transmit the second beam and to reflect a third beam having a polarizing direction different from that of the second beam by 90 degrees. A quarter-wave plate is provided for transmitting the second beam from the beam splitter to apply it to an optical disc, and for changing the second beam reflected from the optical disc into the third beam. The third beam reflected from the beam splitter is applied to a photodetector.Type: GrantFiled: May 15, 2001Date of Patent: December 4, 2001Assignee: Pioneer Electronic CorporationInventors: Naoharu Yanagawa, Eiji Muramatsu
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Publication number: 20010028620Abstract: Storage density in an optical data storage media and system is increased many times the resolution limit by fully utilizing the much smaller detection limit by differentiating and isolating the active data sites in the media optically. The tracks are preordained and predisposed to a specific optical property and value that is different from that of its “n” nearest neighbors but is identical to its nth neighbor and to the optical properties of the reading and writing optical system.Type: ApplicationFiled: April 25, 2001Publication date: October 11, 2001Inventor: John M. Guerra