Abstract: An optical pickup apparatus comprising: a laser light source; an objective lens; a reflection mirror; a photodetector; and a beam splitter, the beam splitter including a first reflective film configured to generate a first phase difference corresponding to a predetermined wavelength with respect to laser light, the reflection mirror including a second reflective film configured to generate a second phase difference corresponding to the predetermined wavelength with respect to the laser light, the first reflective film and the second reflective film being formed so that a combined phase difference of the first phase difference and the second phase difference becomes substantially quarter-wave with respect to the laser light.

Abstract: According to one embodiment, an information recording medium has a plurality of recording layers, and records and reproduces information by using a semiconductor layer of 450 nm or less. When reproducing information, letting x be the frequency of repetitive recording of a shortest mark length and shortest space length of the information, the ratio of the value of a highest level to the value of a level at x/190 of a sum signal detected within the frequency range of x/3240 to x/190 is lower than 32 dB, or the ratio of the average value of the amplitudes of signals of repetitive recording of the shortest mark length and shortest space length to the value of the highest level within the frequency range of x/3240 to x/190 is higher than 10 dB.

Abstract: The present techniques provide methods and systems reading a data bit of interest on an optical data disc with a reduced error rate. The data bit estimation may be improved by reducing deterministic noise resulting from an optical reader system and/or the optical data disc. The reader may adjust the position of a detector to detect light scattered from the disc based on parameters of known noise sources. In one embodiment, the detector may be moved vertically in relation to the data bit of interest on the optical disc. In another embodiment, more than one detector may be used to detect light scattered from a data bit of interest. In embodiments, the positioning of the detector(s) may be based on system or disc parameters, and the detected scatterings may provide a data reading, improved for an optical return from a present micro-hologram.

Abstract: According to one embodiment, an information processing apparatus includes an optical disc drive, a measuring module in the optical disc drive, and a measurement value reception module. The measuring module is configured to measure a value related to an operation of a predetermined motor in the optical disc drive, which is executed during a time period of power-up of the optical disc drive. The measurement value reception module is configured to receive a measurement value related to the operation of the predetermined motor from the optical disc drive in response to an event of being requested to turn off the power of the optical disc drive, and to store the received measurement value in a storage device.

Abstract: An object of the invention is to provide an optical disc device, an optical head, and an information processing device that enable to advantageously record or reproduce information with respect to an information recording medium having three or more information recording surfaces with light transmissive layers of different thicknesses from each other.

Abstract: An object of the invention is to prevent damage or performance degradation of an optical component constituting a second optical system, and suppress degradation of the recording/reproducing performance of an optical pickup device. A first laser light source 1 emits a first light beam having a first wavelength. A first optical system 17 guides the first light beam to be emitted from the first laser light source 1 to a first optical disc. A DVD integration unit 11 emits a second light beam having a second wavelength different from the first wavelength. A second optical system 18 guides the second light beam to be emitted from the DVD integration unit 11 to a second optical disc different from the first optical disc in recording density.

Abstract: The present techniques provide systems and methods for decoding a data signal with a control bit to improve bit estimation. The techniques in one embodiment involve using decoding algorithms to estimate the a posteriori state probabilities and the a posteriori transition probabilities of the data encoding, and estimating bit state probabilities. The techniques further involve using a control bit in the bit stream and comparing the estimation of the control bit state in the segment of the bit stream with a test control bit determined based on an average of bit states from the encoded segment of the bit stream. If the estimation of the control bit and the test control bit are not equal, the state of the bit estimate with the lowest confidence probability will be changed.

Abstract: Provided are a method and apparatus for adjusting brightness of an illumination device that is used in photographing an analysis object in a bio disk. The method includes taking images of an analysis object in a bio disk; calculating brightness of the images of the analyzing object; and adjusting brightness of an illumination device which is used in the photographing operation of the analysis object in the bio disk based on a difference between the calculated brightness and a target brightness.

Abstract: An image forming apparatus is provided. An exposure component is equipped with a plurality of light emitting elements arrayed along a first direction. An output component is equipped with output ends corresponding to each of the light emitting elements and the output component, when correcting an amount of misalignment in the first direction, outputs drive signals of one line corresponding to a line on a most upstream side of drive signals of plural lines from the output ends that have been shifted by a number corresponding to the amount of misalignment in the first direction. A plurality of connecting wires interconnect each of the output ends and each of the light emitting elements. A judging component is connected to each of the connecting wires, and judges whether or not the drive signals are being normally transmitted through the connecting wire that the judging component has selected.

Abstract: A combination type optical disk medium and recording or reproducing method in which the medium include first and second recording layers based on different recoding densities. First and second volume spaces are formed to the first and second recording layers, respectively. Each volume space includes identification information of a head or end of the volume space, and an area for data. One of the volume spaces is recorded with identification information of the other volume space.

Abstract: An optical pickup of this invention includes a first objective lens for a CD or DVD, a second objective lens for a BD, a photodetector, a light source for a CD or DVD, a light source for a BD; a first optical mechanism for guiding first reflected light from the CD or DVD toward the photodetector via the first objective lens, and a second optical mechanism for guiding second reflected light from the BD via the second objective lens and changing the direction of the second reflected light toward the first optical mechanism. After the second reflected light joins a light path of the first reflected light guided by the first optical mechanism, the second reflected light is supplied by the first optical mechanism to the photodetector.

Abstract: The present invention provides a multiwavelength semiconductor laser capable of easily setting reflectance in a predetermined range at different oscillation wavelengths on a main emission edge face side. The multiwavelength semiconductor laser includes a plurality of semiconductor light emission parts of an edge emitting type having different oscillation wavelengths, and a reflection film provided commonly for main emission edge faces of the semiconductor light emission parts. The reflection film includes, in order from the semiconductor light emission parts, a first dielectric film (refractive index n1), a second dielectric film (refractive index n2), and a third dielectric film (refractive index n3), and the refractive indexes n1, n2, and n3 satisfy the relation of n3<n1<n2.

Abstract: An optical disk device includes a DPDTE signal generating section that detects misalignment between a light spot and a mark or a pit, an FE signal generating section, an optical crosstalk correcting section which corrects a signal output by the FE signal generating section using the DPDTE signal generating section, and a focus control section which controls an actuator so that a light beam converges on an information layer. The DPDTE signal generating section detects the misalignment on the basis of phase information obtained from signals received from predetermined light receiving areas. The optical crosstalk correcting section performs a correcting operation of removing a signal component from predetermined receiving areas of a detector which component is used for a DPDTE signal, the signal component being contained in the signals from the predetermined light receiving areas of the detector which signals are used by the FE signal generating section.

Abstract: A method to provide data storage services using one or more holographic data storage media disposed in a holographic data storage system operated by a data storage services provider, wherein the holographic data storage system comprises a light source, a spatial light modulator, and a plurality of holographic data storage media, wherein the method receives information provided by the data storage services customer, allocates a first holographic data storage medium for exclusive storage of information provided by the data storage services customer, defines an outer storage portion of the first allocated holographic data storage medium, and stores the information as one or more holograms encoded in the outer storage portion of the first holographic data storage medium.

Abstract: A recording/reproducing apparatus includes: a light source; a first correction section to correct a position of an objective lens that collects laser light from the light source on a surface of an optical disc based on a focus bias setting value obtained from a focus bias value; a second correction section to correct an aberration of the laser light based on an aberration correction setting value obtained from an aberration correction value; an evaluation value generation section to generate an evaluation value; a focus bias adjustment section to change plus/minus of the focus bias value and calculate a new focus bias value based on the evaluation value every time a first cycle passes; and an aberration adjustment section to change plus/minus of the aberration correction value and calculate a new aberration correction value every time a second cycle passes, in parallel with an update of the focus bias value.

Abstract: An object of the present invention is to provide an optical information recording medium suited for high-density and high-speed recording using a recording wavelength of 360 to 450 nm, in particular, around 400 nm (for example, 405 nm) and its recording method. The present invention is based not on a conventional High to Low method but on a Low to High method and, when the reflectance of the pit is higher than that of the non-pit area, the maximum film thickness of the recording layer at the track area where the pits are arranged is in the range from 25 to 60 nm and the maximum film thickness of the recording layer at the area adjacent to the track area is in the range of 5 to 30 nm, a satisfactory push-pull signal can be obtained. Further, the film thickness of the reflecting layer is preferably set in the range from 120 to 180 nm, and groove width of the reflection layer is preferably set in the range from 85 to 150 nm.

Abstract: A spherical aberration correction mechanism 30 includes a lens holder 35 that holds a collimator lens 16, a main shaft 36a that supports the lens holder 35 in a linearly movable manner, a lead screw 34 supported in a rotatable manner and provided with a screw thread formed of a first slope and a second slope each in a spiral shape on an outer circumference thereof, and a stepping motor 13 that rotates the lead screw 34. The lens holder 35 includes a rack portion 41 disposed between the main shaft 36a and the lead screw 34 and having a slope that abuts on the first slope and first and second stoppers 46a and 46b that regulate a relative position of the rack portion 41 with respect to the lead screw 34 so that the rack portion 41 does not abut on the second slope.

Abstract: An optical disc includes a substrate with a hub, a data storage area, and an outer ring. The hub defines a center hole. The data storage area extends radially from the hub body and is thinner than the hub at the thickest hub portion. The outer ring protrudes down from the outer perimeter of the data storage area. Thicknesses of the outer ring and the data storage area are of a same order of magnitude. The outer edge of the optical disc thus includes the data storage area and the outer ring.

Abstract: An optical recording head includes: a light source; a slider comprising a wave guide which irradiates light from the light source to a recording medium, wherein a grating coupler is formed on an end portion at an opposite side of the waveguide relative to the light source; and an optical element which comprises a diffraction grating and introduces the light from the light source to the grating coupler through the diffraction grating. The optical element deflects the light from the light source so that the light is incident into the grating coupler with a deflection angle larger than 90 degrees with respect to a direction in which the light proceeds when the light is incident into the optical element.

Abstract: Ordinary optical disks need the resetting of recording conditions in the course of recording to cope with changes in ambient temperature, laser temperature, and medium's recording sensitivity. Optical disks for super-resolution reproduction which are intended to reproduce record marks smaller than the optical resolution, thereby increasing the recording density, need the resetting of recording conditions as well as the condition of super-resolution reproduction because the quality of reproduced signals depends largely on the power for super-resolution reproduction. The power for recording as well as the power for super-resolution reproduction is therefore changed in the course of test recording to detect the deviation from the optimum value of the recording condition to obtain the optimum recording power. In this case, it is also desirable to change the power for super-resolution reproduction in proportion to the power for recording.

Abstract: The invention is directed to provide an information recording apparatus having an adjusting process device which performs adjusting processes including an OPC process for optimizing a recording power for each of recording layers on a multilayer information recording medium, and an information recording device which performs an information recording process for each of the recording layers based on a result of the adjusting processes for each of the recording layers. The adjusting process device includes an initial adjusting process device which performs the adjusting processes at a start of information recording with the information recording device only for a start recording layer having the first recording start address, and an intermediate adjusting process device which performs the adjusting processes during information recording process with the information recording device for a recording layer other than the start recording layer.

Abstract: A recording method which optically records two-dimensional data including a positioning mark and data area in a recording medium. In this method, the state of the positioning mark is changed from a first state to at least one second state different from the first state every given number of recording times of such two-dimensional data.

Abstract: Provided are a method for emulating a separate contents memory unit into an optical disk, an optical disk drive using the same, and an optical disk including a security zone. In the method, when an optical disk processing command from a host is present, whether an optical disk is present in the optical disk drive is judged. When the optical disk is not present in the optical disk drive as a result of the judgment, the contents memory unit is executed as a virtual optical disk. An application stored in the contents memory unit is displayed. The optical disk drive includes an optical disk storage unit, a contents memory unit, and a controller. The optical disk storage unit stores or reproduces contents using an optical disk. The contents memory unit stores contents therein and is executed as a virtual optical disk when the optical disk is not present. The controller controls the optical disk storage unit and the contents memory unit, and controls an access to be made, subject to the contents memory unit.

Abstract: An optical device includes a sub-mount 2 mounting first and second semiconductor lasers 1a, 1b and having an onboard part for the semiconductor lasers and an optical-path conversion mirror 7 integrated with each other, and a light receiving element 11 arranged on a light receiving element substrate to have first and second light receiving regions separated from each other by at least one parting line. In the optical device, one light gravity center of an optical spot, which is formed on the light receiving element 11 by homeward flux of light emitted from the first semiconductor laser 1a and reflected by an optical disc 55, and another light gravity center of an optical spot, which is formed on the light receiving element 11 by homeward flux of light emitted from the second semiconductor laser 1b and reflected by the optical disc 55 are together positioned on the parting line.

Abstract: In a multilayer disc has an increased number of recording layers) spaced by spacing from each other, a generation interval between focus error (FE) signals detected from the respective recording layers becomes small. This causes mutual interference between the FE signals and a resulting undesired offset and the like in the signals, leading to a significantly deteriorated quality of the FE signals. To avoid this, in an optical pickup device according to the present invention, detection surfaces are newly added at positions adjacent to the FE signal detection surfaces, a predetermined detection signal obtained from the newly-added detection surfaces is multiplied by a predetermined coefficient value depending on the spacing between the recording layers, and the multiplied signal is subtracted from the original FE signal. As a result, mutual interference between the FE signals can be remarkably reduced.

Abstract: When a user requests a reproduction operation via a remote control, a microprocessor determines whether or not data on a medium of the type selected in advance by a user using the remote control can be reproduced. When the microprocessor determines that data on a medium of the selected type can be reproduced, it selectively reproduces data on the medium of the selected type. When the microprocessor determines that data on a medium of the selected type cannot be reproduced, it sequentially determines whether data on media other than media of the selected type among multiple types of media can be reproduced or not, sets the type of a medium on which data can be reproduced, which is found as a result of the determination, as the type of media to be played, and reproduces data on the medium on which data can be reproduced.

Abstract: Provided are an optical information recording/reproducing apparatus and method capable of managing a wavelength of a light source when information is recorded/reproduced by utilizing holography, and limiting a wavelength of an interference fringe in a medium, and an optical information recording medium. For information recording/reproducing relative to an optical information recording medium by a pickup, a wavelength detector circuit detects a reference wavelength recorded in a storage area of the optical information recording medium, in accordance with the detected reference wavelength, a controller adjusts a wavelength of a light source of the pickup to have an optimum wavelength, and if a temperature detected with a temperature sensor indicates a predetermined change, readjusts the wavelength of the light source of the pickup to have an optimum wavelength.

Abstract: An apparatus for modulating an incident beam includes a body that is non-transmissive and rotatable about an axis perpendicular to a surface of the body. The body has a first set of features including transmissive features with respect to the incident beam along a first radial path at a first radial distance from the axis and a second set of features including data storage features along a second radial path at a second radial distance from the axis. The apparatus also includes a reference sensor disposed over a first position along the second radial path. In the apparatus. the radial distances are different and the numbers of transmissive features and data storage features are relatively prime. When the body is rotating, the first set of features modulate the incident beam and the reference sensor generates a reference signal based on the data storage features traversing the first position.

Abstract: Provided is an optical information reproducing medium for realizing an excellent super resolution reproduction while performing a high-speed reproduction. The optical information recording medium includes a plurality of super resolution layers (13, 15) whose refractive index or attenuation coefficient changes nonlinearly at predetermined temperatures individually corresponding thereto. Individually on at least two of the super resolution layers (13, 15), the light amounts of the laser beams to be irradiated for causing temperatures of the recording medium to reach the predetermined temperatures are different. The recorded information of the optical information recording medium is reproduced by the areas, in which at least one of the plurality of the super resolution layers has changed in optical characteristic nonlinearly whereas at least one of the remaining layers has not changed in optical characteristic nonlinearly is formed as an aperture.

Abstract: The information recording medium (100) of the present invention includes: an information layer (110) including a recording layer (115) capable of changing its phase containing at least one selected from Ge—Te, Sb—Te and Ge—Sb, and two or more dielectric layers (117, 118) disposed on the optical beam incident side with respect to the recording layer (115); and a transparent layer (102) disposed on the optical beam incident side with respect to the information layer (110) adjacent to the information layer, made of a transparent material with respect to the optical beam, and having a refractive index n of 1.75 or more.

Abstract: An optical disk apparatus that includes a movable part having an objective lens for focusing a laser beam onto an optical disk. A lens-holding member holds the objective lens. A protecting member prevents contact of the objective lens with the optical disk. An elastic supporting member supports the movable part, and an actuator drives the movable part toward or apart from the optical disk. The apparatus is constructed not to cause contact of the protecting member with the optical disk in a non-working state of the actuator, even when the elastic supporting member is bent by gravity toward the optical disk.

Abstract: A first light source 1a emits a first light flux with a first wavelength. A second light source 1b emits a second light flux with a second wavelength that is different from the first wavelength and a third light flux with a third wavelength that is different from the first wavelength and the second wavelength. A collimator lens 6, a first objective lens 9, and a second objective lens 10 collect the first to third light fluxes as converged light on an optical disc. A first composite photodetector 13 detects the reflected light fluxes from the optical disc. The first composite photodetector 13 includes a first quartered light-receiving unit 13a that receives a light flux obtained by reflection of at least one light flux from among the first to third light fluxes from the optical disc and a second quartered light-receiving unit 13b that receives a light flux obtained by reflection of the remaining light fluxes from the optical disc.

Abstract: To provide an optical recording medium of which mechanical properties and storage stability will not be impaired, and which will show little deterioration in signal properties even after being left to stand at high temperature under high humidity. An optical recording medium to perform recording/reading by means of blue laser, which has a value of 10 or less as obtained by “error rate after its environmental resistance test/error rate before its environmental resistance test” in error rates obtained before and after its environmental resistance test carried out by leaving the medium to stand for 500 hours at a temperature of 80° C. under a relative humidity of 80%.

Abstract: The position of a write spot on an optical record carrier, during a write operation by an optical recording device, is important for the quality of the data recorded. Radial positioning of the spot may be facilitated by means of tracking spots, signals from which identify the location of the write spot. Signals from the tracking spots may be affected by the characteristics of the optical record carrier in the their vicinity. Specifically, effects arise from the recorded or unrecorded nature of the tracks adjacent each spot. The invention comprises rotation of the means to generate tracking spots such that tracking spots may be placed in an optimum position for recording, regardless of which data layer on an optical record carrier is to be recorded or the recording direction.

Abstract: An optical pickup includes a first source which emits a first beam with a first wavelength; a second source which emits a second beam with a wavelength shorter than the first wavelength; a first collimate lens which collimates the first beam; a second collimate lens which collimates the second beam; a first objective lens which converges the first collimated beam onto an optical disc; and a second objective lens which converges the second collimated beam onto the disc. The first and second objective lenses are arranged in the disc radial direction. The second objective lens is arranged closer to the side of the disc outer circumference than the first objective lens. The first collimate lens is arranged on the right-hand side when the second objective lens is viewed from the first objective lens. The second collimate lens is arranged on the left-hand side when the first objective lens is viewed from the second objective lens.

Abstract: The present invention relates to a device (1) for scanning an optical recording medium (3), comprising an optical unit (5) for reading data from and/or writing data to said recording medium (3) by scanning said recording medium (3) with a radiation beam (21), said radiation beam (21) being positioned on said recording medium (3) in response to a tracking error signal, a tracking means (7) for generating said tracking error signal and a position control means (11) for controlling a radial scanning position of said radiation beam (21) in respect to a track on said recording medium (3).

Abstract: A reproduction signal evaluation unit has: a pattern detection section for extracting, from a binary signal, a specific state transition pattern which has a possibility of causing a bit error; a differential metric computing section for computing a differential metric based on the binary signal of the extracted state transition pattern; an error computing section for computing an error rate predicted based on an integration value that is integrated by an integration section, a count value that is counted by a pattern count section, an integration value that is integrated by another integration section, and a count value that is counted by another pattern count section, and a standard deviation computing section for computing a standard deviation based on the computed error rate.

Abstract: A random access control method is provided, implemented in an optical disc drive for recording data to an optical disc. In the optical disc drive, a buffer stores a plurality of write commands each associated with a data block bound to a destination address. A processor controls the buffer to build a disc write task from the write commands in which addresses are organized in order. A drive unit is controlled by the processor, performing a recording operation to record the data blocks to the optical disc according to the disc write task; wherein the processor further controls the drive unit to verify the recorded data blocks after completing the recording operation.

Abstract: This invention provides a surface plasmon polariton direction change device (1) for changing a propagation direction of a surface plasmon polariton (5). The surface plasmon polariton direction change device (1) includes a metal film support member (2), and a first metal film (3) and a second metal film (4) which are provided on a predetermined surface of the metal film support member (2), are provided adjacently to each other, and are different from each other in effective refractive index.

Abstract: A light receiving device generates photocurrent that corresponds to the quantity of incident light. A capacitor is arranged with one terminal set to a fixed electric potential, and is charged using the photocurrent. A comparator compares the voltage that occurs between both terminals of the capacitor with a predetermined threshold voltage, and generates a judgment signal that corresponds to the comparison result. An initialization switch initializes the voltage that occurs both terminals of the capacitor. A judgment unit acquires, as data which indicates the quantity of light, the level of the judgment signal at a timing after the passage of a predetermined judgment period of time from the commencement of charging of the capacitor using the photocurrent.

Abstract: A method and system for copy protection using complexity and uncomputability are disclosed. According to one embodiment, a computer-implemented method comprises placing protection structures on a media disc. The protection structures comprise complexity structures and imcomputability commands. Unauthorized reproduction of data stored on the media disc is impeded using the protection structures.

Abstract: An optical storage system modulates a laser beam based on a high frequency modulation (HFM) signal and a pattern to be recorded on an optical storage medium. At least one of an amplitude and a frequency of the HFM signal is adjusted when using the light beam to record the pattern on the optical storage medium or read data from the medium.

Abstract: To provide an optical pickup and an optical information device, capable of obtaining excellent signal characteristics for an optical disk on and/or from which recording and/or reproducing are performed using a laser. The optical pickup includes an optical detector, a support holder for holding the optical detector, and an optical base for fixing the support holder. The support holder has at least two notches at its both ends, the optical base has convex portions corresponding to the notches of the support holder, the optical base and the support holder are fixed by photo-curable adhesives for bonding the convex portions and the support holder to each other, and the shortest distance between the side faces of the convex portions, which do not face each other, is equal to or less than the width of the support holder in the direction of right and left ends.

Abstract: The invention provides a method for performing layer changes for an optical disk drive. In one embodiment, the optical disk drive intends to move a focus of a laserbeam emitted by a pickup head from a present layer onto a target layer of an optical disk. First, an amplitude ratio between a first amplitude of a first S-curve of a previous focusing error signal and a second amplitude of a second S-curve of the previous focusing error signal is determined. The object lens is then moved towards a target position for focusing of the laserbeam on the target layer. A focusing error signal is then generated. The focusing error signal is then amplified or attenuated according to the amplitude ratio to obtain an amplified or attenuated focusing error signal. Whether the object lens has reached the target position is then determined according to the amplified or attenuated focusing error signal.

Abstract: A data storage apparatus and method. The apparatus comprises a mounting structure, a motor mechanically attached to mounting structure, and a data storage platter mechanically attached to the motor. The apparatus additionally comprises a single actuator arm comprising a first and second read/write data head or multiple radial movement mechanisms each comprising a read/write data head. The single actuator arm is configured to move axially along an arc and across a top surface of the data storage platter such that the first read/write data head has access to a first section and a second section of the data storage platter and the second read/write data head only has access to the second section of data storage platter. Each radial movement mechanism moves a different read/write data head radially all along a radius of the data storage platter and over and across different sections of the data storage platter.

Abstract: An optical head includes: a slider which moves relative to a recording medium while the slider is floating above the recording medium; an optical waveguide which is provided on a side surface of an end portion of the slider and which has the focusing function of forming a light spot on the recording medium; and a light guide optical system that guides a light pencil to the optical waveguide. A light pencil coupling portion which receives the light pencil from the light guide optical system is provided in a surface parallel to a direction in which the light pencil is guided by the optical waveguide; and a reflective surface which deflects the light pencil to the light pencil coupling portion is provided in the light guide optical system. The light pencil coupling portion has the function of correcting aberration resulting from oblique incidence of the light pencil obliquely incident from the light guide optical system.

Abstract: A super-resolution optical recording medium (10) of the present invention includes: a medium information region (1) on which medium identification information is recorded; a content region (3) on which content information is recorded; and a blank region (2) provided between the medium information region (1) and the content region (3) and in which at least two tracks are provided so as to connect a train of prepits in the medium information region (1) and a train of prepits in the content region (3). No information is recorded on the blank region (2). With this arrangement, the present invention provides a super-resolution optical recording medium in which a region on which medium identification information is recorded and a region on which content information is recorded are different in track pitch and in which a reproduction error hardly occurs when reproduction shifts from the region on which the medium identification information is recorded to the region on which the content information is recorded.

Abstract: The present invention provides a recording/reproducing device which shortens time required for dubbing, when a user performs the dubbing of program data. The recording/reproducing device of the present invention is a recording/reproducing device which records and reproduces information, including: a tuner control unit 4 which obtains first information; a recording/reproduction control unit 13 which records, in an HDD 15, the first information obtained by the tuner control unit 4, and records, in an optical disc held in the optical disc drive 14, second information which is information having the same content as the first information; a CPU 5 which invalidates the second information; and a user input control unit 9 which receives an instruction requesting the first information recorded in the HDD 15 to be recorded in the optical disc. In the case where the user input control unit 9 receives the instruction, the CPU 5 validates the invalidated second information.

Abstract: An optical pickup device has an astigmatism element, a polarization setting element, and a polarizer. The astigmatism element converges laser light reflected on a disc in a first direction and a second direction to form a first focal line and a second focal line. The polarization setting element makes polarization directions of light fluxes different from each other, the light fluxes being obtained by dividing a light flux of the laser light transmitted through the astigmatism element into two by a straight line parallel to the first direction. The polarizer transmits light having polarization directions obtained by inverting the polarization directions set by the polarization setting element with respect to the straight line parallel to the first direction, respectively.

Abstract: Provided is an objective lens for recording a hologram that condenses an recording beam on a hologram recording medium, and the objective lens is configured so as to condense, in the case where the recording beam is incident upon the objective lens in a form of a parallel beam flux, an on-axis beam flux and an off-axis beam flux contained in the parallel flux so as to form a beam waist in the hologram recording medium, and such that a distance between an off-axis image point of the off-axis beam flux that defines a largest field angle among the off-axis beam fluxes gradually converging ahead of the beam waist and the hologram recording medium becomes minimal.