Abstract: An optical pickup includes a light source 1; a diffraction element 2 for generating a write main beam and a read sub-beam via diffraction; an objective lens 5; a wavelength plate 9; a polarization hologram element 7 having a plurality of diffraction regions with different diffraction characteristics, designed so that each diffraction region separates a light beam reflected from the optical storage medium and transmitted through the wavelength plate into a 0th order light beam and ±1st order light beams; an actuator 11; and a photodetector 10 configured to detect a light beam reflected from the optical storage medium 6 and diffracted by the polarization hologram element 7.

Abstract: A recording medium is provided with: a guide layer on which a guide track or tracks are formed; and a plurality of recording layers, wherein a same mark group is formed in a same rotational phase position of each of a plurality of guide tracks which are included in a beam spot of guide laser light, the mark group including a pair of record marks which are shifted by a predetermined distance toward a right side and a left side, respectively, from a track center.

Abstract: An exemplary optical pickup comprises: a light source with first and second emission points; an optical branching element which branches light emitted from the first emission point into multiple light beams including a first main beam and first sub-beams and which also branches light emitted from the second emission point into multiple light beams including a second main beam and second sub-beams; an optical system which condenses the multiple light beams produced by the optical branching element onto an optical storage medium, thereby making the first and second main beams form a write light beam spot and a read light beam spot, respectively, on a target recording track on the storage medium and making the first and second sub-beams form reference light beam spots and other light beam spots somewhere on the storage medium other than the target recording track.

Abstract: Present novel and non-trivial optical, laser-based measuring systems and method are disclosed. An optical, laser-based, or LIDAR measuring apparatus is comprised of a radiation receiver/transmitter, a beam-forming optical element, a beam steering device comprised of a deviation optical element and at least one actuator used to steer the deviation optical element in response to drive signal(s) from a processor.

Abstract: In one embodiment, an optical pickup includes an optical system which forms multiple light beams based on the light emitted from a light source and which converges a write beam and a read beam, thereby forming a main spot and a sub-spot, respectively, on an optical storage medium. This optical system converges the write and read beams onto the optical storage medium so that the main spot moves through the same region on the optical storage medium ahead of the sub-spot. The optical pickup further includes a detector for sensing the write and read beams reflected from the storage medium. The detector includes a first photodiode 10 that receives the reflected light from the main spot 50R on the storage medium and a second photodiode 11 that receives a portion of the reflected light from the sub-spot 51R.

Abstract: An exemplary optical pickup comprises: first, second and third photosensitive elements which are arranged to respectively receive a main light beam and first and second sub-light beams reflected from an optical storage medium; and fourth and fifth photosensitive elements which are arranged to receive the rest of the light that has also been emitted from a light source but has not been reflected from the optical storage medium. A signal that has been written on the optical storage medium with the main light beam for writing is read by performing an arithmetic operation on the signal output of the second or third photosensitive element and that of the fourth photosensitive element.

Abstract: An optical read/write apparatus as an embodiment of the present invention includes: a light-splitting element configured to split a light beam emitted from a light source into multiple light beams including a write beam and a read beam; an optical system configured to converge the write and read beams onto the same track on an optical storage medium; a photodetector including a light receiving element configured to detect the read beam reflected from the optical storage medium and output an electrical signal; and a divider configured to generate a read signal by dividing the signal detected by the light receiving element by a signal that represents a write modulated component and that is obtained by detecting a part of the light beam emitted from the light source.

Abstract: Provided is an optical disc drive device which stably controls an actuator of an optical pickup, by individually controlling an optical spot when following the guide track and an optical spot when recording/reproducing information on/from each recording layer. An optical spot when following the guide track and an optical spot when recording/reproducing information on/from each recording layer are individually controlled. At this time, the optical spot exclusive for the track and the optical spot exclusive for the recording/reproducing are formed on an optical disc.

Abstract: Systems and methods for data storage on an optical medium having a plurality of tracks include splitting a light beam into a higher power main beam and at least one lower power side beam that form corresponding spots spaced along a selected one of the plurality of tracks and selectively positioning and aligning the beams/spots along the selected one of the plurality of tracks using the higher power main beam to write data while reading previously written data using the at least one lower power side beam. The systems and methods may include correlating the read signal with a time-shifted write signal to provide a direct read after write capability to verify data written to the optical medium. In one embodiment, an optical tape drive includes an optical pickup unit (OPU) that generates a lower power satellite beam to read data directly after writing by a higher power main beam.

Abstract: An optical drive device generates a first push-pull signal and a first sum signal based on a light receiving amount in two light receiving areas of which each width in a signal light tangent direction is smaller than a diameter of a spot of signal light, generates a first normalized push-pull signal by normalizing the first push-pull signal by using the first sum signal, and generates a tracking error signal based on the first normalized push-pull signal.

Abstract: Disclosed herein are an optical recording medium driving device and an additional recording method, which performs tracking servo control for moving an objective lens in a direction orthogonal to a tangential direction of a guide track so that a guide tracking error signal is decreased with respect to a guide track of a guide layer separation type recording medium, detects an additional recording start position subsequent to a recorded track if the recorded track is present in a recording layer of the optical recording medium, generates a tracking correction signal according to the reproduction tracking error signal upon tracking servo control of the recorded track just before the additional recording start position, and corrects tracking servo control according to the tracking correction signal upon additional recording start.

Abstract: An objective lens includes a diffraction structure for distributing much of a quantity of an incident light beam into two diffracted lights having different diffraction orders from each other, wherein recording or reproduction of information on an optical disk is performed by converging the diffracted light having a longer focal length of the two diffracted lights onto an information recording surface through a protective layer of the optical disk, and a distance from the objective lens to a surface of the protective layer along an optical axis is longer than a distance between focuses of the two diffracted lights along the optical axis when the diffracted light having the longer focal length is converged onto the information recording surface of the optical disk.

Abstract: Provided is a medium capable of implementing a large-capacity recording at low cost per bit. A medium including a network of metal wires and recording materials each provided at an intersection of the metal wires. Surface plasmons are made to propagate along the metal wires. Two surface plasmons are made to propagate in two different directions and to collide with each other at a certain position. Multiple-layer recording is carried out by changing the recording materials at the certain position.

Abstract: In one example embodiment, a recording apparatus includes a laser and a controller. In one example embodiment, the recording apparatus records a second recording track on a recording medium which includes a first recording track which was previously recorded on the recording medium. In one example embodiment, the second recording track is gradually enlarged until a first separation distance exceeds a distance which corresponds to at least twice a number of maximum deviation tracks of the first recording track.

Abstract: A write analysis system is described for an optical drive, where the optical drive includes an optical storage medium. The write analysis system includes a filter that receives a reflected signal that is based on a reflection of a diffracted laser beam. The reflection of the diffracted laser beam includes a reflection of a first write signal. The filter generates a filtered signal by filtering the first write signal from the diffracted laser beam. The system also includes a read-back module that receives the filtered signal and that compares the filtered signal to a second write signal that was written to the optical storage medium prior to the first write signal.

Abstract: An optical-pickup apparatus comprising: a laser-light source; a diffraction grating including first-and-second regions of periodic structures different in phase from each other and a third region whose periodic structure is different in phase from the first-and-second regions; an objective lens focusing main-and-sub-luminous fluxes generated by the diffraction grating on the same optical-disc track; and a photodetector to receive reflected light of the main-and-sub-luminous fluxes from an optical disc and output a detection signal for generating main-and-sub-push-pull signals, a relationship between an incident light width in the objective lens corresponding to the third region and pupil diameters of the objective lens corresponding to first-and-second wavelengths of laser lights being adjusted so that a ratio of minimum value to maximum value of a differential-push-pull-signal is at substantially 50% or more and a ratio of sub-push-pull-signal level to main-push-pull-signal level is at substantially 15% or m

Abstract: A disk drive controls the rotational speed of a disk to an appropriate value. A system controller of the drive stores data read from a disk and read-ahead data into buffer memory. A time interval ti at which the buffer memory becomes full is measured, and the time interval ti is compared with a predetermined lower limit value t1 and a predetermined upper limit value t2. When a relationship of ti>t2 stands, rotational speed is increased. When a relationship of ti<t1 stands, control is performed in such a way that the rotational speed is decreased so as to achieve t1?ti?t2.

Abstract: An optical information recording device includes: a section that acquires recording information that should be recorded on an optical information recording medium on which information are recorded by forming a recording mark at a position where an optical beam is focused on and from which the information are reproduced based on the reflectance of the recording mark; a section including at least one or more one-surface beam emission sections that emit a recording beam according to part of the recording information to one surface of the recording medium and focus the beam on a target position to form the recording mark; and an section including at least one or more other-surface beam emission sections that emit an recording beam according to the rest of the recording information to the other surface of the recording medium and focus the beam on a target position to form the recording mark.

Abstract: An optical disc drive for recording and/or reading information on or from an optical disc is disclosed. The optical disc drive includes: a position controller which controls the position of the objective lens based on the position-controlling light beam reflected by the reflective surface by condensing the position-controlling light beam by the objective lens such that the position-controlling light beam is brought to a focus at a target guide position on the reflective surface corresponding to the target recording position; a tilt angle detector which detects tilt angle of the optical disc relative to optical axis of the position-controlling light beam; and a focal position corrector which makes a correction such that a focal position obtained when the information light beam is condensed by the objective lens is aligned to the target recording position according to the tilt angle.

Abstract: A holographic storage and reproduction system and method with a servo are provided, wherein a servo mechanism is provided, such that the holographic interferogram is continuously stored in the holographic recording medium. When a reproduced signal is to be obtained, it can be retrieved quickly and accurately through the servo mechanism. Also, the intensity distribution of the reference light reflected by the holographic recording medium can be monitored and controlled, such that the relative distance and oblique angle between the storage and reproduction system and the holographic recording medium are analyzed and adjusted.

Abstract: Embodiments of methods and systems for controlling access to information stored on memory or data storage devices are disclosed. In various embodiments, fluid-mediated modification of information or access to information is utilized. According to various embodiments, data storage devices designed for rotating access are described which include rotation-activated fluid control mechanisms.

Abstract: An optical information recording device includes: a section that acquires recording information that should be recorded on an optical information recording medium on which information are recorded by forming a recording mark at a position where an optical beam is focused on and from which the information are reproduced based on the reflectance of the recording mark; a section including at least one or more one-surface beam emission sections that emit a recording beam according to part of the recording information to one surface of the recording medium and focus the beam on a target position to form the recording mark; and an section including at least one or more other-surface beam emission sections that emit an recording beam according to the rest of the recording information to the other surface of the recording medium and focus the beam on a target position to form the recording mark.

Abstract: Data is written on a plurality of data tracks on an optical disk by a plurality of laser beams. The spots illuminated by the beams are spaced apart to prevent thermal interference. The spots are aligned along a line at an angle to the tangent of the data tracks. The angle of the line of spots is determined by an equation using variables that include the track pitch, the minimum distance between spots and the difference in track numbers between tracks being written.

Abstract: An optical recording/reproducing apparatus includes an optical pickup and a signal processor. The optical pickup includes an optical splitting device which splits light emitted from a first light source into a main light beam and sub-light beams which are symmetrical with respect to the main light beam and irradiates the split light beams on a recording medium, and a light detection device which receives the main light beam and the sub-light beams reflected by the recording medium, so as to detect a tracking error signal in a three-beam method and one of a push-pull method and an improved push-pull method.

Abstract: A disk recording apparatus for recording data to a disk includes: a reading and writing element for emitting a read beam onto the disk to read out recorded data therefrom while emitting a plurality of write beams simultaneously onto the disk to record data thereto in parallel; and a controlling element for controlling where to emit on the disk the plurality of write beams in accordance with the data read out by the reading and writing element.

Abstract: Disclosed is a track-search control circuit for performing track-search of an optical disc stably even at the time of multi-speed reproduction of the optical disc.

Abstract: In a method and an apparatus for aberration correction according to the invention, aberration occurring in recording/reproducing information derived from causes such as thickness variation of a substrate, a tilt, a focus error and a tracking error is detected, and the aberration is corrected by correcting these causes.

Abstract: A data storage apparatus includes an array of optical fibers. The array has a first end and a second end. The first end of the array includes multiple optical fiber ends, each optical fiber end having an end face adapted for receiving light of a wavelength ? into the fiber for conveyance to the second end of the fiber array. The second end of the array includes multiple tapered optical fiber tips, each tapered optical fiber end having a minimum diameter less than ?. An opaque coating covers a portion of the tapered optical fiber tips. The data storage apparatus also includes a photochromic medium located within a distance ? of the second end of the array.

Abstract: Data is written on a plurality of data tracks on an optical disk by a plurality of laser beams. The spots illuminated by the beams are spaced apart to prevent thermal interference. The spots are aligned along a line at an angle to the tangent of the data tracks. The angle of the line of spots is determined by an equation using variables that include the track pitch, the minimum distance between spots and the difference in track numbers between tracks being written.

Abstract: An optical system of an optical disk recording apparatus irradiates a disk with a main beam for use in writing a data signal onto a disk and a sub-beam succeeding the main beam. When writing a data signal onto the disk, a site on the disk at which a data signal is written by the main beam is subsequently irradiated with the succeeding sub-beam. Light of the succeeding sub-beam reflected from the disk is received by a succeeding light receiving sub-region. A sampling circuit samples a signal at periods when the emission power of the main beam is at the recording level, among output signals from the succeeding light receiving sub-region. Based on the sampled signal at the recording level, a ? value detection circuit and a jitter amount detection circuit obtain a ? value and a jitter amount indicative of the recording state of the data signal recorded on the disk, respectively.

Abstract: In an optical recording apparatus having an optical pickup, a rotating section is provided for rotating an optical disk which is formed thereon with a guide groove to define a spiral track having a plurality of rounds. The optical pickup has a light source for generating an optical beam and a diffractive grating for diffracting the optical beam to form a main beam and a pair of sub beams opposite with each other relative to the main beam. The optical pickup is operable for irradiating the main beam to the spiral track with accompanying the pair of the sub beams along apposite sides of the spiral track. A servo section operates the optical pickup to enable the main beam to trace the spiral track based on a tracking error signal derived from return lights of the sub beams reflected back from the optical disk. A recording section modulates the main beam for recording of information onto the spiral track while the optical dick is rotated.

Abstract: There are provided an information write device and an information read device enabling to generate highly accurate contrast signals. When a main light spot Pc is located at the center of the a groove G, the light spot Pc and sub light spots Psa, Psb are each adapted to radiate a disc DSC such that the sub light spots Psa, Psb radiate positions displaced from the center of the land L. The reflected beams of light from the disc DSC caused by the radiation with the light spots Pc, Psa, Psb are detected to generate push-pull signals each corresponding to the light spots Pc, Psa, Psb, respectively, in accordance with each of the detected signals. Furthermore, a signal to be obtained by amplifying an addition signal, given by adding the push-pull signals each corresponding to the sub light spots Psa, Psb, with a predetermined amplification factor K/n, and a push-pull signal corresponding to the main light spot Pc are added to thereby generate a contrast signal.

Abstract: There is disclosed an optical device in which a first light source for outputting a first wavelength light is apart from a second light source for outputting a second wavelength light by a predetermined distance. An information recording medium is irradiated with the first and second wavelength lights transmitted through a holographic optical element having first and second diffraction areas. The first and second diffraction areas are provided with grating arrangements in which grating axis directions are parallel to each other and grating pitches are different from each other. The first and second wavelength lights reflected by the information recording medium are transmitted through the holographic optical element and diffracted by the first and second diffraction areas.

Abstract: Focusing control for maintaining a distance between an objective lens and a recording medium constant is executed using light whose wavelength is longer than that of recording light and whose detection sensitivity is better than that of the recording light, and a deviation of a focal point of the recording light is detected using reflected light which is reflected by the recording medium to thereby correct a control target position for a focusing control circuit, whereby the distance between the objective lens and the recording medium is corrected to a desirable distance throughout recording. In this manner, excellent focusing control is performed on recording light which has a low detection sensitivity and belongs to the UV range, while correcting a focusing control position for the recording light throughout recording.

Abstract: A method and apparatus are disclosed for a multi-channel imaging system wherein the beams of light corresponding to each channel can be individually auto-focussed. Individual channel focussing permits image data to be recorded on a surface of variable depth, such as the patterned surfaces of semiconductor wafers and masks. A light source illuminates an array of reflective, deformable, micromachined ribbons and the ribbons reflect the light to form beams for the various channels. An auto-focus detector determines the depth profile of a recording surface and focus data for each channel is fed back to the ribbon array. The focus data for a particular channel is used to control the deformation of a corresponding ribbon and consequently, the focal length of the reflected beam. The individual beams can be modulated with image data by an external modulator or by the ribbon array itself.

Abstract: 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.

Abstract: Two light sources radiating two light beams having different wavelengths are simultaneously operated. Reflected beams of these two types of laser beams from an optical recording medium are simultaneously detected by two detectors. When one of the two types of light beams having different wavelengths is used while being focused on an optical recording medium, the spot diameter of the other non-focused metering beam on the optical recording medium is set larger than that of the one of the two light beams. A reflected light having a larger spot diameter is used to reduce DC offset in a tracking error signal.

Abstract: The invention relates to caching data in a data processing system including a host computer and a storage subsystem including at least one customer disk and a cache disk. Write transactions are received specifying data to be written to at least one customer disk and these are cached in a volatile memory of the storage subsystem and written to the cache disk. The transaction data is written sequentially to the cache disk when available. In the intervening periods (i.e., when no transaction data is available), padding data is instead written sequentially to the cache disk.

Abstract: An optical disk unit, which performs tracking control by generating a tracking error signal based on detection signals of reflected lights of a main light beam for recording and reproduction and sub light beams for tracking, includes a first tracking error generation part generating a first tracking error component from the detection signals of the reflected light of the main light beam of a read-power time or an erase-power time, a second tracking error generation part generating a second tracking error component from the detection signals of the reflected lights of the sub light beams of a write-power time, and a subtraction part obtaining the tracking error signal for a recording time by subtracting the second tracking error component from the first tracking error component.

Abstract: An optical disk apparatus of the present invention includes: a light irradiator operable to converge a light beam and to irradiate an information carrier (a recording medium) with the converged light beam; a moving means operable to move a converging point of the light beam in a direction substantially perpendicular to a surface of the information carrier; and a focusing controller operable to control the moving means to place the converging point of the light beam at a predetermined position.

Abstract: In an exposure apparatus and an exposure method, a disc master to be used in the preparation of an optical disc is applied to an exposure device, making it possible to perform exposure on a disc master for an optical disc which is substantially improved in recording density. An exposure laser beam by SHG having a wavelength of 300 nm or less is modulated by a modulator, and applied by near field effect to a disc master by using an objective lens having a numerical aperture of 1.0 or more.

Abstract: The present invention relates to an optical device with a variable numerical aperture (NA), which utilizes special optical properties of a liquid crystal medium. Through the design of external electrodes and a circuit control unit, the refraction index of the liquid crystal medium can be modulated by the external voltage so that the beam passing through the LCD produces diffraction. An optical device with a variable focal point is thus formed by combining this LC diffractive device and an objective lens. So the present invention provides an optical device with focal points of different numerical apertures by varying the external voltage, whereby the device can read optical disks of all specifications.

Abstract: An optical system of an optical disk recording apparatus irradiates a disk with a main beam for use in writing a data signal onto a disk and a sub-beam succeeding the main beam. When writing a data signal onto the disk, a site on the disk at which a data signal is written by the main beam is subsequently irradiated with the succeeding sub-beam. Light of the succeeding sub-beam reflected from the disk is received by a succeeding light receiving sub-region. A sampling circuit samples a signal at periods when the emission power of the main beam is at the recording level, among output signals from the succeeding light receiving sub-region. Based on the sampled signal at the recording level, a &bgr; value detection circuit and a jitter amount detection circuit obtain a &bgr; value and a jitter amount indicative of the recording state of the data signal recorded on the disk, respectively.

Abstract: Focusing method and exposure apparatus for focusing both a parallel light beam and a non-parallel light beam through a movable objective lens onto an object. A negative feedback loop is provided which has a detector for receiving a reflection light beam of the non-parallel light beam passed through the movable objective lens, reflected at the object and passed through the movable objective lens, for generating a detection signal corresponding to a focus deviation of the non-parallel light beam, and a driver for receiving the detection signal to control a position of the movable objective lens in accordance with the detection signal, so that the detection signal is decreased. The negative feedback loop further includes a correction signal generator for generating a correction signal and supplying it to the negative feedback loop as a disturbance of the loop so that the parallel light beam is focused onto the object.

Abstract: An optical pickup device comprises a stationary optical system and a movable optical system. The stationary optical system includes a recording/reproducing laser, a collimator for the recording/reproducing laser, a servo laser, a collimator for the servo laser, an actuator for moving the collimator for the servo laser along its optical axis, and a beam coupling/splitting optical element. The movable optical system includes an objective lens and an actuator for moving the objective lens along its optical axis. The point of convergence of recording/reproducing laser light is suitably moved in the layer direction in a recording layer of an optical disk. It is moved in a manner such that the collimator for substantially collimating servo laser light is first moved along its optical axis and the objective lens is then moved along its optical axis to correct defocusing of the servo laser light that is caused by the movement of the collimator for the servo laser light.

Abstract: Apparatus for simultaneously recording and reading information on a medium moveable in forward and reverse directions includes a first record laser and means for establishing a first beam path for recording information on the moveable medium and a second read laser and at least one read-out detector and means for establishing a beam path so that the light from the second laser illuminates the medium and is reflected to the detector which reads recorded information.

Abstract: A dynamic control diffraction grating for dynamically varying a light amount ratio of a zero-order diffracted beam of light to high-order diffracted beams of light. The dynamic control diffraction grating comprises a voltage-dependent phase varying material for transmitting a beam of light therethrough and varying the phase of the transmitted light beam in response to external voltages applied thereto, the voltages having different levels and being applied to the phase varying material at regular intervals in a comb form.

Abstract: There is an optical pickup apparatus 200 using a semiconductor laser element 50 having a first light emission part 36 and a second light emission part 40, wherein it is constructed so that in case that the first light emission part 36 is placed in a position in which an image height does not occur and the second light emission part 40 is placed in a position in which an image height occurs, when the first light emission part 36 is driven, the same focus driving currents are supplied from a focus driving part 120 and when the second light emission part 40 is driven, an objective lens 54b is driven in a focus direction with the objective lens inclined by generating an offset value having a predetermined value from an offset generation part 126 and varying one of the focus driving currents of the focus driving part 120.

Abstract: Two light sources 2, 3 radiating light beams having different waveforms are simultaneously operated. Reflected beams of these two types of laser beams from an optical recording medium are simultaneously detected by detectors 4, 5. When one of the two types of light beams having different wavelengths is used while being focused on an optical recording medium, the spot diameter of the other non-focused metering beam on the optical recording medium is set larger set larger than that of the one of the two light beams. A reflected light having a larger spot diameter is used to reduce DC offset in a tracking error signal.

Abstract: A method of manufacturing an optical disc master from a glass substrate includes coating the substrate with a layer of photoresist, and applying an alkali-gel layer atop the photoresist. The coated substrate is then placed in an environment with a higher than normal humidity. The surface of the coated glass is selectively exposed to a beam of a writing laser, the exposure being controlled by digital information to be recorded on the disc. Exposed portions of the coated substrate experience a chemical reaction between the photoresist and the alkali material in the humid environment. Exposed portions are then developed and ablated thereby creating the pits and lands.