Abstract: An amplifier circuit and an optical pickup device supporting multi-layered optical discs and hi-speed play mode. The amplifier circuit includes photodiodes 11 to 15; operational amplifiers 21 to 25; feedback resistors 31 to 34; resistors 41 to 45; output terminals 51 to 55; reference voltage sources 56 and 57; a reverse-bias-voltage control circuit 61; and a parasitic-capacitance detecting circuit 65. The reverse-bias-voltage control circuit 61 is connected to the cathodes of the photodiodes 11 to 15. The parasitic-capacitance detecting circuit 65 detects the parasitic capacitance of the photodiode 15. The reverse bias voltage generated in the reverse-bias-voltage control circuit 61 is adjusted according to the detection result by the parasitic-capacitance detecting circuit 65, so that the optical sensitivity of the photodiodes 11 to 14 is maintained at an appropriate value.

Abstract: An optical disc apparatus, for executing recording or reproducing on an optical disc having at least two (2) or more of recording/reproducing layers, comprises an optical pickup, having: a sphere aberration compensating portion, which is configured to set up a compensation volume of the sphere aberration; an objective lens; and a driver portion, which is configured to drive the objective lens, wherein the sphere aberration compensating portion sets up the compensation volume to that corresponding to an intermediate position between a deepest layer and a most front layer from the optical pickup; the driver portion drives the objective lens to come close to the optical disc, when the compensation volume is set to that corresponding to the intermediate position; the sphere aberration compensating portion sets up the compensation volume to that corresponding to the deepest layer, when the objective lens is driven in a direction of coming close to the optical disc; and the driver portion drives the objective lens

Abstract: A thin-type optical head, smaller in optic mounting spaces comprising to the conventional one, in an optic system enabling with BD including a 2-layers BD, DVD an CD, comprises a light source, for emit a light beam therefrom; an optical branch element for penetrating a predetermined amount of lights, therethrough, of an incident light beam thereon, and to reflecting remaining amount of lights thereupon; a light focusing element for focusing the light beam upon an optical information recording medium; a photo detector for receiving the light beam reflecting upon the optical information recording medium; and an optical path converter element for converting an angle of an optical path, on which the light beam propagates, wherein the optical path converter element is disposed on an optical path of the light beam between the optical branch element and the photo detector, or between the optical branch element and the light source, and has an incident surface, upon which the light beam enters, and an emission surfac

Abstract: According to the present invention, of all beams of light reflected from the optical disc, only light in a peripheral region excluding a push-pull region is used to generate a DPD signal. In this method of signal generation that optimizes internal light-receiving surface interconnections in a photodetector, the lens error signal required for the generation of a tracking error signal in the DPP scheme is amplified at a lower amplification factor. In addition, the light reflected from the multilayered optical disc will be divided into a plurality of regions and the divided beam of light will be focused at different positions on the photodetector. When the beam is focused upon a desired layer, stray light from recording layers other than those to be subjected to information reproduction will not enter the photodetector light-receiving surfaces used for servo signals.

Abstract: An optical disc fixing device and an optical disc drive using the optical disc fixing device are provided. The optical disc fixing device is configured for fixing an optical disc thereto. The optical disc defines a circular mounting hole at the center portion. The optical disc fixing device includes a cylindrical clamping chassis, at least one latching piece, at least one elastic member, and a control member. The clamping chassis is substantially the same shape as the mounting hole of the optical disc and has a peripheral sidewall. The at least one latching piece together with the at least one elastic member are assembled within the clamping chassis. The control member is releasably assembled to the clamping chassis for extending the at least one latching piece from the peripheral sidewall of the clamping chassis to hold the optical disc.

Abstract: An optical disc drive according to the present invention can write information on an optical disc, which includes a substrate on which a number of pre-pits 2 have been formed on its tracks and a recording film that is supported on the substrate. The drive includes an optical pickup and a writing control section for controlling the optical pickup so that marks 3 are recorded so as to overlap with some of the pre-pits 2 on the tracks and for making the optical pickup irradiate the recording film with a writing light beam. The writing control section changes the interval of each pair of recorded marks that are adjacent to each other along the radius of the optical disc according to the optical power of the writing light beam. Thus, the optical disc drive of the present invention can record a mark on an optical disc on which pre-pits have already been formed even if the optical disc has a simplified structure.

Abstract: An optical head device compatible to different types of optical discs and capable of guaranteeing a sufficiently wide dynamic range for a low density optical disc, and the like are provided. The optical head device includes a plurality of light sources switchably usable; an objective lens for converging light emitted from one of the plurality of light sources to an information recording layer of an optical disc; and a light detector for receiving the light reflected by the information recording layer and outputting an electric signal based on the amount of the received light. The plurality of light sources include a first light source for emitting light having a first wavelength and a second light source for emitting light having a second wavelength shorter than the first wavelength.

Abstract: An optical disc apparatus and a control method for the optical disc apparatus are provided. A control method for an optical disc apparatus according to one embodiment of the present invention may comprise rotating a disc through a spindle motor if a type of a disc loaded in the optical disc apparatus is determined; and carrying out servo operation which can be processed irrespective of rotation speed of the disc while checking whether the rotation speed of the disc equals a predetermined speed. Servo operation which can be processed independently of the rotation speed of the disc can correspond to operation related to focusing servo and additionally to operation related to tracking servo. Therefore, since the time the user has to wait for requested video, music, or data to be extracted after the user has inserted a medium is reduced, user convenience can be improved.

Abstract: An optical disc drive according to the present invention includes an optical pickup and a writing control section for instructing the optical pickup to record a mark, representing the information to be written, on the optical disc. In recording the mark on the optical disc, the writing control section instructs the optical pickup to irradiate the same area on the optical disc with a light beam a plurality of times so that the mark is recorded in that repeatedly irradiated area.

Abstract: According to one embodiment, an optical information recording apparatus includes a spatial light modulator, an optical mechanism, a driving module, and a controller. The spatial light modulator converts an irradiation beam emitted from a light source to plural partial information beams that carry information by causing the irradiation beam to pass through plural modulation areas. The optical mechanism collects the partial information beams onto an optical information recording medium and applies a reference beam onto the recording medium such that the reference beam and the partial information beams intersect with each other on an information recording layer. The driving module drives the recording medium or the optical mechanism. The controller performs angle multiplex recording of information on the information recording layer by controlling the driving module and causing the light source to emit the irradiation beam while switchingly supplying the modulation areas with the information.

Abstract: An optical encoder includes an optical encoding disc, a light source module, a motor, and an optical detection system. The optical encoding disc includes a plurality of concentric annular tracks. Each track includes a plurality of coding units. Each coding unit includes a light converging portion and a light diverging portion. The light converging portions and the light diverging portions are arranged alternately along a circumferential direction of the optical encoding disc. The motor is configured for driving the optical encoding disc to rotate. The optical detection system includes a plurality of photo-detectors arranged in a line parallel to a radius of the optical encoding disc. Each photo-detector is corresponding to each track of the optical encoding disc respectively. Each photo-detector is configured for receiving the light beam transmitted through the corresponding track, and generating a voltage according to an intensity of the received light beam.

Abstract: An optical information medium measurement method of the present invention, for measuring a degree of modulation in an optical information medium of a multilayered structure having a plurality of information layers, includes a first step of measuring the modulation degree of each layer of the optical information medium, by use of a measurement optical system, a second step of obtaining a thickness between layers of the optical information medium, a third step of obtaining a reflectance of each layer of the optical information medium, and a fourth step of converting the modulation degree of each layer, the modulation degree being measured in the first step, into a modulation degree at a reference optical system differing from the measurement optical system, based on a value indicative of the thickness between layers, the thickness being obtained in the second step, and a value indicative of the reflectance of each layer, the reflectance being obtained in the third step.

Abstract: Disclosed is a digital information media having an adhesion promotion layer supported on a dummy (L1) substrate that enables secure bonding of the L1 layer, directly or indirectly, to the rest of the stack of layers in the digital information media. Certain materials including metals, metal alloys, or metalloids enhance adhesion between the adhesive layer and the L1. By applying an adhesion promotion layer of such materials on an inner surface of the L1, the bond between the adhesive and the adhesion promotion layer improves bonding and reduces a tendency for the L1 to delaminate from the rest of the stack. The tendency for breakage of the media at the juncture between the adhesion promotion layer and the adhesive is reduced, and incursion of moisture or oxygen through the interface between the adhesion promotion layer and the adhesive is inhibited.

Abstract: The invention provides a method for determining the layer type of a blu-ray disk. First, a laser beam is focused on a target layer of the blu-ray disk. Reflection of the laser beam from the target layer is the detected to obtain a reflection signal. The reflection signal is then processed to generate a first tracking error signal and a second tracking error signal. Magnitudes of the first tracking error signal and the second tracking error signal are then measured. The magnitude of the second tracking error signal is then subtracted from the magnitude of the first tracking error signal to obtain a difference value. Finally, the layer type of the target layer is determined by comparing the difference value with the first predetermined threshold.

Abstract: A device for preventing and controlling copying of data from an optical storage disc utilizing physical modifications in or on a storage capable optical disc. Also described is, a method for authenticating and controlling reading or copying of information or data in or on optical discs as, for example, wherein a locus on or in the optical storage disc is initially read to produce a signal and is then re-read by a reader to produce a second signal. The signal detected upon re-reading is different from the signal that is detected upon initial sampling.

Abstract: A vertical cavity surface emitting laser that includes: a substrate; a first semiconductor multilayer reflector; an active region; a second semiconductor multilayer reflector; a columnar structure formed on the substrate; a current narrowing layer that is formed inside of the columnar structure, and has a conductive region surrounded by an oxidization region selectively oxidized; a first electrode that is formed at a top of the columnar structure, and defines a beam window; a first insulating film that covers the beam window; and a second insulating film of which a second refractive index is larger than the first refractive index. A reflection ratio in a second region where the second insulating film is formed is lower than a reflection ratio in a first region where only the first insulating film is formed.

Abstract: An optical disc drive apparatus includes: a first optical pickup and a second optical pickup which record data on an optical disc and reproduce data recorded on the optical disc; a slide mechanism which has the first and second optical pickups mounted thereon to slide the first and second optical pickups in a radial direction of the optical disc; a seek command receiver which receives a seek command; a first optical pickup controller which causes the first optical pickup to perform a search on the basis of the seek command received by the seek command receiver; a slide mechanism controller which controls the slide mechanism on the basis of the seek command received by the seek command receiver; and a second optical pickup controller which turns off a tracking servo of the second optical pickup when the first and second optical pickups are slid by the slide mechanism.

Abstract: A signal evaluation method according to the present invention is a method for evaluating a read signal, retrieved from an information recording medium, based on a binarized signal generated from the read signal by a PRML method.

Abstract: An extreme ultraviolet light system includes a drive laser system that produces an amplified light beam; a target material delivery system configured to produce a target material at a target location; a beam delivery system configured to receive the amplified light beam emitted from the drive laser system and to direct the amplified light beam toward the target location; and a metrology system. The beam delivery system includes converging lens configured and arranged to focus the amplified light beam at the target location. The metrology system includes a light collection system configured to collect a portion of the amplified light beam reflected from the converging lens and a portion of a guide laser beam reflected from the converging lens. The light collection system includes a dichroic optical device configured to optically separate the portions.

Abstract: A tilt control method for a near-field optical disc drive is provided. A gap between a lens and a disc is estimated. A tilt compensation for the lens is estimated according to a tilt signal when the lens is within a far-field region. A coarse tilt control is performed on the lens according to the tilt compensation when the lens is within the far-field region.

Abstract: A rotary position encoder for determining a rotary position of a shaft includes a rigid substrate having a planar surface and mounted on the shaft to rotate with the shaft; an optical disk having at least a transparent polycarbonate layer and a reflective layer on the transparent polycarbonate layer, affixed to the planar surface of the substrate, the optical disk having a first circumferential track encoded therein having binary data; an optics assembly for interrogating the optical disk and providing an output signal indicative of data received from the interrogation of the optical disk; and a tracking motor for driving the optics assembly radially with respect to the optical disk.

Abstract: An optical pickup, photodetector, and optical drive adopting the optical pickup are provided. The optical pickup may include a light emitting system having a plurality of light sources corresponding to a plurality of mediums a light receiving system including a photodetector for converting light reflected from a medium into an electrical signal. The photodetector may include first and second light receiving sensors corresponding to the plurality of mediums, each of the first and second light receiving sensors comprising a plurality of regions, each region comprising a plurality of sectors. The plurality of regions of the first and second light receiving sensors may include shared sectors that are shared by the first and second light receiving sensors and exclusive sectors that are exclusively used in the first light receiving sensor or the second light receiving sensor.

Abstract: Disclosed herein are aspects of optical tape technology, tape manufacturing, and tape usage.

Abstract: An optical disk drive (ODD) is provided. The ODD includes an optical pickup unit; and at least one pickup guide for contacting with at least one guide that guides a motion of the pickup unit, wherein the pickup guide includes at least one oil housing unit for housing oil applied to the guide. The oil housing unit is provided in a quadrangular or triangular groove shape toward a portion contacting with the guide in the pickup guide. Further, the oil housing unit is formed at both sides of the pickup guide in a length direction of the guide, or when two pickup guides are coupled to at least one guide, the oil housing unit is formed only at a far position from the other pickup guide in each of the two pickup guides. Therefore, a contamination phenomenon of an optical pickup unit due to scattering of oil can be reduced.

Abstract: An optical disc apparatus in which a bias of a focusing error signal is changed to a value according to a recording power at timing corresponding to a predetermined address position before starting the recording and a defocus of an opposite polarity is preliminarily caused so as to set off a defocus which occurs at the start of the recording.

Abstract: A recording apparatus for performing information recording using formation of marks by focusing a first light with an objective lens at a given position in a recording layer included in an optical disc recording medium, includes: a rotation driving unit for rotating the optical disc recording medium; a focus servo control unit for condensing a second light which is different from the first light on a reflection film, and for controlling a position of the objective lens so that a focal position of the second light follows the reflection film; a recording position setting unit for setting an information recording position of the first light in a focus direction by changing the collimation of the first light; a surface wobbling amount estimating unit; and a surface wobbling estimation amount acquisition control unit for acquiring a surface wobbling estimation amount for each rotation angle within one revolution of the disc.

Abstract: A recording apparatus for performing information recording using formation of marks by focusing a first light with an objective lens at a given position in a recording layer included in an optical disc recording medium, includes: a rotation driving unit; a focus servo control unit for condensing a second light on a reflection film and for controlling a position of the objective lens; a recording position setting unit for setting an information recording position of the first light in a focus direction; a tracking servo control unit for controlling a position of the objective lens; an eccentricity amount estimating unit for estimating an eccentricity amount of the optical disc recording medium; and an eccentricity estimation amount acquisition control unit for acquiring an eccentricity estimation amount for each rotation angle within one revolution of the disc.

Abstract: A vertical cavity surface emitting laser that includes: a substrate; a first semiconductor multilayer reflector; an active region; a second semiconductor multilayer reflector; a columnar structure formed from the second semiconductor multilayer reflector to the first semiconductor multilayer reflector; a current narrowing layer formed inside of the columnar structure and having a conductive region surrounded by an oxidization region; a first electrode formed at a top of the columnar structure, electrically connected to the second semiconductor multilayer reflector and defining a beam window; a first insulating film comprised of a material with a first refractive index and formed on the first electrode to cover the beam window; and a second insulating film comprised of a material with a second refractive index and formed on the first insulating film, of which a radius is smaller than a radius of the conductive region.

Abstract: A tilt adjustment control method for a near-field optical system is provided. The method includes the following steps. A gap between a lens and a disc is detected. A gain corresponding to the gap is provided. A tilt signal is detected. A tilt compensation value according to the tilt signal and the gain is obtained. A tilt adjustment control is performed on the lens according to the tilt compensation value.

Abstract: In an optical disk including at least a rewritable phase change material and comprising a recording layer having a reflectivity of more than 15%, an address output value as an address pit signal component occupying in a reproduced signal in a non recording state is prescribed to be 0.18 though 0.27 or a numerical aperture of an address pit signal occupying in a reproduced signal in a non recording state is prescribed to be more than 0.3.

Abstract: Provided is an optical device configured to makes it possible to enhance use efficiency of light. An optical device is provided with an optical element to deflect incident light and a fixation member on which the optical element is fixed. The optical element includes a reflective surface and a diffraction grating surface that deflects the incident light. The optical element is fixed on the fixation member to restrain displacement in accordance with temperature changes at portions thereof other than the reflective surface and the diffracting grating surface in such a condition that displacement is caused without restraint be temperature changes at the reflective surface and the diffraction grating surface. A change of the incident light in the deflection angle due to an inclination change by the reflective surface and the diffracting grating surface is suppressed by a change in a diffraction angle due to a periodical change in the diffraction grating by the displacement of the diffraction grating surface.

Abstract: A pickup apparatus includes a light source; a light separator; an object lens that concentrates the light which penetrated the light separator on the optical recording medium; a movable lens; and a light sensing element that receives the reflected light from the optical recording medium separated by the light separator, wherein a coma aberration generated by the transverse shift of the object lens is corrected by a coma aberration which is generated by the deviation of a spherical aberration generated in an optical path from the light source to the object lens and a spherical aberration generated in an optical path from the object lens to a light concentration position on the optical recording medium which are due to the transverse shift.

Abstract: An optical head device and an optical disc apparatus of a simple structure capable of canceling an offset in a tracking error signal caused when an objective lens shifts; in the optical head device, a polarizing hologram 104 has first diffraction areas 112 and 113 including a whole of an area irradiated with overlap of a zeroth-order beam of reflection light from an optical disc 1 and positive/negative first-order beams of the reflection light, and a second diffraction area 111 including an area irradiated with the zeroth-order beam of the reflection light and not irradiated with the positive/negative first-order beams of the reflection light without including the first diffraction area; and a photodetector 109 has a first light receiving section 131 for receiving a first light beam which is a zeroth-order beam of diffraction light generated by the polarizing hologram 104, a second light receiving section for receiving a second light beam which is a positive first-order beam of the diffraction light generated

Abstract: An objective optical system for an optical information recording/reproducing apparatus for recording/reproducing for first, second and third optical discs by selectively using three types of substantially collimated light beams including first, second and third light beams respectively having first, second and third wavelengths, wherein at least one of optical surfaces of the objective optical system comprises a diffraction surface having a diffraction structure, the diffraction surface includes a first region defined by first and second optical path difference functions, a second region defined by at least one type of optical path difference function, and a third region defined by at least one type of optical path difference function, the first region satisfies a condition: ?0.15<f1/fD11<?0.03??(1), where fD11=?1/(2×P112×m11×?), and the diffraction surface satisfies a condition: ?0.05<(?13(h3)??13(h2))/(m13×f1)<?0.005??(2).

Abstract: An information recording medium is at least composed of a substrate having a microscopic pattern constituted by a continuous substrate of grooves formed with a groove portion and a land portion alternately, a recording layer formed on the microscopic pattern for recording information, and a light transmitting layer formed on the recording layer. The microscopic pattern is formed with satisfying a relation of P??/NA, wherein P is a pitch of the land portion or the groove portion, ? is a wavelength of reproducing light for reproducing the recording layer, and NA is a numerical aperture of an objective lens. The land portion is formed with wobbling so as to be parallel with each other for both sidewalls of the land portion. An auxiliary information based on data used supplementally when recording the information and a reference clock based on a clock used for controlling a recording speed when recording the information is recorded alternately.

Abstract: In a servo controller and an optical disk device (FIG. 4), the following performance for disturbance is improved. By disposing a characteristic change section to change a characteristic to improve the following performance for disturbance, the disturbance is detected by use of a signal in a stage after the characteristic change section.

Abstract: A recording power determination method for determining a recording power of an optical beam for recording data on an information storage medium includes the steps of recording test data on the information storage medium at a plurality of test recording powers; reading the test data recorded at each test recording power, generating a signal, and measuring a modulation factor of the signal corresponding to each test recording power; calculating a product of an n'th power of each test recording power and the corresponding modulation factor, thereby obtaining a plurality of products corresponding to the plurality of test recording powers, where n is a value of exponent and is a real number other than 1; calculating a first recording power based on the correlation between the plurality of test recording powers and the plurality of products; and calculating the recording power based on the first recording power.

Abstract: An optical pickup apparatus includes: a laser diode configured to emit a laser beam; and an objective lens configured to condense the laser beam into a laser spot through which a signal recorded on a signal recording layer of an optical disc is read out by the laser beam, the objective lens having formed thereon a lens surface with a second numerical aperture for acting as a lens, which is larger than a first numerical aperture for forming the laser spot.

Abstract: A method for compensating the coma aberration in a pickup of a recording and reproducing device that records or reproduces data on or from an optical disc using the pickup is provided. The method includes a first coma aberration compensating step to compensate coma aberration in a body of an optical system including an objective lens for emitting a light beam to an optical disc including a plurality of recording layers and a second coma aberration compensating step to compensate coma aberration caused by relative inclination of the optical system with respect to the optical disc.

Abstract: If a defective cluster in a spare area is managed with a defect entry, the size of a DFL will increase as the size of the spare area increases with an increase in the number of recording layers stacked in a disc. An information recording medium according to the present invention has pointer information indicating the location of the next available cluster in each spare area, and restricts the direction in which the spare area is used. Also, a defect entry indicating a defective cluster in the spare area is registered with the DFL. Thus, even if the size of the spare area 15 increases, the size of the DFL 21 can be kept relatively small. Furthermore, even after physical reformatting is done, a defective cluster, if any, in the spare area 15 can still be recognized as a defect and the control operation can be performed so that a replacement cluster is not re-allocated to that defective cluster (i.e., the defective cluster is not used).

Abstract: In a laser welding method, detachment is suppressed and dislocation of an optical component is reduced by improving adhesiveness of an interface of a welded part to thereby improve yield and reliability of an optical pickup device. A manufacturing method of an optical pickup device includes: a step of bringing the optical component into contact with the holding member; a step of irradiating laser light; and a step of melting the holding member through the irradiation to weld the holding member to the optical component, wherein before the laser light is irradiated, surface roughness of a portion of the optical component to be welded is greater than surface roughness of the holding member in contact with the portion, whereby the melted holding member enters into an uneven part on a front surface of the optical component, improving adhesion strength.

Abstract: An optical unit includes an optical system for shining a laser beam on an optical recording medium having a recording layer and a focus control reference surface. The optical system is composed of an objective lens for focusing a recording/reproducing beam emitting from a first light source in the recording layer and focusing a focus control beam emitted from a second light source on the focus control reference surface, a first lens system disposed along an optical path of the recording/reproducing beam and capable of discretely varying a focus position of the recording/reproducing beam in a direction of a thickness of the recording layer, and a second lens system disposed along an optical path common to the recording/reproducing beam and the focus control beam and capable of continuously varying focus positions of the recording/reproducing beam and the focus control beam in a direction of a thickness of the recording layer.

Abstract: The invention provides an apparatus for controlling servo signal gains of an optical disc drive. The apparatus adjusts the gains of a plurality of servo signals controlling a servo system of the optical disc drive when the optical disk drive encounters an operating state transition. In a first mode, at least one AGC loop of the apparatus compensates the gains of the servo signals with a selectable bandwidth during a specific period after the operating state transition to accelerate the convergence of the servo signals. In a second mode, at least one AGC loop of the apparatus reloads the previously saved convergence values or pre-determined values as the initial values according to the current operating state immediately after the operating state transition to accelerate the convergence of the servo signals.

Abstract: An objective lens is made of a resin material and focuses incident rays, which have a wavelength of 410 nm or less and are emitted from a light source, on an optical disc at a numerical aperture of 0.8 or more, wherein when a lens tilt sensitivity is defined as an amount of a 3rd-order coma aberration caused per a lens tilt of 1 degree which is an angle formed between an optical axis of the objective lens and a system optical axis of an optical system including the objective lens at 0° C., the lens tilt sensitivity is 130 m?rms/degree or less.

Abstract: A pickup and a drive, in a small size, having a spherical aberration correction device capable of correcting various spherical aberration, and coma aberration and/or astigmatism with a low power consumption. A variable-focus lens actuator can correct spherical aberration such that a transparent deformation film warps into a parabolic shape when a magnetic field is applied thereto, thereby changing the light intensity distribution of transmitted light. Further, the variable-focus lens actuator can correct coma aberration and/or astigmatism by arbitrarily tilting the transparent film to change the proceeding direction of the transmitted light.

Abstract: An optical pickup apparatus comprises: a first laser diode that generates a first laser beam having a first wavelength; a second laser diode that generates a second laser beam having a second wavelength longer than the wavelength; a third laser diode that generates a third laser beam having a third wavelength longer than the first wavelength and shorter than the second wavelength; an objective lens having an inner, outer, intermediate regions on an incident surface, the first laser beam being condensed on a signal recording layer of a first optical disc by condensing actions of the inner and outer regions, the second laser beam being condensed on a signal recording layer of a second optical disc by condensing actions of the inner and intermediate regions, the third laser beam being condensed on a signal recording layer of a third optical disc by condensing actions of the inner and intermediate regions.

Abstract: An optical information media, system, and method for providing ubiquitous reading and selective writing is disclosed. By placing data structures representing a nonstandard book type in byte “0” of the media, the media is made universally bootable and universally readable in substantially any DVD drive. On the other hand, data structure representing a version code or disc category is placed in byte “0” or another byte of the control data zone in order to identify the media and enable writing in select drives. The version code and/or disc category identifies the media and calls for one or more write strategies configured for writing to the particular media. When the media is a permanent storage media, loss of data can be avoided, ubiquitous read can be achieved, and selective write in predetermined drives can be achieved resulting in a robust system and method of storing and retrieving data.

Abstract: Methods and systems are described for assessing the results of a bioassay between probe biomolecules and target biomolecules using a conventional optical disc drive.

Abstract: Compatibility information embedded in an optical medium modifies actions allowed by predetermined non-compatible optical disc drives on the optical medium, such as optical disc drives that may suffer damage if certain actions are performed on the optical medium. For instance, a compatibility engine of the optical disc drive applies compatibility information read from an optical medium to determine restrictions to impose on the use of the optical medium, such as restricting the optical disc drive from writing to the optical medium, reading from the optical medium or performing any operations until an update to the optical disc drive firmware is performed either automatically or by display of a compatibility user interface at an information handling system associated with the optical disc drive. In one embodiment, the compatibility information identifies incompatible optical disc drives and firmware versions by unique identifiers.

Abstract: A half-wave plate includes a single crystal plate made of an inorganic material having a birefringent property and rotatory power, wherein a polarization plane of linearly polarized light entering from an entrance surface of the crystal plate is rotated and then output from an exit surface of the crystal plate.