Abstract: The present invention can properly correct spherical aberration. An optical disk device (10) displaces an objective lens (18) so that the objective lens is displaced to a reference lens position as a reference. The optical disk device (10) controls an information light condensing point changing mechanism (55) so as to adjust the focus (FM) of an information light beam (LM) to a recording depth (X) at which the information light beam (LM) is to be applied in a state of the objective lens (18) being placed at a reference lens position (SL). The optical disk device (10) controls a servo light condensing point changing mechanism (35) so as to adjust the focus (FS) of a servo light beam (LS) to a servo layer (104) in the state of the objective lens (18) being placed at the reference lens position (SL).

Abstract: According to one embodiment, an information storage medium in which layer 0 and layer 1 are arranged from a read surface, a system lead-in area, data lead-in area, data area, and middle area are arranged from an inner circumference of the layer 0, and a system lead-out area, data lead-out area, data area, and middle area are arranged from an inner circumference of the layer 1. A guard track zone is arranged on a side of the data area in the data lead-out area, and a reference code zone, R physical format information zone, recording management zone, and drive test zone are arranged in the data lead-in area of the layer 0 and padding of the guard track zone of the data lead-out area is performed after padding of the drive test zone of data lead-in area and recording of the recording management zone.

Abstract: Provided is an information storage medium that has a plurality of recording layers, a recording/reproducing method, and a recording/reproducing apparatus. In the information storage medium, each of the plurality of recording layers includes an inner circumference zone and a data zone, and at least one of the recording layers includes, in the inner circumference zone, a temporary disc management area (TDMA) for recording information about a defect detected in the data zone, wherein a size of a TDMA allocated on an upper layer is greater than a size of a TDMA allocated on a lower layer.

Abstract: Obtain an expanded address without altering the bit number of an address which is embedded in a wobble. Generate a virtual bit which is not recorded on a disc, and which is expressed by the disparity from the rules and the presence or absence of information embedded in part or all of the wobble address.

Abstract: Information is recorded on a multi-layered optical recording medium by irradiating it with a laser beam. The recording medium can form a first information recording layer that is the farthest from a light incident surface, a second information recording layer that is the second farthest from the light incident surface, and at least one third information recording layer that is located closer to the light incident surface than the second information recording layer is. At this time, if all the information recording layers other than the first information recording layer are either blank or have been completely recorded, then information is recorded on the first information recording layer. This allows for stabilizing the energy of a recording laser beam during recording and thereby providing improved recording quality.

Abstract: An object of the present invention is to increase the number of stacked layers in a multilayer optical recording medium while simplifying the design of the multilayer optical recording medium is provided a multilayer optical recording medium including at least four recording and reading layers from which information can be reproduced by light irradiation, the layers stacked through intermediate layers. The multilayer optical recording medium includes a plurality of recording and reading layers that are continuous in order of stacking and includes at least one recording and reading layer group in which reflectance in a stacked state decreases from a near side of a light incident surface to a far side. A single-layer reflectance of the nearest recording and reading layer is set to 0.2% or more and less than 2.0%, and a light transmittance improvement process is applied to the light incident surface.

Abstract: According to one embodiment, an information storage medium in which layer 0 and layer 1 are arranged from a read surface, a system lead-in area, data lead-in area, data area, and middle area are arranged from an inner circumference of the layer 0, and a system lead-out area, data lead-out area, data area, and middle area are arranged from an inner circumference of the layer 1. A guard track zone is arranged on a side of the data area in the data lead-out area, and a reference code zone, R physical format information zone, recording management zone, and drive test zone are arranged in the data lead-in area of the layer 0 and padding of the guard track zone of the data lead-out area is performed after padding of the drive test zone of data lead-in area and recording of the recording management zone.

Abstract: There are provided an optical head and an optical information device capable of downsizing the optical head, and capable of improving the qualities of a focus error signal, a tracking error signal, and a reproduction signal. A light detector (120) includes a light-receiving unit (121) for receiving a reflected light beam from an optical disc, and a package (125) for covering the light-receiving unit (121). The package (125) has a plurality of light guides (124) formed on a light-receiving surface on the light beam incident side of the light-receiving unit (121), and for guiding a reflected light beam to the light-receiving unit (121), and a light shield (114) for shielding a region except for a plurality of the light guides (124) from light.

Abstract: An optical recording medium is provided. The optical recording medium includes a multilayer including an N (N?5) number of interfaces capable of reflecting incident light.

Abstract: An optical head 12 reproduces information recorded on an optical disc 11, a BCA detector 21 and a medium discriminating circuit 22 acquire waveform distortion information for specifying a waveform distortion of a reproduction signal reproduced by the optical head 12, and a variable waveform equalizer 16 changes a parameter used in a distortion reduction processing for reducing the waveform distortion of the reproduction signal based on the waveform distortion information.

Abstract: An optical recording medium includes: N recording layers (where N?4); a number of kinds of layer intervals between the recording layers adjacent to each other being an integer M equal to or less than a minimum integer equal to or more than log2(N); and one or more AB blocks including four recording layers with a first layer interval A, a second layer interval B, and the first layer interval A formed in order in the one or more AB blocks. When the M as the number of kinds of layer intervals is M?3, the optical recording medium has a part of a third layer interval C as a layer interval between a recording layer forming an AB block and a recording layer adjacent to the recording layer, the adjacent recording layer being included in other than the AB block including the recording layer.

Abstract: An optical information recording medium includes at least one recording layer, a protective layer that transmits a focused laser beam, and a super-resolution functional layer that changes an optical characteristic in a local region smaller than the diffraction limit determined by the optical performance of the focusing optical system and the wavelength of the laser beam during at least the period of irradiation by the focused laser beam. The maximum thickness (K) between the light incidence surface of the protective layer and the recording layer is 0.083 mm.

Abstract: Erroneous data erasure owing to radiation of laser beam with excessive power to the recording layer of the multilayered optical disc upon servo-off while reproducing data of the disc is prevented. When detecting the servo-off based on the amplitude of the tracking error signal or the focus error signal, the laser beam power is reduced to a predetermined minimum value, and the laser beam power value is set again based on the address of the recording medium, which has been obtained later for reproduction. The laser beam power value is changed by applying an offset to the drive current or changing the target value under APC.

Abstract: An optical system for optical pickup includes a magnification conversion optical element moving along an optical axis direction in accordance with each of optical recording medium recording surfaces, and an objective lens element converging a light beam incident through the magnification conversion optical element, to form a spot on a corresponding one of the recording surfaces, and satisfies the following formula: 4.0×10?4<Mn/(tn?tc)×f<6.0×10?4. Here tc is the thickness [?m] of a recording-medium base material at which a third-order spherical aberration occurring when a parallel light beam is incident on the objective lens element is the minimum, f is the focal length [mm] of the objective lens element, and Mn is the imaging magnification of the objective lens element when a spot is formed through a thickness tn [?m]of the base plate.

Abstract: An optical information recording medium 10 comprises a plurality of recording layers 14 and intermediate layers 15 each provided between the recording layers 14. Each of the recording layers 14 includes a polymer binder and dye dispersed in the polymer binder, and a thickness of each recording layer is equal to or greater than 50 nm. A first interface (near-side interface 18) is formed between a recording layer 14 and an intermediate layer 15 that is adjacent to the recording layer 14 on one side of the recording layer 14 in a thickness direction of the recording layer 14, and a second interface (far-side interface 19) is formed between the recording layer 14 and an intermediate layer 15 that is adjacent to the recording layer 14 on the other side of the recording layer 14 in the thickness direction of the recording layer 14.

Abstract: According to one embodiment, an information storage medium in which layer 0 and layer 1 are arranged from a read surface, a system lead-in area, data lead-in area, data area, and middle area are arranged from an inner circumference of the layer 0, and a system lead-out area, data lead-out area, data area, and middle area are arranged from an inner circumference of the layer 1. A guard track zone is arranged on a side of the data area in the data lead-out area, and a reference code zone, R physical format information zone, recording management zone, and drive test zone are arranged in the data lead-in area of the layer 0 and padding of the guard track zone of the data lead-out area is performed after padding of the drive test zone of data lead-in area and recording of the recording management zone.

Abstract: Optical information recording medium comprises: a plurality of recording layers 14, each of which undergoes a change in refractive index by irradiation with recording beam; and an intermediate layer 15 provided between recording layers 14. The recording layer 14 contains polymer binder and dye dispersed in the polymer binder, and at least in proximity to an interface (far-side interface 18) between the intermediate layer 15 and a recording layer 14 disposed adjacent to incident side of the intermediate layer 15 from which the recording beam enters the intermediate layer, the intermediate layer 15 has refractive index different from that of the recording layer 14. Glass transition temperature of the polymer binder is lower than melting point and decomposition point of the dye, and refractive index of the polymer binder changes by receiving heat generated when the dye absorbs the recording beam, whereby information is recordable in the recording layer.

Abstract: A multilayer optical recording medium includes a plurality of interfacial surfaces that reflect an incident light beam, and neighboring ones of the interfacial surfaces has a spacer therebetween. When a light incident surface side is defined as an upper surface side, a different thickness layer unit including the spacers having different thicknesses arranged sequentially is disposed on the lowermost layer side, and the spacers each having a thickness different from the thickness of any one of the spacers arranged in the different thickness layer unit are sequentially arranged above the different thickness layer unit.

Abstract: Shape-wise thicknesses of a cover layer and first through (N?1)th intermediate layers of an optical recording medium having refractive indexes nr1, nr2 are converted into thicknesses t1, t2 of the respective layers having a predetermined refractive index which makes a divergent amount equal to a divergent amount of a light beam resulting from the thicknesses tr1, tr2, a difference DFF between the sum of a thickness “ti” through a thickness “tj”, and the sum of a thickness “tk” through a thickness “tm” is set to 1 ?m or more (where i, j, k, and m are each any positive integer satisfying i?j<k?m?N), and the thicknesses t1, t2 are calculated by products of a function f(n) expressed by the following formula (1), and the thicknesses tr1, tr2: f(n)=?1.088n3+6.1027n2?12.042n+9.1007??(1) in the formula (1), n=nr1, nr2, . . . , and nrN.

Abstract: An optical pick-up apparatus for reproducing information recorded on an optical recording medium or recording information on the optical recording medium is provided. The optical pick-up apparatus includes a light source unit which generates beams; a diffraction element which diffracts the generated beams; and an objective lens which focuses a p order diffracted beam which is used for recording and reproducing information among a plurality of diffracted beams which are diffracted by the diffraction element on any one of a plurality of information layers which are formed on an optical recording medium. A p±1 order diffracted beam which is not used for recording and reproducing information is focused away from the plurality of information recording layers and on the surface of the optical recording medium.

Abstract: In a multilayer optical recording medium, it is an object to suppress generation of crosstalk while reducing an interlayer distance of recording and reading layers. In an optical recording medium including three or more recording and reading layers, a first distance, and a second distance greater than the first distance by 3 ?m or more are alternately defined as interlayer distances of recording and reading layers.

Abstract: A recording device including a light irradiating and light receiving unit which, in regard to an optical recording medium, which has a reference surface and a recording layer which is formed at a depth position different from the reference surface, where a pit row where intervals of pit formable positions in one circumference is limited to a first interval is formed in the reference surface, and which has a plurality of pit row phases by intervals of the pit formable positions in a pit row formation direction being set in a position which is each deviated by a predetermined second interval in the pit row which are arranged in the radial direction, irradiates a first light as recording light with regard to the recording layer and a second light for obtaining reflected light from the reference surface and which receives reflected light of the second light from the reference surface.

Abstract: A multilayer optical disc which has three or more recording layers and enables easy positioning of a focused beam spot onto a particular recording layer in which a BCA is disposed. An inter-layer distance between a particular recording layer and a recording layer adjacent to the particular recording layer is larger than the other inter-layer distances in which, at the focused beam spot positioning, the focused beam spot traverses the said adjacent recording layer earlier than the other recording layer adjacent to the particular recording layer.

Abstract: A recording wavelength generator selects control parameters of a recording pulse sequence, based on combinations of mark length, a first space length of a first space immediately before the mark, and a second space length of a second space immediately after the mark. A laser drive circuit records the marks by the recording pulse sequence. The first and second space lengths are classified into m and n types, respectively. An absolute value of a difference between two predetermined control parameters from among (m×n) control parameters selected during recording on a second information layer located on an incidence side of the laser beam with respect to a predetermined first information layer from among N information layers is equal to or greater than an absolute value of a difference between two predetermined control parameters from among the (m×n) control parameters selected during recording on the first information layer.

Abstract: Provided is a recording apparatus including a light irradiation and receiving unit configured to irradiate recording light for performing mark recording to a recording layer and an adjacent servo light for an adjacent track servo onto an optical disc recording medium having the recording layer through a common objective lens, and to receive reflected light from the recording layer of the adjacent servo light, a tracking mechanism configured to drive the objective lens in a tracking direction which is the disc radial direction, a tracking servo signal generation unit configured to obtain a corrected servo error signal as a servo error signal based on a light receiving signal for the adjacent servo light, and to generate a tracking servo signal using the corrected servo error signal, and a tracking driving unit configured to drive the tracking mechanism based on the tracking servo signal.

Abstract: An optical disc device and a recording method is provided in which information can be additionally recorded on an optical disc, which has a servo layer and recording layers separately formed, by accurately correcting a relative angle between a light beam and the optical disc used in the previous recording without providing an area where recording is not performed while maintaining the stability of tracking servo. The above subject can be solved by studying with high accuracy the relative angle between the optical disc and the optical axis used in the previous recording by applying a radial tilt servo according to a signal from the recording layers with the tracking servo applied by the servo layer. Further, the additional recording can be performed stably by fixing the radial tilt at the previously studied angle when the recording is performed.

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: In an optical disk having multiple layers for which a correction of spherical aberration is required, a spherical aberration correcting element is set to a predetermined spherical aberration correction amount; a laser light source is turned ON; an objective lens is swept; when it is discriminated that the optical disk has two or more layers, or has more than two information recording planes, the spherical aberration correction amount is changed into a spherical aberration correction amount suitable for information recording planes of three, or more layers; and the objective lens is again swept so as to discriminate a total layer number thereof.

Abstract: An information storage medium having a plurality of recording layers is provided. The information storage medium including a physical ADIP address (PAA) which corresponds to an address recorded on the information storage medium. In the case in which an address of a layer i to which a pickup will move corresponds to PAAi, an address of a layer j in which the pickup is currently located corresponds to PAAj, and n corresponds to the number of the recording layers, the PAAi and the PAAj satisfy the equation PAAi= PAAj+(7?(i+j))*40 00 00h+00 00 01h(i+j=odd and i,j=0,1,2, . . . ,n?1) in response to the pickup moving from an even layer to an odd layer or from an odd layer to an even layer, and satisfy the equation PAAi=PAAj+(i?j)*40 00 00h(i+j=even and i,j=0,1,2, . . . ,n?1) in response to the pickup moving from an even layer to another even layer or from an odd layer to another odd layer.

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: An optical pickup device including: a laser diode for emitting laser light; an objective lens which irradiates an optical beam emitted from the laser diode; an actuator which displaces the objective lens in a radius direction of the optical disc; a grating for branches an optical beam reflected by an information recording layer into plural regions; and one photodetector having plural light receiving parts for receiving the branched optical beams, wherein the photodetector has a first light receiving part which detects zero-th order grating diffracted light and plural second light receiving parts which detecting grating diffracted light having an order not less than that of ±first order grating diffracted light; a detected signal of the zero-th order grating diffracted light is defined as a reproduction signal; and a detected signal of the grating diffracted light is defined as a signal for servo controlling.

Abstract: An optical head device includes a light blocking region disposed on a light flux of a reflected light beam resulting from reflection by a recording layer on which a blue light beam is focused, and blocks, when there are at least two recording layers on a blue light beam incident side of the recording layer on which the blue light beam is focused or on a side thereof opposite to the blue light beam incident side, reflected light beams resulting from reflection by the at least two recording layers which are incident on a region in a photodetector where the reflected light beams resulting from the reflection by the at least two recording layers interfere with each other. The light blocking region is not formed on an optical axis of the reflected light beam resulting from the reflection by the recording layer on which the blue light beam is focused.

Abstract: A multilayer optical disc which has three or more recording layers and enables easy positioning of a focused beam spot onto a particular recording layer in which a BCA is disposed. An inter-layer distance between a particular recording layer and a recording layer adjacent to the particular recording layer is larger than the other inter-layer distances in which, at the focused beam spot positioning, the focused beam spot traverses the said adjacent recording layer earlier than the other recording layer adjacent to the particular recording layer.

Abstract: The present invention relates to a recording apparatus, record carrier and method of recording data on at least two layers of a recording medium by using a radiation power, wherein individual recording speeds are determined for respective ones of the at least two layers at different values of the radiation power. A recording speed to be used for recording on an individual one of the at least two recording layers is selected based on a maximum radiation power specified for the recording operation, and the speed of the recording operation is controlled individually for each of the at least two layers based on the selected recording speed. The determination of the individual recording speeds at different radiation power values may be written or embossed on the record carrier. Furthermore, a recording sequence used for recording on the recording layers can be set based on the sensitivities and thus recording speeds. Thereby, total recording time can be minimized for multi-layer recording media.

Abstract: An optical pickup has an objective lens that is shared for light of three wavelengths. The effective diameter of the light that passes through the objective lens decreases in a sequence of the light of a first wavelength (light for a first optical disk), the light of a second wavelength (light for a second optical disk) and the light of a third wavelength (light for a third optical disk); and the light of the third wavelength is incident on the objective lens in a finite system. The objective lens is provided so that the focal distance of the light of the second wavelength is greater than the focal distance of the light of the first wavelength.

Abstract: The present invention relates to a recordable optical record carrier for recording information using a radiation beam having wavelength ? and incident on an entrance surface of the optical record carrier comprising, in this order: a protective layer facing the entrance surface; first recording stack (L0), the recording stack comprising a recording layer of an organic dye material and a groove structure; a transparent spacer layer sandwiched between the neighboring recording stacks; and a second recording stack (LN) comprising a recording layer, wherein the groove depth of the recording layer of the first recording stack (L0) is in a range from 0.241*?/nS to 0.362*?/nS, where nS is a refractive index of a material in a land between grooves on the groove structure.

Abstract: First and second A/D converters perform analog/digital conversion of first and second signals of a Hall signal so as to generate third and fourth signals as digital signals. A differential conversion circuit generates a fifth signal as a single-ended signal that corresponds to the difference between the third and fourth signals. An offset correction circuit corrects offset of the fifth signal so as to generate a sixth signal. An amplitude control circuit stabilizes the amplitude of the sixth signal to a predetermined target value, and generates its absolute value, thus generating a seventh signal. A control signal generating unit generates a control signal based upon the seventh signal. A driver circuit drives a motor according to the control signal.

Abstract: When performing recording/reproduction of information for a given recording layer of an optical disc having three recording layers, influences of reflected light from other recording layers are reduced or removed, thus making it possible to obtain a more stable RF signal or focus error signal. An optical pickup device includes a light source, a collimator lens, an objective lens, a photodetector, and a light shielding member. Among the recording layers of the optical disc, a first layer and a second layer adjoining each other are disposed in the order of the first layer and second layer from near the objective lens.

Abstract: Shape-wise thicknesses of a cover layer and first through (N?1)th intermediate layers of an optical recording medium having refractive indexes nr1, nr2 are converted into thicknesses t1, t2 of the respective layers having a predetermined refractive index which makes a divergent amount equal to a divergent amount of a light beam resulting from the thicknesses tr1, tr2, a difference DFF between the sum of a thickness “ti” through a thickness “tj”, and the sum of a thickness “tk” through a thickness “tm” is set to 1 ?m or more (where i, j, k, and m are each any positive integer satisfying i?j<k?m?N), and the thicknesses t1, t2 are calculated by products of a function f(n) expressed by the following formula (1), and the thicknesses tr1, tr2: f(n)=?1.088n3+6.1027n2?12.042n+9.1007??(1) in the formula (1), n=nr1, nr2, . . . , and nrN.

Abstract: A disc-shaped information recording medium includes a laminate of recording layers on and from which an information signal can be optically recorded and reproduced from one side of the medium. Data areas are provided in the recording layers, respectively. The information signal can be recorded on and reproduced from the data areas while a laser beam emitted from an optical pickup is applied to the data areas. Optical recording test areas are provided in the recording layers, respectively. A test signal can be recorded on and reproduced from the optical recording test areas to decide optimum power values of the laser beam for signal recording. The test areas are out of overlap as viewed in a direction of propagation of the laser beam.

Abstract: An information recording medium (100) of the present invention has a plurality of recording layers (110, 120, 130, and 140) for recording therein data. Each of the plurality of recording layers corresponds to one of a plurality of recording formats. A first recording layer number (SLN) assigned with each of the recording layers in accordance with a disposed position of each of the recording layer and a second recording layer number (LLN) assigned with corresponding recording format are included in the address area (14) for the data, with respect to each of the plurality of recording layer.

Abstract: An optical pickup, an optical disk drive device, an optical information recording device, and an optical information reproduction device in which a reproduction signal, a focus error signal, and a gap error signal can be detected with high accuracy when information is recorded/reproduced on/from an optical information medium having a plurality of information recording layers.

Abstract: An optical information recording medium (100) of the present invention includes an information layer (011) that allows information to be recorded thereon and reproduced therefrom by irradiation with a laser beam (040). The information layer (011) includes a reflective layer (002), a first dielectric layer (003), a recording layer (005) capable of undergoing a phase change by the irradiation with the laser beam (040) and a second dielectric layer (007) formed in this order from a side opposite to a laser beam incident side. The recording layer (005) contains Ge, Sb and Te. When Ge, Sb and Te contained in the recording layer (005) are represented by GexSbyTez in atomic number ratio, x, y, and z satisfy 0.39?x?0.48, 0.02?y<0.11, 0.40?z<0.56, and x+y+z=1. The recording layer (005) has a thickness of at least 10 nm but not more than 15 nm.

Abstract: An optical recording/reproduction method and device that can perform control for optimizing the amount of spherical aberration in a multilayered optical disc in a short period of time. When the objective lens is displaced in the focusing direction, the amplitude value of the focusing error signal detected just after leaving the focal position of a given first recording layer and the amplitude value of the focusing error signal detected just before passing through the focal position of a given second recording layer other than the first recording layer are measured with a particular spherical aberration, the amplitude ratio of amplitude values is calculated, the difference between spherical aberration and the optimal spherical aberration for the second recording layer is approximated as a function of the amplitude ratio, the optimal spherical aberration is calculated on the basis of this approximation, and the spherical aberration is set.

Abstract: Provided are an optical disc having a plurality of recording layers, and a method and apparatus for recording data thereon. The optical disc has a plurality of recording layers, each recording layer including: a data area; a connecting area; and a remaining area. The data, connecting, and remaining areas are respectively disposed in a direction from an inner circumference of the optical disc to an outer circumference. An outer boundary of each of the data areas is determined according to an amount of data to be recorded. Locations of the connecting areas and the remaining areas are determined by a recording and/or reproducing apparatus according to the determination of the outer boundary of each of the data areas.

Abstract: Efficient recording and reading are achieved in an optical recording medium including servo layers and recording and reading layers. The optical recording medium includes: a first servo layer having a projection and a depression for tracking control that are formed in a first spiral direction; a second servo layer having a projection and a depression for tracking control that are formed in a second spiral direction opposite to the first spiral direction; and a plurality of recording and reading layers having a flat structure with no projection and depression for tracking control. Information is recorded on each of the plurality of recording and reading layers while tracking control is performed using the first servo layer or the second servo layer.

Abstract: The present invention provides a method and an apparatus for determining the number of data layers in an optical disc. Firstly, the objective lens of the optical pickup head is controlled so that it moves toward the optical disc. At the same time, a generated SBAD signal is recorded. The number of wave peaks in the SBAD signal is then detected and the number of the data layers in an optical disc is determined according to the detected number of wave peaks in the SBAD signal.

Abstract: A method comprising recording data related to a start-up procedure on at least one of a plurality of recording layers disposed on an optical record carrier for reading back the recorded data during subsequent start-ups, the selection of the at least one recording layer based on properties of the at least one recording layer is disclosed. The technique reduces the optical record carrier start-up time and is useful for DVD, HD-DVD and BD recorders and/or players.

Abstract: An optical pickup device corresponding to an optical recording medium having a plurality of recording layers, and an optical drive using the device are provided. The optical pickup device includes a collimator lens disposed between an object lens and a light source. The collimator lens adjusts a focal length with respect to the optical recording medium, and the object lens focuses light passing through the collimator lens, on the optical recording medium. The object lens is optically optimized for an upper or second-upper recording layer of the optical recording medium.

Abstract: An optical disk reader or read/write system for CD or DVD formats. First and second laser diodes operating at different wavelengths have their output beams collimated and directed at a single element objective lens, and are then reflected off the disk back through the lens to a photodetector. The single element objective lens has a central aperture zone and an outer aperture zone, the central zone being profiled to operate at a first numerical aperture at approximately 0.45 and the output beam of the first laser diode is confined to the central aperture zone. The outer aperture zone together with the central aperture zone are profiled to operate at a second numerical aperture, for example 0.60 wherein the output beam of the second laser diode has ray fans extending across the full aperture of the single element objective lens.