Abstract: In certain inventive aspects there are provided an optical recording method, an evaluation indicator acquiring method, an optical recording apparatus, and a CPU device, which can save a test time before recording information. An irradiation condition suitable for recording information on a first recording layer is extracted by recording and reproducing test information. The test information is recorded on and reproduced from a second recording layer. The irradiation condition suitable for recording information on the second recording layer is extracted on the basis of the test result for the first recording layer and the test result for the second recording layer. Accordingly, it is possible to save the test time for extracting the irradiation condition of the second recording layer.

Abstract: A focus layer jump control circuit may include a signal processing block that converts an analog focus error (FE) signal into a digital FE signal, in response to the analog FE signal and a FE selection signal; a layer jump control block that outputs a second control signal, in response to the digital FE signal and a reference clock signal; a focus main filter block that outputs first and second compensation signals that amplify the digital FE signal and that compensate for a phase of the digital FE signal, in response to an internal selection signal; an exponent signal generator that generates an exponent signal, in response to a focus layer jump indicating signal and a first control signal; and an output circuit that outputs a first-order difference signal using the exponent signal, the first compensation signal, and the second compensation signal, in response to the second control signal.

Abstract: An optical disk differentiating method applied to an optical disk drive, in which a first level value, a second level value and an optical disk differentiating value generating program are stored and an optical disk is put.

Abstract: An optical head that is restrained from becoming larger, even if it is used for an optical-information recording medium that includes a plurality of information recording layers. In this optical head, a collimating lens is formed by a concave lens disposed on the side of a light source and a convex lens disposed on the side of an objective lens. A collimating-lens actuator moves the convex lens in a direction where a spherical aberration is cancelled which is generated according to the thickness of a light transmission layer up to an information recording layer of the optical-information recording medium. An aperture stop is provided on the side of the collimating lens with respect to the objective lens, and the aperture stop is located near the focal position of the convex lens on the side of the objective lens.

Abstract: An optical disc is based on the following the distance of the light transmission layer from a light incidence plane to the first recording layer is a minimum of 550 ?m. The distance between the first and the third recording layer is a maximum of 72 ?m. The distance between the second and the third recording layer is a minimum of 15 ?m. The distance between the first and the second recording layer is about 31 to 40 ?m. The reflectivities of the first and the second recording layer with respect to the first laser beam are 18% or more, and the ratio between the reflectivities is about 1.15 or less. The areal recording density of the third recording layer is three times or more as high as the areal recording density of the first and the second recording layer.

Abstract: The present invention relates to a read-once record medium, comprising: a data substrate, having control data zone and a data zone, and said having pre-record data; a sensitive layer, disposed above said data substrate; a refractive layer, disposed above said sensitive layer; an adhesive layer, disposed above said refractive layer; and a transparent substrate, disposed above said adhesive layer; thereby, the structure of said sensitive layer or said data substrate will be changed when laser beams with specified power emitted from an optical storage device pass through the data substrate and focus on the sensitive layer, and the laser beams will be reflected by the sensitive layer and can not be recognized by the optical storage device. Furthermore, the present invention also provides a system with read protecting function.

Abstract: An optical disc driving device includes a control circuit 4 for performing a gain adjustment for each of two recording surfaces of a multilayered optical disc 1 on the basis of an FE signal in such a way as to maintain a state in which light is focused onto either of the recording surfaces, to generate a focus servo loop signal, and for generating a focus jump signal for causing either a transition from a state in which the light is focused onto one recording surface to a state in which the light is focused onto the other recording surface, or a transition in the opposite direction from a threshold set up on the basis of an amount of gain adjustment, and a focus actuator driving circuit 5 for performing either a focus jump or an operation of maintaining the state in which the light is focused.

Abstract: An optical information recording apparatus includes a recording layer, wherein nanoparticles having diameters of 100 nm or less are disposed while being surrounded by a medium having a complex dielectric constant which is changed in accordance with an application of light and the degree of local plasmon resonance produced by the nanoparticles is changed in accordance with the change in the complex dielectric constant of the medium.

Abstract: The present invention relates to apparatuses and processes for recording dye-based recordable DVD media in higher quality at higher linear recording velocity, and provides an apparatus for recording a dye-based recordable DVD medium comprising a shortest mark recording unit, a second mark recording unit, and a cooling pulse irradiating unit, wherein the dye-based recordable DVD medium comprises a substrate and a recording layer formed on the substrate, the substrate comprises a guide groove to which wobble is formed, and the recording layer comprises at least an organic dye, the shortest mark recording unit is configured to record each of the shortest marks by use of one pulse beam of which the rear edge is more energized than the front edge, the second mark recording unit is configured to record each of the marks other than the shortest marks by use of one pulse beam of which the two sites of front and rear edges are energized, the cooling pulse irradiating unit is configured to irradiate cooling pulse laser

Abstract: An optical disk and a method for identifying the optical disk making it possible to identify a recording system of the optical disk easily in a short time by a recording and reproduction apparatus when a groove-recording system and a land-recording system are both employed in one kind of optical disk, such as, for example, a BD-R. Specifically, a polarity upon reproducing wobble information is made to be the same in both an optical disk of groove-recording system and the optical disk of a land-recording system. The recording system of the optical disk that shows the same wobble polarity irrespective of the recording system can be easily detected by finding a tracking polarity that can recognize the wobble information by changing the tracking polarity, whereby the start-up time of the recording and reproduction apparatus can be shortened.

Abstract: A multilayer optical recording medium includes three or more recording layers formed in a thickness direction. Trial writing areas provided in the respective recording layers to adjust the power of recording laser are formed not to overlap at a position in a planar direction in adjacent ones of the recording layers. Further, the trial writing areas are formed to have an overlapping portion at a position in the planar direction in one of the recording layers and at least another one of the recording layers not adjacent to the one of the recording layers.

Abstract: An information recording medium comprises a substrate, a second recording layer, a second light transmitting layer, a first recording layer for recording different information from that to be recorded in the second recording layer, and a first light transmitting layer. The second recording layer is formed with a continuous second microscopic pattern of grooves. The first recording layer is formed with a continuous first microscopic pattern of grooves that is different from the second microscopic pattern. Both sidewalls of raised portions of the first and second microscopic patterns are formed with wobbling so as to be parallel with each other. Auxiliary information and a reference clock is recorded on these sidewalls alternately and continuously.

Abstract: A multilayer optical disk apparatus comprises an optical pickup that emits N (N represents an integer of two or more) laser beams of the same wavelength. The optical pickup emits the N laser beams at the same time, focuses the N laser beams on a first recording layer group alternately configured by N recording layers of the multilayer optical disk and performs a recording operation on the N recording layers at the same time. When changing the recording layers the optical pickup focuses the N laser beams on a second recording layer group configured by recording layers adjacent to the respective recording layers configuring the first recording layer group and performs a recording operation on the N recording layers at the same time.

Abstract: An object of the invention is to provide an optical-recording medium in which problems such as cross-write, i.e., signals are recorded wrongly on adjacent tracks, and cross-erase i.e., recording signals on adjacent tracks are erased wrongly, can be solved, and which enables high-density recording; a method for producing the optical-recording medium; and a method for recording and reproducing an optical-recording medium. To achieve this object, the optical-recording medium includes a substrate, an optical-absorption layer which absorbs light and generates heat on or above the substrate, a recording layer, and record-blocking portions which block recording on the recording layer, in which the record-blocking portions are disposed between the recording layer and the optical-absorption layer, and between adjacent tracks, and recording marks are formed on the recording layer by the optical absorption function of the optical-absorption layer.

Abstract: A recording medium includes: at least one recording layer on which information is recorded by multi-photon absorption; and a servo layer disposed in a laminated direction with respect to the recording layer and having a track for guiding a beam spot of laser light having a first wavelength and a beam spot of laser light having a second wavelength along a scanning trajectory, wherein the servo layer and the at least one recording layer constitute a set of layers, and a plurality of sets of layers is formed in the laminated direction.

Abstract: An indolium compound is represented by formula (I): Ring A: a benzene or naphthalene ring. Ring B: 5- or 6-membered heterocyclic or aromatic ring. Z: alkyl group having 1-8 carbon atoms, may be substituted with a halogen atom or interrupted by —O—, —CO—, —OCO—, or —COO—, a sulfonyl group having a hydrocarbyl group having -8 carbon atoms, a sulfinyl group having a hydrocarbyl group having 1-8 carbon atoms, an alkylamino group having an alkyl group having 1-8 carbon atoms, a dialkylamino group having alkyl groups having 1-8 carbon atoms, a cyano group, a nitro group, a hydroxyl group, or a halogen group. R1: group represented by formula (II) or (II?). R2: organic group having 1-30 carbon atoms or group represented by formula (II), (II?), or (III). Y: group represented by formula (III). n: integer 0-4; Anm?: m-valent anion, m is 1 or 2.

Abstract: The invention discloses a method and a device for recording information on a multi layer optical disc using a multi session format. The use of multi sessions allows for an efficient use of the storage capacity of the disc, and for a fast finalization time.

Abstract: The present invention provides an information recording apparatus capable of reproducing recorded recording information without giving strange feeling even in the case where it is necessary to switch a recording layer among multiple recording layers, and an information recording program for executing the information recording process. An information recording apparatus R for recording “recording information Sr” to an optical disk DK having a plurality of recording layers L0 and L1 has a CPU 4 for detecting the content of the recording information Sr during recording of the recording information Sr to the recording layer L0, on the basis of the detected content, switching the recording layer L0 to which the recording information Sr is switched to the recording layer L1, and continuing recording of the recording information Sr.

Abstract: Disclosed is an optical disc apparatus that sets a plurality of virtual zones, which correspond to a plurality of zones that are arranged in the radial direction of an optical disc, for a plurality of recording layers of the optical disc. When a servo signal distortion is detected in a virtual zone to change the rotation speed of the optical disc to a low speed in the virtual zone during an information recording or reproduction operation relative to a first recording layer, the optical disc apparatus stores the change information. When a recording or reproducing operation is to be performed in a virtual zone of a second recording layer, which is in the same disc radial position as the virtual zone of the first layer, the optical disc apparatus changes the rotation speed of the optical disc for the virtual zone to a low speed in accordance with the change information.

Abstract: A multilayer information storage medium according to the present invention includes: a substrate; at least three information storage layers, which are stacked one upon the other on the substrate; a plurality of transparent layers, each of which is arranged between its associated adjacent ones of the information storage layers; and a transparent coating layer. At least two of the transparent layers have mutually different thicknesses. If a laser beam with a wavelength of 400 nm to 410 nm is incident perpendicularly on the medium through the transparent coating layer, two of the information storage layers that sandwich the thinnest one of the transparent layers have a higher returning light intensity and/or a higher degree of modulation than the other information storage layers.

Abstract: Recordable DVD+R and DVD+R/W optical discs with two (or more) information layers are developed to double the data storage capacity and video recording time. A method and device are proposed to make dual layer DVD disc recordings compliant with the dual layer DVD-ROM standard Recording the data in a DVD-ROM compliant way on the dual layer DVD+R or DVD+R/W disc is obtained by shifting the middle zone area towards the inner radius of a disc in such a way that the data zones of both layers are filled up with data.

Abstract: A high-density multi-layer optical disc and a method for managing layer formatting thereof. A high-density multi-layer optical disc such as a Blu-ray disc rewritable (BD-RE) dual layer includes management information, additionally recorded in a lead-in area, needed for identifying formatting status of a plurality of recording layers. After the management information is referred to, at least one unformatted recording layer is automatically formatted. Optionally, the unformatted recording layer is formatted on the basis of a formatting method selected by a user. The multiple recording layers formed on the high-density multi-layer optical disc can be conveniently and effectively formatted.

Abstract: A high-density multi-layer optical disc and a method for managing layer formatting thereof. A high-density multi-layer optical disc such as a Blu-ray disc rewritable (BD-RE) dual layer includes management information, additionally recorded in a lead-in area, needed for identifying formatting status of a plurality of recording layers. After the management information is referred to, at least one unformatted recording layer is automatically formatted. Optionally, the unformatted recording layer is formatted on the basis of a formatting method selected by a user. The multiple recording layers formed on the high-density multi-layer optical disc can be conveniently and effectively formatted.

Abstract: An optical recording medium comprises a transparent lower disk and an upper disk secured together by a transparent intermediate member. On one side of the lower disk, groove tracks of width WG0 and land tracks of width WL0 are formed. All tracks of the lower disk are coated with a recording film on which a laser beam is incident from below and a reflecting film on the recording film for partially reflecting the laser beam. The upper disk is formed with land tracks of width WL1 and groove tracks of width WG1 for receiving light through the corresponding groove and land tracks of the lower disk. All tracks of the upper disk are also coated with laminated recording and reflecting films. The ratio WG1/WL1 of the upper disk is greater than unity and is equal to or greater than the ratio WG0/WL0 of the lower disk so that the carrier-to-noise ratios of the two disks are substantially equal to each other.

Abstract: A multi-layer optical writable disc (D) comprises at least two layers (L1, L2, . . . ) and at least two defect management areas (DF1, DF2, . . . ). A first defect management area (DF1) is positioned on a first layer (L1) of the at least two layers at a first radial position (RP1), and a second defect management area (DF2) is positioned on a second layer (L2) of the at least two layers at a second radial position (RP2). The first radial position (RP1) and the second radial position (RP2) are different.

Abstract: An information reproducing apparatus (200) is provided with: a reproducing device (202, 205, 206) for reproducing record information recorded on an information recording medium (100) which is provided with a first recording layer (L0) to which first medium region information (110) is assigned and a second recording layer (L1) to which second medium region information (120) is assigned; a storing device (209) for storing apparatus region information (230); a judging device (207) for judging whether or not the second medium region information matches the apparatus region information if the first medium region information does not match the apparatus region information; and a controlling device (207) for controlling the reproducing device to reproduce the record information recorded in the second recording layer if it is judged that the second medium region information matches the apparatus region information.

Abstract: A method for setting a layer-jump point on a multilayer optical disc in an optical drive for accessing the multilayer optical disc. First, a magnetic-pole cycle value is accumulated. Next, a lag control signal of the optical drive is detected to record the magnetic-pole cycle value as a magnetic-pole basic value. Then, a magnetic-pole offset value is generated according to a phase difference between the lag control signal and an oscillating position of the multilayer optical disc. Finally, a layer-jump-point reference value, according to which the optical drive moves from one layer of the multilayer optical disc to another layer thereof to access data, is set by adding the magnetic-pole basic value to the magnetic-pole offset value.

Abstract: An optical pickup (100) includes: (i) a light source (101) for emitting a laser beam; (ii) an optical system (105, etc.) for introducing the laser beam into one of recording layers; (iii) an optical function element (104) for changing a predetermined polarized state in the laser beam in the unit of micro regions contained in the region where the laser beam is applied for each of the micro region positions; and (iv) light receiving means (PD0, etc.) for receiving at least the laser beam.

Abstract: The invention provides a reproduction apparatus that reproduces information recorded in a recording medium having plural recording layers, including: an optical head that irradiates laser beams on the respective recording layers and detects reflected light information to read out information recorded in the respective recording layers; a shaft sliding type focus actuator that holds the object lens; a focus servo section that generates a focus servo drive signal and drives the focus actuator such that a focus state of the laser beams is kept in a state of focus on a recording layer on which the reproduction is performed; and a focus jump control section that generates a kick signal for starting focus jump movement by the focus actuator and a brake signal for ending the focus jump movement.

Abstract: An optical read/write apparatus causes a read/write light beam from illuminating means to strike only one side of an optical storage medium including stacked data storage layers each of which is readable/writeable separately from the other layers. In this case, the optical read/write apparatus operates so that data is read/written from/into a second data storage layer after fully recording a recordable area of a first data storage layer. Thus, light can be shone with uniform intensity across the substantially entire recordable area of the second data storage layer without using a complex read/write system even under such conditions that the transmittance to light of the first data storage layer in the recordable area may vary depending on whether any data is recorded in the recordable area.

Abstract: Apparatuses, products, devices and methods, of manufacture consistent with the invention include optically readable media with at least one mechanism, chemical, agent, and/or process for limiting the time period that at least a portion of encoded information can be read and/or accessed by an optical beam and/or reader capable of reading the encoded information.

Abstract: Provided is an optical disk apparatus which optimizes a frequency of a high frequency superimposing operation upon reproduction so that good reproduction performance is realized in a wide irradiation power range of a laser power. The optical disk apparatus includes: a semiconductor laser device; an optical disk discrimination circuit for performing laser discrimination; a driver device including a drive circuit for supplying direct drive current to the semiconductor laser device and a high frequency superimposing circuit for superimposing high frequency current on the drive current; and a high frequency superimposing variable circuit for changing a frequency of the high frequency current in which when information is reproduced, the high frequency superimposing variable circuit sets the frequency of the high frequency current for reproducing a multi-layer disk to be higher than the frequency of the high frequency current for reproducing a single-layer disk.

Abstract: A data recording apparatus includes a recording medium which includes a semiconductor substrate, a first insulating layer formed on one surface of the substrate, a second insulating layer formed on the first insulating layer and is made to accumulate electric charge, an electrode layer formed on the other surface, and an insulating area which penetrates the insulating layers; and an electrode which applies a voltage to the medium. A depth from an interface between the substrate and the first insulating layer to the bottom of the insulating area is more than a maximum depth of a depletion layer, Wmax represented by Wmax=?{square root over (2?0?i×2|?f|/qNd)} where ?0, ?i, |?f|, q, and Nd are a dielectric constant of vacuum, a relative dielectric constant, an absolute value of the Felmi potential of the substrate, an electric charge of an electron, and an impurity concentration of the substrate, respectively.

Abstract: A combination optical disc (1) is disclosed, which contains at least two information layers (10, 11) of at least two different storage formats selected from for example CD, DVD, BD. Information is stored on the disc (1) concerning the storage format of the layers (10, 11). According to an embodiment of the invention, each of the formats contains information indicating that a second, or even third, format is present on the same disc. Now a device may select a Format different from the one detected during start up. Alternatively, all formats present on a single disc are identified by an identifier on the disc. Such art identifier may be located in the BCA area, a chip (4) on disc or in a bar code on the disc itself.

Abstract: A focus control section first performs a reference focus control process in which a reference optical beam is focused on a reference layer of an optical disc according to the result of receiving a reference reflection optical beam, and then switches from the reference focus control process to an information focus control process in which an information optical beam is focused on a mark layer of the optical disc according to the result of receiving an information reflection optical beam.

Abstract: Separate sets of optical medium identification information are embedded in separate aligned layers of the optical medium to allow an optical drive to initiate use of the optical medium with information from both layers. For instance, a first set of identification information is embedded in the data layer of the optical medium and a second set of identification information is embedded on the protective surface layer of the optical medium. The first and second sets of information align so that a mixed signal is provided when the optical medium is initially inserted in the optical drive with the optical drive reading the separate sets of information while the read head is at a single location.

Abstract: To reduce influence of errors on the outer periphery side of a multi-layer recording disc, a first shifted middle area is assured at a predetermined position nearer to the inner periphery side than the last position of layer on the outer periphery side of a single-sided, multi-layer recording disc, and a second shifted middle area is assured at the position of layer that opposes the shifted middle area assured on layer. A recording layer extending from layer to layer may be shifted in the first and second shifted middle areas, and an area in which errors relatively readily occur on the outer periphery side of the first and second shifted middle areas may not be used.

Abstract: A method of providing interactivity over a set of multiple optical storage media (90, 91) is disclosed. A logical unit, such as a playitem of a playlist is provided on a storage medium (90) of the set of optical storage media (90, 91), comprising information about contents stored on at least one other storage medium (91) of said set of optical storage media. Furthermore, a corresponding optical disc reading apparatus, optical storage medium, and a computer-readable medium, are disclosed.

Abstract: A recording media data structure includes a first recording layer having a lead-in area, a first user region successive to a physical sector of the lead-in area and for storing user data, and a first jump region successive to a physical sector of the first user region; a second recording layer stacked on the first recording layer, the second recording layer having a second jump region, a second user region successive to a physical sector of the second jump region and for storing user data, and a guide-out region successive to a physical sector of the second user region; wherein the lead-in area, the first jump region, the second jump region and the guide-out region each have a constant number of physical sectors, and the second jump region has a beginning physical sector successive to an ending physical sector of the first jump region.

Abstract: An optical read/write apparatus causes a read/write light beam from illuminating means to strike only one side of an optical storage medium including stacked data storage layers each of which is readable/writeable separately from the other layers. In this case, the optical read/write apparatus operates so that data is read/written from/into a second data storage layer after fully recording a recordable area of a first data storage layer. Thus, light can be shone with uniform intensity across the substantially entire recordable area of the second data storage layer without using a complex read/write system even under such conditions that the transmittance to light of the first data storage layer in the recordable area may vary depending on whether any data is recorded in the recordable area.

Abstract: An information storage medium and an apparatus for recording and/or reproducing the information storage medium are provided to control optimal recording power without an influence of an optimal power control (OPC) area in a layer upon an OPC area in a different layer. The information storage medium includes at least one information storage layer including an optimal power control area for obtaining an optical recording condition. OPC areas in adjacent information storage layers are disposed within different radiuses of the information storage medium. Accordingly, even when the information storage medium is made eccentric or has a manufacturing error, a recording property of the information storage medium is prevented from being degraded due to an influence of an OPC area in an information storage layer upon an OPC area in an adjacent information storage layer.

Abstract: An information recording medium comprises a substrate, a second recording layer, a second light transmitting layer, a first recording layer for recording different information from that to be recorded in the second recording layer, and a first light transmitting layer. The second recording layer is formed with a continuous second microscopic pattern of grooves. The first recording layer is formed with a continuous first microscopic pattern of grooves that is different from the second microscopic pattern. Both sidewalls of raised portions of the first and second microscopic patterns are formed with wobbling so as to be parallel with each other. Auxiliary information and a reference clock is recorded on these sidewalls alternately and continuously.

Abstract: The invention presents an optical element with which an optical head can be configured, in which there is little deterioration of the correctional effect when the objective lens shifts, as well as an optical head and an optical recording/reproducing apparatus using such an optical element. The invention also presents a novel optical recording/reproducing apparatus and optical recording/reproducing method. The optical element, includes a first voltage application electrode 13, a first opposing electrode 17 arranged in opposition to the first voltage application electrode 13, and a first phase changing layer 15 arranged between the first voltage application electrode 13 and the first opposing electrode 17. By changing a voltage between the first voltage application electrode 13 and the first opposing electrode 17, a phase that converts plane waves into spherical waves is imparted on light that is incident on the first phase changing layer 15.

Abstract: The present invention relates to an optical recording medium comprising a visible information recording layer comprising a dye denoted by the following general formula (I) on a support. In general formula (I), A denotes a substituted or unsubstituted heterocyclic group, substituted aliphatic group, or substituted or unsubstituted carbon ring group, and B denotes a substituted or unsubstituted heterocyclic group or a substituted or unsubstituted aryl group. The optical recording medium may further comprise a recording layer capable of recording and/or reproducing information by irradiation of a laser beam. The present invention further relates to a method of recording visible information on the visible information recording layer of the optical recording medium, wherein the visible information is recorded by using the same laser bean as that used in recording on the above recording layer.

Abstract: A multi-layer optical writable disc (D) comprises at least two layers (L1, L2, . . . ) and at least two defect management areas (DF1, DF2, . . . ). A first defect management area (DF1) is positioned on a first layer (L1) of the at least two layers at a first radial position (RP1), and a second defect management area (DF2) is positioned on a second layer (L2) of the at least two layers at a second radial position (RP2). The first radial position (RP1) and second radial position (RP2) are different.

Abstract: In a method for writing data to an information recording medium having a plurality of recording layers, user data is written across between a plurality of the recording layers, and data other than the user data is written in a predetermined zone of the recording layer. Thereby, since the user data is written continuously upon switching of a recording layer without data other than the user data being written, it is possible to avoid interruption of writing of the user data to the recording layers.

Abstract: According to one embodiment, an optical disc is the following the distance between a light incidence plane and the first recording layer is a minimum of 550 ?m. The distance between the first and the third recording layer is a maximum of 72 ?m. The distance between the second and the third recording layer is a minimum of 15 ?m. The distance between the first and the second recording layer is about 31 to 40 ?m. The reflectivities of the first and the second recording layer with respect to the first laser beam range from 18 to 27%, and the ratio therebetween is about 1.1 or less. The reflectivity of the third recording layer is below about 6%. The areal recording density of the third recording layer is three times or more as high as that of the first recording layer and the second recording layer.

Abstract: A multilayer recording medium that prevents deterioration of a signal characteristic due to a mirror effect that may occur between recording layers and a method of manufacturing the same, the multilayer recording medium having at least two recording layers, wherein a thickness of at least one spacer layer between adjacent recording layers is different from a thickness of the other spacer layers such that a beam focusing on a recording layer is prevented from focusing on another recording layer corresponding to a mirror layer due to reflection. In the multilayer recording medium, a mirror effect is greatly reduced. In addition, the thickness of only a spacer layer exerting the most significant influence on the mirror effect is changed to prevent the deterioration of signal quality due to the mirror effect, and therefore, the structure of a multilayer recording medium is simplified.

Abstract: A method of storing a data storage device includes but is not limited to emplacing a data storage device in a container, the container having surfaces; and writing storable data to the data storage device by transmitting energy through a surface of the container. In addition to the foregoing, other method aspects are described in the claims, drawings, and text forming a part of the present application. Other methods and apparatuses are also disclosed.

Abstract: A disc recording medium has recorded thereon a first program in a first recording area and corresponding first management data for managing readout of the first program and providing information, such as track number and play time, to the user. The disc recording medium also has a second program recorded in a second recording area and corresponding second management data for managing readout of the second program. The second management data includes only an absolute time code and track start time codes, but no track numbers or play times, and the track numbers are derived using the second management data.