Abstract: A main information area 31 capable of recording an information signal and a subsidiary information area 32 for recording subsidiary information that is different from the information signal are divided in one principal plane direction of a substrate, and an information layer for recording the information signal in the main information area 31 is provided also in the subsidiary information area 32, and medium identification information for distinguishing the medium optically is recorded in the information layer of the subsidiary information area 32 without changing the shape of the information layer. As a result, the medium identification information can be recorded in an optical recording medium 1 stably. In particular, the initialization of a phase change type optical recording medium and the recording of the medium identification information can be performed at the same time, so that the production process can be simplified, and the production costs can be reduced.

Abstract: A main information area 31 capable of recording an information signal and a subsidiary information area 32 for recording subsidiary information that is different from the information signal are divided in one principal plane direction of a substrate, and an information layer for recording the information signal in the main information area 31 is provided also in the subsidiary information area 32, and medium identification information for distinguishing the medium optically is recorded in the information layer of the subsidiary information area 32 without changing the shape of the information layer. As a result, the medium identification information can be recorded in an optical recording medium 1 stably. In particular, the initialization of a phase change type optical recording medium and the recording of the medium identification information can be performed at the same time, so that the production process can be simplified, and the production costs can be reduced.

Abstract: A method and an apparatus are provided, which enable a user's standby time to be shortened or utilized effectively in the course of recording/reproduction of information with respect to an optical disk. Information recorded on a disk is reproduced preferentially, and after counting for a predetermined period of time, recording learning is conducted. Alternatively, management information is reproduced preferentially over recording learning, and recording learning is conducted while a user is confirming this information. Alternatively, the possibility of recording on a disk is identified, and reproduction preference or recording learning preference processing is conducted based the possibility. Alternatively, a rotation speed of a disk is controlled to be variable or constant, based on the possibility of recording.

Abstract: An optical information recording medium includes a plurality of recording layers, a reflectance of at least one of the plurality of the recording layers in a non-initialized state with respect to a light beam for initialization being smaller than a reflectance of the same in an initialized state with respect to the light beam for initialization. The recording layers are initialized by irradiating, among the plurality of recording layers, the recording layer positioned farther from a light beam irradiation side with the light beam prior to irradiating the recording layer positioned closer to the light beam irradiation side, so that the initialized recording layers have no initialization irregularities.

Abstract: The object of the present invention is to make an appropriate determination of whether recording is prohibited or not depending on the type of record/reproduce apparatus. To achieve the object, optical disk 1 of the present invention that can record or reproduce information through irradiation with laser light comprises a recording area 6 for recording the information, and a management area for recording management information of the optical disk 1, wherein the management area includes a recordable write-inhibit flag area 7 with a record/reproduce apparatus, and at least two types of the identifying information that are independent one another and identify whether recording is prohibited or not respectively for at least two recording linear velocities are recorded in the write-inhibit flag area 7.

Abstract: A plurality of types of recording pulse control rules for which the recording pulse waveform is determined according to the information signals to be recorded are stored in advance in an optical disk. When recording to the optical disk, information is recorded using a recording pulse where, due to the focused laser beam, the temperature in the recording layer cools more rapidly at a second information recording layer closer to the side where light is incident than at a first information recording layer farther away from the side where light is incident.

Abstract: A main information area 31 capable of recording an information signal and a subsidiary information area 32 for recording subsidiary information that is different from the information signal are divided in one principal plane direction of a substrate, and an information layer for recording the information signal in the main information area 31 is provided also in the subsidiary information area 32, and medium identification information for distinguishing the medium optically is recorded in the information layer of the subsidiary information area 32 without changing the shape of the information layer. As a result, the medium identification information can be recorded in an optical recording medium 1 stably. In particular, the initialization of a phase change type optical recording medium and the recording of the medium identification information can be performed at the same time, so that the production process can be simplified, and the production costs can be reduced.

Abstract: In an optical information recording medium having at least two information layer, guide grooves for tracking or sample pits or information pits corresponding to information signals are formed on a surface of a first substrate. A first information layer formed by a thin film for reflecting a portion of a light beam made incident on the first substrate and permitting penetration of a portion of the light beam is formed on a surface of the first substrate. Guide grooves for tracking or information pits corresponding to information signals are formed on a surface of a second substrate. A second information layer having a reflectance higher than that of the first information layer is formed on a surface of the second substrate. Between the first information layer and the second information layer, there is formed a transparent separation layer for positioning the first information layer and the second information layer to be spaced a predetermined distance apart from each other.

Abstract: A light generating apparatus includes: a submount; a semiconductor laser chip mounted on the submount; a substrate which is mounted on the submount and includes an optical waveguide; and a substance having a predetermined thickness which is disposed between the semiconductor laser chip and the substrate. In an oscillation wavelength stabilizing apparatus for a light source, the light source is a semiconductor laser which includes: an active region for providing gain; and a distributed Bragg reflection (DBR) region for controlling an oscillation wavelength.

Abstract: A plurality of optical heads each of which comprises an independent light source and optical system are provided on the same side with respect to a recording medium having a plurality of recording layers. Alternatively, with respect to at least one light source in an optical head having a single objective lens and a plurality of light sources, an optical path correction system is provided on an optical path unique to the light source, and while light emitted from one light source is focused on a specific recording layer by shifting of the objective lens, light irradiated from another light source is focused on another recording layer by the optical path correction system. Thus, information can be reproduced from or recorded in a plurality of recording layers simultaneously and an error in focusing of light onto the plurality of recording layers can be suppressed.

Abstract: An optical information recording device includes a linear velocity setting circuit for setting a first linear velocity v1 and a second linear velocity v2 higher than the first linear velocity v1 for a optical information recording medium, a recording pulse generation circuit for generating a recording pulse signal, depending on the setting by the linear velocity setting circuit, and a laser drive circuit for irradiating the medium with the laser light based on the recording pulse signal generated by the recording pulse generation circuit.

Abstract: In an optical information recording medium having at least two information layer, guide grooves for tracking or sample pits or information pits corresponding to information signals are formed on a surface of a first substrate. A first information layer formed by a thin film for reflecting a portion of a light beam made incident on the first substrate and permitting penetration of a portion of the light beam is formed on a surface of the first substrate. Guide grooves for tracking or information pits corresponding to information signals are formed on a surface of a second substrate. A second information layer having a reflectance higher than that of the first information layer is formed on a surface of the second substrate. Between the first information layer and the second information layer, there is formed a transparent separation layer for positioning the first information layer and the second information layer to be spaced a predetermined distance apart from each other.

Abstract: An optical information recording medium is provided with a plurality of information layers (2, 3), each of which has a sector structure in which a data area (8, 12) is divided in the circumferential direction by a sector address (9, 13). The positions of the sector addresses (9, 13) of the respective information layers (2, 3) coincide in the circumferential direction. This can prevent errors during reproduction caused by the effect of other information layers and stabilize recording characteristics, resulting in an increased recording capacity of a rewritable recording medium having a plurality of information layers with a sector structure.

Abstract: An optical information recording and reproducing apparatus for recording and reproducing an information signal on/from both concave portions and convex portions of guide grooves formed on a recording medium is disclosed.

Abstract: The width W of the address pit (9) of an optical recording medium of intermediate address type is determined by W=k Tp/(?/NA) where ? is the laser wavelength of the optical head of the optical disk device use, NA is the numerical aperture of the objective, Tp is the track pitch of the record medium, and k is 0.40?k?0.68. Alternatively, an optical device comprises a first address demodulating circuit for demodulating address information by using a signal that is the sum of the electric signals outputted from a pair of photodetectors separated in the direction of the track and a second address demodulating circuit for demodulating address information by suing a signal that is the difference between the electric signals. The address is detected base on the information thus obtained.

Abstract: A method by which, in an optical disk recording and reproducing device, the time required for a test recording performed prior to an actual information recording can be reduced according to characteristics of an optical disk. A random pattern signal is transmitted from a random pattern signal generating circuit 3 and recorded on a test track on an optical disk 1, and a bit error rate of a reproduction signal is measured. Only when a value of the bit error rate is not less than a fixed value, test pattern signals are transmitted from a test pattern signal generating circuit 4 and recorded. An edge timing of a reproduction signal is measured by an edge timing detecting circuit 13. Based on a result of the measurement, edge positions of a front-end pulse and a back-end pulse are corrected.

Abstract: A plurality of optical heads each of which comprises an independent light source and optical system are provided on the same side with respect to a recording medium having a plurality of recording layers. Alternatively, with respect to at least one light source in an optical head having a single objective lens and a plurality of light sources, an optical path correction system is provided on an optical path unique to the light source, and while light emitted from one light source is focused on a specific recording layer by shifting of the objective lens, light irradiated from another light source is focused on another recording layer by the optical path correction system. Thus, information can be reproduced from or recorded in a plurality of recording layers simultaneously and an error in focusing of light onto the plurality of recording layers can be suppressed.

Abstract: An optical information recording medium is provided which has favorable signal quality even in high density recording using a translucent information layer. The optical information recording medium includes one or more information layers including a recording layer for recording/reproducing an information signal by irradiation with a laser light, and a separating layer or a protective substrate on which a first information layer of the information layer on the irradiation face side is formed, the separating layer or the protective substrate having a guide groove spirally or concentrically formed on the surface, and the respective inclined planes on the inner perimeter side and the outer perimeter side of the guide groove having inclined angles ? and ? with respect to the bottom face of the guide groove. The guide groove has one or more dissymmetric regions in the radius direction where the inclined angles ? and ? are different.

Abstract: In an optical information recording medium having at least two information layer, guide grooves for tracking or sample pits or information pits corresponding to information signals are formed on a surface of a first substrate. A first information layer formed by a thin film for reflecting a portion of a light beam made incident on the first substrate and permitting penetration of a portion of the light beam is formed on a surface of the first substrate. Guide grooves for tracking or information pits corresponding to information signals are formed on a surface of a second substrate. A second information layer having a reflectance higher than that of the first information layer is formed on a surface of the second substrate. Between the first information layer and the second information layer, there is formed a transparent separation layer for positioning the first information layer and the second information layer to be spaced a predetermined distance apart from each other.

Abstract: During reproduction of a multilayer recording medium including three or more information layers, a light beam is irradiated onto a target information layer. A reflected light from the information layer is mainly detected to generate an information signal RF1, while reflected lights from the other information layers than the target layer are detected to generate an information signal RF2. The signal RF2 is amplified by a gain which is adjusted based on a predetermined cross talk information. A difference between the information signal RF1 and the amplified cross talk signal RF2 is obtained to cancel a component of the cross talk signal in the information signal RF1 and generate a reproduction signal RF3 indicating information recorded in the target information layer to be reproduced.