Abstract: Provided is a recording apparatus including a self-excited oscillation semiconductor laser that has a double quantum well separate confinement heterostructure and includes a saturable absorber section to which a negative bias voltage is applied and a gain section into which a gain current is injected, an optical separation unit, an objective lens, a light reception element, a pulse detection unit, a reference signal generation unit, a phase comparison unit, a recording signal generation unit, and a control unit.

Abstract: An optical disc apparatus includes a light separator configured to separate a light beam emitted from a light source into a main beam and a sub-beam, an objective lens configured to, when the light beam is condensed and irradiated to an optical disc having a uniform recording layer in which a track is formed by record marks, irradiate at least part of the sub-beam to an area where the main beam is not irradiated in a radial direction which is defined as a direction of radius of the optical disc, and a signal generating unit configured to generate a mark layer distance signal, representing a distance between a focus of the light beam and a mark layer to which the track belongs, based on a return light beam resulting from at least one of the main beam and the sub-beam, which has been irradiated to the track.

Abstract: A method for manufacturing a microlens includes forming a microlens by pressing a microlens mold having a reverse shape of a microlens formed therein on a microlens-forming film formed on a substrate to transfer the reverse shape of the microlens to the microlens-forming film. The microlens mold is formed by irradiating an inorganic resist film which is formed on a mold substrate with exposure light by relative two-dimensional scanning, and etching an exposed region of the inorganic resist film to form the reverse shape of the microlens. The irradiation intensity of the exposure light is adjusted to correspond to the depth of the reverse shape of the microlens from the surface of the inorganic resist film on the basis of profile data of the reverse shape of the microlens.

Abstract: A laser device includes a semiconductor laser, a signal generating circuit generating a pulse signal for driving the semiconductor laser, an amplifying circuit amplifying the pulse signal, and a control circuit unit provided between the amplifying circuit and the semiconductor laser and controlling the pulse signal by letting alternating-current components of the pulse signal pass through and removing at least part of direct-current components of the pulse signal.

Abstract: An optical information recording medium includes a recording layer in which a track is formed, the track having recording marks linearly arranged thereon. Each recording mark has a dimension corresponding to a reference mark length, which serves as a reference, in a track direction along which the track extends, the dimension being smaller than dimensions of the recording mark in two directions perpendicular to the track direction.

Abstract: An optical disc recording medium is irradiated with laser light having a predetermined laser power to deform an irradiated portion of a substrate into a protruding portion. Since the substrate is deformed so as to have protruding portions, a reflecting layer arranged on the substrate is also deformed so as to have protruding portions. For a pit, the deformed state of a protruding portion allows to obtain a reproduced signal level equivalent to that in each land. For a land, the deformed state of a protruding portion allows to obtain a reproduced signal level equivalent to that in each pit. Since the deformed state of each protruding portion can be controlled on the basis of the power of the laser light for irradiation, pit-to-land deformation and land-to-pit deformation can be performed by setting the laser power. Thus, recorded data can be rewritten on the optical disc recording medium recorded with the data using a combination of pits and lands formed in the substrate.

Abstract: A recording apparatus for recording information on an optical recording medium includes a mode-locked laser unit that includes a semiconductor laser emitting a laser beam for recording the information on the optical recording medium, and an external resonator, an optical modulation unit that amplifies and modulates the laser beam emitted from the mode-locked laser unit, a recording signal generation unit that generates a recording signal based on a reference signal from a drive of the optical recording medium, and a modulation unit that generates a modulation signal for driving the optical modulation unit by latching the recording signal using a laser clock generated by an oscillation pulse of the laser beam emitted from the mode-locked laser unit.

Abstract: A recording device that records information in an optical recording medium includes: a self excited oscillation semiconductor laser including a saturable absorber section to apply a bias voltage and a gain section to inject a gain current, and also emitting a laser light to record the information in the optical recording medium; a reference signal generation unit generating a master clock signal and also supplying an injection signal synchronized with the master clock signal to the gain section of the self excited oscillation semiconductor laser; and a recording signal generation unit generating a recording signal based upon the master clock signal and also applying the recording signal to the saturable absorber section of the self excited oscillation semiconductor laser as the bias voltage.

Abstract: A recording apparatus, which records information in an optical recording medium, includes: a mode-lock laser unit including a saturable absorber section that applies a bias voltage, a gain section that feeds a gain current, a semiconductor laser that emits laser light used to record the information on the optical recording medium, and an external resonator; an optical modulation unit performing amplification modulation on the laser light emitted from the mode-lock laser unit; a reference signal generation unit generating a master clock signal and supplying a signal synchronized with the master clock signal to the gain section of the semiconductor laser; a recording signal generation unit generating a recoding signal based on the master clock signal; and a driving circuit generating a driving pulse used to drive the optical modulation unit based on the recording signal.

Abstract: An optical disk apparatus appropriately adjusts the optical paths of a reference light beam and information light beam in an optical path forming section of an optical pickup, condenses the reference light beam and information light beam using an objective lens, and performs position control of the objective lens in the focusing and tracking directions so as to focus the reference light beam onto a reference track in a target mark layer, thereby focusing the focal point of the information light beam condensed by the objective lens onto a target track TG in the target mark layer.

Abstract: An optical information recording medium includes a recording layer in which a track is formed, the track having recording marks linearly arranged thereon. Each recording mark has a dimension corresponding to a reference mark length, which serves as a reference, in a track direction along which the track extends, the dimension being smaller than dimensions of the recording mark in two directions perpendicular to the track direction.

Abstract: The recording accuracy of information on an optical disc is increased. An information optical system (150) of an optical disc apparatus (110) enables a semiconductor laser (3) to sequentially output specific peak light (LEP) and specific slope light (LES) as an information light beam (LM) and enables the correction lens (162) to change the divergence angle of the specific peak light (LEP) so that an absorption change area (RA) by the specific peak light (LEP) can be positioned at a far position in the recording layer (101). Thus, it is possible to form an energy concentration area (RE) by the specific slope light (LES) in the vicinity of a target position (QG), and the recording accuracy of information on the optical disc (100) can be increased.

Abstract: According to the present invention, there is provided a method of recording a unique ID to a read-only optical disc based on the 17PP modulation. The read-only optical disc (1) has set thereon a specific physical cluster to which a unique ID is to be recorded. With user data to be recorded to the specific physical cluster being made all zero (0), a pit/land pattern is formed, and a molding machine using a molding die is used to form many optical discs in the common manner. Thereafter, an ID unique to each optical disc is generated, and a land in a predetermined position in the specific physical cluster is transited to a pit by irradiating high-power laser light to the land correspondingly to the bit information, so that the pit/land pattern will comply the 17PP modulation rule even after the transition of the land to the pit.

Abstract: A light oscillation device has a self oscillation semiconductor laser that has a double quantum well separated confinement heterostructure made of GaInN/GaN/AlGaN materials and that includes a saturable absorber section which is applied with a negative bias voltage and a gain section into which a gain current is injected, a light separation unit that separates a portion of laser light beams from the self oscillation semiconductor laser, a light sensing element that senses the laser light beams separated by the light separation unit, and a current control circuit which controls a current injected into the gain section of the self oscillation semiconductor laser based on an amount of the laser light beams which are sensed by the light sensing element.

Abstract: An optical disc recording device includes: an optical disc device to record optical recording data onto an optical disc; a recording data assigning unit to divide a recording region on the optical disc into multiple divisions, part as a data region, assign optical recording data thereto; a redundancy data calculating unit to calculate redundancy data for restoring recorded data; a redundancy data assigning unit to take divided regions other than the data region as a redundancy region, and assign the corresponding redundancy data thereto; a recording/playing device having a recording capacity greater than the data region; and a recording control unit configured to record optical recording data in the data region and also at least a part thereof in the recording/playing device, cause the recording/playing device to play the optical recording data recorded therein at the time of calculating redundancy data, and record calculated redundancy data in the redundancy region.

Abstract: A laser device includes a semiconductor laser, a signal generating circuit generating a pulse signal for driving the semiconductor laser, an amplifying circuit amplifying the pulse signal, and a control circuit unit provided between the amplifying circuit and the semiconductor laser and controlling the pulse signal by letting alternating-current components of the pulse signal pass through and removing at least part of direct-current components of the pulse signal.

Abstract: An optical recording medium is provided. The optical recording medium includes at least a reflective film and a cover layer on a substrate; main data by a combination of pit and land are recorded on the substrate; a write-once recording is made to be possible on the reflective film by irradiating a laser light; sub-data are recorded by a mark that is formed by the irradiation of laser light for the write-once recording with respect to the reflective film; a reproducing signal level at portion where said mark is formed increases for the land of specified length; the mark by which the reproduced level decreases at the portion where the mark is formed is formed for an optical disc recording medium manufactured by physical copy; the reflective film is composed of an Ag-alloy film of Ag100-xXx(0<x<100); and the X is selected from Ti, W, Ta, V, Mo, Nb and Zr.

Abstract: An optical disc device that irradiates a light beam on an optical disc having a recording layer in which information is recorded and a positioning layer in which tracks for specifying a recording position of the information in the recording layer are provided includes an information recording unit that irradiates a light beam for information on a target position in the recording layer to record the information by shifting a position in an optical axis direction of the light beam for information, a terminal-end recognizing unit that recognizes, when new information is recorded in a recording layer having a recorded area in which information is already recorded, a terminal end of the recorded area, and a target-position setting unit that sets the target position to separate the terminal end of the recorded area and a start end of a recording planned area in which information is recorded anew.

Abstract: An optical disc apparatus that records recording marks in a plurality of mark layers by irradiating predetermined light onto a disc-like volume type recording medium on the basis of information to be recorded is disclosed. The apparatus includes: a first focus position adjusting means for adjusting the position of a focus on which a first light beam focuses within the volume type recording medium, in the direction of an optical axis of the first light beam; a second focus position adjusting means for adjusting the position of a focus on which a second light beam focuses within the volume type recording medium, in the direction of an optical axis of the second light beam; a focus control means for controlling the first focus position adjusting means and the second focus position adjusting means; and a recording control means for forming the recording marks at the positions of respective focuses.

Abstract: An optical recording medium includes recording layers and intermediate layers. The recording layers include a diffraction grating that has a predetermined grating pitch and is obtained by alternately laminating first layers and second layers being transparent and having slightly different refractive indexes. The intermediate layers are transparent and have a larger thickness than that of the recording layers. In the optical recording medium, the recording layers and the intermediate layers are alternately laminated.