Abstract: A multi-layer optical information recording medium has a first information layer located at the incident side for a laser beam and another information layer at the back thereof. Thus, it has a large capacity. A relationship that R1a<R1c and R2a<R2c holds for the reflectances R1a and R1c of the information layer in the in a recorded portion and in a non-recorded portion, and the reflectances R2a and R2c of the information layer in a recorded portion and in a non-recorded portion. A relationship that A1a<A1c holds between the absorptances A1c and A1a of the first information layer in the crystalline state and in the amorphous state, similarly, a relationship A2a<A2c holds between absorptances A2c and A2a of the second information layer in the crystalline state and in the amorphous state. Thus, signals can be written to the recording medium at a fast speed and at high sensitivity.

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: 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 rewriteable type optical recording medium for recording information has an information recording area for recording information and a recording/reproduction condition recording area for recording at least one recording/reproduction condition to be used in a recording/reproduction apparatus and at least one set of manufacturer information for identifying a manufacturer of a recording/reproduction apparatus which uses the at least one recording/reproduction condition. A plurality of recording/reproduction conditions and a plurality of sets of manufacturer information, each one the plurality of sets of manufacturer information corresponding to one of the plurality of recording/reproduction conditions, can be recorded on the rewriteable type optical recording medium and overwritten on the rewriteable type optical recording medium.

Abstract: An optical recording device comprises: a basic pulse generator 60 including a starting-end pulse generation circuit 2, a burst gate generation circuit 4, and an end pulse generation circuit 6; a data-length detector 61 including a front mark detector 40, a front space detector 41, a recording mark detector 42, a back space detector 43 and a back mark detector 44; a timing controller 62 including a starting-end pulse selecting circuit 14, a starting-end starting position setting circuit 15, a starting-end pulse delaying circuit 19, an end pulse selecting circuit 21, an end starting position setting circuit 35 and an end pulse delaying circuit 25; a pulse synthesizer 63 including an AND gate 27 and an OR gate 36; and a laser driver 64 including an erasing current source 32, a recording current source 33, and a switch 34.

Abstract: An optical recording medium has a recording/reproduction conditions recording area for recording recording/reproduction conditions and recording/reproduction apparatus information identifying the recording/reproduction apparatus using the recording/reproduction conditions. When the optical recording medium is accessed in a recording/reproduction apparatus, the recording/reproduction conditions for the recording/reproduction apparatus are used. Therefore, recording or reproduction can be performed with use of optimum recording/reproduction apparatus information appropriate for the optical recording medium and for the recording/reproduction apparatus. When the optical recording medium is used for the first time, test recording is performed by using a test recording region provided in the optical recording medium, and the obtained recording/reproduction conditions are recorded.

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: An optical recording medium has a recording/reproduction conditions recording area for recording recording/reproduction conditions and recording/reproduction apparatus information identifying the recording/reproduction apparatus using the recording/reproduction conditions. When the optical recording medium is accessed in a recording/reproduction apparatus, the recording/reproduction conditions for the recording/reproduction apparatus are used. Therefore, recording or reproduction can be performed with use of optimum recording/reproduction apparatus appropriate for the optical recording medium and for the recording/reproduction apparatus. When the optical recording medium is used for the first time, test recording is performed by using a test recording region provided in the optical recording medium, and the obtained recording/reproduction conditions are recorded.

Abstract: A reflectance increasing type optical information recording medium in which the crosstalk is inhibited in the land and groove recording. This optical information recording medium comprises a substrate having a groove and a land provided between adjacent grooves and a recording layer that is provided on the substrate and that changes the reflectance by irradiation with light beams. In this recording medium, the reflectance after recording is greater than the reflectance before recording. Moreover, the depth D of the groove is set to be in the range of &lgr;/8n to 3&lgr;/8n, where the wavelength of the light beam is &lgr; and the refractive index of the substrate is n. And the difference, &Dgr;&phgr;=&phgr;1−&phgr;0, between the phase &phgr;1 of the reflected light after recording and the phase &phgr;0 of the reflected light before recording is in the range of (−0.1+2 m) &pgr; to (0.1+2 m) &pgr;, where m is an integer.

Abstract: An optical recording device comprises: a basic pulse generator 60 including a starting-end pulse generation circuit 2, a burst gate generation circuit 4, and an end pulse generation circuit 6; a data-length detector 61 including a front mark detector 40, a front space detector 41, a recording mark detector 42, a back space detector 43 and a back mark detector 44; a timing controller 62 including a starting-end pulse selecting circuit 14, a starting-end starting position setting circuit 15, a starting-end pulse delaying circuit 19, an end pulse selecting circuit 21, an end starting position setting circuit 35 and an end pulse delaying circuit 25; a pulse synthesizer 63 including an AND gate 27 and an OR gate 36; and a laser driver 64 including an erasing current source 32, a recording current source 33, and a switch 34.

Abstract: An optical disk device comprising a converging optical system in which a laser beam is irradiated onto an optical disk having a recording thin film on a substrate provided with uneven guide grooves and a tracking controller that controls tracking so that the laser beam converged by the converging optical system scans a convex part or a concave part of the guide groove, wherein the tracking controller controls tracking polarity so that the tracking polarity is inverted according to the depth of the guide groove. As a result, in optical disks having any groove depth, a laser beam can scan a target groove track or a target land groove track correctly.

Abstract: A reflectance increasing type optical information recording medium in which the crosstalk is inhibited in the land and groove recording. This optical information recording medium comprises a substrate having a groove and a land provided between adjacent grooves and a recording layer that is provided on the substrate and that changes the reflectance by irradiation with light beams. In this recording medium, the reflectance after recording is greater than the reflectance before recording. Moreover, the depth D of the groove is set to be in the range of &lgr;/8n to 3&lgr;/8n, where the wavelength of the light beam is &lgr; and the refractive index of the substrate is n. And the difference, &Dgr;&phgr;=&phgr;1−&phgr;0, between the phase &phgr;1 of the reflected light after recording and the phase &phgr;0 of the reflected light before recording is in the range of (−0.1+2 m) &pgr; to (0.1+2 m) &pgr;, where m is an integer.

Abstract: The present invention relates to an optical information recording medium including a disk-shaped transparent substrate and a recording layer for recording, reproducing or erasing information by irradiation of laser light, the recording layer being formed over the substrate. The recording layer of the present invention includes information tracks including groove tracks and land tracks that are formed alternately in a radial direction of the disk. The information tracks comprise information recording regions and address regions interposed between the information recording regions, the information recording regions and the address regions being arranged along the tracking direction of the laser light.

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: An optical information recording medium provided with an information layer comprising at least Te, O and M atoms (wherein the M is at least one element selected from a metallic element, a metalloid element or a semiconductor element, most preferably Pd). The information layer comprises the O atoms in 40 atom %-60 atom %, the M atoms in 2 atom %-25 atom % and the Te atoms in 15 atom %-58 atom %, thus obtaining a preferable recording property having a high C/N ratio and a small jitter in a wide power margin in recording and reproducing information having a small b/d ratio (a ratio of a recording bit length b for a spot diameter d).

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 line 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 reflection 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: This invention provides an optical recording-reading device that prevents deterioration of the recorded signals on the optical recording medium caused by the optical beam, and the optical recording-reading device can store information safely. An optical recording-reading device comprises an optical head to produce an optical beam, a transfer board to move the optical beam, and a motor that rotates a disk optical recording medium having a recording thin film which changes its state due to the irradiation of the optical beam. Recording and reading are conducted at a relative velocity between the optical beam and the optical recording medium that is determined as a substantially constant linear velocity. The optical recording-reading device has a transfer control unit to control the movement of the optical beam, and rotation rate control unit to control the rotation rate of the optical recording medium.

Abstract: An apparatus for writing on and reading an overwritable optical disk comprises an identifier detector that identifies a recording condition in the sector to be overwritten, and a delay time controller circuit that sets a variation range of the start point for writing according to the recording condition. The record timing of the modulated data signal is changed at random within the set variation range when overwriting the sector of the optical disk.

Abstract: An apparatus for writing on and reading an overwritable optical disk comprises an identifier detector that identifies a recording condition in the sector to be overwritten, and a delay time controller circuit that sets a variation range of the start point for writing according to the recording condition. The record timing of the modulated data signal is changed at random within the set variation range when overwriting the sector of the optical disk.

Abstract: An apparatus for writing on and reading an overwritable optical disk comprises an identifier detector that identifies a recording condition in the sector to be overwritten, and a delay time controller circuit that sets a variation range of the start point for writing according to the recording condition. The record timing of the modulated data signal is changed at random within the set variation range when overwriting the sector of the optical disk.