Abstract: In a data recording and readingout system in which data is recorded and readout, or is readout on, or from an optical recording medium 1 by irradiating a laser beam having a wavelength “?” via an objective lens of a numerical aperture “NA” onto said optical recording medium, while the optical recording medium contains a layered structure formed by sandwiching a dielectric layer 6 between a recording layer 7 and an optical absorption layer 5, with respect to the optical recording medium 1 arranged in such a manner that data recorded by a recorded mark train can be readout and the recorded mark train contains a recorded mark smaller than, or equal to a limit of resolution, the laser beam is irradiated via the objective lens and a solid immersion lens having a refractive index “n” which is positioned between the optical recording medium and the objective lens, so that the data is recorded and readout, or is readout with respect to the optical recording medium by a recorded mark train which contains a recorded ma

Abstract: An optical recording medium capable of both recording in conformity to BD standard and recording/reading in conformity to DVD or CD standard. The optical recording medium includes: at least one recording layer located in the range of 40 to 120 ?m away from a light incident surface, the recording layer having a light absorption characteristic which enables write-once recording using a laser optical system having a wavelength in the range of 400 to 410 nm and a numerical aperture in the range of 0.80 to 0.90 and having a light absorption characteristic which disables write-once recording using a laser optical system having a wavelength in the range of 620 to 660 nm and a numerical aperture in the range of 0.55 to 0.

Abstract: When the recording capacity of an optical recording medium is increased, both reproduction characteristics and a tilt margin are improved. Specifically, when a laser beam is projected onto an information recording layer of the optical recording medium to reproduce information, a laser beam having a wavelength of 400 to 410 nm is employed. In addition, an objective lens which converges the laser beam and has a numerical aperture NA of 0.70 to 0.90 is employed. The reproduction is started by projecting the laser beam. A reproduction signal obtained by projecting the laser beam is decoded by means of a PRML detection method to generate reproduction data of the optical recording medium. When the quality of the reproduction data deteriorates, the power of the laser beam is temporarily increased.

Abstract: A super resolution optical reproducing system, which can recognize a recording mark less than a resolution limit, removes the effect of a high-frequency noise component of a high power signal obtained by irradiating a laser beam with high read power. The same recording region of an optical recording medium is irradiated according to an irradiation spot by a laser beam with an ordinary read power and an irradiation spot by a laser beam with high read power to obtain a ordinary power signal and a high power signal. The ordinary power signal and the high power signal are normalized to an average level by high pass filters and low pass filters of a high power signal processing circuit and a ordinary power signal processing circuit. Then, a subtracter subtracts the ordinary power signal from the high power signal to obtain a substrated signal.

Abstract: In a data recording and readingout system in which data is recorded and readout, or is readout on, or from an optical recording medium 1 by irradiating a laser beam having a wavelength “?” via an objective lens of a numerical aperture “NA” onto said optical recording medium, while the optical recording medium contains a layered structure formed by sandwiching a dielectric layer 6 between a recording layer 7 and an optical absorption layer 5, with respect to the optical recording medium 1 arranged in such a manner that data recorded by a recorded mark train can be readout and the recorded mark train contains a recorded mark smaller than, or equal to a limit of resolution, the laser beam is irradiated via the objective lens and a solid immersion lens having a refractive index “n” which is positioned between the optical recording medium and the objective lens, so that the data is recorded and readout, or is readout with respect to the optical recording medium by a recorded mark train which contains a recorded ma

Abstract: The optical recording medium of the present invention is a phase change optical recording medium which can be used as a write once medium and which can be recorded at a high recording density. The optical recording medium of the present invention is adapted for recording such that, when the recording beam has a wavelength of ?, and objective lens of recording optical system has a numerical aperture of NA, minimum record marks formed are circular or ellipsoidal marks having a length of 0.4 ?/NA or less; and the medium is a write once medium wherein the recorded information can not be erased or rewritten at the minimum linear velocity used.

Abstract: It is an object of the present invention to provide an inspection method for judging whether or not a phase change type medium can be used as a write-once type medium.

Abstract: The optical recording medium of the present invention is a phase change optical recording medium which can be used as a write once medium and which can be recorded at a high recording density. The optical recording medium of the present invention is adapted for recording such that, when the recording beam has a wavelength of &lgr;, and objective lens of recording optical system has a numerical aperture of NA, minimum record marks formed are circular or ellipsoidal marks having a length of 0.4&lgr;/NA or less; and the medium is a write once medium wherein the recorded information can not be erased or rewritten at the minimum linear velocity used.

Abstract: In a phase change optical recording medium, time required for recording the unrecorded area as well as jitter produced are reduced. Provided is an optical recording method for recording an optical recording medium having a phase change recording layer, wherein the recording is conducted such that: VW/Vo>1, and 0.

Abstract: In a phase change optical recording medium, time required for recording the unrecorded area as well as jitter produced are reduced. Provided is an optical recording method for recording an optical recording medium having a phase change recording layer, wherein the recording is conducted such that: VW/Vo>1, and 0.

Abstract: An optical recording medium adapted for high density recording with a light of short wavelength which exhibits excellent jitter properties, and its recording method are provided. The optical recording medium recorded and/or reproduced with a light at a wavelength of 600 to 680 nm comprises a substrate having grooves formed on its surface at a track pitch of up to 0.8 .mu.m, and a recording layer containing an organic die disposed on the substrate. Depth A and width B of the groove (.mu.m) and leveling ratio C are in the relation:0.035.ltoreq.A.times.B.ltoreq.0.06, and2.ltoreq.C/A.ltoreq.3.5when the leveling ratio C is represented by the following formula (I):leveling ratio=[thickness of the recording layer on the groove (.mu.m)-thickness of the recording layer on the land (.mu.m)]/[depth of the groove (.mu.

Abstract: In an optical recording disk comprising a reflective layer in close contact with a recording layer, the recording layer contains a phthalocyanine dye and a second dye having a lower heat decomposition temperature than the phthalocyanine dye. By virtue of a depression of heat decomposition temperature, recording sensitivity is improved.

Abstract: With a dye recording layer having an index of refraction n of 2.0 to 2.6 formed on a substrate, that portion of the recording layer disposed in a groove is used as a recording track by restricting the groove to a width W.sub.G of 0.38 to 0.45 .mu.m and a depth D.sub.G of 1000 to 1700 .ANG. and that portion of the recording layer in the groove to a thickness T.sub.G of at least 2000 .ANG. for 2.0.ltoreq.n.ltoreq.2.3 or to W.sub.G of 0.38 to 0.45 .mu.m, D.sub.G of 1000 to 2300 .ANG., and T.sub.G of at least 2500 .ANG. for 2.3<n.ltoreq.2.6. Reproduction is performed by means of a CD player which is adapted to perform tracking control by detecting a tracking error signal by the differential phase technique. There is obtained a tracking control loop gain of -2 dB or higher relative to that of commercially available CD, ensuring stable and accurate tracking control.

Abstract: In an optical recording medium comprising an organic dye base recording layer and a reflective layer on a resin substrate having a groove of 1,100 to 2,300 .ANG. deep formed in one surface thereof, signals are written by directing recording light to the recording layer within the groove from the back side of the substrate at a relative linear velocity of at least 3.6 m/s whereby record marks are formed in the recording layer as a result of partial decomposition of the dye while deforming the groove bottom surface. The deformation of the groove bottom surface is minimized to less than 18% of the groove depth. The medium requires a short time for recording and offers reduced jitter on reproduction.

Abstract: An optical recording disk includes a dye base recording layer, an intermediate layer, and a reflective layer on a substrate in the described order. The reflective layer is composed of one or more metal elements, for example, copper alloy, and the intermediate layer contains a compound of the one metal element or a compound of at least one of the metal elements, for example copper oxide. The intermediate layer minimizes undesirable interactions between the recording and reflective layers.

Abstract: An optical recording disk includes on a substrate 2, a dye recording layer 3, a lower reflective lamina 4, an upper reflective lamina 5, and a protective coat 6. The lower reflective lamina 4 is formed of Au, Pt, Ag, Al or an alloy thereof and the upper reflective lamina 5 is of a stainless steel composition or an alloy containing 30 wt % or more of Cu and at least one element selected from the group consisting of Zn, Ti, V, Ta, Cr, Mo, W, Mn, Fe, Co, Rh, Ni, Pd, Pt, Ag, Au, Al, Sn, Si, Pb, Cd, Hg, Ca, In, As, Sb, Bi, Se, Te, Ge, N and O. The disk is well reliable and less costly.

Abstract: In preparing an optical recording disk by spin coating a dye-containing solution to an annular substrate to form a recording layer thereon, a circular channel is preformed in the substrate in proximity to the inner peripheral edge of the substrate for defining an inner boundary of the recording layer. Then the recording layer is free of corrugations near its inner boundary, leading to improved adhesion of an overlying protective film and a minimal variation in reflectivity.

Abstract: In an optical recording disk 1 comprising a dye layer 2 formed on a substrate 3 as a light absorbing layer and a reflective layer 4 stacked thereon, tracking servo control is carried out by the push-pull method. To produce normal and accurate tracking error signals, the surface of the dye layer 2 includes depressed and raised sections corresponding to grooves 31 and lands 35 and .DELTA.D which is given by the formula:.DELTA.D=D.sub.L +d.sub.G -D.sub.Gwherein D.sub.G is the thickness of the dye layer on the groove 31, D.sub.L is the thickness of the dye layer on the land 35, and d.sub.G is the depth of the groove has a higher magnitude than .DELTA.D.sub.0 which is associated with a tracking error signal of zero.

Abstract: An optical recording disk intended for use as an additionally recordable CD is provided. It has a substrate, a dye or recording layer on the substrate, and a reflective layer and a protective layer disposed on the recording layer in a close contact relationship. Recording is carried out by directing recording light to the recording layer to form a pit and reproduction is carried out by directing reproducing light to the pit. A layer containing a decomposition product of the dye or recording material, but substantially free of the substrate material is present at the interface between the substrate and the recording layer where the pit is formed.

Abstract: A pit-forming optical recording medium comprises a substrate supporting a film of optically deformable recording material comprising an organic dye for absorbing optical signals of modulated electromagnetic radiation applied to the film and thereby causing corresponding deformations of the film when the signal intensities exceed predetermined threshold levels. The dye is a phthalocyanine compound or mixture of phtalocyanine compounds in which each of at least five of the peripheral carbon atoms in the 1, 4, 5, 8,9, 12, 13 or 16 positions (the "3,6-positions") of the phthalocyanine nucleus, as shown in Formula I, is linked by an atom from Group VB or Group VIB of the Periodic Table to a carbon atom of an organic radical. In preferred compounds each of the eight 3,6-positions is linked by an atom from Group VB or Group VIB, especially sulphur, selenium or nitrogen, to an organic radical.