摘要:
An information recording method and apparatus therefor utilizes an information recording medium having a recording film enabling reversible phase change. The information recording medium is irradiated with an energy beam while relatively moving the information recording medium and the energy beam so as to at least enable recording of information in accordance with phase state changes of the recording film caused by irradiation of the energy beam. The energy beam is modulated so that an intensity of the energy beam obtains a first level having a high power for one portion of coded data information to be recorded, obtains a second level different from the first level for a predetermined time for another portion of the coded data information, and then again obtains the first level to enable recording of the coded data information independently of a previous recording state on the information recording medium.
摘要:
An optical information recording carrier which comprises an information recording film susceptible to a change in atomic arrangement upon exposure to a recording beam, a first transparent film for preventing diffusion of heat generated in the recording film upon exposure to the recording beam and provided on each side of the recording film, a second transparent film for diffusing the heat in the in-plane direction of the film and provided on at least one outside thereof, and an organic member further provided on at least one outside thereof, the recording beam being irradiated onto the recording film through the organic member has distinguished characteristics of repeated recordings and erasings.
摘要:
A separation type optical head according to the present invention includes at least a light source portion for emitting collimated beams, a focusing device (a focusing lens) for focusing the collimated beams onto an information recording surface of an optical disc medium, a focal point control mechanism for the position of the spot on the information recording surface, and a photo-detection portion for receiving beams reflected by the information recording surface. The structure is divided into a fixed portion including the light source portion and the photo-detection portion and a movable portion including the focusing device (focusing lens) and the focal point control mechanism. At least the movable portion of the separation type optical head is movably accommodated n a frame (sealing case) for the optical head so as to prevent irregular vibrations of the movable portion due to high speed air flows or turbulence. Furthermore, a focal point control mechanism of an air float type may be employed in the movable portion of the separation type optical head so as to actively utilize the high speed air flow generated due to the rotation of the disc medium to perform a rough adjustment of the focal point of the focusing device.
摘要:
In an information recording apparatus according to this invention, since it is not necessary to dispose any differential circuit, which was required heretofore, it is possible to fabricate it with a low cost and its error rate is also very small.Furthermore, since the mean reflectivity on the recording track does almost not vary by the fact that information is recorded there, no tracking off-set or focusing off-set is produced. Thus effects of this invention are remarkable.
摘要:
According to this invention, since the range of power necessary for erasing an overwritable magneto-optical recording medium is set to 2.5 mW or above, overwriting is possible without erase residue due to mark (magnetic domain) diameter difference, tracking offset, ambient temperature variation and characteristic dispersion between magneto-optical recording media and thus the magneto-optical recording medium has high reliability. Moreover, the rate of change, K of the switching field of the memory layer relative to temperature at around an erase start temperature can be controlled to be a constant value so that an erase power margin can be increased and that the tolerance to the reading light when the ambient temperature rises can be improved.
摘要:
A magneto-optical recording medium comprising, on a substrate, at least a first magnetic layer made of a rare earth amorphous alloy and a second magnetic layer made of a rare earth amorphous alloy having a relatively smaller coercivity Hc.sub.2 than that of the first magnetic layer, wherein the following relationship is satisfied at an operation temperature:Hw.sub.1 -Hexc.sub.1 >Hc.sub.2 -Hexc.sub.2where Hw.sub.1 represents the magnetic domain wall coercivity of the first magnetic layer, Hexc.sub.1 represents the magnitude of the exchange magnetic field exerted on the first magnetic field and Hexc.sub.2 represents the magnitude of the exchange magnetic field exerted on the second magnetic layer is used, to obtain a magneto-optical recording medium with no increase in the noises by overwriting, and without reduction of C/N ratio after repeating recording for a number of cycles, a recording method and overwriting method using the media and a magneto-optical recording device.
摘要:
This invention provides a magneto-optical recording medium comprising at least an information storage layer and a readout layer disposed on the substrate, the information storage layer being used to record information by changing the magnetized state by raising the temperature thereof by light irradiation, and the readout layer being capable of copying information recorded on the above-mentioned information storage layer, located closer to the substrate than the above-mentioned information storage layer, and having a coercive force of 3 kOe or less at room temperature. By using this recording medium, a Signal to Noise ratio can be obtained in reproduction without deterioration of the information recording characteristics.
摘要:
A desired portion of information stored in the form of holes using hole burning phenomena is erased by irradiating a desired portion of a recording medium with light so as to erase desired holes. In this way it is possible to erase selectively only desired information among information stored in a PHB memory and further to rewrite information in the portion, where information has been erased.
摘要:
A recording member in which a bismuth-antimony alloy thin film containing antimony as its indispensable component is deposited on a predetermined substrate is disclosed. The Sb content of the film lies in a range of from 1 % to 15 % inclusive in terms of the average atomic-%. Preferably, the Sb content has the average value held in the specified range, and it is gradually increased in the thickness direction of the film so that in the part near the substrate and/or front surface of the film, the maximum content may lie within a range of at most three times the average content of other part of the film.
摘要:
A recording member having a predetermined substrate, and a thin film which is formed on the substrate and which is formed with recesses or pits for recording information when irradiated with a working beam, characterized in that said thin film is formed of an inorganic material which contains at least arsenic, selenium and tellurium, and that a distribution of either of said Se and said Te decreases from a part near the surface of said thin film towards a central part thereof, while a distribution of said As increases from a part near the surface towards said central part, is disclosed. This recording member can afford a high signal-to-noise ratio and a long lifetime. It is preferable that the distribution of said Se decreases so as to be at least 50 atomic-% in terms of the content of said Se in a part being the closest to the surface of said thin film and to be at most 40 atomic-% in terms of the average content of said Se over the whole thin film, and that the distribution of said As increases so as to be at most 15 atomic-% in terms of the content of said As in the closest part and to be 5 to 35 atomic-% in terms of the average content of said As in said whole thin film. The Se-Te-As-based material may well be doped with at least one element selected from the group consisting of Ge, S, Tl, Sn, Pb, In and Ta, within a range of 2 to 15 atomic-%.