摘要:
An optical recording medium such as DVD has a data recording area (103) in which data can be rewritten and a write-once area (104) in which data can be written only once and not be erased. A medium specific ID (105) which is specific to an optical recording medium is recorded in the write-once area (104). In the data recording area (103), a reflectance ratio of a part where the data is recorded is different from a reflectance ratio in a part where the data is not recorded. A reflectance ratio of a recording pit formed in the write-once area (104) is higher than the higher one of the reflectance ratios in the part where the data is recorded and in the part where the data is not recorded in the data recording area (103). Data recoding in the write-once area (104) is performed by irradiating to the write-once area (104) a laser beam with heat amount of three to 25 times heat amount necessary for recording rewritable data in the data recording area (103).
摘要:
On a substrate, a recording layer which reversibly transforms between two states with different optical properties--a crystalline phase and an amorphous phase--by the irradiation of a laser beam, a first and a second dielectric layer on the bottom and the top surfaces of the recording layer, and a third dielectric layer on one surface of the first or the second dielectric layers and on the opposite side with respect to the recording layer are successively laminated, thus preparing an optical information recording medium. The third dielectric layer has a smaller coefficient of thermal expansion than the first and the second dielectric layers, so that the thermal deformation of the first and the second dielectric layers is reduced and the mass transfer of the recording layer is controlled. As a result, the overwrite cycle characteristics of the optical information recording medium are excellent.
摘要:
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.
摘要:
A method of manufacturing an optical information recording medium comprising the steps of: forming a plurality of component thin films on a substrate or on a sample at a predetermined film-forming speed and within a predetermined film-forming time in sequence; measuring spectral reflectance of the multilayer thin film formed on the substrate or on the sample; comparing the measured value of the spectral reflectance and the standard value of the spectral reflectance to detect the difference between them; compensating at least one of the film-forming speed and the film-forming time based on the detected difference; and forming a plurality of thin films based on the compensated film-forming speed and with the compensated film-forming time. Consequently, a thickness of each component thin film of the optical information recording medium can be measured easily and production loss in measuring a film-forming speed can be decreased.
摘要:
On one surface of a disk substrate, a first dielectric layer, a thin recording layer, a second dielectric layer and a reflecting layer are cumulatively formed. The second dielectric layer is thinner than the first dielectric layer and is 35-70 nm thick. The reflecting layer is 70-120 nm thick. The total thickness of the four layers is 250-430 nm. The compressire stress of the layers is offset by tensile stress generated by an overcoat resin protective layer, formed on the reflecting layer. A method of using the optical recording medium applies the MCAV (Modified Constant Angular Velocity) recording method which records information by changing recording frequencies in accordance with linear velocity. The linear velocity is 5-12 m/s. A ratio of an inner circumference recording pulse width to an outer circumference recording pulse width is 1.2 or more.
摘要:
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.
摘要:
A method for recording information on an optical information recording medium 1, 11 having a plurality of recording layers for recording, reproducing or erasing data by irradiating a laser beam from one side, includes a temporary pulse condition determination step (S502), a test area reflected light measurement step (S502), a final pulse condition determination step (S503-S506) and a recording execution step (S506). The temporary pulse condition determination step includes performing test recordings on a test recording layer that is at least one recording layer among a plurality of recording layers and determining a temporary pulse condition including a laser beam intensity. The test area reflected light measurement step includes measuring a test area reflected light level that is a reflected light level of the laser beam in an area for the test recording. The final pulse condition determination step includes correcting the temporary pulse condition in accordance with the measured test area reflected light level so as to determine a final pulse condition. The recording execution step includes recording data with the final pulse condition.
摘要:
An optical information recording medium according to the present invention includes at least one groove track and at least one land track allowing information to be recorded on or reproduced from the groove track and the land track, the groove track and the land track adjoining each other. The optical information recording medium further includes: an identification signal region including a pre-pit array, the pre-pit array indicating identification information concerning the groove track and the land track; and a servo control region disposed ahead of the identification signal region along the groove track and the land track, the servo control region including wobble pits positioned so as to shift to opposite sides of a center line of either the groove track or the land track.
摘要:
A substrate for an optical recording medium, includes recording tracks formed in guide grooves on a disc; and an address section having an address pit sequence formed between the recording tracks in the guide grooves along an information reading direction of the recording tracks. The recording tracks in the guide grooves are divided into a prescribed number of zones. In each of the zones, the center of the address section corresponding to a recording track in the radially outermost or radially innermost guide groove is disposed so as to shift in a radial direction of the disc in relative relationship to the center of the recording track in the guide groove.
摘要:
On one surface of a disk substrate, a first dielectric layer, a thin recording layer, a second dielectric layer and a reflecting layer are cumulatively formed. The second dielectric layer is thinner than the first dielectric layer and is 35-70 nm thick. The reflecting layer is 70-120 nm thick. The total thickness of the four layers is 250-430 nm. The compressive stress of the layers is offset by tensile stress generated by an overcoat resin protective layer, formed on the reflecting layer. A method of using the optical recording medium applies the MCAV (Modified Constant Angular Velocity) recording method which records information by changing recording frequencies in accordance with linear velocity. The linear velocity is 5-12 m/s. A ratio of an inner circumference recording pulse width to an outer circumference recording pulse width is 1.2 or more.