568results about "Optical overwriting" patented technology

In a phase-change recording medium, a recording medium is provided with a barrier layer including Ge-N, Ge-N-O between a recording layer and a dielectric protective layer in order to prevent a chemical reaction and an atom diffusion between the recording layer and the dielectric protective layer. A barrier material can be also applied to the protective layer itself. Thereby, it is possible to considerably suppress a reduction of a reflectivity and a reduction of a signal amplitude due to the repeat of recording and erasing, such reductions being observed in a conventional phase-change optical information recording medium, and thereby the number of overwriting times can be increased.

An optical disk recording method includes the steps of: providing a multi-pulse chain from a recording wave; independently changing the pulse rise timing and pulse fall timing (pulse width) of the first pulse in the multi-pulse chain in accordance with a preceding space length and a recording mark length; changing the pulse rise timing and pulse fall timing (pulse width) in accordance with a following space length and the recording mark length in a predetermined timing or in independence; and in relation to the smallest mark recorded by irradiation with mono pulse, changing the rise timing in accordance with the preceding space length and the recording mark length and the fall timing (pulse width) in accordance with the following space length and recording mark length, compensating various optical disks different in recording material without change of the fundamental waveform.

In an optical disc in/from which data is recorded or reproduced by irradiating a storage area on the optical disc with a laser, information containing recording velocity information (RVI) for recording/reproduction, which represents a linear velocity different from the standard linear velocity, and write strategy information (WSI) corresponding to the recording velocity information is stored in a land pre-pit or the like on the optical disc.

A method of recording and reproducing information in a phase-change optical recording medium by irradiation of an electromagnetic wave for recording, reproducing and/or rewriting information is proposed, wherein when information is recorded in the phase-change optical recording medium by modulating an input signal and conducting pulse width modulation recording, a recording pulse string for recording and rewriting is a continuous electromagnetic wave, and a recording pulse string for input signal, is an electromagnetic wave pulse string having a front-pulse portion fp, a multi-pulse portion mp with a total pulse duration period T and a duty ratio y, and an off-pulse portion op, wherein the duty ratio y is decreased as a recording linear velocity for the phase-change change optical recording medium is increased, whereby multi-speed recording or CAV (constant angular velocity) recording is carried out. An information recording and reproducing apparatus, using the above method, is also proposed.

An optical phase-change disc comprises a substrate having thereon a spiral groove or concentric grooves for guiding a focused light beam, and a layer structure including a recording layer and protective layers sandwiching therebetween the recording layer. The groove has wobble for recording ATIP (absolute time information) or ADIP (address information). The following relationship between the groove width GW, beam diameter R0 and wobble amplitude aw: 0.25</=GW/R0</=0.45 or 0.65</=GW/R0; and 0.03</=aw/GW</=0.08 hold for preventing distortion of the groove caused by repeated overwriting operation to improve reliability of the optical disc.

Good jitter is retained and recorded even when a linear velocity is variable. A recording parameter suitable for each of the linear velocities is obtained by performing test writings for an outer periphery zone of a disc at different linear velocities, and based on a correlation between each of the linear velocities and a recording parameter suitable for each of the linear velocities, a recording parameter corresponding to a linear velocity on an area onto which information is to be recorded is obtained.

The present invention is directed to an optical information recording medium on which parameters of a plurality of multipulse pattern each having a different applied liner velocity ranges and information regarding recordable liner velocities capable of recording with each of the multipulse patterns are pre-formatted as recording conditional information. The present invention is also directed to an optical information recording apparatus capable of reading pre-formatted information from the optical information recording medium, comparing the pre-formatted information and the specification of the apparatus and selecting an optimum recording condition from the result of comparing. The present invention further relates to a method for determining a recording condition using the optical information recording medium and/or the optical information recording apparatus, and an information processing apparatus disposing the optical information recording apparatus therein.

A silver-based alloy thin film is provided for the highly reflective or semi-reflective coating layer of optical discs. Elements that can be added to silver to produce useful silver alloys include zinc, aluminum, copper, manganese, germanium, yttrium, bismuth, scandium, and cobalt. These alloys have moderate to high reflectivity and reasonable corrosion resistance in the ambient environment.

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).

There is provided an optical recording method for directing a recording pulse train to an optical disc medium to form marks thereon and for recording information as information about the edge positions of said marks and the spaces between marks, the recording pulse train having been created by modulating laser light into plural power levels. The method includes: coding to-be-recorded data into coded data consisting of the combination of marks and spaces; classifying said marks within said coded data on the basis of the mark length and the preceding or succeeding space lengths of the marks; shifting the position of the second pulse edge counted from the end portion of the recording pulse train for forming said marks, depending on the result of said classification, to adjust said recording pulse train; and directing said recording pulse train to the optical disc medium to form said marks thereon.

An optical recording method that performs recording by irradiating optical recording media with laser beam modulated in intensity based on a write waveform is provided. The write waveform has a plurality of write pulse blocks for forming write marks, and each write pulse block has at least one type of upward pulse. In the event that the width of said upward pulse is so narrow that the laser beam intensity corresponding to the peak intensity of that upward pulse cannot be obtained, the peak intensity of that upward pulse is increased so that, in said laser beam, the beam intensity it should have or a value close thereto is obtained. Thereby, good recording and playback characteristics can be obtained even when recording at a high transfer rate.

The present invention provides an optical information recording apparatus and method capable of effectively determining appropriate recording parameters in a short time with favorable efficiency, when recording information onto an optical disk having different information recording conditions and information recording characteristics. An information recording condition or an information recording characteristic of an optical disk 1 is identified, and a recording pulse position is corrected at a correction accuracy according to the identifies information recording condition or information recording characteristic, such that a recording mark is formed in a predetermined position.

An information storage medium (1) has tracks in which information is recorded. The tracks are formed as a groove section (2) and a land section (3). The groove section (2) has a synchronous structure in which wobbles (2a) and (2b) formed on both walls of the groove section (2) are not displaced from each other in the circumferential direction of the medium, and the land section (3) has an asynchronous structure in which wobbles formed on both sides of the land section (3) are displaced from each other. A good signal is reproduced from each of the groove and land sections.

A shortest mark 108 is recorded with a single recording pulse. A long mark 125 is recorded with a two-stage pulse including a first-part pulse and a second-part pulse. In the case where each of positions 115 and 118 of front edges of the recording pulses is determined based on a relationship between a length of a space immediately before a mark and that of the mark itself so as to properly position the front edges of reproduced waveforms of all the mark lengths and each of positions of rear edges of the recording pulses of all the mark lengths is fixed so as to satisfy a prescribed relative relationship with an edge of a recording clock, power 122 of a recording pulse 101 of the shortest mark is determined so as to realize a proper rear edge position 112 of the reproduced waveform of the shortest mark and power 124 of a second-part pulse 104 is determined for each mark length so as to realize a proper rear edge position 123 of the reproduced waveform of the long mark.

A method of recording data capable of preventing an adjacent track erase is provided. The method includes accumulating and computing the number of times the data is recorded in sectors of at least one track, determining whether the accumulated number of times exceeds a predetermined number of times, and rewriting the data, which is recorded in adjacent tracks to the at least one track, in the adjacent tracks, if the accumulated number of times exceeds the predetermined number of times. If the number of times exceeds a predetermined number, the data is rewritten in regions adjacent to the specific region, thereby minimizing the influence of the ATE.

A mark having a length nT (n being an integer equal to or greater than 3 and T being a clock period) is formed by modulating irradiation laser power with three values of recording power Pw, erase power Pe, and bias power Pb (Pw>Pe>Pb). Constant strength periods (A_t) of the recording power Pw are set as A_tT, A₁T, . . . and A_mT and constant strength periods (B_t) of the bias power Pb are set as B_tT, B₁T, . . . B_mT, and CT (C=−1 to 3). The application of laser is divided into pulses in order of A_tT, B_tT, A₁T, B₁T, . . . , A_mT, B_mT, and CT (m=(n−k)/2, k=3 (if n is an odd number), or k=4 (if n is an even number)). (Here, the constant strength period of the recording power Pw for n=3, n=4, n≧5 (odd number), and n≧6 (even number) is set as A_t3, A_t4, A_tod, and A_tev, the constant strength period of the bias power Pb for n=3, n=4, n≧5 (odd number), and n≧6 (even number) is set as B_t3, B_t4, B_tod, and B_tev, and then, A_t3+B_t3=A_tod+B_tod=A_m+B_m=2T and A_t4+B_t4=A_tev+B_tev=3T).

To provide an optical recording method to be used for recording at a high data transfer rate where the reference clock frequency is at least about 200 MHz and a linear velocity is about 40 m/sec.

When recording mark length-modulated information is to be recorded on a recording medium by applying a recording laser beam locally to the recording medium, in order to form one record mark length of nT, m pieces of recording pulses α_iT (1≦i≦m) and m pieces of off-pulses β_iT (1≦i≦m), represented by:

α₁T, β₁T, α₂T, β₂T, . . . , α₁T, β₁T, . . . , α_mT, β_mT

(where m is a natural number representing a pulse dividing number, α_i (1≦i≦m) is a real number of larger than 0, β_i (1≦i≦m-1) is a real number of larger than 0, and β_m is a real number of at least 0), are used, and a recording laser beam having a writing power Pw_i is applied within a time of α_iT (1≦i≦m), a recording laser beam having a bias power Pb_i of Pb_i<Pw_i and Pb_i<Pw_i+1, is applied within a time of β_iT (1≦i≦m-1), the front recording pulse α₁T will rise as deviated for a time of dT_top from the front position of the record mark having a length of nT, with respect to at least two record marks, the pulse dividing number m is at least 2, and with respect to all record marks with m being at least 2, 2.5≦n/m, in a case where plural different record mark lengths are to be respectively formed by the same pulse dividing number m, α₁ and/or α_m is changed to form such record mark lengths having different lengths respectively, provided that when the α₁ is changed, dT_top and/or β₁ is also changed, and when the α_m is changed, β_m-1 and/or β_m is also changed.

A high-speed optical disc recording apparatus includes a laser diode for generating multi-pulse light pulses and a photodiode outputting a measured power of the light pulses. An NRZI pattern encoder generates a predetermined power control pattern causing a write strategy generator to generate write strategy to a laser diode driver such that the laser diode outputs a multi-pulse having a fixed-duty ratio with two power levels. The measured power is averaged with a low-pass filter, is sampled and held, and is calibrated according to the fixed-duty ratio. The calibrated held average output of the measured power of the light pulses is compared with predetermined present levels to control the laser diode driver output voltage.

In a rewritable compact disc having a wobble groove on a substrate, crystal and amorphous states of a phase-change recording layer are an unrecorded/erased state and a recorded state, respectively. When the recording layer is exposed to recording light, amorphous marks assuming the recorded state are formed. At any of 2-, 4- and 8-times velocities with respect to a reference velocity (1-times velocity) whose linear velocity is 1.2-1.4 m/s, modulation m11 of a recorded signal when the recording light of approximately 780 nm in wavelength irradiates the recording layer via an optical system with NA=0.5 or 0.55 is 60-80%. A topmost level Rtop of reflectivity of the eye pattern of the recorded signal during retrieving at the 1-times velocity is 15-25%, and a jitter of the individual length of marks and inter-mark spaces during retrieving at 1-times velocity is 35 ns or less. Recording at 8-times or higher velocities is thereby realized without any risk of impairing the read-compatibility with the conventional CD-RW specifications at least at 4-times velocity.

An optical recording apparatus can maintain an excellent recording quality. A recording quality is evaluated when recording information on an optical disc Test recording is performed on a predetermined test area, when recording strategy information corresponding to the optical disc is unknown, based on default recording strategy information. The recording quality is evaluated by reproducing data recorded on the test area.

A data recording method according to the present invention is a method for recording data as edge position information, including marks and spaces of multiple different lengths, on a storage medium by irradiating the storage medium with a pulsed energy beam. The method includes the steps of: (A) generating a NRZI data based on the data to be recorded; (B) determining a write pulse waveform, defining the power modulation of the energy beam, according to the code lengths of respective codes included in the NRZI data; and (C) modulating the power of the energy beam based on the write pulse waveform. If the shortest code length of the NRZI data is n (which is an integer equal to or greater than one), a write pulse waveform that has only one write pulse is assigned to recording mark making periods corresponding to codes with code lengths x of n, n+1 and n+2, and a write pulse waveform that has multiple write pulses Pw is assigned to recording mark making periods corresponding to codes with code lengths x of n+3 or more.