Ricoh Company, Ltd.

Masaki Katoh

Yuki Nakamura

Katsuyuki Yamada

A recordable optical information recording medium having an address t for each sector, comprises: an area Astarting from an address tto which access is made only when a recording apparatus performs recording operation; an area Astarting from an address tto which access is made either when the recording apparatus performs the recording operation or when the recording apparatus performs reproducing operation; and an area Astarting from an address tto which access is made either when either the recording apparatus or a reproducing apparatus performs recording or when either the recording apparatus or the reproducing apparatus performs reproducing. The addresses t are set consecutively with respect to a physical arrangement of the sectors in each of the areas Aand A, and the area Ahas at least one inconsecutive part at which the addresses t are not consecutive with respect to the physical arrangement of the sectors.

Optical information recording medium and recording apparatus

A phase change optical recording medium includes at least a supporting substrate and a recording layer essentially consisting of AgInSbTe alloy compositions implementing recording and readout steps utilizing changes in reflectivity. The recording medium is characterized by the relation v&#x2267;0.7 v, where the critical relative velocity of phase change, v, defined by the value of v, at which the differential coefficient, &#x2212;dR/dv, reaches a maximum, when the recording medium moves against an optical unit during the recording steps at a relative velocity, v, ranging from minimum and maximum relative velocities warranted for the recording medium, vand v, respectively. When the reflectivity is measured with varying erase power Pat the linear relative scanning velocity v, the reflectivity of the recording layer as a function of erase power, R(P), preferably has a minimum. The recording layer has an activation energy of deterioration equal to or greater than 1.6 eV, which is obtained by measuring asymmetry, A, and calculating according to the equations, k=dt/dA, and k=k&#xd7;exp(E/kT). The recording medium is also characterized by activation energy of displacement of the boundary, ranging from 1.0 eV to 2.4 eV, which is obtained from the rate of decrease in the area, S, of the amorphous regions as recorded marks with time according to Arrhenius' equation.

Optical information recording medium

A recordable optical information recording medium having an address t for each sector, comprises: an area Astarting from an address tto which access is made only when a recording apparatus performs recording operation; an area Astarting from an address tto which access is made either when the recording apparatus performs the recording operation or when the recording apparatus performs reproducing operation; and an area Astarting from an address tto which access is made either the recording apparatus or a reproducing apparatus performs recording or when either recording apparatus or the reproducing apparatus performs reproducing. The addresses t are set consecutively with respect to a physical arrangement of the sectors in each of the areas Aand A, and the area Ahas at least on inconsecutive part at which the addresses t are not consecutive with respect to the physical arrangement of the sectors.

Optical information recording medium, with at least one inconsecutive part, and recording apparatus

Optical recording apparatus for recording addresses and having a non-consecutive part in which addresses may or may not be set

The phase-change type optical information recording medium includes a transparent substrate, a first protective layer on the substrate, a recording layer on the first protective layer, a second protective layer on the recording layer, and a reflective layer on the second protective layer. Assuming that minimum recording linear velocity is Vand maximum recording linear velocity is V, then a value of ratio I(V)/I(V) of a degree of modulation corresponding to the maximum and minimum linear velocities is between 1 and 1.2.

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Kanagawa, Japan

Masaki Katoh