Back to results
US 2004/0170115 A1Published application
Optical recording medium
AssigneeTDK Corporation
InventorsHiroyasu Inoue, Hideki Hirata
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeTDK Corporation
InventorsHiroyasu Inoue, Hideki Hirata
Estimating the term…
An optical recording medium is provided, which has reduced degradation in jitter caused by manufacturing variations of a semiconductor laser emitting laser beams or variations in output power of laser beams, and which dissipates heat in the recording layer during recording by laser beams to increase the power margin of the laser beam providing playback jitter values at a certain level or less. An optical recording medium 10 has a support substrate 12, on which formed are a reflective film 16, a second dielectric layer 18, a recording layer 20, a first dielectric layer 22, a heat sink layer 24, and a light-transmitting layer 26. The heat sink layer 24 is formed of a material having a thermal conductivity within a certain range, e.g., alumina, to dissipate heat through the heat sink layer 24 when the heat is generated by a laser beam incident from the light-transmitting layer 26, thereby preventing an increase in temperature of the recording layer 20.
An optical recording medium, having at least a light-transmitting layer covered with a recording layer formed on a support substrate, for recording information on the recording layer by a laser beam incident from the light-transmitting layer, wherein the recording layer is provided with a heat sink layer on its light-transmitting layer side, the heat sink layer being made of a material having a thermal conductivity of greater than 1 W·m−1·K−1.
An optical recording medium, having at least a recording layer, for recording information by forming a recording mark on the recording layer with a laser beam, wherein a condition of Pw(max1)/Pw(min1)>2.2 is satisfied, where Pw(min1) is a lower limit of recording power provided by the laser beam when a jitter value of the recording mark formed is less than 13%, and Pw(max1) is an upper limit of recording power provided by the laser beam when the jitter value of the recording mark formed is less than 13%.
An optical recording medium, having at least a recording layer, for recording information by forming a recording mark on the recording layer with a laser beam, wherein a condition of Pw(max1)/Pw(min1)>2.2 is satisfied, with the laser beam having a wavelength of 450 nm or less and an objective lens for focusing the laser beam being designed to have a numerical aperture of 0.7 or more, where Pw(min1) is a lower limit of recording power provided by the laser beam when a jitter value of the recording mark formed is less than 13%, and Pw(max1) is an upper limit of recording power provided by the laser beam when the jitter value of the recording mark formed is less than 13%.
Dependencies are inferred from the claim text.