The CD-R market has grown rapidly since the development of this media in 19
88. In addition, PC applications have continued to demand ever higher recor
ding speeds. In order to achieve higher speed recording, it is necessary to
reduce thermal interference during the recording process. Higher density r
ecording is subject to the same effects of thermal interference as higher s
peed recording. To directly compare such thermal effects during recording o
n different density disks with different scanning velocities, we introduce
a new parameter. Applying this parameter, it can be clearly demonstrated th
at thermal interference in higher density digital versatile disc-recordable
(DVD-Rs) is approximately equal to that in 4x-speed recording with the low
er density CD-R. Today, the possibility of 4x-speed DVD-R recording has alr
eady been confirmed. It can thus be concluded that write-once organic recor
dable media with a 15 GB capacity per 12 cm diameter disk format is very pr
omising, because the thermal effects associated with the 15 GB recordable m
edia are shown to be equivalent to those in 4x-speed DVD-R.