Anderson, Kill & Olick
Laser beam modulation apparatus
 A laser beam modulation apparatus modulates a EFM (eight-fourteen modulated) signal to generate as a laser power control signal a pulse modulated EFM signal (PM-EFM). During each of on-time intervals of the EFM signal, the pulse modulated EFM signal serves to apply the laser beam on a recording area on a phase-change disk and to undulate the laser beam in order to prevent an overheating of the recording area. 
Daewoo Electronics Co., Ltd.
H H G G
H04B H04L G11B G11B
inventional inventional inventional inventional
Jung-Gyu
Kim