US Patent 7529172 Optical disk recording and playback device

An optical disk recording and playback device comprises a first laser driving circuit that supplies a driving signal to a first laser diode, a second laser driving circuit that supplies a driving signal to a second laser diode, a signal recording pulse generating circuit that generates a signal recording pulse signal in accordance with a signal to be recorded on a signal recording layer, and outputs the signal recording pulse signal to the first laser driving circuit, and an image recording pulse generating circuit that generates an image recording pulse signal in accordance with a signal to form an image on an image recording layer, and outputs the image recording pulse signal to the second laser driving circuit. When recording of a signal to the signal recording layer and recording of an image to the image recording layer are simultaneously performed, the first laser diode and the second laser diode are controlled to prevent light emission from simultaneously occurring at recording levels.