Delay signal generator and recording pulse generator

Abstract

A write strategy circuit (recording pulse generator) generates a recording pulse for controlling a laser output applied to an optical disc using data modulated by a DVD encoder or a CD encoder. A delay circuit delays delay subject signals by a predetermined amount to generate delay signals. A delay amount for the delay circuit is controlled by a delay amount control circuit. A logic circuit generates a recording pulse by logically synthesizing the delay signals. The delay amount control circuit includes a voltage controlled oscillator formed by connecting, in a ring-like manner, a plurality of delay elements having the same configuration as the delay elements included in the delay circuit. An output signal of the voltage controlled oscillator is locked at a point where a delay amount for each delay element becomes a fraction of an integer of one cycle of a reference clock signal.