Optical recording apparatus

An optical recording apparatus for recording information on an associated optical carrier (1), said apparatus comprising:

• processing means (50) arranged for processing an encoded data signal (NRZ), said processing means comprising:
• a first clock generator (52) capable of generating a two-level clock signal (CLK), and
• a duty cycle modulator (MOD) arranged for modulating said clock signal (CLK) in response to the encoded data signal (NRZ) so as to vary the duty cycle of said clock signal (CLK), and outputting a single, combined data and clock signal (NRZ_CLK), and
• an optical pick-up unit (OPU;
• 20) comprising an irradiation source (4) and a corresponding drive device (LDD;
• 22), said optical pick-up unit being operably connected to the processing means (50) for receiving said combined signal (NRZ_CLK), said drive device comprising:
• a second clock generator (24) capable of extracting a retrieved clock signal (CLKr) from the combined signal (NRZ_CLK), and
• a data demodulator (DEMOD;
• 23) capable of extracting said encoded data signal (NRZ) using said retrieved clock signal (CLKr).