an interface device for an optical recording and / or reproducing apparatus for recording and playback of an optical disc , wherein the configuration of an interface circuit between a pickup that reads and writes information from / on the optical disc and a radio frequency integrated circuit for signal processing is simplified . to this end , the interface device includes a pickup , an integrated circuit , and a multiplexer . the pickup drives a plurality of laser diodes generating laser signals to record and / or reproduce information on a plurality of discs , respectively , and receives the laser signals reflected from the discs and output photodiode signals corresponding respectively to the received laser signals . the integrated circuit controls outputs of the laser diodes , and processes the pd signals from the pickup . the multiplexer is disposed in the pickup , and selects a pd signal corresponding to a particular one of the discs from among the pd signals from the pickup and interface the selected particular pd signal to the integrated circuit .