Abstract: Circuits, architectures, systems, methods, software, and algorithms for detecting a modulation transition (e.g., a change from a written portion containing RF-modulated data to an unwritten portion containing only a wobble signal modulation) on an optical storage medium. The method generally includes steps of focusing a first spot of light onto an optical storage medium, wherein the first spot is substantially centered on a first track of the optical storage medium, focusing a satellite spot of light onto an optical storage medium, wherein the satellite spot at least partially overlaps a track adjacent to the first track, generating a satellite signal from light reflected from the optical storage medium from the satellite spot, and detecting the modulation transition by detecting a change in a level of the satellite signal.

Abstract: A recording and reproducing system is arranged to record converted two-channel audio signals obtained by using all four-channel stereophonic audio signals and audio signals of two specific channels included in the four-channel stereophonic audio signals on a recording medium as four-channel recording audio signals and, at the time of reproduction, to be capable of restoring the four-channel recording audio signals to the four-channel stereophonic audio signals and also to permit either the four-channel stereophonic audio signals or the converted two-channel audio signals to be selectively outputted.

Abstract: In an optical data recording/reproducing apparatus for performing write and read operations of data by irradiating laser light onto an optical data recording medium, in order to reduce noise of a semiconductor laser, an HF oscillator is provided to superpose an HF current on a drive current to be applied to the semiconductor laser. The HF oscillator is housed in a conductive shield case together with the semiconductor laser. An LC low-pass filter is also provided in a signal line connecting the components inside and outside the shield case to prevent undesired radiation of the HF current. A write drive line and a read drive line of the semiconductor laser are separated in the shield case, and the write drive line is disconnected from the HF oscillator in at least a read mode.

Abstract: The present invention provides a multi-channel stereo reproducing apparatus which can reproduce a recording medium such as an audio disc or the like in which in order that users can enjoy screen musics or the like reproduced at, for example, a concert hall and a movie theater.

Abstract: A video disc player includes a pick-up cartridge in which the stylus is supported by a stylus holder that is mechanically resonant at a frequency within an audio frequency range. A pick-up converter coupled to the stylus provides a broad audio video output signal that is undesirably modulated due to the stylus holder mechanical resonance. The audio signal is demodulated to baseband and linearly combined with the un-demodulated broadband signal to provide a resultant audio output signal in which audio frequency noise components, due to the mechanical resonance of the resulus holder, are attenuated.