Abstract: A method for adjusting the timing for sampling a reflected write signal is disclosed. The method comprises determining a reference timing event, and sampling the reflected write signal at first and second sampling times to produce first and second sampled signals, the first sampling time occurring after a first variable time delay following the reference timing event and the second sampling time occurring after a first fixed time delay following the first sampling time. The method further comprises comparing the magnitudes of the first and second sampled signals, and adjusting the first variable time delay in response to the comparison of the magnitudes of the first and second sampled signals so that the magnitudes of the first and second sampled signals are substantially equal.

Abstract: An apparatus for use in an optical system in which information is read from a recorded wobbled groove of an optical medium by detecting first and second portions of a return beam in first and second detectors producing detected signals, respectively, the apparatus comprising:gain control circuit means coupled to the first and second detectors, respectively, and receiving the first and second detected signals therefrom;the gain control circuit means being responsive to the detected signals for producing a summation signal which is a function of the sum of the two detected signals;a first signal difference circuit coupled to the first and second detected signals for providing a difference signal; anda second signal difference circuit responsive to the difference signal and the summation signal for producing a wobbled groove information signal.

Abstract: A level detector for detecting a voltage level of a signal, is disclosed. The level detector includes a signal comparator having a first input for receiving the signal; a first switch responsive to an output of the signal comparator to connect a first current source to an output of the detector. The first current source connected between a first voltage reference and the first switch, the detector output feeding back to a second input of the signal comparator, such that the first current source supplies current to the detector output until a voltage at the detector output is greater than the voltage level of the signal.

Abstract: An optical recording system and method which provide verification of recorded data, while the data is being written onto an optical recording medium, by detecting the rate of change of a reflected write pulse. The system includes an optical source for supplying a intensity-modulated incident write signal, having at least one write pulse, to an optical recording medium. The write signal records a logic level of the data on the medium as a mark having a distinct reflectivity. An optical detector detects a reflection of the incident write signal from the medium to provide a reflected write signal which includes a reflected write pulse corresponding to the incident write pulse. The reflected write pulse has a rate of change resulting from a change in reflectivity of the optical medium as the mark is formed thereon.