A tilt servo control apparatus for an optical disk is provided, which is able to keep a high reproduction quality by correcting tilt errors with its construction simplified and compact. The tilt servo-control apparatus includes: an optical pickup for irradiating an optical beam onto an optical disk and detecting a reflected light from the optical disk; a tilt-correction unit for correcting, using a correction amount, a tilt error due to aberration caused by a tilt angle formed between an optical...

An optical information reproduction apparatus is provided that, even when spherical aberration has occurred because of a thickness error in a transmissive substrate of an optical disk, is capable of improving the information reading accuracy by correcting the spherical aberration. The spherical aberration of an optical system is corrected while changing the amount of correction in a state where an objective lens is retained at a position on a focus adjusting orbit where the amplitude level of a ...

An optical information reproducing device enables enhancement of information reading accuracy by correcting spherical aberration even if the spherical aberration occurs due to a thickness error in the transparent substrate of an optical disk. The correction amount of the spherical aberration is always changed such that the tracking servo gain in the tracking servo becomes maximum.

A solid-state imaging device includes a two-dimensional array of photosensor sections on a semiconductor substrate, and a vertical transfer section including two-layer vertical transfer electrodes. The photosensor sections store signal charges generated by photoelectric conversion. The vertical transfer section reads signal charges from the photosensor sections and vertically transfers the read signal charges. The two-layer vertical transfer electrodes have first transfer electrode layers and se...

A data reproduction method and apparatus reads the tracks of an optical disk by means of a read unit having a plurality of optical beams. The method includes a first reproduction step for simultaneously playing back a first plurality of tracks on a disk using the plurality of optical beams; a first jump step for jumping a greater number of tracks than the number of optical beams in a forward direction; a second reproduction step for simultaneously playing back a second plurality of tracks on the...

A drive apparatus including: a superposition device which superposes a superposition signal on a drive signal for driving a light beam emission device that emits a light beam and which outputs the drive signal on which the superposition signal is superposed to the light beam emission device, a reference clock signal generation device which generates a reference clock signal, a frequency change device which changes a frequency of the superposition signal based on a quality index for indicating a ...

An optical pickup apparatus comprises a semiconductor laser output controller for emitting laser beam, a photodetector for detecting the emitted laser beam, a sampling processor for performing a sampling process, a pulse current generator for generating erase current pulses, write current pulses, and read current pulses, and a controller for controlling the above components. The apparatus performs the sampling process and generates the current pulses according to a predetermined APC timing and c...

A coding apparatus for a moving object image input signal such as a television signal detects an uncovered background area appearing upon movement of a moving object in the moving object image input signal and encodes an image signal corresponding to the uncovered background area according to intraframe correlation instead of interframe correlation. The coding apparatus includes a noise reduction circuit for decreasing a noise reduction level for the signal corresponding to the uncovered backgro...

On subjecting a digital video signal representative of successive pictures to predictive coding by using correlation between two successive pictures, an estimated result is derived from the digital video signal to represent a degree of correlation between a current picture and a previous picture and is increased with a reduction of the degree. When the estimated result becomes greater than a predetermined threshold value as a result of a drastical change, such as a scene change, from the previou...

In a movement compensation predictive encoder, a vector detector (19) is supplied with a moving picture signal and produces a movement vector signal representative of at least one movement vector for each region of each frame. A picture analyzer (16) serves as a variation detector for detecting a variation in each region to produce a variation signal when the variation exceeds a predetermined threshold in one of the regions. The variation signal is used in giving a predetermined value, such as z...