An autonomous search light system for being mounted to an aircraft includes a search light for emitting an adjustable light output; an RF receiver with at least two RF antennas for receiving RF signals emitted by an RF transmitter; and a controller for determining a position of the RF transmitter in relation to the search light from the received RF signals and for controlling the search light based on the determined position of the RF transmitter.

In an optical disc apparatus for reproducing information recorded on a track of an optical disc, an optical head irradiates a light beam onto the track, detects a reflected light reflected by the track, and generates a reproduction signal based on the reflected light. A decoder circuit decodes the reproduction signal, and generates a decoded signal including information recorded on the track. A correlation detector circuit calculates a cross-correlation value between the reproduction signal and the decoded signal. A servo circuit detects a deviation amount of an irradiation position of the light beam onto the track, from the reproduction signal, and controls the irradiation position of the optical head based on the cross-correlation value and the deviation amount.

A disc recorder and player apparatus includes a plurality of recorder and player subsystems, a disc motor, and a controller. Each of the recorder and player subsystems includes a pickup and a traverse motor. When one of the recorder and player subsystems writes or reads data on or from a first track on the disc recording medium, the controller prohibits the other of the recorder and player subsystems from writing and reading data on and from a second track on the disc recording medium as well as moving the pickup to the second track, the second track being at a position different from a position of the first track, and the second track being to be accessed at a rotational speed different from a rotational speed for the first track.

The first, third, fourth, and seventh photosensors are disposed on one side with respect to the centerline, and the second, fifth, sixth, and eighth photosensors are disposed on another side with respect to the centerline. The first and seventh photosensors are positioned between the third and fourth photosensors in the direction parallel to the centerline. The second and eighth photosensors are positioned between the fifth and sixth photosensors in the direction parallel to the centerline. The first photosensor receives overlapped light of the 0th-order light with the +1st-order diffracted light, the second photosensor receives overlapped light of the 0th-order light with the −1st-order diffracted light, each of the third to sixth photosensors receives the 0th-order light, and does not receive the +1st-order diffracted light and the −1st-order diffracted light, and each of the seventh and eighth photosensors receives at least the 0th-order light.

A radial servo control device for a super-resolution optical disc includes an excitation light source, a servo light source, an integrated optical path, focusing units, a servo light detecting unit and a drive control unit; the drive control unit presets N detection error reference values with respect to each guide layer trench irradiated by servo light, and controls corresponding positions of the focusing units in N data tracks below each guide layer trench according to a comparison result between a detection result of servo reflected light and the detection error reference values. The device is applicable to a variety of super-resolution optical discs on the basis of stimulated radiation loss microscopy technology, a two-photon absorption technology, and the like, and achieves accurate radial servo control of super-resolution data tracks (<100 nm) without reducing the wavelength of servo light and the width of guide layer trenches.

A radial servo control device for a super-resolution optical disc includes an excitation light source, a servo light source, an integrated optical path, focusing units, a servo light detecting unit and a drive control unit; the drive control unit presets N detection error reference values with respect to each guide layer trench irradiated by servo light, and controls corresponding positions of the focusing units in N data tracks below each guide layer trench according to a comparison result between a detection result of servo reflected light and the detection error reference values. The device is applicable to a variety of super-resolution optical discs on the basis of stimulated radiation loss microscopy technology, a two-photon absorption technology, and the like, and achieves accurate radial servo control of super-resolution data tracks (<100 nm) without reducing the wavelength of servo light and the width of guide layer trenches.

An autonomous search light system for being mounted to an aircraft includes a search light for emitting an adjustable light output; an RF receiver with at least two RF antennas for receiving RF signals emitted by an RF transmitter; and a controller for determining a position of the RF transmitter in relation to the search light from the received RF signals and for controlling the search light based on the determined position of the RF transmitter.

A cross section of a luminous flux of returning light from a disc is split into a plurality of regions, and an operation is performed so that a weighting of a light amount of a region which has favorable symmetry in a radial direction and is formed on a circumference of an ellipse among the split regions is increased. Further, a lens shift detection signal is formed, and a lens shift detection signal is canceled from a push-pull signal.

A cross section of a luminous flux of returning light from a disc is split into a plurality of regions, and an operation is performed so that a weighting of a light amount of a region which has favorable symmetry in a radial direction and is formed on a circumference of an ellipse among the split regions is increased. Further, a lens shift detection signal is formed, and a lens shift detection signal is canceled from a push-pull signal.

Digital optical tape archival storage systems and methods are disclosed. A digital optical tape recorder simultaneously writes data and two or more guide tracks onto an unformatted digital optical tape recording medium. A digital optical tape reader includes a camera and an image processor. The camera captures a two-dimensional image of the digital optical tape recording medium including the data and the two or more guide tracks. The image processor extracts the data from the two-dimensional image based, at least in part, on the guide tracks.