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.

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.

In a multilayer optical disc having information layers conforming to a plurality of different optical disc standards, because the type of each information layer is not recorded in the other information layers, in read and write operations by a compatible optical disc device conforming to a plurality of optical disc standards, every time the information layer being accessed changes, it has been necessary to read the type of the information layer and select a method of generating a tracking error signal adapted to the type of information layer, so access has taken time. In order to solve the above problem, in the optical multilayer disc according to the present invention, having information layers conforming to a plurality of different optical disc standards, in an area in one of the information layers, information about the other information layers is recorded. The time required to access the other information layers can be reduced by using this information to select a tracking error signal generating method.

In a multilayer optical disc having information layers conforming to a plurality of different optical disc standards, because the type of each information layer is not recorded in the other information layers, in read and write operations by a compatible optical disc device conforming to a plurality of optical disc standards, every time the information layer being accessed changes, it has been necessary to read the type of the information layer and select a method of generating a tracking error signal adapted to the type of information layer, so access has taken time. In order to solve the above problem, in the optical multilayer disc according to the present invention, having information layers conforming to a plurality of different optical disc standards, in an area in one of the information layers, information about the other information layers is recorded. The time required to access the other information layers can be reduced by using this information to select a tracking error signal generating method.

An optical information recording apparatus and method thereof for recording information in a holographic medium. The apparatus includes a laser source which generates a reference beam and a signal beam to record the information in the holographic medium, a sensor which detects a vibrational amplitude over a time period applied to the optical information processing apparatus for recording the information, an operational circuit which calculates from the vibrational amplitude at least one statistical measure of the vibrational amplitude; and a processor programmed to control a recording mode such that the processor evaluates the calculated statistical measure to determine continuation of a recording operation to the holographic medium.

An optical information recording apparatus and method thereof for recording information in a holographic medium. The apparatus includes a laser source which generates a reference beam and a signal beam to record the information in the holographic medium, a sensor which detects a vibrational amplitude over a time period applied to the optical information processing apparatus for recording the information, an operational circuit which calculates from the vibrational amplitude at least one statistical measure of the vibrational amplitude; and a processor programmed to control a recording mode such that the processor evaluates the calculated statistical measure to determine continuation of a recording operation to the holographic medium.

Methods and apparatuses for detecting mode hopping in a laser diode or other optical energy source in heat-assisted magnetic recording. An output power of the laser diode or other optical energy source is measured and the output power is differentiated over time to determine a rate of change. If it is determined that the rate of change exceeds a threshold value, a fault signal is asserted indicating a potential mode hopping event.

A reproducing device (100) includes (i) an optical pickup (6) for irradiating, with reproduction light, an optical disk (1) which is a super-resolution medium, (ii) an RF signal processing circuit (9) for converting, into a reproduction signal, light which reflected off optical disk (1), (iii) an i-MLSE detecting section (141) for evaluating quality of the reproduction signal, and (iv) a spherical aberration correcting section (142) for correcting a spherical aberration by using a result of evaluation of the quality of the reproduction signal.

A reproducing device (100) includes (i) an optical pickup (6) for irradiating, with reproduction light, an optical disk (1) which is a super-resolution medium, (ii) an RF signal processing circuit (9) for converting, into a reproduction signal, light which reflected off optical disk (1), (iii) an i-MLSE detecting section (141) for evaluating quality of the reproduction signal, and (iv) a spherical aberration correcting section (142) for correcting a spherical aberration by using a result of evaluation of the quality of the reproduction signal.

A record playback apparatus of the present disclosure includes a plurality of optical pickups that records information on a recording medium or plays back information from the recording medium; a single transport mechanism that transports the plurality of optical pickups together; and a transport control circuit that drives the single transport mechanism so that, when the single transport mechanism is driven to transport the plurality of optical pickups to respective target positions on the recording medium, absolute value of a maximum value of transport errors of the plurality of optical pickups with respect to the respective target positions becomes substantially equal to absolute value of a minimum value of transport errors of the plurality of optical pickups with respect to the respective target positions.