A peak location calculation device includes a peak value detection block that detects a plurality of candidates for a peak value of intensity of laser light received by an imaging unit consisting of an imaging element formed of a plurality of pixels, and a peak location calculation block that calculates an approximation function that approximates an intensity distribution of the laser light using the plurality of candidates for peak values detected by the peak value detection block. The peak location calculation block calculates the approximation function that minimizes an error between intensity values of the plurality of candidates for the peak value and values of the approximation function.

A system includes a multiplexed optical identifier and a reader for the optical identifier. The multiplexed optical identifier includes an optical substrate, and a plurality of volume holograms in the optical substrate. The reader includes an illumination source and a camera. The illumination source is configured to direct light into the optical identifier to produce an image of a corresponding one of the volume holograms at the camera, and the camera is configured to capture the image, which is stored in a digital format by the system. The multiplexed optical identifier contains more than one code page, wherein each of the code pages is used for a different purpose.

A system includes a multiplexed optical identifier and a reader for the optical identifier. The multiplexed optical identifier includes an optical substrate, and a plurality of volume holograms in the optical substrate. The reader includes an illumination source and a camera. The illumination source is configured to direct light into the optical identifier to produce an image of a corresponding one of the volume holograms at the camera, and the camera is configured to capture the image, which is stored in a digital format by the system. The multiplexed optical identifier contains more than one code page, wherein each of the code pages is used for a different purpose.

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.

A system includes a plurality of optical identifiers and a reader for the optical identifiers. Each optical identifier has an optical substrate and a volume hologram (e.g., with unique data, such as a code page) in the optical substrate. The reader for the optical identifiers includes an illumination source (e.g., a laser), and a camera. The illumination source is configured to direct light into a selected one of the optical identifiers that has been placed into the reader to produce an image of the associated volume holograms at the camera. The camera is configured to capture the image. The captured image may be stored in a digital format by the system.

Various devices and systems may benefit from enhanced reading of optical media. For example, certain computer systems may benefit from array reading of optical media. An apparatus may include, for example, an array of optical sensors. The array of optical sensors may be configured to read a plurality of parallel linear strips of data from an optical medium.

Various devices and systems may benefit from enhanced reading of optical media. For example, certain computer systems may benefit from array reading of optical media. An apparatus may include, for example, an array of optical sensors. The array of optical sensors may be configured to read a plurality of parallel linear strips of data from an optical medium.

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.