Method and apparatus for storage and retrieval with multilayer optical disks
AssigneeYeda Research and Development Co. Ltd.
InventorsErez Hasman, Asher A. Friesem
Life of this patent
Estimating the term…
Abstract
A multilayer optical disk system, which includes an optical disk unit having a number of connected optical disks. A number of light sources, such as diode lasers, are used to provide a number of light beams of different wavelengths. A wavelength multiplexer combines the light beams into a single beam which is then axially dispersed so that light of different wavelengths are simultaneously focuses onto the different optical disks. A wavelength demultiplexer splits light reflected from the optical disks according to wavelength to produce separate beams which are then separately detected.
Claims35
A multilayer optical disk system, comprising:
- (a) an optical disk unit including a plurality of connected optical disks;
- (b) a plurality of light sources for providing a plurality of light beams of different wavelengths;
- (c) a wavelength multiplexer for combining said plurality of light beams into a single beam;
- (d) axially dispersing optics for simultaneously focusing said single beam onto two or more of said optical disks;
- (e) a wavelength demultiplexer for splitting light reflected from said two or more of said optical disks according to wavelength to produce two or more separate beams;
- and
- (f) a plurality of detectors, each of said detectors detecting one of said two or more separate beams.
A two-layer optical disk system, comprising:
- (a) an optical disk unit including a pair of connected optical disks, at least one of said optical disks being partially transparent;
- (b) a single light source for providing a light beam;
- (c) an axially dispersing bifocal focusing element for simultaneously focusing said light beam onto said pair of optical disks;
- (d) a beam-splitter for splitting light reflected from said pair of optical disks to produce two separate beams;
- and
- (e) a pair of detectors, each of said detectors detecting one of said two separate beams.
A method for simultaneously reading a plurality of optical disks of a multilayer optical disk system, comprising the steps of:
- (a) providing a plurality of light beams of different wavelengths;
- (b) combining said plurality of light beams into a single beam;
- (c) axially dispersing said single beam so as to simultaneously focus said single beam onto two or more optical disks of an optical disk unit including a plurality of connected optical disks;
- (d) splitting light reflected from said two or more of said optical disks according to wavelength to produce two or more separate beams;
- and
- (e) separately detecting said two or more separate beams.
A method for simultaneously reading both optical disks of a two-layer optical disk system, comprising the steps of:
- (a) providing a single light beam;
- (b) axially dispersing, using a bifocal focusing element, said single beam so as to simultaneously focus said light beam onto the two optical disks of the two-layer optical disk system, at least one of said disks being partially transparent;
- (d) splitting light reflected from said two of said optical disks to produce two separate beams;
- and
- (e) separately detecting said two separate beams.
Dependencies are inferred from the claim text.