摘要:
An optical data storage system comprises a multiple data surface medium and optical head. The medium comprises a plurality of substrates separated by a light transmissive medium. Data surfaces are located on the substrate surfaces which lie adjacent a light transmissive medium. The data surfaces are substantially light transmissive. The optical head includes an aberration compensator to allow the head to focus onto the different data surfaces and a filter to screen out unwanted reflected light.
摘要:
A laser based inspection tool (LIT) for inspecting planar surfaces is described. In a preferred embodiment the LIT can simultaneously inspect both planar surfaces of disks for use in disk drives. In an embodiment of the invention, light reflected from the surface at an angle slightly offset from perpendicular is routed through a telecentric lens to a detector which converts the intensity of the reflected beam into an analog signal. The analog signal is sampled and digitized to generate pixel data. A data acquisition system sequentially stores the pixel data in a buffer. A median filter and derivative analysis can be applied to the pixel data to detect deviations indicating defects. An optional calibration system periodically reflects the scanning beam back to a detector to form a reference signal for use in absolute reflectivity measurements.
摘要:
A laser based inspection tool (LIT) for inspecting planar surfaces is described. In a preferred embodiment the LIT can simultaneously inspect both planar surfaces of disks for use in disk drives. The LIT uses a mechanical lifter which moves the disk through the laser scan lines (i.e. perpendicular to the scan lines) to allow the entire surface on each side of the disk to be scanned. The light reflected from the surface is routed to a detector which converts the intensity of the reflected beam into an analog signal. The analog signal is sampled and digitized to generate pixel data. A data acquisition system sequentially stores the pixel data in a buffer. The edges of the planar surface in the pixel data are determined for each scan line while data acquisition is in progress. A mask is applied to direct the defect detection only to meaningful areas of the disk while data acquisition is in progress. A median filter and derivative analysis can be applied to the pixel data to detect deviations indicating defects.
摘要:
A laser based inspection tool (LIT) for inspecting planar surfaces is described. In a preferred embodiment the LIT can simultaneously inspect both planar surfaces of disks for use in disk drives. The LIT uses a mechanical lifter which moves the disk through the laser scan lines (i.e. perpendicular to the scan lines) to allow the entire surface on each side of the disk to be scanned. The light reflected from the surface is routed to a detector which converts the intensity of the reflected beam into an analog signal. The analog signal is sampled and digitized to generate pixel data. A data acquisition system sequentially stores the pixel data in a buffer. The edges of the planar surface in the pixel data are determined for each scan line while data acquisition is in progress. A mask is applied to direct the defect detection only to meaningful areas of the disk while data acquisition is in progress. A median filter and derivative analysis can be applied to the pixel data to detect deviations indicating defects. An optional calibration mirror is taught which is positioned to reflect substantially all of the incident beam during a segment of the scan line as the reflected calibration beam which is converted to an analog signal, sampled and digitized similarly to the reflected beam from the surface being inspected. By comparing the intensity of the calibration beam to the reflected beam the reflectivity of the surface can be measured.
摘要:
A multiple data layer optical disk drive system has fixed aberration correction and uses a disk with maximum interlayer spacing for reduced interlayer crosstalk. In one embodiment the multiple data layer disk has a substrate with a thickness that is reduced by approximately one-half the thickness of the spacer layer that separates the first and last data layers. The disk is designed to operate with a lens that has spherical aberration correction to compensate for the thickness of a conventional single data layer disk. This allows the disk drive to handle multiple data layer disks as well as to be backward compatible and thus handle conventional single data layer disks. The thickness of the substrate material plus one-half the thickness of the spacer layer material (which may have a different index of refraction than the substrate material) is equivalent, for purposes of spherical aberration correction, to the thickness of the substrate material used in the conventional single data layer disk. The focused spot with minimum spherical aberration is thus located at the middle of the spacer layer rather than on the first data layer. The spacer layer thickness is selected so that when the focused spot is located on either the first or last data layer there is some deliberately designed spherical aberration, although an amount that is acceptable. As a result the thickness of the spacer layer can be significantly increased to thereby reduce interlayer crosstalk. In another embodiment that substrate thickness and spacer layer thickness are selected and then the lens is corrected for spherical aberration corresponding to the thickness of substrate material plus one-half the thickness of spacer layer material.
摘要:
An optical data storage system comprises a multiple data surface medium and optical head, The medium comprises a plurality of substrates separated by a light transmissive medium. Data surfaces are located on the substrate surfaces which lie adjacent a light transmissive medium. The data surfaces are substantially light transmissive. The optical head includes an aberration compensator to allow the head to focus onto the different data surfaces and a filter to screen out unwanted reflected light.
摘要:
An optical data storage system comprises a multiple data surface medium and optical head. The medium comprises a plurality of substrates separated by a light transmissive medium. Data surfaces are located on the substrate surfaces which lie adjacent a light transmissive medium. The data surfaces are substantially light transmissive. The optical head includes an aberration compensator to allow the head to focus onto the different data surfaces and a filter to screen out unwanted reflected light.
摘要:
An optical data storage system comprises a multiple data surface medium and an optical head. The medium comprises a plurality of substrates, each supporting a data surface that contains optical media for the recording of data. The data surfaces are spaced apart so that each data surface can be accessed by focused laser light from the optical head. The type of optical media on each of the data surfaces may be ROM, write-once read-many (WORM), magneto-optic or phase change. At least one of the data surfaces includes recorded information located in a track header that identifies the type of optical media contained in the data surfaces.
摘要:
An optical data storage system comprises a multiple data surface medium and optical head. The medium comprises a plurality of substrates separated by a light transmissive medium. Data surfaces are located on the substrate surfaces which lie adjacent a light transmissive medium. The data surfaces are substantially light transmissive. The optical head includes an aberration compensator to allow the head to focus onto the different data surfaces and a filter to screen out unwanted reflected light.
摘要:
An optical data storage system comprises a multiple data surface medium and optical head. The medium comprises a plurality of substrates separated by a light transmissive medium. Data surfaces are located on the substrate surfaces which lie adjacent a light transmissive medium. The data surfaces are substantially light transmissive. The optical head includes an aberration compensator to allow the head to focus onto the different data surfaces and a filter to screen out unwanted reflected light.