摘要:
A method for detecting and optimizing the quality of a mark made by a laser on a recording medium, comprising (a) recording a test mark at a selected level of laser power and a selected speed of movement of the recording medium, (b) measuring at least one dimension of the test mark, (c) comparing the at least one dimension of the test mark to a stored reference value for at least one reference dimension, and (d) determining whether the at least one dimension of the test mark is comparable to the at least one dimension of the stored reference value.
摘要:
Various systems, methods, and programs embodied on a computer-readable medium are provided for calibrating a laser power in an optical disc drive. In one embodiment, a range of reflectivity of an optical disc in the optical disc drive is established. A calibration pattern of marked segments is written to the optical disc and the reflectivity of the marked segments is measured. An average reflectivity is generated for each one of a plurality of laser power settings within the range of reflectivity, thereby obtaining a curve that depicts the average reflectivity with respect to the laser power settings. The laser power setting at a knee of the curve is identified and a slope of the curve at a position on the curve where the average reflectivity decreases as the laser power settings increase is determined. The laser power setting is calculated that results in a predefined darkness based upon the laser power setting at the knee and based upon the slope.
摘要:
This invention relates to a method of determining the location of a plurality of laser spots, comprising: determining a first distance of a first laser spot; determining a second distance of the first laser spot; determining a first distance of a second laser spot; determining a second distance of the second laser spot; and adjusting, if necessary, the locations of the first and second laser.
摘要:
The present invention relates to the attachment of latency-intolerant devices, such as CD-RW devices to a well supported high bandwidth interface on a host computer. A preferred high bandwidth interface is the Universal Serial Bus (USB) which is commonly installed in personal computers manufactured in the late 1990's. A need for both high pre-allocated bandwidth makes use of the Isochronous transfer mode desirable for communication with CD-RW and other devices requiring continuous data transmission. One of a range of data reliability mechanisms is preferably implemented on the connection to the USB to ensure accuracy in data transmission to the various devices connected to the USB.
摘要:
A system for attaching an adhesive backed write-protect ring to an optical disk with the center of the ring aligned to the center of the central hole in the disk. A write-protect assembly is formed from a multilayer material having an adhesive backed label layer and a backing layer. The write-protect assembly includes a removable innermost area that, when removed, forms a hole having a diameter that is the same diameter as the central hole of an optical disk. The innermost area is at least partially surrounded by a ring shaped alignment area that is also removable. Finally, the alignment area is surrounded by the write-protect ring. The central area of the assembly is punched out to form a hole and the backing material is removed from at least part of the write protect area, exposing the adhesive coated surface. The assembly and an optical disk are placed onto an alignment cylinder. The alignment area of the write-protect assembly ensures that the center of the write-protect ring is aligned to the center of the hole in the disk. Finally, the disk with write-protect ring and alignment area attached is removed from the alignment cylinder and the alignment area of the write-protect assembly is removed, leaving just the write-protect ring attached to the disk. The hub of the plastic insert tray of a CD jewel case may be used for an alignment cylinder. In an alternative embodiment of the invention, the write-protect assembly is placed onto the hub first, and the design of the assembly is such that the hub helps remove the central area and the hub helps removal of the backing over the write-protect ring.
摘要:
A digital line driver circuit with active pull-down, high transient pull-up current, and limited steady-state pull-up current. Steady-state pull-up current is provided through a pull-up resistor. Transient pull-up current is provided by a capacitively coupled active pull-up circuit.
摘要:
Various systems, methods, and programs embodied on a computer-readable medium are provided for calibrating a laser power in an optical disc drive. In one embodiment, a range of reflectivity of an optical disc in the optical disc drive is established. A calibration pattern of marked segments is written to the optical disc and the reflectivity of the marked segments is measured. An average reflectivity is generated for each one of a plurality of laser power settings within the range of reflectivity, thereby obtaining a curve that depicts the average reflectivity with respect to the laser power settings. The laser power setting at a knee of the curve is identified and a slope of the curve at a position on the curve where the average reflectivity decreases as the laser power settings increase is determined. The laser power setting is calculated that results in a predefined darkness based upon the laser power setting at the knee and based upon the slope.
摘要:
A system and method for determining when data stored in a data storage device is becoming unreliable. A list of trigger events is maintained, either on the media, or on a host processor, and the number of trigger events pertaining to data retrieval errors is also maintained either on the disc media or on the host processor. Based upon the trigger events and the running totals, the disc media is scanned for errors from time to time and the error detecting algorithm can change depending upon the respective trigger totals. The triggers are typically representative of events likely to cause errors to occur and can be tailored to different types of storage media
摘要:
Various systems, methods, and programs embodied on a computer-readable medium are provided for calibrating a laser power in an optical disc drive. In one embodiment, a plurality of marked segments of a calibration pattern are created on a label surface of an optical disc with a laser in the optical disc drive. The marked segments are created by the application of assorted quanta of radiant energy from the laser. The reflectivity of the marked segments is measured. Ultimately, the laser power of a laser in the optical disc drive is set for writing a label based upon the reflectivities measured for each of the marked segments for each quantum of radiant energy.
摘要:
A method and apparatus for write protection of rewritable compact disks and digital video disks. A Power Calibration Area is covered to prevent the drive laser from completing a calibration procedure. In one embodiment, the disk has an indented area formed around the central hole in the disk. A ring shaped plug is inserted into the indented area, with an extended surface that covers the calibration area. In an alternative embodiment, an adhesive label, ink, dye or paint is used. In still another alternative embodiment, the calibration area is mechanically abraded to provide permanent write protection. Finally, the laser in the drive may be used to darken, damage or destroy the calibration area or a transparent label over the calibration area, for permanent write protection.