Abstract: An apparatus includes a digital-to-analog converter operable to produce an analog output signal in response to a digital input signal, a final word clock signal CLK signal, and a final voltage reference signal; and a noise compensation circuit operable to receive an initial word clock signal and an initial voltage reference signal and to produce the final word clock signal and the final voltage reference signal such that errors in the analog output signal due to at least one of timing noise on the initial word clock signal and amplitude noise on the initial voltage reference signal are reduced.

Abstract: A system for the on-the-fly control of jitter during optical disc mastering/recording includes a record disc (24) having a recording surface (26) thereon of the type in which a pit can be read directly after it is written. A write-laser (32) directs its write-beam (34) though an acousto-optic modulator (36) onto the recording surface (26) of the rotating record disc (24). A digital processor (42) accepts digital input values and outputs a signal to the acousto-optic modulator (36) that effectively gates the write-beam (34) on and off. A read-laser (46) is positioned downtrack from the write-laser (32) and reads the pits (16) immediately or shortly after being written by the write-laser (32). The output of the read-laser (46) is fed into a jitter detector (48) that senses the start and stop positions of a sequence of pits (16) and effects an analysis to arrive at a jitter value.

Abstract: A method for authenticating digital storage devices, including compact discs, CD-Roms, DVDs and floppy discs, is provided. A predetermined "fingerprint" code is embedded in one or more of the parity bytes which are always appended to the end of data frames for the purpose of detecting and correcting errors in the data frames as they are read from the digital storage devices by playback devices, such as CD players, computers, and DVD players. The "fingerprint" code is embedded during the mastering process of the originally-produced, authentic storage device by a "fingerprint" encoder implemented by either hardware or software. The "fingerprint" is not transferred to target storage devices when the original storage device is copied because standard duplicating equipment do not have the "fingerprint" encoder which will be used by mastering equipment.

Abstract: Bonding of a plurality optical recording substrates in multi-layered optical recording mediums are facilitated by using ultraviolet lasers in a line-by-line manner such as telecentric scanning, raster scanning, circular scanning, or the like.

Abstract: A method and apparatus for creating an optical disk mother or stamper wherein the number of processing steps is greatly reduced from the prior art methods. In particular, the present invention involves directly forming a mother or stamper by direct laser ablation of a conductive metal substrate. More specifically, a stream of coded digital information (for example, representing the content of an encyclopedia in the case of CD ROM or a classical music collection in the case of CD audio) is converted into a corresponding plurality of pits and lands in the conductive metal substrate by electronically switching the beam of a first laser on and off via an electro or acusto-optic modulator (EOM/AOM) in response to the digital information. As a result, selective portions of the conductive substrate are either ablated (in the case where the laser is on) thereby directly creating the pits, or the substrate is left unaltered (in the case where the laser is off) thereby creating lands.

Abstract: A super high resolution rotary optical encoder having as its disk an optical disk, i.e., a disk employing the optical principle of non-contact readout based on diffraction theory. The encoder is adapted to be coupled to a device of which it is desired to measure the rotational motion thereof. The encoder includes an optical disk having, at a fixed radial distance, at least one track of pits and lands; a coupler for coupling the optical disk to the device such that rotary motion of the device results in a corresponding rotary motion of the optical disk; and an optical disk pick-up for generating an output in response to the pits and lands indicative of the rotary motion of the device.

Abstract: An optical disc player adapted to read an optical disc having a plurality of pits and lands representative of information stored on the optical disc; the optical disc being at least in part unmetallized. The player includes a semiconductor laser for generating a variable power laser beam, the power of the beam being controlled by a control signal applied to a control terminal of a semiconductor laser driver. A focusing servo is provided for focusing the beam on the optical disc such that a portion of the beam is reflected back from the optical disc indicative of the pits or lands. The portion of the beam reflected back from the optical disc being substantially less from unmetallized portions of the disc than from metallized portions of the disc. The focusing servo has a focal point constrained to lock on a pit plane of the optical disc.

Abstract: A method and apparatus for creating an optical disk mother or stamper wherein the number of processing steps is greatly reduced from the prior art methods. In particular, the present invention involves directly forming a mother or stamper by direct laser ablation of a conductive metal substrate. More specifically, a stream of coded digital information (for example, representing the content of an encyclopedia in the case of CD ROM or a classical music collection in the case of CD audio) is converted into a corresponding plurality of pits and lands in the conductive metal substrate by electronically switching the beam of a first laser on and off via an electro or acusto-optic modulator (EOM/AOM) in response to the digital information. As a result, selective portions of the conductive substrate are either ablated (in the case where the laser is on) thereby directly creating the pits, or the substrate is left unaltered (in the case where the laser is off) thereby creating lands.