Abstract: A write-once read-many (WORM) optical disk recorder automatically calibrates its laser to emit a laser beam of a desired power level. While writing data to the WORM disk, a laser test signal is written to a laser checking area termed Automatic Laser Power Correction (ALPC) field. If the emitted laser test signal has a power level outside an acceptable power level window, then inappropriate laser power is indicated. Then, in an error recovery procedure (ERP) the laser power is calibrated in the data sector to be written to using short spaced-apart laser test signals. After successful calibration, data are written to the sector. The test signals appear as burst errors that can be corrected by a suitable error correction code. If such calibration is not successful then a write calibrate sector, WCS, is created and used for an extensive automatic calibration. In the WCS both laser power level is calibrated. The calibration result information is written to WCS for later use.

Abstract: A media library system has a plurality of independently-operated library arrays disposed in a side-by-side relationship along a first direction. Each of the library arrays has a media drive and a plurality of media storage receptacles arranged in a second direction that is transverse to the first direction. A separate media transport apparatus in each of the library arrays has a moveable media holder for moving media along the second direction between the storage receptacles in the library arrays and the media drives, respectively, in the independently-operated library arrays. A media exchanging and input common apparatus has a media carrier disposed for movement adjacent a common end of all of the independently-operated library arrays along the first direction. The media carrier has a media-transfer stop location at each of the library arrays at the common end of each of the library arrays.

Abstract: An optical device has an optical array detector with an array of optical receptors (each receptor is an individual photo detector) that has a greater cross-sectional extent than an impinging light beam. The receptors have respective light receiving areas smaller than the a cross-sectional area of the impinging light beam. A ring lens passes a received light beam to the receptor array. A ring lens refracts a defocused and off-track impinging light beam whereby the optical refractive properties of the ring lens change the cross-sectional form of the received light beam in accordance with status of the light beam. Refraction of the received light beam in the ring lens distorts the beam cross-sectional shape for indicating focus and location errors. Provisions are made for automatic calibration of the impinging beam to a current position of the array detector physical position by the optical device. Optical detection and re-calibration is effected by a digital signal processor.