Abstract: A method of manufacturing an optical disc master includes preparing the surface of a glass master plate (2) with an adhesion promoter 4. A photoresist layer (6) is coated on the adhesion promoter (4). This photoresist layer (6) is subjected to a first exposure of a modulated laser beam (8) to produce an exposed photoresist layer (10) corresponding to the modulation information of the laser beam (8). A transparent sheet (16) is placed on the photoresist layer (6). This sheet (16) contains a distinguishing mark to be located in the optical disc. White light (18) from a second light source is passed through the sheet (16) onto the photoresist layer (6) to expose the upper surface of this layer (6). The exposed part of this upper surface provides a pattern (22) corresponding to the mark on the sheet (16). The exposed master plate (2) is then developed to form the pits (12) and a reproduction (24) of the pattern (22).

Abstract: An automated, optical-mechanical apparatus includes a laser, a series of lenses for focusing a measuring beam generated by the laser to a precise focal distance and dispersion angle, a lead screw for linearly translating the beam and a spindle for aligning the optical discs to be scanned and counted. The beam is focused to the edge of the stacked discs and propagates through the gaps between adjacent discs to an optical detectors where the beam is transformed to an electronic waveform, which is interpreted by a digital counting network. Counting accuracy is not dependent upon precise control of manufacturing variations in the thickness and weight of the discs.

Abstract: A method and apparatus for providing a graphical image on an optical recording disc are described. The method includes the steps of storing a digital image in a first coordinate system as a first array of bits in a digital memory, transforming the digital image from the first coordinate system to an angular coordinate system such as polar coordinates to generate a second array of bits, and then using the second array of bits to modulate a writing beam in an optical disc mastering process to write the transformed digital image onto an optical recording disc. The digital image can be obtained alternately from an optical scanner or conventional image preparation software. The method can also include the step of editing an initial array of bits to form the first array of bits.