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.
Type:
Grant
Filed:
July 29, 1994
Date of Patent:
February 27, 1996
Assignees:
Sony Corporation, Sony Music Entertainment
Abstract: A trapped energy piezoelectric resonator for oscillator and multiple resonator applications has a piezoelectric substrate with electrodes disposed on each of its major surfaces. These electrodes are further comprised of a plurality of electrically interconnected and acoustically coupled sub-electrodes. The resonant frequency of these resonators may be controlled by varying the separation and, therefore, the acoustic coupling between the sub-electrodes. This resonator may be used in the feedback loop of an oscillator circuit as the frequency determining element. It may also be used to provide a resonator on a substrate carrying resonators of significantly different frequency.