Abstract: A compact optical scanner includes a base unit and a scan unit. The base unit includes an optical source such as a laser and an optical path directing a beam emitted by the laser to a scan mirror which is located in and supported by the scan unit. As the scan mirror rotates, the optical beam is reflected back to the base unit from which it is emitted as a beam scanning to and fro in a scan plane. The scan unit is supported by reference to the base unit such that the oscillation axis of the scan mirror is substantially and preferably parallel to the scan plane.

Abstract: A method of solder leveling in printed circuit boards or other circuitized substrates. Flux is first applied to the surface of the substrate to be soldered. Molten solder is then applied to the fluxed surface after which the soldered substrate is cooled to a temperature below 300.degree. F. Molten solder is then again applied to the previously soldered surface of the substrate. This last step results in leveling the solder first applied to the substrate, including removal of any solder balls which had been formed over recessed pins and flush filling of passage holes formed in the substrate. The method can be performed without regard to the surface condition of the substrate, the composition of flux and solder, whether the substrate is of the thin film type or of the thick film type, nor whether dip soldering or wave soldering techniques are used. The invention also incompasses the end product resulting from use of the method.

Abstract: A single-chip microcomputer device contains on-chip program storage in a read-only memory (ROM), and this program may be corrected or updated by patching. The ROM addresses are applied to an off-chip memory device containing one bit for each potential ROM address, and each bit is set to mark the beginning address of code to be patched; an interrupt is signalled when one of these set bits is accessed by an address occurring during operation of the microcomputer. The interrupt causes the processor to branch to an off-chip program memory to insert the patch code. The patch ends in a branch back to the on-chip ROM.

Abstract: A method and apparatus for detecting defects in apertures plates such as masks. The plate is illuminated by a collimated light beam and defects or irregularities are signalled by a bright spot of light. A modified microfilm reader or the like can be used to magnify and project an image of that portion of the plate associated with the bright spot of light.