Abstract: An apparatus and method for printing on plain paper, utilizing a solid-state write head to electrostatically release a pattern of dry toner particles from an informationless toner carrier. The pattern of released toner particles is accelerated across an air gap by an electrical field to impact on the paper.

Abstract: The invention defines a technique for assemblying all the parts of an electronic unit, for example a hand held calculator, directly on a plastic chassis without using individual printed circuit boards for various circuits of the calculator. Such parts of the calculator as the calculator chip, the display and the keyboard are all mounted on or formed on the plastic chassis in such a manner that only a cover has to be put over the plastic chassis to complete the calculator.

Abstract: Method and apparatus for testing and setting the field strength of permanent magnets in a magnetic bubble domain chip module, wherein the final molded module is formed to contain a pair of longitudinal slots which run through the module on opposite sides thereof. The module is inserted, via said slots, onto conducting members of a magnetic bubble module testing apparatus. The conducting members effectively provide one turn coils on each side of the module. Current is induced in these coils in such a way as to either add to or subtract from the bias field provided for the magnetic bubble domain chip by the permanent magnets of the module. The module is tested to determine the upper and lower operating levels of the bias field for effective operation of the chip, and the device is remagnetized to set the bias field of the module in the center, or optimal point, of the bias margin.