Abstract: An electro-optic display comprising at least two separate layers of electro-optic material, with one of these layers being capable of displaying at least one optical state which cannot be displayed by the other layer. The display is driven by a single set of electrodes between which both layers are sandwiched, the two layers being controllable at least partially independently of one another. Another form of the invention uses three different types of particles within a single electrophoretic layer, with the three types of particles being arranged to shutter independently of one another.

Abstract: A collapsible frame assembly having a first supporting frame and a second supporting frame mounted onto the first supporting frame in such a manner as to be movable up and down with respect to the first supporting frame. The frame assembly having three or more lazy tong arrangements pivotally connected to the first and second supporting frames. The frame assembly also has moving mechanisms for extending and retracting the lazy tong arrangements between a retracted position and an extended position that form respectively a collapsed structure and an arch-like freestanding structure.

Abstract: A system for obtaining digitized samples of an analog signal at a selectable rate, R. The system includes: a timing generator for producing a train of sampling pulses at a predetermined sampling rate, f.sub.s ; an analog to digital converter for producing a digitized sample of the analog signal in response to each one of the sampling pulses; a processor; and, a selector, for passing each Nth one of the digitized samples produced by the analog to digital converter, where N=f.sub.s /R to the processor. The selector includes a decimator, responsive to a signal, N=f.sub.s /R, representative of the ratio of the sampling rate, f.sub.s, to the digitized signal obtaining rate, R, for producing pulses at the rate, R=f.sub.s /N; and, a register for storing each Nth one of the digitized samples produced by the analog to digital converter, each one of such digitized samples being stored in response to a corresponding one of the pulses produced by the decimator.

Abstract: A method of producing a control signal for a range gate in a pulse Doppler radar, the method encompassing the steps of periodically determining the range slip of a selected target and then changing the position of a range gate during each range sweep in accordance with the determined range slip.