Abstract: A Fresnel lens formed of an infrared transmitting material has a grooved surface. The grooves all extend to the same depth, and the distances between successive grooves vary across the lens. In a circular lens, the grooves are concentric, and the distances between grooves nearer the center are longer than the distances between the grooves nearer the circumference. A substantial portion of the grooves have an aspherical surface.

Abstract: A price quotation system for conveying quotations of interest to the financial community comprising a transmitter for receiving a plurality of said quotations and broadcasting serial data representing each of said quotations, a handheld, portable receiver for receiving the serially transmitted data, storage means in the handheld receiver for individually storing the serially received data representing each of the quotations, a display on the handheld receiver, and means on the handheld receiver coupled to the storage means and the display means for individually selecting the stored data representing any one of the quotations and displaying it as a selected quotation.