Abstract: An illuminating unit (28) is presented for use in an internally illuminated sign device (1) for displaying a pattern indicative of certain fixed information within an indicia area. The illuminating unit (28) comprises a light boundary structure (33) for a light source (38) to be mounted thereon. The light boundary structure (33) has an indicia area carrying side (16) having said pattern indicative of the information to be displayed, and has an inner surface made of at least one highly reflective material to thereby increase the amount of light propagating from the light source (38) to said indicia area.

Abstract: An illuminating unit (28) is presented for use in an internally illuminated sign device (1) for displaying a pattern indicative of certain fixed information within an indicia area. The illuminating unit (28) comprises a light boundary structure (33) for a light source (38) to be mounted thereon.

Abstract: A voltage-adder circuit, which adds the charge stored on a capacitor during a switch off-time, to the voltage of the input battery/power-supply, to provide an output voltage greater than the input voltage. The circuit is especially well-suited for use as an LED driver, and may be also used as a voltage booster for low-voltage electronic circuitry, such as electronic watches; as a back-bias generator for use inside integrated circuits; and, as a gate-bias-voltage generator, for use with depletion-mode GaAsFETs, such as are used in the transmitters of cellular telephones. The circuit obtains high efficiency operation by the use of inductors to charge a storage capacitor. Switches may be added. The invention includes a novel self-operating switch.