Abstract: A signal light including a housing is recessed into a traffic surface and projects minimally upwardly from the surface and wherein a light processing assembly is provided to receive light from a light source, intensify the light and direct the light toward a light outlet in a generally linear manner, the arrangement for processing light being mounted to the housing. For this purpose, the light source is designed in such a way that it sends an essentially linearly directed light beam onto the light processing assembly. The light is collected in the light processing assembly in such a way that, when it exits, it is still linearly extending in at least one direction but it has a higher intensity. For this purpose, the light processing assembly includes a cylindrical-convex lens entry surface and a cylindrical concave mirror surface for receiving and directing light.

Abstract: Thermal ink jet apparatus includes an ink jet pen with a plurality of ink ejection nozzles. Associated with each nozzle is a first resistor and second resistor. A feed channel introduces a quantum of ink into thermal communication with each first resistor and second resistor. The quantum of ink requires a level of applied thermal energy of E.sub.min to be caused to be ejected from the associated nozzle. An X-Y matrix drive circuit selectively applies a half-select address current to a first resistor and a half-select address current to a second resistor, both resistors located at a common nozzle. Each half-select current is insufficient to cause a resistor to emit E.sub.min thermal energy, but both half-select currents cause the first and second resistors to couple at least E.sub.min of thermal energy to the co-located quantum of ink so as to enable an ejection thereof.

Abstract: The output voltage of a battery in a portable digital electronic instrument is compared with an internal voltage reference. When the battery voltage falls below the reference voltage, the true decimal point of the number being displayed is not illuminated and a plurality of the adjacent decimal points are illuminated.