Abstract: A touch screen input device for improving the input of alphanumeric data in an area of limited space. The input device employs a multi-touch method of input which is intuitive to a first time user. The device maps a plurality of characters to each of its input keys and upon selection of a key subsequently re-labels the input keys with the characters displayed on the selected key. The device is intuitive to a first time user since the input keys are re-labeled in manner which corresponds to their relative position within the selected input key. In comparison to single stroke input devices this device reduces the number of keys required for data input. Alternatively a user could select a single character without employing the multi-touch method by selecting a pre-defined element of a particular input key.

Abstract: An alphanumeric, and graphics liquid crystal display having utility in portable devices used in communications, measurement, and data display systems generally, is disclosed in the environment of a wireless telephone handset. The display includes a transparent viewing screen having a reflective substrate adapted to display thereon transitory opaque symbols in response to data signals received during a telephone call or generated at a keypad of the handset when a call is placed. Positioned under the substrate, an illumination screen has selectable elements which are illuminated in response to control signals generated in correspondence with the data signals. Being in registry with portions of the substrate on which the symbols are displayed, the selected elements of the illumination screen provide backlighting for viewing the symbols under low ambient light levels without illuminating the entire viewing screen, thereby conserving power in an on-board battery.

Abstract: An alphanumeric, and graphics liquid crystal display having utility in portable devices used in communications, measurement, and data display systems generally, is disclosed in the environment of a wireless telephone handset. The display includes a transparent viewing screen having a reflective substrate adapted to display thereon transitory opaque symbols in response to data signals received during a telephone call or generated at a keypad of the handset when a call is placed. Positioned under the substrate, an illumination screen has selectable elements which are illuminated in response to control signals generated in correspondence with the data signals. Being in registry with portions of the substrate on which the symbols are displayed, the selected elements of the illumination screen provide backlighting for viewing the symbols under low ambient light levels without illuminating the entire viewing screen, thereby conserving power in an on-board battery.