A battery powered key entry device including a processor and a power conservation system.

摘要

In a self-contained battery powered key entry device, the keyboard (2) is driven from a microprocessor (1) and its output sensed by the microprocessor to generate drive signals for an infra-red transmitter (24). The sense lines (DBO-DB7) are monitored so that, on a key depression, the microprocessor is switched to an operating mode from its low-power standby mode. When all sensed signals have been processed and outputted, the microprocessor is returned to the low-power standby mode. A delay may be incorporated.