A digital camera is provided with, a voltage detection unit for a driving power supply, a temperature detection unit which detects an inner temperature and an outer temperature of the apparatus, a power supply detection unit which detects whether the power supply is an AC power supply or a DC power supply...http://www.google.com/patents/US7110037?utm_source=gb-gplus-sharePatent US7110037 - Automatic focus control based on voltage, temperature, and power supply
