| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To realize the high efficiency and high S/N ratio of a switching power supply circuit. <P>SOLUTION: A CPU 11 operates a switching power supply 20 in a PWM fixed operation mode with a fixed pulse cycle by giving an instruction via a control signal, in operation modes requiring a high S/N such as a still image capture operation mode (shutter half-pressed, shutter fully pressed), a moving image recording operation mode (under recording), and a REC (recording) through operation mode with high sensitivity being set (non-recording). Further, the CPU 11 operates the switching power supply 20 in an automatic switching operation mode in which PWM control and PFM control are switched over according to an amount of load by giving an instruction via a control signal in operation modes requiring no high S/N such as a normal sensitivity REC through operation mode (non-recording), a PLAY (reproduction) mode, a menu operation mode, and a power supply trigger/off mode. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
