| 摘要 |
A battery voltage detector detects a voltage of a battery, a battery alarm voltage detector detects whether the voltage of the battery has dropped to a battery alarm voltage, a near-battery alarm voltage detector detects whether the voltage of the battery has dropped to a near-battery alarm voltage, and a display brightness control unit decreases the brightness of a display unit if the near-battery alarm voltage detector detects that the voltage of the battery has dropped to a near-battery alarm voltage. |
