Patent ID: 8120475

Claim:
A security-feature-equipped on-vehicle device comprising: a main body section including a front side; a front panel detachably attached to the front side of the main body section, the front panel including a display section; vibration detection means for detecting vibration; alarm sound output means for outputting a predetermined alarm sound from a speaker; and control means for placing the device in a sleep mode when the front panel is detached from the main body section, controlling the device to go from the sleep mode to a warning mode when vibration is detected for a first time by the vibration detection means, causing the alarm sound output means to output the alarm sound at a predetermined first volume level when the device is in the warning mode, shifting the device from the warning mode to an alarm mode when vibration is detected for a second time within a predetermined time period, causing the alarm sound output means to output the alarm sound at a predetermined second volume level higher than the first volume level when the device is in the alarm mode, returning the device to the sleep mode thereby stopping the alarm sound output means outputting the alarm sound, and placing the device in a security reservation mode when a number of times the device shifts to the alarm mode exceeds a predetermined threshold value, wherein the control means stops communication with the vibration detection means when the device is in the security reservation mode.