Patent attributes
An operator-specifying apparatus is combined with an on-board device such as a navigation device mounted on an automotive vehicle. An ultrasonic sensor device is mounted on a frame of a display panel of the navigation device. A hand of a person who is manipulating the navigation device, a driver or an assistant, is detected by the ultrasonic sensor device. If it is determined that the driver is manipulating (or about to manipulate) the navigation device when the vehicle is being driven, manipulation of the navigation device is prohibited to secure safety in driving. On the other hand, if it is found out the assistant is operating the navigation device, such prohibition is canceled to effectively use the navigation device.