A photo detector having an electrically conductive thin film and a light-receiving unit. The estimated position of the vehicle is then evaluated based on a distance between the estimated position and the center locus to yield a position candidate evaluation for displaying a current position mark on a displayed map. By generating the list of interests based on user interaction with the catalog, the list of interests may be generated based on factual data rather than user opinion. This different communication means has limited communication resources. The encoder provides timestamp information to the data packet stream generator and the data packet stream generator synchronizes annotation data from the annotation source with a video signal from the video source in response to the timestamp information.