Abstract: A car-mounted image recording apparatus comprises an imager operable to take a moving image of outside scene of a vehicle, an image quality controller operable to determine importance of present position of the vehicle, and controlling image quality of the moving image on the basis of the importance, and an image recorder operable to compress the taken moving image so as to obtain image quality controlled by the image quality controller, and record the compressed image in a recording medium.

Abstract: A car-mounted image recording apparatus comprises an imager operable to take a moving image of outside scene of a vehicle, an image quality controller operable to determine importance of present position of the vehicle, and controlling image quality of the moving image on the basis of the importance, and an image recorder operable to compress the taken moving image so as to obtain image quality controlled by the image quality controller, and record the compressed image in a recording medium.

Abstract: A method for signal transmission and reception by a bidirectional bus system in which plural devices performing the communication of a command and a request are interconnected over a bidirectional bus includes the steps of providing a frame of a transmission signal on the bidirectional bus the frame including an address field for designating addresses of communicating devices and a data field for designating the command or request to be transmitted, and inserting the discrimination information for discriminating between the command and the request at a pre-set position in the data field. The transmission signal including the discrimination information is transmitted over the bidirectional bus to other devices. A communication system employing such a bidirectional bus system is also provided.

Abstract: A communication protocol can communicate data among apparatus by a simple procedure efficiently. In an AV center (1) (D2B control unit (1a), for example, a communication mode thereof is set in the master transmission mode, and a packet of one frame is transmitted to a TV (2). In the TV 2 (D2B control unit (2a)), its communication mode is set in the slave reception mode. When a packet of one frame from the AV center (1) is received by the TV (2), a communication between the AV center (1) and the TV (2) is ended.