COMMUNICATION DEVICE AND COMMUNICATION SYSTEM

PROBLEM TO BE SOLVED: To provide a communication device and communication system where efficient retransmission is carried out. SOLUTION: The communication device has: an image data receiving means for receiving image data; a first error checking means for checking errors per frame unit in the image data received by the image data receiving means; an image data extension means for extending the image data received by the image data receiving means when an error is confirmed by the first error checking means; and a second error checking means for checking the errors per line unit in the image data extended by the image data extension means. In the communication device, a line retransmission request signal which not only includes the number of the frame with a line where there is the error and information with respect to the number of the line in the frame, but also requests the retransmission per line unit of the line where there is an error, is transmitted to the communication device which has transmitted the image data when the line where there is the error is confirmed by the second error checking means. COPYRIGHT: (C)2011,JPO&INPIT