CIRCUIT AND METHOD FOR CONVERTING SEQUENTIAL SCANNING, SETTOP BOX AND TELEVISION RECEIVER

PROBLEM TO BE SOLVED: To provide a sequential scanning conversion circuit which is ultimately advantageous in the cost by reducing the number of double speed conversion memories and reducing a circuit scale, and to provide a settop box, a television receiver and a sequential scanning conversion method. SOLUTION: In sequential conversion control, signals of a direct system and an interpolation system are switched alternately and read from a first memory, being a mass image memory storing a plurality of image signals of the direct and interpolation systems to be held in a second memory 3 being a buffer memory (memory for double-speed conversion) for reading. In double speed system separation processing, a signal read from the second memory 3 is separated between a luminance signal and a color signal to obtain double speed luminance signal and color signal, with respect to a standard television signal. The number of memories for double speed conversion can be reduced and the circuit scale can be reduced, without needing as many as four systems of memories for double-speed conversion by using the mass image memory 1 and a video processing circuit system, using a buffer memory.