Patent ID: 7394462

Claim:
A superimposing apparatus for broadcasting a 3DCG image, comprising: a three-dimensional graphics accelerator for forming a 3DCG image by rendering a respective 3DCG image at each frame period; and a superimposer for forming a broadcasting image on which said 3DCG image is superimposed by mixing said 3DCG image formed by said three-dimensional graphics accelerator with a current frame of an input TV signal; said three-dimensional graphics accelerator and said superimposer are constructed to operate concurrently; wherein after the three-dimensional graphics starts to perform rendering the 3DCG image for the current frame and before the three-dimensional graphics accelerator completes rendering the 3DCG image for the current frame, the superimposer starts to mix said 3DCG image for a previous frame only with the current frame of the input TV signal, and the previous frame is immediately adjacent to the current frame by one frame.