| 摘要 |
<p>A secondary video signal (24) is sampled, digitized and combined with an in-memory switching signal (SS). The combined digital signal is stored in a random access video memory (900). The stored signal is read out in synchronism with the synchronizing signal components of a primary video signal. The switching signal is recovered from the output of the memory, and compared with a content code signal (CSS) to develop a fast switching signal (FSS). A video output switch (80), coupled to receive the primary video signal and the stored secondary video signal and responsive to the fast switching signal, applies an appropriate one of the two input signals to the kinescope (94) to define a secondary inset picture within a large primary picture.</p> |
