| 摘要 |
PURPOSE:To superpose a converted signal in horizontal scanning periods and reproduce it while preventing signal deterioration and absence by storing a memory temporarily with plural packet data of a text signal superposed in vertical blanking periods of a composite video signal, and converting the array of each data, byte by byte. CONSTITUTION:The 1st text signal superposed in vertical blanking periods of the composite video signal from a composite video signal input terminal 101 is sampled by a synchronous separating circuit 102, gate pulse generating circuit 103, sampling circuit 104, etc., under the control of a CPU107. The sampled text signal is stored in the buffer memory 105 temporarily. The array of data in each packet of the text signal stored in a memory 105 is converted, byte by byte, by a counter 106, superposition gate generating circuit 111, etc., and the 2nd text signal is stored in a main memory 110. Then, the text signal is superposed in plural horizontal scanning periods in the vertical blanking period of the composite video signal to prevent the deterioration and absence of the signal during reproduction. |
