| 摘要 |
PURPOSE:To obtain a stable screen by inhibiting switching of an antenna when some of input signals close to the maximum level coincide with an input signal by preceding switching of the antenna. CONSTITUTION:Signals 17-19 sampled and held by a sample holding circuit 13 are inputted to level comparing circuits 20 and 41 separately. The circuit 20 detects only the highest level among input levels, but the circuit 41 detects levels close to the highest level. During level sampling, the ouput signal of a holding circuit 24 holds a last comparison signal, and a level comparison coincidence detecting circuit 45 detects whether the output signal holding the last level comparison signal is included among level comparing signal is included among level comparing output signals 42-44. When the detection results shows that it is included, the ouput of the circuit 24 holds information on the preceding level comparison as it is. Therefore, the number of times of input signal switching is decreased and a screen becomes extremely stable. |
