| 摘要 |
<p>PROBLEM TO BE SOLVED: To automatically attain switching to a receivable hierarchy when receiving quality is deteriorated even when the hierarchy with high quality is received. SOLUTION: A receiving quality judging part 108 judges a signal indicating receiving quality outputted from demodulating parts 107a-107n in each hierarchy, for example, the size of the level of an input signal or the like, and supplies information indicating the optimal receiving hierarchy to a switching part 109, and supplies information indicating that the hierarchy is switched to a mode displaying part 111, and supplies information indicating that any input video signal is not present to a monitor 113 and an LED 114, and supplies information indicating that any input voice signal is not present to an amplifier 115. When the received signal is deteriorated due to the influence of a transmission path, the switching part 109 automatically selects and outputs a signal in a hierarchy whose deterioration is small. While the output of the switching part 109 is switched to another hierarchy, the mode display part 111 adds information indicating that reception is switched to the output of the switching part 109. The output of the mode displaying part 111 is outputted to the monitor 113 and the amplifier 115.</p> |
