| 摘要 |
<p>An input processing section (1 - 7) outputs a digital signal corresponding to a frequency sweep range of an input signal. A memory (8) stores the digital signal. A display (9) displays the digital signal stored in the memory (8) as an image which is developed along a frequency axis. A scroll command section (20) provides a command for shifting the image. A controller (10) supplies, to the input processing section (1 - 7), a first control signal for causing the input processing section (1 - 7) to process the input signal in a first frequency sweep range and supplies, to the memory (8), a second control signal for causing the memory (8) to store the digital signal, prior to reception of the command. When the command is received, the controller (10) supplies, to the input processing section (1 - 7), a third control signal for causing the input processing section (1 - 7) to process the input signal in a second frequency sweep range in accordance with a content of the command and supplies to the memory (8), a fourth control signal for causing the memory (8) to store the digital signal. The display (9) displays an image of the second frequency sweep range to be continuous with the image of the first frequency sweep range which is shifted in accordance with the command.</p> |
