| 摘要 |
<p>A vector CRT display apparatus for faithfully reproducing an analog signal having high frequency components include an A-D converter, a digital minimum/maximum circuit and a recirculating shift register to derive from the signal, in successive sampling periods, two digital words representing, respectively, a minimum amplitude value date point and a maximum amplitude value data point of the signal. In each sampling period, the minimum/maximum circuit stores in the memory the most relevant of the minimum and maximum amplitude values and determine whether the remaining values should be held over to the next sampling period before it is stored, or can be discarded. As a result, if new minimum and new maximum amplitude values occur in the same sample period, one will be loaded into the memory and the other will be held over and loaded into the memory in the next sample period. By storing only the most relevant of the minimum and maximum amplitude values, the size of the memory required, and its cost are substantially reduced; additionally, the storage of only important values in the memory for later display contributes to a uniformity of brightness of the display.</p> |
