叙述了目前所使用ＰＰＩ显示器上的传统空心、延时方式的不足之处，提出了多级扩展、屏外偏心、量程连续可变的显示方式，并且给出了实现框图和算法。

This paper describes the shortcomings of hollow and delay in the PPI display mode, puts forward the new idea of the multi-expansion, the origin-off-indicator expansion and the range continuous change, and provides the diagrams and algorithm to the solution.

TN957.7