It allows us to compress the distance between the projector and the screen.
这样我们就可以把投影设备和投影屏幕的距离拉近。
2
The size of the image can be adjusted simply by modifying the distance between the projector and the projection surface; the resulting image remains uniformly clear.
通过改变投影仪和投影片表面的距离，图像大小也能做简单的调整，调整后的画面仍然保持清晰。
3
Another advantage is that the pictures the overhead projector shows are large and bright owing to the short distance between the projector and the screen.