| 摘要 |
<p>A winding-unwinding means used for projection screens (1) comprises a projection screens (1) fixed to a group of shaft (2) on one end and formed a knob (11) on the other end; a group of shaft (2) with the first end provided with a spring winding-unwinding member (22) having a beaded chain (23) and the second end provided with a decelerator (24) for cushioning the resilient force of the spring winding-unwinding member (22). The user can unwind the projection screens (1) by drawing the knob (11). The projection screens (1) is wound elastically and slowly by the effect of the spring winding-unwinding member (22) and the decelerator (24).</p> |
