| 摘要 |
<p>The invention provides a portable screen assembly that is lighter in weight and easier to handle. The assembly includes a casing, a spring-biased roll rotatably amounted to the casing, a screen bonded at one end thereof to a top bar and wound around the spring-biased roll when in storage, and an expanding and contracting means having one end rotatably mounted to an mounting member mounted to the top bar and the other end rotatably mounted to the casing. For the expanding and contracting means is used a half- pantograph type expanding and contracting means having a first arm, a second arm and a third arm arranged in an extended plane parallel to the extended screen, the second arm including two or more mutually parallel sub arms provided to be mutually parallel in the extended plane, the two or more sub arms being connected to the first arm and the second arm so as to form a parallel link.</p> |
