| 摘要 |
<p>The audio-visual educational device employs a slide projector (1), a mirror (2) and a transparent. Projection screen (3), supported in various relative positions via a common support frame. The latter is formed by a number of interchangeable frame elements. Pref. the educational device is combined with a school desk, with the transparent projection screen (3) lying to one side of the desk surface. The mirror (2) may be a block of depolarised glass, with a reflective surface angled at 45 degrees, directly below the projection screen (3), with the projection (1) at the same level as the glass block, to one side of the desk.</p> |
