| 摘要 |
In an overhead projector, in particular for reflective transillumination of the original to be projected, consisting of a foot which accommodates the writing plate and the Fresnel lens, a stand for the lens housing and an illuminating device, the aim is to achieve the object of providing an overhead projector by means of which it is also possible to project sections of originals without bright edge strips, and which is therefore superior to conventional projectors in terms of its subjectively perceived clarity of projection. The invention achieves this object when the foot has an arrangement of diaphragms with which it is possible to cover part of the Fresnel lens. This arrangement of diaphragms enables the lecturer to project without bright edge strips, because he can cover the bright edge strips by moving the diaphragms.
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