| 摘要 |
In a cover (1) for overhead transparencies (not shown) and consisting of a pocket (2) with ring file holes (9) and a non-transparent mask flap (3) to cover the part of the light plate of the projector which is not covered by the pocket (2), the novelty is that the mask flap (3) is hinged to the pocket (2) at the edge which is opposite the edge with the ring file holes (9). This provides a plurality of advantages, e.g. - that the cover is easy to manufacture and therefore inexpensive, and - that the opposite side of the mask flap may be used as an index leaf for the cover when it is placed by means of the holes (9) in a ring file (not shown) together with several other covers of the same type. |
