| 摘要 |
The invention relates to a device for facilitating the handling of transparencies to be projected by an overhead projector. The device includes a support frame which can be secured by adhesive means to the light table of a projector. A transparency is placed on the support frame, and extends across an aperture in the frame through which light is projected upwardly. An aperture cover which encloses the support frame is mounted thereon for reciprocating movement between a position covering the aperture to a position exposing the aperture. Accordingly, the aperture cover enables the projected light to be interrupted when a transparency is being changed on the support frame.
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