| 摘要 |
An overhead projector shutter assembly having a frame defining a window and a number of slides movably mounted in the frame to mask the window, the slides being selectively and relatively movable to mask and unmask selected portions of the window or the entire window to project selected portions of the total transparency onto a screen in sequence. The slides are overlapped with each other and with the frame along adjacent edges to completely exclude unwanted light and to promote smoothness of operation on guides which assure accuracy of alignment between the slides and the register pins which locate the transparency.
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