| 摘要 |
An overhead projector a base table, which has a stage on which an original is placed. A projecting head includes projecting mirror and lens, and forms an image of the original. A stand has bottom and top ends. The bottom end is mounted on the base table. The stand swings between an erected position and a folded position where the stand is superposed on the stage. The projecting head is mounted on the top end in swingable fashion. An extension coil spring is disposed between the stand and the base table, biases the stand from the folded position to the erected position, and has biasing force decreasing according as the stand comes nearer to the erected position. A gas spring is disposed between the stand and the base table, biases the stand from the folded position to the erected position, and has biasing force increasing according as the stand comes nearer to the erected position.
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