摘要 |
A magnification-variation scanner modifies the resolution merely by changing the object distance and the image distance, with a constant focal distance. The scanner includes a light source, an object lens, an image detector, a holder for carrying the object lens, an optical path delay and a driver. The optical path delay can be located at the midway of the light path from the light source to the object lens, thereby modifying the optical path between the object surface and the object lens. In accompaniment with the movement of the object lens, the dimensions of the image projected over the image detector can be modified. The resolution can therefore be modified. The driver connects between the holder and the optical path delay. As the movements of the holder and the optical path delay are controlled by the driver, the optical path from the object surface to the object lens and that from the object lens to the image detector can be modified according to the equations of
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