| 摘要 |
A film is placed on a front surface of a pressure plate. The pressure plate has, at its central portion, a plurality of small through-holes through which the film is sucked to provide sufficient flatness of the film during each exposure. A closed variable space is formed in the rear of the pressure plate by a variable container including the central portion of the pressure plate. The film is sucked by increasing the volume of the closed variable space by means of an electromagnetic actuator which comprises a moving coil mounted on the variable container at its rear side and a fixed permanent magnet providing a magnetic field for interaction with the moving coil. The actuator is driven by a drive circuit.
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