Abstract: A printer for exposing photographic material is shown with a printing table horizontally mounted within a cabinet to receive photosensitive material and copy. A transparent plate is pivotably attached to hold the photosensitive material and copy in contact above the table which may be of the vacuum type. The front of the vacuum table may or may not exceed beyond the front of the cabinet. A fixed panel may be provided to support an exposing light above the table, additionally the control panel and shutter mechanism may be part of this fixed panel. A movable plate at least partially opaque to actinic rays may be moved inwardly as the transparent plate is raised. A safelight, viewing or inspection light may be mounted within the cabinet. A lifting and latching handle may be mounted at the front edge of the transparent plate.

Abstract: In the system disclosed, a transformer connected to an alternating power source establishes a continuous alternating output voltage which is connected directly across a gas discharge lamp to apply the voltage continuously across the lamp. The transformer output voltage is set within a range which includes a condition that causes the lamp to exhibit a positive impedance value when the lamp is discharging. The transformer and the source together exhibit an impedance substantially less than the impedance value of the discharging lamp.