Abstract: A method and apparatus for precisely aligning two photo printing plates with each other by placing a light emitting laser diode on one side of one of the photoprinting plates and a photo diode that provides coordinate information on the other photoprinting plate so that when the laser beam from the laser emitting diode is directed through the photoprinting plates to the photo diode, the coordinate information on excited point on the photo diode can be compared to a reference signal to generate a control signal to activate motors that position the photoprinting plates in the proper position with respect to each other.

Abstract: Apparatus for temporarily hinging the lower portion of oppositely disposed photoprinting plates to enable decoupling the hinged top portions of the photoprinting frames so that the photoprinting frames can be pivoted toward a horizontal position to easily facilitate replacement of the photoprinting glass plates in the photoprinting frames.