Production Of An Optical Step Wedge In Lithographic Emulsion
Original Publication Date: 1979-Feb-01
Included in the Prior Art Database: 2005-Feb-19
The procedure described below can be used economically and reliably to produce a desired glass master. 1. An unexposed lithographic emulsion glass plate or film is placed in a contact fixture with the emulsion side up. 2. A suitable ultraviolet filter is placed on top of the glass. 3. The step wedge can be produced by two methods: a) Varying the intensity of light striking the emulsion at expose time. This is traditionally accomplished by placing a step wedge between the light sources and the emulsion. b) Varying the time of exposure at different points or areas on the emulsion.