Color filter interpositioning mechanism for color electrophotography

Abstract

A color filter interpositioning mechanism for use in an electrophotographic print mechanism which uses motor driven pulleys to move a belt which is located directly beneath a grooved track into which the color filter assemblies are inserted. The belt contains spaced apart holes which are brought beneath the color filter assemblies, by the rotation of the belt about the pulleys, thus allowing a spring loaded pin, attached to each filter, to fall through a slot in the grooved track and into the hole. The filter assembly is then drawn down the track and into an optical path. A sensor detects when the filter is properly positioned in the optical path and signals the motor to stop. An image of the original to be copied is then projected through the filter and onto a photoreceptor. After the image is shot, the belt begins to move again and the forward-most pulley pushes the spring-loaded pin back into its housing, allowing a retracting spring attached to the color filter assembly to draw the assembly back down the track into its original position. This process is repeated for all the color filter assemblies before transfer of the image to an image receptor and the completion of copying process. The use of the belt and sensor system dispenses with the need for finely machined parts and this in combination with the retracting spring allows the whole mechanism to be much smaller, thus allowing for a much smaller print mechanism.