A collapsible canopy frame having an improved roof and support structure. A collapsible canopy frame according to one embodiment includes a plurality of side poles; a plurality of edge scissor assemblies coupling adjacent side poles of the plurality of side poles to one another; a center pole for supporting a covering; a plurality of center pole ribs each coupling the center pole to a respective side pole of the plurality of side poles; and a plurality of center scissor assemblies coupling the plurality of edge scissor assemblies to the center pole.