US Patent 7530750 Photo printer with a vertically transmitted platen roller

In a photo printer, with a translating cam at a horizontal displacement, a platen roller can be lifted up/down vertically to/from a print head. On the profile of the translating cam, there is plurality of concave surfaces and a convex surface as a follower's path. A platen roller frame is used for supporting the platen roller. As the translating cam moves in the track, the roller installed on the platen roller frame rotates on the translating cam's profile. Following the variation of the translating cam's profile, the platen roller frame carries the platen roller to move vertically, so that the platen roller can move to/from the print head in straight line.