Patent ID: 6682239
Filing Date: 2004-01-27
Classification: B41J

Abstract:
A thermal printer unit comprising:a thermal head assembly; and a platen roller, wherein: said thermal head assembly comprises: a frame having platen roller receiving parts receiving both ends of said platen roller, respectively; a thermal head mounted on said frame; and a spring member mounted on said frame and applying a head pressure to said thermal head, wherein each platen roller receiving part comprises: a vertical groove part having an opening at the top thereof; a horizontal groove part extending from the bottom of said vertical groove part in a direction such as to be away from said thermal head; and a projection part formed relatively by said vertical groove part and horizontal groove part, located above said horizontal groove part, and projecting from a depth part of said horizontal groove part toward said thermal head, and wherein both ends of said platen roller are inserted into the horizontal groove parts of said platen receiving parts, respectively, and, also, are pressed by said spring member over said thermal head into the depth parts thereof, respectively; and wherein said thermal head is obliquely provided so that said thermal head is pressed onto said platen roller by said spring member, thereby preventing said platen roller from being moved upward unless an external force of predetermined magnitude is applied to said platen roller to move said thermal head against a resilient force of said spring member.