Patent ID: 6141029
Filing Date: 2000-10-31
Classification: B41J

Abstract:
In a thermal transfer franking printer having a thermal print head with a plurality of thermal print elements, operated by power electronics and controlled by a control unit to generate respective franking imprints of equal size on a medium by thermally transferring ink from an inking ribbon to the medium by energization of selected print elements by said control unit and thereupon also leaving respective imprints on said inking ribbon, said inking ribbon being contained in a cassette which is releasably engageable with said thermal print head and said inking ribbon being unwound from a supply reel in said cassette and wound, after printing a franking imprint, being wound onto a take-up reel in said cassette, the improvement of an arrangement for identifying an end of said inking ribbon, comprising:an encoder disposed to measure passage of said inking ribbon which emits an electrical signal indicating a length of said inking ribbon which has passed said encoder;a counter, disposed remote from said thermal print head and which receives said electrical signal directly from said encoder independently of said cassette, which counts a number of said franking imprints of equal size produced on said inking ribbon by said thermal print head as indicated by said electrical signal, and which emits a signal indicating an end of said inking ribbon after a predetermined number of said franking imprints of equal size on said inking ribbon.