Label printer with label edge sensor

Abstract

A label printer includes a thermal print head assembly for printing pressure sensitive adhesive-backed labels spaced longitudinally on a web. The print head assembly includes a row of heater elements aligned transversely of the web path and movable toward and away from the web, the heater elements being biased against the web. Mechanical displacement of the print head assembly due to the passage of the leading and trailing edges of the labels beneath the heater elements is sensed by a piezoelectric sensor carried by the print head assembly to locate the printing on the labels with respect to the edges. The sensor may be mounted directly on a pivoting print head or may be mounted on a pivoting support or bracket which carries the print head. The print head assembly may be of the thermal printing or thermal transfer printing type. Both individual and stacked piezoelectric ceramic transducer elements are disclosed.

Dependencies are inferred from the claim text.