Abstract: Various edge detection arrangements are disclosed, including an edge detection method and arrangement that utilizes outputs of commonly illuminated reference and edge sensors as the inputs for a comparator. The reference sensor is configured to have a wide field of view and the edge sensor is configured to have a narrow, high gain, field of view. Therefore, the reference sensor has a broad signal response to an edge passage and the edge sensor a steep and narrow signal response. When the two signals are biased to cross each other, the comparator output changes state, indicating passage of an edge. Because the reference sensor provides a base signal level directly related to the real time illumination level that the edge sensor also receives, the reference sensor provides a switch point along the transition ramp of the edge sensor that integrates a majority of the random error sources.

Abstract: A quick-release printhead mounting assembly and thermal printer incorporating same, including a printing component, a printer housing, and, a component retention feature attached to or molded into the printer housing adapted for receiving and releasably fixing the printing component to the housing. The retention feature holds the printhead in a fixed position relative to the housing and, therefore, also relative to the platen of the printer. The printing component is advantageously a printhead, such as a thermal printhead, or the combination of a thermal printhead and a heat sink.

Abstract: A system for dissipating electrostatic charge build-up in printers comprises a ribbon frame made of statically dissipative material and adapted to support a printhead bracket on which a thermal printhead is mounted proximate to a rotating platen. The statically dissipative ribbon frame may be grounded to the printer power supply which in turn is grounded to the main printed circuit board assembly (PCBA) of the printer which is connected to earth ground. The electrostatically dissipative material in the ribbon frame automatically dissipates static electric charge as the moving ribbon comes into physical contact with at least one portion of the grounded ribbon frame during printer operation. The printhead bracket may also be made of statically dissipative material and grounded to the PCBA. The electrostatically dissipative material in the printhead bracket automatically dissipates static electric charge as the moving ribbon comes into physical contact with at least one portion of the grounded printhead bracket.

Abstract: A ribbon mechanism mounted in the lid of a printer includes a ribbon carriage pivotally coupled to the lid for folding out of the lid by virtue of its mass when the lid is open and for folding in the lid as the lid is closed. A gear train is mounted on the ribbon carriage for driving the ribbon take up core. A thermal printhead is resiliently mounted in the ribbon carriage and automatically aligned against the platen with alignment tabs. The ribbon carriage is movably linked to a printer hinge by way of a linkage having an elongated slot at one end for slidably engaging an integral ribbon carriage post and with an aperture at the other end for pivotally mating with a lever arm provided on the printer hinge. The ribbon carriage post slides linearly inside the linkage slot between maximum “down”/maximum “up” positions at each end of the linkage slot, respectively.

Abstract: A system for dissipating electrostatic charge build-up in printers comprises a ribbon frame made of statically dissipative material and adapted to support a printhead bracket on which a thermal printhead is mounted proximate to a rotating platen. The statically dissipative ribbon frame may be grounded to the printer power supply which in turn is grounded to the main printed circuit board assembly (PCBA) of the printer which is connected to earth ground. The electrostatically dissipative material in the ribbon frame automatically dissipates static electric charge as the moving ribbon comes into physical contact with at least one portion of the grounded ribbon frame during printer operation. The printhead bracket may also be made of statically dissipative material and grounded to the PCBA. The electrostatically dissipative material in the printhead bracket automatically dissipates static electric charge as the moving ribbon comes into physical contact with at least one portion of the grounded printhead bracket.