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: 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 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. The invention comprises a clutch disk made of plastic, which may be used in a printer mechanism. The design utilizes two different injection molded plastic clutch disks that run face to face to produce relatively high dynamic and low static frictional forces. The clutch assembly uses raised areas on one of the pair of clutch disks. The raised areas allow a better overall contact between the disks so as to achieve more desirable coefficients of friction. The materials chosen for the clutch disks not only have the desirable coefficients of friction, but also have good wear characteristics against each other.

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. The invention comprises a clutch disk made of plastic, which may be used in a printer mechanism. The design utilizes two different injection molded plastic clutch disks that run face to face to produce relatively high dynamic and low static frictional forces. The clutch assembly uses raised areas on one of the pair of clutch disks. The raised areas allow a better overall contact between the disks so as to achieve more desirable coefficients of friction. The materials chosen for the clutch disks not only have the desirable coefficients of friction, but also have good wear characteristics against each other.