Patent ID: 6709175
Filing Date: 2004-03-23
Classification: B41J

Abstract:
In a thermal printer for thermal printing on a variety of types of differently shaped media items housing:a housing with a controller and internal components of the printer contained within the housing; a main chassis having ends and sides and having a print tray support mechanism and a print tray drive mechanism mounted within the sides and ends of the main chassis; a print head chassis arranged on top of the main chassis, the print head chassis having a print head unit with a thermal print head and a print head displacement mechanism that raises and lowers the thermal print head during printing operations; a print tray for media items, the print tray having a mask and retainer assembly that retains a selected one of the types of differently shaped media items during printing, the mask having a template configuration structured to compliment the configuration of the selected type of media item, wherein the tray has a tracking mechanism mounted on the print tray, the tracking mechanism being engageable with the print tray drive mechanism on installing the print tray in the printer, the tracking mechanism and drive mechanism cooperating to displace the tray into and from one end of the main chassis on the printer tray support mechanism during printing operations; the method of detecting the presence of a media in the print tray comprising: providing a retractable retainer on the print tray; providing a displaceable latching means for limiting displacement of the print tray from the printer; linking the retractable retainer and latching means; detecting displacement of the latching means; detecting displacements of the tray; and determining engagement of the retainer by detection of the displacement of the latching means at a predefined position of the tray.