Computer driven printer

Abstract

Apparatus for maintaining tension on a ribbon in a printer used for transferring an image, e.g., thermally, from a print head through the ribbon to a print medium. By maintaining ribbon tension and thus keeping the ribbon essentially without wrinkles, print quality is enhanced. This tension maintenance apparatus uses a pair of torqued reel subassemblies with the ribbon extending between and is of particular significance when used in conjunction with a label stock as a printer medium when the printer mechanism bidirectionally moves the label stock to assist removal of labels from its backing. These torqued reel assemblies are sufficiently loaded such that ribbon tension is maintained between these reel assemblies despite this bidirectional movement.

Description

BACKGROUND OF THE INVENTIONThe present invention relates generally to printers, e.g., computer-driven, which imprint patterns from a print head through a ribbon to a print medium, e.g., paper, and in particular to printers of the type which can utilize thermal transfer ribbons. Prior art printers suitable for printing bar code labels and the like are typically comprised of 1) a thermal print head, 2) a drive roller mounted opposite to the print head, 3) a print medium subsystem including a supply reel for guiding a print medium along a path extending between the print head and the drive roller, 4) a ribbon subsystem including a supply reel and a takeup reel for guiding a ribbon along a path extending between the print head and the print medium path, 5) a spring for urging the print head toward the drive roller to pinch the print medium and the ribbon therebetween and 6) a motor mechanism for causing the drive roller to move the print medium and the ribbon in either a forward or a re...

AI Technical Summary

Benefits of technology

The present invention is directed to a printer apparatus particularly configured to maintain tension on a ribbon to prevent ribbon wrinkling regardless of the direction the ribbon is moved.

In accordance with a further aspect of the invention, a preferred printer facilitates loading of a print medium, e.g., paper, and a ribbon which both pass between a print head and platen. To facilitate loading, a preferred printer apparatus is formed using a clam shell housing comprised of two assemblies that are rotatably coupled at a first end and are latchable at a second end. The first assembly includes the platen and the second assembly includes the print head such that when the two assemblies are unlatched and rotated apart, feed paths for the print medium and the ribbon are accessible to an operator.

Problems solved by technology

However, when the drive motor reverse direction, the accumulated torque in the supply reel accumulation device urges rotation of the supply reel that is resisted by the takeup reel accumulation device.

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