Patent Number: 6,254,292

Title: Pin-supported and -aligned linear encoder strip for a scanning incremental printer

Abstract: Spaced pins support and align the strip. Apertures in the strip engage the pins with no fastening. The strip--best a transparent member and glued strength member--is end-mounted and -tensioned. Ideally the apertures are slots to constrain the strip as to only one dimension, and spaced (ideally about 30 cm on centers) to facilitate cutting various-size strips (e. g. for spans of roughly 911/2, 1061/2, 1521/2 and 183 cm) from common, preapertured stock. The strip is longer than a meter; the invention is progressively more valuable for 11/4 m or longer strips. At least one pin is placed to keep fundamental oscillation of the strip, due to environmental vibration, from moving the strip out of position. The invention can take the form of the strip only, for use with the pins; or a printer with encoding system having the strip and pins--and a sensor responsive to the encoder to control printing; or a method of preparing a system for use. The pins prevent the strip from leaving the sensor and permit use of very low tension--only that needed to hold up the strip, within its vertical-alignment tolerance, over a short span between pins. The tension, and thereby the vertical-dimension stack from encoder scale to sensor, are thus made virtually independent of encoder-strip length. Such a printer ideally has a printhead carriage that scans parallel to the strip; the sensor (adjacent to the strip and carried on the carriage) develops signals representing position and velocity of the sensor and carriage relative to the strip. Printheads on the carriage form color marks to construct an image on a print medium. A medium-advance mechanism provides relative motion between carriage and medium. A processor responds to the position/velocity signals, and coordinates the printheads and advance mechanism to form the image.

Inventors: Navarro; Emilio Angulo (Sant Cugat del Valles, ES)

Assignee: Hewlett Packard Company

International Classification: B41J 19/20 (20060101); B41J 029/42 ()

Expiration Date: 07/03/2018