Browse Prior Art Database

Printhead Actuating Mechanism

IP.com Disclosure Number: IPCOM000049194D
Original Publication Date: 1982-May-01
Included in the Prior Art Database: 2005-Feb-09
Document File: 2 page(s) / 55K

Publishing Venue

IBM

Related People

Craft, JA: AUTHOR [+2]

Abstract

A positioning mechanism for a column matrix printhead provides for two printhead positions, withdrawn from the print line, that afford different degrees of print line visibility. Movement to the highest visibility position is preferably conditioned on the amount of time elapsed since the last keyboard printing operation.

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Printhead Actuating Mechanism

A positioning mechanism for a column matrix printhead provides for two printhead positions, withdrawn from the print line, that afford different degrees of print line visibility. Movement to the highest visibility position is preferably conditioned on the amount of time elapsed since the last keyboard printing operation.

Referring to the figure, the positioning mechanism 8 comprises a solenoid 10 with dual plungers 12 and 14 which actuate at different voltage levels (e.g., 12 and 24 volts). Plungers 12 and 14 are connected to a positioning arm 16 and a pivot member 18. A non-magnetic sleeve 20 is pressed into the hollow central portion of the outer plunger 12, and the inner plunger 14 is arranged to slide within that sleeve.

The positioning arm 16 and pivot member 18 are connected for relative rotation at a pivot pin 26. A printhead 22 interacts with the pivot member 18 at a pin 24 and is connected for rotation relative to the positioning arm 16 by a bracket 28 and a pivot pin 30. The pivot member 18 is biased toward the positioning arm 16 by a spring 32 connected therebetween.

In operation, with 0 volts applied, both plungers 12 and 14 are at released positions and the printhead 22 assumes the position of greatest withdrawal (shown in dashed lines) from platen 34. With 24 volts applied, both plungers 12 and 14 are at the sealed positions and the printhead 22 assumes slightly withdrawn position (solid lines). By applying 12 volts, on...