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Print Performance Improvement for Resistive Ribbon Correcting Printer

IP.com Disclosure Number: IPCOM000036487D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 3 page(s) / 70K

Publishing Venue

IBM

Related People

Baker, RW: AUTHOR [+2]

Abstract

It has been found that in a correcting resistive ribbon, thermal typewriter increasing the head force improves print quality and abrasion resistance but adversely affects correction performance. This has been demonstrated with a standard head-force mechanism in which the head force at correction is higher than the force at print. It is also (Image Omitted) known that correction performance improves if the force at correction is equal to the force at print and improves even further if the correction force is less than the print force.

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Print Performance Improvement for Resistive Ribbon Correcting Printer

It has been found that in a correcting resistive ribbon, thermal typewriter increasing the head force improves print quality and abrasion resistance but adversely affects correction performance.

This has been demonstrated with a standard head-force mechanism in which the head force at correction is higher than the force at print.

It is also

(Image Omitted)

known that correction performance improves if the force at correction is equal to the force at print and improves even further if the correction force is less than the print force.

Fig. 1 is a plan view of a standard head force mechanism during printing. The printhead 1 is in contact with platen 2 and the correction roller 3 is disengaged from platen. An extension spring 4 is anchored at one end to the head pivot 5 and at the other end to a bracket 5a attached to the correction roller. The clockwise (CW) torque generated by the spring about the center of rotation of the head pivot is counteracted by a counter-clockwise (CCW) torque generated by the force of the platen on the electrode tips (the head force). The head force is nominally 200 grams.

Fig. 2 shows the standard mechanism during a correction cycle. The correction roller 3 is in contact with the platen and the extension spring 4 has been lengthened. As a result, the head force at correction is 20 to 40 grams more than the force at print. This degrades the correction performance.

Figs. 3 and 4 illustrate one embodiment of this improved mechanism in which the print force and correction force are equal. The mechanism is shown in the print position in Fig. 3. The standard spring has been removed and a new head spring 6 is attached at one end to the head pivot 5 and at the other end to a stationary bracket 7 mounted to the carrier (not shown). This spring provides a head force of 280 20 grams. A second spring 8 is anchored at one end to the bracket 5a of correction roller 3 and at the other to the carrier frame. It controls the correction roller velocity when the roller impacts the platen during a correction cycle and also aids in returning the entire head mechanism to the home position after a print cycle (the head spring 6 is elongated when the mechanism returns to the home posi...