Browse Prior Art Database

Constant Force Electro Erosion Print Stylus

IP.com Disclosure Number: IPCOM000052822D
Original Publication Date: 1981-Jul-01
Included in the Prior Art Database: 2005-Feb-11
Document File: 2 page(s) / 46K

Publishing Venue

IBM

Related People

Giordano, FP: AUTHOR [+2]

Abstract

The conventional method of adjusting stylus force is by increasing or decreasing the tension on the stylus spring. This setting is quite sensitive because too high a force results in paper burnishing while too low a force results in no printing at all. As the print wire wears, its force decreases and necessitates readjustment.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 71% of the total text.

Page 1 of 2

Constant Force Electro Erosion Print Stylus

The conventional method of adjusting stylus force is by increasing or decreasing the tension on the stylus spring. This setting is quite sensitive because too high a force results in paper burnishing while too low a force results in no printing at all. As the print wire wears, its force decreases and necessitates readjustment.

This article describes a technique which includes the use of a piezoceramic bender element to maintain a constant force on the print stylus by acting as both the force driver and the force transducer. The crystal would be cantilever mounted, as in Fig. 1, with a potential voltage difference across its outer layers. This potential difference causes one layer to expand while the other contracts with the net result of a bending displacement (x). This crystal displacement (x) in mils is equal to the voltage applied (V(A)) times the crystal constant (K) times the length (L) squared, that is, x mils = V(A)KL/2/. This equation holds true until the stylus makes contact with the paper, at which point any increase in (V(A)) is converted into stylus force. The equation for the force developed (F(f)) in grams is equal to the voltage applied (V(A)) times the crystal constant (K(f)) times the width-to-length ratio, that is, F(f) = V(A)K(f) (W over L).

With these concepts in mind the only thing necessary to determine is the point at which the stylus makes contact with the paper. Once the (V(A)) necessary to reac...