Browse Prior Art Database

Universal Escapement Calibration Mode

IP.com Disclosure Number: IPCOM000044194D
Original Publication Date: 1984-Nov-01
Included in the Prior Art Database: 2005-Feb-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Stephan, RL: AUTHOR

Abstract

At start up, a homing operation moves a carrier of a typewriter to the left until no further motion of the carrier is detected, such as by an optical encoder. This location of no movement to the left of the carrier is defined as the zero location. All absolute positioning of the carrier is referenced to this zero location. The carrier may have been prevented from moving to the actual location of the left frame at start up by an obstruction, for example, so that this zero location was actually in the middle of the writing line, for example. As a result, if a tab operation were to occur next without any tabs being set, the carrier would be driven at a high speed into the right frame because the writing line would have been measured from the actual location of the left frame whereas this was not the zero location.

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Universal Escapement Calibration Mode

At start up, a homing operation moves a carrier of a typewriter to the left until no further motion of the carrier is detected, such as by an optical encoder. This location of no movement to the left of the carrier is defined as the zero location. All absolute positioning of the carrier is referenced to this zero location. The carrier may have been prevented from moving to the actual location of the left frame at start up by an obstruction, for example, so that this zero location was actually in the middle of the writing line, for example. As a result, if a tab operation were to occur next without any tabs being set, the carrier would be driven at a high speed into the right frame because the writing line would have been measured from the actual location of the left frame whereas this was not the zero location. To avoid this, the carrier is moved to the right immediately upon the encoder detecting no movement to the left. This motion is continued until the encoder detects no further movement to the right. The distance between the zero location and the frame or other obstruction stopping movement of the carrier to the right is the usable writing line. This value of the usable writing line could be compared with a known value to determine whether the true left and right frames stopped movement of the carrier or whether an obstruction stopped movement of the carrier. This also would insure that no writing line would be attempted...