Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Adaptive Printer Carriage Rate Limiter

IP.com Disclosure Number: IPCOM000087327D
Original Publication Date: 1977-Jan-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 3 page(s) / 76K

Publishing Venue

IBM

Related People

Bublitz, HR: AUTHOR [+3]

Abstract

An adaptive rate limiter for a printer carriage is provided by sensing the time required for advancement of one line during a skip operation and then using that time as a control factor in determining the number of lines the carriage can move in high speed skip during the next skip operation. This cyclic determination of high speed carriage advance velocity provides a continuous correction for each subsequent high speed skip. The control system does not require a time-dependent computer system, but, for example, can be used with an interrupt driven microprocessor.

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 52% of the total text.

Page 1 of 3

Adaptive Printer Carriage Rate Limiter

An adaptive rate limiter for a printer carriage is provided by sensing the time required for advancement of one line during a skip operation and then using that time as a control factor in determining the number of lines the carriage can move in high speed skip during the next skip operation. This cyclic determination of high speed carriage advance velocity provides a continuous correction for each subsequent high speed skip. The control system does not require a time- dependent computer system, but, for example, can be used with an interrupt driven microprocessor.

With certain printer carriages, paper can be advanced at a rate during high speed skip which is greater than the feed velocity of the rolls pulling the paper to the stacker. Therefore, during long skips at high speed, excess paper may be accumulated between the carriage tractors and stacking feed rolls. Accordingly, a rate limiter is required to prevent the accumulation of excess paper and to insure that all excess paper has been removed before the next print operation.

When a print and space command with a "function go" command is received, the carriage is conditioned to move at the end of the print operation. When a space command is received, the carriage is conditioned to move when a "function go" command is received. The "function go" command data field contains the number of spaces to be moved and is called the line count. The line count is the number of spaces to be moved less one for operation of the carriage for a low speed operation and the number of spaces to be moved less two for high speed skip operation.

High speed skip commands are issued only if a skip is to exceed a predetermined number of lines, such as 7. The data field of the high speed skip command contains an "H value", which is the number of lines less 1 that the carriage should remain in high speed before starting deceleration. This H value is calculated and takes into consideration the total number of lines to be moved, the number of lines that can be moved in high speed without excessive paper blousing because of the difference in carriage speed and stacking feed roll speed, and the number of lines required to decelerate and stop the carriage such that all excess paper has been removed.

The carriage rate limiter function is performed by measuring the time required for one predetermined line of skip during a high speed operation. This value is then transferred to a microprocessor after the skip operation is completed. The microprocessor then calculates an H value which is used to initiate carriage deceleration for the next high speed skip operation.

Referring to Figs. 1 and 2, the line in a high speed skip, referred to as the line count gauge for which the skip time is to be measured,...