Browse Prior Art Database

Journal Roll Take-Up Compensation Method and Apparatus

IP.com Disclosure Number: IPCOM000047424D
Original Publication Date: 1983-Nov-01
Included in the Prior Art Database: 2005-Feb-07
Document File: 3 page(s) / 48K

Publishing Venue

IBM

Related People

Harris, RH: AUTHOR [+2]

Abstract

Point-of-sale terminal devices normally contain a journal roll printer. The journal printer utilizes a roll of paper tape to print a chronological record of transactions at the terminal. Journal printers normally feed the roll media past the printing station in either one of two methods: 1) Fixed line spacing is produced at or near the print line with the take-up spool being overdriven through a slip clutch to provide a continuous tension on the take-up side. This method permits the full roll of paper to be taken up with consistent line spacing but requires an escapement at or near the print line to permit paper to pass. This involves a more complex paper loading path than is desired in some instances.

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 46% of the total text.

Page 1 of 3

Journal Roll Take-Up Compensation Method and Apparatus

Point-of-sale terminal devices normally contain a journal roll printer. The journal printer utilizes a roll of paper tape to print a chronological record of transactions at the terminal. Journal printers normally feed the roll media past the printing station in either one of two methods: 1) Fixed line spacing is produced at or near the print line with the take-up spool being overdriven through a slip clutch to provide a continuous tension on the take-up side.

This method permits the full roll of paper to be taken up with consistent line spacing but requires an escapement at or near the print line to permit paper to pass. This involves a more complex paper loading path than is desired in some instances. 2) The medium is fed by means of a large diameter take-up spool with the large starting diameter being required to limit the line spacing variation between the empty and full roll condition from being excessive. This produces a minimum line space variation by incrementing the take-up reel by equal amounts but does limit the amount of paper to be taken up to less than a full roll because of the greater diameter produced.

Both of these prior methods have sensors for detecting the full take-up roll or end of paper conditions. This article discloses a simple method of feeding the medium by means of a take-up spool, as described in the second method above, with the ability of a full roll to be taken up, as described in the first method, and at low cost. Turning to Fig. 1, paper 1 is fed from a supply roll 24 through a paper path passing between a platen 4 and a nosepiece 5 of a print head to a take-up spool 2. The take-up spool 2 has a one-inch or less diameter and is driven by a low cost large stepping angle DC stepper motor 12 or the like. A transmission in the form of a timing belt and pulleys (not shown) is sized such that a relatively large number of motor steps, 20 or more, will produce one line space of paper motion at the platen 4. Line spacing of the minimum acceptable spacing at approximately 7-1/2 lines per inch with 20 motor steps is a typical design figure. A pivoted sensing level 6 pivoted in a journal 13 has a follower end 6A that tracks the increasing diameter of the take-up spool 2. As paper is wound onto the take-up spool to its full diameter 3, the follower arm 6 gradually moves to the position shown as position 6B. A sensor arm 8 is rigidly affixed and moves with the rotation of the shaft to which arm 6 is mounted. A sensing flag 8A on the distal end of arm 8 moves past a light-emitting diode (LED) and photosensor array 9, consisting of two positions with matching LEDs and phototransistors 10 and 11. The sensing flag 8A is notched to produce a series of logic signals as it passes through the sensor 9. As lever 8 rotates, four logic states of [10, 11], [10, 11], [10, 11], [10, 11] are produced. A sensor 9 having more channels will provide finer resolution. However,...