Browse Prior Art Database

Elimination of Overprinting on Ledger Cards

IP.com Disclosure Number: IPCOM000074353D
Original Publication Date: 1971-Apr-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Knowlden, EI: AUTHOR [+2]

Abstract

Overprinting on ledger cards when a printed Line Finder Mark is sensed to determine the location of the next line is often caused by the previous Line Finder Mark being out of registration because of changes in the card size resulting from temperature and/or humidity changes between runs.

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Elimination of Overprinting on Ledger Cards

Overprinting on ledger cards when a printed Line Finder Mark is sensed to determine the location of the next line is often caused by the previous Line Finder Mark being out of registration because of changes in the card size resulting from temperature and/or humidity changes between runs.

This can be prevented by reading the previous Mark or Marks and using logic circuitry to establish timing intervals or windows during which the next Line Finder Mark should appear. By determining whether a previous Mark is centrally located or is low in the corresponding window as in A, it can be determined whether the registration of the next line will fall within the desired registration limits or whether to skip to the next line space before printing, so as to prevent over-printing of a previous line.

Shown at B is logic circuitry for determining the relative location of the last Line Finder Mark. The main function of the circuit is to locate the next available line on a ledger card for posting.

A Start I/O command sets a Drive Latch 10 which is reset when the next available line is detected by the absence of a Line Finder Mark which is printed at the end of each completed line of printing on the ledger card. Two missing Marks are detected by means of a 1st Miss Latch 12, and a 2nd Miss Latch 14 before determining the location of the next line.

A Late Mark single-shot 16 is provided to time the Line Finder Marks being sensed. A nomi...