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Printer Tabulation with Proportionally Spaced Characters

IP.com Disclosure Number: IPCOM000050235D
Original Publication Date: 1982-Sep-01
Included in the Prior Art Database: 2005-Feb-10
Document File: 2 page(s) / 54K

Publishing Venue

IBM

Related People

Pascoe, RA: AUTHOR

Abstract

Since characters in imprinting done by a proportional spacing printer are not equal in size, the left edges of the characters on succeeding lines do not align with one another as they do in fixed pitch printing. A problem arises when trying to perform tablature applications in the PS (proportional spacing) environment. The problem is that the intersequence gap (ISG) created by the tab cannot be "filled" with "space" characters as there is no guarantee that this ISG is an even multiple of the space size. The solution to the problem is to provide a means of specifying an adjustment from the right edge of the last character occurring to the left of the ISG and the next column boundary and then filling the remainder of this ISG with space characters (as the width of a space character remains the width of a column in PS).

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Printer Tabulation with Proportionally Spaced Characters

Since characters in imprinting done by a proportional spacing printer are not equal in size, the left edges of the characters on succeeding lines do not align with one another as they do in fixed pitch printing. A problem arises when trying to perform tablature applications in the PS (proportional spacing) environment. The problem is that the intersequence gap (ISG) created by the tab cannot be "filled" with "space" characters as there is no guarantee that this ISG is an even multiple of the space size. The solution to the problem is to provide a means of specifying an adjustment from the right edge of the last character occurring to the left of the ISG and the next column boundary and then filling the remainder of this ISG with space characters (as the width of a space character remains the width of a column in PS). This is accomplished in the present apparatus by maintaining a fixed tab rack within the printer. This tab rack has a tab stop set at every column boundary.

In PS applications, character widths are not equal across the character set and vary over a range of widths. Additionally, the width of a space is fixed to one valve, that valve falling between the smallest and largest character width, and is equal in width to a column. In this case, the left edges of characters on succeeding lines may not align with one another as they do in fixed pitch (Fig. 1).

A problem arises when trying to perform tab...