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Proportional Space Print Control

IP.com Disclosure Number: IPCOM000044494D
Original Publication Date: 1984-Dec-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Ringle, TW: AUTHOR [+2]

Abstract

In a printer that prints while the carrier is stopped, the print sequence in a fixed pitch (FP) character mode is 'print-escape-(wait for next character)-print-escape.' In a proportional space (PS) character mode, it is necessary to alter the print sequence to 'escape-print-escape-(wait for next character)-escape-print-escape' because the escapement to print the PS character in the center of its character box is based on the width of the character to be printed. For example, a 14 units wide "m" requires 7 units of escapement prior to print while a 6 units wide "i" requires only 3 units of escapement prior to print. While this sequence works satisfactorily at slow printer speeds, the print speed is reduced significantly in comparison with the FP mode.

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Proportional Space Print Control

In a printer that prints while the carrier is stopped, the print sequence in a fixed pitch (FP) character mode is 'print-escape-(wait for next character)-print-escape.' In a proportional space (PS) character mode, it is necessary to alter the print sequence to 'escape-print-escape-(wait for next character)-escape-print-escape' because the escapement to print the PS character in the center of its character box is based on the width of the character to be printed. For example, a 14 units wide "m" requires 7 units of escapement prior to print while a 6 units wide "i" requires only 3 units of escapement prior to print. While this sequence works satisfactorily at slow printer speeds, the print speed is reduced significantly in comparison with the FP mode. This is because the algorithms used for carrier motor motion control do not allow two short moves to be executed as quickly as one move which is the total of the two short moves. By using a print sequence in a PS mode of 'escape-print-(wait for next character)-escape-print-(wait for next character)-escape,' print speed for the PS mode of printing can be at the same speed as for the FP mode of printing. This is accomplished by having the first escapement in the print sequence be 1/4 of the character width of the first character to print. The second escapement is 1/4 of the character width of the first character plus 1/4 of the character width of the second character when the second character to be printed is received prior to the expiration of a fixed time-out. All sub...