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Guidelines for Mark Sensing, Printed with Phosphorescent Ink

IP.com Disclosure Number: IPCOM000094591D
Original Publication Date: 1965-Mar-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 30K

Publishing Venue

IBM

Related People

Van Steenis, H: AUTHOR

Abstract

Phosphor-containing inks are used for printing guidelines or backgrounds on mark-sensing documents. In the scanner, besides the visible light source, an ultraviolet radiation source is used for stimulating the phosphor. Thus, the guidelines or backgrounds are made to appear as reflective as the base paper, or even more so.

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Guidelines for Mark Sensing, Printed with Phosphorescent Ink

Phosphor-containing inks are used for printing guidelines or backgrounds on mark-sensing documents. In the scanner, besides the visible light source, an ultraviolet radiation source is used for stimulating the phosphor. Thus, the guidelines or backgrounds are made to appear as reflective as the base paper, or even more so.

In the first case, the guidelines are made to show better contrast to the human eye, while for the scanner the absorption of visible light by the guidelines is balanced by the emission of the phosphor. Hence, the guidelines are not apparent to the scanner.

In the second case, where the phosphorescent ink has a higher light output than the base paper, this has the further effect of realizing automatic registration. Drawing 1 shows an example of constrained handwriting in which the box and the two dots are preprinted in phosphorescent ink and the numeral is written in normal ink. The scanning signal obtained along the path 1...7 is shown in drawing 2. The signal has negative peaks 1, 3, 5 and 7 where phosphor is sensed. It has positive peaks 2, 4, 6 where normal ink is sensed. The four negative. peaks indicate a well-registered scan.

The positive peaks indicate character crossings. If only ultraviolet irradiation is used and the whole area of the box carries phosphorizing background printing, the signal of drawing 3 is obtained along this same path. The normal ink of the character absor...