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Browse Prior Art Database

Test Score Form

IP.com Disclosure Number: IPCOM000074082D
Original Publication Date: 1971-Mar-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 35K

Publishing Venue

IBM

Related People

Brackett, DW: AUTHOR [+2]

Abstract

This is a precoated sheet on which is printed, in invisible ink, data chemically developable by a pen-applied reagent to produce within a test score block human readable text in one color and background in a different color; both colors being indistinguishable from each other and read as one by an optical mark reader (OMR) device.

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This is the abbreviated version, containing approximately 100% of the total text.

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Test Score Form

This is a precoated sheet on which is printed, in invisible ink, data chemically developable by a pen-applied reagent to produce within a test score block human readable text in one color and background in a different color; both colors being indistinguishable from each other and read as one by an optical mark reader (OMR) device.

Paper sheet 1 (or web) has one entire face 2 coated with one reactant by a conventional coater or size press. Then within defined printed mark-sense areas 3, answer or text information 4 is printed with an ink containing a second reactant. The ink is either clear or the same color as the background so information 4 is initially invisible. Student selectively develops areas 3 with a writing pen containing a third reactant that reacts with 4 to provide one color (e.g., black) and with the remaining background portion 5 of 3 to provide another color (e.g., red), distinctive enough so the student can read 4 against background
5. However, OMR device will sense both colors as if they were one; e.g., read 4,5 of each developed area 3 as if it were completely black. As examples of the reactants for coating on 2, use an inorganic cupric salt to supply Cu+2 ions; in ink for 4, use an inorganic stannous salt to supply Sn+2 ions; for pen-applied developer, use solution of sodium rhodizonate and diphenyl carbazone to give these reactions:

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