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Method of Detecting Document Skew

IP.com Disclosure Number: IPCOM000096011D
Original Publication Date: 1964-Nov-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 2 page(s) / 28K

Publishing Venue

IBM

Related People

Hoefs, GH: AUTHOR [+2]

Abstract

The occurrence and degree of document misalignment in a machine reading station can be determined dynamically. Such is effected by processing test documents preprinted with a pattern of contrasting machine readable marks in a specific location on the document.

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Method of Detecting Document Skew

The occurrence and degree of document misalignment in a machine reading station can be determined dynamically. Such is effected by processing test documents preprinted with a pattern of contrasting machine readable marks in a specific location on the document.

The test documents are preprinted with groups of marks being successively misaligned in the scanned areas of the documents. The marks can be printed with ink suitable for magnetic or optical sensing. In A, document 1 is printed with groups of marks 2 alternately positioned along the top or bottom of scan area 3. Fields are defined by control markings such as characters 4. The document is passed under sensing head 5. This reads an equal number of marks in each group in the scan area, if document alignment is proper. Head 5 reads unequal groups, when the document is improperly transported.

The marks on a document can be also arranged in a different configuration as in B. Two groups of marks 7 are arranged in a V-configuration on document 8. A character 9 can be used to define a field. During transport of the document under the sensing head, any skew produces unequal counts in the groups. Vertical misregistration produces an abnormal count in each group. Either of the mark arrangements can be used to produce machine responses which show the presence and degree of transverse misalignment and skew and indicate the corrective action required.

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