US 7,457,012 B2 · Detecting the alignment of a document in an automatic document feeder

Abstract

A method of detecting the alignment of a document in an automatic document feeder including an optical scanner that has an automatic document feeder and a document. The automatic document feeder has a colored pattern layer corresponding to a scanning window of the optical scanner. The document has at least one side edge. When the document is being fed into the automatic document feeder, the side edge is just positioned between the scanning window and the colored pattern layer. When the automatic document feeder is switched on to feed in the document, a first image retrieval is made from the document placed on the scanning window. After the document is fed in by an appropriate length, a second image retrieval is made from the document placed on the scanning window. A slant value is calculated.

Claims55

Dependent claims

A method for detecting an alignment of a document having a side edge in an automatic document feeder, the automatic document feeder included in an optical scanner having a scanning window, the method comprising:

actuating the automatic document feeder to feed in the document to a first position, wherein a portion of the side edge of the document in the first position is defined by the scanning window and a colored pattern layer in the scanning window;
capturing a first image of the document while the document is in said first position;
feeding the document a feeding length that is less than a total length of the document to a second position;
capturing a second image of the document while said document is in said second position;
and
calculating a slant value by comparing the first image with the second image.

3 more elements

Dependencies are inferred from the claim text.

Detecting the alignment of a document in an automatic document feeder

Life of this patent

Detecting the alignment of a document in an automatic document feeder

Life of this patent

Abstract

Claims55