US 5,844,698 A · Document scanner without pressure actuated mechanical document sensor and document scanning method thereof

Abstract

A document scanner includes a roller to drive the document along a forward path, an image sensor arranged adjacent to the roller to scan the image on the document, and a control unit instructing the operations of the roller and the image sensor. The roller has an outer surface extending in an axial direction on which a plurality of interleaved black and white sections are arranged in a predetermined pattern and having a predetermined axial length. There is also provided a document scanning method associated with the structure of the document scanner, including the steps of (a) actuating the image sensor to perform the sensing operation toward the gray level pattern, storing the gray level value obtained from the sensing operation as the REFERENCE value; (b) actuating the image sensor to periodically perform the sensing operation toward the image viewed by the image sensor so as to obtain the CURRENT value; (c) initiating the scanning operation of the image sensor and the rolling movement of the roller when the CURRENT value and the REFERENCE value are substantially different; terminating the scanning operation of the image sensor and the rolling movement of the roller when the CURRENT value and the REFERENCE value are substantially the same.

Claims15

Dependent claims

A media scanning apparatus for performing scan operation of an image on the media, comprising:

a roller with a gray level pattern formed on an outer surface of the roller, the roller being rotatable to feed in the media, when the media is being fed in, the media overlaying the gray level pattern;
an image sensor located adjacent to the roller, the image sensor having a field of view directed toward the roller and periodically generating an electrical signal representative of a image viewed by the image sensor;
and
a control unit, coupled to the image sensor, for selectively initiates and terminates scan operation of the image, the control unit generating and storing a REFERENCE value as the gray level pattern is viewed by the image sensor, the control unit periodically generating a CURRENT value in response to the electrical signal, wherein the control unit initiates scan operation of the image when the CURRENT value generated is substantially different from the REFERENCE value.

1 more element

Dependencies are inferred from the claim text.

Document scanner without pressure actuated mechanical document sensor and document scanning method thereof

Life of this patent

Document scanner without pressure actuated mechanical document sensor and document scanning method thereof

Life of this patent

Abstract

Claims15