US 6,291,829 B1 · Identification of recording medium in a printer

Abstract

The present invention is a method and device for identifying recording media in a printer. The invention utilizes fine structure of the media revealed by illumination from one or more directions to distinguish among different kinds of plain papers, coated papers, such as glossy papers, and transparency films. When the medium is bond paper, by introducing light at an angle of less than approximately sixteen degrees relative to the surface, raised surface irregularities cast shadows creating a pattern rich in detail. For glossy surfaces, a high contrast image is obtained in the specular direction from normally incident illumination. The medium surface is imaged on an optoelectronic sensor to form a characteristic vector which is compared with reference vectors, corresponding to different media types, to determine the recording medium. The detection of the recording medium may then be used to change the characteristics of the printer.

Claims29

Dependent claims

An apparatus comprising:

at least one illumination source disposed near a media path for a recording medium, light from said at least one illumination source impinging on a surface of said recording medium;
at least one sensor element positioned to receive light from said surface, generated by said at least one illumination source, so as to detect radiation intensity from an area on said surface that has a dimension smaller than 100 μm;
and
a processing device for receiving signals corresponding to outputs of said at least one sensor element, said signals being processed to identify said recording medium.

1 more element

Dependencies are inferred from the claim text.

Identification of recording medium in a printer

Life of this patent

Identification of recording medium in a printer

Life of this patent

Abstract

Claims29