US 2017/0254770 A1 · IDENTIFICATION OF PAPER MEDIA USING IMPEDANCE ANALYSIS

Abstract

A microcontroller-based system for identifying a paper type of a sample of paper from a measurement of its electrical impedance. An interdigital dielectric sensor (55) is deployed in the paper path of a printer (PTR), and the electrical impedance at the sensor, as affected by a sheet of paper (P) near the sensor, is measured over a plurality of frequencies of a stimulus signal. The stimulus signal may be sinusoidal or a square wave. The impedance characteristic, in magnitude or phase, or both, is compared against a plurality of reference impedance characteristics, each associated with a paper type, to identify the closest match and thus the type of paper of the sample sheet.

Claims18

Dependent claims

A system for identifying a paper type of a paper sample at a printer, comprising:

a memory resource, storing a plurality of reference impedance characteristics, each corresponding to a paper type;
a capacitive sensor, deployed near the paper sample;
stimulus generator circuitry, coupled to the sensor, for generating a stimulus signal at each of a plurality of fundamental frequencies;
an analog-to-digital converter, coupled to the sensor, for sampling a response signal from the sensor to the stimulus signal;
and
processing logic, coupled to the analog-to-digital converter, for processing the sampled response signal for each of the plurality of fundamental frequencies, to determine a sample impedance characteristic for the paper sample, and for comparing the sample impedance characteristic with each of the plurality of reference impedance characteristics to identify the paper type of the paper sample.

3 more elements

Dependencies are inferred from the claim text.

Identification of paper media using impedance analysis

Life of this patent

Identification of paper media using impedance analysis

Life of this patent

Abstract

Claims18