Edge detector

Patent metadata

Field	Value
Publication number	US-9662909-B2
Application number	US-201315030264-A
Country	US
Kind code	B2
Filing date	Oct 23, 2013
Priority date	Oct 23, 2013
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

A detector device is disclosed for detecting an edge of a medium in a media processing system, the detector device comprising a spectrophotometer and a processing unit, the spectrophotometer scanning a medium in a media processing area and generating an output tuple, the processing unit comparing the output tuple to at least one reference tuple for detecting an edge of a medium. A printing system and method of detecting an edge of a medium in a media processing system are also disclosed.

First claim

What is claimed is:

1. A detector device for detecting an edge of a medium in a media processing system, the detector device comprising:
a spectrophotometer to scan a medium in a media processing area and generate an output tuple; and
a processing unit to compare the output tuple to a reference tuple for detecting an edge of a medium.

2. The detector device of claim 1 , wherein the spectrophotometer generates an output tuple in the LAB color space, including a lightness value L and two color components a, b.

3. The detector device of claim 1 , wherein the processing unit accesses a look-up table including the reference tuple for:
the spectrophotometer scanning an empty platen;
the spectrophotometer scanning a white medium;
the spectrophotometer scanning a medium;
the spectrophotometer scanning a transparent medium; or
the spectrophotometer scanning a partly transparent medium.

4. The detector device of claim 1 , wherein the spectrophotometer is mounted on a carriage that moves over the media processing area.

5. A printing system comprising:
a loading unit for loading a print medium into the printing system;
a media advance unit for transporting the print medium into and through a printing zone; and
a monitoring unit for monitoring a printing result, the monitoring unit to:
detect, based on a comparison of sensor data to a reference tuple,

an edge of the print medium or skewness of the print medium or both.

6. The printing system of claim 5 , wherein the monitoring unit comprises a spectrophotometer.

7. The printing system of claim 6 , wherein:
the spectrophotometer scans the printing zone and generates an output tuple; and
the monitoring unit detects an edge of the print medium by comparing the output tuple of the spectrophotometer to the reference tuple.

8. The printing system of claim 7 , wherein the monitoring unit accesses a set of reference tuples to determine whether the print medium is opaque, transparent or porous.

9. The printing system of claim 8 , further comprising:
a movable line sensor; or
a stationary media advance sensor device,
wherein the monitoring unit processes an output of the line sensor or the media advance sensor device for determining whether a print medium is transparent or porous.

10. A method of detecting an edge of a medium in a media processing system, the method comprising:
scanning a medium in a media processing area by a spectrophotometer;
generating an output tuple;
comparing the output tuple to a reference tuple for detecting an edge of the medium.

11. The method of claim 10 , further comprising:
gathering a plurality of output tuples from the spectrophotometer while the spectrophotometer scans the media processing area; and
processing the plurality of output tuples by repeatedly comparing each respective output tuple or a mean value of a number of output tuples or both to a respective reference tuple to determine a side edge of the medium.

12. The method of claim 11 , further comprising:
after having determined the side edge of the medium, generating a plurality of output tuples while scanning the medium and while the medium moves through the media processing area; and
processing the plurality of output tuples by comparing each respective output tuple or a mean value of a number of output tuples or both to a respective reference tuple to determine a leading edge of the medium.

13. The method of claim 10 , further comprising:
scanning the medium by a spectrophotometer at least twice and generating at least two respective output tuples; and
evaluating the at least two output tuples to detect a leading edge of the medium when there is a significant change between the output tuples generated in subsequent scans.

14. The method of claim 10 , further comprising:
detecting the presence of a porous medium as a function of significant changes of tuple values within one scan or between subsequent scans of the spectrophotometer.

15. The method of claim 10 , comprising:
generating, via the spectrophotometer, a plurality of output tuples while scanning the medium in the media processing area; and
processing the plurality of output tuples by comparing output tuples with each other wherein an output tuple of the plurality of output tuples is used as a reference tuple for other output tuples of the plurality of output tuples.

Assignees

• Hewlett Packard Development Co Lp

Inventors

• Gracia Verdugo Antonio
• Uroz Soria Juan
• Borrell Avila Oriol

Classifications

• B41J11/009

  Detecting type of paper, e.g. by automatic reading of a code that is printed on a paper package or on a paper roll or by sensing the grade of translucency of the paper · CPC title

• B41J11/0095 Primary

  Detecting means for copy material, e.g. for detecting or sensing presence of copy material or its leading or trailing end · CPC title

• G01B11/24

  for measuring contours or curvatures · CPC title