Early transparency detection routine for inkjet printing

• US 20050073544A1
• Filed: 09/04/2003
• Published: 04/07/2005
• Est. Priority Date: 06/30/1997
• Status: Active Grant

• Current Assignee: Steven H. Walker, Stuart A. Scofield
• Original Assignee: Steven H. Walker, Stuart A. Scofield
• Inventors: Scofield, Stuart A., Walker, Steven H.
• Granted Patent: US 6,994,432 B2
• Time in Patent Office: Days
• US Class Current: 347/16
• CPC Class Codes: B41J 11/009 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 Class Codes: B41J 11/46 by marks or formations on the paper being fed
• CPC Class Codes: B41J 13/0054 Handling sheets of differing lengths
• CPC Class Codes: B41J 19/205 Position or speed detectors therefor
• CPC Class Codes: B41J 2/125 Sensors, e.g. deflection sensors nozzle clogging detection for cleaning reasons B41J2/16579; detection for compensation for failed nozzles B41J2/2139
• CPC Class Codes: B41J 2/2135 Alignment of dots
• CPC Class Codes: B41J 29/393 Devices for controlling or analysing the entire machine ; Controlling or analysing mechanical parameters involving printing of test patterns

Abstract

A system of classifying incoming media entering an inkjet printing mechanism identifies transparency media without requiring any special manufacturer markings. The media is first optically scanned using a blue-violet light at an initial intensity to obtain both diffuse and specular reflectance data. If useable, the data is compared with known values to classify the media so an optimum print mode tailored for the particular media is used. The early transparency detection system avoids time-consuming further steps trying to classify the media as photo media, plain paper, and the like, and facilitates fast printing of transparencies, which can be critical in the business environment when making last minute changes for a presentation. A printing mechanism constructed to implement this method is also provided.

Claims

1. A method of classifying incoming media entering a printing mechanism, comprising the steps of:

advancing the incoming media to a selected location;

optically scanning said media at the selected location;

collecting raw specular data and raw diffuse data while scanning;

averaging said raw specular data and raw diffuse data;

determining whether the averaged specular data is greater than the averaged diffuse data;

when the averaged specular data is greater than the averaged diffuse data, identifying the media as a transparency; and

2. A method according to claim 1 wherein when the averaged specular data is not greater than the averaged diffuse data, performing Fourier transforms on the raw specular data and raw diffuse data and analyzing the results thereof to determine the type of incoming media.

3. A method according to claim 1 wherein:

the incoming media includes a header area which may be provided with an opaque header; and

the advancing comprises advancing a leading edge of the media such that the header area is not at said selected location during said step of optically scanning.

4. A method according to claim 1 further including locating side edges of the media through further optical scanning of the media.

5. A method according to claim 4 further including using specular data to locate the media edges.

6. A method according to claim 5 further including finding a low-to-high transition in the specular data to locate the media edges.

25. The method of claim 1, particularly for use with such printing mechanism which has, visible-light line sensor that is used for mechanical alignments in the mechanism or for color measurements, or both;

and wherein;

the scanning step comprises passing the, visible-light line sensor over said media while performing the collecting step; and

the collecting step comprises producing said data as a function of position of the sensor along a path over the media.

7-24. -24. (canceled)

26. A method of classifying incoming paper, transparency stock, or other printing media entering a printing mechanism which has a visible-light line sensor that is used for mechanical alignments in the mechanism or for color measurements, or both, said method comprising the steps of:

advancing the incoming media to a selected location;

optically scanning the visible-light line sensor over said media at the selected location;

collecting raw specular data and raw diffuse data while scanning;

averaging said raw specular data and raw diffuse data;

determining whether the averaged specular data is greater than the averaged diffuse data; and

when the averaged specular data is greater than the averaged diffuse data, identifying the media as a transparency.

27. The method of claim 26, wherein:

the collecting step comprises generating successive data as a function of position of the sensor along a path over the media.

28. A method of classifying incoming media entering a printing mechanism, wherein the incoming media may or may not have an opaque header along a leading edge thereof;

said method comprising the steps of;

advancing the incoming media to a selected location;

optically scanning said media at the selected location;

collecting raw specular data and raw diffuse data while scanning;

averaging said raw specular data and raw diffuse data;

determining whether the averaged specular data is greater than the averaged diffuse data;

when the averaged specular data is greater than the averaged diffuse data, identifying the media as a transparency; and

the advancing step comprises advancing the leading edge until any header is not involved in said optically scanning.

29. A method of classifying incoming media entering a printing mechanism, comprising the steps of:

advancing the incoming media to a selected location;

optically scanning said media at the selected location;

collecting raw specular data and raw diffuse data while scanning;

averaging said raw specular data and raw diffuse data;

determining whether the averaged specular data is greater than the averaged diffuse data;

when the averaged specular data is greater than the averaged diffuse data, identifying the media as a transparency; and

locating side of edges of the media through further optical scanning of the media, for determination of media width.

30. A method of classifying incoming media entering a printing mechanism, comprising the steps of:

advancing the incoming media to a selected location;

optically scanning said media at the selected location;

collecting raw specular data and raw diffuse data while scanning;

averaging said raw specular data and raw diffuse data;

determining whether the averaged specular data is greater than the averaged diffuse data;

when the averaged specular data is greater than the averaged diffuse data, identifying the media as a transparency; and

locating side edges of the media through further optical scanning of the media, using specular data to locate the media edges.