Back-branding media determination system for inkjet printing

• US 6,585,341 B1
• Filed: 08/30/2000
• Issued: 07/01/2003
• Est. Priority Date: 06/30/1997
• Status: Expired due to Fees

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: Scofield, Stuart A., Walker, Steven H.
• Primary Examiner(s): Gordon, Raquel Yvette
• Assistant Examiner(s): Huffman, Julian D.
• Application Number:
  US09/651,769
• Time in Patent Office: 1,035 Days
• Field of Search: 347/14, 347/16, 347/105, 347/19, 400/282, 399/45, 399/389, 382/317, 250/559.01, 250/559.04, 250/559.44, 250/555
• US Class Current: 347/14
• 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 the type of incoming media entering an inkjet or other printing mechanism is provided to identify the media according to markings or identifying indicia on the back surface of the media opposite the printing surface which ultimately bears the printed image. The printing surface of the incoming media is optically scanned using a blue-violet light to obtain both diffuse and specular reflectance values. A spatial frequency signature for the incoming media is compared with known values for different types of media to classify the media according to major categories (transparencies, glossy photo media, premium or plain paper), and specific types of media within these categories (matte photo, premium, or high-gloss photo media). An optimum print mode is selected according to the determined media type to automatically generate outstanding images without bothersome user intervention. A printing mechanism constructed to implement this method is also provided.

Claims

1. A method of classifying incoming media entering a printing mechanism, with the media having a printing surface and an opposing back surface which bears an identifying indicia located at a specific position for all said different types of media bearing identifying indicia, comprising the steps of:

optically scanning the printing surface of the incoming media only at said specific position;

gathering information about the identifying indicia during the optically scanning step; and

analyzing the gathered information through comparison with known values for different types of media bearing identifying indicia to classify the incoming media as one of said different types.

2. A method according to claim 1 further including the step of, following the analyzing step, printing a selected image on the printing surface of the incoming media.

3. A method according to claim 2 further including the step of, between the analyzing step and the printing step, selecting a print mode optimized for the printing step, wherein the print mode is optimized for the incoming media type classified in the analyzing step.

4. A method according to claim 1 wherein:

said identifying indicia comprises a bar code;

the optically scanning step comprises optically scanning the bar code; and

the analyzing step comprises the step of comparing the scanned bar code with known bar code values for said different types of media.

5. A method according to claim 1 wherein:

said identifying indicia comprises a logo;

the optically scanning step comprises optically scanning the logo; and

the analyzing step comprises the step of comparing the scanned logo with known logos for said different types of media.

6. A method according to claim 1 wherein:

said identifying indicia comprises a repeating pattern;

the optically scanning step comprises optically scanning the repeating pattern; and

the analyzing step comprises the step of comparing the scanned repeating pattern with known patterns for said different types of media.

7. A method according to claim 1 wherein:

said identifying indicia comprises text;

the optically scanning step comprises optically scanning said text; and

the analyzing step comprises the step of comparing the scanned text with known text for said different types of media.

8. A method according to claim 1 wherein:

said identifying indicia comprises a watermark;

the optically scanning step comprises optically scanning the watermark; and

the analyzing step comprises the step of comparing the scanned watermark with known watermarks for said different types of media.

9. A method according to claim 1 wherein:

the incoming media has a first region of a first density;

said identifying indicia comprises a second region of a second density different from the first density;

the optically scanning step comprises optically scanning said second region; and

the analyzing step comprises the step of comparing the scanned second region with known values for said different types of media.

10. A method according to claim 9 wherein the second density is greater than the first density.

11. A method according to claim 1 wherein:

said identifying indicia comprises a reflective member;

the optically scanning step comprises optically scanning the reflective member; and

the analyzing step comprises the step of comparing the scanned reflective member with known values for said different types of media.

12. A method according to claim 11 wherein the reflective member comprises a coating applied to the back surface of the media.

13. A method according to claim 11 wherein the reflective member is adhered to the back surface of the media.

14. A method of classifying incoming media entering a printing mechanism, with the media having a printing surface and an opposing back surface which bears an identifying indicia, comprising the steps of:

optically scanning the printing surface of the incoming media;

gathering information about the identifying indicia during the optically scanning step; and

analyzing the gathered information through comparison with known values for different types of media bearing identifying indicia to classify the incoming media as one of said different types,

wherein the identifying indicia are located at differing positions each corresponding to one of said different types of media bearing identifying indicia;

the optically scanning step comprises only optically scanning the incoming media until said identifying indicia is encountered; and

the gathering step comprises gathering information as to which of said differing positions said identifying indicia was encountered during the optically scanning step.

15. An inkjet printing mechanism which prints on incoming media having a printing surface and an opposing back surface which bears an identifying indicia, comprising:

a frame;

a media sensor supported by the frame to monitor the printing surface of the incoming media, with the media sensor including an illuminating element which illuminates the incoming media, and a sensor which receives light reflected from the illuminated media and in response thereto, generates a reflectance signal, with light emitted by the illuminating element penetrating through the media to illuminate the identifying indicia on the opposing back surface for reading by the sensor; and

a controller which compares the reflectance signal with known values for different types of media bearing identifying indicia to select a print mode corresponding to the incoming media.

16. An inkjet printing mechanism according to claim 15 further including a carriage which traverses across the incoming media, with the carriage supporting the media sensor to scan across the incoming media.

17. An inkjet printing mechanism according to claim 15 wherein the sensor comprises:

a diffuse sensor which receives diffuse light reflected from the illuminated media and generates a diffuse signal portion of the reflectance signal, with the diffuse signal portion having an amplitude proportional to the diffuse reflectance of the media; and

a specular sensor which receives specular light reflected from the illuminated media and generates a specular signal portion of the reflectance signal, with the specular signal portion having an amplitude proportional to the specular reflectance of the media.

18. An inkjet printing mechanism according to claim 17 further including:

a diffuse field stop which limits the light received by the diffuse sensor; and

a specular field stop which limits the light received by the specular sensor.

19. An inkjet printing mechanism according to claim 15 wherein the illuminating element emits a blue-violet light having a peak wavelength selected from a range of 400-430 nanometers.