Claims
- 1. A color correction system for a color printer having an output path for moving printed color sheets, including printed test sheets with printed color test patches, in which a spectrophotometer is mounted adjacent to said printer output path for sensing the colors printed on said printed color test patches on said printed test sheets as said printed test sheets are moving past said spectrophotometer in said output path, said color correction system including plural illumination sources for sequentially illuminating said color test patches with different illumination spectra in a substantially circular illumination pattern, and a plural photodetectors system for providing electrical output signals in response to the color of said test patches from said sequential illumination of said test patches by reflection of said illumination of said color test patches in said substantially circular illumination pattern by said illumination sources, and a lens system for transmitting said reflected illumination from said color test patches to said plural photodetectors system, so as to provide improved angular displacement insensitivity of said spectrophotometer relative to said printed test sheets.
- 2. The color correction system of claim 1, wherein said plural photodetectors system comprises a plurality of photodetectors angularly spaced around said substantially circular illumination pattern to receive reflected illumination therefrom at substantially the same angle from substantially opposing directions.
- 3. The color correction system of claim 1, wherein a common central lens system is provided, and wherein said different illumination spectra from said plural illumination sources for sequentially illuminating said color test patches in a substantially circular illumination pattern are perpendicularly aimed by said central lens system at substantially the same area of said color test patches on said printed test sheets to provide said substantially circular illumination pattern thereof.
- 4. The color correction system of claim 1, wherein said plural illumination sources comprise a plurality of closely adjacent different spectral emission LEDs with a sequential actuation circuit.
- 5. A color correction system for a color printer having an output path for moving printed sheets, including printed test sheets with printed color test patches, in which a spectrophotometer is mounted adjacent to said printer output path for sensing the colors printed on said printed color test patches on said printed test sheets as said printed test sheets are moving past said spectrophotometer in said output path, said spectrophotometer being adapted to measure the colors of said printed color test patches on said printed test sheets while said moving printed test sheets are variably angularly oriented relative to said spectrophotometer, said spectrophotometer comprising plural illumination sources for sequentially projecting plural different spectral illuminations from said plural illumination sources substantially perpendicular to said printed color test patches to illuminate said color test patches, and plural photodetectors angularly spaced from said illuminated color test patches to angularly receive reflected illumination therefrom from different directions, so as to provide reduced angular displacement sensitivity of said spectrophotometer relative to said color test patches.
- 6. The color correction system of claim 5, wherein said plural illumination sources illuminate a substantially circular illumination area of said color test patches.
- 7. The color correction system of claim 5, wherein said plural photodetectors comprises an array of plural photodetectors spaced apart on at least two opposing sides of said illuminated color test patches to receive said reflected illumination therefrom illumination area at substantially the same angle but from opposing directions, so as to provide reduced angular displacement sensitivity of said spectrophotometer relative to said color test patches.
- 8. The color correction system of claim 7, wherein said plural illumination sources illuminate a substantially circular illumination area.
- 9. The color correction system of claim 5, wherein said plural illumination sources are approximately eight or less LEDs providing a correspondingly limited number of different spectral illuminations.
- 10. The color correction system of claim 5, wherein said plural illumination sources consist of less than approximately five LEDs providing a corresponding limited number of different spectral illuminations.
- 11. The color correction system of claim 5, wherein said plural photodetectors have plural photo-sites and plural different spectral responses.
- 12. The color correction system of claim 5, wherein there are three said plural photodetectors.
- 13. The color correction system of claim 5, wherein said plural photodetectors are mounted in a substantially circular pattern around and spaced from said plural illumination sources.
- 14. The color correction system of claim 5, wherein a lens system is provided for said plural photodetectors providing approximately 1:1 imaging optics for each.
- 15. A method of color correction for a color printer having an output path for moving printed sheets including printed test sheets with printed color test patches, in which a spectrophotometer is mounted adjacent to said printer output path for sensing the colors printed on said printed color test patches on said printed test sheets as said printed test sheets are moving past said spectrophotometer in said output path, said spectrophotometer being adapted to measure the colors of said printed color test patches on said printed test sheets while said moving printed test sheets are variably angularly oriented relative to said spectrophotometer to provide a broad spectrum color measurement of said color test patches, comprising substantially perpendicularly sequentially illuminating a substantially circular area of said color test patches with a limited plural number of different spectra illuminations, and sequentially non-contact measuring reflected illumination from said sequentially illuminated substantially circular area of said color test patches at approximately 45 degrees thereto with at least one photodetector spaced from said color test area to provide reduced angular sensitivity of said photodetector relative to said color test patches.
- 16. The method of claim 15, utilizing a detector array comprising plural photodetectors mounted on opposing sides of said color test patches, the outputs of which are averaged to further reduce said angular sensitivity relative to said color test patches.
- 17. The method of claim 15, wherein said at least one photodetector comprises plural photodetectors each receiving said reflected illumination through a lens system having an approximately 1:1 imaging ratio to provide relative displacement insensitivity of said photodetectors relative to said color test patches.
- 18. A method of color correction for a color printer having an output of printed sheets including printed test sheets with printed color test patches, in which a non-contacting spectrophotometer measures the colors of said printed color test patches on said printed test sheets, wherein said color test patches are substantially perpendicularly illuminated in a substantially circular illuminated area of said color test patches sequentially with a limited plural number of different spectra illuminations, and the angularly reflected illumination from said sequentially substantially circularly illuminated color test patch areas is measured by applying said angularly reflected illumination simultaneously to plural photodetectors spaced around said illuminated area and providing averaged output signals from said photodetectors for reduced variable angle positioning sensitivity of said color test patches relative to said non-contacting spectrophotometer.
- 19. A color correction system for a color printer comprising means for substantially perpendicularly sequentially illuminating a substantially circular color test area of printed test sheets with a limited plural number of different spectra illuminations, and means for sequentially measuring the angularly reflected illumination from said sequentially illuminated substantially circular illuminated color test area by applying said angularly reflected illumination simultaneously to plural photodetectors spaced around said color test area and summing the outputs of said plural photodetectors to provide an averaged output.
- 20. The color correction system for a color printer of claim 19, wherein said limited plural number of different spectra illuminations is provided by a plurality of different LEDs in a common area with a common shared lens system and a sequential LED actuation circuit.
Parent Case Info
[0001] This is a divisional of application Ser. No. 09/862,945 filed May 22, 2001 by the same inventors, and claims priority and incorporations by reference therefrom. This divisional application is being filed in response to a restriction requirement in that prior application and contains re-written and/or additional claims to the restricted subject matter.
[0002] Cross-reference and incorporation by reference is also made to the following copending and commonly assigned U.S. patent applications: U.S. application Ser. No. 09/448,987, filed Nov. 24, 1999, Attorney Docket No. D/99511Q, now U.S. Pat. No. 6,351,308, issued Feb. 26, 2002, and U.S. application Ser. No. 09/449,263, filed Nov. 24, 1999, Attorney Docket No. D/99511Q1, both by Lingappa, K. Mestha; Continuation-In-Part Application Ser. No. 09/535,007, filed Mar. 23, 2000, by the same Fred F. Hubble, III and Joel A. Kubby, Attorney Docket No. D/99511i, now U.S. Pat. No. 6,384,918 issued May 7, 2002, claiming priority from U.S. application Ser. No. 09/448,774, filed Nov. 24, 1999 Attorney Docket No. D/99511 (abandoned); and application Ser. No. 09/862,247, filed May 22, 2001, by Jagdish C. Tandon and Lingappa K. Mestha, Attorney Docket No. D/99660.
Divisions (1)
|
Number |
Date |
Country |
Parent |
09862945 |
May 2001 |
US |
Child |
10385408 |
Mar 2003 |
US |