METHOD AND DEVICES FOR THE DETERMINATION OF COLORS AND COLOR TOLERANCES IN A VISUAL MANNER IN ANY KIND OF ARTIFICIAL LIGHT OR SUNLIGHT

• US 3,653,771 A
• Filed: 10/29/1969
• Issued: 04/04/1972
• Est. Priority Date: 10/29/1969
• Status: Expired due to Term

• Current Assignee: Fritz Piringer
• Original Assignee: Fritz Piringer
• Inventors: Piringer, Fritz
• Primary Examiner(s): Wibert, Ronald L.
• Assistant Examiner(s): Rothenberg, J.
• Application Number:
  US04/872,427
• Time in Patent Office: 888 Days
• Field of Search: 356/173,174,178,191,194,195 35/28.3 88/1MI,1P,14C,14CB,14CC,14CN,14VC,14E,14R,23C,73,74,84,85,112
• US Class Current: 356/422
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/463 Colour matching
• CPC Class Codes: G01J 3/528 using colour harmony theory

Abstract

Color evaluation of a color sample is effected by producing in a simultaneous field of vision a plurality of separate color comparison regions each differing in color slightly from one another and juxtaposed with a multiplicity of images of a single small area of a color sample. The color of the sample images can be compared simultaneously with the colors of the comparison regions and a color attribute of the comparison regions varied until visual correspondence is obtained between the sample color and one of the comparison regions.

Claims

1. A visual method of performing color evaluation of a color sample, said method comprising producing, in a plane spaced from a color sample, multiple virtual images of a single small area of said color sample, composing said images in said plane in juxtaposition with a plurality of individual separate color comparison places which differ slightly in color from one another, one for each sample image, forming in said plane a simultaneous field of vision in which appear said images and said color comparison places such that the color of the sample can be compared with the colors of the color comparison places, the colors of the color comparison places being obtained by the selective combination of the three color attributes thereof such that the colors of the color comparison places differ only slightly from one another, and visually comparing the color of the sample images with that of said color comparison places and simultaneously varying the color of the latter by selectively varying at least one of the color attributes thereof to achieve visual correspondence of said sample color with one of said places.

2. A visual method of performing color evaluation of a color sample, said method comprising producing in a plane a plurality of separate color comparison regions by selectively combining the three color attributes of the colors in the comparison regions such that said colors of the comparison regions differ only slightly from one another, producing images of a small area of a color sample and distributing the images of said sample area in juxtaposition with each comparison region in said plane whereby there is produced in said plane a simultaneous field of vision in which the color of the sample can be visually compared with that of said comparison regions, and simultaneously varying at least one of the color attributes of the colors of the comparison regions to establish visual correspondence of the sample with one of said comparison regions.

3. A method as claimed in claim 2, wherein said comparison regions are arranged in said field of vision with a central region and a plurality in surrounding regions, the visual correspondence of the color of the sample being made with the color of the central region while simultaneously the colors of the surrounding regions can be compared with the color of the sample to view the magnitude of the color contrast therebetween.

4. Apparatus for enabling color evaluation of a color sample, said apparatus comprising first means for producing a plurality of separate color comparison images each differing in color slightly from one another and for distributing the color comparison images into a plane wherein said images form color comparison regions, and second means for producing a multiplicity of images of a single small area of a color sample, and for applying such images in juxtaposition with said color comparison regions in said plane to form in said plane a simultaneous field of vision of said sample images and said color comparison regions, such that the cOlor of the sample can be compared simultaneously with all the colors of said color comparison regions.

5. Apparatus as claimed in claim 4, wherein said first means for producing the separate color comparison regions comprises means for combining the three color attributes of the color at each of said color comparison regions, and means for simultaneously varying at least one of said color attributes for all of said regions.

6. A device for visually determining color and color tolerances of a sample in natural and artificial light, said device comprising an eyepiece having a field of vision, a light deflecting element, an element with a reflective multiple discontinuous surface between said light deflecting element and the field of vision, said light deflecting element and multiple discontinuous surface being operatively associated with a color sample to produce in said field of vision a plurality of images of a small area of said color sample, and means for producing a plurality of color comparison images which differ only slightly in color from one another, the latter said means being operatively positioned relative to said discontinuous surface such that said color comparison images are passed from said multiple discontinuous surface into said field of vision in juxtaposition with the sample images.

7. A device as claimed in claim 6 comprising a holder for said color sample, and means for controlling the amount of light which strikes the sample.

8. A device as claimed in claim 6 comprising means in the path of a light source for selectively controlling illumination of said sample and of the means which produces the color comparison images.

9. A device as claimed in claim 8, wherein said means for controlling illumination comprises a fixed diaphragm plate and a plurality of movable diaphragm plates disposed between the source of light and said eyepiece, said diaphragm plates having transparent and opaque areas arranged in such manner that movement of the movable diaphragm plates causes the opaque areas of such plates to eclipse alternately and in varying degrees the transparent areas of the fixed diaphragm plate, said transparent areas of the fixed diaphragm plate serving for the illumination of the sample and the means which produces the color comparison images.

10. A device as claimed in claim 9, wherein said means for producing the color comparison images comprises a first chromatic test color surface, and a neutral-gray test color surface, and light deviating units, one for each test color surface, operatively arranged with a respective transparent area of the fixed diaphragm plate for illuminating the test color surfaces with the light passing through said transparent areas, and means for superimposing light reflected from said test color surfaces to produce the color comparison images.

11. A device as claimed in claim 6, wherein said light deflecting element has a plurality of inclined surfaces in side-by-side relation to produce the plurality of separate images of said small area of the color sample, said multiple discontinuous surface having openings for the passage of said sample images to the field of vision.

12. A device as claimed in claim 10 further comprising a second neutral-gray test color surface and means for superimposing light reflected from said second neutral-gray test color surface onto each said sample image, and a further light deviating unit for illuminating the second neutral-gray test color surface.

13. A device as claimed in claim 10, wherein said means for producing the color comparison images further comprises a second chromatic test color surface, and an associated light deviating unit, and optical light mixing means for mixing color images produced by the two said chromatic test color surfaces.

14. A device as claimed in claim 9, wherein the movable diaphragm plates are provided with scales which are in fixed relation with said opaque areas thereof.

15. A device as claimed in claim 14, wherein said scales are fixedLy attached to said movable diaphragm plates, and wherein said scales and said opaque areas are integrally formed of a single layer each.

16. A device as claimed in claim 15, wherein said single layer is metal foil.

17. A device as claimed in claim 9, wherein the opaque areas of the movable diaphragm plates are so shaped as to permit said alternate eclipsing, whereby optical switching is effected by mixing white and/or black in the path of light rays of the test colors and alternately in the path of light rays of the sample.

18. A device as claimed in claim 6, wherein the element with the multiple discontinuous surface is inclined with respect to light rays reflected from the sample, said element being provided with openings which are tapered.

19. A device as claimed in claim 6, wherein said multiple discontinuous surface comprises mirror portions for reflecting the light rays from said sample and opaque portions corresponding to the desired shape of the sample images.

20. A device as claimed in claim 6, wherein said element with the multiple discontinuous surface comprises a photometer prism with a reflecting surface which is selectively discontinued and a second prism with intact surfaces, and two inversely shaped masks, respectively corresponding to the desired shape of the color comparison regions and the sample images.

21. A device as claimed in claim 6, wherein said element with the multiple discontinuous surface comprises an arrangement of one set of glass plates and two inversely shaped masks, respectively corresponding to the desired shape of the color comparison images and the sample images and arranged between the eyepiece and the means for producing the color comparison images and the sample.

22. A device as claimed in claim 6, wherein said element with the multiple discontinuous surface comprises a metal piece in combination with a tapered central reflector which is mounted on a transparent plate-shaped body, the transparent body being mounted on a block which also carries the metal piece.

23. A device as claimed in claim 22, wherein the metal piece tapers in a manner similar to the central reflector and is integral with the block.

24. A device as claimed in claim 10, wherein said chromatic test color surface is provided with parallel bands of different hues, said neutral-gray test color surface being provided with parallel bands having varying degrees of whiteness, said surfaces being oriented such that the bands thereof extend perpendicular to one another.

25. A device as claimed in claim 11, wherein said light deflecting element is a one-piece body having refractive properties.

26. A device as claimed in claim 11, wherein said light deflecting element has mirrored reflecting surfaces.