.~ With color determination by light intensity comparison
DEFINITION
Classification: 356/425
With color determination by light intensity comparison:
(under subclass 402) Subject matter wherein the color comparison of two masses is made by comparing the intensity of the light from the two masses (either transmitted or reflected).
(1) Note. This type of comparison has been designated in the literature as heterochromatic photometry. It is usually restricted to comparing different shades or tints of the same color. Usually filters are not used in color determination of this type.
(2) Note. Subclasses 432+ and 445+ provide for the reflection and transmissive testing of materials by noting the intensity of the reflected or transmitted light. The distinction between subclass 425 and subclasses 432+ and 445+ is that the articles examined in subclass 425 are of the same color and differ only in tint or shade from one another, while subclasses 432+ and 445+ have no color involved at all.
(3) Note. Where a liquid is tested for concentration of a solute in a solvent and the comparison is made with a light intensity source and where no color is involved at all and where the liquid is claimed, the original patent is placed under the appropriate subclasses of 409+ and is cross-referenced in 422.
(4) Note. Where a plurality of reflective colored standards are claimed in the comparison of a gaseous or solid colored substance and the comparison is noted visually or photoelectrically without the inclusion of filters, the original is classified under subclass 421 and cross-referenced in subclass 425.
SEE OR SEARCH THIS CLASS, SUBCLASS:
409+, for analyzing chemical solutions by comparing colors on the basis of intensity alone. See (3) Note above.
SEE OR SEARCH CLASS 209, Classifying, Separating, and Assorting Solids, particularly
581, where articles are physically separated on the basis of color by using only a light intensity test.
250, Radiant Energy,
214, for circuits responsive to photosensitive devices which do not claim a support for articles examined for color by a
light intensity test or do not claim an indicator.
362, Illumination,
251+, for light projectors which include a source of illumination together with means to modify the direction of the light from the source and structure to house the light arrangement.
