1. Field of the Invention
The invention pertains to a method and apparatus for displaying light representative of a standard color adjacent a sample, and more particularly to a method and apparatus for displaying light reflected from a standard color adjacent a microscopic sample whereby the color of the sample may be directly compared with the color of the standard color in the field of view of a microscope.
2. Description of the Prior Art
For various reasons, it is often necessary to determine the precise color of a particular sample. This is particularly true of samples being subjected to microscopic examination to classify the sample's origin, composition or background. For example, in the field of palynology, the thermal maturation of spores and pollen that have been preserved in rock formations can be determined by classifying their color. Spores and pollen from relatively young formations are immature and appear to be a light greenish yellow. Spores and pollen from relatively old formations are mature and appear black. Spores and pollen from formations of intermediate age and maturities range in color from yellow through orange to brown. The color of the spores and pollen can be correlated with the thermal history of the formation to give valuable information relating to the potential for producing hydrocarbons from the formation. In analyzing such samples it is critical to distinguish between close shades of colors in order to properly classify the spore or pollen samples as to the degree of thermal maturation.
Color determination of microscopic samples has commonly been accomplished by microscopic examination of the samples and then subjectively comparing the samples with standard colors on a color chart. Since this process has commonly required the operator to examine the sample in the microscope and then take his eyes away to match the color of the sample with a color on a color chart, a high degree of subjectivity in color determination can result and lead to varying classification, even when the classification is done by the same operator under substantially uniform viewing conditions. The same problem is also present, although somewhat less acute, when non-microscopic samples are visually compared with a color standard to determine the standard color of the sample. Color determination can also be made by spectral examination of light reflected from a sample. Such processes, however, commonly require a relatively large investment in equipment and may be cumbersome in operation.