Dichroic Filters and Additive Color Displays
Edward F. Rizy · Information Display · 1966
Abstract Large‐scale displays for Air Force Command and Control systems commonly color‐code displayed data. A repertory of seven codes is available through the technique of color addition, where dichroic filters split the white source into three primary colors, which are mixed on the screen to form colormixture codes as well. The author investigated the effect of dichroic filters of different reflectances upon observer performance on the seven color codes. The object of the study was to define performance parameters on filters, a preliminary step to setting filter specifications. Statistically significant differences between filters and between color codes were detected and analyzed. In the dichroic filter arrangement adopted, blue‐red filter order, a blue filter reflecting wavelengths well into the green region facilitated performance in the majority of the color codes. A red filter close to the infrared in reflectance reduced performance in most codes. The most efficient color code, regardless of what filters were used, was red. Green, blue and cyan were the least efficient. Recommendations were made regarding options that would most likely lead to satisfactory seven‐color coding for additive displays.