Grouped Light Source Color Locus Control via Segmentation
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Solution Overview
Problem
Light sources emitting mixed-colored light, such as those used for backlighting displays, experience fluctuations in color locus due to aging or external factors like temperature changes, making it difficult to maintain a constant color output.
Innovation Solution
Dividing primary light sources into groups allows for separate control of brightness values within predetermined ranges, enabling simple control of the color locus by using pulse-width-modulated signals and sensors to determine and adjust brightness values, thereby reducing control complexity and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the brightness values of all primary light sources are controlled individually to maintain constant color locus, then the color stability is improved, but the control complexity increases significantly
Solution Approach 1:
The patent divides the plurality of primary light sources into multiple groups based on their dominant wavelengths. Each group contains light sources of the same color (e.g., red, green, blue). By controlling each group collectively rather than individual light sources, the control complexity is reduced while maintaining color locus stability. The brightness values of light sources within each group are determined and controlled separately according to colors, which resolves the contradiction between individual control precision and system complexity.
2Device complexity
If primary light sources are selected with respect to one another to have brightness values within a predetermined range, then the color locus control is simplified, but the selection requirements and costs increase
Solution Approach 1:
The patent applies local quality by selecting primary light sources within each group to have brightness values within a predetermined range (e.g., between 24000 mlm and 61000 mlm). This local selection criterion ensures that light sources within the same color group have comparable brightness characteristics, which simplifies the control of color locus. The predetermined range acts as a local quality constraint that balances manufacturing feasibility with control simplicity.
3Illumination intensity
If a large number of primary light sources are used to achieve desired brightness, then the illumination intensity is improved, but the number of sources requiring selection and control increases
Solution Approach 1:
The patent merges the control of multiple primary light sources by grouping them according to their colors. Instead of controlling each individual light source, the brightness values of light sources within each color group are controlled collectively. This merging approach maintains the total illumination intensity provided by a large number of light sources while reducing the control complexity to the level of color groups rather than individual sources.
Data Source
AI summary
A light source (10) is disclosed, emitting multi-colored light with light of at least two different colors, emitted from a number of primary light sources (1) wherein the primary light sources (1) are divided into groups and the brightness values of the primary light sources (1) within a group are determined and controlled separately according to color, such that the color location of the multi-colored light lies in a given region of the CIE standard color diagram. The invention further relates to a method for controlling such a light source (10) and an illumination device with such a light source (10), for example, for backlighting a display.