Selective Face Lighting for Daylight Contrast Reduction
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Solution Overview
Problem
Existing daylight-responsive lighting systems and therapeutic lighting systems face challenges such as high contrast between natural daylight and human subjects, making it difficult to view facial expressions, and require dedicated spaces for effective use, which can be bothersome to others.
Innovation Solution
The development of lighting systems with independently adjustable face and task lighting, where face lighting is selectively applied to user segments with human presence, allowing for different modes and adjustable intensity, spectral composition, and direction, to minimize contrast and provide targeted illumination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If lighting fixtures are dimmed in response to entering daylight, then energy is saved and a more pleasing environment is provided, but contrast between the bright window and objects positioned in front of the window becomes too high, making viewing difficult
Solution Approach 1:
The lighting system divides illumination into separate functional components: task lighting for work surfaces and face lighting for human subjects. This segmentation allows independent control of each lighting type, enabling the system to maintain appropriate illumination levels for faces even when overall ambient lighting is reduced due to daylight conditions, thereby resolving the contrast problem while preserving energy savings.
Solution Approach 2:
The system applies different lighting qualities to different spatial zones - task lighting provides functional illumination for work areas while face lighting provides targeted illumination for human subjects. This local differentiation ensures that faces receive sufficient illumination to reduce contrast with bright windows, while the overall system can still be dimmed to save energy during daytime hours.
2Reliability
If therapeutic lighting systems provide bright light for therapy, then light therapy effectiveness is improved, but the bright light becomes bothersome to other individuals present that do not need the light therapy
Solution Approach 1:
The system segments the user population into different groups - individuals receiving light therapy and those who are not. Face lighting is selectively applied only to user segments with detected human presence, allowing therapeutic lighting to be provided to specific individuals without bothering others in the same environment.
Solution Approach 2:
The system uses sensors as intermediaries to detect human presence and determine which user segments require face lighting. This intermediary detection mechanism enables selective application of bright therapeutic light only to those who need it, while leaving other areas at normal ambient levels, thus resolving the conflict between therapy effectiveness and avoiding disturbance to others.
3Illumination intensity
If face lighting is provided to all user segments, then viewing of facial expressions is improved, but energy consumption increases
Solution Approach 1:
Instead of providing face lighting to all user segments uniformly, the system applies partial action by selectively providing illumination only to user segments where human presence is detected. This selective application reduces overall energy consumption while maintaining sufficient facial illumination where needed, resolving the contradiction between viewing quality and energy efficiency.
Data Source
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AI summary
Disclosed are methods and apparatus that enable selectively applied face lighting and, optionally, selectively applied task lighting, for example, in daylight-responsive lighting systems and/or therapeutic lighting systems. The face lighting may be selectively provided in a plurality of modes to one or more user segments, and, optionally, only provided to those user segments having a human presence.