Light Exit Window Cavity Layout for Lower Contrast Sensitivity

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Solution Overview

Problem

Large luminous surfaces face challenges in reducing contrast sensitivity due to their size, which complicates tooling, handling, and installation, and existing solutions like increasing surface area or dimming flux do not adequately address observation direction-dependent contrast sensitivity and scalability issues.

Innovation Solution

A light generating system with a first light generating device and a unit comprising an open and closed hollow part, where the open part is concave and diffuse reflective, and the closed part is translucent and diffuse reflective, allowing light to be diffused and controlled for reduced contrast sensitivity and scalable lighting effects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If large luminous surfaces are used to reduce contrast modulation, then the area increases, but the tooling, handling, and installation complexity increases

Engineering Contradiction:
Improveluminous surface areaVSAvoidtooling and handling complexity
Core Design Contradiction:
Area of stationary objectVSEase of manufacture

Solution Approach 1:

The light generating system is divided into multiple modular units, each comprising a light generating device and an optical cavity assembly. These units can be manufactured separately and then assembled to form large-scale luminous surfaces, thereby reducing tooling and handling complexity while maintaining large area coverage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The optical cavity is nested within the housing structure, with the light generating device positioned inside the cavity. This nested arrangement allows compact packaging and simplified handling of integrated assemblies, reducing installation complexity while maintaining large effective luminous area.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Adaptability or versatility

If traditional lighting devices are integrated into ceiling architectures, then architectural flexibility is improved, but contrast sensitivity challenges persist

Engineering Contradiction:
Improvearchitectural integration flexibilityVSAvoidcontrast sensitivity
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The optical cavity employs localized diffuse reflective properties on specific surfaces (such as the bottom and side walls) while maintaining translucency in the light exit window. This selective application of optical properties reduces contrast sensitivity at critical locations while preserving architectural integration flexibility.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The system allows dynamic adjustment of lighting parameters including intensity and color temperature of the light generating device, enabling adaptation to different observation angles and architectural configurations while maintaining optimal contrast sensitivity performance.

Inventive Principle:
Principle #15Dynamics

3Length of stationary object

If the size of luminous surfaces is downscaled to match office ceiling grids, then installation space requirements are reduced, but contrast modulation worsens to 2-4 cycles/degree

Engineering Contradiction:
Improveceiling element sizeVSAvoidcontrast modulation
Core Design Contradiction:
Length of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The optical cavity introduces a third dimension (vertical depth) to the lighting system, allowing small footprint units to achieve large effective luminous area through light diffusion and reflection within the cavity volume. This dimensional transition enables downscaling to office grid sizes while maintaining favorable contrast characteristics.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The diffuse reflective surfaces within the optical cavity act as intermediaries that scatter and redistribute light from the compact light generating device, creating a larger effective luminous area that reduces contrast modulation even when the physical unit size is downscaled for office ceiling integration.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The system achieves reduced contrast sensitivity and scalable lighting effects by diffusing light through a combination of reflective and translucent walls, enabling controlled light distribution and optical effects without direct escape from the viewer side.

Implementation Method 1

the first wall part is diffuse reflective for the first device light; the chamber wall part is diffuse reflective for the first device light

Methodology Applied
Scientific EffectDiffuse reflection: Reflection

Implementation Method 2

the second wall part is translucent for the first device light

Methodology Applied
Scientific EffectTranslucency:

Data Source

PatentEP4532974B1Light exit window having adjustable contrast sensitivity
Publication Date: 2026.03.25 SIGNIFY HOLDING BV
  • EP4532974B1 patent drawingFigure 1A(I)~1A(III)
  • EP4532974B1 patent drawingFigure 1B(I)~1B(III)
  • EP4532974B1 patent drawingFigure 2

AI summary

: The invention provides a light generating system (1000) comprising a first light generating device (110) and a unit (1100), wherein: (a) the first light generating device (110) is configured to provide first device light (111) having a wavelength in the visible wavelength range; (b) the unit (1100) comprises in cross-sectional view an open hollow part (400) and a closed hollow part (500); wherein the unit (1100) comprises a viewer side (1101); wherein relative to the viewer side (1101), the open hollow part (400) is concave; (c) the open hollow part (400) comprises a first wall part (451); wherein the first wall part (451) is diffuse reflective for the first device light (111); (d) the closed hollow part (500) comprises a chamber wall (501) comprising (a) a second wall part (452), wherein the second wall part (452) is translucent for the first device light (111), and (b) a chamber wall part (453), wherein the chamber wall part (453) is diffuse reflective for the first device light (111); (e) the unit (1100) comprises a wall element (450) comprising the first wall part (451) and the second wall part (452); (f) the first light generating device (110) is configured in the open hollow part (400); wherein the first light generating device (110) is configured to irradiate (i) at least part of the first wall part (451) and (ii) at least part of the second wall part (452); and (g) the unit (1100) and the first light generating device (110) are configured such that first device light (111) does not directly escape from the viewer side (1101); and wherein the closed hollow part (500) is configured such that at least part of the first device light (111) entering the closed hollow.