Window Shade Perimeter Blockout for Side Light Gaps

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Solution Overview

Problem

Architectural-structure coverings, such as honeycomb shades and Venetian blinds, suffer from unwanted light leakage through gaps between the covering and the window frame or wall due to imperfect mounting, which affects aesthetics and functionality, especially in out-of-skew frames.

Innovation Solution

A perimeter light blockout system with a light blocking device and mounting element that minimizes light leakage by using a U-shaped channel and adjustable mounting extrusion or clips to align with the window frame, incorporating light-absorbing surfaces to reflect light back and prevent contact with the covering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If mounting brackets are used to install the covering inside the window frame, then the covering can be securely mounted, but side gaps are created that allow unwanted light to pass through

Engineering Contradiction:

Improvemounting securityVSAvoidlight leakage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

A light blocking device is introduced as an intermediary element between the covering and the window frame. This device includes a channel that receives the covering and extends across the light gap to the interior side surface of the window frame, effectively blocking light without interfering with the mounting brackets' securing function.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The light blocking device extends in a third dimension (depth) from the front surface of the window frame to the interior side surface, creating a volumetric light barrier rather than relying solely on the two-dimensional coverage of the covering itself.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Ease of operation

If the covering is made narrower to fit within the window frame, then mounting is enabled, but light gaps increase at the sides

Engineering Contradiction:

Improvemounting feasibilityVSAvoidlight gap size

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The light blocking device serves as a mediator that allows the covering to maintain its narrower mounting width while still achieving complete light blockage by extending the blocking function to the interior side surface of the window frame.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If complex actuators such as tilt rods and operating cords are added to the covering, then functionality is improved, but the side gaps become more significant

Engineering Contradiction:

Improvecovering functionalityVSAvoidlight gap prominence

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The light blocking device provides a consistent light barrier regardless of the covering's functional components. The channel design accommodates various actuator configurations while maintaining the light blocking function through its extension to the interior side surface.

Inventive Principle:

Principle #24Intermediary (Mediator)

4Object-affected harmful factors

If the light blocking device contacts the covering, then light blockage is enhanced, but the covering movement is restricted

Engineering Contradiction:

Improvelight blockage effectivenessVSAvoidcovering mobility

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

The system is segmented into distinct functional zones: the channel receives the covering but maintains clearance to allow movement, while the light blocking portion extends beyond the channel to contact the interior side surface of the window frame, ensuring light blockage without restricting covering mobility.

Inventive Principle:

Principle #1Segmentation

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

Effectively blocks unwanted light, maintains covering integrity, and allows for easy alignment and removal for cleaning, enhancing the aesthetic and functional performance of architectural-structure coverings.

Implementation Method 1

incorporating light-absorbing surfaces to reflect light back and prevent contact with the covering

Methodology Applied

Scientific EffectLight absorption and reflection: Absorption (EM radiation)

Data Source

PatentEP4715159A2Perimeter light blockout system and corresponding method for minimizing passing light

Publication Date: 2026.03.25 HUNTER DOUGLAS INC

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AI summary

A perimeter light blockout system for minimizing light leakage between light gaps such as, for example, between the sides of a covering (e.g., shade) of an architectural-structure covering and the interior side surfaces of a window frame, or between the covering and the outer surface of an interior wall is disclosed. The perimeter light blockout system including a light blocking device and a mounting element for coupling the light blocking device to the interior side surface of the window frame, or the outer surface of the interior wall. The light blocking device may include rear and front channel members. The mounting element may be a mounting extrusion. Alternatively, the mounting element may be a spring clip. In use, the light blocking device may be adapted and configured so as not to contact the covering as the covering moves between extended and retracted positions. The mounting element may include a degree of adjustment so that the light blocking device may be aligned with an out-of-skew window frame.