Light Box with Invisible Edges via Tensioned Panel

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Large light boxes require stiffening elements to maintain rigidity, which are visible through translucent walls, compromising aesthetics, and existing solutions fail to provide a rigid structure without visible reinforcement when complete transparency is desired.

Innovation Solution

A light box design featuring a translucent side wall and bottom wall formed by a single sheet, tensioned by transparent or translucent panels that are attached to a spar at the upper edge of the side wall, allowing for hidden reinforcement and colored light highlighting at intersections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If stiffening elements are added to large light boxes to maintain rigidity, then structural strength is improved, but the aesthetic appearance deteriorates due to visible shadows through translucent walls

Engineering Contradiction:
Improvestructural rigidityVSAvoidaesthetic appearance
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent removes the traditional transverse bar stiffening elements that project into the light box interior and cast visible shadows. Instead, it uses a metal frame positioned on the underside of the box that provides structural support without interfering with the light transmission or aesthetic appearance of the translucent walls.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The stiffening structure is moved from the interior dimension (where it would cast shadows) to the exterior underside dimension, where it provides necessary structural support while remaining invisible from the viewing perspective through the translucent walls.

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

2Strength

If a metal frame is placed on the underside of the box to maintain rigidity, then structural strength is improved, but the aesthetic appearance deteriorates because the frame becomes visible through transparent walls

Engineering Contradiction:
Improvestructural rigidityVSAvoidaesthetic appearance
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent applies different transparency qualities to different parts of the structure: the side and bottom walls are made transparent or translucent for aesthetic purposes, while the top surface and underside frame can be opaque metal, creating a localized quality distribution that satisfies both aesthetic and structural requirements.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The metal frame is positioned in a different spatial dimension (on the underside) where it provides structural support without being visible through the transparent side and bottom walls, effectively separating the structural function from the aesthetic view.

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

3Strength

If transverse bars are used to stiffen the box, then structural rigidity is improved, but light transmission deteriorates due to shadow casting on the translucent sheet

Engineering Contradiction:
Improvestructural rigidityVSAvoidlight transmission
Core Design Contradiction:
StrengthVSIllumination intensity

Solution Approach 1:

The patent extracts the stiffening function from the interior space where transverse bars would block and shadow the light. By relocating the structural support to an external metal frame on the underside, light transmission through the translucent walls is maintained without interruption or shadowing.

Inventive Principle:
Principle #2Taking out (Extraction)

Data Source

PatentEP2157361B1Light box with invisible edges
Publication Date: 2011.06.29 NORMALU
  • EP2157361B1 patent drawingFigure 1

AI summary

The box (1) has a translucent lower wall (3) including a translucent layer (4) fixed in a longeron (6) at a level of an upper edge of a lateral wall (2). The layer is placed in tension by a translucent or transparent panel (5). The panel has a lower face that is in support at an interior of the box. A median plane of an edge of the panel is merged with a plane passing through centre of a light source (8), and intersects the lower wall and the lateral wall. An upper lateral edge of the translucent or transparent panel is fixed to the longeron. The panel is made of Plexiglas(RTM: thermoplastic polymer of methyl methacrylate), Lucite(RTM: transparent thermoplastic acrylic resin), Perspex(RTM: acrylic), Limacryl(RTM: transparent thermoplastic acrylic resin) or Vitroflex(RTM: methyl polymethacrylate).