Rear PCB Light Pipe Illuminated Display System

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Solution Overview

Problem

Conventional illuminated display systems face inefficiencies due to complex light pipe designs that are affected by electrical components and mechanical structures, leading to light losses and difficulties in directing light to specific areas of the display panel, making design optimization challenging and costly.

Innovation Solution

Positioning light pipes on the rear surface of the circuit board minimizes obstructions, allowing for minimal changes in light direction and reducing de-collimation, with designs featuring flat wedge portions, branches, and facets that direct light efficiently to the display surface, and incorporating curved internal reflection mirrors and risers to enhance light propagation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If light pipes are positioned between the printed circuit board and display panel to direct light, then light can be delivered to the display panel, but the design becomes complex due to shared space with electrical components and mechanical structures

Engineering Contradiction:
Improvelight delivery efficiencyVSAvoidlight pipe design complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The light pipe is repositioned from the traditional location between the PCB and display panel to the rear surface of the PCB. This dimensional relocation eliminates spatial conflict with electrical components and mechanical structures, allowing for simpler light pipe geometry while maintaining effective light delivery to the display panel through the PCB substrate.

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

Solution Approach 2:

The lighting system is segmented into distinct functional zones: light sources positioned on the rear PCB surface, light pipes routed independently on the rear surface, and light delivery through designated openings in the PCB to the display panel. This segmentation allows each component to be optimized independently without interference from others.

Inventive Principle:
Principle #1Segmentation

2Use of energy by moving object

If complex light pipe structures are used to navigate around electrical components, then light can reach the display panel, but collimation decreases and light losses increase

Engineering Contradiction:
Improvelight utilization efficiencyVSAvoidlight loss
Core Design Contradiction:
Use of energy by moving objectVSLoss of energy

Solution Approach 1:

By moving the light pipe to the rear PCB surface, the light propagation path is simplified and straightened, eliminating the need for complex weaving around components. This maintains better collimation throughout the light path, reducing scattering and absorption losses while improving overall light utilization efficiency.

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

Solution Approach 2:

The light pipe is extracted from the congested space between PCB and display panel and relocated to the rear PCB surface. This separation removes the light pipe from the harmful environment of component obstructions, allowing for a simpler geometry that preserves collimation and minimizes light loss through reduced reflection and scattering events.

Inventive Principle:
Principle #2Taking out (Extraction)

3Use of energy by moving object

If light pipes are positioned on the front surface of the circuit board, then light can be directed to the display panel, but obstructions from electrical components and mechanical structures reduce efficiency

Engineering Contradiction:
Improvelight propagation efficiencyVSAvoidobstructions from components
Core Design Contradiction:
Use of energy by moving objectVSObject-affected harmful factors

Solution Approach 1:

The light pipe is relocated to the rear surface of the PCB, utilizing the unused space on the opposite side of the board from the display panel. This dimensional change completely eliminates obstructions from electrical components and mechanical structures that are located on the front surface, allowing for unobstructed light propagation through designated PCB openings to the display panel.

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

4Use of energy by moving object

If complex light pipe designs are used to navigate component obstructions, then light can reach the display panel, but design optimization becomes difficult and costly

Engineering Contradiction:
Improvelight delivery capabilityVSAvoiddesign optimization ease
Core Design Contradiction:
Use of energy by moving objectVSEase of manufacture

Solution Approach 1:

Relocating the light pipe to the rear PCB surface creates a simplified design with fewer constraints, making computer simulation faster and more accurate. This enables iterative design optimization to be performed efficiently before manufacturing, reducing the number of expensive prototype iterations needed and accelerating the design process.

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

Solution Approach 2:

By extracting the light pipe from the complex front-surface environment and placing it on the rear PCB surface, the design complexity is dramatically reduced. This allows for simpler geometries that are easier to model, simulate, and manufacture, while still achieving effective light delivery to the display panel through optimized opening positions in the PCB.

Inventive Principle:
Principle #2Taking out (Extraction)

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

This approach increases light utilization and efficiency, reduces the number of light sources needed, and simplifies design processes by decoupling lighting and mechanical designs, resulting in cost savings and improved collimation effects.

Implementation Method 1

gradual changes in direction of light propagation by means of total internal reflection on non-parallel light pipe walls

Methodology Applied
Scientific EffectTotal internal reflection: Total Internal Reflection

Implementation Method 2

facets that direct light efficiently to the display surface

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP1720048B1Illuminated display system
Publication Date: 2014.10.15 DELPHI TECHNOLOGIES INC
  • EP1720048B1 patent drawingFigure 1A~1B
  • EP1720048B1 patent drawingFigure 2A
  • EP1720048B1 patent drawingFigure 2B

AI summary

An illuminated display system is disclosed. The illuminated display system includes a circuit board (12) with a front surface (12a) and a rear surface (12b), and a plurality of light-passing holes (30). At least one light pipe (14a-14d) is arranged on the rear surface (12b) of the circuit board (12). The at least one light pipe (14a-14d) includes at least one entrance port (20) and a plurality of corresponding facets (22) and exit ports (23). Each of the plurality of facets (22), exit ports (23), and light passing holes (30) are aligned in a corresponding relationship to the location of individual components (52-58) of a display surface (50) positioned over the front surface (12a) of the circuit board (12).