Vehicle Interior Molded Part Backlighting with Structured Recesses

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Solution Overview

Problem

Existing molded parts for vehicle interiors face challenges in achieving precise backlighting of symbols or recesses, especially in poor lighting conditions, due to issues with scattered light affecting the visibility and appearance of large or large-area designs.

Innovation Solution

The solution involves a molded part with a capacitive sensor and a structured light-transmitting recess design, where the sensor reacts to operator movement, and a transparent or translucent protective layer is applied to minimize scattered light, with a diffuser option between the carrier and plastic film for targeted illumination.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a plastic film with opaque printed layer and recesses is used for backlighting, then symbols or recesses can be illuminated, but scattered light causes other symbols to be unintentionally illuminated and visibility is reduced

Engineering Contradiction:
Improvebacklighting intensityVSAvoidscattered light
Core Design Contradiction:
Illumination intensityVSObject-affected harmful factors

Solution Approach 1:

A carrier with windows is introduced as an intermediary component between the light source and the plastic film. The carrier selectively transmits light only through specific windows aligned with desired recesses, while blocking light in other areas. This mediator structure prevents scattered light from reaching unintended symbols, solving the problem of unwanted illumination while maintaining effective backlighting of target symbols.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If the carrier is made transparent to allow light transmission, then backlighting is achieved, but stray light illuminates areas where illumination is not desired

Engineering Contradiction:
Improvelight transmissionVSAvoidtargeted illumination precision
Core Design Contradiction:
Illumination intensityVSManufacturing precision

Solution Approach 1:

The carrier is designed with spatially varying optical properties: it has transparent windows in specific locations where light transmission is desired, and opaque or light-blocking material in other areas. This local differentiation of transparency allows precise control over where light passes through, enabling targeted illumination of specific symbols or recesses while preventing stray light in other areas.

Inventive Principle:
Principle #3Local quality

3Manufacturing precision

If light elements are positioned close to the plastic film to reduce stray light, then targeted illumination is improved, but the structural complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvelight positioning precisionVSAvoidstructural complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The carrier and light source are merged into a single integrated component. The light elements are embedded within or attached to the carrier structure, eliminating the need for separate mounting brackets, adhesives, or alignment mechanisms. This integration simplifies the overall structure, reduces the number of parts, and facilitates manufacturing while maintaining precise positioning of light sources relative to the plastic film.

Inventive Principle:
Principle #5Merging (Combining)

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 enables precise and targeted backlighting of specific symbols while keeping others dark, enhancing visibility and appearance under various lighting conditions.

Implementation Method 1

at least one functional element comprising at least one light element and/or at least one light guide

Methodology Applied
Scientific EffectLight emission: Light Emitting Diode

Implementation Method 2

the carrier is designed as a diffuser. Alternatively or additionally, a diffuser can be provided between the carrier and the plastic film

Methodology Applied
Scientific EffectLight diffusion: Diffusion

Implementation Method 3

the sensor element comprises at least one capacitive sensor or is at least one capacitive sensor, wherein the capacitive sensor is designed in such a way that it reacts to an approach and/or movement, in particular of the finger, of an operator

Methodology Applied
Scientific EffectCapacitive sensing: Capacitance

Data Source

PatentEP3048015B1Moulded part, in particular decorative part and/or trim for a vehicle interior designed as a moulded part, and method for producing a moulded part
Publication Date: 2019.06.19 NOVEM CAR INTERIOR DESIGN GMBH
  • EP3048015B1 patent drawingFigure 1
  • EP3048015B1 patent drawingFigure 2~3

AI summary

The invention relates to a molded part (10), in particular a decorative part and/or trim part for a vehicle interior, comprising a decorative layer formed by a plastic film (11), on the reverse side of which a carrier (12) is arranged, in particular injection-molded. The invention is characterized in that the plastic film (11) has at least one opaque printed layer (19) with at least one recess (13) for light transmission. The invention further relates to a method for manufacturing a molded part.