Light Emitting Device Reflection Control Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional light emitting devices for vehicle lamps experience difficulties in maintaining desired luminous intensity distribution and reducing the light emitting area while ensuring a clear outline, due to unwanted light reflection and emission from non-intended areas.
Innovation Solution
A light emitting device with a wavelength converting member and a reflection control structure that includes a reflection film and an anti-reflection film, which controls light emission to minimize luminous intensity distribution changes and reduces the light emitting area by ensuring light is emitted only from the intended face.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a metal film is formed on the wavelength converting member to reduce the light emitting area, then brightness per unit area increases and device size reduces, but the outline of the light emitting face becomes unclear
Solution Approach 1:
The wavelength converting member is divided into two distinct regions: a light emitting face without metal film for clear outline definition, and a light non-emitting face with metal film for brightness enhancement and size reduction. This segmentation resolves the contradiction by spatially separating the functions of outline clarity and brightness concentration.
Solution Approach 2:
Different surface treatments are applied to different regions of the wavelength converting member: the light emitting face maintains a reflective resin surface for clear light emission and outline visibility, while the light non-emitting face is covered with a metal film to reduce light emission and enhance brightness per unit area at the intended emitting regions.
2Power
If light is emitted from the surrounding part of the defined light emitting face, then the light emitting area appears larger, but the outline visibility degrades
Solution Approach 1:
The wavelength converting member is segmented into a light emitting face and a light non-emitting face, with the metal film strategically placed only on the non-emitting portions. This ensures that light is emitted only from the intended face area, maintaining sharp outline visibility while preserving total light output.
Solution Approach 2:
The metal film on the light non-emitting face converts potentially harmful stray light emission into beneficial light reflection toward the light emitting face. This reduces unwanted emission from surrounding areas while maintaining or enhancing total light output through controlled reflection.
3Area of stationary object
If the light emitting area is reduced to increase brightness per unit area, then device size reduces, but the outline becomes less distinct
Solution Approach 1:
The wavelength converting member is divided into light emitting and light non-emitting faces, with the metal film applied only to the non-emitting portions. This segmentation allows the light emitting face to maintain a larger area for clear outline definition while the metal film on the non-emitting face reduces the effective light emitting area to increase brightness per unit area.
Solution Approach 2:
Different regions of the wavelength converting member have different optical properties: the light emitting face has a reflective resin surface for clear outline and light emission, while the light non-emitting face has a metal film to reduce emission area and enhance brightness concentration at the emitting face.
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 solution maintains consistent luminous intensity distribution and allows for a sharp outline by preventing interference from reflected light, thus achieving the desired luminous intensity distribution and reducing the light emitting area effectively.
Implementation Method 1
the reflector resin reflects the light emitted from the side faces of the light emitting element and wavelength converting member to turn the light toward the light emitting face
Implementation Method 2
the reflection control structure includes a reflection film on the wavelength converting member and an anti-reflection film on the reflection film
Implementation Method 3
a phosphor-containing wavelength converting member on its light emitting element
Implementation Method 4
a wavelength converting member including a first face and a second face, wherein light emitted from the light emitting element enters in through the first face
Data Source
AI summary
The light emitting device comprising a light emitting element; and a wavelength converting member having a first face and a second face, in which light emitted from the light emitting element enters in through the first face, and a part of the second face serves as a light emitting face, wherein the light emitting element further comprises a reflection control structure around the light emitting face of the second face, and the reflection control structure comprises a reflection film on the wavelength converting member and an anti-reflection film on the reflection film.