LED Package with Color Filter for Blue Light Blocking
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Solution Overview
Problem
Conventional light emitting diode packages that convert blue or ultraviolet light to red light suffer from reduced productivity and increased size due to thick phosphor layers, which also limit color gamut and allow unwanted blue light emission.
Innovation Solution
A light emitting diode package with a phosphor layer that converts blue or ultraviolet light to red light, combined with a color filter layer to block specific wavelengths, maintaining a compact size and achieving desired color gamut by blocking blue light emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the thickness of the phosphor layer is increased to minimize blue light emission, then blue light blocking is improved, but the package size increases and productivity decreases
Solution Approach 1:
The solution divides the blue light blocking function into two separate components: a phosphor layer for wavelength conversion and a color filter layer for blue light absorption. This segmentation allows each layer to be optimized independently, with the color filter layer being thin yet effective, thus preventing blue light emission without increasing package size.
Solution Approach 2:
A color filter layer is introduced as an intermediary component between the phosphor layer and the external environment. This intermediary layer specifically absorbs blue light wavelengths while allowing red light to pass through, achieving blue light blocking without requiring increased phosphor layer thickness.
2Object-affected harmful factors
If the thickness of the phosphor layer is increased to minimize blue light emission, then blue light blocking is improved, but productivity decreases
Solution Approach 1:
By segmenting the blue light blocking function into a phosphor layer and a separate color filter layer, the manufacturing process can be optimized. The color filter layer can be applied as a thin coating using conventional techniques, reducing material consumption and simplifying the manufacturing process compared to depositing thick phosphor layers.
Solution Approach 2:
The invention changes the approach from increasing phosphor layer thickness to introducing a color filter layer with specific optical properties. This parameter change allows for thin film deposition techniques that are faster and more efficient than conventional phosphor layer deposition methods.
3Illumination intensity
If a conventional phosphor layer structure is used, then red light emission is achieved, but color gamut is limited due to blue light leakage
Solution Approach 1:
The color filter layer acts as an intermediary that selectively removes blue light wavelengths from the emitted spectrum. This mediation enables the package to achieve pure red light emission without blue light contamination, significantly expanding the color gamut while maintaining red light intensity.
Solution Approach 2:
The invention utilizes the color filter layer's ability to selectively absorb blue light wavelengths and transmit red light. This color-selective transmission changes the overall emission spectrum from a mix of blue and red to pure red, thereby expanding the achievable color gamut.
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 effectively reduces blue light emission while maintaining red light output, enhancing color gamut without increasing the package size, allowing for improved color representation in lighting applications.
Implementation Method 1
a phosphor layer 13 covers the light emitting diode chip 12 to convert blue light or ultraviolet light into red light
Implementation Method 2
a color filter layer disposed to cover an upper portion of the phosphor layer, the color filter being configured to block light having a predetermined wavelength range from being emitted through the phosphor layer
Data Source
AI summary
A light emitting device including a light emitting diode chip configured to emit a primary light having a peak wavelength, a wavelength conversion layer disposed to cover an upper portion of the light emitting diode chip and configured to convert a wavelength of the primary light emitted from the light emitting diode chip, and a color filter layer disposed to cover an upper portion of the wavelength conversion layer and configured to block at least a portion of the primary light from being emitted through the wavelength conversion layer and transmit light having a wavelength longer than the peak wavelength, in which the at least portion of the primary light includes a wavelength equal to or less than the peak wavelength.