Lighting Device with Dual Phosphor Layers for Camera Flash
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Solution Overview
Problem
Portable telephone cameras struggle with capturing clear images in low light conditions, particularly when photographing human subjects, due to inadequate brightness and poor color rendering properties of existing flashing devices, which are either limited by poor color rendering or complex control circuits.
Innovation Solution
A lighting device comprising a supporting member with a light emitting element, a first fluorescent layer containing organic phosphor on the side surfaces, and a second fluorescent layer containing inorganic phosphor covering the light emitting surface, where the second fluorescent layer is interposed between the light emitting element and the first fluorescent layer, enhancing brightness and color rendering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If white LED devices using blue LED and phosphor are used, then brightness is improved, but color rendering properties deteriorate
Solution Approach 1:
The patent combines multiple types of light emitting elements (blue LED and ultraviolet LED) in a single lighting device, along with multiple phosphor layers (yellow phosphor and red phosphor), to achieve both high brightness and excellent color rendering properties simultaneously
Solution Approach 2:
The patent uses composite phosphor materials including yellow phosphor (Y3Al5O12:Ce) and red phosphor (CaAlSiN3:Eu) in combination with blue and ultraviolet LED to create a lighting device with superior color rendering and brightness
2Reliability
If combination of red, green and blue emitting diodes is used, then color rendering properties are improved, but device complexity increases
Solution Approach 1:
The patent merges red, green, and blue light generation into a single lighting device by combining blue LED with red and green phosphors, eliminating the need for separate RGB LED chips and complex control circuits
Solution Approach 2:
The patent changes the approach from directly controlling multiple LED chips to using phosphor conversion, where a single blue LED excites multiple phosphors to generate the desired spectrum, simplifying the control system
3Reliability
If ultraviolet LED and red LED chips are combined, then color rendering is improved, but brightness and driving complexity remain problematic
Solution Approach 1:
The patent combines ultraviolet LED with both yellow and red phosphors in a single device, achieving high brightness through the efficient ultraviolet-to-yellow phosphor conversion while adding red phosphor for excellent color rendering
4Illumination intensity
If white LED using blue LED and phosphor is used, then brightness is achieved, but red component intensity becomes weak
Solution Approach 1:
The patent combines yellow phosphor (for brightness) and red phosphor (for red component intensity) in the same lighting device, allowing both functions to be achieved simultaneously through phosphor down-conversion of blue and ultraviolet LED light
Solution Approach 2:
The patent uses composite phosphor materials including yellow phosphor (Y3Al5O12:Ce) and red phosphor (CaAlSiN3:Eu) to create a lighting device with both high brightness and strong red component for superior color rendering
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 provides a high-intensity, long-lasting lighting device with excellent color rendering properties, suitable for capturing clear images of human subjects even at a distance, while preventing organic phosphor deterioration and maintaining efficient emission intensity.
Implementation Method 1
a second fluorescent layer containing only an inorganic phosphor and disposed on the supporting member, wherein the second fluorescent layer is disposed so as to cover the upper and side surfaces of the light emitting element
Implementation Method 2
a first fluorescent layer containing an organic phosphor and disposed on the supporting member
Data Source
AI summary
A lighting device including a supporting member, a light emitting element disposed on the supporting member, and emitting light from an upper and side surfaces thereof, a first fluorescent layer containing an organic phosphor and disposed on the supporting member, and a second fluorescent layer containing only an inorganic phosphor and disposed on the supporting member, wherein the second fluorescent layer is disposed to cover the upper and side surfaces of the light emitting element, and the first fluorescent layer is disposed on at least side surface of the light emitting element with the second fluorescent layer being interposed between the light emitting element and the first fluorescent layer.