Tunable Wavelength Micro-LED Pixel for Full-Color Display
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Solution Overview
Problem
Existing display technologies using semiconductor light-emitting elements face challenges in achieving high definition and cost-effectiveness due to the need for multiple sub-pixels per pixel, and controlling multicolor light emission in micro-LEDs is complex, leading to issues like increased cost and decreased yield.
Innovation Solution
A light-emitting device with a combination of first and second light-emitting elements, where the second element's emission color is tunable, is driven using a lighting controller that divides frames into subframes to control light emission periods, allowing for simpler full-color emission by combining fixed and tunable colors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple sub-pixels (RGB) are arranged for each pixel to achieve full-color display, then light emission color variety is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines a fixed-wavelength light-emitting element (first light-emitting element) with a tunable-wavelength light-emitting element (second light-emitting element) into a single pixel unit. This merging allows the pixel to produce multiple colors by varying the drive current to the tunable element, eliminating the need for multiple fixed sub-pixels and reducing device complexity while maintaining full-color capability
Solution Approach 2:
The second light-emitting element with tunable wavelength serves multiple functions: it can emit different colors (green, yellow, orange, red) by adjusting the drive current. This multi-functionality replaces what would traditionally require multiple separate sub-pixels, thereby reducing the number of components needed per pixel
2Adaptability or versatility
If multiple sub-pixels are arranged for each pixel to achieve full-color display, then light emission color variety is improved, but manufacturing cost increases
Solution Approach 1:
By merging a fixed-wavelength element and a tunable-wavelength element into one pixel, the total component count is reduced. This simplifies the manufacturing process, reduces material usage, and lowers production costs compared to assembling multiple fixed sub-pixels for each pixel
Solution Approach 2:
The patent utilizes parameter changes (drive current magnitude) to control the wavelength output of the second light-emitting element. This allows a single component to replace multiple components with different fixed wavelengths, reducing manufacturing complexity and cost
3Adaptability or versatility
If traditional multicolor LED control methods are used, then color control is achieved, but control complexity increases
Solution Approach 1:
The patent employs dynamic control where the drive current magnitude to the second light-emitting element is varied to change its emission wavelength. This dynamic approach allows continuous color adjustment from green to red, providing flexible color control without requiring complex multi-element control circuits
Solution Approach 2:
By changing the drive current parameter (its magnitude), the emission characteristics of the second light-emitting element are controlled. This simple parameter-based control method replaces complex control schemes needed for traditional multicolor LEDs with multiple fixed-wavelength elements
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 efficient multicolor light emission with reduced complexity, avoiding color separation and improving luminance while maintaining high definition without the need for excessive sub-pixels, thus lowering costs.
Implementation Method 1
a plurality of first light-emitting elements 11A each capable of emitting light of a first light emission color and a plurality of second light-emitting elements 11B each capable of emitting light of a second light emission color different from the first light emission color
Implementation Method 2
a light emission color of a second light-emitting element 11B of the plurality of second light-emitting elements 11B is variable in accordance with a drive current
Data Source
AI summary
A light-emitting device includes: a display comprising a plurality of pixels in which a plurality of first light-emitting elements each configured to emit light of a first light emission color and a plurality of second light-emitting elements each configured to emit light of a second light emission color different from the first light emission color are arranged in a predetermined pattern; and a lighting controller configured to supply a drive current to each of the plurality of first light-emitting elements and each of the plurality of second light-emitting elements and control a light emission period of each of the plurality of first light-emitting elements and each of the plurality of second light-emitting elements. A light emission color of a second light-emitting element of the plurality of second light-emitting elements is variable in accordance with a drive current supplied thereto.