Semiconductor Light Emitting Element with Segmented Cathode Electrode
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing flash light devices with multiple light-emitting elements face challenges in forming desired light distribution patterns, particularly when objects are positioned off-center, due to difficulties in independently controlling light-emitting regions and increased component count and size.
Innovation Solution
A semiconductor light-emitting element with a cathode electrode configuration featuring extension portions that reduce electric current density at terminal ends, allowing for low light emission intensity regions between light-emitting portions, which are perceived as separate light sources, enabling precise light distribution control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If multiple light-emitting elements are used to facilitate light distribution control, then light distribution control is improved, but device size and component count increase
Solution Approach 1:
The cathode electrode is divided into multiple electrode pieces (first electrode piece, second electrode piece, etc.) that are spatially separated. Each electrode piece independently controls a specific light-emitting region, enabling flexible light distribution patterns without requiring multiple separate light-emitting elements. This segmentation allows the single light-emitting element to function as multiple controlled regions.
Solution Approach 2:
Different regions of the light-emitting element are given different functional qualities through the electrode piece configuration. By controlling which electrode pieces receive drive current, specific local regions can be activated or deactivated to create desired light distribution patterns (unbiased, left-biased, right-biased), making each region adaptable to different operational requirements.
2Ease of operation
If multiple light-emitting elements are used to facilitate light distribution control, then light distribution control is improved, but mounting substrate area increases
Solution Approach 1:
Multiple functional electrode pieces are integrated onto a single light-emitting element rather than using separate light-emitting elements. This merging allows the control functionality of multiple elements to be achieved within the footprint of one element, significantly reducing the required mounting substrate area while maintaining the ability to control different light-emitting regions independently.
Solution Approach 2:
Instead of arranging multiple light-emitting elements in a two-dimensional array on the mounting substrate, the invention uses a single element with electrode pieces distributed across its surface area. This transitions the control architecture from a multi-element spatial arrangement to a single-element internal segmentation, reducing the mounting substrate footprint.
3Adaptability or versatility
If light-emitting regions are divided and individually controlled, then light distribution flexibility is improved, but forming desired light distribution patterns becomes more difficult
Solution Approach 1:
The electrode pieces are positioned asymmetrically relative to the light-emitting region, with each electrode piece strategically located to control access to specific portions of the light-emitting surface. This asymmetric arrangement, combined with the extension portions that reduce current density at terminal ends, creates natural current flow patterns that facilitate forming unbiased, left-biased, and right-biased light distribution patterns through simple electrode activation sequences.
Solution Approach 2:
The extension portions of the electrode pieces act as intermediaries between the power supply and the light-emitting regions. By designing these extension portions with increasing resistance along the extension direction, the system creates intermediate current density zones that naturally form low light emission intensity regions between active light-emitting portions, simplifying the control of light distribution patterns.
4Illumination intensity
If electrode extension portions are added to reduce current density, then light emission uniformity is improved, but electrode structure complexity increases
Solution Approach 1:
The extension portions are pre-designed into the electrode structure with specific geometric characteristics (increasing width along the extension direction) that inherently create the desired current density distribution. This preliminary structural design eliminates the need for complex external current control mechanisms, as the geometry itself performs the current density equalization function.
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 configuration allows for flexible and accurate light distribution patterns, including unbiased, left-biased, and right-biased distributions, by independently controlling light-emitting regions, reducing component size, and enhancing operational stability.
Implementation Method 1
the extension portions have a resistance component that increases along the extension direction of the extension portions
Implementation Method 2
a light-emitting element, which is a nitride semiconductor light-emitting element, having a light-emitting portion, which emits light, and a cathode electrode, which is connected to a light-emitting region of the light-emitting element
Data Source
Figure 1
Figure 2A~2C
Figure 3A~3D
AI summary
There is provided a light-emitting element which includes a first semiconductor layer, a second semiconductor layer having an electrical conductivity that is different from that of the first semiconductor layer and an active layer disposed between the first and second layers, and a first and second electrodes respectively disposed on surfaces of the first and second semiconductor layers. The first electrode comprises a plurality of electrode pieces separated from each other; and each of the electrode pieces comprises a power feed pad, and an extended portion connected to the pad and that extends in a direction away from the pad, and a terminal end portion of the extended portion of an electrode piece is opposed to a terminal end portion of the extended portion of the other electrode piece across a gap.