Field Emission Cathode for Planar Light Source
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Solution Overview
Problem
Conventional backlight modules for liquid crystal displays require intermediate optical manipulation to achieve uniform flat lighting, resulting in light energy loss and increased manufacturing costs due to the need for precise optical components like micro-lens and light guide plates, while field emission devices have not provided a satisfactory planar light source.
Innovation Solution
A light source apparatus featuring a field emission cathode with electrically conductive carriers and radially extending field emitters, optionally with an anode and grid electrode, configured to produce a planar light source without the need for additional optical components, utilizing materials like metals, non-metals, and one-dimensional nanomaterials for enhanced electron emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If conventional backlight modules use optical manipulation techniques with micro-lens and light guide plates, then uniform flat lighting is achieved, but light energy is lost and manufacturing costs increase
Solution Approach 1:
The cathode is divided into multiple conductive carriers arranged in parallel, each carrier having multiple field emitters. This segmentation allows direct generation of planar light source without requiring optical manipulation components, thereby reducing light energy loss while maintaining uniform illumination.
Solution Approach 2:
The patent introduces a grid electrode as an intermediary component between the cathode and anode, which helps in controlling and uniformizing the electric field distribution, enabling direct planar light generation without optical manipulation while maintaining illumination uniformity.
2Illumination intensity
If conventional backlight modules use optical manipulation techniques with micro-lens and light guide plates, then uniform flat lighting is achieved, but device complexity and manufacturing costs increase
Solution Approach 1:
The patent extracts and eliminates the optical manipulation components (micro-lens, light guide plates) from the conventional backlight module, replacing them with a field emission cathode structure that directly generates planar light source, thereby simplifying device complexity while maintaining uniform illumination.
Solution Approach 2:
The conductive carriers serve multiple functions: they provide electrical conduction, structural support, and enable direct planar light generation. This multi-functionality eliminates the need for separate optical components, reducing device complexity and manufacturing costs.
3Reliability
If field emission devices use traditional cathode structures, then electron emission is achieved, but planar light source quality is insufficient
Solution Approach 1:
Each conductive carrier is equipped with multiple field emitters positioned at specific locations, creating localized high-quality electron emission points. The parallel arrangement of carriers ensures uniform distribution of emission points across the cathode surface, achieving both reliable electron emission and high-quality planar light source.
Solution Approach 2:
The cathode uses composite structure combining conductive carriers (metal or conductive ceramic) with field emitter materials (such as carbon nanotubes, tungsten, or other emission materials). This composite structure enhances both electron emission reliability and planar light source quality.
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 field emission cathode apparatus provides a planar light source with improved electron-emitting efficiency and reduced manufacturing complexity, eliminating the need for corrective optical components and enhancing brightness and stability, thus offering a cost-effective and efficient illumination solution.
Implementation Method 1
Field emission devices are based on emission of electrons in a vacuum in order to produce visible light. Electrons are emitted from micron-sized tips in a strong electric field
Implementation Method 2
the electrons are accelerated and collide with a fluorescent material. The fluorescent material then emits visible light
Data Source
AI summary
A light source apparatus (8) includes a rear plate (80), a front plate formed with an anode layer (82), and a cathode (81) interposed therebetween. The cathode includes a plurality of electrically conductive carriers (812) and a plurality of field emitters (816) formed thereon. The field emitters are uniformly distributed on anode-facing surfaces of the conductive carriers. Preferably, the field emitters extend radially outwardly from the corresponding conductive carriers. The conductive carriers are parallel with each other, and are located substantially on a common plane. Each of the conductive carriers can be connected with a pulling device arranged at least one end thereof, and an example of the pulling device is a spring. The conductive carriers may be cylindrical, prism-shaped or polyhedral.