Field Emission Device Fluorescent Layer Alignment
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Solution Overview
Problem
Field emission devices (FEDs) face alignment errors between the fluorescent layer and electron emitters during manufacturing, leading to image distortion and aberration, especially when the device becomes bent or distorted.
Innovation Solution
The FED design involves forming the fluorescent layer directly on the cathode substrate, ensuring it faces the anode, and using flexible materials for the cathode and anode substrates to maintain alignment even when the device is bent or distorted, with electron emitters made of materials like carbon nanotubes and a vacuum-sealed interspace for optimal electron emission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If different colored fluorescent powders are coated on selective portions of the anode to form fluorescent units, then the FED can produce desired images with various colors, but alignment errors occur between fluorescent units and electron emitters during manufacturing, leading to image distortion
Solution Approach 1:
Instead of forming the fluorescent layer on the anode substrate as in conventional FEDs, this patent inverts the approach by forming the fluorescent layer directly on the cathode substrate. This reversal of the layer formation location eliminates the need for precise alignment between separately formed fluorescent units and electron emitters, as the fluorescent layer is created in direct contact with the cathode where the electron emitters are located.
Solution Approach 2:
The patent merges the formation of the fluorescent layer with the cathode structure by depositing the fluorescent material directly onto the cathode substrate in the same vacuum chamber where electron emitters are formed. This combining of operations ensures that the fluorescent layer and electron emitters are co-formed with inherent alignment, eliminating the separate alignment step that causes manufacturing precision issues.
2Adaptability or versatility
If the FED is distorted or folded, then the device can be transformed to different shapes, but the electron emitters and fluorescent layer become misaligned or displaced, producing image aberration
Solution Approach 1:
By merging the fluorescent layer formation with the cathode structure through direct deposition on the cathode substrate, the patent creates an integrated assembly where the fluorescent layer moves with the cathode during flexing or distortion. This combined structure maintains relative alignment between the electron emitters and fluorescent material even when the device is transformed to different shapes.
Solution Approach 2:
The cathode substrate acts as an intermediary that mechanically couples the electron emitters and the fluorescent layer. When the device is distorted or folded, the cathode substrate ensures that both the electron emitters and fluorescent layer undergo the same deformation, maintaining their relative positions and preventing misalignment that would occur if they were separately mounted on different substrates.
3Productivity
If the fluorescent layer is formed on the anode substrate at a distance from the cathode, then the FED can operate with a vacuum interspace, but alignment errors and image distortion occur due to the interspace
Solution Approach 1:
The patent inverts the conventional location of the fluorescent layer by placing it on the cathode substrate instead of the anode substrate. This inversion eliminates the vacuum interspace between the fluorescent layer and electron emitters, allowing for direct alignment during the formation process while still maintaining the vacuum environment necessary for electron emission and light generation.
Solution Approach 2:
The fluorescent layer is formed in advance on the cathode substrate in the same vacuum chamber where the electron emitters are created. This preliminary formation ensures that the fluorescent material is already in position and properly aligned with the electron emitters before the device is sealed and put into operation, eliminating the need for subsequent alignment adjustments.
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 ensures accurate and stable alignment between the fluorescent layer and electron emitters, minimizing image distortion and maintaining image quality even when the device is flexed or bent, thereby improving the reliability and performance of FEDs.
Implementation Method 1
The electrons are generally emitted from micron-sized or nanometer-sized tips (i.e., electron emitters) in a strong electric field.
Implementation Method 2
The electrons are accelerated and then collide with the fluorescent material, thereby emitting the light.
Data Source
AI summary
A field emission device includes a transparent anode substrate, an anode, a cathode substrate, a cathode, and a fluorescent layer. The anode is formed on the anode substrate. The cathode is formed on the cathode substrate. The cathode faces toward the anode and is spaced therefrom at a predetermined distance. The fluorescent layer is formed on the cathode and faces toward the anode. A method for manufacturing the field emission device is also disclosed.