Field Emission Display Gate Metal Mesh for Voltage Reduction
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Solution Overview
Problem
Conventional field emission displays (FEDs) require high driving voltages due to the need for a high electric field between electrodes, leading to expensive drive circuits and limitations in brightness due to voltage constraints, especially with the diode type field emission device, which lacks a gate and gate insulating layer, resulting in reliability issues and non-uniform electron emission.
Innovation Solution
Incorporating a gate portion with a metal mesh and dielectric layer between the cathode and anode portions, allowing for adjustable intervals and focused electron emission onto the phosphor, enabling lower row/column driving voltages and enhanced brightness, while allowing independent manufacturing and assembly of the gate portion for simplified manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high electric field is applied between cathode and anode electrodes to enable electron emission, then electron emission efficiency is improved, but driving voltage becomes excessively high requiring expensive drive circuits
Solution Approach 1:
The space between cathode and anode is segmented by introducing a gate electrode at an intermediate position. This divides the single high-voltage gap into two smaller gaps (cathode-gate and gate-anode), allowing the total voltage to be distributed across multiple stages rather than applied across one large gap, thereby reducing the required driving voltage while maintaining effective electron emission.
Solution Approach 2:
A gate electrode is introduced as an intermediary element between the cathode and anode. This gate electrode acts as a mediator that controls and modulates the electric field distribution, enabling electron emission at lower overall driving voltages by creating localized high-field regions near the cathode while maintaining a more manageable voltage gradient toward the anode.
2Power
If the interval between cathode and anode is reduced to lower driving voltage, then power consumption is reduced, but electron emission control becomes difficult and brightness is limited
Solution Approach 1:
By segmenting the electrode structure with an intermediate gate electrode, the patent creates two separate control zones. The gate electrode can be independently controlled to modulate electron emission, providing fine control over emission characteristics even when the overall cathode-anode interval is small, thus maintaining ease of operation while reducing power consumption.
Solution Approach 2:
The gate electrode introduces dynamic control capability to the system. By independently varying the gate voltage, the electric field distribution and electron emission characteristics can be dynamically adjusted, enabling precise control over emission intensity and timing, which overcomes the control difficulties associated with reduced electrode spacing.
3Ease of manufacture
If diode type field emission device is used without gate and gate insulating layer, then manufacturing process is simple, but reliability of electron emission control deteriorates and non-uniform emission occurs
Solution Approach 1:
The patent segments the field emission device into distinct functional regions by introducing a gate electrode and gate insulating layer. This segmentation creates separate control and emission zones, improving reliability of electron emission control. The gate insulating layer specifically prevents direct contact between gate and cathode, ensuring stable electrical isolation and uniform electric field distribution, which addresses the non-uniform emission problem while maintaining manufacturing feasibility.
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 reduces the driving voltage requirements, enhances brightness by focusing electrons effectively, and prevents local arcing, improving the manufacturing productivity and yield of FEDs with high resolution and extended lifespan.
Implementation Method 1
electrons are emitted from the field emitter of the cathode and collide with the phosphor of the anode, thereby displaying an image using the cathodoluminescence of the phosphor
Implementation Method 2
displaying an image using the cathodoluminescence of the phosphor
Implementation Method 3
a dielectric layer formed on at least one region of the metal mesh
Data Source
AI summary
Provided is a field emission display, which includes: a cathode portion including row signal lines and column signal lines in a stripe form allowing matrix addressing to be carried out on a substrate, and pixels defined by the row signal lines and the column signal lines, each pixel having a field emitter and a control device which controls the field emitter with two terminals connected to at least the row signal line and the column signal line and one terminal connected to the field emitter; an anode portion having an anode electrode, and a phosphor connected to the anode electrode; and a gate portion having a metal mesh with a plurality of penetrating holes, and a dielectric layer formed on at least one region of the metal mesh, wherein the gate portion is disposed between the cathode portion and the anode portion to allow the surface where the dielectric layer is formed to be faced to the cathode portion and to allow electrons emitted from the field emitter to collide with the phosphor via the penetrating holes.