Silicate Glass Microchannel Plates for Direct Digital Image Intensifiers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image intensifiers using microchannel plates (MCPs) with high lead oxide content are prone to failure due to brittleness, requiring individual manufacturing to prevent breakage, which increases costs and decreases throughput, and lack the ability to produce digital images directly.
Innovation Solution
The development of image intensifier systems using MCPs with a silicate glass substrate and an electron-emitting semiconducting layer, integrated with a photocathode and phosphorescent layer within a vacuum cavity, and a CMOS imaging array to convert photons into digital images, allowing for high-volume wafer-level processing and eliminating the need for fiber optic bundles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional MCPs with high lead oxide content are used, then electrical characteristics necessary for electron generation are improved, but brittleness increases leading to device failure
Solution Approach 1:
The patent uses a composite material system consisting of a silicate glass substrate combined with a deposited electron-emitting semiconducting layer. This composite structure provides both mechanical robustness from the silicate glass and the necessary electrical characteristics from the semiconducting layer, eliminating the need for high lead oxide content in the bulk material.
Solution Approach 2:
The patent extracts the electron-emitting function from the bulk lead oxide material and places it in a separate deposited semiconducting layer on the surface of a robust silicate glass substrate. This separation allows the bulk material to provide mechanical strength while the surface layer provides electrical functionality.
2Reliability
If extreme care is taken during manufacturing to prevent breakage, then device reliability is improved, but manufacturing cost increases and throughput decreases
Solution Approach 1:
The patent changes the material parameters of the MCP from brittle high-PbO glass to a composite of robust silicate glass with a thin semiconducting layer. This parameter change in material composition and structure enables the device to withstand normal manufacturing handling without requiring extreme care, thereby increasing throughput and reducing costs.
3Ease of operation
If fiber optic bundles are used to transfer analog images, then image transmission is achieved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the mechanical fiber optic bundle transmission system with a direct digital imaging system. The imaging array converts photons directly into digital signals, eliminating the need for physical light transmission through fiber bundles and subsequent analog processing.
Solution Approach 2:
The imaging array serves multiple functions: it directly converts photons to digital images, provides digital signal processing capability, and eliminates the need for separate fiber optic transmission and analog-to-digital conversion components. This multi-functionality reduces overall system complexity.
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 solution enhances the robustness and manufacturing efficiency of image intensifiers, enabling the production of digital images while reducing costs and improving throughput by using less fragile materials and integrating imaging arrays directly with the phosphorescent layer.
Implementation Method 1
An electron emitting photocathode may be disposed within the vacuum cavity for generating electrons from electromagnetic radiation transmitted through the second surface of the first substrate
Implementation Method 2
As high-energy electrons strike the conductive microchannels (which are typically tilted at an angle away from normal to encourage collisions with the microchannels' inner surfaces), the interaction causes the release of additional electrons in a process commonly referred to as secondary cascaded emission
Implementation Method 3
a phosphorescent layer disposed within the vacuum cavity and adjacent the output ends of the plurality of microchannels of the MCP, wherein the imaging array is configured to image one or more photons generated by the phosphorescent layer in response to the plurality of electrons transmitted by the outlet ends of the plurality of microchannels
Data Source
AI summary
Image intensifier systems incorporating a microchannel plate (MCP) and methods for producing the same are disclosed. In some examples, a device is disclosed that includes a first substrate having a radiation-receiving first surface and an opposed second surface through which electromagnetic radiation is transmitted. A second substrate is coupled to the first substrate to define a vacuum cavity therebetween. An electron-emitting photocathode is disposed within the vacuum cavity for generating electrons from electromagnetic radiation transmitted through the second surface. A microchannel plate is disposed within the vacuum cavity and defines microchannels extending from an input end to an output end. Each of the microchannels is configured to generate electrons in response to an electron generated by the photocathode being received through the input end of the respective microchannel. A phosphorescent layer also is disposed within the vacuum cavity and adjacent the output ends of the microchannels of the microchannel plate.