Night Vision Tube Display Integration for Contrast and Dazzle Control
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Solution Overview
Problem
Existing night vision devices struggle with integrating additional information displays without compromising the focal distance, image size, or contrast, and are prone to user dazzle from high luminance displays.
Innovation Solution
A night vision device with a thin glass plate or thin film display integrated within the light intensifier tube, powered and controlled by a module, maintains image quality and contrast by adjusting display luminance based on anode current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a microdisplay is integrated orthogonally to the optical axis downstream of the light intensifier tube, then data display functionality is added, but the surface area of the exit pupil decreases and the image size seen through the eyepiece lens decreases
Solution Approach 1:
The display is arranged in the same dimension as the light guide output (planar configuration), rather than orthogonally. The display is positioned at the outlet of the light intensifier tube in the optical path, allowing it to share the same exit pupil area without blocking it, thus adding display functionality while maintaining full image area.
2Adaptability or versatility
If a microdisplay is integrated orthogonally to the optical axis, then data display functionality is added, but the arrangement is not mechanically stable and requires modification of focal distance
Solution Approach 1:
The display is merged with the light intensifier tube assembly, specifically positioned at the outlet of the light guide in the same housing. This integration ensures mechanical stability and eliminates the need for separate mounting structures that would compromise stability or require focal distance adjustments.
3Illumination intensity
If the display luminance is increased to improve visibility, then display readability improves, but the user may be dazzled when the luminance at the outlet of the light intensifier tube is low
Solution Approach 1:
The control module monitors the luminance output of the light intensifier tube and dynamically adjusts the display luminance accordingly. When the intensifier tube output is low, the display luminance is reduced to prevent dazzle; when the intensifier tube output is high, the display luminance can be increased for better readability, maintaining a balanced visual experience.
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
Enables retrofitting existing devices with integrated displays that maintain image sharpness and contrast, preventing user dazzle by dynamically controlling display luminance relative to night vision image intensity.
Implementation Method 1
a photocathode, 121, receiving the light having crossed the objective lens, and converting the photons thus received into photoelectrons
Implementation Method 2
a microchannel wafer or MCP, 122, playing the role of an electron multiplier by generating secondary electrons from the photoelectrons
Implementation Method 3
a phosphor screen, 123, coupled to an anode, converting the flux of secondary electrons into a light flux
Implementation Method 4
a display in the form of a thin glass plate or of a thin film comprising light-emitting elements
Data Source
AI summary
A night vision device includes a binocular body in which is mounted, along an optical axis, an objective lens, a light intensifier tube, a light guide, and an eyepiece lens. The light intensifier tube includes a photocathode, a microchannel wafer, a phosphor screen intended to deliver a night vision image and a light guide having an input side contiguous to the phosphor screen and an output side intended to form an image in the focal plane of the eyepiece lens. The light intensifier tube further includes a display in the form of a thin glass plate or of a thin film comprising light-emitting elements, the thin plate/the thin film being directly arranged on the output side of the light guide. A power supply and control module, housed within the tube body, at the periphery of the light guide, delivers the respective bias voltages of the different elements of the light intensifier tube and controls the luminescence of the light-emitting elements of the display.