Night Vision Device Luminance Ratio Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional night-vision devices for vehicles face challenges in improving image visibility and generating color images, especially when window shields that cut infrared light are used, leading to reduced detection performance due to altered luminance ratios caused by street lights or oncoming vehicles.
Innovation Solution
A night-vision device with a light projecting unit, image pickup unit, and luminance ratio determining unit that adjusts near-infrared ray intensity to maintain a predetermined luminance ratio between near-infrared and visible light luminance values, ensuring the object to be detected is emphasized in the image.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a window shield that cuts infrared light is used to suppress temperature rise in the vehicle interior, then the temperature control is improved, but the intensity of near infrared rays from the object to be detected received by the image pickup device is lowered
Solution Approach 1:
The patent segments the optical filtering function by using separate filters for different wavelength ranges. The window shield blocks far infrared rays to reduce heat, while the near infrared filter selectively transmits near infrared rays (600-800nm) to the image pickup device. This segmentation allows simultaneous achievement of temperature control and near infrared detection.
Solution Approach 2:
The patent introduces a near infrared filter as an intermediary component between the window shield and the image pickup device. This filter mediates the conflict by selectively transmitting near infrared rays while blocking far infrared rays, enabling the window shield to perform its heat-blocking function while allowing the image pickup device to receive sufficient near infrared illumination.
2Measurement precision
If the luminance ratio of near infrared rays to visible light falls outside the predetermined range due to environmental lighting changes, then the detection emphasis is lost, but the environmental lighting conditions vary
Solution Approach 1:
The patent implements a feedback mechanism where the control unit continuously monitors the luminance ratio of near infrared rays to visible light and adjusts the near infrared ray emission intensity accordingly. When the ratio falls outside the predetermined range, the control unit modifies the emission intensity to restore the optimal ratio, ensuring consistent object detection emphasis despite environmental lighting variations.
Solution Approach 2:
The patent makes the near infrared ray emission intensity dynamic rather than fixed. The light emitting unit adjusts its emission intensity in real-time based on environmental lighting conditions and the detected luminance ratio, allowing the system to adapt to varying street lights, oncoming vehicles, and other environmental factors while maintaining optimal detection performance.
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 detection performance by maintaining optimal luminance ratios, even with window shields and varying environmental lighting conditions, resulting in improved image visibility and object detection.
Implementation Method 1
a light projecting unit that emits near infrared rays to a predetermined emission range as a spatial region around a subject vehicle
Implementation Method 2
an image pickup unit that receives a light from a specified space defined as the spatial region around the subject vehicle including the emission range through any of a near infrared filter that passes near infrared rays and a visible light filter that passes visible light
Data Source
AI summary
A night-vision device is provided with a projection unit, an image pickup unit, a luminance ratio determining unit, and a projection control unit. The luminance ratio determining unit determines whether a determination luminance ratio in a set region is within a predetermined luminance range as a luminance ratio at which a subject to be detected forms an emphasized image, said set region having been set at least in a part of an image obtained by means of the image pickup unit. In the cases where the determination luminance ratio is out of the predetermined luminance range, the projection control unit controls the intensity of near-infrared light emitted from the projection unit such that the determination luminance ratio is within the predetermined luminance range.