Variable Transmission Screen for Nighttime Driving Assistance
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Solution Overview
Problem
Existing solutions for reducing dazzling from oncoming vehicles' headlights often impair the driver's perception of the road scene, either by obscuring necessary elements or having slow response times and low effectiveness, particularly when the issue is caused by misadjusted or dirty headlights or heavy vehicles with elevated headlamps.
Innovation Solution
A device with a variable transmission screen controlled in synchronism with the vehicle's headlights, using Pulse Width Modulation to adjust illumination and transparency, allowing maximum visibility of passive and semi-active elements while reducing active light sources' intensity without affecting the overall road scene perception.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a variable transmission screen is used to reduce dazzling from oncoming vehicles, then the driver's visibility of active light sources is improved, but the perception of passive and semi-active road scene elements deteriorates
Solution Approach 1:
The patent applies periodic action by synchronizing the dimming of the variable transmission screen with the illumination cycles of the vehicle's headlights. The screen dims periodically when the headlights illuminate passive and semi-active elements, and returns to normal transmission when the headlights are off, allowing the driver to see both reduced dazzling from active light sources and enhanced visibility of passive/semi-active road elements at different times
Solution Approach 2:
The patent uses preliminary action by pre-dimming the variable transmission screen before the headlights illuminate passive and semi-active elements, and pre-restoring its transmission after illumination. This timing ensures that when passive and semi-active elements are illuminated, the screen is already in the dimmed state to maximize their visibility while minimizing glare from active light sources
2Object-affected harmful factors
If polarizing filters are installed on lighting devices and worn by drivers, then dazzling from oncoming vehicles is reduced, but the complexity and cost of the system increases significantly
Solution Approach 1:
The patent extracts the anti-dazzle function from the complex polarizing filter system and implements it through a simpler variable transmission screen controlled by the vehicle's existing headlight illumination cycles. This eliminates the need for polarizing filters on both vehicles and drivers, reducing system complexity while maintaining the anti-dazzle effect
Solution Approach 2:
The patent applies self-service by using the vehicle's own headlight illumination cycles to control the variable transmission screen, eliminating the need for external polarizing filters on other vehicles. The system uses its internal headlight timing signals to automatically adjust the screen transmission, making the anti-dazzle function self-contained and independent of other vehicles' equipment
3Object-affected harmful factors
If the variable transmission screen is dimmed to reduce dazzling, then the intensity of active light sources is reduced, but the overall visibility of the road scene deteriorates
Solution Approach 1:
The patent applies periodic action by cycling the variable transmission screen between dimmed and normal transmission states in synchronization with the headlight illumination cycles. During the dimmed phase, active light source intensity is reduced to minimize dazzling. During the normal transmission phase, full road scene visibility is restored. This periodic switching maintains both anti-dazzle protection and overall visibility over time
Solution Approach 2:
The patent uses preliminary action by restoring the screen's transmission to normal levels after the headlights have illuminated passive and semi-active elements. This ensures that when the headlights are off and the road scene needs maximum visibility, the screen is already in the normal transmission state, preventing any loss of overall road scene visibility
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
The solution provides optimal road scene visibility with reduced dazzling from active light sources, maintaining the perception of passive and semi-active elements and enhancing safety by synchronizing light source power and screen transparency, ensuring continuous and clear visibility of important road elements.
Implementation Method 1
using Pulse Width Modulation to adjust illumination and transparency
Implementation Method 2
the illumination emitted by the lighting device being variable between a maximum value and a minimum value
Data Source
Figure 1~2
Figure 3~4B
Figure 5~6C
AI summary
The invention relates a nighttime driving assistance device for a motor vehicle (20), said vehicle (20) being provided with at least one lighting device (22) for emitting a regulatory light beam (42) that illuminates the road scene (S) in front of the vehicle (20) and the illumination (E) emitted by the lighting device (22) being periodically variable between a maximum value (EMAX) and a minimum value (Emin). The device comprises at least one variable transmission screen (26, F, 28) arranged between the road scene (S) and the driver (24) of the vehicle (20), the transmission coefficient (CT) of the screen (26, F, 28) being periodically variable between a maximum value (CTMAX) and a minimum value (CTmin). The switching on of at least one light source of the lighting device (22) and the transmission coefficient (CT) of the variable transmission screen are controlled synchronously by the same central control module (30), the illumination (E) reaching its maximum value (EMAX) substantially when the transmission coefficient (CT) of the screen (26, F, 28) reaches the maximum value (CTMAX) thereof. According to the invention, the central control module (30) controls a power management circuit (32) of the light source of the lighting device (22) and a transmitter (38) that transmits remote control waves (OT) to a receiver (40). The invention is suitable for motor vehicles.