Rearview Mirror Assembly With Adaptive Full-Screen Video and Glare Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional interior rearview mirror assemblies lack the ability to provide a comprehensive rearward view while minimizing glare and enhancing image visibility during both daytime and nighttime driving conditions, especially when sunlight or headlights interfere with the display of video images.
Innovation Solution
An interior rearview mirror assembly featuring a transflective electro-optic mirror reflective element with a display device behind it, utilizing an LCD panel with an LED backlight that adjusts illumination intensity based on driving conditions and independently controls backlight zones to optimize image visibility, and incorporates a heatsink for thermal management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If a display device is placed behind the mirror reflective element, then video images can be displayed for rearward viewing, but glare from sunlight or headlights interferes with image visibility
Solution Approach 1:
The mirror assembly dynamically switches between reflective mode (for traditional rearview) and display mode (for video images) based on driving conditions. The display device is selectively activated and the electro-optic element changes its optical properties to either reflect ambient light or transmit display light, resolving the glare interference problem by making the system adaptive rather than static
Solution Approach 2:
The electro-optic element changes its optical parameters (reflectivity vs. transmissivity) based on the operational mode. When displaying video images, the electro-optic element transitions to a state that allows light from the display device to pass through while blocking reflected glare, thereby improving image visibility under various lighting conditions
2Illumination intensity
If LED backlight illumination intensity is increased, then video image visibility is improved, but power consumption increases
Solution Approach 1:
The LED backlight illumination intensity is dynamically adjusted based on ambient lighting conditions and the specific viewing requirements. The system uses sensors to detect ambient light levels and automatically modulates the backlight intensity to provide sufficient image visibility while minimizing power consumption, avoiding constant high-intensity illumination
Solution Approach 2:
The illumination parameters of the LED backlight are changed based on operational conditions. The system varies brightness levels, pulse width modulation duty cycles, and activation timing to optimize the balance between image visibility and power consumption, using higher intensity only when necessary for image display
3Area of stationary object
If the display screen spans the full height and width of the mirror reflective element, then viewing coverage is maximized, but heat generation from the display device increases
Solution Approach 1:
The display system is segmented into multiple independent LED backlight zones that can be controlled separately. This allows the system to activate only the necessary portions of the display based on viewing requirements, reducing overall heat generation while maintaining adequate illumination of the display area
Solution Approach 2:
Different zones of the display have independent illumination control, allowing localized adjustment of brightness and power consumption. The system can illuminate specific regions of the display screen based on ambient conditions and viewing needs, rather than uniformly illuminating the entire area, thereby reducing total heat generation
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 enhances the visibility of video images by dynamically adjusting illumination and reducing glare, ensuring clear rearward viewing during various lighting conditions while maintaining efficient power usage and minimizing heat generation.
Implementation Method 1
the mirror reflector reflects light that is incident on the electro-optic element and partially transmits illumination emitted from the display device through the electro-optic mirror reflective element
Implementation Method 2
an LCD panel that has an LED backlight
Data Source
AI summary
A vehicular dual-state interior rearview mirror assembly includes a mirror head including an electrochromic mirror reflective element having a transflective mirror reflector. A video display device occupies at least 75 percent of the viewable reflective region of the mirror reflective element. With the mirror assembly operating in a first state, the video display device does not display video images and the driver views rearward via reflection at the viewable reflective region and, with the mirror assembly operating in a second state, the video display device displays video images for viewing at the viewable reflective region by the driver. When operating in a daytime mode, the display screen utilizes red pixels, green pixels, blue pixels and clear pixels of the display screen, and when operating in a nighttime mode, the display screen utilizes red pixels, green pixels and blue pixels and does not utilize clear pixels.