BMW has a patented addition to rearview cameras in Europe. Namely, projectors that will transmit information to the side windows of cars.
The BMW patent provides for the installation of rear-view cameras instead of traditional mirrors, but instead of showing the image on screens in the cabin, it is proposed to project the video stream along with the semi-mirror parts of the side windows. The driver will feel that the virtual image is 0.5 – 2 meters away from him, similar to how head-up displays on windshields work. Despite the fact that the cameras will probably be installed on “legs” outside the car, the projectors themselves are supposed to be mounted in the cabin.
The authors of the developers expect that such a system will receive a number of advantages over traditional side mirrors and existing systems of “virtual mirrors” with displays. First of all, there is again in aerodynamics due to a decrease in drag, since cameras are much more compact than mirrors with a greater angle of coverage. In addition, it will be easier for the driver to focus at a greater distance, shifting his gaze from the road and back, therefore, the person behind the wheel will be less tired.
Another advantage highlighted in the patent is the ability to overlay payloads on virtual mirrors. These can include anything from navigation instructions to parking alerts and even distances to nearby vehicles for safer lane changes. However, this is not unique to BMW technology and can be applied to any other virtual mirror system using conventional screens.
A natural question arises – what to do when the windows are hidden for ventilation? For such cases, German engineers have provided fixed parts of the glazing in the front doors, so that the semi-mirror elements will always remain in sight. It is also assumed that the reflectivity of the mirror portion should be variable. This will allow the brightness of the virtual mirrors to be adjusted according to the ambient light conditions so that they are visible during the day but not too bright at night.
As noted by The Drive, one of the disadvantages of virtual mirror systems is the fixed field of view. Unlike traditional mirrors, their virtual display alternatives cannot respond when the user moves their head, since the camera is fixed regardless of the position of the driver’s head. This can be corrected with head tracking, an already mature technology used in fighter jets and virtual reality devices. In the end, drivers can simply adjust to using a fixed side-view camera if it provides a large enough field of view.
It is not yet known whether the patent-pending development will actually work on production cars.