The display device has a sensor system with at least one sensor for detecting the intensity or color of light emitted from at least one display area of the display device into the viewing angle of the display device. The sensor system further has in one embodiment an at least partially transparent sensor. The sensor system has in another embodiment at least one optical coupling device including a light guide member and a incoupling member for guiding or directing, e.g. deflecting, reflecting, bending, scattering, diffracting, at least one part of the light emitted from the display area to the corresponding sensor, where the sensor is located outside or at least partially outside the viewing angle of the display device.