An apparatus is described that includes a display panel and a sensor. The display panel includes an array of pixels configured to direct light through a front side of the display panel. Each pixel includes sub-pixels, each of which includes an organic light emitting diode (OLED) and an integrated circuit (IC) for controlling an electrical current to the OLED. The sensor is arranged at a back side of the display panel. The sensor includes an emitter configured to emit electromagnetic radiation transmitted through a first area of the display panel. The IC of sub-pixels of the array of pixels outside the first area includes a first IC arrangement. The IC of sub-pixels of the array of pixels within the first area includes a transistor in addition to the first IC arrangement. The transistor is configured to operate as a control switch controlling emission of light from the sub-pixel.