An OLED display panel may include a substrate, an OLED light emitter on the substrate and configured to emit light, and a visible light sensor on the substrate and configured to detect at least a portion of the emitted light based on reflection of the portion of the emitted light from a recognition target. The visible light sensor is in a non-light emitting region adjacent to the OLED light emitter so as to be horizontally aligned with the OLED light emitter in a horizontal direction extending parallel to an upper surface of the substrate, or between the substrate and a non-light emitting region adjacent to the OLED light emitter such that the visible light sensor is vertically aligned with the non-light emitting region in a vertical direction extending perpendicular to the upper surface of the substrate.