Novel Micro-LED Display Featuring Fingerprint Recognition Without Additional Sensors

This paper proposes a new architecture for micro light emitting diode (micro-LED) display featuring fingerprint detection without any additional and sensing devices in mobile applications. that conventional LEDs can be used as photodetectors active-matrix pixel circuits. In the area where finger touched, some are others sources. The photocurrents of reverse-biased under various illumination conditions were investigated. circuit was fabricated using p-type low-temperature polycrystalline silicon (LTPS) process. could distinguish intensity incident to LED. voltage across LED (VLED) investigated when density 400 pixels per inch (ppi) cover glass thickness 30 μm. experimental results showed VLED changed by 0.5 V 16.7 ms red, green, or blue emitted 150 cd/m2, 100 respectively. 1×9 array with 1.5 mm pitch (p) 2 thick emulate ppi μm glass. It is found an affected within distance 3p comparing VLEDs. VLEDs measured material on air water white pigments (water/W). ΔVLEDs 0.29 1.13 glass-air glass-water/W cases, lights comprised not only reflected Fresnel reflection at interface but also scattered water/W. A 75× magnified fake fabricated. Its poly-lactic acid refractive index 1.465 which very close fingertip. Measured ridges valleys 0.48 0.22 V, ratio / 2.18 1.91 ridge valley obtained calculation. verifies proposed micro-LED distinguishes help from devices.