38.2: Invited Paper: A New Full Screen Flexible AMOLED Solution with Fingerprint

Abstract

A mapis matrix has been integrated in the back plane of flexible AMOLED to form a high performance light path for the fingerprint sensor. Mapis fingerprint shows reasonable optical image properties and reliabilities.

P‐1.10: Photodiode‐Gated Thin‐Film Transistor Enabling Under‐Display Fingerprint Sensing Application

“…The first one is the light intensity of the OLED screen surface which need to be measured from the OLED smart phone screen. The second parameter is the reflectance of the finger skin which is 4%-7% [3] and the final one is the transmittance of the OLED display module which is 3% [2].…”

“…where V TH0 is the original threshold voltage of the dual-gate TFT at zero photodiode bias without illumination, γ is the parameter that dictates the top gate controllability over the threshold voltage. V TG0 is the top gate voltage at a fixed photodetector bias without illumination, and is a function of the anode voltage (V Bias ), the MIS photodiode capacitance (C MIS ), and the top gateinsulator-semiconductor capacitance of the dual-gate LTPS TFT (C TOP ), which can be described as follows: (2) and ΔV TG , the photo-induced voltage on the top gate, is a function of photogenerated charges Q e and C TOP:…”

“…A conventional amorphous silicon PIN photodiode is used for optical sensing and an amorphous silicon TFT acts as a switch in a passive pixel sensor (PPS) array to enable fingerprint imaging for AMOLEDs. In order to allow finger-reflected light to reach the optical sensor accurately and efficiently, either a thick collimator or a mapis matrix was used [1,2]. However, these two approaches undoubtedly increase the manufacturing complexity and cost.…”

7.4: Investigation of Moiré Interference in Pinhole Matrix Fingerprint on Display Technology

“…Fingerprint on display (FOD) technology has become an essential function of high end OLED mobile phones [1][2][3][4]. Apart from the collimator and lens type optical FOD that are already available on the market, there has been some interest amongst panel makers in developing an alternative solution based on pinhole matrix imaging [2]. Some previous reports and attempts have demonstrated the superior image quality and compactness of this type of FOD, largely thanks to the high resolution of pinhole imaging.…”

28‐4: Investigation of Moiré Interference in Pinhole Matrix Fingerprint on Display Technology

“…Fingerprint on display (FOD) technology has become an essential function of high end OLED mobile phones [1][2][3][4]. Apart from the collimator and lens type optical FOD that are already available on the market, there has been some interest amongst panel makers in developing an alternative solution based on pinhole matrix imaging [2]. Some previous reports and attempts have demonstrated the superior image quality and compactness of this type of FOD, largely thanks to the high resolution of pinhole imaging.…”