71‐2: Novel Optical Image Sensor Array Using LTPS‐TFT Backplane Technology as Fingerprint Recognition

Abstract

A novel photo sensor by LTPS TFT backplane technology is developed, which amorphous silicon (a‐Si) layer stacks on poly silicon (p‐Si) layer to form a vertical hybrid poly and amorphous silicon PIN photo diode (HPAS‐PIN). This photo diode shows good photosensitivity as traditional a‐Si photo sensor. An optical fingerprint sensor array is realized based on the novel HPAS‐PIN photo diode and successfully capturing fingerprint image.

42‐4: LTPS TFT‐LCD with In‐cell Optical Fingerprint Scanner

“…As showed at figured 1(a), the EQE is improved across all visible wavelengths after defect state control, and the significantly improves at short wavelengths is credited to thinner positive layer. With all process optimization, total EQE of LTPS photo sensor is double more than our early report [2]. Figure 1(b) also shows the reverse I-V curve of LTPS photo sensor exposed by 680nm light source, dark leakage current is less than 0.5nA/mm 2 at -3V bias.…”

“…We also designed a LTPS image sensor array driven by above mentioned APS circuit and covered by a 0.15mm thin glass, then put finger on the surface of glass to capture fingerprint image, as showed at figure 3. Compared with image captured by our early reported PPS type LIS array [2], image captured by this APS type LIS array is much clear, as APS type LIS has higher sensitivity and strong anti-jam capability. We also designed a LTPS image sensor array driven by above mentioned APS circuit and covered by a 0.15mm thin glass, then put finger on the surface of glass to capture fingerprint image, as showed at figure 3.…”

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].…”

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].…”