In the late 1990s, the Hong Kong Polytechnic University and Tsinghua University took the lead in the pioneering research of fingerprint identification technology. Fingerprint identification has advantages such as high accuracy, fast speed, low price and high user acceptability, so it has attracted full academic attention since it was pioneered. Universities and research institutions both domestic and abroad have joined in this research field and made a series of achievements.
At present, fingerprint identification functions are incorporated into more and more display products. The structure of such a display product is usually implemented by adding a control transistor and a photosensitive element (such as a photoresistance or photosensitive diode) to a display pixel. That is, the control transistor controls the photosensitivity of the photosensitive element to achieve identification of fingerprints.
However, according to an existing control scheme for the photosensitive element, the control transistor is usually controlled individually. For example, scan lines for the control transistor are arranged separately and the control transistor is controlled individually by scanning. Meanwhile, transistors and scan lines used for displaying function in the display product are arranged separately for controlling normal display of pixels in the display product.
However, with such design of fingerprint identification, image display and fingerprint identification cannot be carried out synchronously. In other words, a fingerprint cannot be identified when a display image is viewed, and a special scan time for fingerprint identification is required. In actual applications such as fingerprint unlocking and fingerprint identification payment in which a screen or a payment interface is triggered by fingerprints, the fingerprint identification functions cannot be achieved with the image displayed normally, which leads to great inconvenience in the actual applications.