Oxide TFTs for Advanced Signal‐Processing Architectures

12.1: Invited Paper: Comprehensive solution for high image quality in medium and large‐size AMOLED displays throughout display usage cycle

“…Because of good uniformity and small hysteresis in metal oxide TFTs, an all-external compensation and simple 3T1C circuit (Figure 2a) are sufficient. By appropriately programming the pixel and biasing the readout line, drive TFT and OLED can be evaluated independently from each other [3][4][5][6]. The LTPS pixel circuit [7] (Figure 2b) supports both in-pixel compensation and external sensing.…”

“…Optical correction provides enhanced initial uniformity and can be used in combination with electrical sensing [4][5][6][7] in applications where very high image quality is required.…”

“…As previously reported, such electrical sensing and compensation scheme can also serve as a diagnostic tool for detection of manufacturing defects [8]. In addition, it can be used to generate an initial compensation data set (T0, Figure 1) and correct for image nonuniformity in the as-manufactured display panel [4,6]. Alternatively, one-time optical correction can be used for the same purpose.…”

“…A display system with external compensation for TFT and OLED degradation is best suited for such applications. Recently, data counting [1,2] and electrical sensing methods [3][4][5][6][7] have received significant attention for realization of external compensation in AMOLED display product development. The data counting method is cost effective as it requires minimum specialized hardware.…”