50.1: Invited Paper: Technological Progress of Panel Design and Compensation Methods for Large‐Size UHD OLED TVs

Abstract

The world's first 77-inch UHD OLED TV with an excellent image quality has been developed, using an IGZO TFT backplane and white OLEDs with an RGBW pixel structure and a novel compensation method applied to the panel. In this paper, we discuss technical issues and challenges in panel design and driving methods to compensate the non-uniformity of oxide TFTs, OLED devices, colors, and luminance, including our recent technologies that have realized a panel size scalability and a product reliability for commercializing large-size OLED TVs.

Bezel free design of organic light emitting diode display via a‐InGaZnO gate driver circuit integration within active array

“…As we mentioned before, because the coupling between the integrated gate driver node and emission circuit node can result in luminance difference, we have to check the luminance uniformity of the GIA designed panel. To remove the difference resulted from the TFTs, we have compensated its threshold voltage by an external sensing method equal to OLED TVs . And then, we measured over nine spots of the display from low gray to full white.…”

Advanced compensation technologies for large‐sized UHD OLED TVs

“…We use WOLED with a broad spectrum and color layers for red, green, and blue subpixels, which is the technologically and economically best choice for large‐sized OLED displays because the WOLED deposition process uses an open mask instead of a fine metal mask, and we use an existing process to form color layers on the substrate . Figure shows a comparison between RGB and RGBW structures.…”

“…We announced the world's first 77‐in. ultra‐high‐definition (UHD) (3840 × 2160) OLED TV in 2014, and 55‐ and 65‐in. UHD OLED TVs in 2015 …”

Integrated gate driver circuit technology with IGZO TFT for sensing operation

“…In this paper, we introduced novel GIP circuit to realize the real time sensing and compensation process of OLED TVs. The external compensation method (ECM) compensates for the threshold voltage and mobility variation of TFTs . Using this method, we solve reliability issues caused by positive and negative biases, temperature, and current stress.…”

“…The external compensation method (ECM) compensates for the threshold voltage and mobility variation of TFTs. [2][3][4][5] Using this method, we solve reliability issues caused by positive and negative biases, temperature, and current stress. This ECM requires proper sensing technology.…”