In our newly developed display with low power consumption, circuits for a reflective liquid crystal display (LCD) and an organic light-emitting diode (OLED) display are formed in the same field-effect transistor layer to control these two types of display devices. This display has high visibility in both a bright and a dark environment with use of the reflective LCD and the OLED display, respectively.

We have successfully fabricated a 2.78-in 1058-ppi flexible OLED display. This display exhibits the highest pixel density in the world among flexible displays using thin film transistors. The display can be bent with a curvature radius R 1 mm and shows a high resistance.

We established a manufacturing process of flexible displays, adopting a transfer technology using tungsten separation layers. We performed separation with water. In this study, we describe the apparatus we built for the manufacturing process. This apparatus fabricated an 8k (7680 × 4320 effective pixels) flexible organic light-emitting diode display.

Using a WTC OLED device and a backplane using CAAC-OSFETs over a glass substrate employing the 1.5 m rule, we fabricated a 2.78-in 1058-ppi OLED display, the pixel density of which is the highest in the world among displays using thin film transistors over a glass substrate.

To improve the reliability and mechanical durability of a flexible organic light‐emitting diode display, the entire flexible display is coated with an aluminum oxide film by atomic layer deposition (ALD). Because the step coverage of ALD is excellent, the AlOx film was deposited not only on the front and back surfaces but also on the side surfaces of the display. A high‐temperature and high‐humidity preservation test, repetitive bending tests, and a pencil hardness test were conducted on the flexible display with ALD‐AlOx coating. The display survived 500 h of a 65°C, 95% preservation test, endured a 100,000‐time repetitive bending test with a curvature radius of 4 mm, and was found to have a pencil hardness of 4H.