Touch‐screen panel integrated into 12.1‐in. a‐Si:H TFT‐LCD

Abstract

Abstract— A touch‐screen‐panel (TSP) embedded 12.1‐in. LCD employing a standard existing a‐Si:H TFT‐LCD process has been successfully developed. Compared with conventional external touch‐screen panels, which use additional components to detect touch events, the new internal TSP exhibits a clearer image and improved touch feeling, as well as increased sensing speed using discrete sensing lines to enable higher‐speed sensing functions including handwriting. The new internal digital switching TSP can be fabricated with low cost because it does not require any additional process steps compared to a standard a‐Si:H TFT‐LCD.

Novel fabrication techniques for ultra-thin silicon based flexible electronics

“…Because of these advantages, a-Si:H efficiently absorbs light and can be used in optoelectronic devices such as solar cells. Additionally, its applications extend to touch-screen panels like e-books where high scanning rates are not critical [117,118].…”

Active Matrix Touch Sensor Perceiving Liquid Crystal Capacitance with Amorphous Silicon Thin Film Transistors

“…Recently, technologies for touch sensor integration on the substrates of thin-film transistors (TFTs) in liquid crystal displays have been proposed. [1][2][3][4][5][6] They have many advantages such as reduced production cost for touch screens, light weight, and good display quality over add-on-type touch screens. Three kinds of sensors for in-cell touch panels, namely, resistive, capacitive, and optical sensors are being considered.…”

“…Another approach for in-cell touch panels is the use of a resistive sensor, which is composed of two electrodes made on a TFT and a color filter substrate. 4,5) These two electrodes are electrically shorted when external force is applied, so that it is immune from external light but requires a high activation force to work the sensor. A capacitive touch sensor uses the capacitance variation of liquid crystals when a touch event occurs.…”