Fineness of a display is expressed by pixel density (ppi = pixels per inch). On a high pixel density (= high definition) display, the pixels constituting the display are not recognizable. Therefore, images look clear and characters look smooth.
Comparison of picture quality (example)
Japanese font "shueitai"
TFTs (= thin film transistors) used in a TFT LCD are made of silicon as semiconductor material. It is, however, very difficult to fabricate crystaline silicon onto glass, and only amorphous silicon (a-Si) could be fabricated in the past. Since electron’s mobility in a-Si is low to drive TFT fast, there are limitations to pixel density of displays.
In contrast, a low temperature poly-silicon (LTPS) TFT LCD, prepared by forming polycrystalline silicon on a glass substrate at relatively low temperatures, achieves high carrier mobility in TFT. Therefore, LTPS TFT LCD realizes a high resolution and high density display that cannot be achieved with a-Si by integrating part of the display drive circuitry on the glass substrate. JDI has developed LTPS displays, and has introduced one of the world’s highest density display prototypes.Prototype of 651ppi high definition display
|Screen size||2.3-inch (5.9cm) diagonal|
|Number of pixels||1280×800 (WXGA)|
|Number of colors||16,777,216 colors|
Closeup of display image