Ferroelectric Liquid Crystal Displays with Greyscale 

Having presented a range of powerful FLC display prototypes (among them a 24' monochrome, a 21' colour and several different 15' screens) Canon Inc. in Tokyo is now manufacturing their first commercial FLC product. It is a colour panel with 15' (38 cm) diagonal with a resolution of 1240 1024 picture elements. Each such element (230 pm 230 pm) can produce 16 different colours due to its subdivision in four parts. When writing a picture a large number of hues can be simulated (32000 or 26000 are stated for the two different versions marketed) by a graphic so-called error diffusion technique. In general this gives a very good rendition of colour images but in certain cases the differently coloured single dots, which can be seen when the observer is very close to the screen, may be disturbing. The origin of this inconvenience is of course the fact that each subpixel only has two states; it cannot produce a continuous grey scale.