TFT-LCD module realizing plural color modes

摘要

We developed an LCD module that uses a color conversion circuit to improve imperfect color reproduction in the LCD panel. Our module implements a color conversion circuit that uses a matrix calculation we developed. This color conversion circuit supports motion picture display and real-time processing, enabling desired color conversion characteristics and facilitating use of 2 modes of color conversion characteristics by selection sRGB mode and consumer-TV-like color mode. The international sRGB standard is the default RGB color space for multimedia, in which "reference image display system characteristics" are specified, i.e., a display device must have characteristics close to sRGB characteristics to properly display color image data conforming to sRGB. This is why the sRGB specification for liquid crystal displays has been defined. Our TFT-LCD module achieves less than one tenth the color difference for the sRGB specification. Devices with low color reproducibiliry are improved using a color conversion circuit to increase apparent color depth, but conventional approaches to this have such adverse effects as color saturation in high-chroma areas and emphasized color noise in dark areas. Our module achieves consumer-TV-like color by implementing a new color conversion circuit that includes a gamut compression function to solve such problems.