Background
As the LCD TV market is maturing, manufacturers are seeking more ways to differentiate their product from the competition. One of the current key factors is color – to provide the viewer a colorful home cinema experience in his own living room. Therefore, wide color gamut technologies are implemented in new LCD televisions and are branded as a key selling point.
Multi-primary LCD TV advantages
Genoa Color Technologies pioneered wide-gamut displays, based on multi-primary color. Genoa’s technology implementation for LCD TV offers the best and most efficient wide-gamut solution:
- Effective color gamut increase. Genoa’s multi-primary approach allows expanding the gamut in the visually important region of yellow/gold, as well as in the cyan/turquoise region, unlike RGB-based solutions which need to compromise one or the other. For example, panels based on WG-CCFL or LED backlight increase the gamut mainly in the green/turquoise area and lack the yellow region.
- Brightness/power efficiency. A multi-primary solution has better brightness/power efficiency than any RGB-based solution. This enables a larger gamut without compromising brightness/power, and regardless of the backlight used.
- Flexibility. Using multi-primary technology brings more degrees-of-freedom into the gamut design, and allows better fit with cinematic colors. This also enables multi-primary panel to operate with any backlight, current or future.
- Cost effectiveness:
- Filters: The cost difference between a multi-primary color filter plate and an RGB one is a few percent. With the introduction of ink-jet technologies into LCD color filters production, the difference is becoming negligible.
- Backlight: Genoa’s multi-primary panel is the only solution which enables a wide-gamut and high-brightness image using standard, cheap, long-lifetime CCFL backlight.
- Scaling: The cost difference of multi-primary is not affected by the panel size (unlike, for example, LED backlight costs, which scale with panel area).
- Data format. Genoa’s multi-primary conversion algorithm can utilize the wider color gamut even when working with existing video standards to achieve the most pleasing image. In addition, the algorithm has a built-in support for future wide-gamut standards (such as xvYCC).
Implementation – pixel design
In RGB panels, each pixel consists of three sub-pixels (Red/Green/Blue), which are usually arranged in stripes. In multi-primary panels there are many different possible configurations. For each pixel, the number of sub-pixels can be less, equal or greater than the number of primary colors. In addition, the sub-pixels can be arranged spatially in a variety of ways.
When the number of sub-pixels is not equal to the number of primary colors, Genoa offers its Pixcale sub-pixel rendering algorithm to achieve the best apparent resolution.
The new sub-pixel arrangement requires the design and production of a new TFT with the appropriate electronic drivers. One unique option is to use the same TFT as RGB. In this case, the only change is the new color filter plate.
Genoa’s recommended solution is to use five primary colors (RGBCY). This configuration is optimal in terms of color gamut, brightness and white-point balance.
Implementation – algorithm
Genoa’s multi-primary conversion algorithm has to be implemented in the panel at the input. Genoa offers two alternatives for implementers:
- Keshet-LCD chip: a solution based on the KeshetTM chip which was developed for the projection market. It includes suitable interfaces for the LCD environment (LVDS) to integrate easily in the TV panels.
- IP core: Genoa’s algorithm in the form of an IP core.
Genoa also provides a full support package for calibration and image quality control.
