Kohzoh Nakamura

29.2: Power‐Saving: A New Advantage of Multi‐Primary Color Displays Derived by Numerical Analysis

In this paper, we present the advantages of Multi-Primary Color (MPC) display devices compared to the conventional display devices with three (red, green, and blue) primary colors. Not only do we review the well-known advantages such as wide color gamut and wide viewing angles but also introduce the examples of numerical computation for the purposes of the luminance reproduction. According to the results, we also estimate the potentials of power-saving for RGB, RGB + Yellow, and RGB + White systems. It is shown that MPC systems are much superior to RGB-based systems in terms of power-saving. Not only does RGB + Yellow system widens color gamut but also reduces power consumption by 20% with respect to RGB-based systems.

P‐69: Beyond RGB‐Primaries: Chromaticity Measurement Issues for Multi‐Primary Displays

The current standards of color gamut measurement regarding RGB-primary displays are not applicable to multi-primary color (MPC) display systems. We show two case studies that measurement performed by simply extending the use of todays RGB-based standards is not able to provide accurate evaluation of the color gamut of MPC displays. The color gamut of MPC displays depends on signal processing algorithm; therefore, for measuring the color gamut of MPC displays, we propose to use not only the input signals of the maximum values for respective colors but also medium-level signals which are able to measure the chromaticity of respective primary color points on MPC display.

Multi‐primary‐color LCD: Its characteristics and extended applications

— The development of multi-primary-color (MPC) display systems is one of the big paradigm shifts in recent display technologies and induces new potentials of display devices. The development of MPC display systems for different goals is briefly reviewed. Especially, by employing MPC systems, it is possible to reproduce the real material colors faithfully and efficiently. For signal processing, MPC systems have a big advantage in the so-called color-reproduction redundancy. A number of applications can be derived from this characteristic, such as improving the viewing-angle dependency issue and power savings. On the other hand, MPC systems have a typical trade-off versus RGB-standardized input signals, especially for reproducing bright green. New algorithms to moderate this trade-off on MPC systems by employing color-reproduction redundancy are proposed. The goal of our algorithms is to maintain the compatibility with RGB-based input signals though the initial display design so that the characteristics of MPC systems are not changed or lost. These algorithms indicate that MPC display systems are applicable not only for a specifically limited objective but also for other applications, e.g., TV broadcasting.

QuintPixel: multi-primary color display systems

Todays conventional Liquid Crystal Displays (LCD) are assembled with three primary colors (red, green, and blue: RGB). Further, the most common color gamut standards are defined in RGB-primary colors. Such a system lacks the capability to reproduce all of the real-surface colors; for example, sRGB cannot cover Pointers real-surface color dataset which consists of the measurement over the existing colors in the world except self-luminous objects [Pointer 1980] at most of the hue angles (see Figure 1 right). However, recent developments on display devices have made it possible to have wider color gamut than before. However, as long as there are only three primary colors, such display system still cannot cover the real surface colors efficiently. An example of relatively wide gamut (DCI 2005) in Figure 1 still shows poor coverage ratio against Pointers dataset.