Technology is always on the move and several alternatives for the current LCD and Plasma panels are being intensively developed and could soon appear in our showrooms.

OLED

Stands for an Organic Light-Emitting Diode Panel and consists of an array of tiny LED dots embodied in three organic thin-film semiconductor layers on a glass substrate, sandwiched between two electrodes. When any dot is energised it generates light energy by virtue of recombination of electrons and ‘holes at the light emitting layer. The light can be red, green, blue or white depending on the doping material present at the specific spot.

Several companies are developing OLED and OLED screens, now as large as 40 inches in prototype form, have several advantages over competing systems. The screens lend themselves to very thin panels by their nature, and their absence of backlights, and offer bright high contrast pictures with good black level. They are also very energy efficient.

SED

Stands for Surface-conduction Electron-emitter and is somewhat thicker than OLED although potentially large in size. The screens have much in common with plasma screens in that they are glass faced phosphor-emissive devices. A SED panel is a few inches thick and works by the bombardment , in a vacuum of an RGB phosphor matrix by electron irradiation, not from thermionic guns via deflective fields but from a precision array of cold emitters controlled by the video signal.

SED has many of the advantages of the traditional CRT with wide viewing angle, good black level and a bright sharp image without the drawbacks of bulk, weight and high power consumption.

SXRD

This one stands for Silicon X-tal (crystal) Reflective Display which is a variant of LCD technology developed for use in front and rear projection systems. It’ main advances over conventional LCD devices are the use of a new inorganic molecular material inside the liquid crystal cells: the extreme miniaturisation of the pixels: and the minute spacing between them. The result is that a picture with extremely high definition (1920 X 1080 pixels) is easily achievable along with a high contrast ratio, and a fast response. SXRD is already in production but is currently expensive.

While these new developments remain under research or appear on the fringe of the market, established display technologies are being refined and improved. Sony has a 46 inch LCD display backlit by a bank of three-coloured LEDs. This gives a wider colour range in the display. Meanwhile Sharp has two new directional technologies in LCD screens, one that can be switched between narrow and wide angle viewing , and one that can be switched to provide different pictures for viewers to left and right of the screen.