CEATEC JAPAN 2015

Mitsubishi Electric exhibited RGB laser backlight technology in its booth at CEATEC JAPAN 2015.

Technology exhibit on the RGB laser backlight. The display adopted by the company is on the right

This technology was developed jointly with the Japan Broadcasting Corporation (NHK) in response to the institution’s request. The technology was also presented at NHK Open House 2015, where it gained a lot of attention.

According to BT.2020 image specifications for 4K8K broadcasting, the color gamut is set wider than it is now. However, TVs that can faithfully reproduce this wide-color range never existed. This is why the RGB laser backlight technology was adopted for this Mitsubishi Electric-NHK joint development. Red, blue and green semiconductor lasers are positioned the left and right sides of the screen, and rod-shaped transparent material converts the laser light into line light source. Additionally by arranging the 3 colors in sequence and adjusting the 3 wavelengths, surface light source in white is produced.

Although LED technology has a wide wavelength and bandwidth, color purity degradation has always been a problem. Conversely, Mitsubishi Electric has been using red semiconductor lasers for the backlights of its LCD TVs. The exhibit this year is an application of this technology. In particular, since high output green lasers are only a recent development, the display in this exhibit could be the first to use them to produce LCD backlight.

The Mitsubishi Electric booth at CEATEC JAPAN 2015

The booth featured a comparison with a conventional device, and it was immediately clear that the RGB laser backlight system produced images with higher color saturation. To faithfully reproduce images from signals, the system on exhibit did not use any color adjustment devices such as an image engine. This was an excellent example of what the BT.2020 display standards can offer in showing images beautifully without any of such compensation.

However, because these semiconductor lasers are an expensive technology, it will take some time before the technology becomes available at the consumer level. The company plans to first of all make a product available for video production companies in time for the 4K8K trial broadcasts next year.