OLED Lighting in Japan
February 11, 2013
By Sungeun Kim and Barry Young
Nano Tech 2013 in Japan
During “Nano tech 2013” in Japan, the leading display component producers like Fujifilm and Toppan Printing demonstrated technologies that could improve the luminance of the OLED lighting, by applying the die coater process or the light extraction film, respectfully. The companies believe that the development would significantly improve OLED lighting quality, which is a priority for producers in order to in the general lighting market.
Fujifilm introduced the die coater technology, which enhances the luminance of the OLED lighting panel. The technology involves scattering organic EL materials below the OLED lighting glass panel. As a result, the process is called die coater process. Fujifilm claimed that once the panel goes through the die coater process, the light reflection rate of the panel decreases while the lighting ratio improves. Thus, the panel luminance increases by up to 40% without a light extraction layer. The company also added that the die coater technology also increases cost efficiency in OLED light production. Figure 1 shows the difference between the luminance of a panel with and without using the die coater process.
Figure 1 Fujifilm: Comparison of Two OLED Lighting Panels-Left with die coater process and Right without die coater.
Source: Fujifilm, Nikkeibp, & OLED-A
Toppan Printing introduced a new light extraction film, which also improves the OLED lighting panel performance. The company demonstrated, two OLED lighting panels made by its sister company Lumiotec) - one with its light extraction film and the other without the film. Toppan Printing’s light extraction film increases the diffusion area, thus, improving the luminance. An OLED lighting panel with a light extraction film emits over 1.4 times the brightness of a panel without Toppan’s light extraction film. In addition, the light extraction film from Toppan Printing can reduce the viewing angle dependency of the emitting light color. In general, OLED lighting color uniformity depends on viewing angle and the angular performance can be different. When the light is emitted through the various layers of an OLED panel, the output angle depends on the layer’s thickness and refractive index. Toppan Printing’s light extraction film is based on using PET film, and applying UV cured acryl resin. Figure 2 shows a comparison of the luminance with and without the enhancement film.
Figure 2 Toppan Printing-Left with Light Extraction Film, Right without Light Extraction Film.
Source: Toppan Printing, Nikkeibp, & OLED-A
Lighting Japan 2013
Lighting Japan 2013, the annual LED/OLED lighting exhibition, was held on Jan. 16-18th at Tokyo Big Sight. The exhibition had 353 exhibitors and 18,357 visitors. For next year exhibition, Lighting Japan 2014’s Reed Exhibitions Japan expects 500 exhibitors and 25,000 visitors in 2014.
According to NikkeiBP, a leading Japanese IT news source PIOL (Joint venture between Panasonic and Idemitsu Kosan,) announced its new products. The company demonstrated a variety of OLED lighting applications as shown in Figure3.
Figure 3 PIOL's OLED Lighting Application
Source: PIOL, OLED-A
One unique model was that paper screen, called shoji in Japanese, and the design drew vast attention from the attendees (picture 5). PIOL introduced panel sizes of 150 x 50 and 200 x 50, which will be released in Q1’2013. Currently, PIOL’s OLED lightings feature 3,000cd/ m2 of luminance, 30lm/W of efficacy, and 10,000 hours of lifetime @1,000 cd/m2) in 100 x 100 mm panel. In addition, the newer models, which will be launched in spring of 2013, are developed with different shape, but deliver the same specifications. , The company expects Hugh growth in the number of specifications by 2015 and 2018. The targeted specifications are up to 100 lm/W in efficacy, 5000 cd/m2 in luminance, and 20,000 hours in lifetime in 2015 while an efficacy of 130 lm/W, luminance of 5000cd/m2 and lifetime of 40,000 hours are targeted for 2018. Table 1 shows the forecast of specifications.
Table 1 PIOL Target Specifications in 2013, 2015 & 2018