Research and Development

Tomoyuki Nakayama, Kunimasa Hiyama, Keiichi Furukawa, and Hirofumi Ohtani
Konica Minolta Technology Center, Inc., Display Technology R&D Laboratories,

For light sources, especially illumination light sources, color stability while driving a device is an important characteristic and lowering a color change as much as possible is demanded generally.

As a result of an effort to suppress a color change while driving a device by optimizing the emission layers design, the color change in the Lifetime period in which luminance becomes half of the initial value was under Δ E 0.03, where Δ E=√(x²+y²) and x, y are CIE1931 color coordinates.