The creators of the blue LED, an invention which has revolutionised an industry in less than two decades, have been awarded the Nobel Prize in physics for the invention of blue LEDs.

Isamu Akasaki and Hiroshi Amano of Japan and US scientist Shuji Nakamura were announced as the winners on Tuesday by the Royal Swedish Academy of Sciences.

The academy said the invention was just 20 years old, "but it has already contributed to create white light in an entirely new manner to the benefit of us all".

The laureates triggered a transformation of lighting technology when they produced bright blue light from semiconductors in the 1990s, something scientist had struggled with for decades, the Nobel committee said.

Low-energy blue LEDs are used to create a more efficient white-light lightbulb.

"As about one fourth of world electricity consumption is used for lighting purposes, the LEDs contribute to saving the Earth's resources," the committee said.

Akasaki, 85, is a professor at Meijo and Nagoya universities. Amano, 54, is also a professor at Nagoya University, while the 60-year-old Nakamura is a professor at the University of California, Santa Barbara.

The actual Nobel Prizes are always given on December 10, the anniversary of prize founder Alfred Nobel's death in 1896. Besides the prize money of $1.1m, each laureate receives a diploma and a gold medal.

Last year's physics award went to Britain's Peter Higgs and Belgian colleague Francois Englert for helping to explain how matter formed after the Big Bang.

Source: Agencies