Seisakusho Co Ltd, a Japan-based company, was showing off an LED headlight used in Toyota's new Prius at Automotive Engineering Exposition 2009, which took place from May 20 to 22, 2009 in Japan.

The low beam headlight for the new "Prius"

The LED headlight for the new Prius is a low beam assembly which consists of a double projector unit for emitting a focused beam and a unit for emitting a diffused beam.

Trends in power consumption of LED headlights

The white LED modules used in the two units were manufactured by Nichia Kagaku Kogyo KK and consist of four elements. The modules were also used in the LED headlight of the Toyota’s "RX450h", which was released in April 2009, according to Koito Seisakusho.

Seisakusho used LED headlights for the first time in the world on Toyota's "Lexus LS600h" in May 2007, when five LED modules were needed for the headlight. Now, due to the improved LED efficiency, the number of LED modules needed for the LED headlight for the new Prius has been reduced to three.

The two headlights mounted on the new Prius are 66W, slightly more than 30% lower compared with 100W of the headlights of the LS600h, according to Koito Seisakusho.

The lower cost of the new headlight was realized from simplification of structure and less LED modules used, while is still higher than that of HID (high intensity discharge) headlights, the company said.

Koito Seisakusho expects LED headlights to be more generally used when the white LED luminance efficiency get improved and only two LED modules are required for a low beam headlight.