Sharp Corp recently released 10 models of LED street lamps which are designed with lenses for widening the illumination area, with one of the models equipped with solar battery.

Composed of convex lenses stacked on concave lenses, the lens unit mounted on the LED chip of the new lamps serves to illuminate a wider area of a street. The concave lens has a function to horizontally widen the light (in the direction parallel to the street) while the convex lens focuses the light so that it intensively illuminates a certain area.

With the function of the lens unit, the new lamps can intensively illuminate a wider area of a street, comparing with existing LED lamps which scatter light around the spot directly under the lamp.

A wider illumination area allows the new LED lamps to be installed at greater intervals than existing lamps and the power consumption is accordingly saved substantially. Taking the solar-powered model "LN-LX1" for example, the interval of installation is as far as 32m, comparing with an interval of 12m for regular 40W mercury lamp which have a luminance equivalent to the LN-LX1. As a result, the number of lamps per kilometer can be reduced by 62%, from 84 to 32. And the electricity cost can be cut by about ¥290,000 (US$2,952) per year, according to Sharp.

The design and the production technique of the lens unit developed by Sharp Group utilized its optical design technologies which have been accumulated in the development of optical pickups, etc, and the injection molding technology based on temperature control that heats and cools molds more rapidly than normal.

Additionally, the new Sharp LED street lamps also feature a luminous efficiency improved by about 30% than Sharp's existing street lamps. The factors enabling the higher luminous efficiency remained undisclosed by the company, except for the fact that it used a package with high light extraction efficiency. With a luminance of 1,800lm, the lamps are among the brightest products in the industry, said the company.