Panasonic launched the standard-size E26 LED bulb and the compact-size E17 LED bulb last fall. The E17 bulb is designed to replace compact bulbs such as mini-kryptons. Conventional fluorescent light bulbs had been too large to serve as replacements for these bulbs.
Because an LED's luminous efficiency rises as temperature falls, it is important to keep the LED package cool. By applying alumite treatment to the container surface, Panasonic successfully boosted heat dissipation to lower the temperature of the LED package. This plus the tight connection between the LED package and the casing gives the industry's highest energy efficiency in LED bulbs, Panasonic claims.
When used as a downlight, the 6.9-W standard LED bulbs deliver the brightness equivalent of 60 W incandescent bulbs. The 4.0-W standard and 5.5-W compact LED bulbs produce output comparable to 40 W incandescents. The 7.6-W standard LED bulbs have the brightness of 60 W incandescents when used as downlights.
Panasonic also says the bulbs are the lightest in the industry thanks to their use of a thinner casing that uses less aluminum. The standard size E26 base bulb weighs only 100 g and the compact size E17 base bulb weighs 50 g.
The 7.6 W standard type and the 5.5 W compact type LED bulbs are dimmable from 10 to 100%.
More info: http://panasonic.co.jp/corp/news/official.data/data.dir/en090910-3/en090910-3.html