AIR PURIFICATION UNITS USING NEGATIVE

Brand	Owner	Address	Description
CLEAN-ZONE	Neg-Ions (North America) Inc.	303-35 King Street Winnipeg, R3B 1H4, Manitoba Canada	air purification units using negative ionization for commercial, industrial and domestic use;
	Where the owner name is not linked, that owner no longer owns the brand

Technical Examples

A zoom lens system includes four lens units having, from an object to an image side, negative, positive, negative and positive optical powers, respectively. During zooming, the intervals between the first and second lens units, and also the third and fourth lens units at the telephoto end are smaller than that at the wide angle end. Also, an interval the second and third lens units at the telephoto end is larger than that at the wide angle end. A zoom ratio is about 2.5 to 4.0. The following condition is satisfied: 2.2<bfw/H<3.0, where bfw represents a back focus at the wide angle end, and H represents a maximum image height.