Hitachi Consumer Electronics Co Ltd developed front projectors featuring small size, light weight and short focal length.
The company announced two types of projectors, the "direct projection type," which projects images directly from the lens, and the "fold-up mirror type," which uses a reflecting mirror to further shorten the focal length. In September 2007, it developed a short focus projector that can project a 60-inch image from a distance (between the reflecting mirror and the screen) of 42cm.
This time, Hitachi Consumer Electronics aimed at developing a projector that has not only a short focal length but also a smaller size and a lighter weight for use in offices, schools and so forth. The new projectors can easily be installed on a ceiling because of their small size and light weight, the company said.
The direct projection type measures 333 x 124 x 303mm and weighs 3.5kg, while the fold-up mirror type measures 333 x 135 x 303mm and weighs 4.7kg. The dimensions and the weight of the company's previous product are 397 x 131 x 356mm and 5.8kg, respectively.
When a 60-inch image is projected, the distance between the lens (or mirror) and the screen is 68cm for the direct projection type and 59cm for the fold-up mirror type, which are a little longer than that of the previous product.
To realize a small size and light weight at the same time, Hitachi Consumer Electronics redesigned the optical system. The direct projection type uses 17 lenses, and its optical system is 190mm in length. The fold-up mirror type comes with a reflecting mirror in addition to the 17 lenses. And semicircular lenses called "half-cut lens" are used in the front part of the projectors to reduce the size and weight.
The optical system of the previous product is mounted with a free-form surface mirror and a free-form surface lens so that trapezium distortion and focal length distortion are reduced. Though the previous product has only 10 lenses and one reflecting mirror, its optical system is as long as 328mm.
The direct projection type will be released in the European and the US markets in October 2009. Its pixel count, luminance and contrast ratio are 1,024 x 768, 2,000lm and 400:1, respectively. There is no manufacturer's suggested retail price. Hitachi Consumer Electronics is considering launching the projector in Japan, too.
The new projectors will be exhibited at CEATEC JAPAN 2009, which will run from Oct 6 to 10, 2009, at Makuhari Messe in Chiba Prefecture, Japan.