Ricoh Company, Ltd.

Stanley Electric Co., Ltd

Teiichiro Takano

Nobutaka Takeuchi

Ichiro Kadota

Takashi Hodoshima

An LED lighting unit can be configured to have a high color rendering for which color temperature can adjust itself to be close to a natural color. The LED lighting unit can be composed of three light sources that respectively include a blue LED and a different phosphor. A first light source can emit light having a color temperature located substantially on a blackbody locus, a second light source can emit light having a higher color temperature than that of the first light source and located substantially on the blackbody locus, and a third light source can emit a green or yellow light. A mixture of the light can be located substantially on the blackbody locus by controlling a beam ratio of the mixed light having contiguous wavelength components. Therefore, the LED lighting unit can emit a light having a high color rendering that can maintain a uniform color within a radiation range.

LED lighting unit with LEDs and phosphor materials

A developing method of the present invention uses a sleeve accommodating a stationary magnet roller formed with a plurality of magnetic poles and facing an image carrier. The sleeve is rotated to convey a developer, which is made up of toner grains and magnetic carrier grains and deposited on the sleeve, to a developing zone for thereby feeding the toner grains from a magnet brush formed by the developer to a latent image formed on the image carrier. When the developing zone is seen from the image carrier side, the ratio of the total area of voids present at the tips of the magnet brush to the total area of the developing zone is selected to be 25% or less.

Growing community of inventors

Tokyo, Japan

Teiichiro Takano