Nichia Corporation

Masaki Kondo

Kazushige Fujio

Shozo Taketomi

Hirofumi Ooguri

Yasuaki Mashima

Hirofumi Oguri

Seigo Sunagawa

Takafumi Sumie

A method for producing a rare earth aluminate sintered body includes: preparing a molded body by mixing a fluorescent material having a composition of a rare earth aluminate and a raw material mixture comprising an oxide containing at least one rare earth element Ln selected from the group consisting of Y, La, Lu, Gd, and Tb, an oxide containing Ce, an oxide containing Al, and optionally an oxide containing at least one element Mselected from the group consisting of Ga and Sc; and calcining the molded body to obtain a sintered body.

Method for producing rare earth aluminate sintered body

A light-emitting device is provided. The light-emitting device includes a light-emitting element having a peak light-emitting wavelength in the range of 440 nm to 470 nm, and a fluorescent member. The fluorescent member includes a first fluorescent material having a peak light-emitting wavelength in the range of 480 nm to less than 520 nm, a second fluorescent material having a peak light-emitting wavelength in the range of 520 nm to less than 600 nm, and a third fluorescent material having a peak light-emitting wavelength in the range of 600 nm to 670 nm. The light-emitting device has a ratio of an effective radiant intensity for melatonin secretion suppression to an effective radiant intensity for blue-light retinal damage of 1.53 to 1.70 when the light-emitting device emits light with a correlated color temperature of 2700 K to less than 3500 K; 1.40 to 1.70 when the light-emitting device emits light with a correlated color temperature of 3500 K to less than 4500 K; 1.40 to 1.70 when the light-emitting device emits light with a correlated color temperature of 4500 K to less than 5700 K; and 1.35 to 1.65 when the light-emitting device emits light with a correlated color temperature of 5700 K to 7200 K.

Light-emitting device

Provided is a ceramic complex having high luminous characteristics. Proposed is a ceramic complex including a rare earth aluminate fluorescent material, glass, and calcium fluoride, wherein, when the total amount of the rare earth aluminate fluorescent material, the glass, and the calcium fluoride is taken as 100% by volume, the content of the rare earth aluminate fluorescent material is in a range of 15% by volume or more and 60% by volume or less, the content of the glass is in a range of 3% by volume or more and 84% by volume or less, and the content of the calcium fluoride is in a range of 1% by volume or more and 60% by volume of less.

Ceramic complex, light emitting device using the same, and method for producing ceramic complex

A ceramic complex that has improved optical characteristics including luminous efficiency is provided. A method for producing a ceramic complex, including: preparing a molded body containing rare earth aluminum garnet fluorescent material, aluminum oxide, and lutetium oxide, and having a content of the rare earth aluminum garnet fluorescent material in a range of 15% by mass or more and 50% by mass or less, and a content of the lutetium oxide in a range of 0.2% by mass or more and 4.5% by mass or less, based on the total amount of the rare earth aluminum garnet fluorescent material, the aluminum oxide, and the lutetium oxide; and calcining the molded body in an air atmosphere to provide a ceramic complex having a relative density in a range of 90% or more and less than 100%.

Ceramic complex light emitting device using the same, and method for producing ceramic complex

A method for producing a fluorescent material is provided. The method includes preparing fluorescent material particles that contain an alkaline earth metal aluminate having a composition represented by (Sr,Eu)AlO, where x satisfies 0.05&#x2264;x&#x2264;0.4, and a part of Sr may be substituted by at least one element selected from the group consisting of Mg, Ca, Ba, and Zn; causing the prepared fluorescent material particles to come into contact with a liquid medium containing water; removing at least a portion of the contacted liquid medium to obtain purified fluorescent material particles; causing a phosphate compound to adhere to surfaces of the purified fluorescent material particles to obtain fluorescent material particles to which the phosphate compound is adhered; and heat treating the fluorescent material particles to which the phosphate compound is adhered at 500&#xb0; C. to 700&#xb0; C.

Growing community of inventors

Tokushima, Japan

Masaki Kondo