Ngk Spark Plug Company, Limited

Shohei Takaku

Yusuke Katsu

Tsuneyuki Ito

Takeshi Mitsuoka

Jun Moteki

Tomoo Tanaka

Hiroki Takeuchi

Hideto Yamada

Toshiaki Kurahashi

Shinji Ban

Hiroki Yamauchi

Yosuke Yatsuya

Yuki Shimura

A fluorescent plate including a fluorescent phase which emits fluorescence by excitation light, and a plurality of voids, wherein, in a cross section of the fluorescent plate including cross sections of the voids, voids having an equivalent circle diameter of 0.4 micrometers or greater and 50 micrometers or smaller have a standard deviation in equivalent circle diameter of 1.5 or less.

Fluorescent plate, wavelength conversion member, and light source device

One aspect of the disclosure provides an optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, AlOcrystal grains and crystal grains represented by formula (Y,A)BO:Ce. In the optical wavelength conversion member, a (Y,A)BO:Ce crystal grain has a region wherein the A concentration of a peripheral portion of the (Y,A)BO:Ce crystal grain is higher than that of an interior portion of the (Y,A)BO:Ce crystal grain. Thus, the optical wavelength conversion member exhibits high fluorescence intensity (i.e., high emission intensity) and high heat resistance (i.e., low likelihood of temperature quenching). The optical wavelength conversion member has a structure wherein the element A concentration of a peripheral portion of a (Y,A)BO:Ce crystal grain differs from that in an interior portion of the crystal grain. This structure can achieve a ceramic fluorescent body exhibiting superior fluorescent characteristics and superior thermal characteristics with varied colors of emitted light.

Optical wavelength conversion member and light-emitting device

An optical wavelength conversion device includes an optical wavelength conversion member configured to convert the wavelength of incident light; a heat dissipation member which is more excellent in heat dissipation than the optical wavelength conversion member; and a joint portion which joins the optical wavelength conversion member and the heat dissipation member together. The optical wavelength conversion member includes a plate-shaped ceramic fluorescent body and a reflecting film disposed on a heat dissipation member-side surface of the ceramic fluorescent body. The joint portion has a thermal conductivity of 120 W/mK or more. The joint portion has a melting point of 240&#xb0; C. or higher.

Optical wavelength conversion device

An optical wavelength conversion member () provided with a ceramic plate () which is configured from a polycrystalline body that is mainly composed of AlOand a component represented by ABO:Ce; and each of A and B in ABOrepresents at least one element selected from the element groups described below. In addition, a dielectric multilayer film () which transmits a specific wavelength and reflects another specific wavelength is formed on a light incident surface () of the ceramic plate (). The ceramic plate () has a porosity of 2% by volume or less, while having an average surface roughness (an arithmetic mean roughness Sa) of 0.5 &#x3bc;m or less. A: Sc, Y and lanthanoids (excluding Ce) B: Al and Ga. Also disclosed is a light-emitting device including the optical wavelength conversion member.

Light wavelength conversion member and light emitting device

A method for producing an optical wavelength conversion member () composed of a sintered body containing, as main components, AlOand a component represented by formula ABO:Ce; an optical wavelength conversion member; an optical wavelength conversion component including the optical wavelength conversion member; and a light-emitting device including the optical wavelength conversion member or the optical wavelength conversion component. The production method of the sintered body includes firing in a firing atmosphere having a pressure of 10Pa or more and an oxygen concentration of 0.8 vol. % or more and less than 25 vol. %.

Method for producing light wavelength conversion member, light wavelength conversion member, light wavelength conversion component and light emitting device

An optical wavelength conversion member and a light-emitting device including the optical wavelength conversion member. The light-emitting device () includes a container (), a light-emitting element (), and an optical wavelength conversion member (). The optical wavelength conversion member () is composed of a polycrystalline ceramic sintered body containing, as main components, AlOcrystal grains and crystal grains of a component represented by formula ABO:Ce. Specifically, A and B of the ABOindividually represent at least one element selected from the following element groups: A: Sc, Y, and lanthanoids (except for Ce), and B: Al and Ga; the at least one element selected from the element groups is present in each crystal grain and the crystal grain boundary of the ceramic sintered body; and the element concentration of the crystal grain boundary is higher than the element concentration of the crystal grain.

An optical wavelength conversion member and a light-emitting device including the optical wavelength conversion member. The optical wavelength conversion member () is formed of a ceramic sintered body having a fluorescent phase containing fluorescent crystal grains as a main component and a translucent phase containing translucent crystal grains as a main component. Crystal grains of the fluorescent phase have a composition represented by formula ABO:Ce, where the element A is selected from Sc, Y, and lanthanoids (except for Ce), and the element B is selected from Al and Ga. In the optical wavelength conversion member (), 0.3&#x3c;a&#x3c;34 and 300 &#x3bc;m&#x3c;y&#x3c;1,050 &#x3bc;m are satisfied, wherein a represents the area ratio of the translucent phase to the fluorescent phase in a cross section of the optical wavelength conversion member (), and y represents the interfacial length of the fluorescent phase.

An optical wavelength conversion member including a polycrystalline ceramic sintered body containing, as main components, AlOcrystal grains and crystal grains of a component represented by formula ABO:Ce, wherein A is at least one element selected from Sc, Y and lanthanoids (except for Ce), and B is at least one element selected from Al and Ga. Further, the following relations are satisfied: 0%&#x2264;X&#x2264;25%, 9%&#x2264;Y&#x2264;45%, and 48%&#x2264;Z&#x2264;90%, wherein X represents a proportion corresponding to the ratio a/N, Y represents a proportion corresponding to the ratio b/N, and Z represents a proportion corresponding to the ratio c/N and a, b, c and N are as defined herein. Also disclosed is a light-emitting device including the optical wavelength conversion member.

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Komaki, Japan

Shohei Takaku