Abstract: An optical device includes a support portion a movable unit and a pair of torsion bars disposed on both sides of the movable unit on a first axis. The movable unit includes a main body portion, a ring-shaped portion surrounding the main body portion when viewed from a predetermined direction perpendicular to the first axis, two connection portions connecting the main body portion and the ring-shaped portion to each other, and a rib portion provided to the main body portion. Each of the two connection portions includes two connection regions that are separated from each other by a space and the each of the two connection region connects the main body portion and the ring-shaped portion to each other. The rib portion includes four extending portions radially extending between a center of the main body portion and the four connection regions respectively when viewed from the predetermined direction.

Abstract: A method of producing a nitride fluorescent material including a step of first heat-treating a first compound containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr, Ca and Mg, a second compound containing at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and a Si-containing compound, in an atmosphere containing nitrogen to obtain a calcined product of raw materials, and a step of second heat-treating the calcined product of raw materials, a Ba-containing compound, a Si-containing compound, and optionally a third compound containing at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and optionally a fourth compound containing at least one alkaline earth metal element selected from the group consisting of Sr, Ca and Mg, in an atmosphere containing nitrogen to obtain a nitride fluorescent material is provided, wherein the ratio of the charge-in molar amount of Ba to the total charge-in molar amount of at least one

Abstract: A method of producing a nitride fluorescent material including a step of first heat-treating a first compound containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr, Ca and Mg, a second compound containing at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and a Si-containing compound, in an atmosphere containing nitrogen to obtain a calcined product of raw materials, and a step of second heat-treating the calcined product of raw materials, a Ba-containing compound, a Si-containing compound, and optionally a third compound containing at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and optionally a fourth compound containing at least one alkaline earth metal element selected from the group consisting of Sr, Ca and Mg, in an atmosphere containing nitrogen to obtain a nitride fluorescent material is provided, wherein the ratio of the charge-in molar amount of Ba to the total charge-in molar amount of at least one

Abstract: A method of producing a nitride fluorescent material including a step of first heat-treating a first compound containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr, Ca and Mg, a second compound containing at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and a Si-containing compound, in an atmosphere containing nitrogen to obtain a calcined product of raw materials, and a step of second heat-treating the calcined product of raw materials, a Ba-containing compound, a Si-containing compound, and optionally a third compound containing at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and optionally a fourth compound containing at least one alkaline earth metal element selected from the group consisting of Sr, Ca and Mg, in an atmosphere containing nitrogen to obtain a nitride fluorescent material is provided, wherein the ratio of the charge-in molar amount of Ba to the total charge-in molar amount of at least one

Abstract: A method of producing a nitride fluorescent material having relatively high light emission intensity is provided. The method of producing a nitride fluorescent material includes preparing a calcined product having a composition containing at least one first element selected from the group consisting of Ba, Sr, Ca, and Mg, at least one second element selected from the group consisting of Eu, Ce, Tb, and Mn, and Si and N, and bringing the calcined product into contact with a fluorine-containing substance at a temperature in a range of ?20° C. or higher and lower than 150° C.

Abstract: A method of producing a nitride fluorescent material including a step of first heat-treating a first compound containing at least one alkaline earth metal element selected from the group consisting of Ba, Sr, Ca and Mg, a second compound containing at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and a Si-containing compound, in an atmosphere containing nitrogen to obtain a calcined product of raw materials, and a step of second heat-treating the calcined product of raw materials, a Ba-containing compound, a Si-containing compound, and optionally a third compound containing at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and optionally a fourth compound containing at least one alkaline earth metal element selected from the group consisting of Sr, Ca and Mg, in an atmosphere containing nitrogen to obtain a nitride fluorescent material is provided, wherein the ratio of the charge-in molar amount of Ba to the total charge-in molar amount of at least one

Abstract: A method of producing a nitride fluorescent material having relatively high light emission intensity is provided. The method of producing a nitride fluorescent material includes preparing a calcined product having a composition containing at least one first element selected from the group consisting of Ba, Sr, Ca, and Mg, at least one second element selected from the group consisting of Eu, Ce, Tb, and Mn, and Si and N, and bringing the calcined product into contact with a fluorine-containing substance at a temperature in a range of ?20° C. or higher and lower than 150° C.

Abstract: A light emitting device includes a light emitting element, a molded member, and a sealing member. The light emitting element is arranged on or above the molded member. The sealing member covers the light emitting element. The sealing member contains a phosphor, and a filler material. The phosphor can be excited by light of the light emitting element, and emit luminescent radiation. The filler material contains neodymium hydroxide, neodymium aluminate or neodymium silicate. The filler material absorbs a part of the spectrum of the mixed light of the light emitting element and the phosphor so that the other parts of the spectrum of this mixed light are extracted from the light emitting device.

Abstract: A light emitting device includes a light emitting element, a molded member, and a sealing member. The light emitting element is arranged on or above the molded member. The sealing member covers the light emitting element. The sealing member contains a phosphor, and a filler material. The phosphor can be excited by light of the light emitting element, and emit luminescent radiation. The filler material contains neodymium hydroxide, neodymium aluminate or neodymium silicate. The filler material absorbs a part of the spectrum of the mixed light of the light emitting element and the phosphor so that the other parts of the spectrum of this mixed light are extracted from the light emitting device.